stimulus value direct reading colorimeter
By employing multiple color sensing units in a stimulus value direct-reading colorimeter and adding the signal from the second color sensing unit in the signal processing circuit, the problem of increased noise in low-brightness areas is solved, and high-precision color measurement is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KONICA MINOLTA INC
- Filing Date
- 2024-09-13
- Publication Date
- 2026-07-24
AI Technical Summary
Existing direct-reading colorimeters with stimulus values experience increased noise in low-brightness regions, affecting measurement accuracy, especially due to increased noise components caused by wiring and signal switching of the light receiving sensor.
Multiple color sensing units are employed, including a first color sensing unit, a second color sensing unit, and a third color sensing unit, each having a spectral sensitivity corresponding to the X, Y, and Z components. The signal from the second color sensing unit is processed in the signal processing circuit and then added in the arithmetic unit, thereby reducing signal switching, shortening wiring, and suppressing noise.
High-precision color measurement was achieved in low-brightness regions, and the accuracy of the measurement was improved by reducing noise components and individual biases.
Smart Images
Figure CN122459656A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a colorimeter with direct reading of stimulus values. Background Technology
[0002] The stimulus value direct-reading colorimeter has multiple color sensing units. Each color sensing unit has a color filter and a light receiving sensor, which receives light transmitted through the color filter. The multiple color sensing units respectively have spectral sensitivities corresponding to the X component of the color matching function, the Y component, and the Z component.
[0003] As is well known, the sensitivity of a rod is higher than that of a cone, therefore, at low brightness levels, luminance differences are more significant than chromaticity differences. Thus, in direct-reading colorimeters, luminance measurement performance should be prioritized over chromaticity measurement performance in the low-brightness region. In other words, the spectral sensitivity corresponding to the Y component of the color matching function should be higher than the spectral sensitivity corresponding to the X component and the Z component.
[0004] Therefore, in order to improve the spectral sensitivity corresponding to the Y component, it is advisable to add a color sensing unit with spectral sensitivity corresponding to the Y component.
[0005] In Patent Document 1, in the third mode of the second embodiment, the output of the light receiving sensor 6b for detecting the Y value and the output of the light receiving sensor 6d for flicker measurement are added together and input to the amplifier (integrator) 7b of the circuit for detecting the Y value. That is, in Patent Document 1, the color sensing unit having spectral sensitivity corresponding to the Y component is additionally equipped with an amount corresponding to the light receiving sensor 6d for flicker measurement. Therefore, the spectral sensitivity corresponding to the Y component of the color matching function is higher than the spectral sensitivity corresponding to the X component and the spectral sensitivity corresponding to the Z component.
[0006] Patent Document 1: Japanese Patent No. 6794995 Summary of the Invention
[0007] However, in the technology described in Patent Document 1, the output of the light receiving sensor 6b used for detecting the Y value and the output of the light receiving sensor 6d used for flicker measurement are input to the integrator 7b of the circuit used for detecting the Y value. In other words, since the outputs of the two light receiving sensors are added together before being input to the integrator 7b of the circuit used for detecting the Y value, the following disadvantage exists.
[0008] In other words, in low-brightness regions, the wiring from the light-receiving sensor to the integrator should be as short as possible to detect weak light. This is because longer wiring increases parasitic capacitance, raises concerns about crosstalk, and may also lead to leakage due to humidity. These become noise components, thus reducing measurement accuracy.
[0009] However, when the summation of the outputs of multiple optical receiving sensors is performed before being input to the integrator (amplifier), as described in Patent Document 1, the wiring becomes longer and generates noise components because the outputs of each optical receiving sensor need to be switched. Furthermore, the circuit noise caused by the switching of the outputs of each optical receiving sensor also increases. Therefore, compared to the case where the outputs of the optical receiving sensors are directly input to the integrator, there is a problem of increased noise.
[0010] The purpose of this invention is to provide a direct-reading colorimeter that can suppress noise even when it has multiple color sensing units with spectral sensitivity corresponding to the Y component.
[0011] The above objectives are achieved through the following means.
