Belt colorimeter and color measurement method

Abstract

The present application is applicable to the field of color measurement technology, and provides an annular colorimeter and a color measurement method. The annular colorimeter includes a light-shielding shell, a continuous spectrum light source, a first color measurement device, and a diffuse reflection surface. A sampling aperture is provided at the bottom of the light-shielding shell. The continuous spectrum light source is arranged on the inner side of the light-shielding shell, avoiding a position that can directly illuminate the sampling aperture, and projects continuous spectrum light into the interior of the light-shielding shell. The first color measurement device is arranged opposite the detection aperture, receives diffusely reflected light from the sample at the sampling aperture, and measures the intensity of the diffusely reflected light. The diffuse reflection surface directly illuminated by the continuous spectrum light source is attached to the inner wall of the light-shielding shell. The light emitted by the continuous spectrum light source is diffusely reflected by the diffuse reflection surface to illuminate the sampling aperture, thereby improving the controllability of the structure and size of the colorimeter. Since the optical path is folded, the size of the annular colorimeter can be made very small. The light irradiating the sample is more uniform, thereby improving the reproducibility of the instrument.

Description

Technical Field

[0001] The present application relates to the technical field of color measurement, and in particular to a ring-shaped colorimeter and a color measurement method. Background Art

[0002] A zonal colorimeter measures the color of an object by its reflected color. For non-luminous, opaque objects, their color depends on the object's absorption and reflection of various wavelengths. In actual measurement, factors influencing the color measurement result depend not only on the object itself but also on the light source's luminous spectrum, the color sensor's performance parameters, and the relative position of the sample, light source, and color sensor—in other words, the colorimeter's geometric conditions for reflectance measurement.

[0003] The CIE (Commission Internationale de l'Eclairage, International Commission on Illumination) specifies ten geometries for reflectance measurement, one of which is the 45° annular / perpendicular geometry. This geometry's lighting and viewing conditions closely match how the human eye observes printed materials, making it ideal for color measurement in the printing industry.

[0004] 45° annular / vertical annular colorimeter requires illumination from a ring-shaped light source obliquely above the sample. The sample is illuminated by one or more beams of light, with the axis of the illumination beam at 45°±5° to the normal to the sample surface. The angle between the observation direction and the normal to the sample surface does not exceed 10°, and the angle between any light ray of the illumination beam and its axis should not exceed 5°. Using a 45° annular / vertical annular colorimeter can effectively eliminate the influence of specular reflection light from the sample surface on the detection equipment, while minimizing the influence of sample texture and directional selective reflection.

[0005] The 45° annular / vertical colorimetry condition relies on a ring-shaped light source. In traditional solutions, to achieve the 45° annular / vertical condition, the annular colorimeter's lighting element needs to uniformly illuminate the sample at an incident angle of 40° to 50°. Therefore, parameters such as the sample's size, relative position, and posture are often fixed. In other words, these parameters need to be coordinated with the size of the lighting element itself. The size of the entire annular colorimeter is uncontrollable, which is not conducive to the lightweight and miniaturization of the 45° annular / vertical annular colorimeter. Summary of the Invention

[0006] The purpose of this application is to provide a ring-shaped colorimeter, aiming to solve the technical problems of traditional 45° ring-shaped / vertical colorimeter, such as uncontrollable size, large volume and high cost.

[0007] The present application is implemented as follows: a ring-shaped colorimeter includes a light-shielding shell, a continuous spectrum light source, a first color measuring device and a diffuse reflection surface; a sampling aperture for taking color from a sample is opened at the bottom of the light-shielding shell; the continuous spectrum light source is arranged on the inner side of the light-shielding shell, and the continuous spectrum light source is arranged to avoid a position where it can directly illuminate the sampling aperture, and is used to project continuous spectrum light into the interior of the light-shielding shell; the first color measuring device is arranged directly opposite to the sample, and is used to receive the diffusely reflected light of the sample at the sampling aperture and measure the color of the diffusely reflected light; the diffuse reflection surface is attached to the inner wall of the light-shielding shell, and the diffuse reflection surface is directly illuminated by the continuous spectrum light source, and is used to diffusely reflect the continuous spectrum light to the sampling aperture.

[0008] In one embodiment of the present application, the annular colorimeter also includes an aperture sleeve, which is arranged on the inner side of the light-shielding shell and connected to the top of the light-shielding shell. The bottom of the aperture sleeve is aligned with the sampling aperture. The first color measuring device is arranged on the inner side of the aperture sleeve. The aperture sleeve forms a detection aperture for allowing the diffusely reflected light of the sample to pass through and illuminate the first color measuring device, and the continuous spectrum light source is arranged to avoid being able to directly illuminate the detection aperture and the sampling aperture.

