JP2018201087A - Device and method - Google Patents

Abstract

To solve such a problem that, in a phosphor type LED emitting light of a predetermined color by an LED and a phosphor, variations in color occur due to aging and manufacturing error.SOLUTION: In a device and a method, variations in color are highly accurately detected by detecting wavelength components of light emitted from a phosphor type LED by using a test patch.SELECTED DRAWING: Figure 10

Description

  The present invention relates to an apparatus and a method for detecting light source characteristics of an LED by reading irradiation light applied to an object using a phosphor type LED.

  2. Description of the Related Art Conventionally, there is a known problem that a color changes as a change with time associated with the use of a phosphor-type LED that emits light of a predetermined color by an LED and a phosphor. On the other hand, Patent Document 1 describes that information on the lifetime of a phosphor-type LED is acquired by reading a test patch of a color corresponding to the light of the phosphor.

Japanese Patent Laying-Open No. 2015-106762

  In the configuration described in Patent Document 1, the test patch is read in consideration of the temporal change of only the wavelength component of the phosphor among the LED and phosphor that are the base of the phosphor type LED configuration. Then, by performing parameter correction from the result, it is possible to extend the life of the LED.

  However, a change with time also occurs with respect to the wavelength component of the LED constituting the phosphor type LED. In addition, color variations occur not only due to changes over time but also due to LED manufacturing errors. With regard to this variation, manufacturers of phosphor-type LEDs can select the chromaticity rank by measuring the amount of light for each individual at the time of shipment. In such a case, there is a problem that the load is large.

  In view of such a problem, the present invention includes an LED that emits light of a first color, and a phosphor that emits light of a second color by the light of the first color from the LED. An apparatus for a reading apparatus that uses a light source to acquire a signal value by reading reflected light or transmitted light when the light source irradiates an object, wherein the reading apparatus emits light of the first color. A first signal value obtained by reading a first test patch for detection; a second signal value obtained by reading the second test patch for detecting light of the second color by the reading device; Based on the above, a correction parameter for correcting a signal value acquired by reading the object by the reading device is determined.

  With the above configuration, it is possible to detect the optical characteristics of the phosphor LED with higher accuracy by detecting the wavelength component of the light emitted by the phosphor LED.

Chromaticity coordinates that explain the rank of white LEDs and changes over time. The block diagram of the structure of a recording control part and a reading control part. FIG. 3 is a diagram illustrating a configuration of an image reading unit. Explanatory drawing of the spectral characteristic of white LED-1. The figure explaining the test patch output which white LED-1 irradiated. Explanatory drawing of the area | region read by a sensor among the test patch outputs which white LED-1 irradiated. The figure explaining the spectral characteristic of white LED-2, and the difference with white LED-1. The figure explaining the test patch output which white LED-2 irradiated. The figure explaining the area | region read by a sensor among the test patch outputs which white LED-2 irradiated. The flowchart judged in order to subdivide the initial color tone rank of white LED. The flowchart which judges the color tone change of white LED. The figure explaining the relationship between white LED rank determination and a correction table. The block diagram explaining the structure of the correction process part of white LED.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a white LED using a blue LED and a yellow phosphor will be described as an example of a phosphor type LED.

  FIG. 1 is a chromaticity coordinate for explaining the ranking and temporal change of white LEDs, and is an xy coordinate in the CIE chromaticity diagram. White LEDs are ranked because chromaticity changes due to manufacturing variations at the time of shipment. FIG. 1A shows the manufactured white LED divided into four ranks according to chromaticity. Similarly, FIG. 1B shows the white LED divided into eight ranks. Finer ranks increase accuracy, but increase manufacturing costs. For this reason, when an image reading apparatus is used for the purpose of detecting a color with high accuracy as in color calibration, it is common to use those that are finely ranked as shown in FIG. .

  In addition, the white LED has a problem that the color changes with time. FIG.1 (c) is a figure which shows an example of the time-dependent change of the color of white LED. As shown in the figure, the chromaticity changes with time. Then, after a certain amount of time has passed, the chromaticity changes to a rank different from the initial rank.

