A standard light source detection system and its detection method

Abstract

The present invention discloses a standard light source detection system and a detection method thereof, which includes a detection chamber, a detection table installed in the detection chamber, and a light source module installed at the top of the detection chamber directly facing the detection table. The irradiation surface of the light source module completely covers the area to be detected on the detection table. An acquisition module, a data processing module, and a control module are sequentially and signal-connected in the detection chamber. The control module is signal-connected to the light source module. The acquisition module includes a light source detection sensor installed in the area to be detected and a reflected light detection sensor installed in the detection chamber and matching with the light source detection sensor. By setting the light source detection sensor and the reflected light detection sensor to detect the color temperature and color rendering property of the light source, and combining the color temperature and color rendering property to jointly judge the performance quality of the light source, the reliability of the light source during the comparison of printed products is improved, the color error caused by the light source quality is reduced, and the situation of misjudging the quality of the printed product is avoided, thereby improving the yield of the printed product.

Description

Technical Field

[0001] The present invention relates to a standard light source detection system and a detection method thereof, belonging to the technical field of light source detection for printed matter. Background Art

[0002] In the process of quality control and color management applications in the printing industry, accurately evaluating the color difference of products is a very important part, and the standard light source plays an important role. The color of the printing ink on the surface of the substrate is not only restricted by its own chromaticity, but also related to various factors such as the light source, viewing angle, and the observer's own conditions during visual color measurement. Different light sources have their own spectral energy distributions and colors. Under their illumination, the colors presented on the surface of the printed matter also change at any time, which may lead to differences in color evaluation.

[0003] During the long-term use of the light source, the performance of the light source will attenuate invisibly, and deviations will occur in the standard requirements of color temperature and brightness. Among them, color temperature and color rendering property are one of the important criteria for evaluating the quality of the light source. The so-called color temperature refers to the temperature that a pure black body needs to reach when it generates the same spectrum as the light source when the light source emits light. The so-called color rendering property refers to the property that different spectral light sources show different colors when illuminating an object of the same color. Usually, the color rendering index Ra is used to represent the color rendering property of the light source, and the color rendering index is a measure of the degree of color matching between the reflected light of a certain color irradiated by a light source and the reflected light of the same color under the illumination of sunlight with the same color temperature. At present, for the evaluation of the quality of the light source for printed matter, relying on a single factor alone cannot accurately judge whether the performance of the light source for the printed matter decays during long-term use, so it is impossible to accurately judge whether the color of the prepared printed matter meets the standard, and it is impossible to accurately distinguish the subtle color deviation of the light source by the human eye alone, ultimately resulting in a significant reduction in the finished product rate. Summary of the Invention

[0004] Object of the Invention: Aiming at the deficiencies in the prior art, the present invention provides a standard light source detection system and a detection method thereof. By setting a light source detection sensor and a reflected light detection sensor to detect the color temperature and color rendering property respectively, and combining the two to jointly evaluate the quality of the light source, the problem of inaccurate evaluation of the light source quality is solved.

[0005] Technical solution: A standard light source detection system, including a detection chamber, a detection table installed in the detection chamber, and a light source module installed at the top of the detection chamber facing the detection table. The irradiation surface of the light source module completely covers the area to be detected on the detection table. An acquisition module, a data processing module, and a control module are sequentially and signal-connected in the detection chamber. The control module is signal-connected to the light source module. The acquisition module includes a light source detection sensor installed in the area to be detected and a reflected light detection sensor installed in the detection chamber and matching the light source detection sensor.

[0006] In the present invention, a supporting light source detection sensor and a reflected light detection sensor are respectively installed on the detection table and in the detection chamber to detect the color temperature and color rendering property of the light source. The light source performance parameters collected by the light source detection sensor and the reflected light detection sensor are sent to the data processing module for processing to obtain the color temperature value and the color rendering index, and to judge whether they are within the qualified range. At the same time, different light sources can be switched through the control module for quality inspection, which not only improves the accuracy of light source quality detection, but also can measure the quality of different light sources. Moreover, it greatly improves the reliability of the light source during the comparison of printed products, reduces the color error caused by the light source quality and thus the misjudgment of the quality of the printed product, and further improves the yield rate of the printed product.

