JPH0572573B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention provides a method for transmitting image information of an original film such as a negative film used in a photographic printer without inserting a beam splitter and through a printing or printing imaging lens. The present invention relates to a photographic printing device that detects an original image by directly viewing it and dividing it into a large number of pixels.

(Technical background of the invention and its problems) In a photo printing apparatus, the density of the original film (for example, negative film) must be measured in order to determine the printing exposure amount or correction amount. An optical sensor such as a photodiode placed nearby measures the average density of the negative film using LATD (Large Area Transmittance).
I am trying to measure the light using Density). this
LATD is the average photometry of a negative film, and it is well known that exposure determined only by LATD causes sub-effect area. In order to prevent this, a person manually performs visual judgment and additionally inputs the exposure correction amount before printing. In addition, in order to automatically correct the image, the image density is determined by dividing the entire film screen into multiple photometers, determining the exposure correction amount for the printing exposure amount based on LATD, and controlling the exposure using both. It is also well known.

Conventionally, scanners configured to scan the screen of negative film using photodiodes, photomultiplier tubes, etc. are often used, but these have drawbacks such as being expensive, large, and having operational restrictions. It was hot. An example of such a device is to divide the negative film screen into left, right, top, and bottom sections and measure the light.
A method has been proposed in which the printing exposure amount is determined and then corrected (for example, Japanese Patent Publication No. 56-2691). Furthermore, since the optical path is branched using a half mirror, the structure becomes complicated and the detection accuracy deteriorates. Tokuko No. 42-25220 and Tokukai Sho
The same applies to No. 59-101643.

The latter device has an imaging function for LATD photometry and display on a monitor television, and uses a prism or mirror for imaging. It was also considered to configure the photodetector with a charge transfer device such as a CCD and perform scanning electrically, but the accumulation type photodetector has a narrow dynamic range, and the amount of exposure is determined by metering the photo film. There was a problem that I couldn't use it.

(Object of the Invention) This invention was made in view of the above-mentioned circumstances, and it is an extremely simple photometric device configured to accurately detect image information on an original film by dividing it into a large number of pieces, thereby automatically detecting the image information. It is an object of the present invention to provide a photo printing device that can print photos with high accuracy.

(Summary of the Invention) This invention relates to a photographic printing device.
The transmitted light of the negative film illuminated by the printing light source is separated into red, green, and blue, and the average photometry of the frame images to be printed on the negative film is calculated, and the LATD is determined and each of the red, green, and blue printing exposures are performed. an optical sensor for determining the amount of light; a two-dimensional area sensor that sets a value of a snaking part of image information obtained from a photometric signal of a film image to 0 or around it, and then measures the image density of the frame image; The exposure correction amount is determined based on the measured image density, and the printing is performed by correcting each of the printing exposure amounts.

(Embodiment of the Invention) FIG. 1 shows an example in which the present invention is applied to a conventional photoprinting apparatus, in which a charge accumulation type two-dimensional image sensor 10 such as a CCD as an image information detection device is used as a conventional general photoprinting apparatus. The photo printing apparatus is provided so that the negative film 2 can be photometered without inserting a beam splitter such as a half mirror and without using a printing imaging lens. The two-dimensional image sensor 10 electrically scans the image of the negative film 2 from a position off the exposure optical axis from the negative film 2 to the photographic printing paper 7, divides it into a large number of pixels, and measures the measured data. Based on this, the exposure correction amount for the exposure amount determined by the LATD measured by the photometer 8 is determined, and photographic printing is performed. A photometric device including a two-dimensional image sensor performs photometry without using a beam splitter, so it can be easily installed in conventional devices and has a small and simple photometric configuration. In other words, the negative film 2 sent to the negative carrier 1 position is yellow 4 (Y) and magenta (M).
The negative film 2 is illuminated by a light source 4 through three primary color filters 3 of 3 and cyan (C), and the transmitted light from the negative film 2 passes through a lens system 5 and a black shutter 6 to reach photographic paper 7. . The photographic paper 7 is wound around a feed roller 7A, and is wound around a roller 7B in synchronization with the conveyance and stopping of the negative film 2. An optical sensor 8 such as a photodiode is arranged near the lens system 4 side of the negative film 2 to detect image density information of the three primary colors of red (R), green (G), and blue (B). The exposure amount is determined based on the detection signal (LATD) of this optical sensor 8, and photographic printing is performed.
LATD simply measures the transmitted light that passes through the negative film and converts it to density, and is the average density that includes image density and base density. The exposure amount determined by LATD generates a sub-effect area, and conventionally, the exposure amount has been corrected by determining the exposure correction amount by visual inspection or by using a scanner. The two-dimensional image sensor 10 is tilted to the optical axis LS between the light source 4 and the negative film 2.
In front of the two-dimensional image sensor 10, a lens system 11 for forming an image approximately at the center of the negative film 2 is disposed near the two-dimensional image sensor 10, and is integrated into a unit. A substrate 12 is attached to the back side of the detection device, on which a processing circuit made of an IC or the like for image processing is mounted.