[0009] In one embodiment of the present application, the continuous spectrum light source is arranged around the aperture sleeve, and the continuous spectrum light source is arranged on the top of the light-shielding shell, and the diffuse reflection surface is arranged around the inner side wall of the light-shielding shell.

[0010] In one embodiment of the present application, the diffuse reflection surface is also attached to the top surface of the inner side of the light-shielding shell, and the aperture sleeve and the diffuse reflection surface limit the incident angle of the diffuse reflection light irradiating the sampling aperture to 40° to 50°.

[0011] In one embodiment of the present application, the surface of the aperture sleeve is black, and the portion of the inner side of the light-shielding shell where the diffuse reflection surface is not provided is black.

[0012] In one embodiment of the present application, the diffuse reflection surface is composed of a diffuse reflection film attached to the inner side of the light-shielding shell, and the inner side surface of the light-shielding shell is provided with a groove for accommodating the diffuse reflection film.

[0013] In one embodiment of the present application, the annular colorimeter also includes a second color measuring device for measuring the intensity of the reflected light of the diffuse reflection surface. The second color measuring device is arranged on the inner side of the light-shielding shell, and the second color measuring device is arranged to avoid a position where the sampling aperture and the continuous spectrum light source can be directly observed.

[0014] In one embodiment of the present application, the continuous spectrum light source and the second color measurement device are arranged side by side on the top inner side of the light shielding shell.

[0015] Another object of the present application is a color measurement method applicable to the above-mentioned endless belt colorimeter, for measuring the reflectance value of a sample, comprising:

[0016] Obtaining calibration parameters: the endless belt colorimeter measures a standard sample and records the intensity of the reflected light of the standard sample obtained by the first color measurement device when measuring the standard sample, and the intensity of the reflected light of the diffuse reflection surface obtained by the second color measurement device when measuring the standard sample;

[0017] Acquiring light intensity: the endless belt colorimeter receives the intensity of the reflected light of the diffuse reflection surface acquired by the second color measuring device, and the intensity of the reflected light of the sample acquired by the first color measuring device;

[0018] Solving the sample reflectance: the annular colorimeter solves the light source attenuation rate of the continuous spectrum light source based on the reflected light intensity of the diffuse reflection surface and the reflected light intensity of the sample, and corrects the reflected light intensity of the sample based on the light source attenuation rate.

[0019] In one embodiment of the present application, in the step of obtaining calibration parameters, the standard sample includes a standard whiteboard and a standard blackboard, and obtaining the calibration parameters specifically includes:

[0020] The endless belt colorimeter measures the standard white plate, and receives the intensity of the reflected light of the standard white plate obtained by the first color measuring device, and the intensity of the reflected light of the diffuse reflection surface obtained by the second color measuring device when measuring the standard white plate;

[0021] The endless belt colorimeter measures the standard blackboard, receives the reflected light intensity of the standard blackboard obtained by the first color measuring device, and the reflected light intensity of the diffuse reflection surface obtained by the second color measuring device when measuring the standard blackboard.

[0022] The implementation of the annular belt colorimeter of the present application has at least the following beneficial effects:

[0023] Part of the inner wall of the light-shielding shell is set as a diffuse reflection surface. The light emitted by the continuous spectrum light source is irradiated on the diffuse reflection surface, and the entire internal space of the light-shielding shell is illuminated by diffuse reflection, and then the surface of the sample is illuminated and the surface color of the sample is detected by the first color measuring device, so that the specific parameters of the surface color of the sample can be obtained; the continuous spectrum light source avoids being set at a position where it can directly illuminate the sampling aperture, and instead realizes uniform light illumination of the sample by irradiating the diffuse reflection surface. Then, by setting the specific shape and position of the diffuse reflection surface, the incident angle of the light emitted by the continuous spectrum light source when irradiating the sample can be controlled. In this way, the annular colorimeter achieves annular uniform illumination of the sample at an incident angle of 40° to 50° through the diffuse reflection surface. There is no need to specially arrange the size of the continuous spectrum light source, as well as the relative position and relative posture of the continuous spectrum light source and the sample, to achieve the 45° annular / vertical colorimetry conditions specified by CIE, thereby improving the controllability of the structure and size of the annular colorimeter; moreover, the light emitted by the continuous spectrum light source is diffusely reflected by the diffuse reflection surface before being irradiated to the sampling aperture, and the sample is annularly uniformly illuminated at an incident angle of 40° to 50°. Since the optical path is folded, the size of the annular colorimeter can be made very small, thereby improving the portability of the annular colorimeter; in addition, the light emitted by the continuous spectrum light source is diffusely reflected by the diffuse reflection surface before being irradiated to the sampling aperture. The diffuse reflection surface has a light averaging effect, which makes the light spot irradiated to the sample more uniform, thereby improving the accuracy of the instrument's measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 1 is a schematic structural diagram of an annular belt colorimeter provided in one embodiment of the present application;

[0026] Figure 2 yes Figure 1 Schematic cross-sectional view of the portion of the annular colorimeter used for color measurement shown in FIG;

[0027] Figure 3 yes Figure 1 An exploded schematic diagram of the portion of the belt colorimeter used for color measurement shown in FIG.

