A pulse laser rangefinder receiving component capable of eliminating short-range scattering

Abstract

The invention discloses a pulse laser rangefinder receiving component capable of eliminating short-range scattering, belonging to the technical field of laser ranging. A high-speed motor is connected to the center of a shielding turntable, and a target reflected echo passes through the shielding turntable from the other side and enters an APD detector; light emitted by an LED passes through the shielding turntable from the other side and enters a PIN phototube; a control circuit drives the high-speed motor to rotate and receives and processes the ranging laser echo signal and the PIN phototube trigger signal, and sends a trigger signal to trigger a laser emission module to emit a laser pulse. The invention shields the APD detector for a period of time after the laser pulse is emitted by rotating the shielding area and the light-passing area designed on the shielding turntable, thereby eliminating the phenomenon of deep saturation or even damage to the APD detector caused by strong backscattered light of the laser pulse in the laser rangefinder, effectively reducing the ranging blind area of ​​the laser rangefinder, and preventing damage to the detector.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser ranging, and more particularly, relates to a pulse laser rangefinder receiving component capable of eliminating short-range scattering. Background Art

[0002] A pulse laser rangefinder is a device that measures the distance to a remote target. It has the characteristics of long measurement range, high measurement accuracy, simple structure, and low power consumption. It is widely used in surveying and mapping, aviation, aerospace and other fields. A pulse laser rangefinder is generally composed of components such as a laser emission module, a receiving lens, a receiving detection module, and a control circuit. The pulse laser rangefinder calculates the target distance by measuring the round-trip flight time of the laser pulse to the target. In order to improve the range, the receiving detection module of the pulse laser rangefinder generally uses an avalanche photodiode (APD) as a laser echo pulse detection device. The APD detector has high sensitivity, but requires a higher bias voltage to increase the gain, and strong light can easily cause it to deeply saturate or damage it. Therefore, the pulse laser rangefinder generally has a short-range detection blind spot (generally between tens of meters and hundreds of meters).

[0003] When a pulsed laser propagates over short distances, it generates strong backscattered light. When this light enters an APD detector, it saturates the detector for an extended period (several microseconds to tens of microseconds), rendering it unable to detect target signals within short ranges (hundreds to thousands of meters). Backscattered light is primarily generated by particles in the air and the surfaces of some optical components. This is particularly true in multi-sensor shared optical systems or devices with a shared optical path, where residual reflections from various optical components are difficult to eliminate. This often results in extremely strong short-range scattered or reflected light entering the APD detector, causing deep saturation (saturation lasting more than tens of microseconds) and even damage. To minimize the effects of short-range scattering on the detector, the detector bias voltage is often reduced during the period when the detector responds to short-range signals to reduce the short-range gain and prevent deep saturation. However, this method cannot eliminate the effects of strong short-range scattering on the detector. When the short-range scattered light is strong, even reducing the gain on the APD detector to the minimum will still result in deep saturation, potentially even damaging the detector target surface. Summary of the Invention

[0004] In order to solve the impact of strong short-range scattering on the APD detector of a pulsed laser rangefinder, the present invention provides a receiving component for a pulsed laser rangefinder. The receiving component can eliminate the deep saturation or damage of the APD detector caused by the short-range scattering of the ranging laser by high-speed shielding of the APD detector, effectively reducing the ranging blind area of ​​the laser rangefinder and preventing damage to the detector.

[0005] To achieve the above object, the present invention provides a pulse laser rangefinder receiving assembly capable of eliminating short-range scattering, comprising: a shielding turntable, a high-speed motor, an APD detector, a PIN phototube, an LED light-emitting diode and a control circuit;

[0006] The high-speed motor is connected to the center of the shielding turntable and drives the shielding turntable to rotate at a high and uniform speed. The APD detector is located on one side of the shielding turntable and is close to the edge of the shielding turntable. The target reflected echo passes through the shielding turntable from the other side of the shielding turntable and enters the APD detector, generating a ranging laser echo signal; the PIN phototube is located on the same side of the shielding turntable as the APD detector and is close to the edge of the shielding turntable. The LED light-emitting diode is located on the other side of the shielding turntable. The light emitted by the LED light-emitting diode passes through the shielding turntable from the other side of the shielding turntable and enters the PIN phototube, generating a PIN phototube trigger signal;

[0007] The control circuit drives the high-speed motor to rotate and receives the ranging laser echo signal generated by the APD detector and the PIN phototube trigger signal generated by the PIN phototube. The control circuit sends a trigger signal to trigger the laser emission module to emit a laser pulse by processing the received ranging laser echo signal and the PIN phototube trigger signal.

