JPH01105932A - Photometry instrument for color photographic copying device - Google Patents

Abstract

PURPOSE:To make the red spectral sensitivity of an exposing system coincident with that of a photometry system and to eliminate the correction of exposure quantity by providing an absorption wavelength band formed between the short wave side wavelength end in the red spectral sensitivity distribution of a transfer photosensitive material and the long wave side wavelength end in the red spectral sensitivity distribution of a copying sensitive material. CONSTITUTION:A two-dimensional color image sensor 26 is arranged in the tilting direction with respect to the optical axis of an image forming optical system and in the position where the image density of a negative film can be subjected to photometry. The title instrument employs a B filter possessing a transmissivity long wave end in the absorption band of a BG regulation filter (a), a G filter possessing a transmissivity short wave end in the absorption band of the BG regulation filter (a) and also possessing a transmissivity long wave end in the absorption band of a GR regulation filter (b), and an R filter possessing a transmissivity short wave end in the absorption band of the GR regulation filter (b). Thus, by projecting light transmitting a color and light regulation filter 24, the spectral sensitivity of the photometry system can coincide with that of the exposing system.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a photometric device for a color photocopying machine that creates a color positive from a color photograph using a silver halide copying color photosensitive material (hereinafter referred to as "blade color paper"). Regarding.

[Prior Art] In exposure control of a color copying apparatus, it is important to match the spectral sensitivity distribution of the photometric system and the spectral sensitivity distribution of the exposure system. Conventionally, in photometering devices for color photocopiers, due to the mismatch in spectral sensitivity distribution between the two, it was necessary to set and store exposure conditions only for the type of color photo, and to manage these exposure conditions so that they were always appropriate. .

This effort is very large, and therefore exposure conditions are often not set properly, often resulting in the production of a large number of poor quality prints.

In order to match the spectral sensitivity distributions of the photometric system and the exposure system, conventionally, Cds is used as a charging converter, and in combination with a filter, it approximates the spectral sensitivity of color paper, and the printed density of the color paper and the density measured by the photometric system are compared. A color print color correction measurement device that reduces the difference between the light source and the photometer, transmits the light of the sensitive wavelength of each photosensitive area between the blue, green, and red photosensitive layers of the color paper in the optical path between the light source and the photometer, and An autocolor printer has been proposed in which a trimming filter is inserted to cut light in a wavelength range with low sensitivity between the photosensitive ranges (see Japanese Patent Application Laid-Open No. 53-64037).

Furthermore, as shown in Japanese Patent Application Laid-Open No. 51-113627, a color filter is inserted so that the copying light passing through the color film completely eliminates the light component corresponding to the overlapping wavelength region of two adjacent photosensitive regions of the copying paper. Copying methods have been proposed that either eliminate or greatly weaken this effect. This makes it possible to prevent the influence of spectral fluctuations of the exposure control filter, which is designed based on the maximum overlapping wavelength of two spectral sensitivity distributions of spectralally adjacent photosensitive layers of copy paper.

By the way, the spectral sensitivity range of photometric systems used in color printers is usually about 400 nm to 1200 nm, which is different from the spectral sensitivity range (380 nm to 760 nm) of silver salt copying color photosensitive materials that are often used as copy paper. ing.

Therefore, the spectral range of 760 nm to 1200 nm (infrared sensitive range) is unnecessary and needs to be cut. The maximum sensitivity of the photometric system is around 900 nm, and furthermore,
When an incandescent lamp such as a halogen lamp is used as a light source,
The light energy in the red to near-infrared wavelength region is much higher than that in the blue wavelength region. In order to cut out light in this wavelength range, an infrared cut filter coated with a dielectric multilayer film is usually used near the light source. - In the blade side optical system, a colored glass filter is used that cuts the infrared sensitive region. This colored glass filter cuts the sensitivity in the wavelength range (near infrared), which is highly sensitive and receives a high amount of light, to almost zero. In addition,
In order to cut light, an infrared cut filter made of the above dielectric multilayer film can be considered, but this dielectric multilayer film alone cannot cut light in a long wavelength band (800 nm - 1'200 nm) with very low transmittance. Therefore, colored glass filters are usually used.

As a colored glass filter, for example, a heat ray absorption filter such as product number HA-30 manufactured by Hoya Glass Co., Ltd. is often used. The characteristics of these colored glass filters are 1100
The transmittance in the wavelength band of 0n or more is almost 0%, and
Since it has a transmittance of about 50% at 700 nm, it is suitable as a filter to solve the above problems.