[0028] Figure 4 yes Figure 1 Schematic diagram of the structural layout of the top of the light-shielding shell of the annular colorimeter shown in FIG;

[0029] Figure 5 yes Figure 2 Schematic diagram of the color measurement principle of the ring-shaped colorimeter shown in;

[0030] Figure 6 1 is a flow chart of a color measurement method provided by an embodiment of the present application.

[0031] The reference numerals used in the above drawings are as follows:

[0032] 11-light shielding shell; 110-diffuse reflection surface; 1101-snap-lock structure; 111-sampling aperture; 112-detection aperture; 113-groove; 12-continuous spectrum light source; 131-first color measurement device; 132-second color measurement device; 14-aperture sleeve; 2-sample; 3-wireless connection module; 4-power module; 5-control module. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0034] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be located directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and cannot be understood as limitations on this technical solution. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0035] In order to illustrate the technical solution described in this application, the following is a detailed description with reference to specific drawings and embodiments.

[0036] See also Figures 2 to 4The present application is implemented as follows: an annular colorimeter includes a light-shielding shell 11, a continuous spectrum light source 12, a first color measuring device 131 and a diffuse reflection surface 110; a sampling aperture 111 for sampling color from a sample 2 is opened at the bottom of the light-shielding shell 11; the continuous spectrum light source 12 is arranged on the inner side of the light-shielding shell 11, and the continuous spectrum light source 12 is arranged to avoid a position where it can directly illuminate the sampling aperture 111, and is used to project continuous spectrum light into the interior of the light-shielding shell 11; the first color measuring device 131 is arranged directly opposite the sample 2, and is used to receive the diffusely reflected light of the sample 2 at the sampling aperture 111 and measure the light intensity of the diffusely reflected light; the diffuse reflection surface 110 is attached to the inner wall of the light-shielding shell 11, and the diffuse reflection surface 110 is directly illuminated by the continuous spectrum light source 12, and is used to diffusely reflect the continuous spectrum light to the sampling aperture 111.

[0037] Specifically, the annular colorimeter provided in this embodiment works as follows:

[0038] See also Figure 5 The sampling aperture 111 is aligned with the sample 2, and the continuous spectrum light source 12 transmits continuous spectrum light into the interior of the light-shielding shell 11. The continuous spectrum light is diffusely reflected by the diffuse reflection surface 110 attached to the inner wall of the light-shielding shell 11, illuminating the entire interior space of the light-shielding shell 11, thereby illuminating the surface of the sample 2. While the light illuminates the surface of the sample 2 in an annular band at an incident angle of 45°, it is diffusely reflected again on the surface of the sample 2. Part of the diffusely reflected light is received by the first color measurement device 131. The first color measurement device 131 can obtain specific parameters of the surface color of the sample 2 through analysis based on the received diffusely reflected light.

[0039] The implementation of the annular belt colorimeter provided in this embodiment can achieve at least the following beneficial effects:

[0040] Part of the inner wall of the light-shielding shell 11 is set as a diffuse reflection surface 110. The light emitted by the continuous spectrum light source 12 is irradiated on the diffuse reflection surface 110, and the entire internal space of the light-shielding shell 11 is illuminated through diffuse reflection, thereby illuminating the surface of the sample 2 and the surface color of the sample 2 is detected by the first color measuring device 131, so that the specific parameters of the surface color of the sample 2 can be obtained; the continuous spectrum light source 12 avoids being set in a position where it can directly illuminate the sampling aperture 111, and instead realizes uniform light illumination of the sample 2 by irradiating the diffuse reflection surface 110. Then, by setting the specific shape and position of the diffuse reflection surface 110, the incident angle of the light emitted by the continuous spectrum light source 12 when irradiating the sample 2 can be controlled. In this way, the annular colorimeter achieves uniform annular illumination of sample 2 at an angle of incidence of 40° to 50° through the diffuse reflection surface. This eliminates the need to specifically adjust the size of the continuous spectrum light source 12, or the relative position and orientation of the continuous spectrum light source 12 and sample 2, in order to achieve the 45° annular / vertical colorimetry conditions specified by the CIE. This improves the controllability of the structure and size of the annular colorimeter. Furthermore, the light emitted by the continuous spectrum light source 12 is diffusely reflected by the diffuse reflection surface 110 before irradiating the sampling aperture 111. This provides uniform annular illumination of the sample at an angle of incidence of 40° to 50°. Because the optical path is folded, the annular colorimeter can be made very small, improving its portability. The light emitted by the continuous spectrum light source 12 is diffusely reflected by the diffuse reflection surface 110 before irradiating the sampling aperture 111. The diffuse reflection surface 110 provides uniform light, making the light spot irradiated on sample 20 more uniform and improving the accuracy of the instrument's measurement results.

