Reflection type photoelectric sensor with high visible light resolution and adjustable light spot size

Abstract

The invention relates to the technical field of photoelectric sensors, in particular to a reflection type photoelectric sensor with high visible light resolution and adjustable light spot size. The invention discloses a reflection-type photoelectric sensor with high visible light resolution and adjustable light spot size, which comprises a shell, and further comprises an emission lens for emitting light beams; the emission lens is arranged in the shell; the receiving lens is used for receiving the reflected light beams; the light spot adjusting mechanism is used for driving the transmitting lens to move so as to change the size of the light spot; and the detection distance adjusting mechanism is used for driving the receiving lens to move. According to the reflection type photoelectric sensor with the high visible light resolution and the adjustable light spot size, the receiving lens is driven to move up and down through the detection distance adjusting mechanism, the front-back position of the transmitting lens is adjusted through the transmitting lens light spot adjusting mechanism by applying gear adjustment, and therefore the size of the light spot is adjusted.

Description

Technical Field

[0001] The present application relates to the technical field of photoelectric sensors, and in particular to a reflective photoelectric sensor with high visible light resolution and adjustable spot size. Background Art

[0002] With the rapid development of automation technology, reflective photoelectric sensors have been widely used in industrial automation, robotics, intelligent monitoring, safety detection and other fields. The working principle of this type of sensor is to send out a beam of light from the transmitter. When the beam hits the object to be measured, it will be reflected back to the receiver. The internal circuit algorithm of the receiver will determine whether there is an object based on the received light signal.

[0003] The reflective photoelectric sensors currently on the market can make logical judgments based on the received light signals and output electrical signals for use by subsequent equipment; the miniaturization, low-power design, and application of digital and intelligent technologies of reflective photoelectric sensors enable them to operate stably in more complex environments.

[0004] However, the current reflective photoelectric sensors have the following technical problems: 1. Limited detection distance Most existing reflective photoelectric sensors can only detect within a specific distance range. Beyond this range, the performance of the sensor may degrade or even fail to work properly. To address the problem of limited detection distance, some manufacturers increase the complexity of the circuit inside the sensor to achieve long-distance detection, but this increases the power consumption and cost of the device.

[0005] 2. The spot size cannot be adjusted The size of the light spot formed by the sensor is fixed. For some objects of special shapes or areas that need to be accurately detected, a fixed-size light spot may not meet the detection requirements. As for the problem that the light spot size cannot be adjusted, some attempts have been made to indirectly adjust the light spot size by changing the structural design of the transmitting end, but this method has limited effect and is difficult to meet the detection requirements in different scenarios.

[0006] 3. Insufficient adjustment accuracy and anti-vibration performance Existing sensor adjustment mechanisms mostly use threaded transmission, and the adjustment accuracy is limited by the pitch processing accuracy. At the same time, the threaded matching method is prone to loosening in a vibration environment, affecting the stability and reliability of the sensor. In order to solve the problem of insufficient adjustment accuracy and anti-vibration performance, the traditional threaded transmission method is simple and easy to use, but it cannot meet the requirements of high precision and high stability. Summary of the invention

[0007] In order to overcome the shortcomings of the prior art, the present invention provides a reflective photoelectric sensor with high visible light resolution and adjustable spot size. The receiving lens is driven to move up and down by a detection distance adjustment mechanism, and the front and rear positions of the transmitting lens are adjusted by gear adjustment through the transmitting lens spot adjustment mechanism, thereby adjusting the size of the light spot. Therefore, the reflective photoelectric sensor described in this application can freely switch between focused and diffuse light spots to meet the detection requirements of special objects.

[0008] The technical solution adopted by the present invention to solve its technical problem is: A reflective photoelectric sensor with high visible light resolution and adjustable spot size, comprising a housing, and further comprising: An emitting lens, used for emitting a light beam; the emitting lens is arranged in the housing; A receiving lens, used for receiving the reflected light beam; A light spot adjustment mechanism, used to drive the emission lens to move, thereby changing the light spot size; The detection distance adjustment mechanism is used to drive the receiving lens to move.

[0009] In one or more technical solutions, a slider is arranged on the emitting lens; the light spot adjustment mechanism includes a first gear and a first rack meshing with the first gear, and the first rack is arranged on the slider.

[0010] In one or more technical solutions, the detection distance adjustment mechanism includes a driven member and a worm driving the driven member, the driven member includes an inner ring turbine and an outer ring second gear, and the worm and the turbine are meshed; The receiving lens is provided with a second rack, and the second rack is meshed with a second gear.

