JPH0721619B2 - Color image exposure device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is a color image exposure for producing a color positive image from a color original image by using a copying color photosensitive material, particularly a silver salt copying color photosensitive material (hereinafter referred to as color paper). Regarding the device.

[Problems to be Solved by Prior Art and Invention] Light of a wavelength having a high sensitivity in each of the light-sensitive areas of blue, green and red light-sensitive layers of color paper is transmitted, and there is a certain level of lowness between the light-sensitive areas. An automatic color printer has been proposed in which a trimming filter for cutting light in the wavelength range is inserted (see Japanese Patent Laid-Open No. 53-64037).

This Japanese Patent Application Laid-Open No. 53-64037 discloses that by cutting both ends of the spectral sensitivity distribution of color paper, an improvement in color reproducibility can be obtained as a side effect. No consideration is given to the spectral characteristics of the dye, and the improvement in color reproduction cannot be obtained under the cutting conditions of the spectral light that does not cause a decrease in the sensitivity of the second sensitivity peak of blue sensitivity. That is, it is necessary to obtain the matching of the spectral sensitivity distributions and to improve the color reproducibility under the condition that the sensitivity is less deteriorated.
It is difficult to realize two effects at the same time.

FIG. 6 shows an average density distribution of each of the three primary color dyes of Y, M, and C when the mask density of the color negative film is removed. As shown in FIG. 6, the spectral distributions of the dyes overlap, and it is well known that the higher the density of the overlapping portions, the worse the color reproducibility of the color print.
For the above evaluation, the C, M and Y filter dyes are represented by the printing density (printing density) ratios (dye color mixing ratios) of R, G and B as shown in the following table (Table 1).

Here, the printing density (Dr, Dg, Db) of each color can be obtained by the following equation.

However, Jλ: Spectral luminance distribution of light source Siλ: Relative sensitivity distribution of i photosensitive layer of color paper Tiλ: Spectral transmittance distribution of i dye of color film i: One of red, green and blue j: Cyan, magenta , One of the yellows.

As can be seen from Table 1 above, for example, the burning density of the green photosensitive layer for yellow dye is 0.23, and the burning density of the blue photosensitive layer for magenta dye is 0.11, and in the case of magenta dye (R burning density 0.09 ) Or cyan dye (G
The value is considerably higher than the baking density 0.06). The main reason for this is due to the high sub-sensitivity region (M band absorption of G sensitizing dye) in the green light-sensitive layer at 490 to 520 nm. Moreover, in order to realize the conventional technique, it is necessary to use a dielectric multilayer film filter. In this case, unless the heat of the light source and the incident angle of light to the filter are properly adjusted, the required characteristics cannot be obtained. If it is not appropriate, it will have a negative effect.

Further, JP-A-53-64037 does not specify the proper location of the dielectric multilayer film filter, and it may be located anywhere between the light source and the color paper. . In this case, the wavelength shift due to the heat or the incident angle impairs the characteristics of the dielectric multilayer film filter.
The problems caused by the different locations of the dielectric multilayer film filters are listed below.

First, when the dielectric multilayer film filter is arranged between the light source and the light diffusing means, it is necessary to make the light from the light source a parallel light flux. Therefore, it is necessary to change the optical system and increase the size of various filters used as compared with the light source of the condensing type. When the above-mentioned optical system is not provided, the incident angle distribution of the light beam is wide, and the spectral transmittance characteristic of the color control filter is deteriorated, and the effect may not be obtained at all. Further, a change in spectral characteristics due to thermal influence may occur.

Next, when the dielectric multilayer film filter is arranged between the light diffusing means and the color photographic film, a large size color control filter is required depending on the size of the color photographic film. When parallel light is not used, the incident angle distribution of light on the dielectric multilayer film differs between the central portion and the peripheral portion, which causes color unevenness. Further, it is difficult to manufacture a filter having uniform characteristics in manufacturing (coating unevenness), and if it is intentionally manufactured, the cost is very high. further,
The change in the film size requires replacement of the dielectric multilayer film filter, which may be damaged or damaged during the replacement, which is not preferable.