  FIG. 2 is a block diagram illustrating the configuration of the light source inspection apparatus according to this embodiment. FIG. 2A illustrates a recording control unit 101 that records an image on a recording medium, and FIG. 2B illustrates a reading control unit 102 that reads an object.

  The recording control unit 101 includes a data receiving unit 201, receives an image to be printed from outside the printing system, and generates print data. The recording control unit 101 of the present embodiment is an ink jet printer that forms an image by applying ink onto a recording medium from a recording head 206 that includes a plurality of ejection elements that eject ink. The data received by the data receiving unit 201 is stored in the recording memory 205, and the image processing unit 203 reads the data, performs image processing, and writes it again in another area of the recording memory 205. Then, the print control unit 204 reads the image-processed data from the recording memory 205, controls the recording head 206 based on the print timing sent from the position control unit 202, and records the image on the recording medium. A CPU 208 controls the entire recording control unit 101 according to software stored in the recording memory 205. Further, the CPU 208 performs message communication and the like with the reading control unit 102 via the communication I / F unit 207.

  The reading control unit 102 includes a CPU 301, a communication I / F unit 302, an image processing unit 303, and an image reading unit 304, and can access the storage memory 305. The CPU 301 controls the entire reading control unit 102 according to software stored in the storage memory 305. The reading unit 103 includes a light source 309, a lens 306, a color filter 307, a sensor 308, and light source rank information 310. As will be described later, in this embodiment, a white LED is used as the light source 309. The light source 309 irradiates the object (original) with light, and the lens 306 collects reflected light or transmitted light. The condensed light passes through the color filter 307 and is classified into light having a predetermined wavelength, and is recorded by the sensor 308. In this embodiment, among the red (R), green (G), and blue (B) filters, light from a green filter that transmits green light and light from a blue filter that transmits blue light are sensors 308. Is read. The amount of light received by the sensor 308 is stored in the storage memory 305 via the image reading unit 304 and then converted into a signal by the image processing unit 303. The light source rank information of the reading unit 103 is read by the reading control unit 102, and rank information is acquired. Further, message communication or the like is performed with the recording control unit 101 via the communication I / F unit 302.

  FIG. 3A is a diagram showing the structure of a white LED that is the light source 309. A blue LED 401 that emits blue light and a phosphor 402 that absorbs and excites part of the blue light from the blue LED and converts it into light of other wavelengths such as yellow are provided. In the present embodiment, a yellow phosphor that converts yellow light is used. And white light is implement | achieved by the blue light by blue LED, and the yellow light converted by the fluorescent substance.

  FIG. 3B illustrates the configuration of the reading unit 103. In this figure, light from a white LED, which is a light source 309, is diffused by a diffusion plate 403, and irradiates a recording material 404 on which a test patch is printed. Then, the reflected light reflected from the recording material enters the sensor 308 through a predetermined optical path. In the optical path, a mirror 405 for bending the light in a predetermined direction, a lens 306 for condensing the light, an infrared cut filter 406 for cutting unnecessary light, and for dividing the light into three channels. RGB color filter 307 is provided.

  Next, a method for detecting the color tone change of the white LED in the present embodiment will be described.

  FIG. 4 is a diagram showing the spectral characteristics of the white LED-1 used as the light source 309 in the present embodiment. FIG. 4A shows light from a blue LED light source and light from a phosphor, and FIG. 4B shows spectral characteristics as white LED-1. There are two peaks in the spectral characteristics of Fig. 4 (b). The narrow peak on the short wavelength side is caused by light from the blue LED light source, and the broad peak on the long wavelength side is converted from blue to yellow by the phosphor. Due to the emitted light.

  As for the short wavelength side (blue side) peak, the peak position is mainly caused by variations during production, and the peak size is caused by the influence of heat of the surrounding environment during use or change with time. As for the peak on the long wavelength side (yellow side), the wavelength is determined by the material of the phosphor and the coating amount, so that the peak position does not substantially change even if time elapses. On the other hand, the peak size decreases as the amount of light from the phosphor decreases.

