阅读说明：本技术 显示装置、非接触开关以及电子设备 (Display device, non-contact switch, and electronic apparatus ) 是由 田上靖宏 于 2020-03-05 设计创作，主要内容包括：本发明提供一种使纵向的视场角扩大的显示装置。显示装置在导光板(11)的背面(11b)具备使第一图像成像的第一光路变更部组(131)和使第二图像成像的第二光路变更部组(132),第一光路变更部组的倾斜角与第二光路变更部组的倾斜角之差为10°以上。(The invention provides a display device which enlarges the vertical field angle. The display device is provided with a first optical path changing unit group (131) for forming an image of a first image and a second optical path changing unit group (132) for forming an image of a second image on the back surface (11b) of a light guide plate (11), and the difference between the inclination angle of the first optical path changing unit group and the inclination angle of the second optical path changing unit group is 10 DEG or more.)

1. A display device is characterized by comprising:

a light source;

a light guide plate for guiding light incident from the light source, changing an optical path of the guided light, and emitting the light from the emission surface to spatially form a first image and a second image,

the light guide plate includes, on a back surface facing the emission surface: a first optical path changing unit group that forms the first image by changing an optical path of the light; a second optical path changing section group that images the second image by changing an optical path of the light,

the difference between the inclination angle of the reflection surface of the first optical path changing unit group with respect to the back surface for changing the optical path of the light and the inclination angle of the reflection surface of the second optical path changing unit group with respect to the back surface for changing the optical path of the light is 10 ° or more.

2. The display device of claim 1,

the first optical path changing unit group changes the inclination angle of the reflection surface of the optical path of the light with respect to the back surface to be less than 45 °, and the second optical path changing unit group changes the inclination angle of the reflection surface of the optical path of the light with respect to the back surface to be 45 ° or more.

3. The display device according to claim 1 or 2,

one of the first image and the second image is a three-dimensional image, and the other is a two-dimensional image.

4. The display device according to any one of claims 1 to 3,

the first image and the second image are imaged on different spaces from each other.

5. A non-contact switch is characterized by comprising:

a display device according to any one of claims 1 to 4;

and a sensor that detects the object at a detection point in space in a non-contact manner.

6. An electronic device, characterized in that,

a non-contact switch according to claim 5.

Technical Field

The present invention relates to a display device and the like that images an image in space.

Background

Patent document 1 discloses an optical device (display device) for forming a three-dimensional image. The optical apparatus includes: a light guide plate; and a light focusing unit that substantially focuses the light guided by the light guide plate on one converging point or converging line in space, or emits the light emitted in a direction substantially diverging from the one converging point or converging line in space from the exit surface.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-114929 (laid-open No. 6/23 2016) "

However, in the display device disclosed in patent document 1, there is a problem that a viewing angle in which a user can visually recognize a formed image is narrow in a direction parallel to a direction in which light is guided in the light guide plate (hereinafter, referred to as a vertical direction in the present specification).

For example, when the emission surface of the light guide plate is parallel to the vertical direction and the center direction of the angle of view is set to 30 ° with respect to the front surface of the display device, the angle of view of the image is in the range of 30 ° ± 20 °, that is, about 10 ° to 50 °. When the viewpoint deviates from the range, the user cannot visually recognize the image.

Disclosure of Invention

An object of one embodiment of the present invention is to realize a display device or the like that enlarges a viewing angle in a vertical direction.

In order to solve the above problem, a display device according to an aspect of the present invention includes: a light source; a light guide plate that guides light incident from the light source, changes an optical path of the guided light, and emits the light from an emission surface to spatially form a first image and a second image, the light guide plate including, on a back surface facing the emission surface: a first optical path changing unit group that forms the first image by changing an optical path of the light; and a second optical path changing unit group that changes an optical path of the light to form an image of the second image, wherein a difference between an inclination angle of a reflection surface of the first optical path changing unit group, which changes the optical path of the light, with respect to the back surface and an inclination angle of the reflection surface of the second optical path changing unit group, which changes the optical path of the light, with respect to the back surface is 10 ° or more.

ADVANTAGEOUS EFFECTS OF INVENTION

According to an aspect of the present invention, a display device or the like can be realized in which the vertical viewing angle is enlarged.

Drawings

Fig. 1 is a cross-sectional view of the optical path changing portions included in the first optical path changing portion group and the second optical path changing portion group on a plane perpendicular to the reflection surface.

Fig. 2 is a diagram showing an example of the structure of the display device of the present embodiment.

Fig. 3 is a diagram showing an example of an image formed by the display device of the present embodiment.

Fig. 4 is a diagram showing the appearance of a stereoscopic image and a planar image corresponding to the height of the viewpoint of the user.

Fig. 5 is a diagram showing a configuration of a non-contact switch according to the present embodiment.

Fig. 6(a) to (c) are diagrams showing a case where the non-contact switch of the present invention is applied to an input portion of an elevator.

Fig. 7 is a diagram showing a case where the non-contact switch of the present invention is applied to an input portion of a warm water washing toilet bowl.

Fig. 8(a) is a view showing the area of a region where the optical path changing portion is formed on the back surface of the light guide plate when the second optical path changing portion group forms an image of a fixed region in another stereoscopic image. (b) The second optical path changing unit group is a diagram showing the area of a region where the optical path changing unit is formed on the back surface of the light guide plate when the second optical path changing unit group forms an image of a fixed region in the planar image.

