JPH05346627A - Exposure determination device for copying device - Google Patents

Abstract

PURPOSE:To obtain the exposure determination device of a copying device which can determine an optimum exposure with a little photometric data and can be reduced in the size of the device. CONSTITUTION:The image recorded on a negative film is divided into many pieces by three pieces of area sensors and is metered by sepn. to 9 colors (step 124). The spectral distribution of the image is estimated in accordance with the previously determined plural main component spectral distribution (steps 128, 130) and the image density (basic exposure) equiv. to the image density determined by metering the image with the sensors of the spectral sensitivity distribution equal to the spectral sensitivity distribution of color paper is determined (steps 132, 134). On the other hand, a correction quantity is computed in accordance with the image data of three colors in the photometric data on 9 colors obtd. by the photometry (step 136). The error of the correction rate by the difference in the spectral sensitivity distribution between the sensors and the color paper is corrected (step 138). The exposure is determined in accordance with the image density and the corrected correction quantity (steps 140, 142).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure amount determining device for a copying machine, and more particularly to an exposure amount determining device for a copying machine used in a copying machine for copying an image recorded on a film onto a copying material such as photographic paper. Regarding

[0002]

2. Description of the Related Art Generally, the exposure amount when a color image is copied from a color original image to a copying material such as a photosensitive material is provided with a color separation filter composed of a dye filter or a vapor deposition filter. The integrated transmission densities of red (R), green (G), and blue (B) light are measured using the photometric device described above and determined for each of R, G, and B light. In order to accurately determine the exposure amount, it is necessary to exactly match the spectral sensitivity distribution of the photometric device and the spectral sensitivity distribution of the copying material.
The spectral sensitivity distribution of this copying material has a complicated distribution that is asymmetric with respect to the wavelength at which the photosensitivity is maximized. Therefore, it is necessary to combine a large number of filters in order to create it with a dye filter or a vapor deposition filter, which makes it difficult to mass-produce and has a problem of low accuracy.

Therefore, in the photoresist exposure apparatus, the light from the original image is decomposed into spectral light, and the decomposed light is weighted and added to perform a process of adding the spectral sensitivity distribution of the photometric device to the spectral sensitivity distribution of the copying material. Is known to match. Japanese Unexamined Patent Publication No. 58-88624 discloses that the photoresist exposure apparatus uses a diffraction grating, a converging optical system, and a photodetector to perform the above-described processing. A complex mechanism is needed to ensure that it does not change. Japanese Patent Laid-Open No. 61-95525 discloses a photoresist exposure apparatus in which a large number of interference filters are arranged in place of the diffraction grating. However, since the same number of interference filters as the number of decomposed lights is required, it is difficult to mass-produce when the number of photometric wavelengths is large.

Further, in the color photographic printer,
In Japanese Patent Laid-Open No. 1-134353, a prism, a diffraction grating, or a spectral filter is used to spectrally decompose the light transmitted through the image recorded on the film, and a part of the copy document is connected to the photoelectric sensor panel in a slit shape. Imaging is disclosed. In the above, light at different photometric positions is incident along the rows of the photoelectric sensor panel, and the spectral light at each photometric position incident along the columns of the panel is converted into an electric signal to gradually move the film. By moving the slit light transmitting portion on the original image, the entire screen is measured. Each spectrum of each photometered pixel is multiplied by a weighting factor corresponding to the spectral sensitivity distribution of the copying material to obtain a photometric value equal to that measured by a sensor having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material.

However, when a diffraction grating or a spectral filter is used, the same problems as described above are encountered. When a prism is used, color separation is caused by refraction, and therefore it is necessary to make the projection light parallel. Becomes larger,
Due to the spectral sensitivity distribution of the photoelectric sensor, it is difficult to measure the spectrum with the same amount of light on the same panel. In addition, because the rows are decomposed into columns, there is a drawback that the light intensity is significantly reduced, especially when the image density is high.It is necessary to reduce the spectral resolution to perform photometry and interpolate (interpolate) between the measured spectra. I have to.

Further, in Japanese Patent Laid-Open No. 1-142719, slit light projected on an image recorded on a film is used as a prism,
Decompose into a number of spectra with a diffraction grating, etc., and use a two-dimensional array sensor to perform photometry to obtain the average concentration.
And a second photometric unit for obtaining an exposure amount by obtaining an average density by scanning photometry, and an average density obtained by the first photometric unit and an average density obtained by the second photometric unit. The exposure amount is corrected based on the comparison result. However, since the prism and the diffraction grating are used, there is a problem similar to the above. Further, since it is necessary to provide two photometric units, there are drawbacks that the device is further increased in size and restrictions on component arrangement are increased.

In connection with this, the applicant has a first sensor for resolving and measuring a film image into a number of spectra and a maximum sensitivity in a wavelength band corresponding to three sensitivity wavelength bands of a copying material. A second sensor for dividing the image into a large number of pieces for photometry, multiplying the photometric value of the first sensor by a weighting factor corresponding to the spectral sensitivity distribution of the copying material to obtain an average density, There is proposed an exposure amount control device (see Japanese Patent Laid-Open No. 3-230148) in which a correction amount is obtained by a sensor and the exposure amount is determined by both.

In the above exposure amount control apparatus, the interference filter is configured to change the thickness of the interference film continuously or stepwise so that the wavelength of the color to be decomposed changes depending on the light irradiation portion, and a two-dimensional image sensor. Since the first sensor is configured by, the diffused light can be used for photometry, but since it is necessary to provide two photometric units, it is difficult to miniaturize the device. Further, unless the light that has passed through the film image and is incident on the first sensor is completely diffused and made uniform, a spectral error occurs and an appropriate exposure amount cannot be obtained.

On the other hand, the energy distribution of the light source used for photometry, the spectral sensitivity distribution of the photometric device, etc. are obtained in advance, and the photometric device having the spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material is calculated by a microcomputer. The following method of determining the post-exposure amount after obtaining a photometric value equivalent to that at the time is also considered.

That is, the spectral energy distribution of the light source used for photometry is P (λ), and the spectral sensitivity distribution of the photometric device is S.
(Λ), where ρ (λ) is the spectral transmittance distribution of the developed silver or color dye on the film, the density D measured by the photometric device in the wavelength range s to l is expressed by the following equation (1).

[0011]

[Equation 1]

Therefore, the spectral sensitivity distribution S of the copy material is
_The density D measured with a measuring device having a spectral sensitivity distribution equal to _p (λ) can be obtained by replacing S (λ) in the above formula (1) with the spectral sensitivity distribution S _p (λ) of the copying material. ..

