阅读说明：本技术 发光器、发光器件、光学装置和信息处理设备 (Light emitter, light emitting device, optical device, and information processing apparatus ) 是由 稻田智志 大野健一 皆见健史 大塚勤 樋口贵史 于 2019-09-03 设计创作，主要内容包括：一种发光器、发光器件、光学设备和信息处理设备,该发光器包括：基板；电容器,该电容器被设置在所述基板上；光源,该光源被设置在所述基板上并且被供应来自所述电容器中累积的电荷的驱动电流；覆盖部,该覆盖部被从所述光源发射的光透射通过并且被设置在所述光源的光轴方向上；以及支撑部,该支撑部被设置在所述基板的除了所述电容器和所述光源之间的部分之外的部分上并且支撑所述覆盖部。(A light emitter, a light emitting device, an optical apparatus, and an information processing apparatus, the light emitter comprising: a substrate; a capacitor disposed on the substrate; a light source that is provided on the substrate and is supplied with a drive current from the electric charge accumulated in the capacitor; a cover portion that is transmitted through by light emitted from the light source and is disposed in an optical axis direction of the light source; and a support portion that is provided on a portion of the substrate other than a portion between the capacitor and the light source and supports the cover portion.)

1. A light emitter, comprising:

a substrate;

a capacitor disposed on the substrate;

a light source that is provided on the substrate and is supplied with a drive current from the electric charge accumulated in the capacitor;

a cover portion that is transmitted through by light emitted from the light source and is disposed in an optical axis direction of the light source; and

a support portion that is provided on a portion of the substrate other than a portion between the capacitor and the light source and supports the cover portion.

2. The light emitter of claim 1,

the light source comprises a plurality of light-emitting elements,

the cover portion is a diffusion plate which diffuses and transmits light emitted from the light emitting element, and

an end portion of the side of the cover portion where the support portion for the cover portion is not provided is provided so as to transmit light of which emission intensity from a light emitting element provided at the end portion of the side of the light source where the support portion is not provided is 50% or more.

3. The light emitter according to claim 2, wherein an end portion of the cover portion on a side where the support portion for the cover portion is not provided is provided so as to transmit light with an emission intensity of 0.1% or more from a light emitting element of the light source provided at the end portion on the side where the support portion is not provided.

4. The light emitter according to any one of claims 1 to 3, wherein the cover covers at least a portion of a surface of the capacitor.

5. The light emitter according to claim 4, wherein the substrate further includes a circuit member on the substrate not covered by the cover in addition to the capacitor.

6. The light emitter of claim 1, wherein the support is a wall disposed around the light source and the electrical container.

7. The light emitter of claim 6, further comprising:

a blocking portion provided to extend from the wall of the supporting portion of the capacitor side toward the light source side and block transmission of light.

8. The light emitter according to claim 7, wherein the blocking portion and the supporting portion are formed as a single member.

9. The light emitter of claim 3, further comprising:

a beam portion provided at an end of the covering portion of the capacitor side to extend from the covering portion side toward the capacitor side.

10. The light emitter of claim 9, wherein the beam portion comprises a member that blocks transmission of light from the light source.

11. The light emitter according to any one of claims 9 to 10, wherein the beam portion and the support portion are formed as a single member.

12. A light emitter, comprising:

a substrate;

a capacitor disposed on the substrate;

a light source that is provided on the substrate and is supplied with a drive current from the electric charge accumulated in the capacitor;

a cover portion that is transmitted through by light emitted from the light source and is disposed in an optical axis direction of the light source; and

a support portion that is provided on the substrate, has a portion that is located between the capacitor and the light source and is thinner than other portions, and supports the cover portion.

13. A light emitting device, comprising:

the light emitter according to any one of claims 1 to 12; and

a housing accommodating the light emitter, wherein,

the cover portion of the light emitter is a diffusion plate, and

the case includes a transmission part plate that transmits light generated by diffusing light from the light source in the light emitter with the diffusion plate.

14. The light emitting device of claim 13, wherein a distance between the light source in the light emitter and the capacitor is smaller than a distance between the light source and the transmissive part plate.

15. An optical device, comprising:

the light emitter according to any one of claims 1 to 12; and

a light receiving part receiving light emitted from the light source in the light emitter and reflected by a measurement target,

the light receiving part outputs a signal corresponding to a time from when the light source emits light until the light receiving part receives the light.

16. An information processing apparatus, comprising:

the optical device of claim 15; and

a shape specifying section that specifies a three-dimensional shape of the measurement target based on light emitted from the light source in the optical device, reflected by the measurement target, and received by the light receiving section in the optical device.

17. The information processing apparatus according to claim 16, further comprising:

an authentication processing section that performs an authentication process for use of the information processing apparatus based on a result of the designation by the shape designation section.

Technical Field

The invention relates to a light emitter, a light emitting device, an optical apparatus, and an information processing apparatus.

Background

JP- ｃA-2018-32654 discloses ｃA vertical resonator type light emitting element module including ｃA plurality of vertical resonator type light emitting elements arranged on ｃA plane, having: a bonding surface that is provided in a region between laser beams from the vertical resonator-type light-emitting elements adjacent to each other on the substrate and is located on an emission direction side of the laser beams; and an outer wall facing the beam space through which the laser beam is transmitted.

Incidentally, in order to improve the measurement accuracy, a light source that performs three-dimensional sensing by a time-of-flight (ToF) method must turn on and off a large current at a higher speed. Therefore, when a wall supporting a diffusion plate that diffuses light from the light source is provided between the capacitor and the light source for discharging electric charges in order to supply a large current in a short time, it is difficult to bring the capacitor and the light source close to each other because the wall becomes an obstacle. Therefore, it is difficult to reduce the wiring inductance between the capacitor and the light source, and this becomes a constraint in the case of turning on and off the light source at high speed.

Disclosure of Invention

Technical problem

An object of the present invention is to provide a light emitter in which a light source and a capacitor can be easily disposed close to each other, as compared with a case where a wall supporting a diffusion plate similar to a wall at other portions is additionally disposed between the light source and the capacitor.

Solution to the problem

According to a first aspect of the present invention, there is provided a light emitter comprising: a substrate; a capacitor disposed on the substrate; a light source that is provided on the substrate and is supplied with a drive current from the electric charge accumulated in the capacitor; a cover portion that is transmitted through by light emitted from the light source and is disposed in an optical axis direction of the light source; and a support portion that is provided on a portion of the substrate other than a portion between the capacitor and the light source and supports the cover portion.

According to a second aspect of the present invention, in the light emitter according to the first aspect, the light source may include a plurality of light emitting elements, the cover may be a diffusion plate that diffuses and transmits light emitted from the light emitting elements, and an end portion of the cover on a side where the support portion for the cover is not provided may be provided to transmit light having an emission intensity of 50% or more from a light emitting element of the light source provided at an end portion on a side where the support portion is not provided.

According to a third aspect of the present invention, in the light emitter according to the second aspect, an end portion of the cover portion on a side where the support portion for the cover portion is not provided may be provided so as to transmit light having an emission intensity of 0.1% or more from the light emitting element of the light source provided at the end portion on the side where the support portion is not provided.

According to a fourth aspect of the present invention, in the light emitter according to any one of the first to third aspects, the cover may cover at least a part of a surface of the capacitor.

According to a fifth aspect of the present invention, in the light emitter according to the fourth aspect, the substrate includes a circuit member on the substrate which is not covered with the covering portion, in addition to the capacitor.

According to a sixth aspect of the present invention, in the light emitter according to the first aspect, the support portion may be a wall provided to surround the light source and the electric container.

According to a seventh aspect of the present invention, the light emitter according to the sixth aspect may further include: a blocking portion provided to extend from the wall of the supporting portion of the capacitor side toward the light source side and block transmission of light.

According to an eighth aspect of the present invention, in the light emitter according to the seventh aspect, the blocking portion and the supporting portion may be formed as a single member.

According to a ninth aspect of the present invention, the light emitter according to the third aspect may further include: a beam portion provided at an end of the covering portion of the capacitor side to extend from the covering portion side toward the capacitor side.

According to a tenth aspect of the present invention, in the light emitter according to the ninth aspect, the beam portion may be provided in contact with a surface of the capacitor.

