Retro-reflection measuring device

Abstract

The utility model provides a retro-reflection measuring device which comprises a shading unit, a directional light source and an array detector are arranged in the shading unit, a sample to be measured is arranged on a sample table in the shading unit or located outside the shading unit, and light beams emitted from the directional light source irradiate the sample to be measured in a directional mode. The array detector is arranged on the retro-reflection light path and receives retro-reflection light beams of the detected sample. According to the utility model, the array detector arranged on the retro-reflection light path is used for efficiently receiving the retro-reflection light beam of the measured sample, so that the retro-reflection characteristic of the measured sample at a specific angle is measured, and the device has the characteristics of simple light path, high measurement accuracy, high measurement speed, convenience in operation, low cost and the like; and the measurement requirements of a plurality of occasions such as laboratories, industrial production lines and on-site rapid testing can be met.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of retro reflection measurement, and specifically relates to a retro reflection measurement device. BACKGROUND

[0002] Materials with good reflection characteristics, especially good retro reflection characteristics, are widely used in automobiles, motor vehicles, warning signs and other occasions, and play a very key role in road traffic and personal safety. Reflection characteristics or retro reflection characteristics are key technical indicators of such materials, and effective measurement thereof is of great significance. Since the measurement of the retro reflection characteristics of materials must be performed in the direction where the incident and received light paths coincide or are very close, the technical difficulty is extremely great, and so far no effective device or method suitable for measuring the optical characteristics of retro reflectors or materials has been found.

[0003] The traditional retro reflection measurement light path is shown in Figure 1 A standard A light source illuminates the measured sample at a certain illumination angle, and a light detector receives the retro reflection light emitted by the measured sample at a certain observation angle (i.e. the included angle between the illumination axis and the observation axis), thereby achieving the measurement of the photometric characteristics of the retro reflection material or retro reflector. Generally, the observation angle is mostly 2° or less, so the optical path of the illumination light path and the reflection light path is relatively long, and the optical signal of the retro reflection light reaching the detector is very weak, making it difficult to achieve the spectral characteristic measurement of the material; and the above-mentioned retro reflection measurement needs to be performed in a very large darkroom space, which is only suitable for laboratory photometric measurement requirements and cannot meet the requirements of industrial production lines and on-site rapid testing. UTILITY MODEL CONTENT

[0004] In view of the deficiencies of the prior art, the utility model provides a retro reflection measurement device, which can quickly and efficiently achieve accurate measurement of the optical characteristics of retro reflection materials under the condition that the incident light and the reflected light are close to opposite directions.

[0005] To achieve the above technical purpose, the utility model adopts the following technical scheme:

[0006] The utility model provides a retro reflection measurement device, which comprises a light shielding unit, a directional light source and an array detector are arranged in the light shielding unit, a measured sample is arranged on a sample table in the light shielding unit or the measured sample is located outside the light shielding unit, a light beam emitted by the directional light source is directed to irradiate the measured sample, and the array detector is arranged on a retro reflection light path to receive the retro reflection light beam of the measured sample.

[0007] In the above technical solution, by setting the directional light source in the light shielding unit, the light beam emitted by the light source is accurately irradiated to the measured sample in a specific direction, thereby accurately exciting the retroreflection phenomenon of the measured sample, and the array detector arranged on the retroreflection light path efficiently receives the retroreflection light beam of the measured sample. The detection units of the array detector in the utility model are arranged in one-dimensional linear array or two-dimensional surface array, such as CMOS or CCD or diode array, the size of a single pixel can reach microns, and the measurement values of multiple pixels can be mutually accumulated and calculated (also known as macro mode). The high-resolution pixel distribution of the array detector in the utility model can more accurately capture the slight change of the angle, and since each pixel corresponds to a relatively small observation angle range, this provides the possibility for accurately measuring the retroreflection characteristics under the slight observation angle, which is of great significance for studying the optical response characteristics of the retroreflective material.