Since the spectral energy distribution P (λ) of the light source and the spectral sensitivity distribution S _p (λ) of the copying material are obtained by measuring in advance, the spectral transmittance distribution ρ (λ) of the film which differs depending on the film is estimated. Then, the density measured by the photometric device having the spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material can be obtained from the equation (1). Then, the exposure amount can be determined based on this density. According to this method, since it is not necessary to use a diffraction grating or a large number of interference filters as in the above-mentioned conventional technique, the photometric device can be manufactured in a small size and at low cost.

However, in the method using the above microcomputer, a method for accurately estimating the spectral transmittance distribution of the film has not been established, and photometry is performed with a photometric device having a spectral sensitivity distribution equal to that of the copying material. There is a problem that the photometric value cannot be calculated accurately by calculation.

The present invention has been made in consideration of the above facts, and an optimal exposure amount can be determined with a small amount of photometric data, and an exposure amount determining device for a copying machine can be obtained which can be downsized. That is the purpose.

[0016]

In order to achieve the above-mentioned object, an exposure amount determining apparatus of a copying apparatus according to the present invention divides an image recorded on a recording material into a large number of images, and divides the image into a predetermined number of four or more colors. A photometric unit that decomposes light into a number of colors for photometry, a storage unit that stores photometric data of a number of colors obtained by photometry of the photometric unit, and the image using the photometric data of a number of colors stored in the storage unit. Estimating means for estimating the spectral distribution of each pixel obtained by dividing the image into a large number or the entire screen of the image or a part of the screen, and the spectral sensitivity of the copying material using the estimated spectral distribution and the spectral sensitivity distribution of the copying material. Image density calculating means for obtaining an image density equivalent to the image density obtained by photometrically measuring the image with a photometric means having a spectral sensitivity distribution equal to the distribution, and photometry for at least three colors of the stored multicolor photometric data. Correction amount determining means for determining the correction amounts of the three colors with respect to the image density based on the data, and the exposure amount for correcting the image density with the correction amount determined by the correction amount determining means to determine the copy exposure amount. And a determining means.

The estimating means obtains a weighting factor to be given to each of the plurality of principal component spectral distributions based on the photometric data of a large number of colors and the plurality of principal component spectral distributions obtained in advance, and uses the weighting factor. It is preferable to estimate the spectral distribution of the image by obtaining a linear sum of the plurality of principal component spectral distributions.

Further, it is preferable that the photometric means performs photometry with light emitted from a light source for copying and transmitted or reflected the image.

Further, the photometric means can be composed of two or more area sensors which divide the image into a large number and divide it into two or more colors for photometry.

When the photometric means is composed of two or more area sensors, at least one of the area sensors has a maximum sensitivity in the wavelength band corresponding to the sensitivity wavelength bands of the R, G, and B colors of the copy material. However, photometry in the corresponding wavelength band can be performed.

Further, the photometric means can be composed of four or more line sensors for photometrically dividing an image into a large number.

Further, a plurality of line sensors may be used as the photometric means, the image may be divided into a large number, and the image may be decomposed into a large number of four or more colors for photometry.

[0023]

According to the present invention, the image recorded on the recording material by the photometric means is divided into a large number of pieces, and the image is decomposed into a large number of predetermined four or more colors for photometry, and the photometric data obtained by the photometry is used. The spectral distribution of each pixel obtained by dividing an image into a large number of pixels or the entire screen of the image or a part of the screen is estimated. Less than,
As an example of the method of estimating the spectral distribution, a method of estimating the spectral transmittance distribution of an image recorded on a negative film as a recording material by using the main component spectral transmittance distribution will be described.

The spectral transmittance distribution ρ (λ) of the image is
The Nth N principal component spectral transmittance distributions e ₁ (λ), e
₂ (lambda), assuming that without using all of the _{e 3 (λ) ··· e N} (λ), can be estimated by a linear sum of k main component spectral transmittance distribution of the first to k of which Then, this spectral transmittance distribution ρ (λ) can be expressed by the equation (2).

[0025]

[Equation 2]

The N main component spectral transmittance distributions e
₁ (λ), e ₂ (λ), e ₃ (λ) ... e _N (λ) are multi-colors (eg 72 colors) for one or more (eg 10) color negative films. It is possible to obtain the color sample image by preparing M color sample images and analyzing the measurement result of the spectrometer. That is, each sample image is
For example, the spectral transmittance measured for each wavelength at intervals of 5 nm to 10 nm from 400 nm to 760 nm can be expressed as ρ ₁ to ρ _{M as} shown in equation (3).
And In the case of 10 nm intervals, N = 36. Note that ρ ₁₁ , ρ ₁₂ , ..., ρ _N1 etc. in the equation (3) indicate the spectral transmittances measured at 10 nm intervals, for example.

[0027]

[Equation 3]

Principal axis vector e is obtained by principal component analysis of equation (3).
i (however, i = 1, 2, ... N) is calculated. In this method, first, the correlation matrix Σ of equation (4) is calculated, and the eigenvalue and eigenvector of Σ are calculated.

[0029]

[Equation 4]

Since the matrix Σ is a symmetric matrix, the eigenvalue is 0 or more, and the largest eigenvalue is U ₁ ² , U ₂ ² , U ₃ ² ,
... U _N ^2, and the eigenvectors corresponding thereto are normalized to e ₁ , e ₂ , e ₃ , ... e _N.

Let the matrix e be e = [e ₁ , e ₂ , e ₃ , ...
e _N ],

[0032]

[Equation 5]

And becomes symmetric. If the vector ei is expressed as ei (λ), the spectral transmittance distribution ρ (λ) of the color sample is

[0034]

[Equation 6]

It can be expressed as The sum of the terms up to the kth term in equation (6) corresponds to equation (2). Therefore, the spectral transmittance distribution ρ (λ) of the film can be estimated by determining the weighting factors a ₁ , a ₂ , ..., A _k in the equation (2). Further, since the density is the logarithm of the transmittance, the spectral transmission density distribution can be obtained.

Next, a method for determining the weighting coefficients a ₁ , a ₂ , ... A _k will be described. The spectral energy distribution of the light source is P (λ), the spectral sensitivity distribution of the k sensors is S ₁ (λ),
As S ₂ (λ), ... S _k (λ), the spectral transmittance distribution ρ (λ) of the image recorded on the film is the main component spectral transmittance distributions e ₁ (λ), e ₂ (λ), When expressed by the linear sum of e _k (λ), each sensor output, that is, the photometric value is as follows.

[0037]

[Equation 7]

Here, the photometric value Be q ₁ , q ₂ ... q _k , _Are represented by a matrix as e ₁₁ , e ₂₁ , ... E _kk , respectively,

[0039]

[Equation 8]

[0040]

[Equation 9]

Then, the photometric value and a plurality of main component spectral transmissions
Weighting coefficient a based on the rate distribution₁, A ₂... a_kIs
To be And by substituting this value into equation (2),
The spectral transmittance distribution ρ (λ) of the film is estimated
become. Also, from this spectral transmittance distribution,
It is possible to estimate the cloth and the spectral transmittance distribution.