According to an eleventh aspect of the present invention, in the light emitter according to the ninth or tenth aspect, the beam portion and the support portion may be formed as a single member.

According to a twelfth aspect of the present invention, there is provided a light emitter, including: a substrate; a capacitor disposed on the substrate; a light source that is provided on the substrate and is supplied with a drive current from the electric charge accumulated in the capacitor; a cover portion that is transmitted through by light emitted from the light source and is disposed in an optical axis direction of the light source; and a support portion that is provided on the substrate, has a portion that is located between the capacitor and the light source and is thinner than other portions, and supports the cover portion.

According to a thirteenth aspect of the present invention, there is provided a light emitting device comprising: the light emitter according to any one of the first to twelfth aspects; and a case that houses the light emitter, wherein the cover portion of the light emitter is a diffusion plate, and the case includes a transmission portion plate that transmits light generated by diffusing light from the light source in the light emitter with the diffusion plate.

According to a fourteenth aspect of the present invention, in the light emitting device according to the thirteenth aspect, a distance between the light source in the light emitter and the capacitor may be smaller than a distance between the light source and the transmissive part plate.

According to a fifteenth aspect of the present invention, there is provided an optical apparatus comprising: the light emitter according to any one of the first to twelfth aspects; and a light receiving part receiving light emitted from the light source in the light emitter and reflected by a measurement target, wherein the light receiving part outputs a signal corresponding to a time from when the light is emitted from the light source until the light is received by the light receiving part.

According to a sixteenth aspect of the present invention, there is provided an information processing apparatus comprising: the optical device according to the fifteenth aspect; and a shape specifying portion that specifies a three-dimensional shape of the measurement target based on light emitted from a light source in the optical device, reflected by the measurement target, and received by the light receiving portion in the optical device.

According to a seventeenth aspect of the present invention, the information processing apparatus according to the sixteenth aspect may further include an authentication processing section that performs an authentication process for use of the information processing apparatus based on a result of the designation by the shape designation section.

Advantageous effects of the invention

According to the first aspect, the light source and the capacitor can be easily arranged close to each other, compared with a case where a wall supporting the diffusion plate is additionally provided between the light source and the capacitor similarly to the wall at the other portion.

According to the second aspect, high-intensity light is prevented from being emitted to the outside without diffusion, as compared with the case where light having an intensity lower than 50% is set to be transmitted.

According to the third aspect, high-intensity light is prevented from being emitted to the outside without diffusion, as compared with the case where light having an intensity lower than 0.1% is set to be transmitted.

According to the fourth aspect, the light source and the capacitor may be arranged close to each other compared to a case where at least a part of the surface of the capacitor is not covered.

According to the fifth aspect, the area of the expensive covering portion can be reduced as compared with the case where the circuit member is also covered.

According to the sixth aspect, compared with the case where the light source and the capacitor are not surrounded, the entry of foreign matter is prevented.

According to the seventh aspect, the area of the expensive covering part can be reduced as compared with the case where the light blocking part is not provided.

According to the eighth aspect, the number of assembling steps can be reduced as compared with the case where the stopper portion and the support portion are not formed as a single member.

According to the ninth aspect, the entry of foreign matter is prevented as compared with the case where the beam portion is not provided.

According to the tenth aspect, it is possible to prevent high-intensity light from being applied to the outside, as compared with the case where the beam portion does not include any member that blocks transmission of light.

According to the eleventh aspect, the number of assembling steps can be reduced as compared with the case where the beam portion and the support portion are not formed as a single member.

According to the twelfth aspect, it is possible to enhance the support of the covering portion while the wiring inductance is reduced, as compared with the case where the wall is provided to have a constant thickness.

According to the thirteenth aspect, the diffusion plate can be prevented from being damaged, as compared with the case where the diffusion plate is exposed to the outside.

According to the fourteenth aspect, the light source and the driving section are brought close to each other, as compared with the case where the distance between the light source and the capacitor is larger than the distance between the light source and the transmission section plate.

According to a fifteenth aspect, an optical device for performing three-dimensional measurements is provided.

According to a sixteenth aspect, there is provided an information processing apparatus that can measure a three-dimensional shape.

According to a seventeenth aspect, there is provided an information processing apparatus having an authentication processing section that performs an authentication process based on a three-dimensional shape.

Drawings

Exemplary embodiments of the present invention will be described in detail based on the following drawings, in which:

fig. 1 is a view illustrating an example of an information processing apparatus;

fig. 2 is a block diagram illustrating a configuration of an information processing apparatus;

FIG. 3 is a plan view of a light source;

fig. 4 is a view for illustrating a cross-sectional structure of one VCSEL in the light source;

fig. 5A and 5B are views for illustrating an example of a diffusion plate; fig. 5A is a plan view, and fig. 5B is a sectional view taken along line VB-VB of fig. 5A;

fig. 6 is a view illustrating an example of an equivalent circuit for driving a light source by low-side driving;

fig. 7A and 7B are views for illustrating a light emitter to which the first exemplary embodiment is applied; fig. 7A is a plan view, and fig. 7B is a sectional view taken along line VIIB-VIIB in fig. 7A;

fig. 8A and 8B are views illustrating a light emitter illustrated for comparison; fig. 8A is a plan view, and fig. 8B is a sectional view taken along line VIIIB-VIIIB in fig. 8A;

fig. 9A and 9B are plan views for illustrating a modified example of the light emitter to which the first exemplary embodiment is applied; fig. 9A is a light emitter according to modification 1, and fig. 9B is a light emitter according to modification 2;

fig. 10A and 10B are views for illustrating a light emitter to which the second exemplary embodiment is applied; FIG. 10A is a plan view and FIG. 10B is a cross-sectional view taken along line XB-XB in FIG. 10A;

fig. 11A and 11B are views for illustrating a light emitter to which the third exemplary embodiment is applied; fig. 11A is a plan view, and fig. 11B is a sectional view taken along line XIB-XIB in fig. 11A;

fig. 12A and 12B are views for illustrating a light emitter as a modification of the light emitter to which the third exemplary embodiment is applied; fig. 12A is a plan view, and fig. 12B is a sectional view taken along line XIIB-XIIB in fig. 12A;

fig. 13A and 13B are views for illustrating a light emitter to which the fourth exemplary embodiment is applied; fig. 13A is a plan view, and fig. 13B is a sectional view taken along line XIIIB-XIIIB in fig. 13A; and is

Fig. 14 is a view for illustrating a sectional structure of an information processing apparatus using a light emitter.

Detailed Description

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The information processing apparatus identifies whether or not access is permitted to a user who accesses the information processing apparatus, and in many cases, use of the apparatus (information processing apparatus) is permitted only in a case where an authenticated user is a user who is permitted to access. Up to now, a method of authenticating a user using a password, a fingerprint, an iris, or the like has been adopted. In recent years, there is a demand for a higher security authentication method. As this method, authentication using a three-dimensional image such as a user face shape or the like is performed.

Here, as an example, the information processing apparatus is described as a portable information processing terminal, and is described as an apparatus that authenticates a user by recognizing the shape of a face captured as a three-dimensional image. In addition, the information processing apparatus can be applied to an information processing apparatus such as a Personal Computer (PC) in addition to the portable information terminal.

Further, the configuration, function, method, and the like described in the present exemplary embodiment can also be applied to recognition of a three-dimensional shape other than recognition of a face shape. In other words, the present exemplary embodiment may also be applied to recognize the shape of an object other than a face. In addition, the distance from the measurement target does not matter.

First exemplary embodiment

Information processing apparatus 1

Fig. 1 is a view illustrating an example of an information processing apparatus 1. As described above, the information processing apparatus 1 is a portable information processing terminal as an example.

The information processing apparatus 1 includes: a user interface section (hereinafter, referred to as UI section) 2; and an optical device 3 for acquiring a three-dimensional image. The UI section 2 has, for example, a configuration in which a display device and an input device are integrated, wherein the display device displays information to a user, and an instruction for information processing is input into the input device by an operation of the user. The display device is, for example, a liquid crystal display or an organic EL display, and the input device is, for example, a touch panel.