[0041] See also Figures 2 to 4 In one embodiment of the present application, the annular colorimeter further includes an aperture sleeve 14, which is disposed on the inner side of the light-shielding shell 11 and connected to the top of the light-shielding shell 11. The bottom of the aperture sleeve 14 is aligned with the sampling aperture 111, and the first color measuring device 131 is disposed on the inner side of the aperture sleeve 14. The aperture sleeve 14 forms a detection aperture 112 for allowing diffusely reflected light of the sample 2 to pass through and illuminate the first color measuring device 131.

[0042] The purpose of providing the aperture sleeve 14 is to block the light from the continuous spectrum light source 12 that directly illuminates the sampling aperture 111, preventing the continuous spectrum light from being directly projected onto the sample 2, thereby reducing or even avoiding the mirror reflection effect on the surface of the sample 2 and the fluorescence effect on the surface of the sample 2 under ultraviolet irradiation, and also avoiding uneven illumination brightness on the surface of the sample 2, ultimately improving the accuracy of the measurement results. The aperture sleeve 14 can also be used to limit the range of the incident angle of light when the diffuse reflection surface 110 illuminates the sampling aperture 111, facilitating the control of the incident angle of the continuous spectrum light. Another function of the aperture sleeve 14 is to control the field of view of the first color measurement device 131, preventing the first color measurement device 131 from detecting light outside the sampling aperture 111, thereby ensuring the accuracy of the measurement results of the first color measurement device 131.

[0043] See also Figures 2 to 4 In one embodiment of the present application, a continuous spectrum light source 12 is disposed around an aperture sleeve 14 and is positioned at the top of a light-shielding housing 11. A diffuse reflective surface 110 is disposed around the inner sidewall of the light-shielding housing 11. The aperture sleeve 14 and diffuse reflective surface 110 work together to control the angle of incident light, facilitating the design of an optical path to illuminate the sampling aperture 111 at an angle of 40° to 50°. Both the continuous spectrum light source 12 and the diffuse reflective surface 110 are disposed around the sampling aperture 111, thereby improving the uniformity of the illumination of the sampling aperture 111.

[0044] See also Figure 2 and Figure 3 In one embodiment of the present application, the diffuse reflection surface 110 is also attached to the top surface of the inner side of the light shielding shell 11, and the aperture sleeve 14 and the diffuse reflection surface 110 limit the incident angle of the diffuse reflection light irradiating the sampling aperture 111 to 40°~50°.

[0045] As a specific solution of this embodiment, the diffuse reflection surface 110 is arranged at a position on the top of the light-shielding shell 11 where no other components are arranged. The light emitted by the continuous spectrum light source 12 can be irradiated to the sampling aperture 111 after multiple diffuse reflections, and this part of the diffuse reflection surface 110 is also blocked by the aperture sleeve 14 and will not directly irradiate the sampling aperture 111. In this way, the light intensity and uniformity of the light illuminating the sampling aperture 111 can be improved without destroying the 45° annular / vertical measurement conditions.

[0046] In one embodiment of the present application, the surface of the aperture sleeve 14 is black, and the portion of the inner side of the light-shielding shell 11 not provided with the diffuse reflection surface 110 is black. In this way, the incident angle of the continuous spectrum light when irradiating the sampling aperture 111 can be controlled within the range of 40° to 50°, meeting the 45° annular / vertical measurement conditions, and can eliminate light from outside the sample 2, preventing the color of the inner side of the light-shielding shell 11 itself from interfering with the measurement results of the first color measurement device 131.

[0047] See also Figure 2 and Figure 3 In one embodiment of the present application, the diffuse reflection surface 110 is composed of a diffuse reflection film attached to the inner side of the light-shielding shell 11. This can simplify the extinction treatment of the inner wall of the light-shielding shell 11, simplify the production and manufacturing of the diffuse reflection surface 110 and the annular colorimeter; the inner side surface of the light-shielding shell 11 is provided with a groove 113 for accommodating the diffuse reflection film, further simplifying the assembly of the annular colorimeter.

[0048] In this embodiment, a diffuse reflection film is attached to the inner side of the light-shielding shell 11, which can simplify the manufacturing process of the diffuse reflection surface 110 and the annular colorimeter. It is only necessary to perform a matte treatment on the entire light-shielding shell 11 and then install the diffuse reflection film on the groove 113 of the inner wall of the light-shielding shell 11. No diffuse reflection material is left at the position on the inner wall of the light-shielding shell 11 that requires matte treatment. This can prevent light from being directly irradiated to the first color measurement device 131 after being reflected from other positions on the inner wall of the light-shielding shell 11. The incident angle of the diffusely reflected light from the continuous spectrum light source 12 when irradiating the sample 2 is strictly controlled, reducing costs while making the boundary of the diffuse reflection surface 110 sharper, and also improving the uniformity of the angular distribution of the light intensity irradiated on the surface of the sample 2 to be measured, ultimately improving the accuracy of the measurement results of the annular colorimeter.