Fig. 9(a) is a view showing the area of a region where the optical path changing portion is formed on the rear surface of the light guide plate corresponding to a space where the stereoscopic image and another stereoscopic image are superimposed on each other when the stereoscopic image and the other stereoscopic image are formed in the space. (b) The drawing shows the area of a region where the optical path changing portion is formed on the back surface of the light guide plate corresponding to each of the spaces when the stereoscopic image and the other stereoscopic image are formed in the different spaces.

Fig. 10(a) is a diagram showing a structure of a modification of the light guide plate, and (b) is a cross-sectional view of a surface of the end face of the light guide shown in (a), the surface being parallel to a direction from the light source to the end face and perpendicular to the back face.

Fig. 11(a) is a diagram showing a configuration of a further modification of the light guide plate, and (b) is a cross-sectional view of a surface of an end face of the light guide plate shown in (a), the surface being parallel to a direction from the light source toward the end face and perpendicular to the rear face.

Fig. 12 is a perspective view of a display device according to a modification of the present embodiment.

Fig. 13 is a sectional view showing a structure of a display device according to a modification of the present embodiment.

Fig. 14 is a plan view showing a structure of a display device according to a modification of the present embodiment.

Fig. 15 is a perspective view showing a configuration of an optical path changing unit provided in a display device according to a modification of the present embodiment.

Fig. 16 is a perspective view showing an arrangement of the optical path changing unit.

Fig. 17 is a perspective view showing a method of imaging a stereoscopic image by a display device according to a modification of the present embodiment.

Fig. 18 is a diagram showing an example of an image formed by the display device, which is different from that of fig. 3.

Fig. 19 is a diagram showing an example of an image formed by the display device, which is different from that of fig. 18.

Detailed Description

An embodiment according to an aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described below with reference to the drawings.

1 example of application

The display device 10 of the present embodiment includes a light source 12 and a light guide plate 11. The light guide plate 11 guides light incident from the light source 12, changes the optical path of the guided light, and emits the light from the emission surface, thereby spatially forming a first image and a second image.

Fig. 2 is a diagram showing an example of the structure of the display device 10 according to the present embodiment. In fig. 2, a state in which the display device 10 displays a stereoscopic image I, more specifically, a case in which a button-shaped stereoscopic image I of "ON" characters is displayed is shown.

The light guide plate 11 has a rectangular parallelepiped shape, and is formed of a resin material having transparency and a relatively high refractive index. The material forming the light guide plate 11 may be, for example, polycarbonate resin, polymethyl methacrylate resin, glass, or the like. The light guide plate 11 includes: an emission surface 11a from which light is emitted, a back surface 11b on the opposite side of the emission surface 11a, end surfaces 11c, 11d, 11e, and 11f which are end surfaces on four sides. The end surface 11c is an incident surface on which light projected from the light source 12 is incident on the light guide plate 11. The end face 11d is a face opposite to the end face 11 c. The end face 11e is a face opposite to the end face 11 f. The light guide plate 11 guides light incident from the light source 12, and emits the light from the emission surface 11a to form an image in a space. The Light source 12 is, for example, an LED (Light Emitting Diode) Light source.

A plurality of optical path changing portions 13 including an optical path changing portion 13a, an optical path changing portion 13b, and an optical path changing portion 13c are formed on the back surface 11b of the light guide plate 11. The optical path changing portion 13a, the optical path changing portion 13b, and the optical path changing portion 13c are formed along the line La, the line Lb, and the line Lc, respectively. Here, the lines La, Lb, and Lc are straight lines substantially parallel to the Z-axis direction. The arbitrary optical path changing portion 13 is formed substantially continuously in the Z-axis direction. In other words, the plurality of optical path changing portions 13 are formed along predetermined lines in a plane parallel to the emission surface 11 a.

The light projected from the light source 12 and guided by the light guide plate 11 enters each position in the Z-axis direction of the optical path changing unit 13. The optical path changing unit 13 substantially converges the light incident on each position of the optical path changing unit 13 at a fixed point corresponding to each optical path changing unit 13. Fig. 3 shows, in particular, an optical path changing unit 13a, an optical path changing unit 13b, and an optical path changing unit 13c as a part of the optical path changing unit 13. Fig. 3 shows a case where the plurality of lights emitted from the optical path changing portion 13a, the optical path changing portion 13b, and the optical path changing portion 13c converge in the optical path changing portion 13a, the optical path changing portion 13b, and the optical path changing portion 13c, respectively.

Specifically, the optical path changing section 13a corresponds to the fixed point PA of the stereoscopic image I. The light from each position of the optical path changing section 13a is converged to the fixed point PA. Therefore, the wave surface of the light from the optical path changing unit 13a becomes the wave surface of the light emitted from the fixed point PA. The optical path changing unit 13b corresponds to the fixed point PB on the stereoscopic image I. The light from each position of the optical path changing unit 13b is converged to the fixed point PB. In this way, the light from each position of any of the optical path changing portions 13 is substantially converged at a fixed point corresponding to each of the optical path changing portions 13. Thus, the wave surface of the light emitted from the corresponding fixed point can be provided by the arbitrary optical path changing section 13. The fixed points corresponding to the optical path changing portions 13 are different from each other, and a stereoscopic image I recognized by the user is spatially formed (more specifically, spatially from the light guide plate 11 to the emission surface 11a side) by a set of a plurality of fixed points corresponding to the optical path changing portions 13.

