阅读说明：本技术 一种光斑大小及定焦位置可调节的光电传感器及调节方法 (Photoelectric sensor with adjustable light spot size and fixed focus position and adjusting method ) 是由 许永童 许用疆 谢勇 祁伟光 马路明 于 2019-09-19 设计创作，主要内容包括：本发明公开了一种光斑大小及定焦位置可调节的光电传感器及调节方法,其技术方案要点是：一种光斑大小及定焦位置可调节的光电传感器及调节方法,包括呈固定设置光源、聚光透镜,固定于光源与聚光透镜之间的平板调节补偿模块、平板厚度调节轴、固定连接于平板厚度调节轴的平板调节模块,平板调节模块与平板调节补偿模块相背离的端面呈平行且垂直于光源与聚光透镜所在直线,平板调节模块与平板调节补偿模块相向的端面相互平行且呈螺旋状设置,且平板调节模块朝向平板调节补偿模块的端面螺旋圈数小于或等于一圈。本发明通过透光介质的厚度可随意调整,成像位置可以调整到任意位置,调节光斑大小及定焦位置。(The invention discloses a photoelectric sensor with adjustable spot size and fixed focus position and an adjusting method, and the technical scheme is as follows: the utility model provides a photoelectric sensor and adjustment method that facula size and fixed focus position are adjustable, including being the fixed light source that sets up, condensing lens, the dull and stereotyped regulation compensation module who is fixed in between light source and the condensing lens, dull and stereotyped thickness regulating shaft, the dull and stereotyped regulation module of fixed connection in dull and stereotyped thickness regulating shaft, the terminal surface that dull and stereotyped regulation module deviates from mutually is parallel and perpendicular to light source and condensing lens place straight line, dull and stereotyped regulation module is parallel to each other with dull and stereotyped regulation compensation module terminal surface in opposite directions and is the heliciform setting, and dull and stereotyped regulation module is less than or equal to the round towards dull and stereotyped regulation compensation module. The invention can be adjusted at will through the thickness of the light-transmitting medium, the imaging position can be adjusted to any position, adjust the size of the facula and the fixed focus position.)

1. The utility model provides a light spot size and photoelectric sensor with adjustable prime position, is including being fixed light source (1), collector lens (4) of setting up, its characterized in that: the light source device is characterized by further comprising a flat plate adjusting compensation module (2) fixed between the light source (1) and the condensing lens (4), a flat plate thickness adjusting shaft (5) in rotating arrangement, and a flat plate adjusting module (3) fixedly connected to the flat plate thickness adjusting shaft (5), wherein the rotating axial direction of the flat plate thickness adjusting shaft (5) is parallel to the straight line where the light source (1) and the condensing lens (4) are located, the end faces of the flat plate adjusting compensation module (3) and the flat plate adjusting compensation module (2) deviate from each other are parallel and perpendicular to the straight line where the light source (1) and the condensing lens (4) are located, the opposite end faces of the flat plate adjusting compensation module (3) and the flat plate adjusting compensation module (2) are parallel to each other and are in spiral arrangement, and the number of spiral turns of the end faces of the flat plate adjusting compensation module (3) towards the flat plate adjusting, light generated by the light source (1) penetrates through the flat plate adjusting module (3) and the flat plate adjusting compensation module (2) and then enters the condensing lens (4).

2. The photosensor according to claim 1, wherein: and antireflection films are plated on two end faces of the flat plate adjusting module (3) and the flat plate adjusting compensation module (2).

3. The photosensor according to claim 1, wherein: the screw pitch of the end face, opposite to the flat plate adjusting compensation module (2), of the flat plate adjusting module (3) is 4.05 mm.

4. The photosensor according to claim 3, wherein: dull and stereotyped regulation compensation module (2) are fan-shaped setting, just dull and stereotyped regulation compensation module (2) fan-shaped opening angle is 60, dull and stereotyped regulation compensation module (2) external diameter is 10mm, the narrowest edge rear end between dull and stereotyped regulation compensation module (2) both ends face is 0.33 mm.