[0049] As a specific solution of this embodiment, the diffuse reflection film is prepared by a die-cutting process and is provided with a snap-fit ​​structure 1101, which can snap into a ring shape at both ends, further simplifying the manufacturing process and the assembly of the ring-shaped colorimeter.

[0050] As a preferred solution of this embodiment, the diffuse reflection diaphragm adopts an anti-UV (Ultra Violet) diaphragm, that is, the diffuse reflection diaphragm is provided with an anti-ultraviolet layer, which can prevent the ultraviolet band light in the continuous spectrum light source 12 from irradiating the sample 2, causing the sample 2 to emit fluorescence under the excitation of ultraviolet light, affecting the accuracy of the detection results.

[0051] See also Figure 2 As a preferred solution of this embodiment, after the diffuse reflection diaphragm is installed, the conical surface on which it is located forms an angle of 5° with the central normal of the sampling aperture 111. This can increase the light intensity of the continuous spectrum light source 12 when it is reflected by the diffuse reflection diaphragm onto the sampling aperture 111, and improve the signal strength received by the first color measurement device 131, so that the first color measurement device 131 can obtain the best responsiveness, which is beneficial for the annular colorimeter to process the reflected light signal of the sample 2 and improve the stability of the annular colorimeter's measurement results.

[0052] See also Figures 2 to 4In one embodiment of the present application, the annular colorimeter further includes a second color measuring device 132 for measuring the intensity of reflected light from the diffuse reflection surface 110 . The second color measuring device 132 is arranged to avoid a position where the sampling aperture 111 and the continuous spectrum light source 12 can be directly observed, and the second color measuring device 132 is arranged on the inner side of the light shielding shell 11 .

[0053] The second color measurement device 132 is used to receive and measure the diffusely reflected light from the diffuse reflection surface 110, thereby obtaining the intensity of the light inside the light-shielding shell 11 across the entire frequency band and monitoring its changes in real time. The second color measurement device 132 is used to correct the measurement results of the first color measurement device 131, thereby eliminating the influence of changes in the intensity of the light emitted by the continuous spectrum light source 12 itself on the measurement results of the first color measurement device 131, as well as the influence of the color of the sample 2 itself on the measurement results of the first color measurement device 131. This eliminates the need for repeated debugging and calibration of the colorimeter during use, thereby improving the reproducibility of the colorimeter's measurement results.

[0054] See also Figures 2 to 4 In one embodiment of the present application, the continuous spectrum light source 12 and the second color measurement device 132 are arranged side by side at the top inner side of the light-shielding shell 11. In this way, the aperture sleeve 14 blocks the light directly irradiated from the sampling aperture 111 to the second color measurement device 132, thereby improving the accuracy of the results of the second color measurement device 132 measuring the color of the diffuse reflection surface 110.

[0055] As a specific solution of this embodiment, the first color measuring device 131 and / or the second color measuring device 132 uses a photodetector to respectively measure the light intensity values ​​of three colors in the reflected light intensity of the sample 2 and obtain the color of the sample 2 through calculation.

[0056] See also Figures 2 to 4 As a specific solution of this embodiment, the second color measurement device 132 and the continuous spectrum light source 12 are disposed on the same PCB board. This design facilitates optimization of the circuit layout of the annular colorimeter and eliminates the need for a separate optical path for the second color measurement device, simplifying the structure of the annular colorimeter and reducing its cost. Furthermore, because the fields of view of both the second color measurement device 132 and the light source need to avoid the detection aperture 112 and the sampling aperture, the spectral changes of the continuous spectrum light source 12 can be conveniently monitored by the second color measurement device 132, and direct illumination of the continuous spectrum light source 12 by the second color measurement device 132 can be prevented. Preferably, the continuous spectrum light source 12 is composed of a plurality of light source elements surrounding an aperture sleeve, and the second color measurement device 132 is disposed between two adjacent light source elements. This further improves the accuracy of the measurement results of the second color measurement device 132, thereby ensuring that the measurement results of the second color measurement device 132 correct the measurement results of the first color measurement device 131.