The optical device 3 includes a light emitter 4 and a three-dimensional sensor (hereinafter, referred to as a 3D sensor) 5. The light emitter 4 emits light toward a measurement target for acquiring a three-dimensional image, i.e., a face in the example described here. The 3D sensor 5 acquires light emitted from the light emitter 4, reflected by the face, and returned. Here, the three-dimensional image of the face is acquired based on a so-called time-of-flight (ToF) method using the time-of-flight of light. Hereinafter, even in the case of acquiring a three-dimensional image of a face, the face will be referred to as a measurement target. In addition, a three-dimensional image other than a face can be acquired. In some cases, acquiring three-dimensional images is referred to as 3D sensing.

In addition, the information processing apparatus 1 is configured as a computer including a CPU, a ROM, a RAM, and the like. In addition, the ROM includes a nonvolatile rewritable memory such as a flash memory. In addition, programs or constants accumulated in the ROM are developed in the RAM, and by running the CPU, the information processing apparatus 1 is operated and various types of information processing are executed.

Fig. 2 is a block diagram illustrating the configuration of the information processing apparatus 1.

The information processing apparatus 1 includes the above-described optical device 3, an optical device controller 8, and a system controller 9. The optical device controller 8 controls the optical device 3. In addition, the optical device controller 8 includes a shape specifying section 81. The system controller 9 controls the entire information processing apparatus 1 as a system. In addition, the system controller 9 includes an authentication processing section 91. In addition, the UI section 2, a speaker 92, a two-dimensional camera (in fig. 2, referred to as a 2D camera) 93, and the like are connected to the system controller 9. In addition, the 3D sensor 5 is an example of a light receiving section, and the optical device controller 8 is an example of a controller.

Hereinafter, a more detailed description will be given.

The light emitter 4 includes a substrate 10, a light source 20, a diffusion plate 30, a light amount monitoring light receiving element (referred to as PD in fig. 2 and subsequent drawings) 40, a driving section 50, a support section 60, and capacitors 70A and 70B. The light source 20, the PD40, the driving section 50, and the capacitors 70A and 70B are disposed on the substrate 10. In addition, the diffusion plate 30 is held at a predetermined distance from the substrate 10 by the support part 60, and is disposed to cover the light sources 20 and the PDs 40. The diffusion plate 30 is an example of a cover.

In addition, on the substrate 10, in addition to the above-described members, the 3D sensor 5, the resistance element 6, and the capacitor 7 are mounted. The resistive element 6 and the capacitor 7 are provided for operating the driving section 50 or the 3D sensor 5. In addition, one resistance element 6 and one capacitor 7 are described, respectively, but a plurality of resistance elements 6 and capacitors 7 may be mounted. In addition, in fig. 1, the 3D sensor 5 is also provided on the substrate 10, and the 3D sensor 5 may not be provided on the substrate 10.

The light source 20 in the light emitter 4 includes a plurality of light emitting elements arranged two-dimensionally in the form of a light emitting element array. As an example, the light emitting element is a vertical resonator surface emitting laser element VCSEL (vertical cavity surface emitting laser). Hereinafter, the light emitting element will be described as a vertical resonator surface emitting laser element VCSEL. The vertical resonator surface emitting laser element VCSEL will be referred to as VCSEL. The light source 20 emits light in a direction perpendicular to the substrate 10. In the case of performing three-dimensional sensing by the ToF method, the light source 20 is required to emit pulsed light equal to or greater than 100MHz and having a rise time of 1ns or less, for example, by the driving section 50. Hereinafter, the emitted pulsed light is referred to as an emission pulse. In addition, in the case of face authentication as an example, the distance of light emission is from approximately 10cm to approximately 1 m. In addition, a range for measuring the 3D shape of the measurement target is approximately 1 square meter. Hereinafter, the distance of light emission is referred to as a measurement distance, and a range for measuring the 3D shape of the measurement target is referred to as a measurement range or an irradiation range. In addition, a surface virtually set in the measurement range or the irradiation range is referred to as an irradiation surface.

Subsequently, the substrate 10, the diffusion plate 30, the PD40, the driving section 50, the supporting section 60, and the capacitors 70A and 70B in the light emitter 4 will be described. In addition, the light source 20 will be described in detail later.

The 3D sensor 5 includes a plurality of light receiving units. For example, each of the light receiving units is configured to receive reflected light from a measurement target for an emission pulse from the light source 20, and to accumulate electric charges corresponding to a time until the reflected light is received for each light receiving unit. Hereinafter, the received reflected light will be referred to as a light reception pulse. The 3D sensor 5 is configured as a device of a CMOS structure in which each light receiving unit includes two gates and a charge accumulating portion corresponding to the two gates. In addition, by alternately adding pulses to the two gates, the generated photoelectrons are transferred to either of the two charge accumulating portions at high speed. In the two charge accumulation sections, charges corresponding to a phase difference between the transmission pulse and the light reception pulse are accumulated. In addition, the 3D sensor 5 outputs, as a signal, a digital value corresponding to a phase difference between the transmission pulse and the light reception pulse for each reception unit via the AD converter. In other words, the 3D sensor 5 outputs a signal corresponding to the time after light is emitted from the light source 20 until the light is received by the 3D sensor 5. In addition, the AD converter may be provided in the 3D sensor 5, or may be provided outside the 3D sensor 5.

The shape specifying section 81 of the optical device controller 8 acquires a digital value obtained from the 3D sensor 5 in each light receiving unit, and calculates a distance to a measurement target for each light receiving unit. In addition, from the calculated distance, the 3D shape of the measurement target is specified.

In the case where the 3D shape of the measurement target specified by the shape specifying part 81 has a 3D shape accumulated in advance in a ROM or the like, the authentication processing part 91 of the system controller 9 executes authentication processing relating to use of the information processing apparatus 1. In addition, as an example, the authentication process related to the use of the information processing apparatus 1 is a process of determining whether or not the use of the information processing apparatus 1 as a device is permitted. For example, in the case where it is determined that the 3D shape of the face as the measurement target matches the shape of the face stored in the storage means such as the ROM, use of the information processing apparatus 1 is permitted including various applications and the like provided by the information processing apparatus 1.

The shape specifying section 81 and the authentication processing section 91 described above include programs as examples. Alternatively, the shape specifying section 81 and the authentication processing section 91 may further include an integrated circuit such as an ASIC or an FPGA. Further, the shape specifying section 81 and the authentication processing section 91 may include software such as a program and an integrated circuit such as an ASIC.

In fig. 2, the optical device 3, the optical device controller 8, and the system controller 9 are illustrated separately, but the system controller 9 may include the optical device controller 8. In addition, the optical device 3 may include an optical device controller 8. Further, the optical device 3, the optical device controller 8, and the system controller 9 may be integrally formed.

Before describing the light emitter 4, the light source 20, the diffusion plate 30, the PD40, the driving part 50, and the capacitors 70A and 70B forming the light emitter 4 will be described.

Arrangement of light sources 20

Fig. 3 is a plan view of the light source 20. The light source 20 has a configuration in which a plurality of VCSELs are arranged in a two-dimensional array. The rightward direction of the paper is the x-direction, and the upward direction of the paper is the y-direction. The direction counterclockwise orthogonal to the x-direction and the y-direction is the z-direction.

The VCSEL is a light emitting element that is provided with an active region that is a light emitting region between a lower multilayer film mirror and an upper multilayer film mirror stacked on a semiconductor substrate 200 and emits laser light in a direction perpendicular to the semiconductor substrate (see fig. 4 to be described later). Therefore, a two-dimensional array is easily formed. The number of VCSELs included in the light source 20 is, for example, 100 to 1000. In addition, the plurality of VCSELs are connected in parallel with each other and are driven in parallel. In addition, the above number of VCSELs is an example, and the number of VCSELs may be set in accordance with a measurement distance and a measurement range.

