JPH05346628A - Method and device for exposure determination of copying device - Google Patents

Abstract

PURPOSE:To obtain the exposure determination method for the copying machine and device therefor which can determine an optimum exposure with a little photometric data and can be reduced in the size of the device. CONSTITUTION:The image is divided into many pieces of picture elements and the respective picture elements are metered by sepn. to 9 colors (step 124). The picture elements to be used for determining the exposure are selected in accordance with the photometric data on three colors in the photometric data obtd. by photometry (steps 128 to 138). The average value of the photometric data of the selected picture elements is computed for each of the respective colors (step 140). The plural main component spectral distributions which are previously determined are taken in and the spectral distribution of the region consisting of the selected picture elements is estimated in accordance with the average value and the main component spectral distribution (steps 142, 144). The spectral sensitivity distribution of color paper is taken in (step 146). The average density (exposure controlled quantity) equiv. to the average density determined by photometry with the sensors having the spectral sensitivity distribution equal to the color paper is determined for this region and the exposure is determined in accordance with this average density (steps 148, 150).

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 method for a copying machine and an exposure amount determining apparatus for a copying machine to which this exposure amount determining method can be applied.

[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, An exposure amount control device (see Japanese Patent Laid-Open No. 3-230148) has been proposed in which the correction amount is obtained by a sensor and the exposure amount is determined by both.

In the above exposure amount control device, the interference filter is configured to change the thickness of the interference film continuously or stepwise so as to change the wavelength to be dispersed depending on the light irradiation portion, and the two-dimensional image sensor. Since it constitutes the first sensor, it is possible to measure light using diffused light.
Since it is necessary to provide two photometric units, it is difficult to downsize 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.

In connection with this, in the method of determining the exposure amount of the image copying apparatus proposed by the present applicant (Japanese Patent Laid-Open No. 3-46648), the three-color standard obtained by converting the three-color photometric data according to the standardization condition is adopted. As standardized data, the three-color standardized data is compared with a reference value to classify the three-color standardized data, and the exposure amount is determined based on the average density of the three-color photometric data selected according to the classification. As a result, an appropriate exposure amount is obtained regardless of the type of film on which the image is recorded, but no consideration is given to making the spectral sensitivity distribution of the photometric means coincide with the spectral sensitivity distribution of the copying material.

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).

[0012]

[Equation 1]

Therefore, the spectral sensitivity distribution S of the copying 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 copy 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 based on the calculation of the 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.

Further, in order to accurately determine the exposure amount, the image of each pixel is divided by each sensor of the photometry section, each divided pixel is decomposed into a large number of colors, and photometry is performed to obtain a spectral distribution of all pixels. It is preferable to determine based on the spectral distribution of each pixel after measuring or estimating, but there is a problem that it takes a calculation time to calculate the spectral distribution for each pixel,
Furthermore, the position of each pixel when the image is divided by each sensor must be exactly the same as the actual position. To satisfy this, the alignment of each sensor (so-called registration) is highly accurate. Therefore, it takes a lot of time to adjust.

The present invention has been made in consideration of the above facts, and it is possible to determine the optimum exposure amount with a small amount of photometric data, and to reduce the size of the device. The purpose is to obtain a method for determining the quantity.

[0018]

In order to achieve the above object, the invention according to claim 1 divides an image recorded on a recording material into a large number of pixels, and each pixel has four or more predetermined colors. At least 3 of the photometric means for dividing into a large number of colors for photometry, the storage means for storing the photometric data of the multicolors obtained by the photometry of the photometric means, and the photometric data of the multicolors stored in the storage means Pixel selecting means for selecting a pixel used for determining the exposure amount based on the color photometric data, and an average value calculating means for calculating an average value of the photometric data of the pixels selected by the pixel selecting means for each color. ,
A spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material is obtained for the region including the selected pixel by using the first weighting factor obtained from the spectral sensitivity distribution of the copying material and the average value of the photometric data for each color. It has an average density calculating means for obtaining an average density equivalent to the average density obtained by photometry by the photometric means, and an exposure amount determining means for determining an exposure amount based on the average density.

