JP2599475B2 - Exposure control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure control apparatus, and an image copying apparatus such as an automatic photographic printing apparatus for printing an image from a color original image to a copying photographic material, particularly from a color film to a color paper. The present invention relates to an exposure control device for controlling the amount of exposure.

[Conventional technology]

In general, the exposure amount when reproducing a color image from a color original image to a copying photographic material is determined by using a photometric device equipped with a color separation filter composed of a dye filter or a vapor deposition filter using red (R), green (G), The integrated transmission (or reflection) density of blue (B) light is measured, and each of R, G, and B light is determined. In order to accurately determine the amount of exposure, it is necessary to measure the amount of light that actually contributes to the exposure of the copying photosensitive material. To this end, the spectral sensitivity distribution of the photometric device must match the spectral sensitivity distribution of the copying photosensitive material. There is. The spectral sensitivity distribution of the copying photographic material is asymmetric with respect to the wavelength at which the sensitivity becomes maximum. However, in dye filters and vapor deposition filters,
It is necessary to combine many filters in order to make the transmittance distribution asymmetrical, so that it is difficult to mass-produce and to manufacture it with high accuracy.

Therefore, the photoresist exposure device decomposes the light from the original image into spectral light, and weights and adds the decomposed light to match the spectral sensitivity distribution of the photometric device with the spectral sensitivity distribution of the photosensitive material. Techniques for causing this to occur are known. JP-A-58-88624 discloses a photoresist exposure apparatus that performs the above-described processing using a diffraction grating, a converging optical system, and a photodetector. However, spectral sensitivity characteristics are reduced due to the mutual arrangement of these optical elements. Complex meganism is needed to keep it from changing. JP
Japanese Patent Application Laid-Open No. 61-95525 discloses a photoresist exposure apparatus in which a number of interference filters are arranged instead of the diffraction grating. However, since a large number of interference filters are required, it is difficult to mass-produce when the number of exposure wavelengths is large. In addition, since the light is divided into a large number of spectra, the width of one spectrum is narrowed and the amount of light is reduced. However, there is a problem that the sensitivity becomes insufficient. In a color photographic printer, Japanese Patent Application Laid-Open No. 1-134353 discloses that a light from an original image is spectrally decomposed using a prism, a diffraction grating, or a spectral filter, and a part of a copy document is slit into a photoelectric sensor panel. A technique for forming an image is disclosed. In this technique, different photometric positions are represented in rows of a panel, and spectrum light corresponding to the photometric position is converted into an electric signal in an example of a panel. This technique has the same problem as described above because it uses a diffraction grating and a spectral filter.
Also, since the light is split by refraction using a prism, it is necessary to make the projection light parallel, the size of the device increases, and the amount of light is greatly reduced due to the decomposition of rows into columns. There is a drawback that a large light quantity difference occurs in the spectrum and that photometry cannot be performed on the same panel. Japanese Patent Application Laid-Open No. 1-142719 discloses that a prism or a diffraction grating, a lens, and a two-dimensional array sensor are used. However, since a prism or a diffraction grating is used, there is a similar problem as described above.

The present invention has been made in order to solve the above-mentioned problems, and provides a photometric means that matches a spectral sensitivity distribution with high precision to a copying photosensitive material without using a special filter or a prism for dispersing a large number of spectral lights. It is an object of the present invention to provide an exposure control apparatus that can be provided and that can be mass-produced at a small size and at low cost.

As a technique related to the present invention, a filter composed of a multilayer thin film is combined with an exposure optical system of a copying machine,
A technique for relatively lowering the sensitivity of a photoreceptor by changing the angle of a filter with respect to incident light (JP-A-55-6365), an optical system for projecting a document image on the photoreceptor surface in an electrophotographic copying apparatus (Japanese Patent Application Laid-Open No. 56-57060), in which an interference transmission filter is rotatably provided in the optical path of the device, and the exposure amount is changed by changing the incident angle of the image forming light to the interference transmission filter. In order to prevent the effect of the lamp heat from shifting to the longer wavelength side and affecting the red-sensitive layer of the color paper, the long wavelength cut filter is tilted with respect to the incident light to reduce the characteristics to the shorter wavelength side. (Japanese Patent Application Laid-Open No. 61-281230).