[0007] Preferred option: To improve the accuracy of light source quality inspection, at least four light source detection sensors are evenly installed around the area to be detected. During the illumination of the light source, the light rays irradiating on the edge position of the area to be detected are usually weak and more likely to cause deviation in color evaluation. Therefore, by installing light source detection sensors at the four edges of the area to be detected, the area with the weakest color temperature can be found, and this area can be used as the basis for evaluation. If the light source performance detection of this area is qualified, then the light source performance of other areas must also be qualified, which can not only improve the accuracy of light source quality inspection, but also improve the detection efficiency.

[0008] Preferred option: To make the light source concentrate on irradiating the area to be detected, the light source module includes a light source to be detected and a lampshade sleeved around the light source to be detected. The cross-section of the lampshade is a trapezoid with a smaller upper part and a larger lower part. The lampshade with a trapezoidal cross-section with a smaller upper part and a larger lower part focuses the light rays, enhances the illumination intensity, restricts the irradiation angle of the light rays, makes the illumination more uniform, makes up for the insufficient brightness of the light source, and makes it clearer for personnel to observe the printed product.

[0009] Preferred option: To timely remind personnel of light source quality problems, an alarm module is installed on the detection table, and the alarm module is signal-connected to the control module.

[0010] Preferred option. To enable personnel to monitor the light source quality detection process in real time, it further includes a remote control device signal - connected to the control module. Through the remote control device, corresponding standard light source parameters can be manually set, the light source can be switched, and the corresponding color temperature value and color rendering index can be observed to monitor the detection process in real time, improving convenience.

[0011] A detection method for a standard light source detection system includes the following steps:

[0012] Step 1: The system starts, and standard light source parameters are set, including the standard color temperature range, standard color rendering index range, standard spectral power distribution, and the spectral reflectance of the color card, and are stored in the data - processing module.

[0013] Step 2: The color temperature value Tc of each area in the area to be detected is detected respectively by the light source detection sensor and sent to the data - processing module to obtain the area to be detected with the weakest color temperature.

[0014] Step 3: The data - processing module determines whether the color temperature value of the area to be detected with the weakest color temperature in Step 2 is within the standard color temperature range set for the standard light source. If so, go to Step 4; otherwise, determine that the light source to be tested is unqualified, and the data - processing module sends an alarm signal to the control module, and the control module activates the alarm module.

[0015] Step 4: The data - processing module processes the data of the reflected light of the area with the weakest color temperature in Step 3 measured by the reflected - light detection sensor to obtain the color rendering index Ra of the reflected light, and determines whether it is within the standard color rendering index range. If it is, determine that the light source to be tested is qualified; otherwise, determine that the light source to be tested is unqualified, and the data - processing module sends an alarm signal to the control module, and the control module activates the alarm module.

[0016] The present invention first sets the parameters of the corresponding standard light source and stores them in the data - processing module. Then, it first detects the area to be detected with the weakest color temperature through the light source detection sensor, and determines whether the color temperature value of this area is within the set standard range. If it is not within the range, it is judged as unqualified, and the alarm module is activated to remind the personnel to replace the light source in time. If it is within the range, this area is used as the evaluation basis, and the color rendering index of this area is detected through the reflected - light detection sensor, and it is determined whether the color rendering index is within the set standard range. If it is not within the range, it is judged as unqualified, and the alarm module is activated to remind the personnel to replace the light source in time, improving the accuracy of light source quality detection.

[0017] Preferred option. To save the detection cost, in Step 1, at least 5 groups of different standard light source parameters are set, at least including D65 light source parameters, D50 light source parameters, CWF light source parameters, TL84 light source parameters, and UV light source parameters.

[0018] Preferred option. To detect the color rendering property of the light source, the specific steps of step four are as follows:

[0019] The reflected light detection sensor detects the spectral wavelength λ of the reflected light in this area, sends the spectral wavelength λ to the data processing module, and processes it to obtain the spectral power distribution S 1 (λ), and calculates the weight coefficient P for measuring the difference in spectral power distribution:

[0020]

[0021] where S 1 (λ) is the spectral power distribution of the reflected light, S 2 (λ) is the standard spectral power distribution, R(λ) is the spectral reflectance of the color card, and P is the weight coefficient for measuring the difference in spectral power distribution;

[0022] Calculate the special color rendering index R i :

[0023] R i = 100 - 4.6×ΔE×k×P

[0024] where ΔE is the color difference, k is the proportionality coefficient, P is the weight coefficient for measuring the difference in spectral power distribution, and R i is the special color rendering index;

[0025] Calculate the general color rendering index Ra based on the calculation:

[0026]

[0027] where i represents the i-th standard color card, and R i is the special color rendering index;

[0028] Compare the obtained general color rendering index Ra with the standard color rendering index range to determine whether it is within the standard color rendering index range. If it is, the light source is determined to be qualified; otherwise, the light source is determined to be unqualified. The data processing module sends an alarm signal to the control module, and the control module activates the alarm module.