Next, it is also shown that a dielectric multi-layer film filter is arranged between the photometric system and the negative film, but this cannot improve the color reproducibility of the color paper.

A method is known in which a dimming filter is inserted near the principal point of the lens unit to perform color control. However, this method also does not affect the spectral sensitivity distribution of color paper and does not improve color reproducibility.

In consideration of the above facts, the present invention slightly reduces the sensitivity of a copying color light-sensitive material containing color paper,
An object is to obtain a color image exposure device such as a color printer or a color copier that can improve color reproducibility.

[Means for Solving Problems] A color image exposure apparatus according to the present invention is arranged on an optical path by inserting a color light control filter into the optical path according to a photometric value of color light transmitted or reflected from a color original image. In a color image exposure device for obtaining a copied image by irradiating a copying color photosensitive material through a color light regulating means and a lens attached to a lens unit and controlling the exposure amount of each of the three primary color photosensitive layers of the copying color photosensitive material. It is characterized in that a dielectric multilayer coating filter, which constitutes a part of the color light regulating means and cuts a specific wavelength band in the visible region, is incorporated in the lens unit.

[Function] Copy color photosensitive material by incorporating a dielectric multilayer film having a short-wave absorption wavelength end and a long-wave absorption wavelength band, that is, a band-stop type dielectric multilayer film that cuts a specific wavelength band in the visible range into a lens unit. In particular, it is possible to greatly reduce the sub-sensitivity (sensitivity existing over a relatively wide wavelength range on the short-wave side of the maximum sensitivity shown by the shaded area in FIG. 2) of the silver salt copying color light-sensitive material, resulting in color reproduction. It is possible to improve the sex. Further, since the area of the dielectric multilayer film can be reduced, coating unevenness can be prevented.

Furthermore, there is no prior art in which the above bandstop type dielectric multilayer film is incorporated in the lens unit, and by arranging as in the present invention, the incident angle of light to the dielectric multilayer film becomes small with respect to the optical axis, It becomes close to parallel light. As a result, the wavelength shift due to the incident angle is reduced, and since it is away from the light source, there is no wavelength shift due to heat.

[Example] As shown in FIG. 1 (A), a lamp house 20 equipped with a light diffusion box 16 and a halogen lamp 18 is provided below the negative film 14 loaded in the negative carrier 10 and conveyed to the printing section. They are arranged in order. The upper part of the light diffusion box 16 is covered with a light diffusion plate (eg, milk glass) 17.

The dimming filter 22 is disposed between the lamp house 20 and the light diffusion box, and as is well known, a Y (yellow) filter,
3 for M (magenta) filter and C (cyan) filter
It consists of two filters.

A two-dimensional color image sensor 26 is arranged in a direction inclined with respect to the optical axis of the imaging optical system and at a position where the image density of the negative film 14 can be measured. In this embodiment, the photometer is a two-dimensional color image sensor.
Not limited to 26, for example LA of negative film
A photometer or a line sensor that measures TD may be used.

It is effective to use a filter (B filter, G filter, R filter) having the following characteristics for the two-dimensional color image sensor 26.

B filter: has a transmittance long-wave end in the absorption band of the BG control filter b or a wavelength range close to this (± 10 nm), or has a transmittance long-wave end approximate to the long-wave end of the copying light material B sensitivity distribution (± 10 nm). Have.

G filter: Transmittance in the absorption band of the BG control filter b or a wavelength range close to it (± 10 nm) and with a short wavelength end and transmission in the absorption band of the GR control filter c or a wavelength range close to it (± 10 nm) It has a transmittance long-wave end or a transmittance long-wave end approximated (± 10 nm) to the long-wave end of the sensitivity distribution G of the copying photosensitive material.

R filter: Has a transmittance short-wave end in the absorption band of the BG control filter c or in a wavelength range (± 10 nm) close to this.

Above the negative film 14, a lens unit 29, a black shutter 30 and a color paper 32 are arranged in order, and the light rays emitted from the lamp house 20 and transmitted through the light control filter 22, the light diffusion box 16 and the negative film 14 are. Multiple lenses 29A, 2 mounted in lens unit 29
9B, 29C, 29D, and 29E (see FIG. 1B) are configured to form an image on the color paper 32. In addition,
In this embodiment, a silver halide copying color light-sensitive material is applied as the color paper 32.