[Means for solving the problem]

In order to achieve the above object, the present invention provides an interference filter for decomposing light for original image photometry into red light, green light, and blue light, and an angle formed between the interference filter and light incident on the interference filter,
The light transmitted through the interference filter has an angle that is split into a plurality of decomposed lights in a wavelength band corresponding to each of the red light sensitive wavelength band, the green light sensitive wavelength band, and the blue light sensitive wavelength band of the copying photosensitive material. Changing means to change, each transmitted light of the interference filter of each state changed so that the angle becomes each angle by the changing means, photometry after transmitting the original image,
Alternatively, the light transmitted through the original image is transmitted through the interference filter in each state in which the angle is changed by the changing unit to each of the angles. A sensor that measures light, green light, and blue light, and calculates a combined value based on the photometric value of the photometric means, which is equivalent to that measured by the photometric means having the same or similar spectral sensitivity distribution as the spectral sensitivity distribution of the copying photosensitive material to be copied. Computing means for performing
The basic exposure amount is determined based on the combined value calculated by the calculating means, or based on the color control value determined based on the combined value calculated by the calculating means and the density control value determined based on the photometric value of the sensor. Control means for determining a basic exposure amount and controlling the exposure amount based on the basic exposure amount.

The photosensitive filter can be configured by arranging a plurality of portions that decompose into red light, a portion that decomposes into green light, and a portion that decomposes into blue light in a stripe shape or a mosaic shape.

[Operation] The interference filter of the present invention converts the light for the original image photometry into red (R) light.
Decomposes into light, green (G) light and blue (B) light. As described above, the interference filter can be configured by depositing each of the interference film that decomposes into R light, the interference film that decomposes into G light, and the interference film that decomposes into B light on one substrate. An interference film for R light, an interference filter for G light, and an interference filter for B light may be separately formed by depositing interference films on different substrates. Also, a portion that decomposes into R light,
The interference filter may be configured by arranging a plurality of portions that decompose into G light and a plurality of portions that decompose into B light in a striped or mosaic shape. In this case, an image sensor such as a CCD having a large number of photometric elements is used as photometric means. By using the interference filter and the image sensor, it is possible to obtain the average screen density of the original image.

The photometric means measures the light transmitted through the interference filter in a state where the interference filter and the light incident on the interference filter form a predetermined angle, thereby providing a red light sensitive wavelength band, a green light sensitive wavelength band, and The wavelength band corresponding to each of the blue light sensitive wavelength bands is divided into a plurality of separated lights to measure the original image.
It is known that the center wavelength of the spectral transmittance distribution of the interference filter shifts to the shorter wavelength side as the angle of incidence on the interference filter increases, and that the interference filter and the light incident on the interference filter have a predetermined angle. By metering the light transmitted through the interference filter in the formed state, the original image can be metered by separating the light into the target center wavelength decomposed light.
In this case, the optical path of the interference filter and the incident light may be fixed so that the interference filter and the incident light on the interference filter form a predetermined angle, but the interference filter and the light incident on the interference filter may be fixed. A change means for changing the angle is provided,
The incident angle may be changed continuously or stepwise from, for example, 0 ° to 45 °, and the light may be measured by splitting the light into the target central wavelength decomposed light. To change the angle between the interference filter and the light incident on the interference filter, the interference filter may be rotatably disposed and rotated by a step motor or the like. Alternatively, the angle may be changed by disposing a rotatable mirror on the incident side of the interference filter and rotating the mirror to change the optical path of the incident light.

The spectral sensitivity distribution of copying photographic materials, especially photographic color paper, is similar in the shape of the light sensitivity distribution regardless of the manufacturer, type, etc., and the R, G and B light of the spectral sensitivity of various color papers. The maximum value of the light exists in substantially the same wavelength band. Therefore, if the wavelength bands corresponding to the R light, the G light, and the B light, preferably the wavelength band corresponding to the maximum sensitivity wavelength band, are spectrally separated into at least two or more, preferably three or more, decomposed light beams, and photometry is performed. Various copying materials based on photometric values,
In particular, it is possible to easily obtain a combined value equal to that measured by photometric means having the same or similar spectral sensitivity distribution as that of various color papers. For this reason, the calculating means calculates a combined value equal to that measured by a sensor having the same or similar spectral sensitivity distribution as the spectral sensitivity distribution of the copying photosensitive material based on the photometric value of the photometric means.

