JPH0586618B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a standard white light source, and more specifically, to a standard white light source that can be stably maintained over a long period of time for use in maintaining and controlling reference white, which is the most important element for color reproduction, in factories producing color televisions and other products. The present invention relates to a white light source device. [Technical background and problems of the invention] The chromaticity point of the reference white color of color television is the range of a triangle on the chromaticity diagram determined by the chromaticity points of the three primary color (red, green, blue) phosphors used. It can be set arbitrarily. For example, the correlated color temperature of Japanese domestic products is approximately 9,000 to 12,000K, while some foreign products are approximately 6,500K. This variation in white chromaticity point causes the following problems in color reproduction of products. For example, if the color temperature of the product is set to 12,000K compared to the set color temperature of 10,000K, the entire image will have a bluish tinge, and at the same time, white Y-shirts will appear pale and strange. On the other hand, if the value is lowered to around 8000K, the image will look amber overall and white Y-shirts will look old. As described above, the chromaticity point of the reference white color of color television has a great influence on the final received image, and therefore strict color management is required. By the way, there are various methods for adjusting this reference white, but most of them are based on luminous matching with the standard white light source device, which is set to the chromaticity coordinates and brightness of the reference white according to the spectral side color, or by visual matching. A color checker or the like is used that stores the chromaticity values of the color television light-emitting surface that have been color-matched by color matching, and the basis of both is a standard white light source device. The general configuration of these standard white light sources is, for example, to obtain a light emitting surface with a correlated color temperature of 10,000K.
It consists of a daylight color fluorescent lamp with a color temperature of 6500K, a reflector, a color temperature conversion filter made of plastic or gelatin, a deviation conversion filter, a filter frame with a brightness adjustment dimming filter inserted, and a diffuser transmission plate, etc. It has the following problems. In other words, the spectral transmittance characteristics of plastic or gelatin filters used to adjust color temperature, deviation, and brightness change over time due to long-term use, and color temperature decreases and deviation increases during use. There has been a desire to improve the problem of chromaticity changes caused by chromaticity changes. [Object of the Invention] The present invention solves the above-mentioned problems and makes it possible to use white light, which is most important for color reproduction in color television, for a long period of time.
The purpose is to provide a standard white light source device that can be stably maintained. [Summary of the Invention] The present inventors have conducted studies on a standard white light source device that can obtain a desired chromaticity point without using plastic or gelatin filters conventionally used for chromaticity adjustment, and have found the following results. A standard white light source device of the present invention constructed as follows has been developed. That is, the standard white light source device of the present invention uses a fluorescent lamp made by coating the inner surface of a glass tube with a phosphor as a light source, a reflector plate for reflecting the light output from the light source to the front, and a luminance A fluorescent lamp incorporated in a device that emits light through an adjusting mesh filter and a diffuser-transmitting plate is characterized in that its reciprocal correlated color temperature is smaller than the reciprocal correlated color temperature of the light emitting surface, and more preferably 15 ~35 (MK ^-1 )
It is characterized in that it is small and its chromaticity coordinates on the CIE _uv chromaticity diagram are small by 0 to 0.01 (uv) in terms of distance from the perfect radiator locus. here,
The optimum color temperature and deviation range of the fluorescent lamp used in the apparatus of the present invention are determined as follows. For example, the spectral reflection and transmission characteristics of a reflector, diffuse transmission plate, etc. that are considered to be used in a standard white light source device are measured, and the chromaticity of the light emitting surface is predicted by simulation from the spectral energy distribution that approximates the light source used. Nowadays, simulation of the spectral energy distribution of a light source can be easily and accurately performed from the emission spectrum of the fluorescent material used, so by performing the aforementioned predictive calculations on various materials, the chromaticity point of the fluorescent lamp used can be determined using the spectral energy distribution. Even if the reflection and transmission characteristics are slightly different, predictions can be made with high accuracy. The above prediction calculations can be performed using currently commercially available reflectors (for example, aluminum satin reflectors), diffuse transmitting plates (for example, decorative glass, all milky white glass,
The optimal range of the fluorescent lamp as described above was found by examining combinations of light-reducing filters (eg, nylon mesh filters), etc. (opal glass, etc.). Here, the color temperature and deviation range were defined as follows.
In the case where the spectral reflectance and spectral transmittance characteristics of the reflector, mesh filter, and diffuser are respectively defined in claim 2, and the material has characteristics exceeding those ranges, of course The color temperature and deviation are outside the numerical ranges mentioned above. but,
From a chromatic perspective, materials with such characteristics are not preferred as reflective or transparent materials when adjusting white color as in this device. [Embodiments of the Invention] FIG. 1 shows a configuration diagram of an apparatus of the present invention. The light emitted from the fluorescent lamp 1, including the reflected light from the reflector 2, is radiated to the front via the filter frame 3 and the diffuser transmitting plate 4. Figure 2 shows the spectral reflectance of the reflector used in the present invention. Similarly, FIG. 3 shows the spectral transmission of the mesh filter, and FIG. 4 shows an example of the spectral transmission of the diffuse transmission plate. Furthermore, FIG. 5 shows a configuration diagram of a fluorescent lamp used in the apparatus of the present invention. Example 1 When obtaining a device with a color temperature of 6500K and a deviation of 0.003 uv on the light emitting surface using the reflector plate 5 in Fig. 2, 8 in Fig. 3, and 11 in Fig. 4, a mesh filter, and a diffuser plate. The fluorescent lamp used is Fluorescent A as shown in Table 1.
Table 2 shows the color temperature and deviation of the lamp manufactured using D and D. Furthermore, the spectral energy distribution of the fluorescent lamp and the light emitting surface are shown in FIGS. 6 and 7. Example 2 When obtaining a device with a color temperature of 9300K and a deviation of 0.005 uv on the light emitting surface using the reflector plate 6 in Fig. 2, 9 in Fig. 3, and 12 in Fig. 4, a mesh filter, and a diffuser plate. Fluorescent lamp B used is shown in Table 1.
Table 2 also lists the color temperature and deviation of lamps manufactured using D and D. Further, the spectral energy distribution of the fluorescent lamp and the light emitting surface is also shown in conjunction with FIGS. 6 and 7. Example 3 When using the reflector, mesh filter, and diffuser plate 7 in FIG. 2, 10 in FIG. 3, and 13 in FIG. Table 2 also shows the color temperature and deviation of the fluorescent lamps manufactured using the phosphors C and D shown in Table 1. Further, the spectral energy distribution of the fluorescent lamp and the light emitting surface is also shown in conjunction with FIGS. 6 and 7. Comparative Example When obtaining the luminous surface chromaticity as in Example 3,
Using a commercially available daylight fluorescent lamp (the phosphor used is Fluorescent E shown in Table 1), the reflector plate 7 in Figure 2 and 10 in Figure 3, the diffuser plate and the filter frame were coated with the 8
The plastic neutral density filter shown in 14 in the figure (for example, ND-50 made by Soudensha), the plastic color temperature conversion filters 15 and 16 in Fig. 8 (for example, TB ₁ and TB ₃ made by Tokyo Stage Lighting), and No. 17 and 18 plastic deviation conversion filters (for example, PU ₁ and PU ₄ manufactured by Soudensha) are inserted and manufactured. The results are shown in Table 2 and Figures 6 and 7. Note that each symbol in the figure corresponds to the light emitting surface chromaticity and lamp symbol in Table 2. As is clear from the above embodiments, in contrast to the conventional method using a plastic filter, the apparatus of the present invention can achieve a predetermined luminous surface chromaticity by simply manufacturing a fluorescent lamp of each chromaticity as shown in the embodiments. It can be seen that the following can be obtained. In addition, since it can be obtained without using plastic filters that inevitably suffer from photobleaching, as shown in Table 2, there is very little change over time, and the chromaticity shift has been improved to the extent that it does not become a problem even after 1000 hours of lighting. . Incidentally, the phosphor used in the fluorescent lamp used in the device of the present invention may be a type of phosphor other than the examples or a mixture of a plurality of phosphors with different composition formulas, and in short, a phosphor within the above-mentioned chromaticity range. If there is, the phosphor used is the first one.
It is not limited to the table in any way. [Effects of the Invention] As is clear from the above description, the device of the present invention uses a fluorescent lamp set to a predetermined chromaticity, thereby eliminating the need for a plastic filter that causes chromaticity deviation. However, the desired chromaticity of the light emitting surface can be obtained. Also, in the past, the transmittance of plastic filters was set in steps, so the color temperature...
Although it was not possible to adjust the deviation stepwise, the device of the present invention has the advantage that the chromaticity of the fluorescent lamp can be set arbitrarily, so that the chromaticity can also be set linearly.