Further, the average density calculating means includes an estimating means for estimating a spectral distribution of a region including the selected pixels based on an average value for each color of the photometric data of the selected pixels, and the estimated spectral distribution. It is preferable to calculate the average density by using and the first weighting factor.

The estimating means obtains a second weighting coefficient based on the average value of each color of the photometric data of the selected pixel and a plurality of predetermined principal component spectral distributions, and the second weighting coefficient is obtained. It is preferable to estimate the spectral distribution of the region including the selected pixels by obtaining the linear sum of the plurality of principal component spectral distributions using the weighting coefficient.

According to a fourth aspect of the present invention, a photometric means for dividing an image recorded on a recording material into a large number of pixels, dividing each pixel into a predetermined number of four or more colors, and performing photometry, An exposure amount of the photometric data is determined on the basis of storage means for storing the photometric data of a large number of colors obtained by the photometry of the photometric means, and photometric data of at least three colors of the photometric data of a large number of colors stored in the storage means. Pixel selecting means for selecting a pixel to be used for, the estimating means for estimating the spectral distribution of each of the selected pixels based on the photometric data of the pixel selected by the pixel selecting means, and the estimated spectrum of each pixel The distribution and the first weighting factor obtained from the spectral sensitivity distribution of the copying material are used to measure the region consisting of the selected pixels with a photometric means having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material. An average density calculation unit to determine the average density and average density equivalent obtained has an exposure amount determining means for determining the exposure amount based on the average density.

Further, the photometric means may be composed of two or more area sensors which divide the image into a large number of pieces and decompose each into two or more colors to perform photometry.

When the photometric means is composed of two or more area sensors, at least one of the area sensors is
It can be configured to perform photometry of three colors of R, G and B.

The area sensor for measuring R, G, B colors can be constructed so as to have the maximum sensitivity in the wavelength band corresponding to the sensitivity wavelength bands of the R, G, B colors of the copy material.

Further, the selecting means can select the pixel based on the photometric data obtained by the photometry of the area sensor which performs photometry of the R, G and B colors.

Further, the photometric means is composed of a plurality of line sensors, and the above-mentioned image can be divided into a large number and divided into a large number of four or more colors for photometry.

According to a tenth aspect of the present invention, the image recorded on the recording material is divided into a large number of pixels, each pixel is decomposed into a large number of predetermined four or more colors, and photometry is performed. A pixel for which the photometric data is used for determining the exposure amount is selected based on the photometric data of at least three colors of the data, and the exposure amount is determined using the photometric data of a large number of colors of the selected pixel.

The exposure amount is obtained by estimating the spectral distribution of the area including the selected pixels by using the photometric data of a large number of colors of the selected pixels, and using the estimated spectral distribution and the spectral sensitivity distribution of the copying material. It is possible to obtain an average density equivalent to the average density obtained by photometry with a photometric means having a spectral sensitivity distribution equal to that of the copying material for the region consisting of the selected pixels, and to make a determination based on the average density. it can.

As the exposure amount, the spectral distribution of each selected pixel is estimated based on the photometric data of a large number of colors of the selected pixel, and the estimated spectral distribution of each pixel and the spectral sensitivity distribution of the copying material are used. It is possible to obtain an average density equivalent to the average density obtained by photometry with a photometric means having a spectral sensitivity distribution equal to that of the copying material for the region consisting of the selected pixels, and to make a determination based on the average density. it can.

The spectral distribution can be estimated using a plurality of predetermined principal component spectral distributions.

[0031]

According to the first aspect of the invention, the image recorded on the recording material is divided into a large number of pixels, each pixel is decomposed into a predetermined number of four or more colors, and photometry is performed. A pixel whose photometric data is used to determine the exposure amount is selected based on the photometric data of at least three colors of the data. This pixel selection method is disclosed in Japanese Patent Laid-Open Nos. 2-93450 and 2-
The methods described in Japanese Patent No. 93450, Japanese Patent Laid-Open No. 61-198144, etc. can be applied, whereby, for example, high-saturation pixels that adversely affect the determination of the exposure amount can be removed.