Thus, the basic exposure amount is determined based on the composite value obtained by the calculation means, and the exposure amount can be controlled with the basic exposure amount.

In the present invention, a sensor is provided for measuring the R, G, and B light by dividing the original image into a large number. The photometric unit is capable of determining the color control value based on the combined value obtained by the arithmetic unit, since the photometric unit performs the photometry by splitting the light into a plurality of separated lights. The spectral sensitivity distribution of the sensor does not always exactly match the spectral sensitivity distribution of the copying photographic material. For this reason, the basic exposure amount may be determined based on the color control value determined based on the composite value obtained from the photometric value of the photometric unit and the density control value determined based on the measured value of the sensor.

Further, since the sensor is further provided with a sensor that divides the original image into a large number and measures the light, a predetermined calculation is performed based on the image feature amount obtained from the measurement value of this sensor (see Japanese Patent Application Laid-Open No.
-28131, JP-A-55-38410 and JP-A-61-3133 can be used. ) Select the required photometric value
-189457, JP-A-61-18144, and JP-A-63-312441 can be used. ), A correction value corresponding to the image content of the original image may be determined, and the basic exposure amount may be corrected with the correction value.

The maximum spectral sensitivity of various color papers is 460 to 4
It exists in the wavelength band of 85 nm, the wavelength band of 540 to 560 nm, and the wavelength band of 680 to 710 nm, that is, the wavelength bands of the three primary colors, so that the angle formed between the interference filter and the light incident on the interference filter is adjusted and the photometric means is used. It is preferable that each of these wavelength bands is divided into a plurality of decomposed lights for photometry.

〔The invention's effect〕

As described above, according to the present invention, the red light-sensitive wavelength band, the green light-sensitive wavelength band, and the blue light-sensitive wavelength band of the copying photosensitive material are determined by determining the angle formed between the interference filter and the light incident on the interference filter. A special filter that splits the spectrum into a large number of spectral lights to match the spectral sensitivity distribution of the photometric means to the spectral sensitivity distribution of the copying photosensitive material because the wavelength band corresponding to This eliminates the need for a prism and the like, and provides an effect that a small-sized, low-cost exposure control device that can be easily mass-produced can be provided. In addition, when the film screen is divided into a plurality of pieces and the photometry is performed, the photometry can be easily performed by splitting the photo into a plurality of decomposed lights.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, the present invention is applied to a color photographic printer in which an exposure optical system and a photometric optical system are present at different positions. As shown in FIG. 1, a lamp house 10 having a mirror box 18 and a halogen lamp is disposed below a negative film 20 loaded in a negative carrier and transported to an exposure unit. A light control filter 60 is disposed between the mirror box 18 and the lap house 10.
As is well known, the light control filter 60 is composed of three color filters of a Y (yellow) filter, an M (magenta) filter, and a C (cyan) filter.

Above the negative film 20, a lens 22, a black shutter 24 and a color paper 26 are arranged in order,
Light emitted from the lamp house 10 and transmitted through the light control filter 60, the mirror box 18, and the negative film 20 is formed on a color paper 26 by a lens 22 to expose the color paper.

A photometric optical system is arranged upstream of the above-described exposure optical system. Like the exposure optical system, a mirror box 18 is provided below the negative film 20 transported to the photometric section of the photometric optical system.
And a lamp house 10 equipped with a halogen lamp. Between the mirror box 18 and the lamp house 10, a filter (interference filter) 30 fixed to the rotation shaft 31 of the step motor 32 and rotatable is arranged. As shown in FIG. 2, the filter 30 is composed of a B filter 30B that transmits B light, a G filter 30G that transmits G light, and an R filter 30R that transmits R light. Such a filter 30 has a B
It can be manufactured by sequentially depositing an interference film for a filter, an interference film for a G filter, and an interference film for an R filter.