On the surface of the light source 20, a common anode electrode 218 is provided in the plurality of VCSELs (see fig. 4 which will be described later). In addition, the anode electrode 218 is connected to anode wirings 11A and 11B provided on the substrate 10 via bonding wires 21A and 21B. In addition, the plurality of bonding wires disposed on the upper side (+ y direction side) will be referred to as bonding wires 21A, and the plurality of bonding wires disposed on the lower side (-y direction side) will be referred to as bonding wires 21B. Here, the bonding wire 21A is connected to the anode wiring 11A, and the bonding wire 21B is connected to the anode wiring 11B. In addition, a capacitor 70A (refer to fig. 2) is connected to the anode wiring 11A, and a capacitor 70B (refer to fig. 2) is connected to the anode wiring 11B. In addition, a cathode electrode 214 (see fig. 4 to be described later) is provided on the rear surface of the light source 20 and bonded to the cathode wiring 12 with a conductive adhesive or the like, wherein the cathode electrode 214 is provided on the substrate 10. The conductive adhesive is, for example, silver paste.

Here, the anode wirings 11A and 11B are disposed in the up-down direction of the light source 20, and are connected to the anode electrode 218 through bonding wires 21A and 21B. Therefore, the current is supplied to the light source 20 in parallel with the up-down direction. When the bonding wire is disposed on one side in the upward direction or the downward direction of the anode electrode 218 and supplies current to the light source 20, the VCSEL near the bonding wire has high current density and high light intensity, and the VCSEL on the far side of the bonding wire has low current density and low light intensity. In other words, in the plurality of VCSELs of the light source 20, the intensity of emitted light tends to be deviated.

In contrast, as illustrated in fig. 3, the light source 20 is provided with anode wirings 11A and 11B in the vertical direction, and bonding wires 21A and 21B are provided so as to be connected to the anode electrode 218, so that current is supplied to the light source 20 in the vertical direction. Therefore, the intensity of light emitted from the plurality of VCSELs in the light source 20 is prevented from being deviated. In addition, only one of the anode wiring 11A and the anode wiring 11B may be used. In this case, only one of the capacitors 70A and 70B is required. In addition, in fig. 2, each of the capacitors 70A and 70B is illustrated as one capacitor, but each of the capacitors 70A and 70B may include a plurality of capacitors arranged in parallel.

VCSEL structure

Fig. 4 is a view for illustrating a cross-sectional structure of one VCSEL in the light source 20. The VCSEL is a VCSEL having a λ resonator structure. The upward direction of the paper is the z direction.

The VCSEL has the following configuration: an n-type lower distributed bragg reflector (DBR: distributed bragg reflector) 202 in which AlGaAs layers having different Al compositions are alternately overlapped with each other, an active region 206 including a quantum well layer sandwiched between an upper spacer layer and a lower spacer layer, and a p-type upper distributed bragg reflector 208 in which AlGaAs layers having different Al compositions are alternately overlapped with each other are stacked on a semiconductor substrate 200 such as n-type GaAs. Hereinafter, the distributed bragg mirror will be referred to as a DBR.

The n-type lower DBR 202 is a laminate in which Al is present_0.9Ga_0.1As layers and GaAs layers are formed in a pair, each layer having a thickness of lambda/4 n_r(and λ is the oscillation wavelength and n_rIs a refractive index of a medium), and these layers are alternately stacked for 40 cycles, the carrier concentration after doping silicon as an n-type impurity is, for example, 3 × 10¹⁸cm^-3。

The active region 206 has a configuration in which a lower spacer layer, a quantum well active layer, and an upper spacer layer are stacked. For example, the lower spacer layer is undoped Al_0.6Ga_0.4An As layer, a quantum well active layer is an undoped InGaAs quantum well layer and an undoped GaAs barrier layer, and an upper spacer layer is undoped Al_0.6Ga_0.4And an As layer.

The p-type upper DBR208 is a laminate in which p-type Al_0.9Ga_0.1As layers and GaAs layers are formed in a pair, each layer having a thickness of lambda/4 n_rAnd these layers are alternately stacked for 29 cycles, the carrier concentration after doping carbon as a p-type impurity is, for example, 3 × 10¹⁸cm^-3. Preferably, a contact layer made of p-type GaAs is formed at the uppermost layer of the upper DBR208, and a current confinement layer 210 of p-type AlAs is formed at the lowermost or inner side of the upper DBR 208.

A cylindrical mesa M is formed on the semiconductor substrate 200 by etching the semiconductor layers stacked from the upper DBR208 until reaching the lower DBR 202. Therefore, the current confinement layer 210 is exposed on the side surface of the mesa M. Through the oxidation step, in the current confinement layer 210, an oxidized region 210A oxidized from the side surface of the mesa M and a conductive region 210B surrounded by the oxidized region 210A are formed. In addition, in the oxidation step, since the oxidation rate of the AlAs layer is higher than that of the AlGaAs layer and the oxidized region 210A is oxidized inward from the side surface of the mesa M at substantially the same rate, the planar shape parallel to the semiconductor substrate 200 of the conductive region 210B has a shape reflecting the outer shape of the mesa M (that is, a circular shape) and the center thereof substantially matches the axial direction (chain line) of the mesa M. In addition, in the exemplary embodiment, the mesa M has a pillar structure.

On the uppermost layer of the mesa M, an annular p-side electrode 212 made of a metal in which Ti/Au or the like is laminated is formed. The p-side electrode 212 is in ohmic contact with a contact layer provided on the upper DBR 208. Inside the annular p-side electrode 212 is a light emitting port 212A through which laser light is emitted to the outside. In other words, in the VCSEL, light is emitted in a direction perpendicular to the semiconductor substrate 200, and the axial direction of the mesa M is the optical axis. Further, on the rear surface of the semiconductor substrate 200, a cathode electrode 214 is formed as an n-side electrode. In addition, the surface of the upper DBR208 inside the p-side electrode 212 is a light emitting surface.

In addition, an insulating layer 216 is provided so as to cover the surface of the mesa M, except for the light emitting port 212A and a portion of an anode electrode (an anode electrode 218 to be described later) connecting the p-side electrode 212. In addition, the anode electrode 218 is disposed in ohmic contact with the p-side electrode 212 except for the light emitting port 212A. In addition, the anode electrode 218 is provided in common for a plurality of VCSELs. In other words, each of the p-side electrodes 212 is connected in parallel to a plurality of VCSELs forming the light source 20 through the anode electrode 218.

In addition, the VCSEL can oscillate in a single transverse mode, and can oscillate in a multi-transverse mode (multimode). For example, the light output of one of the VCSELs is 4mW to 8 mW.

The VCSEL group 22A located at the end on the + y direction side is a VCSEL on the capacitor 70A side illustrated in fig. 7A and 7B to be described later, and the VCSEL group 22B located at the end on the-y direction side is a VCSEL on the capacitor 70B side illustrated in fig. 7A and 7B to be described later.

Arrangement of the diffuser plate 30

Fig. 5A and 5B are views for illustrating an example of the diffusion plate 30. Fig. 5A is a plan view, and fig. 5B is a sectional view taken along line VB-VB of fig. 5A. In fig. 5A, the rightward direction of the paper surface is the x direction, and the upward direction of the paper surface is the y direction. The direction counterclockwise orthogonal to the x-direction and the y-direction is the z-direction. Therefore, in fig. 5B, the rightward direction of the paper surface is the x direction, and the upward direction of the paper surface is the z direction.

As illustrated in fig. 5B, the diffuser plate 30 has two surfaces parallel to each other, and includes a resin layer 32, on which irregularities for diffusing light toward one surface (here, the-z direction side as the rear surface) of the flat glass substrate 31 are formed on the resin layer 32. The diffusion plate 30 further expands the expansion angle of light incident from the VCSELs of the light source 20 and emits the light. In other words, irregularities formed on the resin layer 32 of the diffuser plate 30 refract or scatter light, and the spread angle β of emitted light is made larger than the spread angle α of incident light. In other words, as illustrated in fig. 5A and 5B, the spread angle β of the light emitted from the diffusion plate 30 transmitted through the diffusion plate 30 becomes larger than the spread angle α of the light emitted from the VCSEL (α < β). Therefore, when the diffusion plate 30 is used, the area of the surface irradiated with light emitted from the light source 20 is larger than when the diffusion plate 30 is not used. In addition, the optical density on the irradiated surface decreases. In addition, the optical density means an irradiance per unit area, and the spread angles α and β are full widths at half maximum (FWHM).