[0057] See also Figure 1 In one embodiment of the present application, the annular colorimeter further includes a standard sample, a wireless connection module 3, a power module 4, and a control module 5. The power module 4 is used to power the entire annular colorimeter, and preferably includes a lithium battery and a charging port; the control module 5 directly drives the continuous spectrum light source 12 to emit light, and the first color measuring device 131 and the second color measuring device 132 are connected to the control module 5. During measurement, the control module 5 first lights up the continuous spectrum light source 12, and then simultaneously collects the light intensity value of the first color measuring device 131 and the light intensity value of the second color measuring device 132. After the collection is completed, the continuous spectrum light source 12 is turned off to achieve the purpose of saving power; the control module 5 calculates the reflectance value of the sample 2 based on the measured data and the calibration data stored in the control module 5, and finally converts it into a chromaticity value for display; the standard sample is fixed on the base of the instrument, which is convenient for calibrating the annular colorimeter at any time, avoiding errors caused by aging of optical components, rapid changes in ambient temperature, etc., and further improving accuracy. When calibration is required, simply attach the base to the main housing, and the standard sample will fit snugly against the measurement port. The colorimeter then measures the standard sample and stores the results in the control module 5. The wireless connection module 3 is preferably a Bluetooth connection module, which connects the colorimeter to a mobile phone. The mobile phone app allows for color readings in various formats, including Lab, Luv, LCH, Yxy, CMYK, and RGB. It also allows for convenient color difference calculations, such as ΔE*ab, ΔE*uv, ΔE*94, ΔE*cmc, and ΔE*00, on the phone.

[0058] Another object of the present application is a color measurement method applicable to the above-mentioned endless belt colorimeter, for measuring the reflectance value of sample 2, comprising:

[0059] Obtaining calibration parameters: The endless belt colorimeter measures the standard sample and records the intensity of the reflected light of the standard sample obtained by the first color measurement device 131 when measuring the standard sample, and the intensity of the reflected light of the diffuse reflection surface 110 obtained by the second color measurement device 132 when measuring the standard sample;

[0060] Obtaining light intensity: The annular colorimeter receives the intensity of the reflected light of the diffuse reflection surface 110 obtained by the second color measurement device 132 and the intensity of the reflected light of the sample 2 obtained by the first color measurement device 131;

[0061] Calculating the reflectivity of sample 2: The annular colorimeter calculates the light source attenuation rate of the continuous spectrum light source 12 based on the reflected light intensity of the diffuse reflection surface 110 and the reflected light intensity of sample 2, and corrects the reflected light intensity of sample 2 based on the light source attenuation rate.

[0062] The color measurement method provided in this embodiment can achieve at least the following beneficial technical effects:

[0063] Because the optical environment inside the light-shielding housing 11 behind the sample 2 is complex, and the spectrum of the light emitted by the continuous-spectrum light source 12 changes over time as conditions such as temperature change, there is a certain error between the measured reflectivity value of the sample 2 by the first color measurement device 131 and the actual reflectivity value of the sample 2. Therefore, a second color measurement device 132 is introduced to correct the measurement results of the first color measurement device 131 by monitoring the intensity changes of the continuous-spectrum light inside the light-shielding housing 11 in various frequency bands in real time. Calibration parameters are obtained by measuring standard samples and used to compensate for the measurement values ​​obtained by the first color measurement device 131. This method can greatly reduce the error in the measurement results of the sample 2 by the annular colorimeter through two approximation calculations.

[0064] As a preferred solution of this embodiment, the control module 5 is provided with a memory structure for storing the calibration parameters obtained in the step of obtaining the calibration parameters.

[0065] In one embodiment of the present application, in the step of obtaining calibration parameters, the standard sample includes a standard whiteboard and a standard blackboard, and obtaining the calibration parameters specifically includes:

[0066] The endless belt colorimeter measures the standard white plate, receives the intensity of the reflected light of the standard white plate obtained by the first color measuring device 131, and the intensity of the reflected light of the diffuse reflection surface 110 obtained by the second color measuring device 132 when measuring the standard white plate;

[0067] The endless belt colorimeter measures the standard blackboard and receives the reflected light intensity of the standard blackboard obtained by the first color measuring device 131 and the reflected light intensity of the diffuse reflection surface 110 obtained by the second color measuring device 132 when measuring the standard blackboard.

[0068] As a preferred solution of this embodiment, the control module 5 is provided with a memory structure for storing the reflected light intensity of the standard whiteboard obtained by the first color measurement device 131, the reflected light intensity of the diffuse reflection surface 110 obtained by the second color measurement device 132 when measuring the standard whiteboard, the reflected light intensity of the standard blackboard obtained by the first color measurement device 131, and the reflected light intensity of the diffuse reflection surface 110 obtained by the second color measurement device 132 when measuring the standard blackboard.