However, the drawback of heat-absorbing colored glass filters is that they do not have a sharp absorption wavelength edge, which is close to 600 nm (see arrow A in Figure 1).
The transmittance gradually decreases from the position indicated by ) toward longer wavelengths, and the transmittance does not decrease sufficiently even in the range of 800 nm to 900 nm (see graph I in FIG. 1). To solve this problem, the dielectric multilayer film described above is used in combination to prevent transmission of wavelengths from 760 nm to 1000 nm (see graph 1 in Figure 1).

With this photometric infrared cut filter (colored glass filter + dielectric multilayer film), the long wavelength end of the red spectral sensitivity is
The photometry system and exposure system will almost match.

[Problem that the invention seeks to solve]

However, in the above infrared cut filter, although the long wave side of the red spectral sensitivity distribution can be matched between the photometry system and the exposure system, no consideration is given to the short wave side of the red spectral sensitivity distribution. Therefore, as shown in FIG. 2, the spectral sensitivities of the photometric system and the exposure system do not match, resulting in a problem that an appropriate amount of exposure cannot be obtained.

Especially in the light source or near the light source, red light, green light,
In a type of copying device that produces blue light (for example, an additive color photocopying device or a color photoprinting device that has a color light regulation filter as in Japanese Patent Application No. 146544/1986), red light must be precisely aligned with the exposure system. Therefore, there is a problem that photometry cannot be performed.

This is because the exposure system side (that is, the red sensitivity of the color vapor) is shown in Figure 3 (refer to graph 3 in Figure 3), whereas the sensitivity increases rapidly from 600nm to 70Qnm, the photometry system side is photometry. 60 by infrared cut filter for
This is due to the fact that the sensitivity decreases from 0 nm to 700 nm (see graph 3 in Figure 3). Therefore, even if it receives the same red light as the exposure system, accurate photometric values of the color original image cannot be obtained.

The present invention takes the above-mentioned facts into account, and provides a photometric device for a color photocopying device that is capable of matching the red spectral sensitivity (exposure system) of a photosensitive material for copying and the red spectral sensitivity (photometric system) of a photometer, and particularly, to provide a photometric device for a color photocopying device. The object of the present invention is to obtain coincidence of the spectral sensitivity distributions in a type of photometer in which the spectral sensitivity distribution of the photometer is determined by the three primary color lights incident on the device.

[Means for Solving the Problems] The photometric device for a color photocopying apparatus according to the present invention has an infrared cutoff wavelength edge that is substantially coincident with the longwave side wavelength edge of the red spectral sensitivity distribution of the photosensitive material for copying. In a photometric device for a color photocopying apparatus that is equipped with a filter and measures primary color light transmitted or reflected from a color original image, the short wavelength end of the red spectral sensitivity distribution of the photosensitive material for copying and the long wavelength end of the green spectral sensitivity distribution of the photosensitive material are It is characterized by having an absorption wavelength band formed between the two.

[Operation] The infrared cut filter applied to the present invention has the following characteristics. In other words, the combination of the colored glass filter and the dielectric multilayer film makes the absorption wavelength end almost coincident with the long wavelength end of the red spectral sensitivity of the photosensitive material for copying, and the long wavelength end of the red spectral sensitivity distribution is used by the exposure system and the photometry system. It is matched with

Furthermore, in the present invention, at least a portion of the red transmittance is regulated by the dielectric multilayer film on the short wavelength side of the red spectral sensitivity distribution. That is, this dielectric multilayer film has a long-wavelength edge that approximately coincides with the short-wavelength edge of at least a portion of the red spectral sensitivity distribution in the photosensitive layer of the photosensitive material for copying, and a long-wavelength edge that is longer than the longwave-side wavelength edge of the green spectral sensitivity distribution. An absorption band is formed by the short-wave end, and the short-wave side of the red spectral sensitivity distribution of the photometer is regulated to substantially match the red spectral sensitivity distribution of the photosensitive material.

Note that the transmittance at the absorption peak of this absorption band is 1/2 or less of the maximum transmittance.

Therefore, by combining an infrared cut filter and a dielectric multilayer film, a filter with characteristics as shown in graph 1 in Figure 1, for example, can be obtained.
The large drop in transmittance to 00 nm is reduced, and the red spectral sensitivities of the photometric system and the exposure system are almost matched not only on the long side but also on the short wavelength side (see FIG. 6), making accurate photometry possible.

〔Example〕

As shown in FIG. 4, a light diffusion box 16 and a lamp house 20 equipped with a halogen lamp 18 are sequentially arranged below the negative film 14 loaded on the negative carrier 10 and conveyed to the printing section. Light diffusion box 16
The upper part of the light diffusing box 16 is covered with a light diffusing plate (for example, opalescent glass) 17, which constitutes a light diffusing means, and a colored light regulating filter 24 except for the infrared cut filter d is placed on top of the light diffusing plate 17. In addition, the light diffusion box 16
A dimming filter 22 is arranged between the halogen lamp 18 and the halogen lamp 18 .