In addition, the diffusion plate 30 has, for example, a square planar shape having a width W in the x direction_xAnd a longitudinal width W in the y-direction_yIs 1mm to 10mm, and has a thickness t in the z direction_dIs 0.1mm to 1 mm. In addition, the end on the + y direction side is an end 33A of the diffusion plate 30, and the end on the-y direction side is an end 33B of the diffusion plate 30. As will be described later with reference to fig. 7A and 7B, the end portion 33A is on the capacitor 70A side, and the end portion 33B is on the capacitor 70B side. In addition, the planar shape of the diffusion plate 30 may be other shapes such as a polygonal shape or a circular shape. In addition, in the case of the above size and shape, particularly, a light diffusion member is provided, the lightThe diffusion member is suitable for face authentication of the portable information terminal or measurement of a relatively short distance of approximately several meters.

PD 40

The PD40 is a photodiode made of silicon or the like for outputting an electric signal corresponding to the amount of light it receives (hereinafter, referred to as the received light amount). The PD40 is provided to receive light emitted from the light source 20 and reflected by the rear surface (a surface in the-z direction in fig. 7B to be described later) of the diffusion plate 30. The light source 20 is controlled to maintain a predetermined light amount based on the light amount received by the PD40 and emit light. In other words, as will be described later, the optical device controller 8 monitors the amount of light received by the PD40, controls the driving section 50, and controls the amount of light emitted from the light source 20.

Drive section 50 and capacitors 70A and 70B

In the case where it is desired to drive the light source 20 at a higher speed, low-side driving is preferably performed. The low-side drive refers to a configuration in which a drive element such as a MOS transistor is located on the downstream side of a current path with respect to a drive target such as a VCSEL. In contrast, a configuration in which the driving element is on the upstream side is referred to as high-side driving.

Fig. 6 is a view illustrating an example of an equivalent circuit for driving the light source 20 by low-side driving. In fig. 6, the VCSEL of the light source 20, the driving section 50, the capacitors 70A and 70B, the power supply 82, the PD40, and the detection resistance element 41 for detecting the current flowing through the PD40 are illustrated. In addition, the capacitors 70A and 70B are connected in parallel to the power supply 82.

The power supply 82 is provided in the optical device controller 8 illustrated in fig. 2. The power supply 82 generates a DC voltage with the + side at the supply potential and the-side at ground potential. A power supply potential is supplied to the power supply line 83, and a ground potential is supplied to the ground line 84.

The light source 20 has a configuration in which a plurality of VCSELs are connected in parallel with each other as described above. An anode electrode 218 (refer to fig. 4) of the VCSEL is connected to the power supply line 83 via anode wirings 11A and 11B provided on the substrate 10.

The driving section 50 includes an n-channel MOS transistor 51 and a signal generating circuit 52 to turn on and off the MOS transistor 51. The drain of the MOS transistor 51 is connected to a cathode electrode 214 (see fig. 4) of the VCSEL via a cathode wiring 12 provided on the substrate 10. The source of MOS transistor 51 is connected to ground 84. In addition, a gate of the MOS transistor 51 is connected to the signal generation circuit 52. In other words, the VCSEL of the light source 20 and the MOS transistor 51 of the driving section 50 are connected in series with each other between the power supply line 83 and the ground line 84. By controlling the optical device controller 8, the signal generation circuit 52 generates an "H level" signal for turning on the MOS transistor 51 and an "L level" signal for turning off the MOS transistor 51.

In the capacitors 70A and 70B, one terminal is connected to the power supply line 83, and the other terminal is connected to the ground line 84. In addition, the capacitors 70A and 70B include, for example, electrolytic capacitors or ceramic capacitors.

In the PD40, the cathode is connected to the power supply line 83, and the anode is connected to one terminal of the detection resistance element 41. In addition, the other terminal of the detection resistance element 41 is connected to the ground line 84. In other words, the PD40 and the detection resistance element 41 are connected in series with each other between the power supply line 83 and the ground line 84. In addition, an output terminal 42 as a connection point between the PD40 and the detection resistance element 41 is connected to the optical device controller 8.

Next, a driving method of the light source 20 as a low-side drive will be described.

First, the signal generated by the signal generation circuit 52 in the drive section 50 is "L level". In this case, the MOS transistor 51 is turned off. In other words, a current does not flow between the source and the drain of the MOS transistor 51. Therefore, current does not flow to the VCSELs connected in series to each other. The VCSEL does not emit light.

At this time, the capacitors 70A and 70B are charged by the power supply 82. In other words, one terminal of the capacitors 70A and 70B is a power supply potential and the other terminal is a ground potential. In the capacitors 70A and 70B, electric charges determined by the capacitance, the power supply voltage (power supply potential-ground potential), and time are accumulated.

Next, when the signal generated by the signal generation circuit 52 in the drive section 50 is "H level", the MOS transistor 51 is turned ON from OFF. Then, the electric charge accumulated in the capacitor 70 flows to (is discharged to) the MOS transistor 51 and the VCSEL connected in series to each other, and the VCSEL emits light.

In addition, when the signal generated by the signal generation circuit 52 in the drive section 50 is at "L level", the MOS transistor 51 is turned from ON to OFF. Thus, the VCSEL stops emitting light. Then, the power supply 82 restores the charge accumulation in the capacitors 70A and 70B.

As described above, the non-light emission and the light emission, which are the light emission stop of the VCSEL, are repeated every time the signal output from the signal generation circuit 52 becomes "L level" and "H level". In other words, the optical pulses from the VCSEL are emitted.

In addition, in the case where the capacitors 70A and 70B are not provided, electric charges (current) can be directly supplied from the power supply 82 to the VCSEL, but by accumulating the electric charges in the capacitors 70A and 70B, releasing the accumulated electric charges by the switch of the MOS transistor 51, and quickly supplying the current to the VCSEL, the rise time of light emission of the VCSEL is shortened. Further, when the distance between the light source 20 and the capacitors 70A and 70B is reduced so that the inductance of the wiring is reduced, the light source 20 can be turned on and off at high speed. Here, as shown in fig. 3, electric charges are supplied from the + y-direction side to the light source 20 through the capacitor 70A, and are supplied from the-y-direction side through the capacitor 70B. In addition, the distance between the light source 20 and the capacitors 70A and 70B may preferably be equal to or less than 1 mm.

The PD40 is connected between the power supply line 83 and the ground line 84 in the reverse direction via the detection resistance element 41. Therefore, no current flows in the non-light emitting state. When the PD40 receives the light portion reflected by the diffusion plate 30 among the light emitted from the VCSEL, a current corresponding to the received light amount flows in the PD 40. Therefore, the current flowing through the PD40 is measured by the voltage of the output terminal 42, and the light intensity of the light source 20 is detected. Here, the optical device controller 8 performs control such that the light intensity of the light source 20 is a predetermined light intensity according to the amount of light received by the PD 40. In other words, in the case where the light intensity of the light source 20 is lower than the predetermined light intensity, the optical device controller 8 increases the amount of electric charges accumulated in the capacitors 70A and 70B by increasing the power supply potential of the power supply 82, and increases the current flowing to the VCSEL. Further, in the case where the light intensity of the light source 20 is higher than the predetermined light intensity, by lowering the power supply potential of the power supply 82, the optical device controller 8 reduces the amount of electric charges accumulated in the capacitors 70A and 70B, and reduces the current flowing to the VCSEL. In this way, the light intensity of the light source 20 is controlled.

In addition, in the case where the amount of light received by the PD40 has been extremely reduced, there is a problem in that the light emitted from the light source 20 is directly emitted to the outside when the diffusion plate 30 is detached or damaged. In this case, the optical device controller 8 reduces the light intensity of the light source 20. For example, the light source 20 stops emitting light, that is, stops irradiating the measurement target with light.

The substrate 10 is, for example, a multilayer substrate having three layers. In other words, the substrate 10 includes a first conductive layer, a second conductive layer, and a third conductive layer from the side where the light source 20 or the driving part 50 is mounted. Further, an insulating layer is provided between the first conductive layer and the second conductive layer and between the second conductive layer and the third conductive layer. For example, the third conductive layer is a power supply line 83 and the second conductive layer is a ground line 84. In addition, through the first conductive layer, a circuit pattern of terminals or the like to which the anode wirings 11A and 11B, the cathode wiring 12, the PD40, the detection resistance element 41, the capacitors 70A and 70B, and the like of the light source 20 are connected is formed. The first conductive layer, the second conductive layer, and the third conductive layer are made of a metal such as copper (Cu) or silver (Ag) or a conductive material such as a conductive paste containing a metal. The insulating layer is made of, for example, epoxy resin or ceramic.