In the above, a sensor having a sensitivity distribution of a predetermined width is used.
It is assumed that the meter will be used for metering, but
If the cloth is a narrow band, each wavelength λ₁, Λ₂, ...
・ Λ _kIt will be measured every time. In equation (7) in this case
Corresponding formula becomes like formula (10), and also in formula (9)
The corresponding formula is as shown in formula (11).

[0043]

[Equation 10]

[0044]

[Equation 11]

In the above, the principal component spectral transmittance distribution is used, but the first to kth principal component spectra obtained by analyzing the spectral transmission density distribution of one or a plurality (for example, 10) of sample images. The spectral transmission density distribution can be estimated as follows using the transmission density distribution.

First, the spectral transmission density distribution D (λ) is converted into the principal component spectral transmission density distribution e ′ _j (λ) (j = 1, 2, ... K).
It is as follows when expressed by the linear sum of.

[0047]

[Equation 12]

On the other hand, the photometric value q _i (i = 1, 2, ... K) is expressed as follows.

[0049]

[Equation 13]

Between the transmittance and the transmission density, D (λ) =-
Since there is a relation of log ρ (λ), the equation (13) is changed to D
It is as follows when expressed using (λ).

[0051]

[Equation 14]

The coefficient a _j can be obtained by solving the equation (14) using a non-linear optimization method (for example, the Newton-Raphson method). The coefficient a _j and the principal component spectral transmission density distribution e ' _{If j} (λ) is used, the spectral transmission density distribution can be estimated from the equation (12). Further, the spectral transmittance distribution and the like can be estimated from the spectral transmission density distribution.

When the sensitivity distribution of the sensor is narrow band,
For example, in the case of one point of the specific wavelength λ _0, the equation (14) becomes as follows, so that the solution of a _j can be easily obtained.

[0054]

[Equation 15]

By the way, as described above, the number of the photometric value and the main component spectral transmittance distribution or the main component spectral transmittance density distribution are made the same, and the coefficient a ₁ is calculated by the computer using the above equations (9) and (14). , A ₂ , a ₃ , ..., A _k , it may be difficult to find a solution. In this case, the number of photometric values measured by the sensor may be increased by one to several, and calculation may be performed as described below. If the number of photometric values to be increased is too large, it is necessary to use a large number of interference filters as in the conventional case. Therefore, the number to be increased is preferably 1 or 2. In the following, in the example of estimating the spectral transmittance distribution using the principal component spectral transmittance distribution, the case where the photometric value is increased by one will be described as an example. The same applies when used. If the photometric value obtained by increasing the q _k + _1, (8) formula is as follows.

[0056]

[Equation 16]

Expression (16) is expressed as follows.

[0058]

[Equation 17]

When both sides of the equation (17) are multiplied by the transposed matrix [e] ^T of [e], [e] ^T [e] becomes a square matrix. Therefore, if this is set as [E], then (17) From the formula [a]
Can be expressed as:

[0060]

[Equation 18]

The relationship between the number of main component spectral transmission density distributions obtained by analyzing the spectral transmission density distribution of one type of negative film by the present inventor and the spectral residual of the estimated value with respect to the measured value,
When the relationship between the number of main component spectral transmission density distributions obtained by analyzing the spectral transmission density distributions of the 10 and 10 types of negative films and the spectral residual was examined, the results shown in FIG. 1 were obtained. As can be understood from FIG. 1, in the case of using the three principal component spectral transmission density distributions from the first principal component spectral transmission density distribution to the third principal component spectral transmission density distribution, the spectral residuals for one negative film are Small and good results have been obtained.

On the other hand, if the first to fourth principal component spectral transmission density distributions of the principal component spectral transmission density distribution obtained from ten kinds of samples are used, the spectral residual error is three for one negative film. This is almost the same as the case where the principal component spectral transmission density distribution of is used. Therefore, if a minimum of four main component spectral transmission density distributions are used for a plurality of negative films, the spectral transmission density distribution can be obtained without specifying the film type.

FIG. 2 shows the relationship between the number of main component spectral transmittance distributions obtained by analyzing the spectral transmittance distribution of one type of negative film and the spectral residual, and the spectral transmittance of 10 types of negative films. The relationship between the number of main component spectral transmittance distributions obtained by analyzing the distribution and the spectral residual is shown. As can be seen from FIG. 2, if the first to fourth principal component spectral transmittance distributions are used, the spectral transmittance distribution can be estimated with a relatively small spectral residual. In this case,
Since the estimation accuracy is better when the film type is specified, it is preferable to specify the film type when using four or five principal component spectral transmittance distributions.

Further, the sum up to 8 terms ρ (λ) = a ₁ · e ₁ (λ) + a ₂ · e ₂ (λ) + ... +
By using a ₈ · e ₈ a (lambda), namely the use of the eight main component spectral transmittance distribution of the first to eighth, the concentration of all kinds film without determining the type of film 0 It has been confirmed that the spectral transmittance distribution of the film can be estimated with an error of about 0.03.

The minimum value of the main component spectral transmittance distribution is 4 when the spectral transmittance distributions of a plurality of types of films are estimated without discriminating the type of film. this is,
If the number of main component spectral transmittance distributions is set to 3, the estimation accuracy deteriorates as described above. Further, if the number is 9 or more, the estimation accuracy is improved, but there is no great difference from the case of 8. Even considering all current color films and future unknown films, it is about 15 at maximum.

Therefore, the spectral distribution (spectral transmittance distribution or spectral density distribution) of a large number of sample films is analyzed to
If more than one main component spectral distribution is obtained in advance, and the image recorded on the recording material is decomposed into four or more colors for photometry, the image spectral distribution is based on the photometric data and the four or more main component spectral distributions. The distribution can be estimated with high accuracy.

The present invention uses the spectral distribution estimated as described above and the spectral sensitivity distribution of the copying material to measure the image with the photometric means having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material. An image density equivalent to the image density obtained by the above is obtained. For example, in this embodiment described below, the average density is used as the image density, and S (λ) in the formula (1) is replaced by the spectral sensitivity distribution S _p (λ) of the copying material,
Determine the average concentration. Further, the correction amount of three colors with respect to the average density is determined based on the photometric data of at least three colors of the photometric data of a large number of colors, and the average exposure is corrected by the correction amount to determine the copy exposure amount.

