JP5410244B2 - Instrument panel for vehicle and method for adjusting luminance and chromaticity of instrument panel for vehicle - Google Patents

Description

  An instrument panel for a vehicle and an instrument panel for a vehicle, comprising: a display unit that displays information about an instrument; a light source that illuminates the display unit from the back side; and a light control unit that dimmes light emitted from the light source. The present invention relates to a luminance / chromaticity adjustment method.

  For example, in a vehicle such as an automobile, an instrument panel on which a speedometer, a tachometer, and the like are mounted is provided at a position of an instrument panel in front of the driver's seat. In recent years, the instrument panel for vehicles has a structure that always illuminates the display part (a dial plate such as a scale plate) using illumination light not only at night but also in the daytime in consideration of visibility and design. There are many cases. In such an instrument panel for a vehicle, a light source is generally arranged on the back side of the dial, and each design area representing a scale or numerical value on the dial is made of a transparent or translucent material. The area of each design is illuminated using light emitted from the back side of the plate and transmitted through the dial.

  By the way, in such a vehicular instrument panel, it is necessary to illuminate a relatively wide area in the instrument. However, since illumination is generally performed using a point light source, if the distance between the dial and the light source is relatively close, the distance between each design area to be illuminated and the light source or the light path A difference arises every time, and the influence causes problems such as uneven illuminance.

  In order to prevent such illuminance unevenness, conventionally, dimming of illumination light is performed using a printing pattern arranged in a dot pattern. Such a technique is disclosed in, for example, Patent Document 1 and Patent Document 2.

  In patent document 1, in order to equalize the illumination intensity of the illumination light of the meter, a dot-like print pattern is formed using a mesh screen, and this pattern is printed on the transmitted light adjustment film of the meter. doing.

  Patent Document 2 discloses a technique for increasing the degree of freedom of lighting toning. Specifically, a dot-patterned fluorescent layer is provided at the location where the illumination light from the back of the instrument is dimmed, and the illumination light is synthesized by combining the emission color of each dot in the fluorescent layer with the light from the light source. Color adjustment is possible.

  Patent Document 3 discloses a technique for avoiding an increase in work man-hours associated with multicolor printing when making adjustments to eliminate unevenness in both illumination brightness and chromaticity of a meter. Specifically, a matrix sheet having a printing pattern formed by adjusting various mixing ratios of C (cyan), M (magenta), Y (yellow), and K (black) inks is used. A database that optically reads and represents the printing characteristics of the ink is created in advance. Using this database, it is possible to predict changes in luminance and chromaticity (X, Y, Z) before and after printing. Further, the luminance distribution of transmitted light is measured for each area to be printed in the illumination state of the instrument before printing, and the area is divided into about seven ranks according to the luminance. Then, for each brightness rank, print data (C, M, Y, K) necessary for eliminating unevenness in brightness and chromaticity is obtained from the contents of the database, and the light control film is printed using this print data. To form.

Japanese Patent Publication No.53-2065 Japanese Patent Laid-Open No. 2003-14502 JP 2006-78216 A

  If the prior art disclosed in Patent Document 3 is used, not only the luminance of illumination but also the chromaticity unevenness can be eliminated. However, since the chromaticity is not necessarily the same even in the region where the luminance of the illumination is the same, the chromaticity unevenness can be reduced only by adjusting the printing parameter for each region having a different luminance as in Patent Document 3. It is difficult to eliminate them completely.

  For example, in order to suppress uneven brightness of the illumination, a reflector is placed around the light source, and illumination is performed using a composite light that combines direct light from the light source and reflected light reflected by the reflector. The ratio of the direct light component and the reflected light component in the combined light changes according to the difference in the position of the region to be processed and the difference in the distance from the light source. In this case, a difference occurs in the spectrum (wavelength distribution) between the direct light and the reflected light according to the reflection characteristics of the reflecting plate, and thus the illumination light has color unevenness whose distribution state does not coincide with the change in luminance. Therefore, even if the print color is adjusted in accordance with the change in luminance, the color unevenness cannot be sufficiently eliminated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle instrument panel and a vehicle capable of precisely adjusting both luminance and chromaticity of illumination light according to design specifications. The object is to provide a method for adjusting the luminance and chromaticity of an instrument panel.