[0029] Preferred option. To detect the color difference, the calculation method of the color difference ΔE is as follows:

[0030]

[0031] where k i represents the i-th standard color card under the illumination of the light source to be measured, r i represents the i-th standard color card under the illumination of the standard light source, U and V represent the chromaticity coordinates of the color sample, and W represents the lightness.

[0032] Beneficial effects: By setting up a light source detection sensor and a reflected light detection sensor to detect the color temperature and color rendering property of the light source, the present invention combines the color temperature and color rendering property to jointly judge the performance quality of the light source, improves the reliability of the light source during the comparison of printed products, reduces the color error caused by the light source quality and thus the situation of misjudging the quality of the printed product, improves the yield of the printed product, and by installing light source detection sensors around the area to be inspected, improves the detection efficiency and accuracy. At the same time, through the alarm module and the remote control device, it can also timely remind the personnel that there is a quality problem with the light source and monitor the light source detection process in real time, improving the reliability of the entire detection system and the accuracy of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0034] Figure 1 is the structural schematic diagram of the present invention;

[0035] Figure 2 is the structure diagram of the lamp shade of the present invention;

[0036] Figure 3 is the flowchart of the detection method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0039] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the contact between the first and second features through additional features therebetween rather than direct contact. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0040] As Figure 1 shown, a standard light source detection system includes a detection chamber 1, a detection table 2 installed in the detection chamber 1, and a light source module 3 installed at the top of the detection chamber 1 directly facing the detection table 2. The irradiation surface of the light source module 3 completely covers the area to be detected 21 on the detection table 2. A collection module 4, a data processing module 5, and a control module 6 are sequentially and signal-connected in the detection chamber 1. The control module 6 is signal-connected to the light source module 3. The collection module 4 includes a light source detection sensor 41 installed in the area to be detected 21 and a reflected light detection sensor 42 installed in the detection chamber 1 and matching with the light source detection sensor 41.

[0041] By respectively installing a supporting light source detection sensor and a reflected light detection sensor on the detection table and in the detection chamber to detect the color temperature and color rendering property of the light source, and by sending the light source performance parameters collected by the light source detection sensor and the reflected light detection sensor to the data processing module for processing to obtain the color temperature value and color rendering index and judge whether they are within the qualified range, and at the same time, different light sources can be switched through the control module for quality inspection, which not only improves the accuracy of light source quality detection, but also can measure the quality of different light sources, and greatly improves the reliability of the light source during the comparison of printed products, reduces the color error caused by the light source quality and thus the situation of misjudging the quality of the printed product, and further improves the yield of the printed product.

[0042] To improve the accuracy of light source quality inspection, at least four light source detection sensors 41 are evenly installed around the area to be detected 21. During the illumination of the light source, the light rays irradiating on the edge position of the area to be detected are usually weak and are more likely to cause deviation in color evaluation. Therefore, by installing light source detection sensors at the four edges of the area to be detected, the area with the weakest color temperature can be found, and this area is used as the basis for evaluation. If the light source performance detection of this area is qualified, then the light source performance of other areas must also be qualified, which can not only improve the accuracy of light source quality inspection, but also improve the detection efficiency.

[0043] As Figure 2As shown in the figure, in order to make the light source concentrate on the area to be inspected, the light source module 3 includes a light source to be measured 31 and a lamp shade 32 sleeved around the light source to be measured 31. The cross-section of the lamp shade 32 is a trapezoid with a smaller upper part and a larger lower part. By using a lamp shade with a trapezoidal cross-section with a smaller upper part and a larger lower part to focus the light, the illumination intensity is enhanced, the irradiation angle of the light is restricted, the illumination becomes more uniform, compensating for the insufficient brightness of the light source, making it clearer for people to observe printed materials.

[0044] In order to timely remind people of the light source quality problem, an alarm module 7 is installed on the inspection table 2, and the alarm module 7 is signal-connected to the control module 6.