As described above, according to the present invention, the spectral distribution of the image can be estimated with high accuracy based on the photometric data, so that a large number of spectra can be obtained by using optical system elements such as a prism, a diffraction grating, and a spectral filter. There is no need to disassemble, the number of separated colors during photometry can be greatly reduced, and the optimum exposure amount can be determined with a small amount of photometric data. Further, since it is not necessary to perform photometry with parallel light and photometry can be performed using diffused light, the photometric means can be attached to the exposure section of the copying machine, and the copying machine can be downsized.

Further, since the correction amount for the average density is determined based on the photometric data of at least three colors out of the photometric data of many colors, it is not necessary to provide a separate photometric means to obtain the photometric data of three colors. Therefore, since the copying exposure amount is determined based on the data obtained by the photometry of the single photometry means, the copying apparatus can be further downsized and, for example, a long film is used as the recording material. In the equipment, switching of film transport (longitudinal feed,
It facilitates handling of films such as lateral feed) and conveyance of short films, and improves the operability of the copying machine. further,
The effect of light unevenness can be eliminated as compared with the case where the light transmitted through the film is diffused and color separation is performed.

It is preferable that the photometric means performs photometry with the light emitted from the light source for copying and transmitted or reflected the image recorded on the film. As a result, it is not necessary to provide a light source for photometry separately from the light source for copying, and the copying apparatus can be further downsized.

[0071]

【Example】

[First Embodiment] A first embodiment of the present invention will now be described in detail with reference to the drawings. The present invention is not limited to the numerical values described below. FIG. 3 shows, as a copying apparatus of the present invention, an automatic printer 10 for exposing an image recorded on a color negative film onto color paper.

The color negative film 14 set on the negative carrier 12 is conveyed to the exposure position by the negative carrier 12. A mirror box 16 is located below the exposure position.
And a lamp house 18 provided with halogen lamps. A dimming filter unit 20 is arranged between the mirror box 16 and the lamp house 18. The dimming filter unit 20 includes three CC filters, a Y (yellow) filter, an M (magenta) filter, and a C (cyan) filter, and an ND filter as a reference filter described later.

A DX code representing the type of the negative film 14 is recorded on the side edge of the negative film 14, and
A notch is formed in a portion corresponding to the image to be exposed. At the exposure position, a detector 22 composed of a light emitting element and a light receiving element is arranged so as to sandwich the side edge of the negative film 14, and the notch is detected by this detector 22.

Above the exposure position, the prism 24, the lens 26, the black shutter 28, and the color paper 30.
Are arranged in order. The prism 24 reflects a part of a light ray, which is emitted from the lamp house 18 and transmitted through the light control filter portion 20, the mirror box 16 and the negative film 14, to enter the photometric portion 32 at a substantially right angle. On the other hand, the light rays transmitted through the prism 24 are imaged on the color paper 30 by the lens 26.

The photometric section 32 includes three area sensors 34, 3
6, 38 and two prisms 40, 42 are provided.
The prism 40 laterally reflects a light ray having a light amount of ⅓ of the light rays reflected by the prism 24 to reflect the area sensor 34.
And let the rest of the rays pass through. The light ray transmitted through the prism 40 is incident on the prism 42. Prism 4
In 2, the half of the incident light is reflected sideways to be incident on the area sensor 36, and the remaining light is transmitted and incident on the area sensor 38. Therefore, the area sensors 34, 36, and 38 each receive a light beam having a light amount of ⅓ of the light beam entering the photometric unit 32.

A half mirror may be used instead of the prism 24. Further, instead of the prism 40, a mirror that reflects a light ray having a light amount of 1/3 of the incident light ray may be used, and instead of the prism 42, a light ray having a light amount of 1/2 of the incident light ray may be reflected. A half mirror may be used. Further, the area sensor 34 of the photometric unit 32,
The arrangement of 36 and 38 and the prisms 40 and 42 is not limited to the example shown in FIG. 3, and may be an arrangement in which light of substantially equal light quantity is incident on each area sensor. Further, in the above, the photometric unit 32 is arranged along the direction orthogonal to the emission direction of the light beam from the light source, but the photometric unit 32 is arranged at an angle other than 90 ° with respect to the light beam, that is, obliquely. Good.

The area sensor 38 is composed of a filter and a two-dimensional image sensor. FIG. 4 shows JP-A-62-18066.
The area sensor disclosed in Japanese Patent No. 0 is shown in which the filter has three substantially square blocks L on one substrate.
A large number of filters arranged in a letter shape are formed and configured. A large number of filters formed on the substrate are classified into three types according to transmission wavelength bands, and each transmission wavelength band has a center wavelength of about 430 nm (B) corresponding to the sensitivity wavelength bands of R, G, and B colors of the color paper 30. : Blue), about 510nm (G:
Green) and about 590 nm (R: red), and the half-widths are about 20 nm each.

The light incident on the area sensor 38 is applied to this filter, and is color-separated into different wavelength bands depending on the filter of the applied part, and is applied to the two-dimensional image sensor. The two-dimensional image sensor includes a large number of light receiving elements, and each light receiving element is arranged in a one-to-one correspondence with a substantially square block forming the filter,
The light passing through the single L-shaped filter is received by the three light receiving elements.

As shown in FIG. 4, the light transmitted through one pixel of the image recorded on the negative film 14 (the size of one pixel is about 1 mm both vertically and horizontally on the film) is substantially L to the filter.
The area for three letter filters is irradiated. Therefore, the light transmitted through the one pixel is received by the nine light receiving elements of the two-dimensional image sensor, and as is clear from FIG. 4, each of the nine light receiving elements has three light receiving elements. Light that has passed through the same type of filter will be received. Therefore, in the area sensor 38, the image recorded on the negative film 14 is separated for each pixel, and the light transmitted through each pixel is decomposed into each color of B, G, R to be measured. In this way, by using the sum of the outputs from the three light receiving elements of each color dispersedly arranged as the output value of one pixel, the position dependence of the three colors within one pixel, which is a problem of color separation by the area sensor, It has less sex.

The area sensor 34 has a center wavelength of about 43.
The filter is composed of three filters each having a half-value width of about 20 nm at 0 nm, about 510 nm and about 590 nm, and a two-dimensional image sensor. The area sensor 34 is capable of color-separating the incident light into the three wavelength bands by the filter and dividing the light into a large number by the two-dimensional image sensor for photometry.
Similarly, the area sensor 36 has a center wavelength of about 630 nm and about 67
It consists of three filters of 0 nm and about 750 nm, each with a half width of about 20 nm and a two-dimensional image sensor. it can. Therefore, the area sensors 34, 36
By the photometry, the color-separated photometric data for each wavelength band is obtained for the entire screen of the image or a part of the screen. Thus, in the photometric unit 32, the area sensors 34, 36, 3
8, the incident light is separated into 9 colors as shown in FIG.