[0008] The shielding turntable is provided with a shielding turntable APD light-transmitting area and a shielding turntable PIN light-transmitting hole. The shielding turntable is circular, and the center of the shielding turntable is connected to the rotating shaft of the high-speed motor. The shielding turntable rotates at a high speed with the center of the circle as the axis. The areas on the shielding turntable except the shielding turntable APD light-transmitting area and the shielding turntable PIN light-transmitting hole are all shielding areas. The shielding area on the shielding turntable needs to pass over the photosensitive surface of the APD detector at high speed.

[0009] In some optional embodiments, the length of the shielding area on the shielding turntable across the photosensitive surface of the APD detector and the size of the photosensitive surface of the APD detector satisfy: ωt4R>>d APD , where d APD is the diameter of the photosensitive surface of the APD detector, R is the distance between the photosensitive surface of the APD detector and the center of the shielding turntable, t4 is the blind time of the laser rangefinder, and ω is the speed of the high-speed motor.

[0010] In some optional embodiments, the LED light emitting diode is in a constantly on state. When the blocking area of ​​the blocking turntable is between the LED light emitting diode and the photosensitive surface of the PIN phototube, the PIN phototube cannot receive the light signal of the LED light emitting diode. When the PIN light hole of the blocking turntable passes between the LED light emitting diode and the photosensitive surface of the PIN phototube at high speed, the PIN phototube will briefly receive a pulse light signal from the LED light emitting diode. The pulse light signal is the PIN phototube trigger signal. At this time, the APD detector photosensitive surface is in a blocked state, and the angle from the starting point of the APD light passing area of ​​the blocking turntable is θ1. The corresponding passing time is t1=θ1 / ω. The control circuit generates a laser pulse trigger signal with a delay of t2 according to the PIN phototube trigger signal, which is used to trigger the laser emission module to emit a laser pulse. The moment when the laser pulse is emitted is the laser pulse signal At the moment when the signal is generated, a fixed delay t3 is generated between the laser pulse trigger signal and the laser pulse signal. The laser pulse signal is the starting point of the laser ranging timing. The time from the laser pulse signal to the APD detector photosensitive surface entering the edge of the APD light-transmitting area of ​​the shielding turntable is t4, which is the short-range blind area of ​​ranging. During the time t4, the APD detector is blocked, and the short-range scattering of the laser pulse and the echo signal of the target cannot enter the APD detector. The influence of the short-range scattered light on the APD detector is completely eliminated. The laser pulse signal is used as the starting point of the laser ranging timing. After time t5, the APD detector receives the target echo signal, then the target distance value is ct5 / 2, c is the speed of light, and the rotation angle θ2 corresponding to the APD light-transmitting area of ​​the shielding turntable APD needs to ensure that the time for the light-transmitting area to pass through the APD detector photosensitive surface is greater than the maximum range of the laser rangefinder, that is, θ2>2Lω / c, L is the maximum range of the laser rangefinder.

[0011] In some optional embodiments, the PIN phototube and the APD detector are respectively located at two opposite edges of the shielding turntable.

[0012] In some optional embodiments, the PIN phototube and the APD detector are located on the same edge of the shielding turntable.

[0013] In some optional implementation schemes, there are n groups of shielding turntable APD light-transmitting areas and shielding turntable PIN light-transmitting holes on the shielding turntable, and they are rotationally symmetrically distributed on the shielding turntable. The rotation angle occupied by each group is 2π / n. The shielding turntable completes n ranging processes in one rotation, and n is a positive integer.

[0014] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0015] The present invention eliminates the influence of short-range scattered light on the APD detector by physically shielding the detector, which can prevent deep saturation or damage of the detector caused by strong short-range scattering. It can be used in systems such as multi-sensor common optical path equipment that are prone to extremely strong short-range scattered light, effectively reducing the ranging blind area of ​​the laser rangefinder and preventing damage to the detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of a first embodiment of the present invention;

[0017] Figure 2 Schematic diagram of the positional relationship between the light-transmitting area and the shielding area on the surface of the shielding turntable according to the first embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of the control timing of a pulse laser rangefinder provided by an embodiment of the present invention;

[0019] Figure 4 is a schematic structural diagram of a second embodiment of the present invention;