[0045] In order to enable people to monitor the light source quality detection process in real time, it also includes a remote control device signal-connected to the control module 6. Through the remote control device, the corresponding standard light source parameters can be manually set, the light source can be switched, and the corresponding color temperature value and color rendering index can be observed, and the detection process can be monitored in real time, improving the convenience.

[0046] As Figure 3 shown, a detection method of a standard light source detection system includes the following steps:

[0047] Step 1: The system starts, and the standard light source parameters are set, including the standard color temperature range, the standard color rendering index range, the standard spectral power distribution, and the spectral reflectance of the color card, and are stored in the data processing module 5;

[0048] Step 2: The color temperature values Tc of each area of the area to be inspected 21 are respectively detected by the light source detection sensor 41 and sent to the data processing module 5 to obtain the area of the area to be inspected 21 with the weakest color temperature;

[0049] Step 3: The data processing module 5 determines whether the color temperature value of the area of the area to be inspected 21 with the weakest color temperature in Step 2 is within the standard color temperature range according to the set standard color temperature range of the standard light source. If so, go to Step 4; otherwise, determine that the light source to be measured 31 is unqualified, and the data processing module 5 sends an alarm signal to the control module 6, and the control module 6 starts the alarm module 7;

[0050] Step 4: The data processing module 5 processes the data of the reflected light of the area with the weakest color temperature in Step 3 measured by the reflected light detection sensor 42 to obtain the color rendering index Ra of the reflected light, and determines whether it is within the standard color rendering index range. If so, determine that the light source to be measured 31 is qualified, otherwise determine that the light source to be measured 31 is unqualified, and the data processing module 5 sends an alarm signal to the control module 6, and the control module 6 starts the alarm module 7.

[0051] First, set the parameters corresponding to the standard light source and store them in the data processing module. Then, first detect the area to be inspected with the weakest color temperature through the light source detection sensor, and determine whether the color temperature value of this area is within the set standard range. If it is not within the range, it is judged as unqualified, and the alarm module is activated to remind the personnel to replace the light source in time. If it is within the range, then based on this area as the evaluation basis, the reflection light detection sensor is used to detect the color rendering index of this area, and determine whether the color rendering index is within the set standard range. If it is not within the range, it is judged as unqualified, and the alarm module is activated to remind the personnel to replace the light source in time, improving the accuracy of light source quality detection.

[0052] To save the detection cost, in the first step, at least 5 groups of different standard light source parameters are set, which are at least the D65 light source parameters, D50 light source parameters, CWF light source parameters, TL84 light source parameters, and UV light source parameters respectively.

[0053] To detect the color rendering property of the light source, the specific steps of the fourth step are as follows:

[0054] The reflection light detection sensor 42 detects the spectral wavelength λ of the reflected light in this area, and sends the spectral wavelength λ to the data processing module 5 to process and obtain the spectral power distribution S 1 λ, and calculate the weight coefficient P for measuring the difference in spectral power distribution:

[0055]

[0056] Among them, S 1 λ is the spectral power distribution of the reflected light, S 2 λ is the standard spectral power distribution, Rλ is the spectral reflectance of the color card, and P is the weight coefficient for measuring the difference in spectral power distribution;

[0057] Calculate the special color rendering index R i :

[0058] R i = 100 - 4.6×ΔE×k×P

[0059] Among them, ΔE is the color difference, k is the proportionality coefficient, P is the weight coefficient for measuring the difference in spectral power distribution, and R i is the special color rendering index;

[0060] Calculate the general color rendering index Ra according to the calculation:

[0061]

[0062] Among them, i represents the i-th standard color card, and R i is the special color rendering index;

[0063] Compare the obtained general color rendering index Ra with the standard color rendering index range to determine whether it is within the standard color rendering index range. If it is, the light source is determined to be qualified; otherwise, the light source is determined to be unqualified. The data processing module 5 sends an alarm signal to the control module 6, and the control module 6 activates the alarm module 7.

[0064] To detect the color difference, the calculation method of the color difference ΔE is as follows:

[0065]

[0066] Among them, k i represents the i-th standard color card under the illumination of the light source 31 to be measured, r i represents the i-th standard color card under the illumination of the standard light source, U and V represent the chromaticity coordinates of the color sample, and W represents the lightness.

[0067] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method section.