Next, the average value of the photometric data of the selected pixel is calculated for each color, and the selected value is selected using the first weighting factor obtained from the spectral sensitivity distribution of the copying material and the average value of each color. An average density equivalent to the average density obtained by photometry with a photometric means having a spectral sensitivity distribution equal to that of the copying material is obtained for a region including the pixels. As described in claim 2, the calculation of the average density is performed by estimating the spectral distribution of the region including the selected pixels based on the average value of the photometric data of the selected pixels for each color. This can be done by using the distribution and the first weighting factor.

Hereinafter, 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).

[0035]

[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.

[0037]

[Equation 3]

Principal axis vector e is obtained by performing 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.

[0039]

[Equation 4]

Since the matrix Σ is a symmetric matrix, the eigenvalues are 0 or more, and the largest eigenvalues are 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 ],

[0042]

[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

[0044]

[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 of the equation (2) corresponding to the second weighting factor of the present invention. .. Also,
Since the density is the logarithm of the transmittance, the spectral transmission density distribution can also 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.

[0047]

[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,

[0049]

[Equation 8]

[0050]

[Equation 9]

[Mathematical formula-see original document]
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
It Also, from this spectral transmittance distribution,
The spectral transmission distribution can be estimated. Therefore, billing
As described in item 3, photometric data of the selected pixel
Average value for each color and a plurality of predetermined principal component spectral components
Weighting factor a based on the cloth₁, A₂... a _kSeeking
Therefore, using this weighting factor,
If the sum is calculated, the spectral distribution of the area consisting of the selected pixels
Can be estimated.

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).

[0053]

[Equation 10]

[0054]

[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 distributions 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.

[0057]

[Equation 12]

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

[0059]

[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).

[0061]

[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.

[0064]

[Equation 15]

By the way, as described above, the number of photometric values and the main component spectral transmittance distribution or the main component spectral transmission 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.

[0066]

[Equation 16]

Expression (16) is expressed as follows.

[0068]

[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:

[0070]

[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, by using the first to fourth principal component spectral transmission density distributions of the principal component spectral transmission density distribution obtained from ten kinds of samples, 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 ten 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.

In addition, the sum of the eight 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 images is analyzed to obtain four or more main component spectral distributions in advance, and the image recorded on the recording material is colored in four colors. If the above-described decomposition is performed and photometry is performed, the spectral distribution of the image can be estimated with high accuracy based on the photometric data and the four or more main component spectral distributions.

According to the first to third aspects of the present invention, the average value of each color of the photometric data of the pixel is calculated, and the first weighting coefficient obtained from the spectral sensitivity distribution of the copying material and each color of the photometric data are calculated. The average density equivalent to the average density obtained by photometry with a photometric means having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material is calculated by using, for example, S (λ) of the formula (1). The exposure amount is determined by the formula replaced with the spectral sensitivity distribution S _p (λ) of the copying material.

As described above, the spectral distribution of the image can be estimated with high accuracy from the photometric data obtained by performing photometry by decomposing into four or more colors, and an appropriate exposure amount can be obtained from this spectral distribution. Since it is no longer necessary to decompose into a large number of spectra using optical system elements such as a prism, a diffraction grating, and a spectrum filter, the number of separated colors at the time of photometry can be greatly reduced, and the optimal exposure amount can be obtained with a small amount of photometry data. Can be determined. 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, the selection of the pixel used for determining the exposure amount is
Since the measurement is performed on the basis of the photometric data of at least three colors out of the photometric data of a large number of 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 apparatus, the handling of the film such as the switching of the transportation of the film (longitudinal feeding, horizontal feeding, etc.) and the transportation of the short film becomes easy, and the operability of the copying apparatus is improved. Furthermore, the influence 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.

According to the fourth aspect of the invention, the image recorded on the recording material is divided into a large number of pixels, each pixel is decomposed into a predetermined number of four or more colors, and photometry is performed. A pixel used for determining the exposure amount is selected based on the photometric data of at least three colors of the data, and the spectral distribution of each selected pixel is estimated based on the photometric data of the selected pixel. Further, by using the spectral distribution of each pixel and the first weighting factor obtained from the spectral sensitivity distribution of the copying material, the photometric means having the spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material for the region including the selected pixels. An average density equivalent to the average density obtained by photometry is obtained in the same manner as described above, and the exposure amount is determined.