[0020] Figure 5 2. It is a schematic diagram showing the positional relationship between the light-transmitting area and the shielding area on the surface of the shielding turntable according to the second embodiment of the present invention;

[0021] The figures are marked as follows: 1-shielding turntable, 2-high-speed motor, 3-APD detector, 4-PIN phototube, 5-LED light-emitting diode, 6-control circuit, 7-shielding turntable APD light-passing area, 8-shielding turntable PIN light-passing hole, 9-PIN phototube trigger signal, 10-laser pulse trigger signal, 11-laser pulse signal, 12-target echo signal, 13-APD detector photosensitive surface, 14-PIN phototube photosensitive surface. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0023] The short-range blind area of ​​the pulse laser rangefinder is generally required to be less than 300m, and the corresponding laser round-trip flight time is only 2μs. The shielding area on the shielding turntable 1 needs to pass through the APD detector photosensitive surface 13 at high speed, and the length of the pass is much greater than the size of the APD detector photosensitive surface 13. Figure 2As shown, the shielding turntable is circular and can be made of optical glass. The center of the circle is connected to the shaft of the high-speed motor. The shielding turntable rotates at high speed with the center of the circle as the axis. Except for the APD light-transmitting area 7 and the PIN light-transmitting hole 8, the shielding turntable is the shielding area. The APD light-transmitting area and the PIN light-transmitting hole are coated with an optical anti-reflection film, and the shielding area is coated with a reflective metal film or a light-absorbing coating. The APD light-transmitting area, the PIN light-transmitting hole and the shielding area can be manufactured using a photolithography process, which can control the dimensional accuracy to the micron level.

[0024] Assume that the diameter of the APD detector photosensitive surface is d APD , the distance from the center of the shielding turntable is R, the blind time of the laser rangefinder is t4, and the angle of the shielding area during the blind time is θ, and the speed of the high-speed motor is ω, then the length of the shielding area across the photosensitive surface of the APD detector is θR = ωt4R. If you want to achieve a better shielding effect, you need ωt4R>>d APD ,Right now d APD =0.2mm, t4 = 2μs, R = 50mm. Substituting conventional values ​​into this equation yields ω>>2000rad / s, or ω>>19098rpm. Therefore, to achieve a good shielding effect, the high-speed motor must have a speed significantly greater than 19,000 rpm. With the advancement of motor technology, small motors with speeds exceeding 100,000 rpm are now common, meeting the requirements of this technical solution.

[0025] In the embodiment of the present invention, much greater than is represented by >>, such as ωt4R>>d APD , which means as follows: If ωt4R and d APD Add them together, and the approximate value of the sum is equal to ωt4R, so ωt4R is much larger than d APD , recorded as ωt4R>>d APD Generally speaking, if ωt4R is greater than d APD More than 5 times larger, it is generally believed that ωt4R>>d APD . Properties: If ωt4R>>d APD , then d can be ignored in the inexact summation calculation APD existence.

[0026] The laser ranging component completes a pulse ranging function, and the control circuit needs to press Figure 3The timing shown controls each signal. The LED and PIN phototransistor are located on either side of the shielding disc, with the LED constantly on. When the shielding disc's obstruction zone lies between the LED and the PIN phototransistor's photosensitive surface, the PIN phototransistor receives no light from the LED. However, when the shielding disc's PIN aperture passes between the two at high speed, the PIN phototransistor briefly receives a pulsed light signal from the LED, which serves as the PIN phototransistor's trigger signal. The smaller the shielding disc's PIN aperture, the narrower the PIN phototransistor trigger signal, resulting in higher trigger accuracy. However, this also results in a weaker PIN phototransistor response. Therefore, the size of the shielding disc's PIN aperture should be minimized while maintaining the PIN phototransistor's response amplitude. Figure 2 The position relationship of the blocking turntable shown is Figure 3 At the start of the PIN phototube trigger signal (time t0), the APD detector's photosensitive surface is obscured. The angle from the start of the APD's light-transmitting area on the obstruction disk is θ1, corresponding to a transit time of t1 = θ1 / ω. t1 is determined by the positional relationship between the obstruction and light-transmitting areas on the obstruction disk and the obstruction disk's rotational speed and is generally a constant value. Based on the PIN phototube trigger signal, the control circuit generates a laser pulse trigger signal with a delay of t2, which triggers the laser transmitter module to emit a laser pulse. The laser pulse emission time is the laser pulse signal generation time. A fixed delay t3 occurs between the laser pulse trigger signal and the laser pulse signal, which is determined by the laser transmitter module and is generally a fixed value. The laser pulse signal is the starting point for laser ranging timing. The time from the laser pulse signal to the APD detector's photosensitive surface entering the edge of the APD's light-transmitting area on the obstruction disk is t4, which represents the short-range blind zone for ranging. During this time, the APD detector is obscured, preventing the near-range scattered light from the laser pulse and the target's return signal from entering the detector. The laser pulse signal is used as the starting point of the laser ranging timing. After time t5, the APD detector receives the target echo signal (12). The target distance value is ct5 / 2, where c is the speed of light. Figure 3 The rotation angle θ2 corresponding to the APD light-passing area of ​​the middle obstruction turntable must ensure that the time it takes for the light-passing area to pass through the photosensitive surface of the APD detector is greater than the maximum range of the laser rangefinder, that is, θ2>2Lω / c, where L is the maximum range of the laser rangefinder. Figure 3 From the control timing relationship, it can be seen that the distance of the short-range blind zone is ct4 / 2=c(t1-t2-t3) / 2. In the formula, c, t1, and t3 are all fixed values, and only t2 is a settable value. Therefore, the distance of the short-range blind zone can be adjusted by setting the value of t2 through the control circuit to compensate for the errors caused by the high-speed motor speed and the position accuracy of the obstructed turntable.

