JPH0642034B2 - Image exposure method for color negative film - Google Patents

Description

The present invention relates to an image exposure method for a color negative film,
In particular, the present invention relates to an image exposure method for a color negative film in which the same color negative film is used as an original image and a plurality of the same are exposed on a photosensitive material.

[Background of the Invention]

It has been well known that when a color negative film is exposed, the color negative film is discolored by the heat of a light source (fading is considered to be a plastic change), and such discoloration is common in the industry. It's a trivial matter. Conventionally, when performing multiple exposures (for example, printing a plurality of sheets) using the same color negative film,
During the second and second exposures, the heat from the light source has a long-term effect, so that it is necessary to read the image information of the color negative film every time in order to compensate for the change in the amount of transmitted light of the color negative film. A step of determining the exposure condition based on the read value is required every time, and it is common sense in the art to have such a step.

That is, in order to determine the exposure amount, it is necessary to measure the density of the color negative film that is the original image, but conventionally, for example, an optical sensor such as a photodiode provided near the optical path of the burning optical system is used. , Average transmission density over the entire area of a color negative film, that is, LATD (Large Ar
ea Transmittance Density) control is used for photometry. The image detection by this LATD control is to measure the average of the original image, and not to accurately measure the image density of the color negative film as the original image over the entire screen. Therefore, a method of dividing the image of the original image into left, right, upper, and lower sections and performing photometry, and determining the exposure amount based on the obtained two-dimensional image information (for example, Japanese Patent Publication No. 56-269).
No. 1) and the like are used together to determine a more appropriate exposure amount, but the density measurement of the color negative film for determining the exposure amount based on such two-dimensional image information is conventionally performed as described above. As described above, it is performed every time one sheet is printed.

This will be described with reference to the flowchart of FIG. First
As shown in the figure, when the process proceeds from S ₁ to S ₃ , printing is performed and the process returns to the start. Therefore, even when a plurality of exposures are continuously performed from the same color negative film, the density measurement for the number of printed sheets is repeated.

This means that the calculation for exposure amount determination is required every time, even though the same original image is printed.
This causes a problem that the printing speed is slow.
In particular, the determination of the exposure amount based on the two-dimensional image information described above
Since the amount of information is large as compared with the LATD control, the time required for one calculation is long and the printing processing time is further delayed.

That is, it takes a considerable time to obtain the two-dimensional information including the image processing, and thus this is the rate-determining condition when printing a plurality of sheets.

Further, when the two-dimensional information is obtained, the problem of noise is large, and the first measured value and the second read value may be greatly separated from each other due to noise.
The exposure conditions are extremely different between the first exposure and the second exposure, and even the same color negative film image may be printed completely differently. Thus, even with the same color negative film original image, the same two-dimensional image information cannot be obtained due to changes in density measurement conditions such as the influence of noise, voltage drop, or unexpected movement of the original image.
The problem is that the determination of the exposure amount becomes discontinuous and the finish is not uniform.

[Object of the Invention] The present invention was devised in view of the above problems, and a stable image exposure method capable of obtaining a uniform result at high speed and with little finishing unevenness even when a plurality of exposures are performed from the same color negative film. The purpose is to provide.

[Structure of Invention]

In order to achieve the above object, the present invention provides an image exposure method for a color negative film, wherein the same color negative film is used as an original image, and a plurality of the same is exposed on a photosensitive material. A step of reading image information on a color negative film image by photoelectric conversion to obtain two-dimensional image information; a step of determining an exposure condition based on the two-dimensional image information; and a color negative film image based on the exposure amount condition. The first exposure is performed by sequentially performing the exposure step of exposing the photosensitive material on the photosensitive material, and at least the second and subsequent exposures of the plurality of exposures are performed by the above-mentioned 2nd exposure read during the first exposure. The color negative film image is exposed on the photosensitive material based on the exposure condition using the three-dimensional image information.

The present invention reuses the two-dimensional information read in the first exposure at least in the second exposure.

With such a configuration, the image processing time of the two-dimensional information can be shortened and the processing speed for printing a plurality of sheets can be increased.

Further, the two-dimensional information is easily affected by noise, and different exposure control is performed between the first time and the second time due to the effect of noise, resulting in different finishes (e.g., different results even though the original image is the same color negative film). In some cases, the same finish (print) can be obtained even when a plurality of sheets are printed.

Further, although the color negative film generally fades due to the light from the light source, the two-dimensional information has less influence than the overall density change (LATD), and therefore, such processing is also possible.

The image information can be read by utilizing the reflected light or transmitted light of the color negative film which is the original image.

In the present invention, as the light-sensitive material, for example, resin coated paper, ballast paper, color photographic paper having white polyethylene terephthalate or the like as a support can be used.