[0008] In a specific embodiment, the array detector can be arranged beside or behind the directional light source, and the array detector is two or more single-channel detectors or two-dimensional array multi-channel detectors, or a combination of multi-channel detectors and two-dimensional array multi-channel detectors. As a preferred, the array detector adopts refrigeration technology, which can significantly suppress thermal noise, has high pixel resolution, can capture weak signals, improve measurement accuracy and resolution, and directly receive the retroreflection light from the measured sample through the pixel of the array detector. The observation angle formed by the detection surface of the array detector relative to the measured sample and the directional light source can be controlled to a very small angle through the small pixel unit of the array detector, without the need for a long distance, and the measurement of the retroreflection light distribution is also very fine. The pixel coordinates of the array detector can be corresponded to the observation angle of the retroreflection, and the pixel response value of the array detector can be corresponded to the retroreflection light intensity. Further, the other retroreflection parameters of the measured sample under the specified observation angle can be derived and calculated according to the retroreflection light intensity, such as the retroreflection light intensity coefficient, the retroreflection coefficient, and the retroreflection brightness coefficient. The light shielding unit can be a light shielding shell, and can also be a light measurement darkroom, which is suitable for different measurement scene requirements such as laboratory, industrial production line, and field measurement.

[0009] Further, a light blocking component is arranged between the array detector and the directional light source to block the light beam emitted by the directional light source from directly entering the array detector, so as to further guarantee the accuracy of the measurement result and avoid the influence of stray light. Because the light emitted by the light source is irradiated on the measured sample, a part of the light may directly enter the array detector without the light blocking component, thereby affecting the measurement result and increasing the measurement error. The light blocking component and the light source can be designed in an integrated manner, such as a directional LED lamp, and the light blocking component is an optical reflector in the lamp, so that the light beam emitted by the light source is concentrated on the measured sample; or the light blocking component and the light source are two independent structures separated from each other, such as a reflector that reflects the light emitted by the light source and different from the direction of the measured sample, so as to avoid the light from directly entering the array detector.

[0010] As a technical solution, a hole mirror is arranged in front of the directional light source, the hole mirror is located in the light path from the directional light source to the measured sample, and the hole mirror is also located in the light path from the measured sample to the array detector; the light beam emitted by the directional light source passes through the hole mirror, and the returned reflection light beam emitted by the measured sample enters the array detector after being reflected by the hole mirror. In the technical solution, the light path layout is optimized by the design of the hole mirror, so that the entire returned reflection measurement device is more simple and compact in structure, which is beneficial to the miniaturization and integration of the device, and facilitates the installation and use in different scenes; by turning the observation light path through the hole mirror, compared with the traditional long-distance measurement, the influence of external factors and the loss of light are reduced, and the stability, reliability and accuracy of the measurement are improved. The hole mirror corresponds to a measurement ring corresponding to a certain observation angle, so that the array detector can complete the returned reflection measurement at the specified observation angle by receiving the ring light signal of the returned reflection light of the measured sample. In addition, the reflection path of the light can be flexibly changed by adjusting the angle or position of the hole mirror, so as to realize the collection of returned reflection light in different directions, and provide the possibility for multi-angle measurement of the returned reflection characteristics of the measured sample. The light path design of the utility model is simple and ingenious, and no supporting device is needed, complete returned reflection ring light signals can be obtained, the measurement accuracy is high, and the stability is good; the light path has strong expansibility, the hole mirror that meets a certain observation angle can be set according to the test requirement, and the returned reflection characteristic measurement of the ring light signal at the specified observation angle is completed; in addition, the irradiation light path from the directional light source to the measured sample and the measurement light path from the measured sample to the array detector are not interfered with each other by the ingenious arrangement of the light path, and the measurement purpose can be realized only by starting the directional light source, which has the characteristics of low cost, low stray light and convenient operation.

[0011] As a technical solution, the device further comprises a diffusing screen located in the reflected light path of the aperture mirror, the array detector is located in an imaging measurement unit, and the imaging measurement unit further comprises an imaging lens, and the imaging measurement unit is arranged to face the diffusing screen, wherein the imaging lens images the light spot image on the diffusing screen into the array detector. The use of the diffusing screen widens the effective receiving range of the device for the returned reflected light, helps to obtain more comprehensive returned reflected light distribution data, and reduces measurement errors. In addition, since the diffusing screen uniformly diffuses light, even if there is a certain small deviation in the position of the array detector in the imaging measurement unit, the diffused light spot image can be relatively uniformly received. This reduces the stringent requirements for the installation position accuracy of the array detector, simplifies the assembly process of the device, and improves the stability and reliability of the device in actual use.