The area sensors 34, 36 of the photometric unit 32,
38 is connected to a control device 46 composed of a microcomputer via a photometric data memory 44 for storing the photometric data obtained by the photometry of the photometric section 32. The photometric unit 32, the photometric data memory 44, and the control device 4
Reference numeral 6 constitutes an exposure amount determining device of the present invention. The control device 46 includes an input / output port 48 and a central processing unit (CPU) 5
0, a read only memory (ROM) 52, a random access memory (RAM) 54, and a bus 56 including a data bus and a control bus connecting these.

In the ROM 52, the program of the exposure amount control routine described below and the eight main component spectral transmittance distributions represented by the transmittances with respect to the wavelengths shown in FIGS. ) E ₁ (λ), e ₂ (λ), e ₃
(Λ), ... E ₈ (λ) are stored. The main component spectral transmittance distributions of FIGS. 6 to 8 are obtained by analyzing the spectral transmittance distributions of 10 kinds of films. Also,
In the ROM 52, the spectral energy distribution of the halogen lamp in the lamp house 18, the spectral sensitivity distribution Si (λ) of the color paper 30 used, the area sensors 34, 36, 3 are provided.
8 spectral sensitivity distributions are stored in advance.

Instead of the above-mentioned main component transmittance distribution, as shown in FIGS. 18 to 20, eight main component transmittance density distributions (normalized to a density of 1.0) represented by the transmission density with respect to the wavelength are used. It may be stored.

The control device 46 is connected to the photometric data memory 44 via the input / output port 48, controls the writing and reading timing of the image data memory 44, and fetches the photometric data stored in the photometric data memory 44. .. Further, the input / output port 48 of the control circuit 46 is
Drive circuit 5 for driving the detector 22 and the negative carrier 12
8. A drive circuit 60 for driving each CC filter of the dimming filter unit 20 and a drive circuit 62 for driving the black shutter 28 are connected, and the control circuit 46 operates the negative carrier 12 according to the presence or absence of notch detection. To control
At the time of exposure, the light control filter unit 20 and the black shutter 28
Control the drive of. A keyboard 64 for inputting data and a CRT 66 for displaying processing results are connected to the input / output port 48.

Next, the operation of the first embodiment will be described with reference to the flow charts of FIGS. 9 and 10. First, referring to the flowchart of FIG. 9, the area sensor 3 of the photometric unit 32
The calibration processing of Nos. 4, 36 and 38 will be described.
This calibration process is for correcting fluctuations in the light quantity of the light source lamp, uneven light quantity and color unevenness of the light incident on the photometric unit 32, variations in the sensitivity of each area sensor, and the like. It is executed when the power is turned on or when the light source lamp is replaced.

In step 100, the reference filter of the dimming filter section 20 is inserted on the optical path of the light emitted from the lamp house 18. As a result, the area sensors 34, 3
The light amount of the light incident on each of 6 and 38 is reduced, and the output signal of each area sensor is prevented from being saturated with respect to the incident light amount. In step 102, the light source lamp in the lamp house 18 is turned on. Along with this, the light transmitted through the reference filter is incident on each area sensor of the photometric unit 32.

The light incident on the photometric unit 32 is color-separated into nine kinds of wavelength bands by the filters of the area sensors 34, 36 and 38, and in the next step 104, the wavelengths of the respective wavelength bands are separated by the area sensors 34, 36 and 38. Measure the amount of light at. In step 108, the data measured in step 104 is compared with the spectral energy distribution of the light source lamp stored in advance in the ROM 52, and the differences in the nine types of wavelength bands are calculated as the calibration data set in each area sensor. To do. Based on the calculated sub, calibration data for correcting light amount fluctuation, light amount unevenness, color unevenness, sensor sensitivity variation, etc. are calculated and stored in the RAM 54, and this calibration process is terminated.

Next, the exposure control process of the first embodiment will be described with reference to the flowchart of FIG. Step 120
Then, drive the negative carrier 12 via the drive circuit 58,
The negative film 14 is conveyed. During this time, the detector 22 detects the presence or absence of a notch formed in the negative film 14. In step 122, it is judged whether or not the presence of the notch is detected by the detector 22. While the determination in step 122 is negative, steps 120 and 122 are repeated, and the negative film 14 is continuously conveyed.

When the presence of the notch is detected and the determination in step 122 is affirmative, the transport of the negative film 14 is stopped,
When the image recorded on the negative film 14 is stopped at the exposure position, the process proceeds to step 124. In step 124, the light that has passed through the image and is incident on the photometric unit 32 is color-separated into the respective wavelength bands for photometry. This photometry is performed by scanning a large number of light receiving elements of each area sensor and taking in the photometric data output from each light receiving element.

In step 126, the calibration data obtained in the calibration process is fetched, the photometric data is calibrated by the calibration data, and the result is stored in the photometric data memory 44. As a result, errors due to fluctuations in light amount, light amount unevenness, color unevenness, and variations in sensor sensitivity are eliminated from the photometric data. In the next step 128, the eight principal component spectral transmittance distributions are stored in the ROM 5
In step 130, the spectral transmittance distribution T (λ) of the entire screen of the image is acquired using the photometric data, the main component spectral transmittance distribution imported from the ROM 52, and the spectral sensitivity distribution of each area sensor as described above. ) (Or spectral transmission density distribution) is estimated.

The spectral transmittance distribution or the spectral transmission density distribution estimated in this way coincides with the actual measured value with high accuracy as shown in FIG. 12 as an example. FIG. 12 shows A, B,
It is a plot of the measured and estimated values of the spectral transmission density distribution for images of C and D4 types, which is 6 at around 440 nm.
An error within the allowable range occurs in the wavelength range near 20 nm and 720 nm, but it is almost the same in other bands. Although the spectral distribution of the entire screen of the image is estimated in the above, the spectral distribution of a predetermined region (a part of the screen) selected by a predetermined method may be estimated.

In the next step 132, the spectral sensitivity distribution Si (λ) of the color paper 30 is fetched from the ROM 52.
In step 134, the spectral sensitivity distribution S of the color paper 30 is
An image density equivalent to the image density obtained by photometry by the photometry unit 32 having the same spectral sensitivity distribution as i (λ) is obtained. In this embodiment, the average density MD1i is used as the image density, and the spectral transmittance distribution T of the image estimated in step 130 is used.
(Λ) and the spectral sensitivity distribution Si (λ) of the color paper 30 are used for the calculation according to the following equation (19).