[0012] (1) A stimulus value direct-reading colorimeter, comprising: Multiple color sensing units are provided, each having multiple color filters and multiple light receiving sensors, wherein the multiple light receiving sensors receive light transmitted through each color filter; Multiple signal processing circuits, corresponding to each of the multiple color sensing units, and receiving signals from each color sensor, have integration capabilities; and The arithmetic unit performs calculations on the outputs from the plurality of signal processing circuits. The plurality of color sensing units include: a first color sensing unit having a spectral sensitivity corresponding to the X component of the color matching function; a second color sensing unit having a spectral sensitivity corresponding to the Y component; and a third color sensing unit having a spectral sensitivity corresponding to the Z component. There are multiple second color sensing units. After each signal from the plurality of second color sensing units is processed in its respective signal processing circuit, it is added together in the arithmetic unit.
[0013] (2) In the stimulus value direct reading colorimeter described in item 1 above, the total area of the plurality of light receiving sensors constituting the plurality of second color sensing units is greater than the area of each light receiving sensor constituting the first color sensing unit and the third color sensing unit.
[0014] (3) In the direct-reading colorimeter for stimulus values described in paragraph 1 or 2 above, a signal processing circuit includes an integrator, an A / D converter and a filter, and multiple signal processing circuits are composed of a single semiconductor chip.
[0015] (4) In the stimulus value direct reading colorimeter described in item 1 or 2 above, a light guide is provided, which guides the light of the object being measured to a plurality of the color sensing units respectively.
[0016] (5) In the direct-reading colorimeter for stimulus values described in item 4 above, the light guide is formed of an optical fiber.
[0017] (6) In the stimulus value direct reading colorimeter described in item 5 above, light in the incident area located at a point symmetrical about the optical axis in the incident surface of the optical fiber into which the light from the object being measured is incident is guided to each of the color sensing units.
[0018] (7) In the direct-reading colorimeter for stimulus values described in item 5 above, the light receiving sensor is composed of a Si photodiode.
[0019] The stimulus value direct-reading colorimeter of the present invention includes: a plurality of color sensing units having a plurality of color filters and a plurality of light receiving sensors receiving light transmitted through each color filter; a plurality of signal processing circuits corresponding to each of the plurality of color sensing units and receiving signals from each color sensing unit, and having an integration function; and an arithmetic unit performing calculations on the outputs from the plurality of signal processing circuits. The plurality of color sensing units include: a first color sensing unit having a spectral sensitivity corresponding to the X component of a color matching function; a second color sensing unit having a spectral sensitivity corresponding to the Y component; and a third color sensing unit having a spectral sensitivity corresponding to the Z component. Additionally, there are a plurality of second color sensing units.
[0020] Furthermore, the signals from the multiple second color sensing units are processed in their respective signal processing circuits and then added in the arithmetic unit. In other words, the signals from the second color sensing units, which have spectral sensitivity corresponding to the Y component, are not added before being input to the integrator as in the past, but rather added in the arithmetic circuit after being input to and processed by the signal processing circuit. Therefore, there is no need to switch signal inputs when the signals from each second color sensing unit are input to the signal processing circuit, resulting in shorter wiring between the second color sensing units and the signal processing circuit, and suppression of noise components. Moreover, circuit-related noise caused by input switching of signals from the second color sensing units is eliminated. As a result, noise is suppressed, enabling high-precision color measurement in low-brightness regions. Attached Figure Description
[0021] Figure 1This is a block diagram illustrating the construction of a colorimeter as an example of a stimulus value direct-reading colorimeter, which is an embodiment of the present invention.
[0022] Figure 2 This diagram schematically shows the dimensions of each light-receiving sensor in the first to third color sensing units.
[0023] Figure 3 It is a front view of the incident surface of the optical fiber bundle, and a diagram used to illustrate the relationship between the input light and the light guided to the color sensing unit in the eight incident areas of the incident surface.
[0024] Figure 4 It is also a front view of the incident surface of the optical fiber, and a diagram used to illustrate the relationship between the input light in the four incident areas of the incident surface and the light guided to the color sensing unit.