[0027] Example 1: Figure 1 and Figure 2As shown, the pulse laser rangefinder receiving assembly capable of eliminating short-range scattering of this embodiment includes a shielding turntable 1, a high-speed motor 2, an APD detector 3, a PIN phototube 4, an LED light-emitting diode 5, and a control circuit 6. The high-speed motor 2 is connected to the center of the shielding turntable 1 and drives the shielding turntable 1 to rotate at a high and uniform speed. The APD detector 3 is located on one side of the shielding turntable 1 and is close to the edge. The target reflected echo passes through the shielding turntable 1 from the other side of the shielding turntable 1 and enters the APD detector 3; the PIN phototube 4 is located on one side of the shielding turntable 1 and is close to the edge. The LED light-emitting diode 5 is located on the other side of the shielding turntable 1. The light emitted by it passes through the shielding turntable 1 from the other side of the shielding turntable 1 and can enter When the light is transmitted to the PIN phototube 4, the LED 5 is always on. When the shielding area of ​​the shielding turntable 1 is between the LED 5 and the PIN phototube photosensitive surface 14, the PIN phototube 4 does not receive the light signal from the LED 5. When the PIN light hole 8 of the shielding turntable passes between the LED 5 and the PIN phototube photosensitive surface 14 at high speed, the PIN phototube 4 briefly receives the pulse light signal from the LED 5. This signal is the PIN phototube trigger signal 9. At this time, the APD detector photosensitive surface 13 is in the blocked state, and the angle from the starting point of the shielding turntable APD light-transmitting area 7 is θ1. The corresponding transit time is t1 = θ1 / ω. t1 is determined by the positional relationship between the shielding area and the light-transmitting area on the shielding turntable 1 and the rotation speed of the shielding turntable 1, and is generally a constant value. Based on the PIN photoelectric tube trigger signal 9, the control circuit 6 generates a laser pulse trigger signal 10 with a delay of t2, which is used to trigger the laser emission module to emit a laser pulse. The moment the laser pulse is emitted is the moment laser pulse signal 11 is generated. A fixed delay t3 occurs between laser pulse trigger signal 10 and laser pulse signal 11. This delay t3 is determined by the laser emission module and is generally a fixed value. Laser pulse signal 11 is the starting point of laser ranging timing. The time from laser pulse signal 11 to the edge of the APD detector's light-sensitive surface 13 entering the APD light-passing area 7 of the shielding turntable is t4, which is the short-range blind zone of ranging. During this time, the APD detector 3 is blocked, and the short-range scattered light of the laser pulse and the target's return signal cannot enter the detector, completely eliminating the impact of short-range scattered light on the APD detector 3. Using laser pulse signal 11 as the starting point of laser ranging timing, after time t5, the APD detector 3 receives the target return signal 12. The target distance is then ct5 / 2, where c is the speed of light. The rotation angle θ2 corresponding to the APD light-passing area 7 of the shielding disk must ensure that the time it takes for the light-passing area to pass through the APD detector's photosensitive surface 13 is greater than the maximum range of the laser rangefinder, that is, θ2 > 2Lω / c, where L is the maximum range of the laser rangefinder. One rotation of the shielding disk completes a distance measurement. The control circuit 6 can adjust the distance of the short-range blind zone by setting the value of t2 to compensate for errors caused by the high-speed motor speed and the shielding disk's position accuracy.