In order to achieve the above-described object, the vehicle instrument panel according to the present invention is characterized by the following (1).
(1) A vehicle instrument panel having a display unit for displaying information on a meter, a light source for illuminating the display unit from the back side, and a light control unit for dimming light emitted from the light source. ,
The light control unit has a dot-like print pattern,
The print color is adjusted independently for each halftone dot of the print pattern,
The printing color of each halftone dot cancels the color difference obtained as a difference between the detection value representing the luminance and chromaticity before printing obtained by measurement or calculation and the design target value regarding the luminance and chromaticity after printing. The correction value is determined in a direction opposite to the direction in which the detection value is viewed from the target value on the chromaticity space representing luminance and chromaticity, and the color difference from the target value. It was determined for each parameter of chromaticity according to the position of the adjustment point in the vicinity of the considerably shifted position.

  According to the vehicular instrument panel having the configuration of (1) above, the brightness and color of illumination light are obtained by performing printing using the correction value calculated so as to eliminate the color difference for each halftone dot of the print pattern. Since the degree is precisely adjusted, it is possible to prevent not only the brightness unevenness but also the color unevenness.

In order to achieve the above-described object, the luminance / chromaticity adjustment method for a vehicle instrument panel according to the present invention is characterized by the following (2) to (4).
(2) The display in the vehicle instrument panel, comprising: a display unit that displays information about the instrument; a light source that illuminates the display unit from its back side; and a light control unit that dimmes light emitted from the light source. A brightness chromaticity adjustment method for a vehicle instrument panel for adjusting the illumination brightness and illumination chromaticity of a part,
When forming a dot-like print pattern on the light control portion,
At least for each halftone dot of the printing pattern, a detection value representing luminance and chromaticity before printing is obtained by measurement or calculation,
At least for each halftone dot of the print pattern, the difference between the design target value related to the brightness and chromaticity after printing and the detected value is obtained as a color difference,
The correction value for canceling the color difference is located in a direction opposite to the direction in which the detection value is viewed from the target value on the chromaticity space representing luminance and chromaticity, and at a position deviated by the color difference from the target value. Decide for each chromaticity parameter according to the position of the adjustment point in the vicinity,
The distribution of each basic printing color is determined according to the correction value at least for each halftone dot of the printing pattern.
(3) The brightness / chromaticity adjustment method for a vehicle instrument panel according to (2) above,
The position of the adjustment point is changed according to at least one of the size of each halftone dot of the print pattern and the print film thickness.
(4) The brightness / chromaticity adjustment method for a vehicle instrument panel according to (2) above,
Using the (L * a * b *) color system, parameters (L *), (a *), and (b *) are acquired for each of the detected value, the target value, and the color difference, L *), (a *), and (b *) on the chromaticity space represented by the three parameters, or (a *) and (b *) on the chromaticity space represented by the two parameters. An adjustment point is determined, and three parameters (L *), (a *), and (b *) are determined for the correction value corresponding to the position of the adjustment point,
Converting the parameters (L *), (a *), and (b *) of the correction values into printing basic color parameters.

