A tof laser displacement sensor

Abstract

The application relates to the technical field of laser ranging, in particular to a TOF (Time of Flight) laser displacement sensor which comprises a shell, a support, an optical module and a circuit module, the optical module comprises a laser emitter, a transmitting lens, a receiving lens and a stepped light absorption structure, the optical module is fixed on the support, the transmitting lens and the receiving lens are arranged in parallel, the transmitting lens is arranged in front of the laser emitter, the stepped light absorption structure is arranged behind the receiving lens, the stepped light absorption structure is arranged behind a light signal receiver, the light signal is received and the measurement result is calculated through the circuit module. An optical surface is further arranged on the receiving lens, the optical surface can change the refraction angle of light, and light in the near place can also converge on the light signal receiver. The application has the effects of low installation precision requirement, convenient installation and manufacturing and measurement of objects in the near place.

Description

Technical Field

[0001] This application relates to the field of laser ranging technology, and in particular to a TOF laser displacement sensor. Background Technology

[0002] Time-of-Flight (TOF) laser displacement sensors are widely used in industrial automation, robot navigation, logistics sorting, security monitoring, and many other fields due to their advantages such as high measurement accuracy, fast response speed, and non-contact measurement. Their basic principle is to calculate precise distance information by measuring the round-trip time of a laser pulse between the sensor and the target object.

[0003] The core components of current TOF laser displacement sensors are optical components and circuit boards. Optical components generally include laser emitters, receiving lenses, total internal reflection lenses, etc. The laser emitter emits laser light towards the object being measured. After being reflected by the object, the receiving lens receives the returned signal, which is then refracted by the total internal reflection lens and enters the light signal receiver on the circuit board. The distance to the object is then calculated by the processing unit on the circuit board.

[0004] However, the total internal reflection lens used in the existing TOF laser displacement sensor has an aspherical and prism structure, which requires very precise optical design and processing, resulting in high cost. It also requires high installation accuracy and must be strictly aligned with the sensor. Any slight deviation will cause the light spot to deviate from the photosensitive surface, resulting in severe signal attenuation. Therefore, repeated adjustments are required during assembly, leading to low manufacturing efficiency. Summary of the Invention

[0005] This application provides a TOF laser displacement sensor to solve the problem of low efficiency caused by repeated debugging in the manufacturing of existing TOF laser displacement sensors.

[0006] This application provides a TOF laser displacement sensor, which adopts the following technical solution: Includes housing, bracket, optical module, and circuit module; The bracket is fixedly connected inside the housing, and the bracket is used to fix the light module and the circuit module; The optical module includes a laser emitter, a receiving lens, and a stepped light-absorbing structure. The laser emitter and the receiving lens are mounted on a bracket, and the laser emitter is fixed to a circuit module. The receiving lens has an optical surface for refracting light reflected from nearby objects. The stepped light-absorbing structure is mounted behind the receiving lens and fixedly connected to it. The stepped light-absorbing structure has steps inside and an opening at its tail for light to pass through. The stepped light-absorbing structure is used to absorb light refracted by the receiving lens to the inner wall of the stepped light-absorbing structure. The circuit module is equipped with an optical signal receiver corresponding to the stepped light-absorbing structure. The optical signal receiver is used to receive optical signals, and the circuit module is used to process the optical signals.

[0007] By adopting the above technical solution, the receiving lens is mounted on the bracket, and the stepped light-absorbing structure is fixedly connected to the receiving lens. The stepped light-absorbing structure has low installation accuracy requirements and is easy to install. The stepped light-absorbing structure absorbs light that does not enter the receiving sensor according to the specified light path, reducing interference. At the same time, an optical plane is set on the receiving lens to change the refraction angle, so that light from nearby objects can also reach the optical signal receiver, which is convenient for measuring the distance of nearby objects.

[0008] Preferably, the optical module further includes a emitting lens, which is disposed in front of the laser emitter and is fixedly connected to the bracket.

[0009] By adopting the above technical solution, a emitting lens is set in front of the laser emitter to convert the light emitted from the laser emitter into parallel light, thereby reducing the distance error.