[0028] Example 2: Figure 4 and Figure 5As shown, the pulse laser rangefinder receiving assembly capable of eliminating short-range scattering of this embodiment includes a shielding turntable 1, a high-speed motor 2, an APD detector 3, a PIN phototube 4, an LED 5, and a control circuit 6. The high-speed motor 2 is connected to the center of the shielding turntable 1 and drives the shielding turntable 1 to rotate at a high and uniform speed. The APD detector 3 is located on one side of the shielding turntable 1 and is close to the edge. The target reflected echo passes through the shielding turntable 1 from the other side of the shielding turntable 1 and enters the APD detector 3; the PIN phototube 4 is located on one side of the shielding turntable 1, near the APD detector 3, and is close to the edge. The LED 5 is located on the other side of the shielding turntable 1, and the light it emits passes through the shielding turntable 1 from the other side of the shielding turntable 1. The turntable 1 can enter the PIN phototube 4, and the LED 5 is always on. When the blocking area of ​​the shielding turntable 1 is between the LED 5 and the PIN phototube's photosensitive surface 14, the PIN phototube 4 cannot receive the light signal from the LED 5. When the shielding turntable PIN light hole 8 passes between the LED 5 and the PIN phototube's photosensitive surface 14 at high speed, the PIN phototube 4 briefly receives a pulsed light signal from the LED 5. This signal is the PIN phototube trigger signal 9. At this time, the APD detector's photosensitive surface 13 is blocked, and the angle from the start of the shielding turntable's APD light-passing area 7 is θ1. The corresponding transit time is t1 = θ1 / ω. t1 is determined by the positional relationship between the shielding area and the light-passing area on the shielding turntable 1 and the speed of the shielding turntable 1 and is generally a constant value. Based on the PIN photoelectric tube trigger signal 9, the control circuit 6 generates a laser pulse trigger signal 10 with a delay of t2, which is used to trigger the laser emission module to emit a laser pulse. The moment the laser pulse is emitted is the moment laser pulse signal 11 is generated. A fixed delay t3 occurs between laser pulse trigger signal 10 and laser pulse signal 11. This delay is determined by the laser emission module and is generally a fixed value. Laser pulse signal 11 is the starting point of laser ranging timing. The time from laser pulse signal 11 to the edge of the APD detector's light-sensitive surface 13 entering the APD light-passing area 7 of the shielding turntable is t4, which is the short-range blind zone of ranging. During this time, the APD detector 3 is blocked, and the short-range scattered light of the laser pulse and the target's return signal cannot enter the detector, completely eliminating the impact of short-range scattered light on the APD detector 3. Using laser pulse signal 11 as the starting point of laser ranging timing, after time t5, the APD detector 3 receives the target return signal 12. The target distance is then ct5 / 2, where c is the speed of light. The rotation angle θ2 corresponding to the APD light-passing area 7 of the shielding turntable must ensure that the time it takes for the light-passing area to pass through the APD detector photosensitive surface 13 is greater than the maximum range of the laser rangefinder, that is, θ2>2Lω / c, where L is the maximum range of the laser rangefinder.There are n groups of shielding turntable APD light-transmitting areas 7 and shielding turntable PIN light-transmitting holes 8 on the shielding turntable 1, and they are rotationally symmetrically distributed on the shielding turntable 1. The rotation angle occupied by each group is 2π / n. The shielding turntable 1 can complete n ranging processes in one rotation. The distance of the short-range blind area can be adjusted by setting the value of t2 by the control circuit 6 to compensate for the errors caused by the high-speed motor speed and the shielding turntable position accuracy.