2 example of construction

Fig. 3 is a diagram showing an example of an image formed by the display device 10 according to the present embodiment. In the example shown in fig. 3, the display device 10 images a button-shaped stereoscopic image IA (first image) and a planar image IB (second image) of the character string "DOWN". In this way, it is preferable that one of the images imaged by the display device 10 is a stereoscopic image (three-dimensional image) and the other is a planar image (two-dimensional image). In addition, in the display device 10, it is preferable that the stereoscopic image IA and the planar image IB are imaged on mutually different spaces. These reasons will be described later.

In the display device 10 of the present embodiment, the light guide plate 11 includes, as the light path changing unit 13, the first light path changing unit group 131 and the second light path changing unit group 132 on the back surface 11b facing the emission surface 11 a. The first optical path changing unit group 131 changes the optical path of the light from the light source 12 to form the stereoscopic image IA. The second optical path changing unit group 132 forms the planar image IB by changing the optical path of the light from the light source 12. The first optical path changing part group 131 and the second optical path changing part group 132 include a plurality of optical path changing parts, respectively.

Fig. 1 is a cross-sectional view of a surface perpendicular to the reflection surfaces 131a and 132a of the optical path changing portions included in the first optical path changing portion group 131 and the second optical path changing portion group 132. The reflecting surfaces 131a and 132a are surfaces of an optical path changing section that changes an optical path by reflecting incident light.

In the optical path changing section, the angle of the reflection surface 131a or 132a with respect to the back surface 11b is referred to as an inclination angle. As shown in fig. 1, the inclination angle of the optical path changing portions included in the first optical path changing portion group 131 (hereinafter, simply referred to as the inclination angle of the first optical path changing portion group 131) is θ 1. The inclination angle of the optical path changing units included in the second optical path changing unit group 132 (hereinafter, simply referred to as the inclination angle of the second optical path changing unit group 132) is θ 2. The inclination angle θ 1 is, for example, 40 °. The inclination angle θ 2 is, for example, 50 °.

A case where the light source 12 causes light to enter from vertically below the light guide plate 11 in a state where the emission surface 11a is parallel to the vertical direction is considered. In this case, the stereoscopic image IA formed by the first optical path changing unit group 131 is visually recognized in the vertical direction (vertical direction) within an angular range from the substantially front side to the upper side of the display device 10. On the other hand, the planar image IB imaged by the second optical path changing unit group 132 is visually recognized in the longitudinal direction within an angular range from substantially the front side to the lower side of the display device 10.

In addition, when the emission surface 11a is parallel to the horizontal plane, the image formed by the first optical path changing unit group 131 is visually recognized in an angle range from the substantially front surface of the display device 10 to the side opposite to the light source 12 in the vertical direction. On the other hand, the image imaged by the second optical path changing part group 132 is visually recognized in an angular range from the substantially front surface of the display device 10 to the light source 12 side in the longitudinal direction.

Fig. 4 is a diagram showing the appearance of the stereoscopic image IA and the planar image IB corresponding to the viewpoint height of the user. In the example shown in fig. 4, the display device 10 is provided on a vertical wall W.

In the example shown in fig. 4, when the viewpoint of the user is a viewpoint P1 having a height that is approximately the same as the height at which the display device 10 is provided (hereinafter, simply referred to as the height of the display device 10), the user can visually recognize both the stereoscopic image IA and the planar image IB. When the viewpoint of the user is the viewpoint P2 higher than the height of the display device 10, the user cannot visually recognize the planar image IB but can visually recognize the stereoscopic image IA. In contrast, in the case where the viewpoint of the user is the viewpoint P3 lower than the height of the display device 10, the user can visually recognize the plane image IB but cannot visually recognize the stereoscopic image IA.

As described above, in the display apparatus 10, the angular range in which the first optical path changing part group 131 images the stereoscopic image IA and the angular range in which the second optical path changing part group 132 images the planar image IB do not completely coincide with each other. Therefore, the angle of view at which at least one of the stereoscopic image IA formed by the first optical path changing unit group 131 and the planar image IB formed by the second optical path changing unit group 132 can be viewed is wider than that in the case where all the optical path changing units have the same inclination angle. Therefore, the angle of view of the display device 10 in the vertical direction can be enlarged. For example, in the case where the display apparatus 10 is provided on a wall, at least one of the stereoscopic image IA and the planar image IB can be seen by both a person with a high height and a person with a low height. In the same case, at least one of the stereoscopic image IA and the planar image IB can be visually recognized by both a standing person and a seated person (for example, a person using a wheelchair).

The inclination angles of the first optical path changing unit group 131 and the second optical path changing unit group 132 are not limited to the above examples.

The difference between the inclination angle θ 1 of the first optical path changing unit group 131 and the inclination angle θ 2 of the second optical path changing unit group 132 is preferably 10 ° or more. By having such a difference between the tilt angles θ 1 and θ 2, the angle of view at which at least one of the stereoscopic image IA and the planar image IB can be visually recognized can be significantly enlarged for the display device 10.