According to the method for adjusting the luminance and chromaticity of the vehicular instrument panel according to the above (2), the illumination light is printed by performing printing using the correction value calculated so as to eliminate the color difference for each halftone dot of the print pattern. The brightness and chromaticity of can be adjusted precisely.
According to the method for adjusting the luminance and chromaticity of the vehicular instrument panel in (3) above, the luminance and chromaticity of the illumination light can be adjusted more precisely. About the optical effect of the said light control part, it changes according to the magnitude | size of each halftone dot of the said printing pattern, or a printing film thickness. Accordingly, when the position that is located in the direction opposite to the direction in which the detected value is viewed from the target value and is shifted from the target value by the color difference is determined as the adjustment point in the chromaticity space, the size of each halftone dot is determined. In addition, an error may occur due to the influence of the difference in the printed film thickness, and color unevenness may occur. Therefore, the position of the adjustment point is determined in consideration of the influence of the size of each halftone dot and the difference in the printed film thickness.
According to the brightness chromaticity adjustment method for a vehicle instrument panel of (4) above, the correction values (L *), (a *), (b *) 3 parameters are determined, so that the color difference can be precisely adjusted to prevent color unevenness. That is, since the (L * a * b *) color system is excellent in color matching, a desirable result can be obtained as compared with the case of using an XYZ color system that does not have color matching.

  According to the vehicular instrument panel and the vehicular instrument panel luminance / chromaticity adjustment method of the present invention, both the luminance and chromaticity of illumination light can be precisely adjusted according to design specifications.

  The present invention has been briefly described above. Further, details of the present invention will be further clarified by reading through the modes for carrying out the invention described below with reference to the accompanying drawings.

It is a front view showing the appearance of the instrument panel for vehicles in an embodiment. It is sectional drawing showing the structure seen from the AA cross section of the vehicle instrument board shown in FIG. It is sectional drawing which expands and represents the cross section of the thickness direction in the vicinity of the design area of the part illuminated on the instrument panel for vehicles shown in FIG. It is a front view showing the specific example of the positional relationship of the design area | region shown in FIG. 3, and the halftone dot pattern printed. It is a flowchart showing the specific example of the process sequence in the case of printing a halftone dot pattern with the method of this invention. It is a chromaticity diagram showing the three-dimensional chromaticity space of the L * a * b * color system. It is a chromaticity diagram showing the a * b * coordinate plane of the L * a * b * color system. It is a schematic diagram showing the specific example of each parameter of the state of a design area | region, and the halftone dot pattern printed.

Specific embodiments relating to a vehicle instrument panel and a luminance / chromaticity adjustment method for a vehicle instrument panel according to the present invention will be described below with reference to the drawings.
The overall appearance of the vehicle instrument panel 10 in this embodiment is shown in FIG. As shown in FIG. 1, the vehicle instrument panel 10 has a speedometer 11 and a tachometer 12 mounted as a plurality of instruments in one device case 13.

  Each instrument includes a rotatable pointer 25 and a dial 21 supported by a central shaft 27. On the dial 21, visible information necessary for reading information indicated by the pointer 25 is formed as a design portion. The design portion includes a scale design portion 22, a numerical design portion 23, and a display unit design portion (km / h) 24.

  Since each of these design parts is made of a transparent or translucent material as will be described later, the illumination light emitted from behind the dial 21 (in the direction of arrow Z with respect to the dial 21) is emitted from each design part. Transparent. Therefore, the driver | operator who looks at this meter can see each design part in the state illuminated from the back side. Since the area excluding each design part on the dial 21 is colored by printing using an ink that does not transmit light, the area other than each design part is not illuminated from the back side.

  FIG. 2 shows the structure of the vehicular instrument panel 10 as viewed from a cross section taken along line AA in FIG. As shown in FIG. 2, the shaft 27 that supports the pointer 25 is connected to an internal unit 32 disposed behind the dial 21. The internal unit 32 has a built-in drive mechanism for moving the pointer 25. A light source 31 is fixed near the shaft 27, that is, near the center behind the dial 21.

  A curved light reflecting surface 13 a is formed behind the dial 21 as a part of the device case 13. The light reflecting surface 13a reflects the light emitted from the point light source 31 and guides the illumination light as shown by the respective optical paths 34 in the drawing, so that the efficiency of illumination is improved and each region to be illuminated is also provided. It helps to make the illuminance distribution uniform.