As shown in FIG. 1 (B), the lens unit 29 has the lenses 29A, 29B, 29C, 29D, and 29E fitted in predetermined positions in the axial direction of a cylindrical unit casing 40. Female screws 42 and 44 are formed at both ends of the inner peripheral surface of the unit casing 40, and can be easily attached to and detached from the apparatus main body by screwing with male threads of the main body (not shown).

A disk-shaped glass plate 46 is interposed between the lenses 29D and 29E. On both surfaces of this glass plate, a bandstop type dielectric multilayer film b having different characteristics, and
Alternatively, c is vapor-deposited to form the dielectric multilayer coat filter according to the present invention.

Further, as shown in FIG. 1 (C), a ring-shaped light-shielding film 48 is vapor-deposited on the vapor-deposited surface of the dielectric multilayer film c to serve as a fixed diaphragm plate for narrowing the light rays incident on the lens unit 40. I also have.

The dielectric multi-layer film b has a role of controlling light of B-sensitive long wave and G-sensitive short wave, and the dielectric multi-layer film c has a role of controlling light of G-sensitive long wave and R-sensitive short wave. Also, the lens unit
On the upstream side of 29, an ultraviolet cut filter a
Infrared cut filters d are arranged in the vicinity of 20, respectively, and constitute the color light regulating means 24 including the dielectric multilayer films b and or c. In this color light regulating means 24, B light is formed by the combination of the ultraviolet cut filter a and the BG regulating dielectric multilayer film b, and the BG regulating dielectric multilayer film b is formed.
G light is formed by the combination of the GR control dielectric multilayer film c and the GR control dielectric multilayer film c, and R light is formed by the combination of the infrared cut filter d and the GR control dielectric multilayer film c. Two types of band-stop type dielectric multilayer films do not necessarily have to be used at the same time. In that case, some of the effects of the present invention are reduced, but it is still more effective than the prior art, and the reduction of the effects may be supplemented by other means. Further, one of the dielectric multilayer film coat filters b and c may be arranged outside the lens unit. Further, the position of the ultraviolet cut filter a is not limited to this embodiment.

In this embodiment, as an example of the BG-regulated and GR-regulated dielectric multi-layer film, a layer composed of alternating layers of TiO2 and SiO2 and coated with several tens layers by vacuum vapor deposition is used.

Next, the BG regulated dielectric multilayer film b applied to this embodiment will be described with reference to FIG.

The transmittance of the absorption peak wavelength of the BG-regulated dielectric multilayer film b shown in FIG. 3 (A) is 30% or less, and its center wavelength is the wavelength at which the spectral absorption curves of the yellow dye and the magenta dye intersect (about
505 nm) (within ± 10 nm), and the half width is BG
The thickness of the regulated dielectric multilayer film b is 15 nm to 50 nm, and that of the GR regulated dielectric multilayer film c is 15 nm to 100 nm. FIG. 3 (B) shows the spectral sensitivity distribution of the color paper by cutting the light in the specific wavelength range by the BG control filter b (the solid line shows the spectral sensitivity distribution of the actual color paper). . It has the absorption long-wave end of the BG-regulated dielectric multilayer film in which the sensitivity wavelength of half of the maximum G sensitivity and the transmittance wavelength of half of the BG-regulated dielectric multilayer film substantially match (within ± 10 nm).

FIG. 3C shows the characteristics of the dimming filter used together with the BG-regulating dielectric multilayer film b. The cut wavelength edge of each dimming filter is included in the absorption wavelength band of the BG-regulating dielectric multilayer film b. As a result, even if each dimming filter is inserted into the optical path at the same time, the light in the wavelength band of the spectral transmittance change due to the overlapping of the spectral distributions is removed, so that the characteristics of the ideal dimming filter are not affected. Although it is difficult to prepare a magenta filter having a sharp cut wavelength that can be obtained, it is possible to eliminate the drawback with the BG-regulating dielectric multilayer film b.