[0025] Figure 5 It is a schematic diagram showing a light beam with a circular cross-section that exits from a point in the measured area and enters the incident surface of the fiber bundle.
[0026] Figure 6 It is a diagram that schematically shows the state in which the upward-facing beam of light emitted from the object being measured is larger than the downward-facing beam.
[0027] Figure 7 This diagram illustrates the effect of setting up multiple second color sensing units with spectral sensitivity corresponding to the Y component, and it shows the case of receiving light without a condenser lens.
[0028] Figure 8 This diagram illustrates the effect of setting up multiple second color sensing units with spectral sensitivity corresponding to the Y component, and it is a diagram of the receiving situation with a condenser lens.
[0029] Figure 9 In order to explain Figure 8 The diagram shows the state when the area of the light receiving sensor is increased to twice its original size. Detailed Implementation
[0030] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0031] Figure 1 This is a block diagram showing the construction of a colorimeter 1, which is an example of a stimulus value direct-reading colorimeter related to one embodiment of the present invention.
[0032] like Figure 1 As shown, the color luminance meter 1 includes: an objective lens 2, a field of view aperture 3, an optical fiber bundle 4, multiple (four in this example) color sensing units 51 to 54, four signal processing circuits 61 to 64, and an arithmetic unit 7.
[0033] Each color sensing unit 51 to 54 has a color filter 511 to 541 and a light receiving sensor 512 to 542.
[0034] The color sensing unit 51 is a first color sensing unit and includes: a first color filter 511; and a first light receiving sensor 512 that receives light passing through the first color filter 511. The first color sensing unit 51 has a spectral sensitivity corresponding to the X component of the color matching function.
[0035] Color sensing units 52 and 53 are second color sensing units, and each has: second color filters 521 and 531; and second light receiving sensors 522 and 532, which receive light passing through each of the second color filters 521 and 531. Both second color sensing units 52 and 53 have spectral sensitivity corresponding to the Y component of the color matching function.
[0036] The color sensing unit 54 is a third color sensing unit and includes: a third color filter 541; and a third light receiving sensor 542 that receives light passing through the third color filter 541. The third color sensing unit 54 has a spectral sensitivity corresponding to the Z component of the color matching function.
[0037] In this embodiment, such as Figure 2 As illustrated, the light receiving sensor 512 of the first color sensing unit 51, the light receiving sensors 522 and 532 of the second color sensing units 52 and 53, and the light receiving sensor 542 of the third color sensing unit 54 all use sensors of nearly the same size. Therefore, the combined area of the light receiving sensors 522 and 532 of the second color sensing units 52 and 53 becomes approximately twice the area of each of the light receiving sensors 512 of the first color sensing unit 51 or the light receiving sensor 542 of the third color sensing unit 54.
[0038] In this embodiment, each of the light receiving sensors 512 to 542 is composed of a Si photodiode with high receiving sensitivity and fast response time, but is not limited to a Si photodiode.
[0039] In addition, a condenser lens can be provided in front of each color filter 511 to 541 in the color sensing units 51 to 54.
[0040] Each signal processing circuit 61 to 64 has: integrators 611 to 641; A / D converters 612 to 642 that convert analog signals from integrators 611 to 641 into digital signals; and filters 613 to 643 that remove noise contained in the signals from A / D converters 612 to 642.
[0041] Four signal processing circuits 61-64 correspond to the four color sensing units 51-54 (first to third), and the signal from the light receiving sensor 512 of the first color sensing unit 51 is input to the integrator 611 of the signal processing circuit 61. The signals from the light receiving sensors 522 and 532 of the second color sensing units 52 and 53 are input to the integrators 621 and 631 of the signal processing circuits 62 and 63, respectively. The signal from the light receiving sensor 542 of the third color sensing unit 54 is input to the integrator 641 of the signal processing circuit 64.
[0042] The outputs of the four signal processing circuits 61 to 64 are input to the arithmetic unit 7.