[0010] Preferably, a light-blocking block is connected to the emitting lens, and the light-blocking block is fixedly connected to the bracket. The light-blocking block is used to separate the emitting lens and the receiving lens.

[0011] By adopting the above technical solution, a light-blocking block is set between the transmitting lens and the receiving lens to prevent the light emitted from the transmitting lens from directly entering the receiving lens, thus isolating the transmitted light from interfering with the receiving area.

[0012] Preferably, a filter plate is provided on the outer casing, the filter plate is fixedly connected to the outer casing, and the filter plate is used to filter light and retain only infrared light.

[0013] By adopting the above technical solution, light is filtered out by a filter plate, leaving only infrared light. Since infrared light has better penetration, it has a higher effective range and reliability in complex situations.

[0014] Preferably, the circuit module includes a main circuit board and a side circuit board; the main circuit board is fixedly connected to the bracket, and a light signal receiver is provided on the main circuit board at a position corresponding to the stepped light-absorbing structure; the side circuit board is fixedly connected to the main circuit board, and the side circuit board is located below the bracket and is also fixedly connected to the bracket, and the main circuit board and the side circuit board together complete the processing of the light signal.

[0015] By adopting the above technical solution, the main circuit board and the side circuit board are fixed on the bracket, making the main circuit board and the side circuit board and the bracket a whole, thus ensuring the stability of the main circuit board and the side circuit board.

[0016] Preferably, the outer casing is provided with a button hole and a display screen hole, which are used to accommodate the button and the display screen; the button is mounted on a support frame, which is fixedly connected to the inner wall of the outer casing, and the support frame is provided with a display screen mounting slot, which is used to mount the display screen.

[0017] By adopting the above technical solution, the TOF laser displacement sensor can be controlled by buttons, and the measurement results can be displayed on the screen, making the results visible.

[0018] Preferably, the circuit module further includes a button circuit board, which is fixed on the support frame and fixedly connected to the main circuit board. The button circuit board is used to receive button signals and output the processing results to the display screen.

[0019] By adopting the above technical solution, signal transmission between the buttons and the screen and the main circuit board and the side circuit board is realized through the button circuit board.

[0020] Preferably, it also includes a power cord for supplying power to the entire device. The power cord extends through the housing and into the housing. A tail plug is provided between the power cord and the housing. The power cord passes through the tail plug. A second sealing ring is provided between the tail plug and the outer wall of the housing. A limiting piece is provided between the tail plug and the inner wall of the housing.

[0021] By adopting the above technical solution and setting a tail plug, the power cord and the outer casing are sealed, ensuring the airtightness of the entire device.

[0022] Preferably, it also includes a cover plate, the cover plate having a groove around its edge, a first sealing ring being disposed in the groove, and the cover plate being fixedly connected to the outer shell.

[0023] By adopting the above technical solution, the cover plate is used to seal the outer shell. A groove is set on the cover plate, and a first sealing ring is set in the groove to achieve a seal between the cover plate and the outer shell.

[0024] In summary, the present invention has at least one of the following beneficial technical effects: 1. The stepped light-absorbing structure has low requirements for installation accuracy and high manufacturing efficiency. The stepped light-absorbing structure absorbs light that does not enter the sensor according to the specified light path, reducing interference and making the measurement results more accurate. At the same time, the stepped light-absorbing structure is easy to install. The optical surface set on the receiving lens can change the angle of light, so that objects at close range can also be measured. 2. By setting a light-blocking block next to the emitting lens, interference from the light from the emitting lens to the receiving lens is avoided. At the same time, a filter plate is set on the outer shell to retain only infrared light. Since infrared light has good penetration, the accuracy of the measurement results can be guaranteed even under complex conditions. 3. By setting a second sealing ring between the tail plug and the outer shell, and setting a first sealing ring in the groove of the cover plate, multiple sealing measures work together to give the entire TOF laser displacement sensor a good sealing and waterproof effect. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the TOF laser displacement sensor of this application; Figure 2 This is a schematic diagram of the internal structure of a TOF laser displacement sensor; Figure 3 This is a schematic diagram of the cross-sectional structure of a TOF laser displacement sensor; Figure 4 This is a schematic diagram of the positional relationship of the circuit modules; The attached diagram is labeled as follows: 1. Outer shell; 101. Filter; 102. Keypad hole; 103. Display hole; 104. Key; 105. Display screen; 106. Support frame; 107. Display screen mounting slot; 108. Lampshade; 109. Glue dispensing groove; 110. Cover plate; 111. Groove; 112. First sealing ring; 113. Tail plug; 114. Second sealing ring; 115. Limiting piece; 116. Power cord; 2. Bracket; 201. First mounting hole; 202. Second mounting hole; 3. Optical module; 301. Laser emitter; 302. Emitting lens; 303. Receiving lens; 304. Stepped light absorption structure; 305. Light blocking block; 306. Optical surface; 4. Circuit module; 401. Main circuit board; 402. Side circuit board; 403. Keypad circuit board; 404. Optical signal receiver. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1-4 The present invention will be described in further detail below.