  As described above, by obtaining the peak position and peak size on the short wavelength side, and the peak size on the long wavelength side, it is possible to detect variations and color tone changes during manufacture of the white LED.

  As a method for detecting the color tone change of the white LED, a method of executing calibration using the same chart from the initial use of the white LED is conceivable. This method is not problematic when the color of the chart does not change over time, but may be affected by changes over time such as the weather resistance of recording materials such as ink used for chart recording. For this reason, even if the calibration is executed using the same chart as the initial use of the white LED, when the color variation occurs, the color variation of the chart itself due to the color variation of the white LED or the change over time. It is difficult to determine if there is.

  Another possible method is to set the use time limit so that the white LED is replaced before the color change occurs. However, since the speed of color change varies depending on individual differences and the use environment temperature, it is necessary to set the replacement time so that it is replaced early with a margin. Therefore, it is difficult to set an appropriate time such as the set replacement time comes even if there is no problem in use.

  In contrast, in the present embodiment, a test patch formed by applying yellow ink and a test patch formed by applying magenta ink are newly generated each time. Using these test patches, the characteristics of the irradiation light when the white LED irradiates the test patch are estimated. Then, based on the estimated characteristics, a correction parameter for correcting the signal value obtained by reading the white LED is determined from among a plurality of correction parameter candidates.

  FIG. 10 is a flowchart for determining the color tone difference at the time of shipment of the white LED of the present embodiment. In step S <b> 1, the CPU 301 of the reading control unit 102 reads the shipping rank information of the white LEDs from the light source rank information 310 of the reading unit 103 via the image reading unit 304 and stores it in the storage memory 305. In step S2, the CPU 208 of the recording control unit 101 controls the position control unit 202 and the print control unit 204 to record the test patch-1 on the recording medium. This test patch-1 is a yellow pattern recorded using yellow ink. In step S <b> 3, the image reading unit 304 of the reading control unit 102 reads the test patch- 1, acquires a read signal value, and stores it in the storage memory 305. In step S4, the CPU 208 of the recording control unit 101 controls the position control unit 202 and the print control unit 204 to record the test patch-2 on the recording medium. The test patch-2 is a magenta pattern recorded using magenta ink. In step S <b> 5, the image reading unit 304 of the reading control unit 102 reads the test patch-2, acquires a read signal value, and stores it in the storage memory 305. In step S6, the rank information saved in the storage memory 305, the read signal value saved in step S3, and the read signal value saved in step S5 are acquired. Then, the CPU 301 and the image processing unit 303 are used to compare with a plurality of threshold values stored in advance, determine between which threshold the read signal value exists, and rank the white LED together with the rank information. Sort finely. In step S7, a correction parameter to be applied is determined based on the rank classified in step S6. After the correction parameter is determined, the correction parameter is applied to the image processing unit 303 of the reading control unit 102, and then a density difference, a chromaticity difference, and the like due to a discharge amount variation of each nozzle of the recording head 206 of the recording control unit 101 are determined. Print the pattern to be measured. By reading this pattern, it is possible to generate a print head color correction pattern and the like in consideration of the chromaticity rank of the white LED.

  If this flow is applied, it becomes possible to classify the white LEDs shipped in the rank classification of FIG. 1A finely as shown in FIG. 1B. As a result, the shipping rank is roughly classified, and the classification is performed in more detail in the main body, so that chromaticity correction with high accuracy can be performed for the chromaticity variation of the white LED.