[0043] The arithmetic unit 7 performs calculations on the measured values based on the outputs from the signal processing circuits 61 to 64, and also performs overall control of the color luminance meter 1. It is composed of a processor such as a CPU. Regarding the two second color sensing units 52 and 53, after the arithmetic unit 7 adds the signals output from the signal processing circuits 62 and 63, the arithmetic unit 7 calculates the measured values based on the summed values.
[0044] In this embodiment, although not limited to this, the four signal processing circuits 61-64 are composed of a single semiconductor chip 8 that has undergone the same semiconductor process. The reason for this will be explained later.
[0045] The fiber bundle 4 is formed by binding together a plurality of optical fibers. The fiber bundle 4 functions as a light guide, directing the measurement light to each of the four color sensing units 51-54. The end of the fiber bundle 4 on the objective lens 2 side is bound together, forming the incident surface of the measurement light. Within the fiber bundle 4, it is split into four branches 41-44 from a midway point downstream of the incident surface. The exit ends 411-441 of each of the four branches 41-44 extend to the relative positions of the color filters 511-541 of each color sensing unit 51-54. With this configuration, the measurement light incident on the incident surface of the fiber bundle 4 is split into four branches 41-44 and guided to the exit ends 411-441, exiting from the exit ends 411-441 and incident on each color sensing unit 51-54.
[0046] Next, for Figure 1 The operation of the color luminance meter 1 shown will be explained.
[0047] The beam of light 100 to be measured is converged by objective lens 2. The objective lens optics system consisting of objective lens 2 can be replaced with other types of objective lens optics systems.
[0048] The peripheral portion of the converged light beam 101 is restricted by the field stop 3.
[0049] The constrained light beam is incident on the incident surface of the fiber bundle 4. The incident light beam is branched by branches 41 to 44. The four light beams obtained by the branches are emitted from the exit ends 411 to 441 of the branches 41 to 44, respectively. Alternatively, the branching mechanism of the fiber bundle 4 can be replaced with other types of branching mechanisms.
[0050] Light beams emitted from the emission ends 411-441 of the four branches 41-44 are respectively input to color sensing units 51-54 and pass through the color filters 511-541 of each color sensing unit 51-54. Each light beam is received at a light receiving sensor 512-542 of each color sensing unit 51-54. Each light receiving sensor 512-542 outputs an electrical signal corresponding to the received light beam.
[0051] Furthermore, the relative spectral responsivity achieved by the color filter 511 and light receiving sensor 512 of the first color sensing unit 51 is approximated as the X component of the color matching function. The relative spectral responsivity achieved by the color filters 521 and 531 of the two second color sensing units 52 and 53, and the light receiving sensors 522 and 532, is also approximated as the Y component of the color matching function. The relative spectral responsivity achieved by the color filter 541 and light receiving sensor 542 of the third color sensing unit 54 is approximated as the Z component of the color matching function.
[0052] The electrical signals from each optical receiving sensor 512-542 are input to the integrators 611-641 of the corresponding signal processing circuits 61-64 and integrated. The integrated electrical signals are then converted from analog to digital by the corresponding A / D converters 612-642.
[0053] Each signal after digital conversion is filtered by corresponding filters 613 to 643 to remove noise, and then input to the arithmetic unit 7.
[0054] The arithmetic unit 7 calculates the stimulus value X based on the signal value from the signal processing circuit 61. The arithmetic unit 7 adds the two signal values from the signal processing circuits 62 and 63, and calculates the brightness value Lv (stimulus value Y) based on the addition result. The arithmetic unit 7 calculates the stimulus value Z based on the signal value from the signal processing circuit 64.
[0055] In this way, the luminance value Lv (stimulus value Y) is obtained by adding the signals after the outputs of the light receiving sensors 522 and 532 of the two color sensing units 52 and 53 have been processed by the signal processing circuits 62 and 63 in the calculation unit 7. Furthermore, the total area of the light receiving sensors 522 and 532 of the color sensing units 52 and 53 is approximately twice that of the case where there is only one light receiving sensor. Additionally, the area of the light receiving sensors 512 and 542 of the other color sensing units 51 and 54 is also approximately twice that of the light receiving sensors 512 and 542. Therefore, the amount of light received in the low-brightness region based on the two light receiving sensors 522 and 532 can be increased, and the signal value used to calculate the luminance value Lv (stimulus value Y) can also be increased. As a result, high-precision color measurement can be achieved.