  In order to improve the visibility of each instrument, a turn-back 36 is formed on the upper part of the device case 13. A transparent front glass 37 is disposed on the front side of the dial 21 of each instrument (in the direction opposite to the arrow Z with respect to the dial 21). A wiring board 33 used for wiring to the internal unit 32 is disposed behind the light reflecting surface 13a. Further, the back of the inner unit 32 is covered with a back cover 35.

  FIG. 3 shows an enlarged cross-sectional structure in the thickness direction (arrow Z direction) in the vicinity of a portion 22a of the scale design portion 22 shown in FIG. The main body of the dial 21 is made of a transparent material (for example, a resin such as polycarbonate or acrylic), but is colored on the dial 21 by printing in order to selectively illuminate a portion requiring illumination from the back side. Is given. That is, as shown in FIG. 3, for the design portion 22a, a region (printing layer) that becomes visible information is formed on the surface side (surface opposite to the Z direction) by a coloring material that appropriately transmits light, In areas excluding each design part, an opaque part 21a formed by printing on the surface side a coloring material that does not transmit light is provided. That is, since the illumination light from the back of the dial 21 passes through only a certain area of each design part and reaches the surface side, the driver or the like sees only the design part from the back side. Can do. Therefore, good visibility can be obtained.

  On the back side (surface in the Z direction) of the dial plate 21, a light control printing unit 26 is provided at a location facing the design unit 22 a. The dimming printing unit 26 is for compensating for variations in luminance and chromaticity of the illumination light to obtain uniform illumination light that meets the design specifications, and appropriately attenuates the illumination light for each minute region. Thus, the luminance and chromaticity of each region are made uniform. More specifically, the light control printing unit 26 is formed as a halftone print pattern.

  A specific example of the positional relationship between the vicinity of a part of the design area 22a shown in FIG. 3 and the halftone dot pattern printed as the light control printing unit 26 is shown in FIG. As shown in FIG. 4, the light control printing unit 26 is configured as a set of a plurality of points (dots) regularly arranged at a constant pitch. Although the size of each point constituting the light control printing unit 26 is sufficiently smaller than the design region 22a, the size of each point is not constant. That is, by adjusting the size (area) of each point constituting the light control printing unit 26, the aperture ratio (area ratio, etc.) for each region is changed, and the attenuation amount of the illumination light transmitted through the dial 21 Can be adjusted.

  In the state shown in FIG. 4, since the case where the light source 31 exists in the right side of the design area | region 22a is assumed, the influence of the difference in the distance from the light source 31 arises. That is, in the design region 22a (upper side in FIG. 4) in a state before dimming by forming the light control printing unit 26, the illumination light amount increases as it approaches the right side, and the illumination light amount decreases as it approaches the left side.

  Therefore, as shown on the lower side of FIG. 4, a point having a relatively large area is disposed as the light control printing unit 26 on the right side of the design region 22 a, and a relatively area of the light control printing unit 26 is disposed on the left side of the design region 22 a. When a small point is arranged, the attenuation amount of the illumination light transmitted through the right side of the design area 22a is large, and the attenuation amount is small on the left side, so that the luminance distribution by the illumination light transmitted through the dial 21 is made uniform. In addition to changing the size of each point constituting the light control printing unit 26, it is also possible to adjust the film thickness to be printed or selectively use ink materials having different light transmittances.

  However, the distribution state of the luminance variation of the illumination light before dimming does not necessarily match the distribution state of the chromaticity variation. Therefore, the chromaticity variation cannot be corrected only by adjusting the attenuation amount of the illumination light transmitted through the normal halftone dot pattern as the light control printing unit 26.

  As can be seen from the state of each optical path 34 shown in FIG. 2, the illumination light that illuminates the dial 21 from the back is reflected by the component of the direct light that reaches the dial 21 as direct light and the light reflecting surface 13a. This is a combined light with the component of the reflected light that reaches the dial 21. If the light reflecting surface 13a has a certain color due to the characteristics of the material, a difference in chromaticity occurs between the direct light component and the reflected light component. In addition, since the mixing ratio of the direct light and the reflected light in the combined light is different for each area of the dial 21, the chromaticity of the illumination light varies from area to area due to this difference. This variation in chromaticity results in a distribution state different from the variation in luminance.