The inclination angle θ 1 of the first optical path changing unit group 131 is preferably smaller than 45 °, and the inclination angle θ 2 of the second optical path changing unit group 132 is preferably 45 ° or more. Further, the inclination angle θ 1 of the first optical path changing unit group 131 is more preferably smaller than 40 °, and the inclination angle θ 2 of the second optical path changing unit group 132 is more preferably 50 ° or more. In this case, the angle of view can be enlarged on both the light source 12 side and the opposite side to the light source 12 in the longitudinal direction with respect to the front surface of the display device 10.

In addition, a case where the light source 12 causes light to enter from above the light guide plate 11 in a state where the emission surface 11a is vertical to the horizontal plane may be considered. In this case, the range of the inclination angle θ 1 at which the first optical path changing part group 131 images an image on the upper side and the range of the inclination angle θ 2 at which the second optical path changing part group 132 images an image on the lower side are opposite to each other. That is, in this case, the inclination angle θ 1 is preferably 45 ° or more, and the inclination angle θ 2 is preferably less than 45 °.

The light guide plate 11 may further include a different optical path changing unit group from the first optical path changing unit group 131 and the second optical path changing unit group 132. When the light guide plate 11 includes three or more optical path changing unit groups, the difference in inclination angle may be 10 ° or more for any two optical path changing unit groups.

Example of 3 actions

Fig. 5 is a diagram showing the structure of the non-contact switch 1 according to the present embodiment. The non-contact switch 1 includes a display device 10 and a sensor 20. The display device 10 is as described above. For simplicity, fig. 5 shows only a stereoscopic image IC having a button shape different from the stereoscopic image IA as an image imaged by the display device 10.

The sensor 20 is a sensor that detects an object at a detection point in space in a non-contact manner. In the example shown in fig. 5, the sensor 20 is configured to use the vicinity of the upper surface of the button shape of the stereoscopic image IC as a detection point. When the user presses a button of the stereoscopic image IC by the finger F, the sensor 20 detects the finger F (object). Specific examples of the sensor 20 include an infrared sensor, a camera type sensor, a capacitance type sensor, a distance sensor, and the like.

Examples Of the distance sensor include a tof (time Of flight) sensor or a psd (position Sensitive detector) sensor. The TOF sensor obtains the distance to the object based on the time of flight (delay time) of light reflected by the object from the light source and reaching the light receiving portion of the sensor and the speed (3 × 108m/s) of the light. The PSD sensor is a sensor that detects the position of the center of gravity of the amount of light in the light spot.

As described above, the contactless switch 1 includes the display device 10. Therefore, the user can perform input based on the image imaged by the display device 10 whose field angle is wide.

The electronic device of the present embodiment includes a non-contact switch 1. The electronic device of the present embodiment will be described below.

Fig. 6(a) to (c) are diagrams showing a case where the contactless switch 1 of the present invention is applied to an input portion of an elevator. As shown in fig. 6(a), the contactless switch 1 can be applied to, for example, an input unit 200 (electronic device) of an elevator. Specifically, the input unit 200 displays stereoscopic images I1 to I12. The stereoscopic images I1 to I12 are displayed as images (stereoscopic images I1 to I10) to receive an input from a user who specifies a destination (floor number) of an elevator, or as images (stereoscopic images I11 and I12) to receive an instruction to open or close a door of an elevator. When receiving an input of any one of the stereoscopic images I from the user, the input unit 200 changes the imaging state of the stereoscopic image I (for example, changes the color of the stereoscopic image I), and outputs an instruction corresponding to the input to the control unit of the elevator. The display of the stereoscopic image I by the input unit 200 may be performed only when a person approaches the input unit 200. The input unit 200 may be disposed inside a wall of the elevator.

In the input unit 200 of the elevator, for example, in the case where there are many people in the elevator, a part of the body of the user is located at the imaging position of the stereoscopic image I, and there is a possibility that the input unit 200 receives an input unintended by the user. Then, the input unit 200 may accept the input of the user only when the rotation operation is accepted for the stereoscopic image I by the motion sensor, for example. In this case, the display device 10 displays an image prompting the user to perform a rotation operation, for example, as shown in fig. 6 (b). The rotation operation is an operation that is not normally performed unless the user intends, and therefore, the input unit 200 can be prevented from accepting an input that is not the user intention. As shown in fig. 6(c), the stereoscopic image I may be displayed in a recess provided in the inner wall of the elevator. Accordingly, the input of the stereoscopic image I is performed only when the instruction body F is inserted into the recess, and therefore the input unit 200 can be prevented from accepting an input which is not intended by the user.

Fig. 7 is a diagram showing a state in which the non-contact switch 1 of the present invention is applied to an input portion of a warm water washing toilet bowl. As shown in fig. 7, the non-contact switch 1 can be applied to, for example, an input portion 300 (operation panel portion) (electronic device) of a warm water washing toilet. Specifically, the input unit 300 displays stereoscopic images I1-I4. The stereoscopic images I1 to I4 are displayed as images to receive instructions to drive and stop the washing function of the warm water washing toilet. When the user accepts an input of any one of the stereoscopic images I, the input unit 300 changes the imaging state of the stereoscopic image I (for example, changes the color of the stereoscopic image I), and outputs an instruction corresponding to the input to the control unit of the warm water toilet bowl. There are many users whose direct contact with the operation panel of the warm water washing toilet bowl is not desired in terms of sanitation. In contrast, in the input unit 300, the user can operate the input unit 300 without directly touching (physically touching). Therefore, the user can perform the operation without taking sanitary consideration. The non-contact switch 1 may be applied to other devices which are not intended to be directly contacted in terms of hygiene. For example, the non-contact switch 1 is applied to a number issuing machine installed in a hospital, an operation portion of a moving door touched by an unspecified person, and the like. In addition, when there are a plurality of options such as surgery and internal medicine in a number issuing machine installed in a hospital, it is preferable that the stereoscopic image I corresponding to each option can be displayed. In addition, the non-contact switch 1 is suitable for a cash register or a coupon vending machine provided at a restaurant.