The spectral sensitivity distribution of the color paper is such that the long wavelength side is sharply cut and the short wavelength side is gently distributed. The shift amount of the center wavelength of the spectral transmittance distribution when the angle of incidence on the filter is gradually increased from 0 ° is:
And the half width tends to increase. Therefore,
Using a filter in which the center wavelength of the spectral transmittance distribution at the incident angle 0 ° matches the wavelength corresponding to the maximum sensitivity of the color paper, and increasing the incident angle gradually from 0 ° as described above, Photometry can be performed without reducing accuracy on the short wavelength side where the sensitivity distribution is gentle. Also, increasing the incident angle increases the amount of light reflected from the surface of the filter and lowers the spectral transmittance. Therefore, when the incident angle is large, half of the decomposed light with respect to the required center wavelength is synthesized by combining decomposed light. The value range may be widened to compensate for the lack of light.

Hereinafter, a specific example of the center wavelength of the spectral transmittance distribution of the filter will be described. FIG. 3 shows the G filter 30 of the filter 30.
FIG. 9 shows a change in a spectral transmittance distribution with respect to an incident angle of light to a G portion. When the plane of the G filter 30G is perpendicular to the incident light, that is, when the incident angle of the light is 0 °, the central wavelength of the spectral transmittance distribution is 555 nm. When the incident angle becomes 15 °, the central wavelength of the spectral transmittance distribution shifts to 547 nm on the short wavelength side, and when the incident angle becomes 30 °, the central wavelength of the spectral transmittance distribution further shifts to 533 nm on the short wavelength side, and the incident angle increases. Becomes 45 °, the center wavelength of the spectral transmittance distribution becomes 512n on the shorter wavelength side.
Shift to m. Since the G light maximum sensitivity wavelength band of the color paper exists in the wavelength band of 540 to 560 nm, by changing the incident angle as described above, the wavelength band corresponding to the G light maximum sensitivity wavelength band of the color paper becomes the center wavelength. , 547 nm and 555 nm can be measured by spectroscopy. Center wavelength 533n
The photometric value corresponding to the sensitivity on the short wavelength side of the spectral sensitivity distribution of the G layer of the color paper can be obtained from the resolved light of m and 512 nm.

For the B filter 30B, the incident angle of the incident light is set to 0.
From ゜ to 460 to 485 corresponding to the maximum sensitivity wavelength band of B light of color paper by changing it so that it gradually increases.
For example, if the center wavelength of the spectral transmittance distribution is 480 ± 5
It splits into three decomposed lights of nm, 470 ± 5 nm and 460 ± 5 nm. Further, the R filter 30R portion corresponds to, for example, the R light maximum sensitivity wavelength band of color paper by changing the incident angle of the incident light so as to gradually increase from 0 °.
The center wavelength of the spectral transmittance distribution is 710 to 680 to 710 nm.
The light is split into three separated light beams of ± 5 nm, 700 ± 5 nm, and 690 ± 5 nm. Similarly to the G filter 30G portion, the R filter 30R portion can obtain resolved light having a wide half width with a center wavelength of 660 ± 5 nm and 630 m ± 5 nm on the short wavelength side.

Above the negative film 20, die mirrors 50 and 52 for separating the R, G, and B separated lights that have been color-separated by the filter 30 and transmitted through the mirror box 18 and the negative film 20 to the B, G, and R light sensors. Is arranged. A line sensor that measures B light on the reflection side of the Die-Roytsk mirror 50
68 are located. A line sensor 66 for measuring R light is disposed on the reflection side of the die-shaped mirror 52, and a line sensor for measuring G light on the transmission side of the die-shaped mirror 52.
64 are located. These line sensors 64, 66, 68
Is composed of CCD, etc., CPU (central processing unit), RAM (random access memory), ROM (read only memory)
Are connected to an exposure control circuit 36 composed of a microcomputer having Hereinafter, line sensors 64 and 6
6 and 68 are collectively referred to as a first sensor. Each of the first sensors may be constituted by an area sensor. A position in which the image density of the negative film 20 can be measured in a direction inclined with respect to the optical axis of the photometric optical system is constituted by a three-color separation filter and a two-dimensional image sensor. And a second sensor 34 for measuring the R, G, and B light by disassembling the light. Here, the R light is 600 to 750 nm,
G light can be employed within a range of 500 to 600 nm, and B light can be employed within a range of 400 to 500 nm.