The power supply line 83 of the third conductive layer is connected to the anode wirings 11A and 11B provided on the first conductive layer through a via hole, a terminal to which the cathode of the PD40 is connected through a via hole, and the like, and a terminal to which the power supply line 83 of the capacitors 70A and 70B is connected. Similarly, the ground line 84 of the second conductive layer is connected to a terminal to which the source of the MOS transistor 51 of the driving section 50 is connected, a terminal to which the ground line 84 of the detection resistance element 41 is connected, and the like through a through hole. Therefore, the power supply line 83 made of the third conductive layer and the ground line 84 made of the second conductive layer prevent variations in the power supply potential and the ground potential.

Light emitter 4

Next, the light emitter 4 will be described in detail.

Fig. 7A and 7B are views for illustrating the light emitter 4 to which the first exemplary embodiment is applied. Fig. 7A is a plan view, and fig. 7B is a sectional view taken along line VIIB-VIIB of fig. 7A. Here, in fig. 7A, the rightward direction of the paper surface is the x direction, and the upward direction of the paper surface is the y direction. The direction counterclockwise orthogonal to the x-direction and the y-direction is the z-direction. Therefore, in fig. 7B, the rightward direction of the paper surface is the y direction, and the upward direction of the paper surface is the z direction. This also applies to the following similar figures.

As described above, the light emitter 4 includes the substrate 10, the light source 20, the diffusion plate 30, the PD40, the driving part 50, and the supporting part 60. In addition, on the substrate 10 of the light emitter 4, circuit members such as the 3D sensor 5, the resistance element 6, and the capacitor 7 are also mounted. In addition, as described above, the circuit pattern connecting the anode wirings 11A and 11B, the cathode wiring 12, the light source 20, the PD40, the driving part 50, the 3D sensor 5, the resistance element 6, the capacitor 7, and the like is provided on the substrate 10.

In the light emitter 4, for example, the PD40, the light source 20, and the driving section 50 are disposed on the substrate 10 in the + x direction in this order. In addition, the capacitors 70A and 70B are respectively provided so as to sandwich the light source 20 in the ± y direction of the light source 20 of the substrate 10.

The diffusion plate 30 is provided to cover the light source 20 and the PD 40. In addition, the diffusion plate 30 does not cover the driving part 50, the capacitors 70A and 70B, the 3D sensor 5, the resistance element 6, and the capacitor 7. In other words, the circuit member not covered with the diffusion plate 30 is mounted on the substrate 10. The diffusion plate 30 covers a portion of the substrate 10, not the entire substrate 10.

The light source 20 may be directly mounted on the substrate 10 on which the above-described circuit pattern and the like are formed. In addition, the light source 20 is disposed on a heat dissipation substrate made of a heat dissipation base material such as aluminum oxide or aluminum nitride, and the heat dissipation substrate may be mounted on the substrate 10. In addition, the light source 20 may be mounted on a substrate, a portion of which the light source 20 is mounted is recessed. Here, the substrate 10 includes a circuit board having a circuit pattern, a circuit board including a heat dissipation substrate, a substrate recessed for mounting the light source 20, and the like.

As illustrated in fig. 7B, the diffusion plate 30 is supported by the support 60 at a predetermined distance from the light source 20. The support portion 60 includes wall portions 61A and 61B. The wall portion 61A is provided on the PD40 side, and the wall portion 61B is provided on the driving section 50 side. The wall portions 61A and 61B form the yz plane. In other words, in the support portion 60, the wall portion is not provided on the side where the capacitor 70A is provided (referred to as the capacitor 70A side, and this will apply to the other cases) and the capacitor 70B side. In other words, between the light source 20 and the capacitors 70A and 70B, no wall portion is provided. Here, the case where no wall portion is provided between the light source 20 and the capacitors 70A and 70B is referred to as the case where the support portion 60 is not provided between the light source 20 and the capacitors 70A and 70B. In addition, in the case where the wall portions 61A and 61B are not distinguished, respectively, there is a case where the wall portions 61A and 61B are referred to as wall portions or walls.

In addition, as illustrated in fig. 7A and 7B, both sides of the diffusion plate 30 having a square planar shape are supported by the wall portions 61A and 61B of the support portion 60. The support portion 60 is, for example, a single member integrally molded with a resin material such as a liquid crystal polymer or a ceramic, and the wall portion has a thickness of 300 μm and a height of 450 to 550 μm. In addition, the support portion 60 is made black or the like so as to absorb light emitted from the light source 20. In addition, one end face of the wall portion of the support portion 60 is joined to the substrate 10, and the other end face is joined to the diffusion plate 30.

As illustrated in fig. 7A and 7B, between the light source 20 and the capacitors 70A and 70B, no wall portion, i.e., the support portion 60 is provided. In this structure, the light source 20 and the capacitors 70A and 70B are disposed close to each other, so that wiring for supplying current for light emission from the capacitors 70A and 70B to the light source 20 is shortened, and wiring inductance is reduced. Therefore, the light source 20 is turned on and off at high speed.

As illustrated in fig. 7B, the PD40 is covered with the diffusion plate 30 together with the light source 20. Accordingly, the PD40 receives a part of the light reflected by the diffusion plate 30 among the light emitted from the light source 20. Therefore, as described in fig. 6, the PD40 detects (monitors) the intensity of the light emitted from the light source 20.

Light emitter 4 'for comparison'

Fig. 8A and 8B are views for illustrating the light emitter 4' illustrated for comparison. Fig. 8A is a plan view, and fig. 8B is a sectional view taken along line VIIIB-VIIIB of fig. 8A. Hereinafter, a portion different from the light emitter 4 to which the first exemplary embodiment illustrated in fig. 7A and 7B is applied will be described.

In the light emitter 4 'illustrated in fig. 8A and 8B, the support portion 60' includes wall portions 62A and 62B in addition to the wall portions 61A and 61B. Wall portion 62A is disposed between light source 20 and capacitor 70A, wall portion 62B is disposed between light source 20 and capacitor 70B, and both wall portion 62A and wall portion 62B form the xz plane. In addition, the wall portions 61A, 61B, 62A, and 62B are connected to each other on the side surfaces. In other words, the cross-sectional shape of the support portion 60 in the z direction forms the sides of a square. In addition, in the light emitter 4', the light source 20 and the PD40 are surrounded by wall portions 61A, 61B, 62A, and 62B of the support portion 60. In the light emitter 4', the distance between the light source 20 and the capacitors 70A and 70B should be set larger than the thickness of the wall portions 62A and 62B due to the wall portion 62A existing between the light source 20 and the capacitor 70A and the wall portion 62B existing between the light source 20 and the capacitor 70B. As described above, when the thickness of the wall portion is 300 μm, the wiring for supplying the current for light emission from the capacitors 70A and 70B to the light source 20 becomes longer than 300 μm corresponding to at least the thickness of the wall portions 62A and 62B. Therefore, there is a problem in that in the case of turning on and off the light source 20 at a high speed, an increase in the wiring inductance becomes a constraint.

The light emitter 4 to which the first exemplary embodiment illustrated in fig. 7A and 7B is applied does not include a support portion between the light source 20 and the capacitors 70A and 70B. Therefore, as indicated by arrows in fig. 7B, there is a problem that light emitted from the light source 20 to the capacitor 70A side and the capacitor 70B side is emitted to the outside without being transmitted through the diffusion plate 30. In particular, there is a problem that light having high intensity is emitted to the outside from the VCSEL groups 22A and 22B illustrated as being surrounded by a broken line in fig. 3 and disposed in the end portion on the driving portion 50 side of the light source 20. In addition, the light intensity is sometimes referred to as emission intensity.