5. A method for adjusting a photoelectric sensor with adjustable light spot size and fixed focus position is characterized by comprising the following steps: a transparent medium is arranged between the light source (1) and the condensing lens (4), and the offset of the equivalent light source can be obtained by setting the thickness and the refractive index of the parallel light-transmitting plate to be n: a beam of light from a light source (1) having an incident angle a is emitted from the light source (1) and enters a parallel light-transmitting plate having a refractive index n from air, and a refraction angle i has

sina＝nsini

After propagating for a certain distance in the parallel light-transmitting plate, the light is emitted into the air, and then

S＝L/sini

＝L·sina/n

Wherein S is the propagation distance in the parallel light-transmitting plate, and L is the thickness of the parallel light-transmitting plate;

according to i and a, the displacement of the equivalent light source relative to the actual light source (1) can be obtained, and in a triangle, according to the sine theorem:

the following can be obtained:

wherein D is the displacement of the equivalent light source relative to the actual light source;

by introducing a transparent medium in the light path to change the position of the light source (1) relative to the focusing lens, imaging the formula by the lens

Wherein l is the distance between the light source (1) and the condensing lens (4);

it can be known that, under the condition that the focal length f is not changed, when the distance D between the equivalent light source s 'and the lens is changed, the corresponding image distance l' is also changed;

the size of the image distance L' is adjusted by adjusting the thickness L of the transparent medium.

Technical Field

The invention relates to the field of photoelectric sensing, in particular to a photoelectric sensor with adjustable light spot size and fixed focus position and an adjusting method.

Background

Nowadays, as industrial automation is gradually implemented, sensors as automatic sensors are widely used, and due to diversification of user requirements, the sensors need to be continuously created to meet different application scenarios.

In industrial automation, there is a type of detection that requires a small spot size for non-contact detection, such as detecting the presence or absence of an object through a small-sized optical aperture, detecting the small size of an object to be detected, and the like, and a suitable photoelectric sensor is required for such an application.

The spot size of the existing photoelectric sensor is mostly fixed. When detection targets of different sizes are encountered, the existing solutions are generally to redesign the sensor light source 1: and replacing the transmitting tube or the focusing lens, and leading in mass production after the customer passes the verification.

A few sensors can add transparent media with different thicknesses into an optical path, the thickness of the media is fixed, and the size of a light spot is changed by changing the thickness of the media.

In general, the range and measurement resolution of laser triangulation products are not adjustable. Moreover, since the position of the laser imaging spot is nonlinear with the displacement of the object, the resolution is also nonlinear with the displacement. In the selection process of the user, the situation that the measuring range and the resolution cannot meet the requirements often occurs.

When the light source is redesigned, the enterprise needs to invest manpower and material resources again, and the technical income of the enterprise is not great. The redesigned scheme needs to be delivered to the user for verification and then put into mass production, and the overall efficiency is greatly reduced.

A few sensors will add transparent media with different thicknesses into the optical path, but since the thicknesses of the media are fixed, the effect of changing the size of the light spot by changing the thickness of the media is limited, and users can only balance the existing effects.

Therefore, there is a need for an improved structure that overcomes the above-mentioned deficiencies.

Disclosure of Invention

The invention aims to provide a photoelectric sensor with adjustable light spot size and fixed focus position and an adjusting method.

The technical purpose of the invention is realized by the following technical scheme: a photoelectric sensor with adjustable light spot size and fixed focus position comprises a light source, a condensing lens, a flat plate adjusting and compensating module fixed between the light source and the condensing lens, a flat plate thickness adjusting shaft arranged in a rotating way, and a flat plate adjusting module fixedly connected with the flat plate thickness adjusting shaft, the rotating axial direction of the flat plate thickness adjusting shaft is parallel to the straight line where the light source and the condensing lens are positioned, the end surface of the flat plate adjusting module, which deviates from the flat plate adjusting compensation module, is parallel to and perpendicular to the straight line where the light source and the condensing lens are positioned, the opposite end surfaces of the flat plate adjusting module and the flat plate adjusting compensation module are parallel to each other and are arranged spirally, and the spiral turns of the end surface of the flat plate adjusting module facing the flat plate adjusting compensation module are less than or equal to one turn, and light generated by the light source penetrates through the flat plate adjusting module and the flat plate adjusting compensation module and then enters the condensing lens.