[0027] The applicant discovered that existing TOF laser displacement sensors use a total internal reflection lens behind the receiving lens to focus light onto the optical signal receiver. This requires very precise optical design and manufacturing due to the aspherical and prism structure, as well as high installation accuracy and multiple adjustments during assembly.

[0028] To address the aforementioned issues, this application provides a TOF laser displacement sensor that uses a stepped light-absorbing structure 304 to absorb light that does not enter the sensor according to the prescribed optical path, resulting in clearer imaging. Furthermore, the opening at the tail of the stepped light-absorbing structure 304 only needs to be roughly aligned with the optical signal receiver 404 on the main circuit board 401, thus requiring low precision.

[0029] This application discloses a TOF laser displacement sensor. (Refer to...) Figure 1 and Figure 2The TOF laser displacement sensor includes a housing 1, a bracket 2, an optical module 3, and a circuit module 4.

[0030] The outer casing 1 serves to support and protect the internal structure. One side of the outer casing 1 has a filter 101 mounting hole for installing a filter 101. The filter 101 is placed within the mounting hole and is fixedly connected to the outer casing 1. Waterproof adhesive is applied between the filter 101 and the outer casing 1. The filter 101 filters light, retaining only infrared radiation. The waterproof adhesive ensures a good seal between the filter 101 and the outer casing 1.

[0031] On the other side of the outer casing 1, there is a button 104 hole and a display screen hole 103. The button 104 is fixedly connected to the support frame 106 at the rear. The button 104 is located in the button 104 hole and is slidably connected to the outer casing 1. A button 104 sticker is affixed to the button 104. The button 104 label is pasted to the outer surface of the outer casing 1 through the overall adhesive layer on its back, completely covering the entire button 104 area, thus forming a continuous and seamless sealing layer, which can both transmit the action of the button 104 and effectively prevent water and dust.

[0032] A support frame 106 is fixed to the outer casing 1. A display screen mounting slot 107 is provided on the support frame 106, and the display screen 105 is installed in the display screen mounting slot 107, while the display screen 105 is also fixedly connected to the outer casing 1. A lampshade 108 is provided on one side of the display screen 105. The lampshade 108 is fixedly connected to the outer casing 1 by adhesive injected into the adhesive dispensing groove 109 of the outer casing 1. An indicator light is provided inside the lampshade 108 to display the status of the TOF laser displacement sensor.

[0033] The outer casing 1 is also provided with a cover plate 110. Near the edge of the cover plate 110, there is a groove 111 around the cover plate 110. A first sealing ring 112 is provided in the groove 111. The cover plate 110 and the outer casing 1 are fixedly connected by bolts. After fixing, the first sealing ring 112 performs the sealing function.

[0034] refer to Figure 3 A tail plug 113 is provided on the other side of the outer casing 1. The power cord 116 of the device is located inside the tail plug 113. The tail plug 113 passes through the outer casing 1. A second sealing ring 114 is provided between the tail plug 113 and the outer side of the outer casing 1 to achieve a seal between the tail plug 113 and the TOF laser displacement sensor. A limiting piece 115 is provided between the tail plug 113 and the inner side of the outer casing 1 to fix the tail plug 113 and restrict the movement of the tail plug 113.