[0012] As a technical solution, one or more mirrors are further arranged in the light path between the aperture mirror and the measured sample, and the mirror is a plane mirror or a concave mirror or a convex mirror. The light beam emitted from the directional light source enters the measured sample after passing through the aperture of the aperture mirror and the one or more mirrors in turn. The returned reflected light after being affected by the measured sample passes through the one or more mirrors and then passes through the aperture mirror to finally enter the array detector. By folding the light path with one or more mirrors, the layout of the light path is optimized, interference between the light path and other components is avoided, the internal space of the device is effectively saved, the structure of the entire returned reflected measurement device is more compact and reasonable, the miniaturization design and integrated assembly of the equipment are facilitated, and the requirements of different application scenarios such as field measurement and industrial production line for the volume of the device are met. By turning the observation light path with one or more mirrors, the optical path is accurately controlled, compared with traditional long-distance measurement, the influence of external factors and the loss of light are reduced, and the stability, reliability and accuracy of the measurement are improved.

[0013] As a technical solution, one or more mirrors are further arranged in the light path between the aperture mirror and the array detector, and the mirror is a plane mirror. By arranging one or more mirrors in the light path between the aperture mirror and the array detector, the light path is flexibly adjusted, the optical path is increased, the layout of the entire optical system is optimized, the detection sensitivity is improved, the space is effectively saved, and the structure of the entire returned reflected measurement device is more compact and reasonable, facilitating the miniaturization design and integrated assembly of the equipment.

[0014] As a technical solution, the light shielding unit is a light shielding cylinder, and the measured sample is located outside the light shielding unit. The inner surface of the light shielding cylinder is a matt black color. A sampling port is arranged at one end of the light shielding cylinder. The measured sample is irradiated by the directional light source through the sampling port and the back reflection light beam is recovered. The inner surface of the light shielding cylinder is matt black, which can effectively absorb stray light and prevent external environmental light from interfering, thereby ensuring the stability and reliability of the measurement results. At the same time, the light shielding cylinder can be easily integrated with optical elements and devices such as directional light sources and array detectors, thereby realizing miniaturized design. The entire device is enclosed in a relatively small space, so that the entire measurement process does not need to be configured with an optical darkroom, thereby greatly reducing the laboratory construction cost. The device is small in size, easy to operate, portable and movable, and can meet the measurement requirements of various occasions such as industrial production lines and on-site rapid testing, thereby improving the flexibility and efficiency of measurement. The sampling port provides a clear placement position for the measured sample, so that the position and angle of the sample can be kept relatively consistent during each measurement, and the measured sample can be accurately positioned. When batch testing small samples, the samples can be accurately placed at the sampling port, so that each sample can be detected under the same lighting and measurement conditions, thereby avoiding measurement deviation caused by sample position difference. At the same time, the sample can be easily replaced, and the operator can quickly place the new sample in place for measurement without complex installation and adjustment process, thereby improving the efficiency of measurement.

[0015] As a further improvement of the above technical solution, a sample interface is further included. One side of the sample interface is connected with the sampling port, and the measured sample is placed on the other side of the sample interface. The sample interface is used to accurately place the sample, so that the sample can be placed at the same measurement position every time. When continuously measuring multiple similar samples, the accurate positioning of the sample interface can avoid measurement errors caused by position deviation, so that the measurement data is more reliable and comparable. In one specific embodiment, the sample interface includes two or more sample interfaces, and each sample interface is arranged such that the normal line of the measured sample and the beam axis of the directional light source form a fixed angle, such as 0.2°, 0.33° or 0.5°. Different sample interfaces are used to realize measurement at different observation angles, which can meet the measurement requirements of different types of samples and greatly enhance the flexibility and adaptability of measurement.

[0016] As a further improvement of the above technical solution, an angle adjusting mechanism for changing the angle between the optical axis of the light beam of the light source and the normal line of the measured sample, a base and a support are further included, the lower end of the support is fixedly connected with the base, the lower end of the light shielding shell is rotatably provided with the angle adjusting mechanism, and the angle adjusting mechanism is rotatably connected with the upper end of the support. The angle between the normal line of the measured sample and the optical axis of the directional light source is changed through the angle adjusting mechanism, the observation angle is changed, continuous or more fine angle adjustment is realized, the operator can obtain more comprehensive and accurate measurement data according to the actual measurement requirements, and the measurement of different types of samples is also applicable, the operation process is simplified, compared with the traditional way of changing the observation angle by installing the measured sample on a rotating table, the angle adjusting mechanism can realize the angle adjustment only by simple operation, the work efficiency is improved, and the equipment cost is reduced.

[0017] As another technical solution, the light shielding unit is a light measurement darkroom, a rotating table is arranged in the light measurement darkroom, and the measured sample is arranged on the rotating table. The illumination angle between the optical axis of the light beam of the directional light source and the normal line of the measured sample is changed through the rotating table, and then the measurement of the retroreflective characteristic of the measured sample under a specific incident angle is realized. The technical solution is applicable to laboratory measurement.