As described above, since the spectral distribution of each pixel is estimated based on the photometric data obtained by separating each pixel into four or more colors, many optical system elements such as prisms, diffraction gratings, and spectral filters are used. It is not necessary to separate into individual spectra, the number of separated colors at the time of photometry can be greatly reduced, and the optimum exposure amount can be determined with a small amount of photometry data. Further, since the spectral distribution of the selected pixel is estimated, the calculation time can be shortened as compared with the case where the spectral distribution of all the pixels of the image is estimated.

When the photometric means is composed of two or more area sensors, it is preferable that one of the area sensors performs photometry of R, G, and B colors. Since it is necessary to accurately perform color analysis of an image in order to select a pixel, the R, G, and
It is necessary to perform alignment (registration) of the area sensor that performs B3 color photometry with high accuracy, but the photometric data obtained by photometry of other area sensors is used only for obtaining the average density. The positioning accuracy may be relatively low (even if it shifts by 1/2 pixel to 1 pixel, it is not significantly affected), and the position of the area sensor as the photometric means can be adjusted in a short time.

In the tenth aspect of the invention, the image recorded on the recording material is divided into a large number of pixels, each pixel is decomposed into a predetermined number of four or more colors, and photometry is performed. A pixel whose photometric data is used to determine the exposure amount is selected based on the photometric data of at least three colors of the data. Then, the exposure amount is determined using the photometric data of a large number of colors of the selected pixel.

For example, in the determination of the exposure amount, as described in claim 11, the spectral distribution of the region including the selected pixel is estimated by using the photometric data of the multiple colors of the selected pixel, and the estimated spectral distribution is copied. Using the spectral sensitivity distribution of the material, an average density equivalent to the average density obtained by photometry with a photometric means having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material for the region consisting of the selected pixels is calculated, and the average density is calculated as the average density. Can be determined based on. Further, as described in claim 12, the spectral distribution of each selected pixel is estimated based on the photometric data of a large number of colors of the selected pixel, and the estimated spectral distribution of each pixel and the spectral sensitivity distribution of the copying material are used. It is also possible to obtain an average density equivalent to the average density obtained by photometry with a photometric device having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material for the region consisting of the selected pixels, and to make the determination based on the average density.

Therefore, like the inventions described in claims 1 to 4, it is not necessary to decompose into a large number of spectra by using optical system elements such as a prism, a diffraction grating, and a spectral filter. Since the number of separated colors can be greatly reduced, the optimum exposure amount can be determined with a small amount of photometric data.

[0086]

【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.

On the side edge of the negative film 14, a DX code indicating the type of the negative film 14 is recorded, 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 unit 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 that has entered the area sensor 38 is applied to this filter, and is color-separated into different wavelength bands depending on the filter of the irradiated part and enters 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 so as to correspond to the substantially square block forming the filter in a one-to-one correspondence, and passes through the single L-shaped filter. The generated light is received by the three light receiving elements.

As shown in FIG. 4, light passing through one pixel of the image recorded on the negative film 14 (the size of one pixel is about 1 mm in length and width on the film) is approximately 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 sensors 34 and 36 are also composed of a filter and a two-dimensional image sensor.
Like the area sensor 38, the filter is composed of a number of three types of filters each having a central wavelength of about 430 nm, about 510 nm, about 590 nm and a half width of about 20 nm formed on one substrate. The light transmitted through the pixel can be color-separated into three types of wavelength bands for photometry. Similarly, the filter of the area sensor 36 has center wavelengths of about 630 nm, about 670 nm, and about 750 nm and a half width of about 20 each on a single substrate.
A large number of three types of filters having a wavelength of 3 nm are formed, and the light transmitted through each pixel is color-separated into three types of wavelength bands and photometry can be performed. Therefore, in the photometric unit 32, the area sensors 34, 36 and 38 decompose the incident light into pixels for each pixel 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, a program of an exposure amount control routine described below and eight principal component spectral transmittance distributions represented by transmittances with respect to wavelengths shown in FIGS. 6 to 8 (normalized with a transmittance of 100%) ) 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 main component transmittance distribution, as shown in FIGS. 16 to 18, eight main component transmission density distributions (normalized to a density of 1.0) represented by transmission densities with respect to wavelengths are used. It may be stored.