In addition, the contactless switch 1 can be applied to, for example, an input unit (electronic device) of an atm (automated teller machine), an input unit (electronic device) in a credit card reader, an input unit (electronic device) for unlocking a vault, an input unit (electronic device) of a door for unlocking by a password, and the like. Here, in the conventional password input device, input is performed by physically touching a finger to an input portion. In this case, the fingerprint or the temperature history is left in the input unit. Thus, it is possible to let others know the password. In contrast, when the non-contact switch 1 is used as an input unit, since the fingerprint and the temperature history do not remain, it is possible to prevent other people from knowing the password. As another example, the contactless switch 1 can be applied to a ticket vending machine installed at a station or the like.

Further, the non-contact switch 1 may be applied to electronic devices such as a lighting switch of a washing and dressing table, an operation switch of a faucet, an operation switch of a range hood, an operation switch of a dish washer, an operation switch of a refrigerator, an operation switch of a microwave oven, an operation switch of an IH cooking heater, an operation switch of an electrolytic water generating device, an operation switch of an intercom, a lighting switch of a corridor, or an operation switch of an audio system. By applying the contactless switch 1 to these switches, the following advantages are produced: (i) the switch is easy to clean because of no unevenness, (ii) the design is improved because a stereoscopic image can be displayed only when necessary, (iii) the switch is sanitary because contact with the switch is not required, and (iv) the movable part is not easily damaged because of disappearance.

In addition, particularly by applying the non-contact switch 1, the user can input based on an image imaged by the display device 10 having a wide angle of field. Therefore, the convenience of the electronic apparatus can be improved. In particular, in the case of an electronic device viewed by a plurality of users, it is effective to apply the non-contact switch 1 in terms of being able to cope with a height difference of a viewpoint due to a height, a posture, or the like of each user.

Modification 4

(4.1)

In the above example, the first optical path changing unit group 131 forms the stereoscopic image IA, and the second optical path changing unit group 132 forms the planar image IB. However, in the display device 10 of the present embodiment, the second optical path changing unit group 132 may image a stereoscopic image (second image) different from the stereoscopic image IA instead of the plane image IB.

However, when the first optical path changing unit group 131 forms the stereoscopic image IA, the second optical path changing unit group 132 forms the planar image IB, and the resolution (resolution) of the image is improved as compared with the case where another stereoscopic image is formed. The reason for this is as follows.

Fig. 8(a) is a diagram showing the area of the region where the optical path changing portion is formed on the back surface 11b of the light guide plate 11 when the second optical path changing portion group 132 forms an image of a fixed region in another stereoscopic image.

Fig. 8(b) is a diagram showing the area of a region where the optical path changing portion is formed on the back surface 11b of the light guide plate 11 when the second optical path changing portion group 132 forms an image of a fixed region in the planar image IB. In either of (a) and (b) of fig. 8, the first optical path changing part group 131 images the stereoscopic image IA.

In fig. 8(a) and (b), 1 block represents an area of 1 unit in the back surface 11 b. In the case of imaging a stereoscopic image, since the optical path changing unit needs to be provided for each of the right and left angles of view, the area of the region where the optical path changing unit is provided is larger than that in the case of imaging a planar image. In the example shown in fig. 8(a) and (b), in order to image a certain region in a stereoscopic image, a region of 8 units of area is required. On the other hand, in the example shown in fig. 8(b), in order to form a certain region in the planar image, a region of 1 unit area is required.

When the second optical path changing unit group 132 forms a stereoscopic image different from the stereoscopic image IA, the area of the region required for forming a fixed region is 16 units in each of the first optical path changing unit group 131 and the second optical path changing unit group 132, as shown in fig. 8 (a). On the other hand, when the second optical path changing unit group 132 forms the planar image IB, the area of the region required for forming the image of the fixed region is 9 units in each of the first optical path changing unit group 131 and the second optical path changing unit group 132, as shown in fig. 8 (b).

Therefore, when the first optical path changing unit group 131 forms the stereoscopic image IA, the area of the region where the optical path changing unit is formed, which is necessary to form a fixed region, is smaller in the case where the second optical path changing unit group 132 forms the planar image IB than in the case where the stereoscopic image is formed. Therefore, as described above, in the case where the second optical path changing part group 132 images the planar image IB, the resolution of the image imaged by the display device 10 is improved as compared with the case where the stereoscopic image is imaged.

(4.2)

In the above example, the stereoscopic image IA and the planar image IB are imaged on different spaces from each other. However, in the display device 10 of the present embodiment, the stereoscopic image IA and the planar image IB may be imaged on a space overlapping each other. Further, even in the case where the display device 10 images the stereoscopic image IA and another stereoscopic image, these stereoscopic images can be imaged on a space overlapping each other.