[0018] As another technical solution, the light shielding unit is a light measurement darkroom, a rotating table is arranged in the light measurement darkroom, and the measured sample is arranged on the rotating table; a diffusion screen is arranged beside the directional light source, the diffusion screen faces the measured sample on the rotating table, the array detector is located in an imaging measurement unit, and the imaging measurement unit further includes an imaging lens, and the imaging measurement unit faces the diffusion screen, wherein the imaging lens images the light spot image on the diffusion screen into the array detector, and the fast and accurate measurement of the retroreflective characteristic of the measured sample is realized.

[0019] As a technical solution, a light blocking component is arranged between the diffusion screen and the directional light source, for blocking the light beam emitted by the directional light source from directly entering the diffusion screen; the measurement field of view of the imaging measurement unit avoids the light beam of the directional light source, and only the light spot information on the diffusion screen is collected. Through the design of the light blocking component, the influence of stray light is avoided, and the accuracy of the measurement result is ensured.

[0020] As a technical solution, a standard light source with known light intensity distribution and used for calibrating the response of the array detector is included. Before actual measurement, the response of the array detector is calibrated through the standard light source with known light intensity distribution, the standard light source is placed at the position where the measured sample is placed, the standard light source is reversely irradiated to form a response on the array detector, the response value of the pixel on the array detector is calibrated according to the known light intensity value, the pixel response error is effectively corrected, and the accuracy and consistency of the measurement are further improved. The calibrated array detector is used to measure the retroreflective optical characteristic of the measured sample, and the obtained measurement result is more accurate.

[0021] As a technical solution, one or more stray light elimination diaphragms are arranged in the light shielding unit. The stray light elimination diaphragm is arranged on the illumination light path between the light source and the measured sample, or on the return reflection observation light path between the measured sample and the array detector. By arranging the stray light elimination diaphragm, the interference of external light on the observation light path and the illumination light path is prevented, the stray light is reduced, and the measurement accuracy is improved.

[0022] As a technical solution, the directional light source adopts a halogen tungsten lamp, a high-intensity gas discharge lamp, an LED lamp or a laser, or a combination of two or more types of light sources. The light source is built-in to collimate the light, so that the return reflection parameters of the measured sample can be accurately measured, and the accuracy of the measurement results is ensured.

[0023] As a technical solution, the light source includes one or more programmable driving different monochromatic LEDs, and the one or more monochromatic LEDs emit light independently or in combination. The light source in the utility model has multiple implementation manners, which can include an LED array of multiple different monochromatic LEDs. By controlling the multiple different monochromatic LEDs on the LED array to emit light independently or in combination, the return reflection characteristics of the measured sample under different illumination light sources can be measured by directly irradiating the measured sample. The light source can also include an integrating sphere. The light emitted by the one or more monochromatic LEDs independently or in combination is mixed by the integrating sphere and then irradiates the measured sample. The multiple different monochromatic LEDs can also cooperate with the integrating sphere. Since the beam angle of the light emitted by the LED is relatively narrow, the uniformity of the light intensity emitted by the light source cannot be guaranteed, especially for the direct mixing of multiple monochromatic LEDs. The direct mixing effect is poor. By arranging the multiple different monochromatic LEDs on the integrating sphere, the light emitted by the multiple different monochromatic LEDs independently or in combination is mixed by the integrating sphere and then irradiates the measured sample. This indirect irradiation method can ensure that the irradiation light received by the measured sample is uniform, and avoid measurement errors caused by non-uniform irradiation light. In addition, other light sources used in other return reflection measurement devices can also be used in the utility model. The monochromatic LED driving mode can also be flexibly selected. Preferably, a pulse driving mode is adopted. By using the phase-locked amplification technology, stray light can be effectively removed, the measurement accuracy can be improved, the subsequent signal processing is simpler, and the test efficiency is improved. In real life, for example, in the case of roads, the early car lights are mostly halogen lamps similar to standard A light sources, so the return reflection measurement in the related standards is based on A light sources. However, the current car lights are very rich, including xenon headlights, LED headlights, laser headlights, etc., and their spectral components also differ, so it is necessary to measure the return reflection characteristics of the measured sample under different illumination light source spectra. The technical solution can conveniently realize this measurement.