The control device 46 is connected to the photometric data memory 44 through the input / output port 48, controls the writing and reading timing of the image data memory 44, and takes in 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 section 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 area sensors 34, 36 and 38 separate the wavelength bands from each other. 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 at step 122 is affirmative, the conveyance 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. Step 126
Then, the calibration data obtained in the calibration process is fetched, the photometric data is calibrated by the calibration data, and 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.

At step 128, the photometric data memory 4
Of the photometric data stored in 4, the area sensor 3
The calibrated photometric data of three colors obtained by the photometry of No. 8 is taken into the RAM 54. ROM 52 in step 130
Value stored in advance, for example, 3 from the average mask density
Color low-density area photometric data MIN (R), MIN (G),
MIN (B) is calculated and stored in RAM. The average mask density is obtained by averaging the mask density or average minimum density of various films. A value larger than the average mask density by a predetermined value α (for example, a value of 0 to 0.6) is compared 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)> When it is (lowest density value of 3-color photometric data or average value of 3-color photometric data), it is the lowest density value of 3-color photometric data or 3
The average value of the color photometric data is used as the low density area photometric data. On the other hand, when (average mask density + α) <(lowest density value of 3-color photometric data or average value of 3-color photometric data),
A value larger by a predetermined value α than the average mask density is used as low-density portion photometric data.

At the next step 132, the low-density portion photometric data MIN (R) and MIN are obtained from each of the 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. Next step 1
At 34, the corrected photometric data R and B are converted into the density of G using the standardization curve shown in FIG. 12 and standardized (normalized) to calculate the three-color standardized photometric data.

According to this standardization, the film density and tone 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. Further, 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. 12). A standardization table is created based on

[0107] The use of standardized tables the corrected photometric data R, while B is converted to the concentration of G, as shown in FIG. 12, 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 of ₃ of the correction photometric data value B ₃ (not indicated) is also converted in the same manner an 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 or film type is 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 136, as shown in FIG. 13, the color coordinates 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.

Table 1 below 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.

[0111]

[Table 1]

In step 138, three colors corresponding to the three-color standardized data belonging to the color area A _a with _a small color difference from the reference value are selected.
Color photometric data and pixels are selected and stored in the RAM 54. When the three-color standardized data is classified by the coordinates with the color ratio as the 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. Good. In step 140, the photometric data of a large number of colors of the pixel selected above is fetched, and the average value of each color of the photometric data of the area consisting of the pixels is calculated.

Here, the number assigned to each pixel for convenience to distinguish each pixel is j, the numbers of the selected n pixels are (s ₁ , s ₂ , ..., S _n ), the wavelength λ. Assuming that the photometric data of a predetermined pixel in Eq.

[0114]

[Formula 19]

In the next step 142, the eight principal component spectral transmittance distributions are fetched from the ROM 52, and step 144
, The average density for each color calculated as described above, R
The spectral transmittance distribution T (λ) (or the spectral transmittance density distribution) of the region including the selected pixels is estimated using the main component spectral transmittance distribution acquired from the OM 52 and the spectral sensitivity distribution of each area sensor. The spectral transmittance distribution or the spectral transmission density distribution thus estimated matches the actual measurement value with high accuracy as shown in FIG. 11 as an example. FIG. 11 shows A,
It is a plot of the measured and estimated values of the spectral transmission density distribution for B, C, and D4 images.
Errors within the allowable range occur in the wavelength range around 620 nm and 720 nm, but they are almost the same in other bands.

At the next step 146, the spectral sensitivity distribution Si (λ) of the color paper 30 is fetched from the ROM 52.
In step 148, as the exposure control amount Xi, an average density equivalent to the average density obtained by photometry by the photometric section 32 having the same spectral sensitivity distribution Si (λ) of the color paper 30 is obtained. This exposure control amount Xi is calculated in step 1
Using the spectral transmittance distribution T (λ) of the image estimated in 46 and the spectral sensitivity distribution Si (λ) of the color paper 30, calculation is performed by the following equation (20).