[0093]

[Formula 19]

However, i represents any one of R, G and B, λmin is the minimum value of the addition section (corresponding to one of the R, G and B wavelength bands), and λmax is the maximum value of the addition section. Is. As described above, Si (λ) is the spectral sensitivity distribution of color paper, but in the above formula (19), it acts as a coefficient for weighting the spectral transmittance distribution of the image according to the spectral sensitivity distribution of the color paper 30, An average density MD1i equivalent to the average density obtained by photometry with the photometric means having a spectral sensitivity distribution that matches the spectral sensitivity distribution of the color paper 30 is obtained.

When changing the type of color paper 30, a plurality of types of color paper 3 are stored in the ROM 52 in advance.
The spectral sensitivity distribution Si (λ) of 0 may be stored in advance and the spectral sensitivity distribution Si (λ) of the color paper 30 to be used may be selected by the keyboard 64. Alternatively, a plurality of spectral sensitivity distributions Si (λ) stored in an external storage means such as a floppy disk may be selected. Seed color paper 3
The spectral sensitivity distribution of 0 may be taken into the RAM 54 as needed.

At the next step 136, the average density MD1i
Calculate the correction amount to correct. This correction amount calculation process will be described in detail with reference to the flowchart of FIG. 11. In step 160, of the photometric data stored in the photometric data memory 44, the photometry of the three colors obtained by the photometry of the area sensor 38 is performed. Data D2ij is transferred to RAM5
Incorporate on 4. In the next step 162, the average density MD2i of the captured photometric data D2ij of the three colors is changed to the next (2
Operate according to the equation (0).

[0097]

[Equation 20]

However, n is the total number of pixels of the image, i is R,
One of G and B, and j represents a number given to each pixel.
In step 164, the values stored in advance in the ROM 52, for example, the low-density portion photometric data MIN (R), MIN (G), and MIN (B) of the three colors are calculated from the average mask density and stored in the RAM. The average mask density is obtained by averaging the mask density or average minimum density of various films. A predetermined value α (for example,
(Value of 0 to 0.6) Compare the large value with the lowest density value of the three-color photometric data or the average value of the three-color photometric data, and (average mask density + α)> (lowest density value of the three-color photometric data Or the average value of the three-color photometric data), the lowest density value of the three-color photometric data or the average value of the three-color photometric data is set as the low-density portion photometric data. On the other hand, (average mask density +
When α) <(the lowest density value of the three-color photometric data or the average value of the three-color photometric data), a value larger by a predetermined value α than the average mask density is set as the low-density portion photometric data.

At the next step 166, the low-density portion photometric data MIN (R) and MIN are obtained from the respective three-color photometric data.
The three-color corrected photometric data R, G, B are calculated by subtracting (G) and MIN (B). The corrected photometric data has similar characteristics regardless of the film type as described in Japanese Patent Laid-Open No. 3-230148.

In the next step 168, the three-color standardized photometric data is calculated by converting the corrected photometric data R and B into the density of G using the standardization curve shown in FIG. 13 and normalizing (normalizing). To do.

In this standardization, the film density and gradation balance differ depending on the exposure level and the film type, so that when the same subject is photographed, the image density and color differ depending on the exposure level and film type. Is a process for correcting the same subject to obtain a constant density and color on the negative film regardless of the exposure level and film type. A curve showing the relationship between the average value of the photometric data G and the average value of the photometric data R stored in the RAM, and a curve showing the relationship between the average value of the photometric data G and the average value of the photometric data B (FIG. 13). A standardization table is created based on

[0102] The above using the normalization table correction photometric data R, while B is converted to the concentration of G, as shown in FIG. 13, for example, R ₂ to R average value of the correction photometric data of ₃ R ₃ 'Is converted to the average value G ₃ ' of G ₂ and G _3, and B ₂ ~ B
The average value B ₃ '(not shown) of the corrected photometric data of ₃ is also converted into the average value G ₃ '. At this time, the corrected photometric data G is used as it is without conversion. As the standardizing method, in addition to the above, Japanese Patent Laid-Open Nos. 56-1039 and 62-14415 are available.
The method described in Publication No. 8 can be used.

By standardizing such corrected photometric data, the same color coordinates can be used even if the film density and film type are different. Also, the origin of the coordinates can be set to any color. Assuming that the average value of the photometric data of a large number of films is gray, the standardized data of the gray subject will have the same density of three colors by the above standardization. Actually, the average value of the photometric data of a large number of films is slightly different from that of gray, so the amount should be corrected by an amount corresponding to the difference.

In the next step 170, as shown in FIG. 14, the color coordinate with the difference R-G between the standardized data R and G as the horizontal axis and the difference GB between the standardized data G and B as the vertical axis. The three-color standardized data is classified by determining which of the color areas A _a including the origin and the color area A _b other than the color area A _a defined above belongs to the three-color standardized data. To do.
The three-color standardized data is classified with the boundary between the color area A _a and the color area A _b as a boundary. Therefore, the three-color standardized data belongs to an area having a small color difference from the reference value (origin). And data belonging to a region having a large color difference from the reference value.

The following table shows an example of color areas, three-color standardized data classified for each color area, and three-color photometric data corresponding to the three-color standardized data.

[0106]

[Table 1]

In step 172, the 3-color photometric data corresponding to the 3-color standardized data belonging to the color area A _a having _a small color difference from the reference value is selected and stored in the RAM 54. In the next step 174, the selected three-color photometric data is arithmetically averaged by the equation (20) or the like to select the selected average density MD3.
i is calculated. When the three-color standardized data is classified by the coordinates with the color ratio as an axis, the three-color photometric data corresponding to the three-color standardized data belonging to the color area having the smaller color ratio from the reference value is selected, and the three-color photometric data are selected. The color photometric data is averaged to calculate the selected average density MD3i.

At step 176, the average density MD2i of the three-color photometric data is selected, and the selected average density MD3i of the three-color photometric data is selected.
The correction amount K2i is calculated based on The correction amount K2i can be calculated by the following equation (21).

[0109]

[Equation 21]

Thus, the calculation process of the correction amount K2i is completed,
The process moves to step 138 of the flowchart of FIG.
It should be noted that the calculation of the correction amount using the three-color photometric data is not limited to the above, and it is not limited to the above.
It is possible to apply the exposure amount determination methods described in JP-A 2-93450 and JP-A-3-46648.

In step 138, the correction amount K2i is corrected so that the influence of the difference between the spectral sensitivity distribution of the area sensor 38 and the spectral sensitivity distribution of the color paper 30 is eliminated from the correction amount K2i calculated above. As an example, JP-A-3-2301
As described in Japanese Patent Application Laid-Open No. 48-48119 and Japanese Patent Application Laid-Open No. 1-142719, the spectral sensitivity distribution of the area sensor 38 is the same as that of the color paper 3.
The correction is not always necessary when the spectral sensitivity distribution is close to 0, but when the spectral sensitivity distribution of the area sensor 38 is significantly different from the spectral sensitivity distribution of the color paper, the correction amount K2i also has a large error. However, it is impossible to obtain a proper exposure amount.