[0024] The utility model discloses a beneficial effect: the utility model provides a kind of reply reflection measuring device, by being provided with directional light source in shading unit, the light beam emitted by light source is accurately irradiated to measured sample with specific direction, and further accurately excite the reply reflection phenomenon of measured sample, by the array detector of being set on reply reflection light path, the reply reflection light beam of measured sample is received efficiently, and further realize the measurement of the reply reflection characteristic of measured sample under specific angle, with simple light path, measurement accuracy is high, measurement speed is fast, it is easy to operate and with low cost and the characteristics such as cost, can satisfy laboratory, industrial production line and the measurement demand of many occasions such as on-site rapid test. BRIEF DESCRIPTION OF DRAWINGS

[0025] ATTACH Figure 1 It is the schematic diagram of existing reply reflection measurement light path;

[0026] ATTACH Figure 2 It is the structure schematic diagram of reply reflection measuring device of embodiment 1;

[0027] ATTACH Figure 3 It is the structure schematic diagram of reply reflection measuring device of embodiment 2;

[0028] ATTACH Figure 4 It is the structure schematic diagram of reply reflection measuring device of embodiment 3;

[0029] ATTACH Figure 5 It is the structure schematic diagram of reply reflection measuring device of embodiment 4;

[0030] ATTACH Figure 6 It is the structure schematic diagram of reply reflection measuring device of embodiment 5;

[0031] ATTACH Figure 7 It is the structure schematic diagram of reply reflection measuring device of embodiment 6;

[0032] ATTACH Figure 8 It is the structure schematic diagram of reply reflection measuring device of embodiment 7;

[0033] In the drawing, 1-shading unit, 2-directional light source, 3-array detector, 4-measured sample, 5-hole mirror, 6-diffusion screen, 7-imaging measurement unit, 8-mirror, 9-sample interface, 10- stray light stop, 11-rotary table, 12-sampling port. DETAILED DESCRIPTION Embodiment one

[0034] The embodiment discloses a kind of reply reflection measuring device, as Figure 2As shown, the device comprises a light shielding unit 1 and a sample stage, a directional light source 2 and an array detector 3 are arranged in the light shielding unit 1, a measured sample 4 is arranged on the sample stage outside the light shielding unit 1, a light beam emitted from the directional light source 2 is directed to irradiate the measured sample 4, the array detector 3 is arranged beside or behind the directional light source 2 to directly receive the returned reflection light beam of the measured sample 4. The sample stage is a rotating stage 11, the rotating stage 11 drives the change of the illumination angle between the optical axis of the light beam of the directional light source 2 and the normal line of the measured sample, thereby realizing the measurement of the returned reflection characteristics of the measured sample at a specific incident angle. The light shielding unit 1 is a light shielding cylinder, the inner surface of the light shielding cylinder is matt black, a sampling port 12 is arranged at one end of the light shielding cylinder, the measured sample 4 is irradiated by the directional light source 2 through the sampling port 12 and the returned reflection light beam is received by the array detector for measurement. The directional light source 2 adopts laser, the array detector 3 is a two-dimensional area array detector, and a refrigeration technology is adopted. The device is suitable for laboratory, industrial production line and on-site measurement. Preferably, a standard light source with known light intensity distribution and used for calibrating the response of the array detector is further included. Before actual measurement, the response of the array detector is calibrated in advance by the standard light source with known light intensity distribution. The standard light source is placed at the position where the measured sample is placed, the standard light source is reversely irradiated to form a response on the array detector, the response value of the pixel on the array detector is calibrated according to the known light intensity value, the pixel response error is effectively corrected, and the accuracy and consistency of the measurement are further improved. Further, the corresponding relationship between the pixel of the array detector and the observation angle is calibrated through the spatial geometric position relationship; or a collimated light source is used to reversely irradiate at one or more angles at the position of the measured sample, the angle between the optical axis of the light beam of the collimated light source and the optical axis of the light beam of the directional light source irradiating the sample is known, the corresponding relationship between the pixel position and the observation angle is calibrated according to the pixel response of the array detector, the calibrated array detector is used to measure the returned reflection optical characteristics of the measured sample, and the obtained measurement result is more accurate. Embodiment two