  FIG. 11 is a flowchart for determining the color tone difference due to the temporal change of the white LED of the present embodiment. In step S <b> 1, the CPU 301 of the reading control unit 102 reads the shipping rank information of the white LEDs from the light source rank information 310 of the reading unit 103 via the image reading unit 304 and stores it in the storage memory 305. In step S2, the CPU 208 of the recording control unit 101 controls the position control unit 202 and the print control unit 204, and a yellow pattern using yellow ink as a test patch-1 is formed on the recording medium, as in the flowchart of FIG. Record. In step S <b> 3, the image reading unit 304 of the reading control unit 102 reads the test patch- 1, acquires a read signal value, and stores it in the storage memory 305. In step S4, the read signal value stored in step S3 is acquired and compared with a plurality of threshold values stored in advance using the CPU 301 and the image processing unit 303, and the read signal value exists within the currently set rank. Determine whether. If it does not exist in the rank, it is determined to which rank the current reading value corresponds, and a corrected rank -1 is newly determined in the subsequent step. In subsequent steps S5, S6, and S7, in the same manner as in S1 to S3, this time, a magenta pattern using magenta ink is recorded as test patch-2, read, and it is determined whether the read value is within the value specified by the rank. . If it is not within the prescribed value, the correction rank-2 is determined based on the read signal value in the subsequent step. In step S8, the correction parameter to be applied is determined based on the information on the correction rank-1 and the correction rank-2. At this time, if neither correction rank-1 nor correction rank-2 has changed, no correction is necessary, and if any rank of correction rank-1 or correction rank-2 has changed, it corresponds to the change. The correction parameter to be determined is determined. A method for determining the correction parameter will be described later with reference to FIG. By applying the determined correction parameter to the image processing unit 303, the reading control unit 102 can read the print head color correction pattern in consideration of the temporal change of the white LED. The determined correction rank and the corresponding correction parameter are stored in the storage memory 305. Then, when executing a process for determining a color tone difference due to a change with time, the correction rank stored in the storage memory 305 is read and it is determined whether or not the correction rank is the same as the previously determined correction rank. The determined correction rank may be stored in the light source rank information 310 of the reading unit 103 and read when the next process is executed.

  Here, the determination method of the correction parameter in steps S6 and S7 in FIG. 10 and step S8 in FIG. 11 will be described with reference to FIG. FIG. 12A is a diagram illustrating the XY chromaticity coordinates of the white LED, and FIG. 12B is a diagram illustrating a change in spectral characteristics of the white LED. When the white LEDs are classified into 16 ranks, 1201 in FIG. 12A and 1203 in FIG. 12B, the shift of the peak position on the short wavelength side, and 1202 in FIG. 12A and FIG. The peak amount on the long wavelength side indicated by 1204 in FIG. Therefore, the peak amount on the long wavelength side is measured using a yellow test patch and a blue filter, and the peak position on the short wavelength side is measured using a magenta test patch and a green filter.

  FIG. 12C is a table for determining correction parameters to be applied to the image processing unit 303 of the reading control unit 102 based on the output value (B value) of the blue filter and the output value (G value) of the green filter. It is. Here, the output value (B value) of the blue filter is compared with threshold values T1, T2, and T3 defined in advance, and the output value (G value) of the green filter is compared with a predetermined threshold value U1. , U2, U3. Then, based on each value, a lookup table (LUT) to be applied to the image processing unit 303 of the reading control unit 102 is determined from LUT0, 1,. By applying the determined LUT to a storage memory that is read by the color space conversion unit of the image processing unit 303 illustrated in FIG. 13, chromaticity due to variations and fluctuations in white LEDs is corrected and output as a standard color space. Is possible. With such a configuration, it is possible to perform chromaticity correction with high accuracy against chromaticity variations of white LEDs. Although the peak amount on the short wavelength side also affects the rank classification, when the peak amount on the short wavelength side varies, the peak amount on the long wavelength side that outputs the blue LED light via the phosphor also varies. For this reason, if the shift of the peak position on the short wavelength side and the peak amount on the long wavelength side are detected, it is possible to detect fluctuations in the peak amount on the short wavelength side.