  For example, even if the direct light emitted from the light source 31 is white, if the light reflecting surface 13a has a slightly yellow color, the reflected light also becomes slightly yellow. In this case, in the example shown in FIG. 4, the chromaticity of the illumination light before dimming is close to the light of the light source 31 (direct light: white) on the right side of the design region 22a, but on the left side of the design region 22a. Since there are many components of the reflected light, the illumination light has a slightly yellow chromaticity as compared with the light from the light source 31. Accordingly, the chromaticity of illumination varies depending on the location on the design area 22a.

  A processing procedure of a method for eliminating such variations in luminance and chromaticity of illumination light is shown in FIG. The processing procedure of FIG. 5 will be described below.

  In step S11, the illumination light parameter P1 before dimming is obtained by measurement or computer simulation for each dimming position of the illumination spot on the dial 21. That is, the state of the illumination light that actually appears on the front side of the dial 21 based on the illumination light emitted when the light source 31 is turned on in the state before forming the light control printing unit 26 shown in FIGS. An illumination light parameter P1 representing brightness and chromaticity) is acquired for each light control position. When performing measurement, the luminance and chromaticity of each point on the dial 21 can be detected using a commercially available luminance meter, and numerical values representing the results can be obtained. When performing computer simulation, the spectral characteristics (spectrum) of the light emitted from the light source 31, the light transmittance for each wavelength of the dial 21, the light reflectance for each wavelength of the light reflecting surface 13a, the light The brightness and chromaticity of each point on the dial 21 can be estimated by calculating the attenuation amount of each part of each optical path 34 and wavelength based on information such as the shape of the reflecting surface 13a.

  In this embodiment, in order to represent the illumination light parameter P1 including luminance and chromaticity, a color system that is excellent in color matching (L * a * b *) is employed. Of course, other color systems may be adopted. In the (L * a * b *) color system, (L *) represents luminance and (a * b *) represents chromaticity. For example, by adjusting the size of each point of the light control printing unit 26, the luminance (L *) changes, but the chromaticity (a * b *) does not change. In order to eliminate the color difference ΔE that humans feel about the difference between the target color and the actual color, it is necessary to adjust both luminance (L *) and chromaticity (a * b *).

  In step S12 of FIG. 5, for each dimming position on the dial 21, the luminance of the illumination light target value P0 (luminance and chromaticity represented by L *, a *, b *) determined at the time of design is determined. The aperture ratio (the size of the dots and the printed film thickness) of each dot constituting the halftone dot pattern of the dimming printing unit 26 so as to eliminate the luminance variation according to the difference from the luminance of the illumination light parameter P1 before dimming. Etc.)

  In step S13, the color difference (ΔL *, Δa *, Δb *) is shifted to the opposite side when viewed from the position of the target value (P0) on the line connecting the positions of the parameters P1 and P0 in the chromaticity space. The point at the selected position is determined as the adjustment point P2.

  The chromaticity space of the (L * a * b *) color system is shown in FIGS. In FIG. 6, the three-dimensional chromaticity formed by three axes representing each of (L *), (a *), and (b *), which are each element of the (L * a * b *) color system. FIG. 7 shows a planar chromaticity space formed by two axes representing each of (a *) and (b *). In each chromaticity space shown in FIGS. 6 and 7, the center (origin) represents a point corresponding to the illumination light target value P0 (because the target color is white), and the position is shifted from the center. There is a point corresponding to the illumination light parameter P1. That is, a color difference exists between the illumination light target value P0 and the illumination light (P1) before dimming.