As a result, it is possible to eliminate the problem of light absorption and leakage which are inconvenient in the light control filter spectral characteristics. Accurate exposure control could not be realized with the spectral characteristics of the conventional dimming filter based on the spectral sensitivity distribution of color paper. It should be noted that the present invention is also applied to a colored light cut filter instead of the light control filter, and the two are combined to form a colored light cut filter.

FIG. 4 shows in detail an example of curves of the short-wave absorption wavelength end and the long-wave absorption wavelength end that form the absorption band of the BG-regulated dielectric multilayer film b. As shown in FIG. 4, the falling start wavelength at the short wave absorption wavelength end is around 470 nm, the rising end wavelength at the long wave absorption wavelength end is around 530 nm, and the transmittance change ΔT is 1
There is a change of 40% or more per 0 nm.
There is no reduction in sensitivity between the peak sensitivity of and the peak sensitivity of green sensitivity, and both sensitivities can be reliably separated.

The operation of this embodiment will be described below.

The light emitted from the halogen lamp 18 is a negative film 14
The two-dimensional color image sensor 26 measures the transmitted light from the negative film 14 to obtain the exposure amount.

Next, on the optical path, a dimming filter 22 designed so that the cut wavelength end is included in the absorption wavelength band of the color light regulating means 24 is interposed, and the color paper 32 is accurately printed and exposed. By the way, the blue sensitivity of the color paper 32 has, in addition to the unique sensitivity peak, a second sensitivity peak in the long-wave side of this intrinsic sensitivity peak, that is, in the wavelength range close to the overlapping wavelength range with the green sensitivity. Therefore, the BG-regulated dielectric multilayer film b should not be cut, and at least the spectral absorption distribution of the yellow dye of the color filter and the green sensitivity distribution of the copying photosensitive material should be overlapped so as to greatly cut the green sensitivity in the wavelength range. The curves forming the short-wave absorption wavelength end and the long-wave absorption wavelength end are limited (see FIGS. 3 and 4). As a result, it is possible to improve the color reproducibility of the color paper with less deterioration in blue sensitivity. Table 2 shows the dye color mixing ratio when the BG-regulated dielectric multilayer film is used.

The Dg density of the yellow dye and the Db density of the magenta dye in Table 2 can be reduced, and more ideal color information can be transmitted from the color photograph to the color paper. This improves the color reproducibility of yellow and green. For this purpose, the Dg for the yellow pigment should be 0.15 or less. For this purpose, the sensitivity of the green photosensitive layer at 500 to 510 nm must be at least 1/2 or less. Further, it is desirable that the Dg for the yellow dye be 0.10 or less.

In this way, the BG-regulating filter b and the glass plate 46 on which the GR-regulating dielectric multilayer film c is vapor-deposited as shown in the present embodiment are arranged at the position where the conventional fixed diaphragm plate of the lens unit 29 is arranged. To suppress the decrease in transmittance at the B sensitivity long-wave end,
The color reproducibility is improved by greatly reducing the sensitivity of the G sensitivity spectral distribution of at least 500 to 510 nm. Also,
The light rays incident on the lens unit are close to parallel light, and the incident angle distribution and dependence of the light on the dielectric multilayer films b and c are very small. Further, the areas of the dielectric multilayer films b and c can be reduced, and uneven coating can be prevented. Further, as another method, the light-shielding film 48 is vapor-deposited on the surface of the GR-regulated dielectric multilayer film c, and the fixed diaphragm plate and the dielectric multilayer film coat filter are used together in one member, so that the number of parts is increased. There is no need to do this, and assembly is easy.
Since the fixed diaphragm plate is originally designed in consideration of conversion by the user, it is possible to easily attach this filter to the lens already used by the user.

In this embodiment, instead of the conventionally used fixed diaphragm plate, a dielectric multilayer film coater also having the function of this fixed diaphragm plate is applied. However, as shown in FIG. Alternatively, the dielectric multilayer coating filter 52 may be newly inserted at the principal point position of the lens unit 29 or in the vicinity thereof. Further, a dielectric multilayer coating filter may be attached to a conventional fixed diaphragm plate. That is, the dielectric multilayer coat filter can be inserted at any position in the lens unit in consideration of space, color unevenness, resolution area and the like.