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【table】 [Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining the device of the present invention,
Fig. 2 is a characteristic diagram showing the spectral reflectance of the reflector used in the device of the present invention, Fig. 3 is a characteristic diagram showing the spectral transmittance of the mesh filter of the present invention, and Fig. 4 is a characteristic diagram showing the spectral transmittance of the mesh filter of the present invention. A characteristic diagram showing the spectral transmittance, FIG. 5 is a schematic diagram of the fluorescent lamp, FIGS. 6 and 7 are diagrams showing the spectral energy distribution of the fluorescent lamp and the light emitting surface in the example, respectively, and FIG. 8 9 is a diagram showing the spectral transmittance of a plastic filter in a conventional example, and FIG. 9 is a chromaticity diagram showing the light color of a fluorescent lamp and a light emitting surface in an embodiment. 19... Glass tube, 20... Fluorescent material, 21...
Base, 22...Base pin, 23...Electrode, 1...
Fluorescent lamp, 2...reflection plate, 3...filter frame, 4...diffuse transmission plate.

Claims (1)

[Scope of Claims] 1. The light source is a fluorescent lamp formed by coating the inner surface of a glass tube with a phosphor, and a reflector plate for reflecting the light output from the light source to the front, and the light output has a brightness. A standard white light source configured to emit light through an adjusting mesh filter and a diffuser transmission plate, wherein the fluorescent lamp has a reciprocal correlated color temperature smaller than that of the light emitting surface. Device. 2 The fluorescent lamp has a reciprocal correlated color temperature that is 15 to 35 (MK ^-1 ) lower than the reciprocal correlated color temperature of the light emitting surface, and the chromaticity coordinates on the CIE _UV chromaticity diagram are different from the perfect radiator locus. The standard white light source device according to claim 1, characterized in that the distance is 0 to 0.01 (uv) smaller.