[0011] In one or more technical solutions, the transmission ratio of the detection distance adjustment mechanism is 30, and the radius of the second gear is 1.5 mm.

[0012] In one or more technical solutions, the reflective photoelectric sensor also includes an upper bracket and a lower bracket, the upper bracket is installed on the upper part of the shell, and the lower bracket is installed on the lower part of the shell; the receiving lens is arranged on the upper bracket; and the transmitting lens is arranged on the lower bracket.

[0013] In one or more technical solutions, a light-emitting tube is arranged on the housing; a light-emitting aperture diaphragm is arranged between the light-emitting tube and the emitting lens; and the light-emitting tube obtains a suitable light spot through the diaphragm.

[0014] In one or more technical solutions, a second knob for driving the worm to move is also provided on the housing.

[0015] In one or more technical solutions, a binary receiver is also included, and the binary receiver is used to receive the optical signal.

[0016] In one or more technical solutions, a lens is also included, and the lens is arranged on the housing.

[0017] In one or more technical solutions, a first knob for driving the first gear to move is also provided on the housing.

[0018] The beneficial effects of the present invention are: The reflective photoelectric sensor described in the present application can adapt to detection requirements in more different scenarios by adjusting the detection distance and the size of the light spot, thereby improving the flexibility and applicability of the sensor.

[0019] The reflective photoelectric sensor described in the present application uses a worm gear transmission method that has self-locking properties and can prevent loosening caused by vibration, thereby enhancing the stability and reliability of the sensor.

[0020] The reflective photoelectric sensor described in the present application can adjust the detection distance and the size of the light spot by simply turning a knob, which reduces the difficulty and cost of adjusting the sensor. At the same time, the structure of the worm gear transmission is relatively simple and easy to process and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the cross-sectional structure of the reflective photoelectric sensor of the present invention Figure 2 It is a schematic diagram of the overall structure of the reflective photoelectric sensor of the present invention; Figure 3 For the present invention Figure 2 Schematic diagram of explosion decomposition; Figure 4 It is a structural schematic diagram of the light spot adjustment mechanism of the reflective photoelectric sensor of the present invention; Figure 5 It is a structural schematic diagram of the detection distance adjustment mechanism of the reflective photoelectric sensor of the present invention; Figure 6 A schematic diagram of the light spot adjustment of the reflective photoelectric sensor of the present invention; Figure 7 A schematic diagram of adjusting the detection distance of the reflective photoelectric sensor of the present invention; Description of reference numerals: 1. Housing; 2. Transmitting lens; 3. Receiving lens; 4. Light spot adjustment mechanism; 5. Detection distance adjustment mechanism; 7. Binary receiver; 8. Lens; 21. Light-emitting tube; 22. Light-emitting aperture diaphragm; 41. Slider; 42. First gear; 43. First rack; 44. First knob; 51. Second gear; 52. Worm; 53. Turbine; 54. Second knob; 55. Second rack; 61. Upper bracket; 62. Lower bracket. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0023] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the present invention. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the formation of a better connection structure by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the invention can be combined interchangeably without conflicting with each other.

[0024] like Figure 1-Figure 3 As shown, a reflective photoelectric sensor with high visible light resolution and adjustable spot size includes a housing 1 and also includes: An emitting lens 2, used for emitting a light beam; the emitting lens 2 is arranged in the housing 1; A receiving lens 3, used for receiving the reflected light beam; A light spot adjustment mechanism 4 is used to drive the emission lens 2 to move, thereby changing the light spot size; The detection distance adjustment mechanism 5 is used to drive the receiving lens 3 to move.

[0025] Specifically, the housing is used to protect the product and play a role in installation and fixing to prevent the internal core components from being damaged. The receiving lens is driven up and down by the detection distance adjustment mechanism, and the emission lens spot adjustment mechanism uses gear adjustment to adjust the front and rear position of the emission lens, thereby adjusting the size of the spot.

[0026] In one or more embodiments, the reflective photoelectric sensor also includes an upper bracket 61 and a lower bracket 62, wherein the upper bracket 61 is installed on the upper part of the shell 1, and the lower bracket 62 is installed on the lower part of the shell 1; the receiving lens 3 is arranged on the upper bracket 61; and the transmitting lens 2 is arranged on the lower bracket 62.

[0027] Specifically, the upper bracket is installed in the upper part of the shell through a card slot. There is a vertical mounting slot on the upper bracket. The receiving lens is installed in the mounting slot and can move up and down; the transmitting lens is installed in the 4 T-slots in the lower part of the shell and can move a certain distance in the front and back directions.