That is, the process of dividing an image into a large number (for example, for each pixel), dividing each divided into a large number of colors and measuring the light, and dividing each divided into three colors by the area sensor 38 Based on the data obtained by converting the photometric data of a large number of colors according to the spectral sensitivity distribution of color paper and the photometric data of three colors for a single image or multiple images, If the image density (D1i) obtained from the converted photometric data is plotted on the vertical axis and the image density (D2i) obtained from the photometric data of the three colors is plotted on the horizontal axis, the area sensor 38
When the spectral sensitivity distribution of is sharper than the spectral sensitivity distribution of the color paper 30 (when the full width at half maximum is small), the gradient becomes larger than 1 as shown in FIG. 15 as an example.
In this case, the correction amount K2i can be obtained by simply comparing the average density (M1Di) obtained from the data obtained by converting the photometric data of the multiple colors and the average density (MD2i) obtained from the photometric data of the three colors. It is difficult to correct to a proper value.

Therefore, the relationship as shown in FIG. 15 is obtained in advance, and the correction amount K2i is corrected in step 138 based on this relationship. This correction is equivalent to obtaining a value on the X axis (hereinafter, referred to as corrected correction amount K1i) when the value on the Y axis is set as the correction amount K2i in the above relationship as shown in FIG. Specifically, based on the above relationship, D1
The relational expression for i may be obtained, and the correction amount K2i may be converted (corrected) into the corrected correction amount K1i by the relational expression. Further, the relational expression for the average density obtained by quantizing the photometric data into a plurality of density levels may be obtained based on the relationship shown in FIG.

In the above, the correction amount K2i is converted into the correction correction amount K1i, and the exposure control amount X1i is obtained in the next step based on the correction correction amount K1i. However, the exposure control is performed based on the three-color photometric data. The amount X2i may be obtained and converted in the same manner as above to obtain the exposure control amount X1i. In this case, the exposure control amount X1i is calculated (22)
Also for the average density MD1i of the first term of the equation (described later), 3
It can be obtained by correcting the average density of the color photometric data using the relationship shown in FIG. 15. Among the photometric data of a large number of colors, the photometric data other than the three colors is estimated in the spectral distribution and the relationship shown in FIG. Will only be used to derive

The relationship shown in FIG. 15 can be obtained without necessarily measuring and plotting each pixel. For example, at least two parts of the image (for example, the central part and the peripheral part, the maximum density part and the minimum density part, the density part higher than the intermediate density and the density part lower than the intermediate density) are measured,
It can be determined by plotting each based on the photometric data. Alternatively, the density of the entire image may be measured, plotted based on the photometric data, and the relationship may be approximately obtained as a straight line connecting the plotted point and the origin.

At the next step 140, the exposure control amount X1i is calculated according to the following equation (22) based on the correction correction amount K1i obtained at step 138 and the average density MD1i obtained from the photometric data of a large number of colors.

X1i = MD1i + F · K1i (22) However, F: a value represented by a constant (for example, 1.0) or a function In step 142, the exposure amount is determined based on the exposure control amount X1i determined in step 140. .. The exposure amount is determined based on the following equation (22).

LogEi = Si · Ai (X1i−Dφi) + Ki (23) where i: one of R, G, and B logE: logarithm of exposure amount Dφi: density of reference negative film Ki: color Constant determined by paper and printer Si: Slope control coefficient (= 0.5 to 2.0) Ai: Color correction coefficient (≈1.0) In step 144, the image positioned at the exposure position is exposed to the color paper 30 with the exposure amount obtained above. As described above, the drive of the light control filter unit 20 and the black shutter 28 is controlled. In the next step 146, it is determined whether or not exposure of all the images on the negative film 20 set in the automatic printer 10 has been completed. If the determination in step 146 is negative, the process returns to step 120, the next image is positioned at the exposure position, and photometric processing, exposure amount determination, and exposure processing are performed.

As described above, since the spectral distribution of the image is estimated based on the photometric data of 9 colors in the above embodiment, it is not necessary to perform color separation by using optical system elements such as a prism, a diffraction grating and a spectral filter. The optimal exposure amount can be determined with a small amount of photometric data. Further, since it is not necessary to measure the light with parallel light, and the light can be measured with diffused light, the automatic printer 10 can be downsized.

Further, since the correction amount for the basic exposure amount is determined based on the photometric data of three colors of one area sensor 38 among the three area sensors for dividing into nine colors and performing photometry, 3 It is not necessary to provide a separate photometric means to obtain color photometric data, the automatic printer 10 can be further downsized, and the transfer of the negative film 14 can be switched (longitudinal feed, horizontal feed, etc.), piece negative transfer, etc. Is easy to handle.

[Second Embodiment] Next, a second embodiment of the present invention will be described. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the second embodiment, the filters of the area sensors 34 and 36 of the photometric unit 32 are arranged in the same manner as the filter of the area sensor 38 so that three substantially square blocks are arranged in an L shape on one substrate. A large number of filters having different shapes are formed (see FIG. 4), and each pixel is capable of color separation into three types of wavelength bands for photometry.

The operation of the second embodiment will be described with reference to the flow chart of FIG. 16. In the photometry of step 124, the area sensors 34, 36 and 38 divide the image into each pixel and color the respective wavelength bands. Disassemble and measure light. In step 130, the spectral distribution (either spectral transmittance distribution or spectral transmittance density distribution) Tj (λ) is estimated for each pixel based on the photometric data obtained thereby. The j is a number conveniently assigned to each pixel to distinguish each pixel.

At step 134, the average density is calculated based on the spectral distribution Tj (λ) obtained for each pixel and the spectral sensitivity distribution of the color paper 30 fetched at step 132. When the estimated spectral distribution is the spectral transmittance distribution, the average density Di can be calculated by the following equation (24).

[0125]

[Equation 22]

In the above equation (24), n is the number of target pixels for obtaining the average density, but it is not necessary to target all the pixels forming the image. For example, the pixel selected in the same manner as in FIG. May be targeted. The processing after step 136 is the same as that in the first embodiment.

In the above-described embodiment, the photometric unit 32 performs color separation for photometry as shown in FIG. 5, but the present invention is not limited to this, and for example, as shown in FIG. The spectra resolved by the sensor may overlap. As shown in FIG. 17B, the area sensor 3
It is also possible to divide each of the color components 4 and 36 into two colors and perform photometry. In this case, the photometric unit 32 separates the light into seven colors and performs photometry, so that the spectral distribution of the image is obtained from a maximum of seven principal component spectral distributions. Further, the image density is not limited to the average density of the entire image or a partial area of the image, but of the selected pixel (at least two or more pixels) such as the pixel from which the low density portion of the image is removed. Values included in average values and cumulative histograms are also included.