In the present invention, the exposure amount and / or the exposure correction amount is determined based on the two-dimensional image information. There are cases where the exposure amount is determined only by the two-dimensional image information and cases where the conventional LATD control method is used in combination.

Two-dimensional image information can be read using an image sensor such as a CCD.

Embodiments Embodiments of the present invention will be described below with reference to the drawings. The following examples are merely illustrative of the present invention and the present invention is not limited to these examples.

The image information exposure method of the present embodiment is to irradiate the color negative film which is the original image with light, read the image information of the negative film, and project the image of the negative film on the photosensitive material.
A plurality of exposures, and in the first exposure of the plurality of exposures, a step of reading image information on the color negative film image by photoelectric conversion to obtain two-dimensional image information; The first exposure is performed by sequentially performing the step of determining the exposure condition based on the exposure amount condition and the exposure process of exposing the color negative film image onto the photosensitive material based on the exposure amount condition. In the second and subsequent exposures, the color negative film image is exposed on the photosensitive material based on the exposure condition using the two-dimensional image information read in the first exposure.

FIG. 1 shows a flow chart of the present embodiment. When the number of sheets is not printed, that is, when only one sheet is printed, the image is printed in S ₁ so that YES → S ₂ and the two-dimensional image information is displayed in S ₂ . When used for correction of the LATD control, the exposure correction amount is used, and when only the two-dimensional image information is used, the exposure amount is determined independently (in this specification, simply referred to as the exposure amount) → S ₃ , S ₃ The exposure is controlled with →
In S ₄ , since the number of sheets is not burnt, NO → printing (not shown) is performed and the process returns to the start.

Next, if the number key (for example, 2 sheets) is pressed in S ₄ ,
While first sheet is the same up to S _3, does not clear in NO → S _6, S ₆ so because the number baked at S ₄ baking YES → S ₅ set number is not completed in NO → not shown baking Is performed and the process returns to S ₂ . This is the second sheet of baking time, not the start, the flow returns to the place of the determined amount of exposure of S _2, it is possible to bake uses the same exposure as the first sheet continuously.

As for the operation method in the case of printing the number of sheets, if the number of sheets is input in advance by a ten-key etc. as shown in FIG. 1, the process returns from S ₆ to S ₂ and the same exposure is performed until the set number of sheets is printed (S ₅ ). It is possible to take a method of repeating baking by the amount.

Further, as shown in FIG. 2, it is possible to adopt a method in which the printing process is continued with the same exposure amount until the clear key is pressed.

For example, when printing two sheets (S ₁ ′), the exposure amount for the first sheet is determined (S ₂ ′) and the exposure is controlled (S ₃ ′). Since the number of sheets is baked in S ₄ ′, YE
Since S → S ₅ ′ and the process is repeated by always returning to S ₅ ′ → S ₂ ′ until it is cleared, printing can be performed with the same exposure amount. When the desired number of sheets have been printed (here, the second sheet), press the clear key to return to YES → start.

The exposure amount for printing the number of sheets can be temporarily stored in a readable / writable memory (for example, RAM), and the value can be repeated.

Various combinations can be used as the printing exposure amount input to the memory, and when the LATD and the two-dimensional image information are used together to determine the exposure amount, only the two-dimensional image information is stored in the memory and used. Can be measured every time, or the exposure dose determined by both the LATD and the two-dimensional image information can be stored and used. Further, when the exposure amount is determined using only the two-dimensional image information, this value is stored, but since the LATD information is not included at that time, B, G, R, and It is desirable to store in memory the results obtained for the three colors.

〔The invention's effect〕

As described above, according to the present invention, even when a plurality of exposures are performed from the same color negative film, it is possible to perform stable image exposure at high speed with less unevenness in the finish.

[Brief description of drawings]

FIG. 1 is a flow chart of a method for inputting the number of sheets with the ten keys to burn the number, and FIG. 2 is a flow chart of a method for continuously burning the number until the clear key is pressed.

Claims (1)

[Claims] 1. A same color negative film as an original image,
In a method of exposing a color negative film to a light-sensitive material in a plurality of times, in the first exposure of the plurality of exposures, image information on the color negative film image is read by photoelectric conversion to obtain two-dimensional image information. The first step is performed by sequentially performing a reading step, a step of determining an exposure condition based on the two-dimensional image information, and an exposure step of exposing the color negative film image onto a photosensitive material based on the exposure amount condition. Exposure is performed, and at least for the second and subsequent exposures of the plurality of exposures, the color negative film image is formed on the photosensitive material based on the exposure condition using the two-dimensional image information read at the first exposure. An image exposure method for a color negative film, which comprises exposing the film to light.