[0028] It can be understood that the receiving lens is an optical lens that focuses the received optical fiber onto the sensing element (binary receiver) of the main board.

[0029] The emitting lens is an optical lens, a collimating lens, which refracts the light emitted by the light-emitting LED into parallel light.

[0030] In one or more embodiments, Figure 4 As shown, a slider 41 is disposed on the emitting lens 2 ; the light spot adjustment mechanism 4 includes a first gear 42 and a first rack 43 meshing with the first gear 42 , and the first rack 43 is disposed on the slider 41 .

[0031] Specifically, the emitting lens is fixedly mounted on the slider, and the slider is mounted in a corresponding mounting groove on the outer shell (a sliding groove corresponding to the slider is arranged in the mounting groove), and a first rack is arranged at the bottom of the slider, and the first rack cooperates with the first gear and can slide back and forth; therefore, through the movement of the first gear, the first rack can be driven to move, and then the slider is driven to slide in the mounting groove, so as to adjust the front and rear position of the emitting lens, realize changing the position of the light source at the focal point of the emitting lens, and then changing the diffusion angle of the emitting lens to the light, so as to switch between focusing and diffusion types of light spots of different sizes; the focused light spot can detect small objects, and the diffused light spot can detect objects with hollows and narrow slits.

[0032] Furthermore, a first knob 44 is provided on the housing 1 to drive the first gear 42. The first knob is installed on both sides of the housing, and the front and rear positions of the emitting lens can be adjusted by rotating the knob through the outer hexagonal holes and the inner hexagonal holes of the gear.

[0033] Therefore, in this reflective photoelectric sensor, the emitting lens is driven by the first knob, and the front and rear positions of the emitting lens can be adjusted by adjusting the first knob, thereby adjusting the size of the light spot.

[0034] like Figure 6 As shown, the specific spot focusing and diffusion adjustment process is as follows: There are two first knobs synchronously arranged on the side of the housing. Adjusting the first knob drives the emitting lens to move forward and backward, so that the light-emitting tube moves from the focal point to a position less than the focal point, and the light spot changes from focusing to diffusion; S1. Focused light spot: the light tube is at the focus of the lens, and the light is refracted by the lens into parallel light, forming a focused small light spot; S2. Diffused light spot: the light-emitting tube is smaller than the focal position, which shortens the object distance, expands the diffusion angle of the refracted light, and forms a large diffuse light spot.

[0035] The light source of the emitter can form different light spots by adjusting the focus. The emitter is at the lower part of the product. In the initial state, the light-emitting LED is at the standard focus of the lens. At this time, the light is refracted by the lens and becomes parallel light, and the light spot formed is a small light spot. Adjust the first knob, turn the first knob on the side clockwise to drive the first gear, and the first gear engages with the first rack to drive the lower bracket to move backward, shortening the focal length, shortening the object distance, and expanding the diffusion angle of the refracted light to form a large light spot.

[0036] At the same time, the light-emitting aperture diaphragm is used to turn the LED light source into a point light source with a relatively small divergence angle, block stray light, and adjust the size of the light spot so that the product can meet the needs of different scenes and can achieve stable detection of objects of different sizes and objects with uneven surfaces.

[0037] In one or more embodiments, Figure 5 As shown, the detection distance adjustment mechanism 5 includes a driven member and a worm 52 driving the driven member, the driven member includes an inner ring turbine 53 and an outer ring second gear 51, and the worm 52 and the turbine 53 are meshed; The receiving lens 3 is provided with a second rack 55 , and the second rack 55 is meshed with the second gear 51 .

[0038] Specifically, the receiving lens is provided with a second rack that meshes with the gear of the turbine, and the rotation of the turbine can drive the receiving lens to move up and down; the driven member is a double-toothed member, which is composed of the turbine of the inner ring and the gear of the outer ring, and transmits the rotation of the worm knob to the receiving lens, and prevents vibration through self-locking; Currently, the sensor detection distance is very sensitive. A slight change in the lens position will affect the detection distance. The thread matching method will cause the thread to loosen and shift due to vibration, just like bolts need to be tightened with anti-loosening washers to prevent loosening when subjected to vibration. Ordinary reflective sensors use knobs for adjustment and do not add anti-loosening washers, which cannot prevent the knob from shifting during vibration. Worm gears have their own anti-loosening function because they are self-locking and will not loosen and shift due to vibration, affecting the detection distance.