The second sensor 34 is connected to the control circuit 36. The control circuit 36 is connected to the stepping motor 32 so as to control the angle of the surface of the filter 30 with respect to the light emitted from the lamp house 10, and is connected to the dimming filter 60 so as to control the amount of printing. I have.

In the above description, one filter is used for each of the B filter, the G filter, and the R filter. However, a filter may be configured using a plurality of each of the B filter, the G filter, and the R filter. FIGS. 4 and 5 show examples of filters configured in this manner. FIG. 4 shows an example in which B filters 30B, G filters 30G and R filters 30R are arranged in a stripe pattern. FIG. This shows an example in which a G filter and an R filter 30R are arranged in a mosaic pattern.

Next, with reference to FIGS. 6 (1) to 6 (3), the principle of calculating the composite value used for controlling the exposure amount will be described. As shown in FIG. 6 (1), by changing the incident angle to the above-described filter, the maximum sensitivity wavelength band is divided into three separated lights, and the spectral sensitivity distribution is as shown in FIG. 6 (2). It is assumed that a spectral characteristic curve from an actual measurement value when an original image is measured by using the sensor having the following formula is represented by f ₁ (λ), and a true spectral characteristic curve is represented by f ₂ (λ). In the present invention, the spectral characteristics of the original image mean a spectral transmittance distribution, a spectral reflectance distribution, a spectral density distribution, a spectral reflection density distribution, or characteristics and values corresponding thereto. Note that S in FIG. 6 (2)
_{λ 1} , S _{λ 2} , S _{λ 3} indicate the respective spectral sensitivity distributions of the sensors S ₁ , S ₂ , S ₃ . The spectral sensitivity distribution of the three sensors _{S λ 1, S λ 2,} S λ 3 by that it has a distribution, the photometric value of the film dyes have different values and the true values. Since the spectral characteristics of the original image (that is, the film dye) have a gentle distribution shape, it can be estimated with a small number of wavelengths. Therefore, λ ₁ is an intermediate wavelength between the central wavelengths of S _{λ 1} and S _{λ 2} , λ ₂ is an intermediate wavelength between the central wavelengths of S _{λ 2} and S _{λ 3} , and λ ₀ is a central wavelength of S _{λ 1} which is λ ₀ . as will be lambda ₁ of the intermediate, lambda ₃ and the _second center wavelength of S _{lambda 3} is lambda lambda
₃ is set so that λ ₀ <λ ₁ <λ ₂ <λ ₃ , and the spectral sensitivity distribution of each sensor is reduced to a small section [λ ₀ , λ
₁ ], [λ ₁ , λ ₂ ] and [λ ₂ , λ ₃ ]. For example, the spectral characteristics a and b of the original image of [λ ₀ , λ ₁ ] are approximated by cd. The true values at the center wavelength in each small section are T ₁ , T ₂ , T ₃ , the measured values are F ₁ , F ₂ , F ₃ , and the spectral sensitivity distributions of the sensors are S _{λ 1} , S _{λ 2} , S _{λ 3} And The spectral sensitivity distribution of the copying photosensitive material is represented by FIG. 6 (3), and the spectral sensitivity of the copying photosensitive material at the center wavelength point of each sensor is P ₁ ,
And P _2, P _3. When the actual measurement value F ₂ of the small section [λ ₁ , λ ₂ ] is represented using the true value and the spectral sensitivity distribution of each area of the sensor, the following equation is obtained.

Note that the measured values F ₁ and F ₃ can be obtained in the same manner as described above.

 The above equation (1) is generally expressed as follows.

Here, j is a number assigned according to the wavelength and j =
1, 2, 3,... N, where i is a number assigned to the peak value of the spectral sensitivity distribution of the sensor, that is, a number assigned to each region of the sensor, and in the above case, i = 1,
Two, three.

If the sensor area is further generalized so that the number of sensor regions is n and the light is separated into n pieces of light to be measured, the following equation is obtained.