[0035] The embodiment discloses a returned reflection measurement device, which comprises a light shielding unit 1 and a sample stage, Figure 3As shown, the system includes a light-shielding unit 1 and a sample stage. A directional light source 2, a perforated mirror 5, and an array detector 3 are disposed within the light-shielding unit 1. The sample 4 to be tested is located outside the light-shielding unit 1 and is placed on the sample stage. The perforated mirror 5 is positioned in front of the directional light source 2, in the optical path from the directional light source 2 to the sample 4, and also in the optical path from the sample 4 to the array detector 3. The light beam emitted from the directional light source 2 passes through the perforated mirror 5, and the reflected light beam emitted from the sample 4 is reflected by the perforated mirror 5 before entering the array detector 3. The sample stage is a rotating stage 11. The rotating stage 11 changes the illumination angle formed between the optical axis of the directional light source 2 and the normal of the sample, thereby enabling the measurement of the reflected light characteristics of the sample at a specific incident angle. The light-shielding unit 1 is a light-shielding cylinder with a matte black inner surface. A sampling port 12 is provided at one end of the light-shielding cylinder. The sample 4 is illuminated by the directional light source 2 through the sampling port 12 and reflects the light back. In this embodiment, the array detector is a ring array detector, which adopts cooling technology. The directional light source includes one or more programmable monochromatic LEDs of different colors. The one or more monochromatic LEDs emit light independently or in combination. This device is suitable for rapid on-site measurement in industrial production lines. Example 3

[0036] This embodiment discloses a retroreflection measurement device, such as... Figure 4 As shown, the system includes a light-shielding unit 1 and a sample stage. Within the light-shielding unit 1, a directional light source 2, a perforated mirror 5, multiple plane mirrors 8, and an array detector 3 are arranged. The sample 4 to be tested is located outside the light-shielding unit 1 and placed on the sample stage. The perforated mirror 5 is positioned in front of the directional light source 2, in the optical path from the directional light source 2 to the sample 4, and also in the optical path from the sample 4 to the array detector 3. Two additional plane mirrors 8 are also arranged in the optical path between the perforated mirror 5 and the sample 4, and one additional plane mirror 8 is arranged in the optical path between the perforated mirror 5 and the array detector 3. The light beam emitted from the directional light source 2 passes sequentially through the small hole in the perforated mirror 5 and the reflected light path of one or more mirrors before entering the sample 4. The reflected light from the sample 4 passes through one or more mirrors 8 and is reflected again by the perforated mirror 5 before finally entering the array detector 3. The array detector 3 is a two-dimensional planar array detector employing cooling technology. The sample stage is a rotary stage 11. The rotary stage 11 changes the illumination angle between the optical axis of the directional light source 2 and the normal to the sample under test, thereby enabling the measurement of the retroreflection characteristics of the sample at a specific incident angle. The light-shielding unit 1 is a light-shielding cylinder with a matte black inner surface. A sampling port 12 is located at one end of the light-shielding cylinder. The sample under test 4 is illuminated by the directional light source 2 through the sampling port 12 and reflects the backlight beam. This device is suitable for rapid on-site measurements in industrial production lines. Example 4

[0037] This embodiment discloses a retroreflection measurement device, such as... Figure 5 As shown, the device includes a light-shielding unit 1 and a sample interface 9. The light-shielding unit 1 contains a directional light source 2, a perforated reflector 5, multiple planar reflectors 8, and an array detector 3. The light-shielding unit 1 is a light-shielding tube with a matte black inner surface. A sampling port 12 is located at one end of the light-shielding tube. One side of the sample interface 9 is connected to the sampling port 12, and the sample to be tested 4 is placed on the other side of the sample interface 9. The sample interface 9 includes two or more sample interfaces 9, and each sample interface 9 sets the normal of the sample to be tested at a different angle to the beam axis of the directional light source 2. A perforated reflector 5 is placed in front of the directional light source 2. The perforated reflector 5 is located in the optical path from the directional light source 2 to the sample 4 under test, and also in the optical path from the sample 4 under test to the array detector 3. Two reflectors 8 are also placed in the optical path between the perforated reflector 5 and the sample 4 under test, and one reflector 8 is placed in the optical path between the perforated reflector 5 and the array detector 3. The reflectors 8 are plane mirrors. The light beam emitted from the directional light source 2 passes sequentially through the small hole of the perforated reflector 5 and the optical path refracted by one or more reflectors before entering the sample 4 under test. The reflected light from the sample 4 passes through one or more reflectors 8 and is reflected again by the perforated reflector 5 before finally entering the array detector 3, thereby realizing the measurement of the reflected light characteristics of the sample under test at a specific incident angle. The directional light source 2 is a halogen tungsten lamp, a high-intensity gas discharge lamp, an LED lamp, or a laser, or a combination of two or more of the above types of light sources. Example 5