However, in the case where the stereoscopic image IA and the planar image IB or the stereoscopic image IA and another stereoscopic image are imaged on spaces different from each other, the resolution of the imaged image is improved as compared with the case where they are imaged on spaces overlapping each other. The reason for this is as follows.

Fig. 9(a) is a view showing the area of a region where the optical path changing portion is formed on the back surface 11b of the light guide plate 11 corresponding to a space where the stereoscopic image IA and another stereoscopic image are superimposed on each other when the stereoscopic image IA and the other stereoscopic image are formed in the space. Fig. 9 (b) is a view showing the area of a region where the optical path changing portion is formed on the back surface 11b of the light guide plate 11 corresponding to the space when the stereoscopic image IA and the other stereoscopic image are formed in the different spaces.

In fig. 9(a) and (b), 1 block represents an area of 1 unit, as in fig. 8(a) and (b). In fig. 9(a) and (b), in order to form a certain region in the stereoscopic image IA or another stereoscopic image, a region of 8 unit areas is necessary.

When the stereoscopic image IA and another stereoscopic image are formed in a space where they overlap with each other, it is necessary to provide 16 optical path changing portions per unit area in a region of the back surface 11b corresponding to the space, as shown in fig. 9 (a). In this way, when a plurality of images are formed in a space where the images overlap each other, the optical path changing unit for forming the plurality of images is provided in a region corresponding to the same space, and therefore, the area of the region where the optical path changing unit for forming each image is formed can be reduced. As a result, when a plurality of images are formed in a space where the images overlap with each other, the resolution of the images is reduced.

On the other hand, when the stereoscopic image IA and the other stereoscopic image are formed in different spaces, as shown in fig. 9 (b), the first optical path changing unit group 131 may be provided in an area of the rear surface 11b corresponding to the space in which the stereoscopic image IA is formed, in an area of 8 units. Similarly, the second optical path changing unit group 132 may be provided in an area of the rear surface 11b corresponding to a space where another stereoscopic image different from the stereoscopic image IA is imaged, the area being 8 units. In this way, when a plurality of images are formed in mutually different spaces, only the optical path changing unit for forming each image may be provided in the region corresponding to each space. Therefore, in the case where a plurality of images are imaged on mutually different spaces, the resolution of the images can be improved. In fig. 9(a) and (b), the case where the second optical path changing unit group 132 images another stereoscopic image is described, but the same can be said even in the case where the second optical path changing unit group 132 images a planar image IB.

(4.3)

Fig. 10(a) is a diagram showing a structure of a modification of the light guide plate 11. Fig. 10 (b) is a cross-sectional view of the end face 11f of the light guide plate 11 shown in fig. 10(a), the cross-sectional view being parallel to the direction from the light source 12 to the end face 11f and perpendicular to the rear face 11 b. The end surface 11f of the light guide plate 11 of the present modification has a sawtooth shape. More specifically, as shown in fig. 10(a) and (b), the end surface 11f of the light guide plate 11 of the present modification has a shape in which a plane perpendicular to the light source 12 and a plane parallel thereto are alternately repeated. The same applies to the end face 11 e.

In the light guide plate 11 of the present modification, most of the light emitted from the light source 12 and incident on the end surfaces 11e and 11f is incident on a surface perpendicular to the light source 12 and directly emitted to the outside of the light guide plate 11. Therefore, according to the light guide plate 11 of the present modification, stray light can be reduced. The stray light is emitted from the light source 12, reaches the end surfaces 11e and 11f, is reflected by the end surfaces 11e and 11f, and is further guided in the light guide plate 11.

(4.4)

Fig. 11(a) is a diagram showing a structure of another modification of the light guide plate 11. Fig. 11 (b) is a cross-sectional view of the end face 11f of the light guide plate 11 shown in fig. 11(a), the cross-sectional view being parallel to the direction from the light source 12 to the end face 11f and perpendicular to the rear face 11 b. The end surface 11f of the light guide plate 11 of the present modification has a sawtooth shape similarly to the end surfaces 11e and 11f shown in fig. 10. The same applies to the end face 11 e.

Further, the end portion of the end surface 11f of the light guide plate 11 of the present modification on the side of the light source 12 on which light is incident has a tapered shape that is closer to the light source 12 than the end portion on the side of the back surface 11 b. At this time, the end surface 11f has a taper angle θ 3 between the surface on which light from the light source 12 is incident and the back surface 11b of the light guide plate 11. The taper angle θ 3 is preferably 45 ° or less. The surfaces of the end faces 11d and 11e on which light from the light source 12 is incident have the same tapered shape.

In this case, a part of the light incident on the surface having the tapered shape is emitted to the outside of the light guide plate 11, and the remaining part is reflected toward the rear surface 11 b. Most of the light reflected toward the rear surface 11b is emitted from the rear surface 11b to the outside of the light guide plate 11, and only a very small portion of the light is reflected by the rear surface 11 b. The light reflected by the back surface 11b enters the tapered surface again, and a part of the light is emitted to the outside of the light guide plate 11. Only the light reflected again by the surface having the tapered shape becomes stray light. Therefore, in the light guide plate 11 of the present modification, stray light can be further reduced as compared with the light guide plate 11 shown in fig. 10(a) and (b). In the light guide plate 11 of the present modification, the end surfaces 11d, 11e, and 11f may have a tapered shape in which the end portion on the rear surface 11b side is closer to the light source 12 than the end portion on the emission surface 11a side.