[0069] As a specific solution of this embodiment, the annular colorimeter corrects for the light source attenuation rate. When continuous spectrum light passes through diffuse reflection surface 110 and illuminates sampling aperture 111, some of the light is diffusely reflected by sample 2 and then reflects back to diffuse reflection surface 110. After diffuse reflection by diffuse reflection surface 110, it illuminates second color measurement device 132. As a result, the light intensity detected by second color measurement device 132 changes with the reflectivity of measured sample 2. Correcting the light source attenuation rate helps further improve the accuracy and reproducibility of the color measurement results of sample 2 by first color measurement device 131.

[0070] The following is a specific example to illustrate the color measurement method provided by this embodiment and its technical effects:

[0071] See also Figure 6 In this embodiment, the color measurement method includes:

[0072] S1: Obtain calibration parameters: The belt colorimeter measures the standard white plate and receives the reflected light intensity I of the standard white plate obtained by the first color measurement device 131. 11 , and the reflected light intensity I of the diffuse reflection surface 110 obtained by the second color measurement device 132 when measuring the standard white plate 21 , the reflectivity of the standard white plate is R1;

[0073] The ring belt colorimeter measures the standard blackboard and receives the reflected light intensity I of the standard blackboard obtained by the first color measurement device 131. 12 , and the reflected light intensity I of the diffuse reflection surface 110 obtained by the second color measurement device 132 when measuring the standard blackboard 22 , the reflectivity of the standard blackboard is R2;

[0074] S2: Obtaining light intensity: The endless belt colorimeter measures sample 2, receives the reflected light intensity I1 of sample 2 obtained by the first color measurement device 131, and obtains a preliminary color measurement result R0 of sample 2 (i.e., the uncorrected color detection result of sample 2), as well as the reflected light intensity I2 of the diffuse reflection surface 110 obtained by the second color measurement device 132 when measuring sample 2;

[0075] S3: Calculating the reflectivity of sample 2: The annular colorimeter calculates the light source attenuation rate of the continuous spectrum light source 12 based on the reflected light intensity of the diffuse reflection surface 110 and the reflected light intensity of sample 2, and corrects the reflected light intensity of sample 2 based on the light source attenuation rate.

[0076] Specifically, solving the reflectivity of sample 2 includes:

[0077] The annular colorimeter corrects the light source attenuation rate A, specifically:

[0078]

[0079] Where h is the influence coefficient, R0 is the uncorrected color test result of sample 2, specifically:

[0080]

[0081]

[0082] The final reflectivity value of sample 2 is:

[0083]

[0084] The complex optical environment within the light-shielding housing 11 affects the colorimetric results of the first color measurement device. For example, as conditions such as temperature change, the spectrum of light emitted by the continuous-spectrum light source 12 also varies over time, causing a certain error between the reflectivity value of sample 2 measured by the first color measurement device 131 and the actual reflectivity of sample 2. Furthermore, when the continuous-spectrum light passes through the diffuse reflection surface 110 and strikes the sampling aperture 111, some of the light is diffusely reflected by sample 2 and then strikes the diffuse reflection surface 110, where it is then diffusely reflected by the diffuse reflection surface 110 and strikes the first color measurement device 131, resulting in a certain error in the measurement results of the first color measurement device 131. Therefore, the second color measurement device 132 is introduced to correct for the error in the continuous-spectrum light emitted by the continuous-spectrum light source 12, while also correcting for the error in the first color measurement device 131 caused by the diffuse reflection of sample 2. Combining these two factors, the measurement results of the first color measurement device 131 are corrected and compensated. This double-approximation calculation significantly reduces the error in the measurement results of sample 2 by the annular colorimeter.

[0085] It should be understood that this embodiment provides the most complete color measurement method. In actual use, multiple measurements can be performed after the step of obtaining the calibration parameters is implemented on the ring-shaped colorimeter. That is, in actual use, the step of obtaining the calibration parameters can be followed by multiple steps of obtaining the light intensity and solving the reflectance of sample 2, without the need to perform a calibration each time before measuring the color of sample 2.