The dielectric multilayer film filter 52 may be detachable or movable instead of being fixed. In this case, the C, M, and Y dimming filters can be used in combination. Further, the dielectric multilayer film filter 52 may be composed of two sheets and may be integrated or separated. Fixed aperture position when two filters are separated
50 and the main point or the vicinity thereof may be used.

By disposing a dielectric multi-layer film coated lens or a dielectric multi-layer film coated filter having the same characteristics as the above in the vicinity of the photometric lens disposed on the upstream side of the two-dimensional color image sensor 26 (see FIG. 5). It is possible to obtain coincidence of the spectral sensitivity distributions of the photometric system and the exposure system. Since the color separation filter symmetrical with respect to the central wavelength as shown in FIG. 5 can be easily formed by the organic filter or the dielectric multilayer film, this is used for the photometric system.

The above has described the case of printing from the color film to the color paper in the color image exposure apparatus.
It is also applicable to color paper to color paper, color film to color film, color paper to color film, and the like. It can also be applied to a color copying machine that copies a color original image (color photograph, color print, handwritten design image, etc.) to a reflective copying color photosensitive material such as color paper or a transmissive copying color photosensitive material such as OHP. It can be applied to the scanning exposure method as well as the surface exposure method. The above is the color light regulation filter with respect to the optical axis
Although the case where the mirror is arranged at an angle of 90 ° has been described, the present invention also includes the case where the mirror is arranged at an angle other than 90 °, for example, 45 ° and uses reflected light.

As described above, the color image exposure apparatus according to the present invention is
It has an excellent effect that the change in the sensitivity characteristic of the color paper is small, the color reproducibility is improved, and the inconvenient spectral distribution of the dimming filter can be corrected.

[Brief description of drawings]

FIG. 1 (A) is a schematic diagram showing a color image exposure apparatus according to this embodiment, FIG. 1 (B) is a sectional view showing the internal structure of the lens unit, and FIG. 1 (C) is a dielectric multilayer. FIG. 2 is a plan view of the film coat filter, FIG. 2 is a spectral sensitivity distribution characteristic diagram of color paper, and FIGS. 3 (A) to 3 (C) are relations with respect to respective wavelengths of the color control dielectric multilayer film, the color paper and the light control filter. Fig. 4 is a detailed diagram of the absorption band of the BG-regulated dielectric multilayer film, Fig. 5 is a transmittance characteristic diagram of a color separation filter that can be arranged near the photometric lens, and Fig. 6 is a color filter. Fig. 7 is an average relative spectral density distribution characteristic diagram of each dye of Y, M, and C when the mask density of Fig. 7 is removed. Fig. 7 is a sectional view when a new dielectric multilayer coating filter is added to the lens unit. is there. 14 …… Negative film, 18 …… Halogen lamp, 29 …… Lens unit, 32 …… Color paper (silver halide copying photosensitive material), 46 …… Glass plate, 48 …… Light-shielding film, 52 …… Dielectric multilayer Membrane coat filter.

Claims (3)

[Claims] 1. A color light control filter is inserted into an optical path according to a photometric value of color light transmitted or reflected from a color original image, and a color light control means and a lens mounted on a lens unit are arranged on the optical path. In a color image exposure apparatus for irradiating a copy color light-sensitive material and controlling the exposure amount of each of the three primary color light-sensitive layers of the copy color light-sensitive material to obtain a copy image, which constitutes a part of the color light regulating means and has a visible light range. A color image exposure apparatus characterized in that a dielectric multilayer coating filter for cutting a specific wavelength band is incorporated in a lens unit. 2. The dielectric multilayer coating filter is formed by depositing a dielectric multilayer on the surface of a transparent glass plate,
The color image exposure apparatus according to claim (1), characterized in that the peripheral edge portion of the glass plate is formed by light-shielding vapor deposition and is also used as a fixed diaphragm plate of the lens unit. 3. The color image exposure apparatus according to claim 1, wherein the dielectric multilayer film coating filter is arranged at or near the principal point position of the lens.