(4.5)

A display device 10A according to a modification of the display device 10 will be described below.

Fig. 12 is a perspective view of the display device 10A. Fig. 13 is a sectional view showing the structure of the display device 10A. Fig. 14 is a plan view showing the structure of the display device 10A. Fig. 15 is a perspective view showing the configuration of the optical path changing unit 16 provided in the display device 10A.

As shown in fig. 12 and 13, the display device 10A includes a light source 12 and a light guide plate 15 (first light guide plate).

The light guide plate 15 is a member that guides light (incident light) incident from the light source 12. The light guide plate 15 is formed of a transparent resin material having a relatively high refractive index. As a material for forming the light guide plate 15, for example, polycarbonate resin, polymethyl methacrylate resin, or the like can be used. In this modification, the light guide plate 15 is formed of a polymethyl methacrylate resin. As shown in fig. 13, the light guide plate 15 includes an exit surface 15a (light exit surface), a back surface 15b, and an incident surface 15 c.

The emission surface 15a is a surface that emits light guided inside the light guide plate 15 and having its optical path changed by an optical path changing unit 16 described later. The emission surface 15a constitutes the front surface of the light guide plate 15. The back surface 15b is a surface parallel to the emission surface 15a, and is a surface on which a light path changing unit 16 described later is disposed. The incident surface 15c is a surface on which light emitted from the light source 12 is incident into the light guide plate 15.

The light emitted from the light source 12 and incident on the light guide plate 15 from the incident surface 15c is totally reflected by the emitting surface 15a or the back surface 15b, and is guided (guided) in the light guide plate 15.

As shown in fig. 13, the optical path changing unit 16 is formed on the rear surface 15b inside the light guide plate 15, and is a member for changing the optical path of the light guided in the light guide plate 15 and emitting the light from the emitting surface 15 a. The light guide plate 15 has a plurality of optical path changing portions 16 on a rear surface 15b thereof.

As shown in fig. 14, the optical path changing unit 16 is provided along a direction parallel to the incident surface 15 c. As shown in fig. 15, the optical path changing section 16 has a triangular cone shape and includes a reflection surface 16a that reflects (totally reflects) incident light. Like the optical path changing unit 13 described above, the optical path changing unit 16 includes a plurality of different optical path changing unit groups in which the inclination angles of the reflecting surfaces 16a differ from each other by 10 ° or more. The optical path changing unit 16 may be a recess formed on the rear surface 15b of the light guide plate 15, for example. The optical path changing unit 16 is not limited to the triangular pyramid shape. As shown in fig. 14, a plurality of optical path changing unit groups 17a, 17b, and 17c … … including a plurality of optical path changing units 16 are formed on the rear surface 15b of the light guide plate 15.

Fig. 16 is a perspective view showing the arrangement of the optical path changing unit 16. As shown in fig. 16, in each of the optical path changing unit groups 17a, 17b, and 17c … …, the reflection surfaces 16a of the plurality of optical path changing units 16 are arranged on the back surface 15b of the light guide plate 15 so that angles with respect to the incident direction of light are different from each other. Thus, the optical path changing unit groups 17a, 17b, and 17c … … change the optical path of the incident light and emit the incident light from the emission surface 15a in various directions.

Next, an imaging method of the stereoscopic image I using the display device 10A will be described with reference to fig. 17. Here, a case will be described in which a stereoscopic image I as a surface image is formed on a stereoscopic image forming surface P which is a surface perpendicular to the emission surface 15a of the light guide plate 15 by light whose optical path is changed by the optical path changing unit 16.

Fig. 17 is a perspective view showing an imaging method of a stereoscopic image I by the display device 10A. Here, a case will be described where a ring mark including oblique lines as the stereoscopic image I is formed on the stereoscopic image imaging plane P.

In the display device 10A, as shown in fig. 17, for example, the light whose optical path has been changed by each optical path changing unit 16 of the optical path changing unit group 17a intersects the stereoscopic image imaging plane P at a line La1 and a line La 2. Thereby, the line image LI as a part of the stereoscopic image I is imaged on the stereoscopic image imaging plane P. The line image LI is a line image parallel to the YZ plane. In this way, the line image LI of the line La1 and the line La2 is imaged by the light from the plurality of optical path changing sections 16 belonging to the optical path changing section group 17 a. The light of the images formed on the line La1 and the line La2 may be provided by at least 2 optical path changing units 16 in the optical path changing unit group 17 a.

Similarly, the light whose optical path is changed by each optical path changing portion 16 of the optical path changing portion group 17b intersects the stereoscopic image imaging plane P at the line Lb1, the line Lb2, and the line Lb 3. Thereby, the line image LI as a part of the stereoscopic image I is imaged on the stereoscopic image imaging plane P.

The light whose optical path is changed by each optical path changing unit 16 of the optical path changing unit group 17c intersects the stereoscopic image imaging plane P at the line Lc1 and the line Lc 2. Thereby, the line image LI as a part of the stereoscopic image I is imaged on the stereoscopic image imaging plane P.