  Next, test patches used in the present embodiment will be described with reference to FIG. In the present embodiment, a yellow test patch provided with an ink (recording material) containing a yellow color material on a special paper having an ink receiving layer formed on its surface, such as glossy paper, and a magenta color material are included. A magenta test patch provided with ink (recording material) is used. FIG. 5A is a diagram illustrating the relationship between the spectral reflectance of the white LED-1 and the yellow test patch. The grayed out area is an area that indicates a signal value obtained by reading the reflected light that the white LED-1 has applied to the test patch. Similarly, FIG. 5B is a diagram showing the relationship between the spectral reflectances of the white LED-1 and the magenta test patch, and the grayed out portion is the reflection of the white LED-1 irradiating the test patch. This is a region indicating a signal value obtained by reading light by a sensor.

  FIG. 6A shows the relationship of the spectral transmittance of the blue filter included in the reading control unit 102 in addition to FIG. 5A. As shown in FIG. 6A, by reading a yellow test patch with a blue filter, a filter having sensitivity at the peak portion (near 560 nm) of the crossed net pattern portion to be detected can be realized. . Similarly, FIG. 6B shows the relationship of the spectral transmittance of the green filter included in the reading control unit 102 in addition to FIG. 5B. As shown in FIG. 6B, by reading the magenta test patch with a green filter, it is possible to realize a filter having sensitivity at the peak portion (around 450 nm) of the crossed net pattern portion to be detected. .

  The yellow and magenta test patches of the present embodiment are provided with an ink amount that is approximately the same as the amount that the recording medium can accept per unit area, and at an application amount that provides at least a surface coverage of 100% or more. is there. Note that x is one side of a predetermined unit area (square), S is the area of dots formed on the recording medium when one ink droplet is applied on the recording medium, and the number of ink droplets applied per unit area is S It is assumed that the surface coverage is 100% or more when x2 ≦ S × n. That is, the surface coverage of 100% indicates that the recording medium is covered with ink.

  For example, when converted using a 600 dpi lattice, x = 40 μm, so the unit area is 40 × 40 = 1.6 × 10 ^ −9 (m ^ 2). On the other hand, the area S of a dot having a diameter of 40 μm is S = 1.25 × 10 ^ −9 (m ^ 2). Therefore, the number of dots with a surface coverage of 100% is the unit area divided by the area of the dots, and n = 1.28. In the present embodiment, a test patch to which ink droplets are applied so that n = 3 is used so that the surface is sufficiently covered in consideration of deviations in the landing positions of dots.

  In the present embodiment, it is preferable to use a test patch to which an ink amount having a surface coverage of 100% or more is applied. This is due to the following reasons.

  In the ink jet recording apparatus used in the present embodiment, the ink lands on the recording medium, spreads in a circle having a predetermined bleeding rate determined by the recording medium and the ink, and permeates the recording medium. A recording medium such as glossy paper has an ink receiving layer composed of fine gaps, and the ink penetrates into the gaps. Further, the color material in the ink and the recording medium are adsorbed with a predetermined adsorption amount, and the distribution of the color material in the depth direction of the recording medium is determined. The amount of adsorption is determined by the color material and the recording medium. The weaker the adsorption, the deeper the color material penetrates in the depth direction. When a large amount of ink is applied to the recording medium, the ink penetrates deeper and is adsorbed. However, the only color material that actually contributes to color development is the color material distributed near the surface. Therefore, when the ink application amount is small, almost all of the color material contributes to color development, and the change in the density value or colorimetric value of the printed matter accompanying the change in the ink amount is large. On the other hand, when the amount of applied ink is large, the color material that does not contribute to color development increases, and even if the amount of ink increases, changes in density values and colorimetric values are small.

  In a general ink jet recording apparatus, the amount per ink droplet ejected from the ink ejection section varies or varies. Due to the variation in the ejection amount, even if the same number of ink droplets are applied on the recording medium, the total ink application amount differs. For this reason, when the ink application amount is different, the spectral reflection characteristics of the printed matter are also different. However, as described above, when using a test patch to which an ink amount with a surface coverage of 100% or more is used, the overflowed ink is adsorbed in the deep part of the recording medium and does not contribute to color development. The change in the spectral reflectance of the ink application amount due to the ink hardly needs to be considered.