[0086] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A ring-shaped colorimeter, characterized in that: include: A light-shielding shell, wherein a sampling aperture for sampling color from a sample is provided at the bottom of the light-shielding shell; a continuous spectrum light source, the continuous spectrum light source being disposed inside the light-shielding shell and being arranged so as to avoid direct illumination of the sampling aperture, and being configured to project continuous spectrum light into the interior of the light-shielding shell; a first color measurement device, disposed facing the sample and configured to receive diffusely reflected light from the sample at the sampling aperture and measure the intensity of the diffusely reflected light; as well as a diffuse reflection surface, the diffuse reflection surface being attached to the inner wall of the light-shielding shell, the diffuse reflection surface being directly illuminated by the continuous spectrum light source and being used to diffusely reflect the continuous spectrum light to the sampling aperture; The annular colorimeter further includes a second color measurement device for measuring the intensity of the reflected light from the diffuse reflection surface, the continuous spectrum light source and the second color measurement device are arranged side by side on the top inner side of the light shielding shell, and the second color measurement device and the continuous spectrum light source are arranged on the same PCB board; When measuring the reflectance value of a sample, the annular belt colorimeter is used to: Receive the reflected light intensity I of the standard white plate obtained by the first color measurement device 11 , and the reflected light intensity I of the diffuse reflection surface obtained by the second color measurement device when measuring the standard white plate 21 The reflectivity of the standard white board is R1; the ring belt colorimeter measures the standard blackboard and receives the reflected light intensity I of the standard blackboard obtained by the first color measurement device. 12 , and the reflected light intensity I of the diffuse reflection surface obtained by the second color measurement device when measuring the standard blackboard 22 , the reflectivity of the standard blackboard is R2; receiving the reflected light intensity I2 of the diffuse reflection surface obtained by the second color measurement device when measuring the sample, and the reflected light intensity I1 of the sample obtained by the first color measurement device, to obtain a preliminary color measurement result R0 of the sample; Correct the light source attenuation rate A so that The reflected light intensity of the sample is corrected according to the attenuation rate of the light source, so that the reflectivity value of the sample is finally obtained. Where h is the influence coefficient, This is to correct the error of the change of the continuous spectrum light emitted by the continuous spectrum light source, and to correct the error of the first color measurement device itself caused by the diffuse reflection light of the sample.

2. The endless belt colorimeter according to claim 1, wherein: The annular colorimeter also includes an aperture sleeve, which is arranged on the inner side of the light-shielding shell and connected to the top of the light-shielding shell. The bottom of the aperture sleeve is aligned with the sampling aperture. The first color measuring device is arranged on the inner side of the aperture sleeve. The aperture sleeve forms a detection aperture for allowing the diffusely reflected light of the sample to pass through and illuminate the first color measuring device, and the continuous spectrum light source is arranged to avoid being able to directly illuminate the detection aperture and the sampling aperture.

3. The endless belt colorimeter according to claim 2, wherein: The continuous spectrum light source is arranged around the aperture sleeve, and the continuous spectrum light source is arranged on the top of the light-shielding shell, and the diffuse reflection surface is arranged around the inner side wall of the light-shielding shell.

4. The endless belt colorimeter according to claim 3, wherein: The diffuse reflection surface is also attached to the top surface of the inner side of the light shielding shell. The aperture sleeve and the diffuse reflection surface limit the incident angle of the diffuse reflection light irradiating the sampling aperture to be 40° to 50°.

5. The endless belt colorimeter according to claim 2, wherein: The surface of the aperture sleeve is black, and the portion of the inner side of the light-shielding shell where the diffuse reflection surface is not provided is black.

6. The endless belt colorimeter according to claim 2, wherein: The diffuse reflection surface is composed of a diffuse reflection film attached to the inner side of the light-shielding shell, and the inner side surface of the light-shielding shell is provided with a groove for accommodating the diffuse reflection film.

7. A color measurement method, characterized in that: The color measurement method is applicable to the endless belt colorimeter according to any one of claims 1 to 6, wherein the endless belt colorimeter is used to measure the reflectance value of a sample; the color measurement method comprises: Obtaining calibration parameters: The endless belt colorimeter measures the standard sample and records the reflected light intensity of the standard sample obtained by the first color measuring device when measuring the standard sample, and the reflected light intensity of the diffuse reflection surface obtained by the second color measuring device when measuring the standard sample; it includes: receiving the reflected light intensity I of the standard white plate obtained by the first color measuring device 11 , and the reflected light intensity I of the diffuse reflection surface obtained by the second color measurement device when measuring the standard white plate 21 The reflectivity of the standard white board is R1; the ring belt colorimeter measures the standard blackboard and receives the reflected light intensity I of the standard blackboard obtained by the first color measurement device. 12 , and the reflected light intensity I of the diffuse reflection surface obtained by the second color measurement device when measuring the standard blackboard 22 , the reflectivity of the standard blackboard is R2; Obtaining light intensity: The endless belt colorimeter receives the reflected light intensity I2 of the diffuse reflection surface obtained by the second color measuring device when measuring the sample, and the reflected light intensity I1 of the sample obtained by the first color measuring device, to obtain a preliminary color measurement result R0 of the sample; Solving the sample reflectance: The annular colorimeter solves the light source attenuation rate of the continuous spectrum light source based on the reflected light intensity I2 of the diffuse reflection surface and the reflected light intensity I1 of the sample obtained when measuring the sample, and corrects the light source attenuation rate A so that The reflected light intensity of the sample is corrected according to the attenuation rate of the light source, so that the reflectivity value of the sample is finally obtained. Where h is the influence coefficient, This is to correct the error of the change of the continuous spectrum light emitted by the continuous spectrum light source, and to correct the error of the first color measurement device itself caused by the diffuse reflection light of the sample.

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