[0056] Furthermore, since the outputs of the two second color sensing units 52 and 53 corresponding to the spectral sensitivity of the Y component are processed by the signal processing circuits 62 and 63 respectively, and then added in the arithmetic unit 7, the following effect is obtained.
[0057] That is, compared to the case where the outputs of the two second color sensing units 52 and 53 are added before being input to the signal processing circuits 62 and 63, input switching of signals from each of the second color sensing units 52 and 53 is not required. Therefore, each of the second color sensing units 52 and 53 and each of the signal processing circuits 62 and 63 can be connected in the shortest possible way. As a result, the wiring between the second color sensing units 52 and 53 and the signal processing circuits 62 and 63 can be shortened, and noise components can be suppressed. Moreover, circuit-related noise caused by input switching of signals from the second color sensing units 52 and 53 is not generated. As a result, noise is suppressed, and high-precision color measurement can be achieved in low-brightness areas.
[0058] Furthermore, in this embodiment, the four signal processing circuits 61 to 64 are composed of a single semiconductor chip 8, which also has the following advantages.
[0059] That is, when the four signal processing circuits 61 to 64 are formed from separate semiconductor chips (in the discrete case), each signal processing circuit 61 to 64 is manufactured by a separate process, so the individual deviations, such as the batch deviations, are large.
[0060] In contrast, in this embodiment, the integrators 611 to 641, the A / D converters 612 to 642, and the filters 613 to 643 of each signal processing circuit 61 to 64 are manufactured using the same semiconductor process. Therefore, when the signal from signal processing circuit 62 is equivalent to the signal from signal processing circuit 63, the difference between these signal values is smaller. Thus, compared to the case where signal processing circuits 62 and 63 are formed from separate semiconductor chips, the individual deviation of the output after adding the two signal values, or the individual deviation of the variation caused by temperature characteristics, is reduced. Therefore, higher accuracy color measurement can be achieved in low-brightness regions.
[0061] Furthermore, in this embodiment, the branches 41 to 44 of the fiber bundle 4 are configured as described below.
[0062] That is, such as Figure 3 As shown, the incident surface A of the fiber bundle 4 is divided into eight sector-shaped incident regions A11, A12, A21, A22, A31, A32, A41, and A42, each with a central angle of 45 degrees and an area of equal size. According to Figure 3 It can be seen that incident regions A11 and A12, incident regions A21 and A22, and incident regions A31 and A32 are located at point-symmetric positions centered on the optical axis 40 (the center of the incident surface A). The light beams incident on these two incident regions located at point-symmetric positions are guided to a color sensing unit via a branch and exit from the exit end of the branch.
[0063] That is, the light beams incident on incident regions A11 and A12 are guided by branch 41 to the first color sensing unit 51, and exit from the exit end 411 of branch 41 to the color filter 511 of the first color sensing unit 51. The light beams incident on incident regions A21 and A22 are guided by branch 42 to the second color sensing unit 52, and exit from the exit end 421 of branch 42 to the color filter 521 of the second color sensing unit 52. The light beams incident on incident regions A31 and A32 are guided by branch 43 to the second color sensing unit 53, and exit from the exit end 431 of branch 43 to the color filter 531 of the second color sensing unit 53. The light beams incident on incident regions A41 and A42 are guided by branch 44 to the third color sensing unit 54, and exit from the exit end 441 of branch 44 to the color filter 541 of the third color sensing unit 54. Figure 3 In this context, the symbols X, Y, and Z indicate which of the stimulus values X, Y, and Z the beam input from each incident region is used to measure.
[0064] Therefore, even if the beam incident on the incident surface A of the fiber bundle 4 has non-uniformity within the incident surface A, by adding the beams incident on the two incident regions at the point symmetrical position centered on the optical axis 40, the non-uniformity is averaged out, and the beams with reduced non-uniformity are emitted from each branch 41 to 44.