  The dimming amount necessary for canceling out this color difference corresponds to the adjustment point P2. That is, in each chromaticity space shown in FIGS. 6 and 7, the color difference (ΔL *, Δa *, Δb) is viewed from the position of the target value (P0) on the extension line of the line connecting the positions of the parameters P1, P0. *) A point at a position shifted to the opposite side of P1 by a considerable amount is defined as an adjustment point P2.

  If the position of the actual adjustment point P2 necessary for correctly correcting the color difference is within a certain allowable range, for example, within the range of the area AR shown in FIG. it can. Therefore, the adjustment point P2 does not necessarily have a positional relationship that is completely symmetrical with P1 with respect to the position of P0.

  Further, since the chromaticity after the actual light control is affected by the dot size and the film thickness, it is actually better to slightly shift the position of the adjustment point P2 from the position symmetric with P1. In some cases, the color difference of the color becomes small.

  Therefore, in step S14 of FIG. 5, the position of the adjustment point P2 determined in step S13 is shifted from the position of the symmetric point according to the aperture ratio (point size and film thickness) of the printing symmetric halftone dot. And optimize the position.

  A specific example will be described. The parameter of the target value (P0) is (L * = 10, a * = 0, b * = 0), and the parameter of (P1) before dimming is (L * = 12, a * = 1, b *) = 3), the color difference is (ΔL * = 2, Δa * = 1, Δb * = 3). In this case, the position of the adjustment point P2 determined in step S13 is (L * = − 2, a * = − 1, b * = − 3). However, the chromaticity after dimming is also affected by the size and film thickness of each halftone dot in the halftone dot pattern of the dimming printing unit 26, and can be optimized by taking this into consideration. That is, in step S14, the position of the adjustment point P2 is shifted from the symmetrical point, for example, the position (a * = − 0.5, b * = − 1.5) or (a * = − 2, b * = Correct to position -6).

  In step S15, parameters representing the position of the adjustment point P2 determined in step S14 (for example, L * = − 2, a * = − 0.5, b * = − 1.5) are obtained. That is, by printing each halftone dot pattern of the dimming printing unit 26 so as to match the parameter of the adjustment point P2, the position of the illumination light (P1) before dimming is adjusted to the target value (P0) after dimming. Can be close to the position.

  In step S16, the parameter (L *, a *, b *) of the adjustment point P2 is used as a basic printing color, that is, the color of each ink (for example, C, M, Y, etc.) used for printing by the light control printing unit 26. K) is converted to parameters such as density for each color, and print data of each color (C, M, Y, K) is created. The conversion from the parameter (L *, a *, b *) to (C, M, Y, K) can be processed by calculation using a predetermined constant and a predetermined mathematical formula, or can be performed in a predetermined manner. It is also possible to perform processing based on the contents of the lookup table.

  In step S17, the print data obtained in step S16 is acquired for each position of the halftone dot pattern of the print-symmetric light control printing unit 26, and printing is performed on the back surface of the dial 21 according to the print data.

  Parameters assigned when the halftone dot pattern is printed by the light control printing unit 26 are determined independently for each region, for example, as shown in FIG. In the example illustrated in FIG. 8, it is assumed that the chrominance of the target value (P0) is (a * = 0, b * = 0) when the light control printing unit 26 is to be printed at the design portion 22a. The distribution of the chromaticity parameter of the measurement value (P1) before dimming is shown in the upper side of FIG. 8, and the distribution of the chromaticity parameter (P2) used for printing by the dimming printing unit 26 is lower in FIG. Shown on the side.