[0038] This embodiment discloses a retroreflection measurement device, such as... Figure 6As shown, it includes a light-shielding unit 1 and a sample stage. Inside the light-shielding unit 1, there is a directional light source 2, a perforated reflector 5, multiple plane reflectors 8, a diffuser 6, a stray light elimination aperture 10, and an imaging measurement unit 7. The sample 4 to be measured is located outside the light-shielding unit 1 and is placed on the sample stage. A perforated reflector 5 is placed in front of the directional light source 2. The perforated reflector 5 is located in the optical path from the directional light source 2 to the sample 4 under test, and also in the optical path from the sample 4 under test to the imaging measurement unit 7. Two reflectors 8 are also placed in the optical path between the perforated reflector 5 and the sample 4 under test, and one reflector 8 is placed in the optical path between the perforated reflector 5 and the array detector 3. The reflectors 8 are plane mirrors. The diffuser screen 6 is located in the reflected optical path of the perforated reflector 5. The light beam emitted from the directional light source 2 passes through the small hole of the perforated reflector 5 and the reflected optical path of one or more reflectors in sequence before entering the sample 4 under test. The reflected light from the sample 4 under test passes through one or more reflectors 8 and is reflected by the perforated reflector 5 before finally entering the diffuser screen. The array detector 3 is a two-dimensional area array detector located in an imaging measurement unit 7. The imaging measurement unit 7 also includes an imaging lens. The imaging measurement unit 7 is set facing the diffuser screen 6, and the imaging lens images the light spot image on the diffuser screen 6 into the array detector 3. An anti-stray light aperture 10 is provided in front of the imaging measurement unit 7. The sample stage is a rotary stage 11. The rotary stage 11 drives the change of the illumination angle formed between the optical axis of the directional light source 2 and the normal of the sample under test, thereby realizing the measurement of the retroreflection characteristics of the sample under test at a specific incident angle. Example 6

[0039] This embodiment discloses a retroreflection measurement device, such as... Figure 7 As shown, the device includes a light-shielding unit 1, which is a photometric darkroom. Inside the darkroom, a rotating stage 11, a directional light source 2, a diffuser screen 6, a stray light elimination aperture 10, and an imaging measurement unit 7 are arranged. The sample 4 to be tested is placed on the rotating stage 11. The diffuser screen 6 is positioned beside the directional light source 2, facing the sample 4 on the rotating stage 11. The array detector 3 is located within the imaging measurement unit 7, which also includes an imaging lens. The imaging measurement unit 7 faces the diffuser screen 6. The light beam emitted from the directional light source 2 is directed onto the sample 4 through the stray light elimination aperture 10. The retroreflected light from the sample 4 is projected onto the diffuser screen 6, forming a light spot. The imaging lens images the light spot image on the diffuser screen 6 onto the array detector 3, thereby achieving the measurement of the retroreflection characteristics of the sample at a specific incident angle. This device is suitable for laboratory measurements. Example 7

[0040] This embodiment discloses a retroreflection measurement device, such as... Figure 8As shown, the device comprises a light shielding unit 1, which is a light measurement darkroom, wherein a rotating table 11, a directional light source 2, a diffusion screen 6, a hole mirror 5 and an imaging measurement unit 7 are arranged. A sample 4 to be measured is arranged on the rotating table 11, and a hole mirror 5 is arranged in front of the directional light source 2, which is located in the light path from the directional light source 2 to the sample 4 to be measured, and also located in the light path from the sample 4 to be measured to the diffusion screen 6; the light beam emitted by the directional light source 2 is incident on the sample 4 to be measured through the small hole of the hole mirror 5, and the returned reflection light beam emitted by the sample 4 to be measured is incident on the diffusion screen 6 after being reflected by the hole mirror 5; the imaging measurement unit 7 is arranged facing the diffusion screen 6, and comprises an imaging lens and an array detector; the imaging lens images the light spot image on the diffusion screen 6 into the array detector 3, thereby realizing the measurement of the returned reflection characteristics of the sample to be measured. The device is suitable for laboratory measurement.

[0041] The specific embodiments of the utility model are described above with reference to the drawings, but those skilled in the art should understand that the above examples are only for illustration, and are not intended to limit the scope of the utility model. Those skilled in the art should understand that the above examples can be modified without departing from the scope and spirit of the utility model. The protection scope of the utility model is defined by the appended claims.