[0065] To explain this in more detail, when the incident surface A of the fiber bundle 22 is as follows... Figure 4 When the light is simply divided into four incident regions A1-A4, a non-uniformity in light intensity occurs among the four incident regions A1-A4 due to the light distribution characteristics of the object Q being measured. Therefore, when the rotational angular position of the incident surface A relative to the object Q being measured changes, the amount of light received by each light receiving sensor 512-542 of each color sensing unit 51-54 may change, resulting in a change in the tristimulus values obtained as measurement values.
[0066] That is, for example, such as Figure 5 As shown, consider a beam KSa that originates from a point in the measured region AR and enters the incident surface A, with a circular cross-section. Within this beam KSa, the upper half of the beam ( Figure 5 The portion of the beam (shown by slashes) is incident on the upper half of the incident surface A, and the lower half of the beam ( Figure 5 The portion of the object Q (without the slant line) is incident on the lower half of the incident surface A. This is not a problem when the light distribution characteristics of the object Q are symmetrical with respect to its normal, but it will become a problem when the light distribution characteristics are asymmetrical.
[0067] That is, such as Figure 6 As shown, when the upward-emitting beam KS from the object under test Q is larger than the downward-emitting beam, the upper half of the incident surface A becomes brighter and the lower half becomes darker. As a result, the amount of light incident on the four incident regions A1-A4 becomes non-uniform. Therefore, when the rotational angular relationship of the incident surface A relative to the object under test Q changes, the amount of light received by the same light-receiving sensor varies.
[0068] For example, in Figure 4 With the rotation angle shown, the upper incident area A1 receives the most light. However, when the fiber bundle 4 rotates and its rotation angle changes by 180 degrees, causing the incident area A1 to move downwards, its light reception becomes minimal. Thus, the arrangement between the measured object Q and the fiber bundle 4 alters the three stimulus values obtained as measurements, which can become measurement errors. In the case of liquid crystal panels, the asymmetry of light distribution characteristics is frequently observed, sometimes causing problems when measuring the optical characteristics of liquid crystal displays.
[0069] Therefore, as Figure 3As shown, multiple groups are formed, each consisting of two incident regions, which are located on opposite sides of the optical axis 40 of the incident surface A (e.g., incident regions A21 and A22). Each group is then associated with the exit ends 411-441 of each branch 41-44. Thus, even when the light distribution characteristics of the measured object Q are asymmetrical, the asymmetry is canceled out by adding the light received amounts from the two incident regions. Therefore, regardless of the rotation angle of the fiber bundle 4, beams of almost the same light quantity are emitted from the exit ends 411-441 of each branch 41-44. Therefore, the electrical signals output by each light receiving sensor 512-542 of each color sensing unit 51-54 are not affected by the asymmetry of the light distribution characteristics of the measured object Q, and thus the accuracy of the measurement values can be improved.
[0070] Next, the effect of setting up two second color sensing units 52 and 53 with spectral sensitivities corresponding to the Y component will be explained.
[0071] Consider the case where light beams emitted from the exit ends 411-441 of the branches 41-44 are received by light receiving sensors 512-542 via color filters 511-541, without a condenser lens. In this case, regarding the color sensing unit 52... Figure 7 As illustrated, the color filter 521 and light receiving sensor 522 are larger than the emitting end 421 of the branch 42. Therefore, problems arise in terms of installation space and cost. The color filter 521 and light receiving sensor 522 become more expensive as their size increases, so there is a desire to construct them with the smallest possible size. Furthermore, Figure 7 In the attached figure, reference numeral 522a is the unit surface of the light receiving sensor 522.
[0072] Next, as Figure 8 As shown, consider inserting a condenser lens 92 between the emitting end 421 of the branch 42 and the color filter 521 to reduce the size of the light receiving sensor 522. Let the area of the unit surface 522a of the light receiving sensor 522 at this time be S. Since the light beam emitted from the emitting end 421 of the branch 42 is focused by the condenser lens 92, it is different from the light without the condenser lens 92. Figure 7 Compared to the previous case, it can reduce the area S of unit surface 522a.