[0035] The bracket 2 is fixedly connected to the outer shell 1. The bracket 2 is provided with a first mounting hole 201 and a second mounting hole 202 for mounting the optical module 3. The first mounting hole 201 penetrates the bracket 2 to form a passage. The circuit module 4 is also fixedly connected to the bracket 2.

[0036] The optical module 3 includes a laser emitter 301, an emitting lens 302, a receiving lens 303, and a stepped light-absorbing structure 304. The laser emitter 301 is mounted in the first mounting hole 201 of the bracket 2, and the other end of the laser emitter 301 is fixed to the circuit module 4. The laser emitter 301 is used to generate laser light. The emitting lens 302 is mounted at the other end of the first mounting hole 201 and is used to adjust the laser light emitted by the laser emitter 301 into parallel light.

[0037] The receiving lens 303 is installed within the second mounting hole 202, and is arranged parallel to the transmitting lens 302. An optical surface 306 is provided on the edge of the receiving lens 303. The optical surface 306 is spherical, and the distance between the center of the optical surface 306 and the center of the receiving lens 303 is 6.2 mm. The area of ​​the optical surface 306 accounts for 3%-10% of the area of ​​the receiving lens 303. The refraction angle of the optical surface 306 is larger than that of the receiving lens 303, and it is used to focus near-end light rays, enabling nearby objects to be measured. Near-end light rays are the light rays reflected from nearby objects.

[0038] A stepped light-absorbing structure 304 is provided behind the receiving lens 303. The stepped light-absorbing structure 304 has multiple steps inside, and the steps are made of matte black to absorb light that does not enter the sensor according to the prescribed optical path and reduce interference. The end of the stepped light-absorbing structure 304 is provided with an opening for light to pass through. The prescribed optical path is that the light can pass through the opening at the end of the stepped light-absorbing structure 304 after being refracted by the receiving lens 303.

[0039] A light-blocking block 305 is provided between the transmitting lens 302 and the receiving lens 303. The light-blocking block 305 is located in front of the transmitting lens 302 and is fixedly connected to the bracket 2. The light-blocking block 305 is made of opaque material and is used to isolate the interference of the emitted light on the receiving lens 303.

[0040] For details, please refer to Figure 3 and Figure 4The circuit module 4 includes a main circuit board 401, a side circuit board 402, and a button circuit board 403. The main circuit board 401 is located behind the optical module 3 and is fixedly connected to the bracket 2. One end of the laser emitter 301 is soldered to the main circuit board 401. A light signal receiver 404 is positioned behind the stepped light-absorbing structure 304 on the main circuit board 401. The main circuit board 401 also has a transmitting module for controlling the laser emitter 301 to emit laser light. The side circuit board 402 is fixedly connected to the main circuit board 401, specifically by soldering. The side circuit board 402 is also bolted to the bracket 2. The side circuit board 402 contains a power module, a control module, and a protection module, providing voltage regulation, isolation, protection, and filtering. The main circuit board 401 controls the laser emitter 301 to emit laser light. After the light signal receiver 404 receives the returned light signal, the main circuit board 401 and the side circuit board 402 jointly process the signal and calculate the result. The main circuit board 401 and the side circuit board 402 in this application are conventional configurations in the art, and their circuit principles are common knowledge in the art. This application will not explain them in detail.

[0041] The button circuit board 403 is located behind the support frame 106 and is fixed to the support frame 106 by bolts. The button circuit board 403 is also soldered to the main circuit board 401. The button circuit board 403 is electrically connected to the main circuit board 401 and the side circuit board 402. The button circuit board 403 is used to receive signals from the button 104 and transmit the signals from the button 104 to the main circuit board 401 and the side circuit board 402. At the same time, it receives the processing results from the main circuit board 401 and the side circuit board 402 and transmits them to the display screen 105.