Claims

1. A retroreflective measurement device, characterized in that The application relates to a light shielding unit (1) provided with a directional light source (2) and an array detector (3), a measured sample (4) is arranged on a sample table in the light shielding unit (1) or is arranged outside the light shielding unit (1), a light beam emitted by the directional light source (2) is directed to irradiate the measured sample (4), and the array detector (3) is arranged on a return reflection light path and receives return reflection light beams of the measured sample (4).

2. The retro-reflective measurement device of claim 1, wherein, A hole mirror (5) is arranged in front of the directional light source (2), the hole mirror (5) is located in a light path from the directional light source (2) to the measured sample (4) and also in a light path from the measured sample (4) to the array detector (3), a light beam emitted by the directional light source (2) passes through the hole mirror (5), and return reflection light beams emitted by the measured sample (4) are reflected by the hole mirror (5) and then enter the array detector (3).

3. The retro-reflective measurement device of claim 2, wherein, A diffusion screen (6) is further arranged on a reflection light path of the hole mirror (5), the array detector (3) is arranged in an imaging measurement unit (7), the imaging measurement unit (7) further comprises an imaging lens, and the imaging measurement unit (7) is arranged to face the diffusion screen (6), wherein the imaging lens images a light spot image on the diffusion screen (6) into the array detector (3).

4. The retroreflective measurement device of claim 2 or 3, wherein, One or more mirrors (8) are further arranged on a light path between the hole mirror (5) and the measured sample (4), the mirror (8) is a plane mirror or a concave mirror or a convex mirror, a light beam emitted by the directional light source (2) passes through a small hole of the hole mirror (5) and the one or more mirrors (8) in sequence, is folded back in a light path and then enters the measured sample (4), and return reflection light beams affected by the measured sample (4) pass through the one or more mirrors (8) and then pass through the hole mirror (5) and finally enter the array detector (3).

5. The retroreflective measurement device of claim 2 or 3, wherein, One or more mirrors (8) are further arranged on a light path between the hole mirror (5) and the array detector (3), the mirror (8) is a plane mirror.

6. The retro-reflective measurement device of claim 1, wherein, The array detector (3) is arranged beside or behind the directional light source (2), and return reflection light emitted by the measured sample (4) directly enters the array detector (3).

7. The retroreflective measurement device of claim 1 or 2 or 3, wherein, The light shielding unit (1) is a light shielding cylinder, the measured sample (4) is arranged outside the light shielding unit (1), an inner surface of the light shielding cylinder is dark, a sampling port (12) is arranged at one end of the light shielding cylinder, the measured sample (4) is irradiated by the directional light source (2) through the sampling port (12) and return reflection light beams.

8. The retro-reflective measurement device of claim 7, wherein, A sample interface (9) is arranged, one side of the sample interface (9) is connected with the sampling port (12), and the measured sample (4) is arranged on the other side of the sample interface (9); the sample interface (9) comprises two or more sample interfaces (9), and each sample interface (9) is arranged at different angles between a normal line of the measured sample (4) and a light beam axis of the directional light source (2); or the sample interface (9) is angle-adjustable.

9. The retroreflective measurement device of claim 2 or 3, wherein, The light shielding unit (1) is a light measurement darkroom, a rotating table (11) is arranged in the light measurement darkroom, and the sample (4) to be measured is arranged on the rotating table (11).

10. The retro-reflective measurement device of claim 1, wherein, The light shielding unit (1) is a light measurement darkroom, a rotating table (11) is arranged in the light measurement darkroom, and the sample (4) to be measured is arranged on the rotating table (11); a diffusion screen (6) is arranged beside the directional light source (2), the diffusion screen (6) faces the sample (4) to be measured on the rotating table (11), the array detector (3) is located in an imaging measurement unit (7), and the imaging measurement unit (7) further comprises an imaging lens, and the imaging measurement unit (7) is arranged to face the diffusion screen (6), wherein the imaging lens images the light spot image on the diffusion screen (6) to the array detector (3).

11. The retroreflective measurement device of claim 1 or 2 or 3, wherein, A standard light source with known light intensity distribution is arranged for calibrating the response of the array detector (3).

12. The retro-reflective measurement device of claim 1 or 2 or 3, wherein, One or more light elimination diaphragms (10) are arranged in the light shielding unit (1).

13. The retroreflective measurement device of claim 1 or 2 or 3, wherein, The directional light source (2) adopts a halogen tungsten lamp, a high-intensity gas discharge lamp, an LED lamp or a laser, or a combination of two or more types of light sources.

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