  FIGS. 7A and 7B show the spectral characteristics of the white LED-1 and, as an example, the spectral characteristics of the white LED-2 when the color tone is shifted due to variations at the time of shipment. It can be seen that due to the manufacturing variation, the peak position of the wavelength of the blue LED on the short wavelength side is shifted, and the peak of the phosphor on the long wavelength side is increased.

  FIGS. 8A and 8B are diagrams showing the reflectance when the white LED-2 shown in FIG. 7 is irradiated to the test patch created by applying the yellow ink and the magenta ink described above. is there. As shown in the figure, a difference in reflectance occurs when white LED-1 is used. FIG. 9 shows the relationship between the spectral transmittance of the blue and green filters of the reading control unit 102 in addition to FIG. By reading the yellow test patch with the blue filter and the magenta test patch with the green filter, it is possible to read the reflected peak wavelength component.

  Note that when it is determined that the rank variation of the white LED has occurred based on the amount of change in the signal value, the determination result may be notified to the user. For example, the recording control unit 101 or the reading control unit 102 includes a not-illustrated notification unit, and notifies the information indicating that the white LED needs to be replaced based on the determination result. Further, it may be a notification for at least one of the fluctuation amount of the signal value obtained by reading the yellow test patch and the signal value obtained by reading the magenta test patch, and information for prompting the change of the correction parameter is notified. It may be a thing.

  As described above, in the present embodiment, the recording medium on which the test patch is formed by applying the yellow light to the irradiation light from the white LED including the blue LED and the yellow phosphor, and the magenta ink are applied. To irradiate the recording medium on which the test patch is formed. Then, the reflected light from the test patch is read using a blue filter and a green filter. Then, based on the signal value read using the blue filter and the signal value read using the green filter, the spectral distribution characteristic of the white LED is estimated, and the reading correction parameter of the sensor is determined. Thereby, the dispersion | distribution of the spectral distribution characteristic of white LED can be correct | amended, and it becomes possible to read an image with higher precision. In addition, since there is no need to set the replacement time early with a sufficient margin, including differences due to individual differences and usage environment differences, it is possible to determine whether or not white LEDs need to be replaced, and replace them appropriately. The time can be estimated.

  In the present embodiment, a description has been given using a blue LED that emits blue light and a white LED that includes a phosphor that converts blue light into yellow light. The present invention is not limited to the above embodiment as long as it is a phosphor type LED that can emit light of a predetermined color by using the LED and the phosphor. Any device that emits light having a wavelength in the visible light region including wavelengths of 400 nm to 700 nm may be used. For example, what comprises LED which emits purple light instead of blue light may be used.

  In addition, the test patch formed using only the yellow ink of the present embodiment is not limited to the above patch as long as it is a patch that can detect the fluctuation of the peak on the long wavelength side of the irradiation light of the phosphor type LED. Alternatively, ink of a color other than yellow ink may be applied. Further, the test patch formed using only the magenta ink according to the present embodiment is not limited to the above patch as long as it is a patch that can detect the fluctuation of the peak on the short wavelength side of the irradiation light of the phosphor type LED. Alternatively, ink of a color other than magenta ink may be applied. Further, the recording material for recording the test patch is not limited to ink. For example, a test patch recorded with toner applied by an electrophotographic recording method may be used. As described above, when the color of the test patch does not change with time, it is not necessary to generate a new test patch each time. Further, if the fluctuation of the peak position and peak amount on the short wavelength side of the irradiation light of the white LED and the fluctuation of the peak amount on the long wavelength side can be detected, the light may not be reflected light of the recording medium but may be transmitted light. In the case of inspecting only the variation of the blue LED constituting the white LED at the time of shipment of the white LED, it is not necessary to see both the two peaks in the spectral characteristics of the white LED. Only the wavelength peak of light from the blue LED on the short wavelength side needs to be detected using a magenta patch and a green filter.