[0039] In one or more embodiments, the transmission ratio of the detection distance adjustment mechanism 5 is 30, and the radius of the second gear 51 is 1.5 mm.

[0040] The current sensor adjustment accuracy is difficult to improve. The transmission of the thread is adjusted by one circle (one pitch). The higher the accuracy, the smaller the pitch processing is required, but the processing difficulty and cost will become very high. 0.4mm pitch is generally used. It is difficult to process threads with a pitch smaller than 0.4mm. The present application adopts a worm gear mechanism, which is achieved by adjusting the transmission ratio; the internal space of the sensor described in the present application meets the theoretical adjustment accuracy, which is not only higher than 0.4mm but can even be finer; when the transmission ratio i=30, the gear R=1.5mm, the same adjustment of the lens movement amount for one circle is sin6*2*1.5≈0.32mm, and the parts can be processed as long as there is enough space i=30 worm gear; the second gear and the lens are engaged with gears, and rotating the second gear can move the lens up and down to achieve high-precision adjustment.

[0041] Understandably, in the sensor, the adjustment of the spot size requires extremely high precision to ensure stable detection in different application scenarios. Therefore, setting the transmission ratio to 30 can greatly improve the adjustment accuracy of the spot size. Although the larger the transmission ratio, the smaller the transmission force will be, in the spot adjustment mechanism, since only the slight movement of the emitting lens needs to be adjusted, the transmission force does not need to be too large. On the contrary, it is more important to ensure the stability and efficiency of the transmission. Through a reasonable transmission ratio setting (the transmission ratio is set to 30), it can be ensured that the transmission mechanism can work smoothly and efficiently during the rotation of the knob. By setting the transmission ratio to 30, the overall performance and stability of the sensor can be ensured while meeting the adjustment accuracy.

[0042] It is understandable that the size of the gear radius directly affects the efficiency and accuracy of the transmission. Under the same torque, the larger the gear radius, the greater the transmission force, but it will also increase the friction and wear between the gears. By setting the gear radius to 1.5mm, the friction and wear between the gears can be reduced while ensuring sufficient transmission force, thereby optimizing the transmission efficiency; the overall structural size of the sensor is limited. By setting the radius of the second gear to 1.5mm, the compactness and aesthetics of the overall structure of the sensor can be ensured while meeting the transmission requirements; and the smaller the gear radius, the greater the angle of gear rotation under the same torque. This feature allows only a small torque to be applied to achieve a larger adjustment effect when adjusting the spot size. Thereby improving the sensitivity of the spot adjustment.

[0043] It is understandable that when the lead angle of the worm is less than the equivalent friction angle between the meshing gear teeth, the mechanism has self-locking properties and can achieve reverse self-locking, that is, the worm can only drive the worm wheel, but the worm wheel cannot drive the worm. In this application, when the transmission ratio is 30, the worm rotates one circle and the turbine only rotates 1 / 30 circle. This small angle rotation increases the contact area and contact time between the turbine and the worm, thereby enhancing the friction and self-locking effect.

[0044] Furthermore, in one or more embodiments, a second knob 54 for driving the worm 52 is also provided on the housing 1. The second knob 54 is a plastic knob with a cross groove pan head and screw thread, which is installed on the product housing, and rotating the second knob can rotate the turbine.

[0045] like Figure 7 The adjustment process of the detection distance is as follows: S1. Transmission of worm and worm gear The worm is a rod-shaped component with spiral teeth, which transmits power by meshing with the spiral tooth grooves of the turbine. When the worm rotates, the turbine rotates with it and drives the second rack on the receiving lens to move up and down through the second gear on its outer ring.

[0046] S2. Up and down movement of the receiving lens The receiving lens is installed in the mounting groove on the upper bracket and can move up and down along the vertical direction of the groove. When the worm rotates to drive the turbine and the second gear to rotate, the second gear will mesh with the second rack on the receiving lens, thereby driving the receiving lens to move up and down.

[0047] S3. Adjustment of detection distance According to the principle of triangulation, when the receiving lens moves up and down, the sensor's detection distance to the object will change; when the receiving lens moves upward, the sensor's detection distance to the object will become farther; conversely, when the receiving lens moves downward, the detection distance will become closer. Therefore, by rotating the second knob, the up and down position of the receiving lens can be easily adjusted, thereby achieving precise adjustment of the detection distance.