[0042] The implementation principle of the TOF laser displacement sensor in this embodiment is as follows: the laser emitter 301 generates laser light, which is adjusted to parallel light by the emitting lens 302 and passes through the filter 101 to retain only infrared light. After illuminating the object, the light returns and passes through the filter 101 again, retaining red light. After passing through the receiving lens 303, the light is focused to the optical signal receiver 404. Light that does not enter the sensor according to the prescribed optical path is absorbed by the stepped light absorption structure 304 to reduce interference. For nearby objects, the light is refracted at a large angle at the optical surface 306 to the optical signal receiver 404, thus achieving the effect of measuring the distance to both near and far objects.

[0043] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A TOF laser displacement sensor, characterized in that: It includes a housing (1), a bracket (2), an optical module (3), and a circuit module (4); The bracket (2) is fixedly connected inside the outer shell (1), and the bracket (2) is used to fix the light module and the circuit module (4). The optical module (3) includes a laser emitter (301), a receiving lens (303), and a stepped light-absorbing structure (304). The laser emitter (301) and the receiving lens (303) are mounted on a bracket (2). The laser emitter (301) is fixed on a circuit module (4). An optical surface (306) is provided on the receiving lens (303), which is used to refract light reflected from nearby objects. The stepped light-absorbing structure (304) is installed behind the receiving lens (303) and is fixedly connected to the receiving lens (303). The stepped light-absorbing structure (304) has a step inside and an opening at the tail for light to pass through. The stepped light-absorbing structure (304) is used to absorb light refracted by the receiving lens (303) to the inner wall of the stepped light-absorbing structure (304). The circuit module (4) is provided with an optical signal receiver (404) corresponding to the stepped light-absorbing structure (304). The optical signal receiver (404) is used to receive optical signals, and the circuit module (4) is used to process the optical signals.

2. The TOF laser displacement sensor according to claim 1, characterized in that: The optical module (3) also includes an emitting lens (302), which is located in front of the laser emitter (301) and is fixedly connected to the bracket (2).

3. The TOF laser displacement sensor according to claim 2, characterized in that: A light-blocking block (305) is provided in front of the emitting lens (302). The light-blocking block (305) is fixedly connected to the bracket (2). The light-blocking block (305) is used to separate the emitting lens (302) and the receiving lens (303).

4. The TOF laser displacement sensor according to claim 1, characterized in that: A filter plate is provided on the outer shell (1). The filter plate is fixedly connected to the outer shell (1). The filter plate is used to filter light and retain only infrared light.

5. The TOF laser displacement sensor according to claim 1, characterized in that: The circuit module includes a main circuit board (401) and a side circuit board (402); the main circuit board (401) is fixedly connected to the bracket (2), and the optical signal receiver (404) is disposed on the main circuit board (401); the side circuit board (402) is fixedly connected to the main circuit board (401), and the side circuit board (402) is located below the bracket (2) and is also fixedly connected to the bracket (2).

6. The TOF laser displacement sensor according to claim 1, characterized in that, The outer casing (1) is provided with a button (104) hole and a display screen hole (103). The button (104) hole and the display screen hole (103) are used to accommodate the button (104) and the display screen (105). The button (104) is mounted on a support frame (106). The support frame (106) is fixedly connected to the inner wall of the outer casing (1). The support frame (106) is provided with a display screen mounting slot (107). The display screen mounting slot (107) is used to install the display screen (105).

7. The TOF laser displacement sensor according to claim 6, characterized in that: The circuit module also includes a button circuit board (403), which is fixed on the support frame (106) and fixedly connected to the main circuit board (401). The button circuit board (403) is used to receive the button (104) signal and output the processing result to the display screen (105).

8. The TOF laser displacement sensor according to claim 1, characterized in that, It also includes a cover plate (110), which is provided with a groove (111) around the edge, and a first sealing ring (112) is provided in the groove (111). The cover plate (110) is fixedly connected to the outer shell (1).

9. The TOF laser displacement sensor according to claim 1, characterized in that, It also includes a power cord (116) for supplying power to the entire device. The power cord (116) extends through the housing (1) into the housing (1). A tail plug (113) is provided between the power cord (116) and the housing (1). The power cord (116) passes through the tail plug (113). A second sealing ring (114) is provided between the tail plug (113) and the outer wall of the housing (1). A limiting piece (115) is provided between the tail plug (113) and the inner wall of the housing (1).

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