The positions in the X-axis direction of the line images LI formed by the optical path changing unit groups 17a, 17b, and 17c … … are different from each other. In the display device 10A, the distance in the X-axis direction of the line image LI imaged by each of the optical path changing unit groups 17a, 17b, and 17c … … can be reduced by reducing the distance between the optical path changing unit groups 17a, 17b, and 17c … …. As a result, in the display device 10A, the stereoscopic image I as a plane image is substantially formed on the stereoscopic image forming plane P by integrating the plurality of line images LI formed by the light whose optical path is changed by the optical path changing units 16 of the optical path changing unit groups 17a, 17b, and 17c … ….

The stereoscopic image imaging plane P may be a plane perpendicular to the X axis, a plane perpendicular to the Y axis, or a plane perpendicular to the Z axis. The stereoscopic image imaging plane P may be a plane that is not perpendicular to the X axis, the Y axis, or the Z axis. Further, the stereoscopic image imaging plane P may not be a plane but a curved plane. That is, the display device 10A can form the stereoscopic image I on any spatially arbitrary surface (plane and curved surface) by the optical path changing unit 16. In addition, by combining a plurality of plane images, a three-dimensional image can be imaged.

(4.6)

Fig. 18 is a diagram showing an example of an image formed by the display device 10, which is different from fig. 3. In the example shown in fig. 18, the display device 10 also images the stereoscopic image IA and the planar image IB. However, in the example shown in fig. 18, the imaging positions of the stereoscopic image IA and the planar image IB are different from the example shown in fig. 3.

In the example shown in fig. 3, the display device 10 images the planar image IB in a space different from the light guide plate 11. On the other hand, as shown in fig. 18, the display device 10 may form a planar image IB on the emission surface 11a of the light guide plate 11. Such a modification is also included in the present invention.

(4.7)

Fig. 19 is a diagram showing an example of an image formed by the display device 10, which is different from fig. 18. In the present modification, the display device 10 forms a planar image ID by guiding light from the light source 12 through the light guide plate 11, changing the optical path, and emitting the changed light. In fig. 19, an example of imaging of the plane image ID is shown by reference numeral 1901 as the plane image IB in fig. 3. Note that an example different from the plane image IB is denoted by reference numeral 1902.

In the above configuration example, as indicated by reference numeral 1901, the display device 10 forms the planar image ID on the outside of the light guide plate 11 in the same manner as the planar image IB shown in fig. 3 and the like. On the other hand, in the present modification, as shown by reference numeral 1902, the display device 10 forms a planar image ID on the back surface 11b of the light guide plate 11, that is, on the surface on which the optical path changing portion 13 is formed, and such a modification is also included in the present invention.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present invention.

(conclusion)

As described above, the display device according to one embodiment of the present invention includes a light source; a light guide plate that guides light incident from the light source, changes an optical path of the guided light, and emits the light from an emission surface to spatially form a first image and a second image, the light guide plate including, on a back surface facing the emission surface: a first optical path changing unit group that forms the first image by changing an optical path of the light; and a second optical path changing unit group that changes an optical path of the light to form an image of the second image, wherein a difference between an inclination angle of a reflection surface of the first optical path changing unit group, which changes the optical path of the light, with respect to the back surface and an inclination angle of the reflection surface of the second optical path changing unit group, which changes the optical path of the light, with respect to the back surface is 10 ° or more.

According to the above configuration, in the display device, the first optical path changing unit group and the second optical path changing unit group do not completely match each other in the direction in which light is incident from the light source to the light guide plate. Therefore, the display device can provide a display device in which the angle of view at which at least one of the first image and the second image can be visually recognized is enlarged.

In the display device according to the first aspect of the present invention, an inclination angle of the reflection surface that changes the optical path of the light with respect to the rear surface is less than 45 °, and an inclination angle of the reflection surface that changes the optical path of the light with respect to the rear surface is 45 ° or more.

According to the above configuration, it is possible to provide a display device in which the angle of view is enlarged on both the light source side and the opposite side to the light source in the direction in which light enters the light guide plate from the light source with respect to the front surface of the display device.

In the display device according to the first aspect of the present invention, one of the first image and the second image is a three-dimensional image, and the other is a two-dimensional image.

According to the above configuration, the area of the second optical path changing unit group can be reduced. Therefore, the resolution of the first image and the second image can be improved.

In the display device according to the first aspect of the present invention, the first image and the second image are formed in different spaces from each other.

According to the above configuration, the resolution of the first image and the second image can be improved.

Further, a non-contact switch according to an aspect of the present invention includes: the display device of any of the above embodiments; and a sensor that detects the object in a non-contact manner at a detection point in space.

According to the above configuration, the user can input based on the image imaged by the display device having a wide angle of field.

An electronic device according to an aspect of the present invention includes the above-described non-contact switch.

According to the above configuration, the user can operate the electronic device through the non-contact switch with improved convenience. Therefore, an electronic apparatus with improved convenience can be provided.

Description of the symbols

1: non-contact switch

10. 10A: display device

11. 15: light guide plate

11a, 15 a: emitting surface

11b, 15 b: back side of the panel

12: light source

131: first light path changing unit group

132: second optical path changing unit group

131a, 132a, 16 a: reflecting surface

20: sensor with a sensor element

200. 300, and (2) 300: input part (electronic equipment)