[0073] However, in order to improve the spectral sensitivity of the Y component, such as Figure 9 As shown, if the area S of the unit surface 522a is to be increased by a factor of two, the size of the output end 421 of the branch 42 of the fiber bundle 4 also needs to be increased by a factor of two. Furthermore, the effective diameter of the condenser lens 92 and the size of the color filter 521 also need to be increased by a factor of two. This would still result in a very high cost.
[0074] Therefore, by providing two second color sensing units 52 and 53, a structure can be achieved where sensors of the same size as the light receiving sensor 512 for the X component and the light receiving sensor 542 for the Z component can be used as the light receiving sensors 522 and 532 for the Y component. In other words, as the light receiving sensors 522 and 532 for the Y component, general-purpose light receiving sensors can be used, thus eliminating the need for large-sized special light receiving sensors or color filters, and improving the spectral sensitivity of the Y component while avoiding increased costs.
[0075] The above has described one embodiment of the present invention, but the present invention is not limited to the above embodiment. For example, although two second color sensing units 52 and 53 are provided for the Y stimulation value, there may be three or more.
[0076] This application claims priority to Japanese Patent Application 2023-219747, filed on December 26, 2023, the disclosure of which forms directly part of this application.
[0077] This invention can be used as a direct-reading colorimeter for stimulus values.
[0078] (Explanation of reference numerals in the attached image)
[0079] 1: Colorimeter (direct-reading colorimeter); 2: Objective lens; 3: Field stop; 4: Fiber optic bundle; 7: Computation unit; 8: Single semiconductor chip; 41-44: Branch section; 51: First color sensing unit; 52: Second color sensing unit; 53: Second color sensing unit; 54: Third color sensing unit; 61-64: Signal processing circuit; 92: Condensing lens; 100: Measured light beam; 101: Converged light beam; 411-441: Output end of branch section; 511-541: Color filter; 512-542: Light receiving sensor; 522a: Unit surface; 611-641: Integrator; 612-642: A / D converter; 613-643: Filter; A: Incident surface of fiber optic bundle; A11-A42, A1-A4: Incident area.
Claims
1. A direct-reading colorimeter for stimulus values, comprising: Multiple color sensing units are provided, each having multiple color filters and multiple light receiving sensors, wherein the multiple light receiving sensors receive light transmitted through each color filter; Multiple signal processing circuits, corresponding to each of the multiple color sensing units, are input with signals from each color sensing unit and have integration capabilities; as well as The arithmetic unit performs calculations on the outputs from the plurality of signal processing circuits. The plurality of color sensing units include: a first color sensing unit having a spectral sensitivity corresponding to the X component of the color matching function; a second color sensing unit having a spectral sensitivity corresponding to the Y component; and a third color sensing unit having a spectral sensitivity corresponding to the Z component. There are multiple second color sensing units. After each signal from the plurality of second color sensing units is processed in its respective signal processing circuit, it is added together in the arithmetic unit.
2. The direct-reading colorimeter based on stimulus values according to claim 1, wherein, The total area of the multiple light-receiving sensors constituting the multiple second color sensing units is greater than the area of each light-receiving sensor constituting the first color sensing unit and the third color sensing unit.
3. The direct-reading colorimeter based on stimulus values according to claim 1 or 2, wherein, A signal processing circuit includes an integrator, an A / D converter, and a filter, and the plurality of signal processing circuits are composed of a single semiconductor chip.
4. The direct-reading colorimeter based on stimulus values according to claim 1 or 2, wherein, The stimulus value direct-reading colorimeter also includes a light guide section, which guides the light from the object being measured to multiple color sensing sections respectively.
5. The direct-reading colorimeter based on stimulus values according to claim 4, wherein, The light guide is formed of optical fiber.
6. The direct-reading colorimeter based on stimulus values as described in claim 5, wherein, The light incident on the object being measured is directed to each color sensing unit by the incident region located at a point symmetrical about the optical axis in the incident surface of the optical fiber.
7. The stimulus value direct-reading colorimeter according to claim 5, wherein, The optical receiving sensor is composed of a Si photodiode.