  That is, as shown in the upper side of FIG. 8, in this example, the chromaticity parameter of the measurement value (P1) before dimming differs for each of the plurality of regions A1, A2, and A3 of the design portion 22a, and the color of the region A1 The degree parameter (P1) is (a * = 0, b * = 0), the chromaticity parameter (P1) of the area A2 is (a * = 1, b * = 3), and the chromaticity parameter (P1) of the area A3 is (A * = 2, b * = 6). Therefore, in order to compensate the color difference independently for each area, each halftone dot pattern is printed according to the chromaticity parameter (P2) that differs for each area as shown in the lower side of FIG. In the example of FIG. 8, the chromaticity parameter (P2) of the area A1 is (a * = 0, b * = 0), and the chromaticity parameter (P2) of the area A2 is (a * =-1, b * =-3). ), The chromaticity parameter (P2) of the area A3 is (a * = − 2, b * = − 6). By printing the light control printing unit 26 using such a chromaticity parameter (P2), the luminance and chromaticity of illumination can be brought close to the target values for all the regions of the design unit 22a.

  Note that when the light control printing unit 26 is printed, the chromaticity of the ink to be printed for each fine region can be adjusted by adopting, for example, an inkjet printer technique.

DESCRIPTION OF SYMBOLS 10 Vehicle instrument panel 11 Speedometer 12 Tachometer 13 Device case 13a Light reflecting surface 21 Dial 21a Non-transmitting part 22 Scale design part 23 Number design part 24 Display unit design part 25 Pointer 26 Light control printing part 31 Light source 32 Internal machine 33 Wiring board 34 Optical path 35 Back cover 36 Reflection 37 Front glass

Claims (4)

A vehicle instrument panel having a display unit for displaying information on a meter, a light source for illuminating the display unit from its back side, and a dimming unit for dimming light emitted from the light source,
The light control unit has a dot-like print pattern,
The print color is adjusted independently for each halftone dot of the print pattern,
The printing color of each halftone dot cancels the color difference obtained as a difference between the detection value representing the luminance and chromaticity before printing obtained by measurement or calculation and the design target value regarding the luminance and chromaticity after printing. The correction value is determined in a direction opposite to the direction in which the detection value is viewed from the target value on the chromaticity space representing luminance and chromaticity, and the color difference from the target value. A vehicle instrument panel determined for each chromaticity parameter in accordance with the position of an adjustment point in the vicinity of a considerably shifted position. Illumination of the display unit in a vehicular instrument panel, comprising: a display unit for displaying information relating to a meter; a light source for illuminating the display unit from the back side; and a dimming unit for dimming light emitted from the light source. A method for adjusting luminance and chromaticity of a vehicle instrument panel for adjusting luminance and illumination chromaticity,
When forming a dot-like print pattern on the light control portion,
At least for each halftone dot of the printing pattern, a detection value representing luminance and chromaticity before printing is obtained by measurement or calculation,
At least for each halftone dot of the print pattern, the difference between the design target value related to the brightness and chromaticity after printing and the detected value is obtained as a color difference,
The correction value for canceling the color difference is located in a direction opposite to the direction in which the detection value is viewed from the target value on the chromaticity space representing luminance and chromaticity, and at a position deviated by the color difference from the target value. Decide for each chromaticity parameter according to the position of the adjustment point in the vicinity,
At least for each halftone dot of the printing pattern, determine the distribution of each printing basic color according to the correction value;
Luminance chromaticity adjustment method for vehicle instrument panel. A method for adjusting luminance and chromaticity of a vehicle instrument panel according to claim 2,
A method for adjusting luminance and chromaticity of an instrument panel for a vehicle, wherein the position of the adjustment point is changed according to at least one of a size of each halftone dot and a printed film thickness of the print pattern. A method for adjusting luminance and chromaticity of a vehicle instrument panel according to claim 2,
Using the (L * a * b *) color system, parameters (L *), (a *), and (b *) are acquired for each of the detected value, the target value, and the color difference, L *), (a *), and (b *) on the chromaticity space represented by the three parameters, or (a *) and (b *) on the chromaticity space represented by the two parameters. An adjustment point is determined, and three parameters (L *), (a *), and (b *) are determined for the correction value corresponding to the position of the adjustment point,
A method for adjusting luminance and chromaticity of a vehicular instrument panel, wherein the parameters (L *), (a *), and (b *) of the correction value are converted into parameters of a printing basic color.

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