[0048] In one or more embodiments, a light emitting tube 21 is disposed on the housing 1; a light emitting aperture diaphragm 22 is disposed between the light emitting tube 21 and the emitting lens 2; the light emitting tube 21 obtains a suitable light spot through the diaphragm. Specifically, the light emitting tube is mounted on a substrate and then riveted to the housing.

[0049] In one or more embodiments, a binary receiver 7 is further included, and the binary receiver 7 is used to receive the optical signal. Specifically, when the light beam emitted by the transmitting lens hits the object to be measured, the reflected light beam will be captured by the receiving lens and focused on the binary receiver. The binary receiver can sensitively sense the change of the optical signal, thereby realizing the detection of whether the object exists or not.

[0050] In one or more embodiments, a lens 8 is further included, and the lens 8 is disposed on the housing 1 and laser welded on the housing. Specifically, the lens is installed on the front part of the housing to protect the transmitting lens and the receiving lens from dust and water vapor or other materials.

[0051] In summary, in the present application, the worm gear mechanism with a large transmission ratio makes the up and down movement adjustment of the receiving lens more precise. When the worm rotates, the position of the receiving lens is finely adjusted through the close meshing of the turbine and the worm, and the precise matching of the second gear on the outer ring of the turbine and the second rack on the receiving lens. This fine-tuning capability enables the light to be more accurately irradiated onto the binary receiver after passing through the optical lens.

[0052] Since the worm gear mechanism provides a more precise lens position adjustment, the light can produce a more precise change in light intensity when it shines on the binary receiver. This change is captured by the binary receiver and converted into an electrical signal, which is then processed by the internal logic algorithm to obtain a more accurate switch signal feedback.

[0053] Therefore, the worm gear mechanism with a large transmission ratio not only improves the accuracy of adjusting the distance, but also indirectly improves the resolution of visible light detection. This setting enables the sensor to detect the presence of objects more stably and accurately in complex environments, thereby meeting the needs of more application scenarios.

[0054] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A reflective photoelectric sensor with high visible light resolution and adjustable spot size, comprising a housing (1), characterized in that: Also includes: An emitting lens (2) for emitting a light beam; the emitting lens (2) is arranged in the housing (1); A receiving lens (3) for receiving the reflected light beam; A light spot adjustment mechanism (4) is used to drive the emitting lens (2) to move, thereby changing the size of the light spot; The detection distance adjustment mechanism (5) is used to drive the receiving lens (3) to move.

2. The reflective photoelectric sensor according to claim 1, characterized in that: The emitting lens (2) is provided with a slider (41); the light spot adjustment mechanism (4) comprises a first gear (42) and a first rack (43) meshing with the first gear (42); the first rack (43) is provided on the slider (41).

3. The reflective photoelectric sensor according to claim 1, wherein: The detection distance adjustment mechanism (5) comprises a driven member and a worm (52) driving the driven member, the driven member comprising an inner ring turbine (53) and an outer ring second gear (51), the worm (52) and the turbine (53) being meshed; The receiving lens (3) is provided with a second rack (55), and the second rack (55) is meshed with the second gear (51).

4. The reflective photoelectric sensor according to claim 3, characterized in that: The transmission ratio of the detection distance adjustment mechanism (5) is 30, and the radius of the second gear (51) is 1.5 mm.

5. The reflective photoelectric sensor according to claim 1, wherein: The invention comprises an upper bracket (61) and a lower bracket (62), wherein the upper bracket (61) is mounted on the upper part of the housing (1), and the lower bracket (62) is mounted on the lower part of the housing (1); the receiving lens (3) is arranged on the upper bracket (61); and the transmitting lens (2) is arranged on the lower bracket (62).

6. The reflective photoelectric sensor according to claim 1, wherein: A light-emitting tube (21) is arranged on the housing (1); a light-emitting aperture diaphragm (22) is arranged between the light-emitting tube (21) and the emitting lens (2); and the light-emitting tube (21) obtains a suitable light spot through the diaphragm.

7. The reflective photoelectric sensor according to claim 3, characterized in that: A second knob (54) for driving the worm (52) to move is also provided on the housing (1).

8. The reflective photoelectric sensor according to claim 1, wherein: It also comprises a binary receiver (7), wherein the binary receiver (7) is used to receive the optical signal.

9. The reflective photoelectric sensor according to claim 1, wherein: It also comprises a lens (8), wherein the lens (8) is arranged on the housing (1).

10. The reflective photoelectric sensor according to claim 2, characterized in that: A first knob (44) for driving the first gear (42) to move is also provided on the housing (1).

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