Here, as illustrated in fig. 7B, the position of the end 33A of the diffusion plate 30 on the capacitor 70A side may preferably be set so that light having an intensity (emission intensity) of 50% or more and emitted from the VCSEL group 22A is incident on the diffusion plate 30, and the position of the end 33B of the diffusion plate 30 on the capacitor 70B side may preferably be set so that light having an intensity (emission intensity) of 50% and emitted from the VCSEL group 22B is incident on the diffusion plate 30. With such a setting, the intensity of light emitted to the outside without being diffused by the diffusion plate 30 is set to be lower than 50% of the intensity of light emitted by the VCSEL (emission intensity). With such an arrangement, application of high-intensity light from the light source 20 to the measurement target is prevented.

Further, the position of the end portion 33A of the diffusion plate 30 on the capacitor 70A side may be set so that light having an intensity (emission intensity) of 0.1% or more and emitted from the VCSEL group 22A is incident on the diffusion plate 30, and the position of the end portion 33B of the diffusion plate 30 on the capacitor 70B side may be set so that light having an intensity of 0.1% or more and emitted from the VCSEL group 22B is incident on the diffusion plate 30. With such a setting, the intensity of light emitted to the outside without being diffused by the diffusion plate 30 is set to be lower than 0.1% of the intensity of light emitted by the VCSEL (emission intensity). With such an arrangement, application of high-intensity light from the light source 20 to the measurement target is prevented. In this case, when the spread angle of the light emitted by the VSCEL is the same, the end portions 33A and 33B of the diffuser plate 30 may extend to the side of the support wall where the support portion 60 is not provided, that is, the capacitor 70A and 70B sides.

Modification of light emitter 4

A modified example of the light emitter 4 to which the first exemplary embodiment illustrated in fig. 7A and 7B is applied will be described.

In the light emitter 4, the diffusion plate 30 covers the light source 20 and the PD40, and does not cover the capacitors 70A and 70B. In a modification to which the light emitter 4 of the first exemplary embodiment is applied, the diffusion plate 30 covers a part of the surfaces of the capacitors 70A and 70B.

Fig. 9A and 9B are plan views for illustrating a modified example of the light emitter 4 to which the first exemplary embodiment is applied. Fig. 9A is a light emitter 4-1 according to modification 1, and fig. 9B is a light emitter 4-2 according to modification 2. In addition, in fig. 9A and 9B, only the light source 20, the diffusion plate 30, the PD40, and the support 60 are referred to. In addition, the same portions as those of the light emitter 4 illustrated in fig. 7A and 7B will be given the same reference numerals, and a description thereof will be omitted.

In the light emitter 4-1 according to modification 1 illustrated in fig. 9A, the diffusion plate 30 is suspended to the capacitor 70A and 70B side and also covers a part of the capacitors 70A and 70B. In the light emitter 4-2 according to modification 2 illustrated in fig. 9B, the diffusion plate 30 is suspended from the capacitors 70A and 70B and also covers the capacitors 70A and 70B. In other words, the vertical width Wy of the diffusion plate 30 is wider than the vertical width of the light emitter 4. In addition, in the light emitters 4-1 and 4-2, the wall portions 61A and 61B of the support portion 60 are suspended to the capacitor 70A and 70B sides by the suspension of the diffusion plate 30.

In the light emitters 4-1 and 4-2, the diffusion plate 30 is suspended to the capacitor 70A and 70B side, and therefore, the distance between the VCSEL groups 22A and 22B disposed in the end portions of the light source 20 on the capacitor 70A and 70B side and the end portions 33A and 33B of the diffusion plate 30 is increased. Therefore, it is possible to easily prevent high-intensity light from being applied from the end of the diffusion plate 30. For example, alternatively, the light emitter 4-1 may be used in the case where the light transmitted through the diffusion plate 30 is equal to or higher than 50%, and the light emitter 4-2 may be used in the case where the light transmitted through the diffusion plate 30 is equal to or higher than 0.1%.

Second exemplary embodiment

In the light emitter 4A to which the second exemplary embodiment is applied, the beam portions provided on the capacitors 70A and 70B side of the diffusion plate 30 are provided from the diffusion plate 30 side toward the capacitors 70A and 70B side.

Fig. 10A and 10B are views for illustrating a light emitter 4A to which the second exemplary embodiment is applied. Fig. 10A is a plan view, and fig. 10B is a sectional view taken along line XB-XB of fig. 10A. The same portions as those of the light emitter 4 illustrated in fig. 7A and 7B will be given the same reference numerals, and a description thereof will be omitted.

As illustrated in fig. 10A, the diffusion plate 30 covers the light source 20 and the PD 40. In addition, the support portion 60A is provided with wall portions 61A and 61B for supporting both sides of the diffusion plate 30 with respect to the substrate 10. In addition, the light emitter 4A includes beam portions 65A and 65B provided from the remaining two sides of the diffusion plate 30 toward the capacitors 70A and 70B. As illustrated in fig. 10B, the upper surfaces (+ z direction side surfaces) of the beam portions 65A and 65B are joined to the diffusion plate 30. In addition, the lower surfaces (-z direction side surface) of the beam portions 65A and 65B are distant from the upper surface (+ z direction side surface) of the substrate 10. Here, the lower surfaces of the beam portions 65A and 65B face the surface of the substrate 10, but may be disposed to face the surfaces of the capacitors 70A and 70B. At this time, the lower surfaces of the beam portions 65A and 65B may be in contact with the surfaces of the capacitors 70A and 70B.

The wall portions 61A and 61B and the beam portions 65A and 65B of the support portion 60 may be formed as a single member by integral molding or the like. Therefore, the number of assembling steps is reduced as compared with the case of assembling a plurality of support members. In addition, the support portion 60 (the wall portions 61A and 61B) and the beam portions 65A and 65B formed as a single member will be referred to as a support portion 60A.

When the beam portions 65A and 65B are made of a light absorbing material, high-intensity light from the VCSEL groups 22A and 22B located at the ends of the light source 20 on the capacitor 70A and 70B side is prevented from going to the outside without being transmitted through the diffusion plate 30. In other words, the overhang of the diffusion plate 30 on the capacitor 70A and 70B side can be reduced as compared with the case where the beam portions 65A and 65B are not provided. In other words, the area of the diffusion plate 30 is reduced.

In addition, the beam portions 65A and 65B can prevent foreign substances such as dust or dirt from entering around the light source 20.

Third exemplary embodiment

In the light emitter 4B to which the third exemplary embodiment is applied, the support portion 60B is provided so as to surround the light source 20, the PD40, and the capacitors 70A and 70B.

Fig. 11A and 11B are plan views of a light emitter 4B to which the third exemplary embodiment is applied. Fig. 11A is a plan view, and fig. 11B is a sectional view taken along line XIB-XIB of fig. 11A. The same portions as those of the light emitter 4 illustrated in fig. 7A and 7B will be given the same reference numerals, and a description thereof will be omitted.

In the light emitter 4B, the light source 20, the PD40, and the capacitors 70A and 70B are covered with the diffusion plate 30. In addition, the support portion 60B includes wall portions 61A, 61B, 66A, and 66B, the wall portions 61A, 61B, 66A, and 66B supporting the diffusion plate 30 on four sides and being disposed so as to surround the light source 20, the PD40, and the capacitors 70A and 70B. In addition, the support portion 60B (the wall portions 61A, 61B, 66A, and 66B) is formed as a single member by integral molding or the like. The support portion 60B is made of a light absorbing material.

In this case, in the light source 20 of the light emitter 4B, the optical axis direction side is covered by the diffusion plate 30, and the side surface side is covered by the support portion 60. Since the support 60 is made of a light absorbing material, light emitted from the light source 20 is prevented from directly leaking to the outside. In addition, since the support portion 60B is formed as a single member, the number of assembly steps can be reduced as compared with the case where a plurality of support members are assembled.

Modification of light emitter 4B

In the light emitter 4B to which the third exemplary embodiment is applied, the diffusion plate 30 also covers the capacitors 70A and 70B. In general, the larger the area of the diffuser plate 30, the higher the price. In addition, it is not necessary for the diffusion plate 30 to cover the capacitors 70A and 70B. Here, in the light emitter 4B-1 as a modified example of the light emitter 4B, a blocking portion for blocking transmission of light is provided at a part of the upper side of the support portion 60B of the light emitter 4B illustrated in fig. 11A, and the area of the diffusion plate 30 is reduced.