[0068] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A detection method for a standard light source detection system, including a detection system and a detection method. The detection system includes a detection chamber (1), a detection table (2) installed in the detection chamber (1), and a light source module (3) installed at the top of the detection chamber (1) directly facing the detection table (2). The irradiation surface of the light source module (3) completely covers the area to be detected (21) on the detection table (2). An acquisition module (4), a data processing module (5), and a control module (6) are sequentially signal-connected in the detection chamber (1). The control module (6) is signal-connected to the light source module (3). The acquisition module (4) includes a light source detection sensor (41) installed in the area to be detected (21) and a reflected light detection sensor (42) installed in the detection chamber (1) and matching with the light source detection sensor (41). At least four light source detection sensors (41) are evenly installed around the area to be detected (21). An alarm module (7) is installed on the detection table (2), and the alarm module (7) is signal-connected to the control module (6). It is characterized in that: The detection method includes the following steps: Step 1: The system starts, and standard light source parameters are set, including the standard color temperature range, standard color rendering index range, standard spectral power distribution, and the spectral reflectance of the color card, and are stored in the data processing module (5). Step 2: The color temperature values Tc of each area in the area to be detected (21) are respectively detected by the light source detection sensor (41) and sent to the data processing module (5) to obtain the area with the weakest color temperature. Step 3: The data processing module (5) judges whether the color temperature value of the area with the weakest color temperature in Step 2 is within the standard color temperature range according to the set standard color temperature range of the standard light source. If so, go to Step 4; otherwise, it is determined that the light source to be tested (31) is unqualified, the data processing module (5) sends an alarm signal to the control module (6), and the control module (6) activates the alarm module (7). Step 4: The data processing module (5) processes the data of the reflected light of the area with the weakest color temperature measured by the reflected light detection sensor (42) in Step 3 to obtain the color rendering index Ra of the reflected light, and judges whether it is within the standard color rendering index range. If so, it is determined that the light source to be tested (31) is qualified; otherwise, it is determined that the light source to be tested (31) is unqualified. The data processing module (5) sends an alarm signal to the control module (6), and the control module (6) activates the alarm module (7).

2. The detection method for the standard light source detection system according to claim 1, It is characterized in that: The light source module (3) includes a light source to be tested (31) and a lampshade (32) sleeved around the light source to be tested (31). The cross-section of the lampshade (32) is a trapezoid with a smaller upper part and a larger lower part.

3. The detection method for the standard light source detection system according to claim 2, It is characterized in that: It further includes a remote control device signal-connected to the control module (6).

4. The detection method for the standard light source detection system according to claim 3, It is characterized in that: In the first step, at least five different sets of standard light source parameters are set, at least including D65 light source parameters, D50 light source parameters, CWF light source parameters, TL84 light source parameters, and UV light source parameters.

5. The detection method of the standard light source detection system according to claim 4, characterized in that: The specific steps of the fourth step are as follows: The reflected light detection sensor (42) detects the spectral wavelength λ of the reflected light in this area, and sends the spectral wavelength λ to the data processing module (5), which processes it to obtain the spectral power distribution S 1 (λ), and calculates the weight coefficient P for measuring the difference in spectral power distribution: Among them, S 1 (λ) is the spectral power distribution of the reflected light, S 2 (λ) is the standard spectral power distribution, R(λ) is the spectral reflectance of the color card, and P is the weight coefficient for measuring the difference in spectral power distribution; Calculate the special color rendering index R according to the weight coefficient P i : R i = 100 - 4.6 × ΔE × k × P Among them, ΔE is the color difference, k is the proportionality coefficient, P is the weight coefficient for measuring the difference in spectral power distribution, and R i is the special color rendering index; Calculate the color rendering index Ra of the reflected light: Among them, i represents the i-th standard color card, and R i is the special color rendering index; Compare the obtained general color rendering index Ra with the standard color rendering index range to determine whether it is within the standard color rendering index range. If it is, the light source is determined to be qualified; otherwise, the light source is determined to be unqualified. The data processing module (5) sends an alarm signal to the control module (6), and the control module (6) activates the alarm module (7).

6. The detection method of the standard light source detection system according to claim 5, characterized in that: The calculation method of the color difference ΔE is: Among them, k i represents the i-th standard color card under the illumination of the light source to be measured (31), r i represents the i-th standard color card under the illumination of the standard light source, U and V represent the chromaticity coordinates of the color sample, and W represents the lightness.

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