  In the present embodiment, the sensor reading value is acquired as information indicating the characteristics of the irradiation light. However, instead of the sensor, the spectral distribution characteristic of the reflected light of the test patch is measured using a spectral intensity meter. The form to acquire may be sufficient. In this case, in the initial use of the white LED, a test patch that can detect the peak position and peak amount of the short wavelength of the irradiation light of the white LED and the peak amount of the long wavelength is recorded, and the result measured by the spectral intensity meter Is stored in a nonvolatile storage memory. Then, after a certain period of time has elapsed, a similar test patch is measured to obtain a spectral distribution characteristic, and the rank of the white LED can be obtained by comparing with the stored measurement result.

101 Recording control unit 102 Reading control unit 103 Reading unit

Claims (19)

A light source including an LED that emits light of a first color and a phosphor that emits light of a second color by the light of the first color from the LED, and the light source irradiates an object A device for a reading device that acquires a signal value by reading reflected light or transmitted light when
A first signal value obtained by reading the first test patch for detecting light of the first color by the reading device, and a second value for detecting light of the second color by the reading device. An apparatus for determining a correction parameter for correcting a signal value acquired by the reading device reading an object based on a second signal value obtained by reading a test patch.   The apparatus according to claim 1, wherein the reading device corrects a signal value obtained by reading an object using the determined correction parameter.   The apparatus according to claim 1, wherein the correction parameter is determined from a plurality of correction parameter candidates.   The rank of the light source is determined based on the first signal value and the second signal value, and the correction parameter corresponding to the rank is determined. The device according to item.   The apparatus according to claim 4, wherein a rank previously determined or a rank at the time of shipment is acquired, and the correction parameter is further determined based on the rank.   The apparatus according to claim 1, wherein the apparatus notifies the user of information regarding the determined correction parameter.   The apparatus according to claim 6, wherein the information is information indicating that the light source needs to be replaced.   The apparatus according to claim 1, wherein the light source is a white LED.   The apparatus according to claim 1, wherein the first color light is blue light and the second color light is yellow light.   The apparatus according to claim 1, wherein the first test patch is a patch recorded using a magenta recording material.   The apparatus according to claim 1, wherein the first signal value is read using a filter that transmits green light.   The apparatus according to claim 1, wherein the second test patch is a patch recorded using a yellow recording material.   The apparatus according to any one of claims 1 to 12, wherein the second signal value is read using a filter that transmits blue light.   The apparatus according to any one of claims 1 to 13, further comprising recording means for recording the first test patch and the second test patch. A light source including an LED that emits light of a first color and a phosphor that emits light of a second color by the light of the first color from the LED, and the light source irradiates an object A device for a reading device that acquires a signal value by reading reflected light or transmitted light when
A first signal value obtained by reading the first test patch for detecting light of the first color by the reading device, and a second value for detecting light of the second color by the reading device. An apparatus for notifying information on the light source based on a second signal value obtained by reading a test patch.   The apparatus according to claim 15, wherein the information is information indicating that the light source needs to be replaced.   The apparatus according to claim 15, wherein the information is information related to a variation amount of the first signal value or the second signal value. A light source including an LED that emits light of a first color and a phosphor that emits light of a second color by the light of the first color from the LED, and the light source irradiates an object A device for a reading device that acquires a signal value by reading reflected light or transmitted light when
An apparatus for inspecting the color of the LED by obtaining a signal value obtained by reading a test patch for detecting light of the first color by the reading apparatus. A light source including an LED that emits light of a first color and a phosphor that emits light of a second color by the light of the first color from the LED, and the light source irradiates an object A method for a reading device for obtaining a signal value by reading reflected light or transmitted light when
A first signal value obtained by reading the first test patch for detecting light of the first color by the reading device, and a second value for detecting light of the second color by the reading device. A method for determining a correction parameter for correcting a signal value acquired by the reading device reading an object based on a second signal value obtained by reading a test patch.

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