The spectral sensitivity distribution of the sensor Sadamari spectral sensitivity S _{lambda i} in the arbitrary section [j-1, j] if is previously determined, the equation (3) Is a predetermined value (eigenvalue) unique to the sensor. When the relationship between the true value, the measured value, and the eigenvalue is represented by a matrix with this eigenvalue as Sij, the following is obtained.

F = T · S (4) where It is.

Therefore, when the inverse matrix of S is represented by S ⁻¹ , the true value T is S ^−1.
Represented by F.

The photometric value when measured with a sensor having the same spectral sensitivity distribution as the photosensitivity distribution of the copy photosensitive material, that is, the composite value Tp,
It is expressed as follows.

Here, K = ΣΔPi / n, ΔPi is an arbitrary section [j−1,
j] is the wavelength width λj−λj− ₁ . Therefore, the second
In the case of the filter and the sensor shown in the figure, the spectral sensitivity distributions S _{λ 1} , S _{λ 2,} ... The values S ₁₁ , S ₂₁ , S ₃₁ … unique to the sensor and the spectral sensitivities P ₁ , P ₂ , P ₃ … of the photosensitive material or values corresponding thereto are stored in the ROM of the control circuit 36 and are unique to the sensor. After calculating the spectral distribution of the film dye, that is, the image frame to be printed, as an appropriate value, and performing the calculation of the above equation (6), the composite value
Tp can be determined. The spectral sensitivity distribution of each sensor may be stored in place of the value specific to the sensor, and the spectral sensitivity distribution itself may be stored in place of the spectral sensitivity of the copying photosensitive material. Also, the values S ₁₁ , S ₂₁ ,... Unique to the sensor and the spectral sensitivities P ₁ , P _{2 of the} copying photosensitive material
.. Or a weighting coefficient multiplied by a value corresponding thereto.

FIG. 7 shows an exposure amount calculation routine of the control circuit 36. The photometric optical system stops the negative film 20 and drives the step motor 32 at a predetermined number of steps at step 92 to adjust the angle of the filter 30. I do. Next Step 94
Then, photometry is performed by the line sensor, and the photometry value is stored in the RAM of the control circuit 36 in step 96. In the next step 98, it is determined whether the photometry has been performed for each of the R, G, and B lights, that is, whether the photometry has been performed for all of the wavelength bands corresponding to the maximum sensitivity wavelength band of the color paper. The photometry is repeated as described above. As a result, for the G filter, the incident angles are 0 °, 15 °, 30 °,
The angle of the filter is adjusted to be 45 °, and the photometric value of the line sensor at each angle is stored in the RAM. B, R
Also for the filter, the photometric value is obtained by adjusting the angle of the filter so that the above-described resolved light of the center wavelength is enhanced. In the next step 100, the photometric value Fi stored in the RAM is fetched, and in step 102, the unique value Sij stored in the ROM is read. In the next step 104,
As described above, the true value Ti is predicted using the photometric value Fi and the eigenvalue Sij. In the next step 106, the spectral sensitivity Pi of the copy photosensitive material is read from the ROM, and in step 108, the composite value Tp is calculated based on the above equation (6). In step 110, the basic exposure amount Dp is calculated in accordance with the following equation, where the combined value Tp is Tr, Tg, Tb, and the screen average photometric value of the second sensor is mr, mg, mb. Here, r, g, and b represent red, green, and blue, and p is any one of r, g, and b.

Dp = (mr + mg + mb) / 3 + Tp- (Tr + Tg + Tb) / 3 (7) Equation (7) performs color control by the first sensor and density control by the second sensor, and the three colors of the second sensor are used. The difference between the colors of the first sensor is added to the average density. The correction value of the basic exposure amount by the second sensor is the second exposure value.
The correction value of the density for the three-color average density of the sensor and the color correction value of mr, mg, and mb of the second sensor may be obtained and added to the basic exposure amount Dp. It goes without saying that the spectral sensitivity distribution of the second sensor should be closer to the copying photographic material in order to increase the accuracy of these calculations.

The basic exposure amount Dp may be calculated according to the following equations (8), (9), (10), and the like.