The invention is further provided with: and antireflection films are plated on two end faces of the flat plate adjusting module and the flat plate adjusting compensation module.

The invention is further provided with: the screw pitch of the end face, opposite to the flat plate adjusting compensation module, of the flat plate adjusting module is 4.05 mm.

The invention is further provided with: dull and stereotyped regulation compensation module is fan-shaped setting, just dull and stereotyped regulation compensation module's fan-shaped opening angle is 60, dull and stereotyped regulation compensation module external diameter is 10mm, the narrowest edge rear end between dull and stereotyped regulation compensation module both ends face is 0.33 mm.

The invention is further provided with: a method for adjusting a photoelectric sensor with adjustable light spot size and fixed focus position is characterized in that a transparent medium is arranged between a light source and a condensing lens, and the offset of an equivalent light source can be obtained by setting the thickness and the refractive index of a parallel light-transmitting plate to be n: a light beam of the light source with an incident angle a is emitted from the light source and enters a parallel light-transmitting plate with a refractive index n from air, and the refraction angle i is larger than the refraction angle

sina＝nsini

After propagating for a certain distance in the parallel light-transmitting plate, the light is emitted into the air, and then

S＝L/sini

＝L·sina/n

Wherein S is the propagation distance in the parallel light-transmitting plate, and L is the thickness of the parallel light-transmitting plate;

according to i and a, the displacement of the equivalent light source relative to the actual light source can be obtained, and in a triangle, according to the sine theorem:

the following can be obtained:

wherein D is the displacement of the equivalent light source relative to the actual light source;

by introducing a transparent medium in the optical path to change the position of the light source relative to the focusing lens, the formula is imaged by the lens

Wherein l is the distance between the light source and the condenser lens;

it can be known that, under the condition that the focal length f is not changed, when the distance D between the equivalent light source s 'and the lens is changed, the corresponding image distance l' is also changed;

the size of the image distance L' is adjusted by adjusting the thickness L of the transparent medium.

In conclusion, the invention has the following beneficial effects:

1) when the device is used, the light source generates light rays, the light rays sequentially penetrate through the flat plate adjusting compensation module and the flat plate adjusting module and then penetrate into the condensing lens, and the adjusting compensation module and the flat plate adjusting module can be equivalent to a transparent medium due to the fact that the opposite end faces of the adjusting compensation module and the flat plate adjusting module are parallel, so that the imaging position of the light source is changed;

2) after the flat plate thickness adjusting shaft is rotated, the flat plate adjusting module is rotated by a certain angle, the distance between two ends of the light ray passing through the flat plate adjusting module is correspondingly changed, namely the thickness of a transparent medium between the light source and the condensing lens is adjusted, the thickness of the transparent medium can be adjusted at will, the imaging position can be adjusted to any position, and the imaging size can be adjusted within a certain range; thereby achieving the purpose of adjusting the spot size of the photoelectric sensor, namely the fixed focus position;

3) the invention can be applied to the field of photoelectric sensing detection with requirements on the size of the light spot and the imaging position, and can expand the capability boundary of the photoelectric sensor.

Drawings

FIG. 1 is a first schematic structural diagram of embodiment 1;

FIG. 2 is a second schematic structural view of embodiment 1;

FIG. 3 is a schematic view of an equivalent light source of the principle part in example 2;

FIG. 4 is a schematic diagram of application example 1;

fig. 5 is a schematic diagram of application example 2.

The corresponding part names indicated by the numbers in the figures: 1. a light source; 2. a flat plate adjustment compensation module; 3. a plate adjustment module; 4. a condenser lens; 5. a plate thickness adjusting shaft.

Detailed Description

In order to make the technical means, the original characteristics, the achieved purposes and the effects of the invention easy to understand, the invention is further described with reference to the figures and the specific embodiments.