The sensor for photometry is not limited to the area sensor, and a line sensor or the like may be used. In this case, the image may be irradiated with slit light, the slit light transmitted through the image may be incident on the line sensor, and the negative film 14 may be gradually moved to scan the image with the slit light.

In the above embodiment, the photometric data for each color obtained by dividing the light into three colors by the area sensor 38 to obtain the correction amounts for the three colors is used, but the correction amount for each color is measured for a plurality of colors. It may be obtained from a weighted average value of data.
For example, in FIG. 17A, a weighted average value of photometric values of 670 nm, 710 nm, and 750 nm is used instead of the R photometric value of 710 nm. Similarly, as the G and B photometric values, values obtained from two or more photometric values may be used. In this case, the three colors can obtain characteristics closer to the spectral sensitivity distribution of the copying material.

Further, although the exposure amount determining apparatus of the present invention is integrally attached to the automatic printer 10 as a copying apparatus in the above, it may be provided separately from the copying apparatus.

In the above description, the automatic printer 10 for copying the image recorded on the negative film 14 onto the color paper 30 is described as an example of the copying apparatus, but the present invention is not limited to this. For example, it can be applied to a copying machine for copying a positive image recorded on a reversal film onto a color copying material, and a copying machine for copying a color reflection original. Further, the present invention can be applied to the determination of the exposure amount of a copying apparatus that copies an image by digital means such as laser light or CRT light, as well as a copying apparatus that copies an image by surface exposure.

[0132]

As described above, according to the present invention, the image recorded on the recording material is divided into a large number of pieces, and the light is separated into a large number of four or more colors. An image density equivalent to the image density obtained by estimating the distribution and using the estimated spectral distribution and the spectral sensitivity distribution of the copying material to measure the image with a photometric device having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material. In addition, the amount of correction is determined on the basis of the photometric data of at least three colors among the photometric data of a large number of colors, and the copy exposure amount is determined by correcting the image density by the correction amount. An excellent effect that the optimum exposure amount can be determined from the data and the apparatus can be downsized is obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between the number of eigenvectors and a spectrum residual for explaining the operation of the present invention.

FIG. 2 is a diagram showing a relationship between the number of eigenvectors and a spectrum residual.

FIG. 3 is a schematic configuration diagram of an automatic printer according to the present embodiment.

FIG. 4 is a plan view showing a pattern formed on a substrate of a filter that constitutes an area sensor together with a two-dimensional image sensor.

FIG. 5 is a diagram showing a spectral sensitivity characteristic as a photometric unit.

FIG. 6 is a diagram showing first to third main component spectral transmittance distributions of a plurality of negative films.

FIG. 7 is a diagram showing fourth to sixth main component spectral transmittance distributions of a plurality of negative films.

FIG. 8 is a diagram showing seventh and eighth principal component spectral transmittance distributions of a plurality of negative films.

FIG. 9 is a flowchart illustrating an area sensor calibration process.

FIG. 10 is a flowchart illustrating an exposure control process of the first embodiment.

FIG. 11 is a flowchart illustrating details of a correction value calculation process.

FIG. 12 is a diagram showing a comparison between an estimated spectral transmission density distribution and an actually measured spectral transmission density distribution.

FIG. 13 is a diagram showing a standardization curve.

FIG. 14 is a diagram showing color coordinates for classifying three-color standardized data.

FIG. 15 is a diagram showing a relationship between photometric data obtained by dividing light into a large number of colors and performing photometry, and converting the data according to a spectral sensitivity distribution of color paper, and photometric data obtained by dividing light into three colors and performing photometry.

FIG. 16 is a flowchart illustrating an exposure control process of the second embodiment.

17A and 17B are diagrams showing another example of the photometric spectrum of the photometric unit.

FIG. 18 is a diagram showing first to third main component spectral transmission density distributions of a plurality of negative films.

FIG. 19 is a diagram showing fourth to sixth main component spectral transmission density distributions of a plurality of negative films.

FIG. 20 is a diagram showing seventh and eighth principal component spectral transmission density distributions of a plurality of negative films.

[Explanation of symbols]

 10 Automatic Printer (Copier) 14 Negative Film (Recording Material) 24 Prism 30 Color Paper 34 Area Sensor 36 Area Sensor 38 Area Sensor 44 Photometric Data Memory 46 Controller

Claims (6)

[Claims] 1. A photometric device that divides an image recorded on a recording material into a large number and divides the image into a predetermined number of four or more colors to perform photometry, and a multi-color image obtained by the photometry of the photometric device. Estimating the spectral distribution of each pixel obtained by dividing the image into a large number of pixels or the entire screen of the image or a part of the screen using a storage unit that stores the photometric data and the photometric data of multiple colors stored in the storage unit And an image density equivalent to the image density obtained by photometrically measuring the image by using the estimated spectral distribution and the photometric means having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material using the estimated spectral distribution and the spectral sensitivity distribution of the copying material. An image density calculating means for obtaining an image density; a correction amount determining means for determining a correction amount of three colors with respect to the image density based on the photometric data of at least three colors among the stored multicolor photometric data; An exposure amount determining device for a copying machine, comprising: an exposure amount determining device that corrects an image density by the correction amount determined by the correction amount determining device to determine a copy exposure amount. 2. The estimating means obtains a weighting coefficient to be given to each of the plurality of principal component spectral distributions, based on the photometric data of the multiple colors and a plurality of principal component spectral distributions obtained in advance, and the weighting factor is calculated. 2. The exposure amount determining apparatus for a copying apparatus according to claim 1, wherein the spectral distribution of the image is estimated by obtaining a linear sum of the plurality of main component spectral distributions using a coefficient. 3. The exposure amount determining apparatus for a copying apparatus according to claim 1, wherein the photometric means measures the light by light emitted from a light source for copying and transmitted or reflected the image. 4. The photometric means is composed of two or more area sensors for dividing the image into a large number and dividing the image into two or more colors to perform photometry. An exposure amount determining apparatus for a copying apparatus according to item 1. 5. At least one of the area sensors comprises:
5. The exposure amount determination of the copying apparatus according to claim 4, wherein the copying material has a maximum sensitivity in a wavelength band corresponding to the R, G, and B color sensitivity wavelength bands and performs photometry in the corresponding wavelength band. apparatus. 6. The photometric means comprises a plurality of line sensors, and divides the image into a large number of pieces to divide into a large number of four or more colors for photometry.
An exposure amount determining apparatus for a copying apparatus according to any one of 1.