Fig. 12A and 12B are views for illustrating a light emitter 4B-1, and the light emitter 4B-1 is a modification of the light emitter 4B to which the third exemplary embodiment is applied. Fig. 12A is a plan view, and fig. 12B is a sectional view taken along line XIIB-XIIB of fig. 12A. The same portions as those of the light emitter 4B illustrated in fig. 11A and 11B will be given the same reference numerals, and a description thereof will be omitted.

In the light emitter 4B-1, the diffusion plate 30 is provided only on the optical axis direction side of the light source 20, and the capacitors 70A and 70B are not covered with the diffusion plate 30 but are covered with the stoppers 67A and 67B. As illustrated in fig. 12A, the light emitter 4B-1 is provided with wall portions 61A, 61B, 66A, and 66B, similar to the support portion 60B of the light emitter 4B. In addition, the stoppers 67A and 67B are provided at a part of the upper opening of the support 60B (fig. 12A). The blocking portion 67A is on the wall portion 66A side so as not to block the light emitted from the light source 20 and transmitted through the diffusion plate 30, and is provided to cover the capacitor 70A. The blocking portion 67B is on the side of the wall portion 66B so as not to block light emitted from the light source 20 and transmitted through the diffusion plate 30, and is provided to cover the capacitor 70B.

In addition, the surfaces (+ z-direction side surfaces) of the stoppers 67A and 67B are formed as surfaces flush with the surfaces of the wall portions 61A, 61B, 66A, and 66B. In addition, a gap is provided between the rear surfaces (surfaces on the z direction side) of the barriers 67A and 67B and the capacitors 70A and 70B so as not to contact the capacitors 70A and 70B. In addition, the support portion 60B (the wall portions 61A, 61B, 66A, and 66B) and the stoppers 67A and 67B are formed as a single member by integral molding. The diffuser plate 30 is joined and fixed to the upper surfaces of the wall portions 61A and 61B and the ends of the surfaces of the stoppers 67A and 67B. In other words, the diffuser plate 30 is provided to seal the opening formed by the wall portions 61A and 61B and the stoppers 67A and 67B. In this way, the support portion 60B and the blocking portions 67A and 67B forming a single member are referred to as a support portion 60B-1.

Even in the light emitter 4B-1, in the light source 20, the optical axis direction side is covered by the diffusion plate 30, and the side surface side is covered by the support portion 60B-1. Since the support portion 60B-1 is made of a light absorbing material, light emitted from the light source 20 is prevented from directly leaking to the outside. In addition, the area of the diffusion plate 30 is smaller than that of the diffusion plate 30 of the light emitter 4B. Thus, the price of the optical device 3 remains low. In addition, since the support portion 60B-1 is formed as a single member, the number of assembly steps can be reduced as compared with the case where a plurality of support members are assembled.

Fourth exemplary embodiment

In the light emitters 4, 4-1, and 4-2 to which the first exemplary embodiment is applied, the light emitter 4A to which the second exemplary embodiment is applied, and the light emitters 4B and 4B-1 to which the third exemplary embodiment is applied, no wall portion, i.e., a support portion, is provided between the light source 20 and the capacitors 70A and 70B. The light emitter 4C to which the fourth exemplary embodiment is applied includes a support portion 60C, and the support portion 60C is provided with wall portions 68A and 68B between the light source 20 and the driving portion 50.

Fig. 13A and 13B are views for illustrating a light emitter 4C to which the fourth exemplary embodiment is applied. Fig. 13A is a plan view, and fig. 13B is a sectional view taken along line XIIIB-XIIIB of fig. 13A. The same portions as those of the light emitter 4 illustrated in fig. 7A and 7B will be given the same reference numerals, and a description thereof will be omitted.

The support portion 60C of the light emitter 4C includes wall portions 61A and 61B provided on both sides of the diffusion plate 30 and wall portions 68A and 68B on the remaining both sides. In addition, the wall portions 61A and 61B and the wall portions 68A and 68B are different in thickness from each other. Specifically, the thickness t of the wall portions 68A and 68B₂Is smaller than the thickness t of the wall portions 61A and 61B₁(t₁>t₂). The thick wall portions 61A and 61B mainly support the diffuser plate 30. In addition, the thickness of the wall portions 68A and 68B may be set to attenuate any influence on the inductance of the wiring connecting the light source 20 and the capacitors 70A and 70B to each other. When the wall portions 68A and 68B are provided, the light from the light source 20 is prevented from going to the outside without passing through the diffusion plate 30. In addition, since the light source 20 is surrounded by the support portion 60C and the diffusion plate 30, since foreign substances such as dust or dirt are prevented from entering around the light source 20.

The support portion 60C (the wall portions 61A, 61B, 68A, and 68B) is formed as a single member by integral molding. Therefore, the number of assembling steps is reduced as compared with the case of assembling a plurality of support members.

Fifth exemplary embodiment

The sectional structure of the information processing apparatus 1 using the light emitters 4, 4-1 to 4-2 to which the first exemplary embodiment is applied, the light emitter 4A to which the second exemplary embodiment is applied, the light emitters 4B and 4B-1 to which the third exemplary embodiment is applied, and the light emitter 4C to which the fourth exemplary embodiment is applied will be described. In addition, the information processing apparatus 1 is an example of a light emitting device.

Cross-sectional structure of information processing apparatus 1

Here, a cross-sectional structure of the information processing apparatus 1 when the information processing apparatus 1 uses the light emitter 4 to which the first exemplary embodiment is applied will be described. In addition, this will apply equally to the case where other light emitters are used.

Fig. 14 is a view for illustrating a sectional structure of the information processing apparatus 1 using the light emitter 4. Fig. 14 illustrates a cross section on the xz plane in fig. 7A.

The information processing apparatus 1 includes an optical device 3 and a housing 100. As described above, the optical device 3 includes the light emitter 4 and the 3D sensor 5. In other words, the housing 100 accommodates the light emitter 4. Here, the 3D sensor 5 is mounted on the substrate 10 provided in the light emitter 4, similarly to the light emitter 4 illustrated in fig. 7A and 7B.

The case 100 includes a transmissive part plate 110 and a transmissive part plate 120, and light emitted from the light source 20 included in the light emitter 4 is transmitted through the transmissive part plate 110, and light received by the 3D sensor 5 is transmitted through the transmissive part plate 120. The transmissive part plate 110 is disposed at a portion corresponding to an area where the light source 20 emits light, and the transmissive part plate 120 is disposed at a portion corresponding to an area where the 3D sensor 5 receives light. The case 100 is made of, for example, a metal material such as aluminum or magnesium or a resin material. In addition, the transmissive part plates 110 and 120 are composed of a transparent material such as glass or acrylic (acrylic).

The substrate 10 is held by the substrate holding device 101 so as to hold the substrate 10 with respect to the housing 100. In addition, on the 3D sensor 5, a lens 130 for condensing the light transmitted through the transmissive part plate 120 to the 3D sensor 5 is provided. The lens 130 is held by a lens holding device 131 so as to hold the lens 130 with respect to the substrate 10. The substrate holder 101 is, for example, a fastener such as a screw or a fitting member made of resin or the like.

In the information processing apparatus 1, the distance between the light source 20 of the light emitter 4 and the driving section 50 is set smaller than the distance between the light source 20 and the transmission section plate 110.

In addition, the transmissive part plate 120 may have a function of a lens 130.

After transmitting through the diffusion plate 30, the light emitted from the light source 20 of the light emitter 4 is transmitted through the transmissive part plate 110 and applied to the measurement target.

When the light emitter 4 (optical device 3) is accommodated in the housing 100 in this way, the diffusion plate 30 is prevented from being damaged. In other words, the high intensity light is prevented from being directly applied to the outside due to the damage of the diffusion plate 30.

In the first to fifth exemplary embodiments described above, the diffusion plate 30 that increases the spread angle of light emitted by the light emitting elements is described as an example of the cover. As an alternative to the diffusion plate 30, the cover may be a member through which light is transmitted, for example, a transparent base material such as a protective cover, an optical member such as a condensing lens and a microlens array having a condensing action to inversely reduce the spread angle, or the like. Here, a cover comprising a member is employed.