[0117]

[Equation 20]

Here, 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 the color paper, but in the above formula (20), the first weighting coefficient for weighting the spectral transmittance distribution of the image according to the spectral sensitivity distribution of the color paper 30. Acting as a color paper 30
The average density equivalent to the average density obtained by photometry with the photometric means having the spectral sensitivity distribution that matches the spectral sensitivity distribution of, that is, the exposure control amount Xi is obtained.

When changing the type of the color paper 30, the ROM 52 is preliminarily stored in the ROM 52.
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.

In step 150, the exposure amount is determined based on the exposure control amount Xi determined in step 148.
The exposure amount is determined based on the following equation (21).

LogEi = Si · Ai (Xi−Dφi) + Ki (21) where i: any 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 152, 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, in the first embodiment, each pixel has 9 pixels.
The light is decomposed into colors, and the spectral distribution of the area consisting of the selected pixels is estimated based on the average value for each color of the photometric data of the selected pixels, so the number of separated colors is small, and the prism, diffraction grating, It is not necessary to decompose the spectrum into a large number of spectrums by using an optical system element such as a spectrum filter. Therefore, the optimum exposure amount can be determined with a small amount of photometric data. In addition, since it is not necessary to perform photometry with parallel light and it is possible to perform photometry with diffused light, the automatic printer 1
0 can be miniaturized.

Since the pixels are selected based on the photometric data of three colors of one area sensor 38 among the three area sensors for spectrophotometric measurement of nine colors, the photometric data of three colors are obtained. Since it is not necessary to separately provide a photometric means, the automatic printer 10 can be further downsized, and the handling of switching the transport of the negative film 14 (longitudinal transport, lateral transport, etc.) and transporting the piece negative becomes easy.

[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. The second embodiment has the same configuration as the first embodiment, and the operation of the second embodiment will be described below with reference to the flowchart of FIG.

Step 160 in the flowchart of FIG.
In steps 178 to 178, the same processes as steps 120 to 138 in FIG. 14 are performed. That is, the image recorded on the negative film 14 is positioned at the exposure position, the image is divided into pixels, and each pixel is separated into a large number of colors for photometry. The photometric data is stored in the photometric data memory 44 after being calibrated. Next, based on the photometric data of the three colors obtained by the photometry of the area sensor 38, the photometric data of three colors and three pixels belonging to the color region having a small color difference from the reference value are selected.

In the next step 180, the principal component spectral distribution (either the principal component spectral transmittance distribution or the principal component spectral transmission density distribution) may be fetched. In step 182, the spectral distribution Tj (λ) is estimated for each of the selected pixels.
In step 184, the spectral sensitivity distribution S of the color paper 30 is
i (λ) is taken in, and in step 186, the spectral distribution Tj (λ) obtained for each pixel and the taken color paper 3
Based on the spectral sensitivity distribution Si (λ) of 0 and 3 of each pixel.
The color density dij is calculated. When the estimated spectral distribution is the spectral transmittance distribution, the three color densities dij of each pixel can be obtained by the following equation (22).

[0127]

[Equation 21]

At the next step 188, the exposure control amount Xi
Then, the average value of the density values of the three colors of each pixel is calculated. This exposure control amount Xi is the number of the selected n pixels (s
₁ , s ₂ , ..., S _n ) are calculated by the following equation (23).

[0129]

[Equation 22]

Hereinafter, the exposure amount is calculated according to the equation (21) shown in the first embodiment, and the exposure control process is performed as in the first embodiment.

As described above, in the second embodiment, each pixel has 9 pixels.
Exposure is performed in comparison with the case where the spectral distribution of all pixels in the image is estimated because the pixels are separated based on the photometric data, the pixels are selected based on the photometric data of the three colors, and the spectral distribution of the selected pixels is estimated. The calculation time of the quantity can be shortened, and the number of separated colors is small, so there is no need to decompose into a large number of spectra using optical system elements such as prisms, diffraction gratings, and spectral filters. The optimum exposure amount can be determined by.