[0029] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0030] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A pulse laser rangefinder receiving component capable of eliminating short-range scattering, characterized in that: include: A shielding turntable (1), a high-speed motor (2), an APD detector (3), a PIN phototube (4), an LED (5), and a control circuit (6); The high-speed motor (2) is connected to the center of the shielding turntable (1) and drives the shielding turntable (1) to rotate at a high and uniform speed. The APD detector (3) is located on one side of the shielding turntable (1) and is close to the edge of the shielding turntable (1). The target reflection echo passes through the shielding turntable (1) from the other side of the shielding turntable (1) and enters the APD detector (3), generating a ranging laser echo signal. The PIN phototube (4) is located on the same side of the shielding turntable (1) as the APD detector (3) and is close to the edge of the shielding turntable (1). The LED light emitting diode (5) is located on the other side of the shielding turntable (1). The light emitted by the LED light emitting diode (5) passes through the shielding turntable (1) from the other side of the shielding turntable (1) and enters the PIN phototube (4), generating a PIN phototube trigger signal. The control circuit (6) drives the high-speed motor (2) to rotate and receives the ranging laser echo signal generated by the APD detector (3) and the PIN phototube trigger signal generated by the PIN phototube (4). The control circuit (6) processes the received ranging laser echo signal and the PIN phototube trigger signal to send a trigger signal to trigger the laser emission module to emit a laser pulse; The shielding turntable (1) is provided with a shielding turntable APD light-transmitting area (7) and a shielding turntable PIN light-transmitting hole (8). The shielding turntable (1) is circular, and the center of the shielding turntable (1) is connected to the rotating shaft of the high-speed motor (2). The shielding turntable (1) rotates at a high speed with the center of the circle as the axis. The areas on the shielding turntable (1) other than the shielding turntable APD light-transmitting area (7) and the shielding turntable PIN light-transmitting hole (8) are all shielding areas. The shielding area on the shielding turntable (1) needs to pass through the APD detector photosensitive surface at a high speed. The corresponding rotation angle of the shielding turntable APD light-transmitting area (7) is It is necessary to ensure that the time it takes for the light-passing area to pass through the photosensitive surface (13) of the APD detector is greater than the maximum range of the laser rangefinder, that is, , where c is the speed of light, is the rotation speed of the high-speed motor (2), and L is the maximum measuring range of the laser rangefinder.

2. The pulse laser rangefinder receiving component according to claim 1, characterized in that: The length of the shielding area on the shielding turntable (1) across the photosensitive surface of the APD detector and the size of the photosensitive surface of the APD detector satisfy: ,in, is the diameter of the APD detector photosensitive surface, R is the distance between the photosensitive surface of the APD detector and the center of the shielding turntable (1), is the blind zone time of the laser rangefinder.

3. The pulse laser rangefinder receiving component according to claim 1 or 2, characterized in that: The LED (5) is in a constantly lit state. When the shielding area of ​​the shielding turntable (1) is between the LED (5) and the PIN phototube light-sensitive surface (14), the PIN phototube (4) cannot receive the light signal of the LED (5). When the shielding turntable PIN light-through hole (8) passes between the LED (5) and the PIN phototube light-sensitive surface (14) at high speed, the PIN phototube (4) briefly receives the pulse light signal of the LED (5). The pulse light signal is the PIN phototube trigger signal (9). At this time, the APD detector light-sensitive surface (13) is in a shielded state, and the angle from the starting point of the shielding turntable APD light-through area (7) is , the corresponding passing time is The control circuit (6) generates a delay of The laser pulse trigger signal (10) is used to trigger the laser emission module to emit a laser pulse. The laser pulse is emitted at the same time as the laser pulse signal (11) is generated. A fixed delay is generated between the laser pulse trigger signal (10) and the laser pulse signal (11). The laser pulse signal (11) is the starting point of the laser ranging timing. The time from the laser pulse signal (11) to the APD detector photosensitive surface (13) entering the edge of the APD light-passing area (7) of the shielding turntable is , which is the short-range blind area of ​​ranging. During the time, the APD detector (3) is blocked, and the short-range scattering of the laser pulse and the echo signal of the target cannot enter the APD detector (3). The influence of the short-range scattered light on the APD detector (3) is completely eliminated. The laser pulse signal (11) is used as the starting point of the laser ranging timing. After the time After the APD detector (3) receives the target echo signal (12), the target distance value is .

4. The pulse laser rangefinder receiving component according to claim 3, characterized in that: The PIN photoelectric tube (4) and the APD detector (3) are respectively located at two opposite edges of the shielding turntable (1).

5. The pulse laser rangefinder receiving component according to claim 3, characterized in that: The PIN phototube (4) and the APD detector (3) are located on the same edge of the shielding turntable (1).

6. The pulse laser rangefinder receiving component according to claim 4 or 5, characterized in that: The shielding turntable (1) has n groups of shielding turntable APD light-transmitting areas (7) and shielding turntable PIN light-transmitting holes (8), which are rotationally symmetrically distributed on the shielding turntable (1), and the rotation angle occupied by each group is The shielding turntable (1) completes n distance measurement processes in one rotation, where n is a positive integer.

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