Dp = (mr + mg + mb) / 3 + (Tp−Tg) (8) Dp = mg + (Tp−Tg) (9) Dp = Tp (10) The control circuit 36 converts the negative film into an exposure optical system. The light is conveyed, and the exposure is controlled by controlling the light control filter 60 according to the basic exposure Dp.

In order to correct the density, color area, and the like based on the shooting scene, a correction amount is calculated based on the photometry value of the second sensor, and a value obtained by adding the correction value to the basic exposure amount is used for exposure control. The exposure amount is controlled as a value. The method of calculating the correction amount and the method of controlling the exposure amount are described in JP-A-63-311241,
It is described in detail in, for example, JP-A-63-312442.

As described above, according to this embodiment,
As described in No. 1241, film types having different film characteristics can be printed under the same printing conditions, and prints of higher quality than before can be made from various types of films. The effect is obtained. If applied to a color copier, original images with different spectral sensitivity distributions (photo originals, print originals,
Illustrations, perspective solid objects, etc.) can be copied under the same copy conditions.

In the above embodiment, the basic exposure amount Dp is shown as in equations (7) to (10). However, the image feature amount (for example, the maximum density, the minimum density, the partial area density) obtained from the photometric value of the second sensor is used. ) May be used as the basic exposure amount. A correction formula (or conversion table) for the photometric value of the second sensor is created from the correspondence between the photometric values of the first and second sensors, and the photometric value of the second sensor is converted to the photometric value of the first sensor. The exposure value may be converted to an approximated value, the exposure amount may be obtained based on the converted value, and exposure control may be performed. Further, the exposure amount obtained by the second sensor may be corrected by the photometric value obtained by the first sensor. In this case, the difference between the basic exposure amounts obtained from the photometric values of the first and second sensors may be used as the correction value. Further, the example in which the eigenvalue is stored has been described. However, the eigenvalue may be obtained by calculation by storing the spectral sensitivity distribution of each region of the sensor.

Further, in the above description, an example in which the spectral sensitivity distribution of the original image is estimated from the photometric value and the eigenvalue obtained from the spectral sensitivity distribution of the sensor has been described, but the weight added to the photometric value is estimated without estimating the spectral distribution. Is also good. That is, as shown in FIGS. 8 (1) and (2), the spectral sensitivity distributions of the sensors S ₁ , S ₂ , S ₃ are added to S _{λ 1} , S _{λ 2} , S _{λ 3} and the spectral sensitivity distributions. Are W ₁ , W ₂ , and W _3, and the spectral sensitivities of the copy photosensitive material are M ₁ , M ₂ , and M ₃ . Spectral sensitivity distribution of copy photosensitive material is a sensor
_They can be matched by weighted addition of the spectral sensitivity distributions of S ₁ , S ₂ , and S ₃ . Since these can be expressed as M = WS when expressed by a matrix, the weights are expressed as follows.

W = S ^-1 · M (11) Therefore, if the spectral sensitivity distribution of each area of the sensor and the spectral sensitivity distribution of the copy photosensitive material are stored in the ROM and the calculation of the above equation (11) is performed, the sensor From the photometric value, a weight W for estimating a photometric value equal to that measured by a sensor having the same or similar spectral sensitivity distribution as the spectral sensitivity distribution of the copying photosensitive material can be obtained. Then, if the photometric value of the first sensor is multiplied by the weight and integrated with respect to the wavelength, the composite value Tp can be obtained.

Further, in the above description, the printing apparatus in which the photometric optical system and the exposure optical system are located at different portions has been described. However, a printing apparatus in which the photometric optical system and the exposure optical system are arranged at the same location may be used.

FIG. 9 shows a B filter on the light reflecting side of the rotating mirror 40.
30B, a G filter 30G, and an R filter 30R are arranged, and a line sensor 68 is arranged on the transmission bundle of each filter, and a plurality of integrated ones are arranged at shifted positions. An area sensor may be used instead of the line sensor.