In the above-described embodiment, the photometric section 32 performs color-separated photometry as shown in FIG. 5, but the present invention is not limited to this. For example, as shown in FIG. The spectra split by the sensor may overlap. As shown in FIG. 15B, 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 from the maximum seven main component spectral distributions, the spectral distribution of the region including the selected pixels or the spectral distribution of each selected pixel is obtained. Will be asked.

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.

Further, in the above-described embodiment, in order to obtain the correction amounts of the three colors, the photometric data of each color obtained by dividing the light into three colors by the area sensor 38 and using the photometric data is used. It may be obtained from the weighted average value of the data.
For example, in FIG. 15A, instead of the R photometric value of 710 nm, the weighted average value of the photometric values of 670 nm, 710 nm, and 750 nm is used. 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.

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 on 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.

[0137]

According to the first aspect of the invention, the image is divided into a large number of pixels, each pixel is decomposed into a large number of predetermined colors of 4 or more, and photometry is performed. A first pixel obtained by selecting a pixel whose photometric data is used for determining the exposure amount based on the photometric data of at least three colors, calculating the average value of the photometric data of the selected pixel for each color, and calculating the spectral sensitivity distribution of the copying material. The average density equivalent to the average density obtained by photometry with a photometric means having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material in the area consisting of the selected pixels by using the weighting coefficient and the average value for each color. Since the exposure amount is determined based on the above equation, the optimum exposure amount can be determined with a small amount of photometric data, and the excellent effect that the apparatus can be downsized can be obtained.

According to the fourth aspect of the invention, the image is divided into a large number of pixels, each pixel is decomposed into a large number of predetermined colors of 4 or more, and photometry is performed. Select a pixel to use the photometric data to determine the exposure amount based on the color photometric data, and estimate the spectral distribution of each selected pixel based on the photometric data of the selected pixel,
The region formed by the pixels selected by using the spectral distribution of each pixel and the first weighting factor obtained from the spectral sensitivity distribution of the copying material is measured by the photometric means having a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copying material. Since the average density equivalent to the average density obtained by the above is determined and the exposure amount is determined, it is possible to determine the optimum exposure amount with a small amount of photometric data, and it is possible to downsize the device. The effect is obtained.

According to the tenth aspect of the invention, the image is divided into a large number of pixels, each pixel is decomposed into a plurality of predetermined colors of four or more colors, and photometry is performed. The pixel that uses the photometric data to determine the exposure amount is selected based on the color photometric data, and the exposure amount is determined using the photometric data of the multiple colors of the selected pixel. Can determine
An excellent effect that the device can be downsized can be 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 diagram showing a comparison between an estimated spectral transmission density distribution and an actually measured spectral transmission density distribution.

FIG. 12 is a diagram showing a standardization curve.

FIG. 13 is a diagram showing color coordinates for classifying three-color standardized data.

FIG. 14 is a flowchart illustrating an exposure control process of the second embodiment.

15A and 15B are diagrams showing another example of the photometric spectrum of the photometric unit.

FIG. 16 is a diagram showing first to third main component spectral transmission density distributions of a plurality of negative films.

FIG. 17 is a diagram showing fourth to sixth principal component spectral transmission density distributions of a plurality of negative films.

FIG. 18 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 (13)