As is well known, the light control filter 22 is composed of three filters: a Y (yellow) filter, an M (magenta) filter, and a C (cyan) filter.

The color light regulation filter 24 is a color light regulation filter coated with a dielectric multilayer film, and includes a BG regulation filter that passes B-sensitivity long waves and G-sensitivity short waves, and a GR regulation filter that passes G-sensitivity long waves and R-sensitivity short waves. b1 consists of an ultraviolet cut filter C and an infrared cut filter d.

In this colored light regulation filter 24, the color of the ultraviolet cut filter C and the BG regulation filter color are combined.
The combination of the BGG control filter 8 and the GR regulation filter forms G light, and the combination of the infrared cut filter d and the GR regulation filter forms R light.

In this example, T10 is used as an example of the dielectric multilayer film.
．． A material composed of alternating layers of and Sl ○2 and coated in several tens of layers by vacuum evaporation is used.

A two-dimensional color image sensor 26 is arranged in a direction oblique to the optical axis of the imaging optical system and at a position where the image density of the negative film 14 can be photometered. This two-dimensional color image sensor uses a filter having the following characteristics. That is, the transmittance has a long wave edge in the BG regulatory filter color absorption band or a wavelength range (±101 m) approximating it, or has a transmittance long wave edge that is close to the long wave edge of the photosensitive material B sensitivity distribution (±lQ nm). have B
The filter has a transmittance short wave end in the absorption band of BG regulation filter a or a wavelength range (±101 m) that approximates this, and has a transmittance in the absorption band of GR regulation filter b or a wavelength range (±101 m) that approximates this. It has a long wavelength edge or is close to the long wavelength edge of the photosensitive material G sensitivity distribution (±10 nm).
), the absorption band of the G filter with a transmittance at the long wavelength edge, or the absorption band of the GR regulation filter b, or a wavelength range close to this (±10 nm
), an R filter with a transmittance at the short wave end is used. By irradiating this with the transmitted light of the color light regulating filter 24, it is possible to match the spectral sensitivity distributions of the photometry system and the exposure system. Note that this embodiment is not limited to the two-dimensional color image sensor 26, and for example, a photometer that measures the LATD of a negative film may be used.

Above the negative film 14, a lens 28, a black shutter 30, and a color paper 32 are arranged in this order.
The light beams transmitted through the light diffusion box 16 and the negative film 14 are configured to be imaged onto the color paper 32 by a lens. Note that in this example, color paper 3
As No. 2, a silver halide copying color photosensitive material is used.

Here, the infrared cut filter d applied to this embodiment will be explained in detail.

As shown in FIGS. 1 and 3, graph (2), the infrared cut filter has one absorption peak between 600 nm and 700 nm. The short wavelength end of this absorption band is 550 nm
Further, the wavelength end on the long wavelength side substantially coincides with the wavelength end on the short wavelength side of at least a part of the infrared spectral sensitivity distribution of the color paper 32. The absorption peak of this absorption band exists between 6QQnm and 700nm, and its transmittance is less than 1/2 that of the area indicated by arrow A in FIG. In order to obtain such characteristics, the infrared cut filter d can have the following configuration.

(2) A dielectric multilayer film that cuts 780 nm to 11,000 nm is deposited on a colored glass filter, and a filter having characteristics as shown in FIG. 5 (hereinafter referred to as a notch filter) is combined. Note that the notch filter is a filter formed of a conductive multilayer film.

(2) A dielectric multilayer film as shown in FIG. 5 is deposited on a colored glass filter, and a multilayer coated filter that cuts 780 nm to 11000 nm is combined.

■ A notch filter with the characteristics shown in Figure 5 has a 780mm
A dielectric multilayer film that cuts wavelengths from nm to 11,000 nm is deposited, and a colored glass filter is combined.

Note that the wavelength range (780 nm to 101000 nm) changes depending on the applied color paper or colored glass filter, and is not limited.

By forming the infrared cut filter d in any of the above-mentioned modes (1) to (2), a filter having characteristics as shown in graph (2) in FIG. 1 is obtained.

Note that although the above-mentioned notch filter is integrated with the infrared cut filter, these may be provided separately.

The operation of this embodiment will be explained below.

The light beam irradiated from the halogen lamp 18 is irradiated onto the negative film 14 via the color light regulation filter 24, and the light transmitted from the negative film 14 is photometered by the two-dimensional color image sensor 26.

In the two-dimensional color image sensor 26, a red, green, and blue spectral sensitivity distribution is formed by the color light regulation filter 24,
The photometry is performed using the same effective sensitivity distribution as the effective sensitivity distribution of the color paper 32 (silver halide photosensitive material) used in this embodiment, and the exposure amount is obtained.