FIG. 10 shows the case where the G filter 30G and the line sensor 64 are integrally rotated to adjust the angle of incidence on the G filter 30G. The B and R filters are configured similarly to the G filter. Also, the R, G, and B filters are integrally arranged in the moving direction of the film, and slit light is applied at right angles to the moving direction of the film. The slit light transmitted through the film is condensed by a lens and transmitted to the sensor. . Each filter may be rotated at right angles to the arrangement direction in a state where light is irradiated to each filter. By projecting the slit light transmitted through the film onto the line sensor, and moving the film while rotating in the slit direction, R, G,
The film screen can be scanned with a plurality of decomposition lights for each of B.

FIG. 11 shows an arrangement in which a mirror 80, a half mirror 82, and a total reflection mirror 84 having a transmittance of approximately 67% are arranged in order so that the angle with respect to the optical path is 45 °, and the incident angle is predetermined on the reflection side of each mirror. The G filters G ₁ , G ₂ , G ₃ are arranged so as to form an angle. The incident angles of the G filters G ₁ , G ₂ , G ₃ are, for example, 0 °, 10 °, and 15 °. Also, each filter G ₁ ,
Line sensors 64A, 64B, 64C on the light transmission side of G ₂ and G ₃
Is arranged. The B and R filters have the same configuration as described above. The B and R filters can be divided into three parts and arranged adjacent to the G filters G ₁ , G ₂ and G ₃ .

FIG. 12 shows the translucent mirrors 80, 82, and 84 described in FIG.
Are arranged at different angles with respect to the optical path so that the incident angle with respect to the G filter 30G is, for example, 0 °, 10 °, 1 °.
5 ゜. The B and R filters are similarly configured. 11 and 12, the filter or mirror is rotated to irradiate the film with the slit light, and the negative is driven, so that the original image of the filter can be divided into a large number of pieces to perform photometry. In the case where the original film is scanned with a large number of light components, the first sensor and the second sensor are used.
And the second sensor is unnecessary.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a color photographic printer to which the present invention can be applied, FIG. 2 is a plan view showing a filter used in this embodiment, and FIG. 3 is a view of the filter shown in FIG. FIG. 4 is a diagram showing a spectral transmittance distribution of a G filter portion, and FIG.
FIG. 5, FIG. 5 is a plan view showing another example of the filter used in the present embodiment, FIGS. 6 (1) to (3) are diagrams for explaining the operation principle of the composite value, and FIG. FIG. 8 is a flow chart showing a calculation routine of the above embodiment, FIG. 8 is a diagram for explaining another example of calculating a composite value, and FIGS. 9 to 12 change incident angles to the first sensor and the filter. FIG. 9 is a schematic diagram showing another example of the changing means to be changed. 30 ... Filter, 34 ... Second sensor, 64, 66, 68 ... Sensor.

Claims (2)

(57) [Claims] 1. An interference filter for decomposing light for photometry of an original image into red light, green light, and blue light; an angle formed between the interference filter and light incident on the interference filter; Red light sensitive wavelength band, green light photosensitive wavelength band and changing means for changing so as to be each angle to be separated into a plurality of decomposed light of the wavelength band corresponding to each of the blue light sensitive wavelength band, the changing means, The transmitted light of the interference filter in each state in which the angle has been changed to each of the angles, the light transmitted through the original image is measured, or the light transmitted through the original image, the angle is changed by the changing unit so that each of the angles , A photometer that measures the light after passing through the interference filter in each state that has been changed so as to have an angle, a sensor that divides the original image into many pieces, and measures red, green, and blue light, and a photometric value of the photometer. Copy based on Calculating means for calculating a composite value equivalent to that measured by the photometric means having the same or similar spectral sensitivity distribution as that of the copying photosensitive material to be copied; and determining the basic exposure amount based on the composite value calculated by the calculating means. Or a basic exposure amount is determined based on the color control value determined based on the composite value calculated by the calculating means and the density control value determined based on the photometric value of the sensor, and the exposure amount is determined based on the basic exposure amount. An exposure control device, comprising: control means for controlling; 2. The interference filter according to claim 1, wherein the interference filter is configured by arranging a plurality of portions that decompose into red light, a portion that decomposes into green light, and a portion that decomposes into blue light in a stripe shape or a mosaic shape. Exposure control device.