[Claims] 1. A photometric means for dividing an image recorded on a recording material into a large number of pixels and dividing each pixel into a predetermined number of four or more colors to perform photometry; and a photometric means for obtaining light by the photometric means. Storage means for storing the measured light data of a large number of colors,
Pixel selecting means for selecting a pixel to be used for determining the exposure amount of the photometric data based on the photometric data of at least three colors of the multi-color photometric data stored in the storage means, and the pixel selected by the pixel selecting means. The average value of the photometric data is calculated for each color, the first weighting factor obtained from the spectral sensitivity distribution of the copying material, and the average value of the photometric data for each color are selected. An average density calculation means for obtaining an average density equivalent to the average density obtained by photometry by means of a photometric means having a spectral sensitivity distribution equal to that of the copying material for a region composed of pixels, and an exposure amount based on the average density. An exposure amount determining device for a copying machine, which comprises an exposure amount determining means for determining. 2. The average density calculating means comprises an estimating means for estimating a spectral distribution of an area consisting of the selected pixels based on an average value of photometric data of the selected pixels for each color. 2. An exposure amount determining apparatus for a copying apparatus according to claim 1, wherein the average density is calculated using a spectral distribution and the first weighting coefficient. 3. The estimating means obtains a second weighting coefficient based on an average value for each color of the photometric data of the selected pixel and a plurality of predetermined principal component spectral distributions, and the second weighting coefficient is calculated. 3. The exposure amount determination of the copying apparatus according to claim 2, wherein the spectral distribution of the region including the selected pixels is estimated by obtaining a linear sum of the plurality of main component spectral distributions using the weighting coefficient of 1. apparatus. 4. A photometric means for dividing an image recorded on a recording material into a large number of pixels and dividing each pixel into a large number of predetermined four or more colors for photometry, and a photometric means for measuring the light. Storage means for storing the measured light data of a large number of colors,
Pixel selecting means for selecting a pixel to be used for determining the exposure amount of the photometric data based on the photometric data of at least three colors of the multi-color photometric data stored in the storage means, and the pixel selected by the pixel selecting means. Using the estimating means for estimating the spectral distribution of each of the selected pixels based on the photometric data of 1. and the first weighting factor obtained from the spectral distribution of each of the estimated pixels and the spectral sensitivity distribution of the copying material. Based on the average density, an average density calculating means for obtaining an average density equivalent to the average density obtained by photometry by a photometric means having a spectral sensitivity distribution equal to that of the copying material for the region consisting of the selected pixels. Exposure amount determining means for determining the exposure amount by means of an exposure amount determining means for a copying machine. 5. The light measuring means comprises two or more area sensors for dividing the image into a large number of pieces, separating each image into two or more colors, and measuring light.
An exposure amount determining apparatus for a copying apparatus according to any one of 1. 6. At least one of the area sensors comprises:
6. The R, G, and B color photometry is performed.
An exposure amount determining device for the copying machine described. 7. The area sensor for photometry of R, G, B colors has maximum sensitivity in a wavelength band corresponding to the sensitivity wavelength bands of R, G, B colors of the copy material. The exposure amount determining device for a copying apparatus according to claim 6. 8. The selection means selects a pixel based on photometric data obtained by photometry of an area sensor that performs photometry of the R, G, and B colors.
An exposure amount determining device for the copying machine described. 9. The photometric means comprises a plurality of line sensors, and divides the image into a large number 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. 10. An image recorded on a recording material is divided into a large number of pixels, each pixel is decomposed into a large number of predetermined colors of 4 or more, and photometry is performed. An exposure amount determining method for a copying machine, which selects a pixel whose photometric data is used to determine an exposure amount based on color photometric data and determines the exposure amount by using the photometric data of a large number of colors of the selected pixel. 11. The exposure amount is estimated by using the photometric data of the plurality of colors of the selected pixel to estimate a spectral distribution of a region including the selected pixel, and the estimated spectral distribution and a spectral sensitivity distribution of a copy material are calculated. To obtain an average density equivalent to the average density obtained by photometric measurement with a photometric device having a spectral sensitivity distribution equal to that of the copying material for the area consisting of the selected pixels, and to make a determination based on the average density. 11. An exposure amount determining method for a copying apparatus according to claim 10, wherein: 12. The exposure amount is estimated by estimating the spectral distribution of each pixel selected based on the photometric data of multiple colors of the selected pixel, and using the estimated spectral distribution of each pixel and the spectral sensitivity distribution of the copying material. The average density equivalent to the average density obtained by photometry with a spectral sensitivity distribution equal to the spectral sensitivity distribution of the copy material in the area consisting of the selected pixels is calculated, and determination is made based on the average density. 11. The method for determining the exposure amount of a copying apparatus according to claim 10. 13. The exposure amount determination method for a copying apparatus according to claim 11, wherein the spectral distribution is estimated using a plurality of predetermined principal component spectral distributions.