Next, on the optical path, there is a dimmer filter 2 designed so that the cut wavelength end is included in the absorption wavelength band of the color light regulation filter 24.
2 to accurately print and expose the color paper 32.

Here, the infrared cut filter d applied to this embodiment cuts the long wavelength side of the red spectral sensitivity distribution of the color paper 32, which is longer than the wavelength end, that is, wavelengths of 760 nm or more. This prevents the adverse effects on photometry caused by the high sensitivity of the sensor and the high amount of light, which are the characteristics of this wavelength range.

In addition, this infrared cut filter has a wavelength of 600 nm to 700 nm.
It has an absorption band between nm and prevents an adverse effect on the spectral transmittance characteristics of the heat ray absorption filter. This absorption band regulates at least a part of the short wavelength end of the red spectral sensitivity distribution, and makes the short wavelength end of the red spectral sensitivity distribution of the photometry system almost coincide with the short wavelength end of the red spectral sensitivity distribution of the exposure system. I'm letting you do it.

That is, when comparing the red spectral sensitivity distribution of the conventional infrared cut filter and the red spectral sensitivity distribution of this embodiment in their characteristic diagrams, the results are as shown in FIG. 2 (conventional) and FIG. 6 (this embodiment). . The characteristics shown by dotted lines in FIGS. 2 and 6 are the red spectral sensitivity distributions of the exposure system, and the characteristics shown by solid lines are the red spectral sensitivity distributions of the photometric system.

As can be seen from the graph in FIG. 6, in the evening, not only the wavelength ends on the long wave side are matched between the exposure system and the photometry system, but also the wavelength ends on the short wave side are almost matched. As a result, the photometric value obtained by the image sensor 26 is matched with the spectral sensitivity of the color paper 32 to which it is applied, and an appropriate exposure amount can be determined by calculation, eliminating the need for correction of the exposure amount after photometry. Become. Therefore, workability is improved and printing processing speed can be increased.

Although the above embodiments are related to a color photo printing apparatus using a color light regulating filter, the present invention can be similarly applied to an additive type color photo printing apparatus. Furthermore, although the above embodiments have been described with reference to the case of printing from color film to color paper, the present invention can also be applied to printing from color paper to color paper, from color film to color film, from color paper to color film, etc. Furthermore, the present invention can also be applied to a color copying apparatus using a silver halide photosensitive material that generally prints color original images (color photographs, color printing, etc.) onto color paper or color film.

The light source for copying is not limited to a halogen lamp, and can be similarly applied to a photometric system configured with a sensor having a sensitivity distribution in wavelengths longer than that of the copying sensitive material.

Generally, when a color filter with a large change in transmittance is used on the sensor side, it is effective to apply the present invention to prevent changes in the spectral sensitivity distribution using a notch filter. For example, a color temperature conversion filter may be used to reduce the long-wave sensitivity of the sensor. In this case, 450 nm and 5
It is preferable to adjust the spectral sensitivity distribution using a notch filter that has an absorption band within 50 nm.

[Effects of the Invention] As explained above, the photometry device for a color photocopying apparatus according to the present invention can substantially match the red spectral sensitivity (exposure system) of the photosensitive material for copying and the red spectral sensitivity (photometry system) of the photometer. This has the excellent effect of providing the optimum value for the applied silver halide color photosensitive material without correcting the exposure amount obtained by the photometric value.

[Brief explanation of the drawings] Figure 1 shows only a colored glass filter, a filter formed by depositing a dielectric multilayer film on a colored glass filter, and a filter formed by a combination of a colored glass filter, a dielectric multilayer film, and a 7-soti filter. Figure 2 is a red spectral sensitivity distribution characteristic diagram of the conventional exposure system and photometry system, Figure 3 is a spectral sensitivity distribution characteristic diagram of a conventional infrared cut filter, and Figure 4 is the present example. FIG. 5 is a characteristic diagram showing the transmittance of the notch filter applied to this embodiment, and FIG. 6 is a diagram showing the exposure system and photometry system of this embodiment. It is a red spectral sensitivity distribution characteristic diagram. 14... Negative film, 18... Halogen lamp, 24... Color light regulation filter, 26... Two-dimensional color image sensor, 32... Color paper (silver halide photosensitive material).

Claims (1)

[Claims] (1) For a color photocopying device that is equipped with an infrared cut filter with an absorption wavelength end that almost coincides with the longwave side wavelength end of the red spectral sensitivity distribution of the photosensitive material for copying, and that measures the primary color light transmitted or reflected from the color original image. A color photocopying device characterized in that the photometric device includes an absorption wavelength band formed between the short wavelength end of the red spectral sensitivity distribution and the long wavelength end of the green spectral sensitivity distribution of the photosensitive material for copying. photometric device.