Here, the two-dimensional image sensor 10 includes an imaging unit 101 that optically captures an image, as shown in FIG.
, an accumulation section 102 for accumulating the charges transferred from the imaging section 101, and an output register section 10 for outputting the charges accumulated in the accumulation section 102.
3, photoelectrically converts two-dimensional (area) image information by controlling drive signals 101S to 103S from the drive circuit, and serially outputs an analog image signal PS from the output register unit 103. It is now output to . In addition, the substrate 12
The circuit configuration installed in the image sensor 10 is, for example, as shown in FIG.
are drive signals 101S to 103 from the drive circuit 20
The light driven by S and irradiated onto the imaging unit 101 of the image sensor 10 is output to the output register unit
is output as an image signal PS, sampled and held in the sample hold circuit 21 at a predetermined sampling period, and the sample value is
The AD converter 22 converts it into a digital signal DS. The digital signal DS from the AD converter 22 is inputted to a logarithmic conversion circuit 23 where it is logarithmically converted, converted into a density signal DN, and then written into the memory 25 via the write control circuit 24. Note that the write control circuit 24 receives a read speed signal RS from the drive circuit 20 for driving the image sensor 10 and reading image information at a constant speed,
The density signals DN are sequentially written to predetermined positions in the memory 25 according to the driving speed of 0.

In such a configuration, when performing normal photographic printing, the optical sensor 8 detects the transmitted light of the negative film 2 that has been conveyed and is stationary in the printing section, and the LATD for each of the three primary colors, RGB, is used to detect the transmitted light. The filter 3 is adjusted according to the determined exposure amount, the black shutter 6 is opened, and the photographic paper 7 is exposed to the determined exposure amount.

In this invention, a two-dimensional image sensor 10 is disposed near the negative film 2, and electrically scans the entire screen of the negative film 2 to measure the density of the image divided into many parts, which is necessary for photo printing. The negative film 2 is directly viewed to detect image information (for example, size, average density of the whole screen, contrast, maximum density, and minimum density). That is, by applying predetermined drive signals 101S to 103S from the drive circuit 20 to the image sensor 10, the two-dimensional image sensor 10 receives the transmitted light of the negative film 2 placed in the printing section via the lens system 11. Therefore, the two-dimensional image sensor 10 divides the entire negative film 2 into a large number of aligned small pixels 21 as shown in FIG.
The entire screen of the negative film 2 can be scanned in sequence according to the following. After the entire screen has been scanned, the output register section 103 of the image sensor 10
sequentially outputs the image signal PS from
The sample and hold circuit 21 samples and holds the sample value, and the AD converter 22 converts the sample value into a digital signal DS. The digital signal DS from the AD converter 22 is logarithmically converted in the logarithmic conversion circuit 23 and obtained as the concentration signal DN.
Under the control of the write control circuit 24, the DNs are stored in the memory 25 in an array corresponding to the pixels 21 as shown in FIG. 4B and as digital density values of the negative film 2. In this case, the drive circuit 20
By controlling the timing of writing into the memory 25 by inputting the reading speed signal RS from the RS, it is possible to always associate the divided pixel positions of the negative film 2 with the data array stored in the memory 25. Further, since the present invention does not use a beam splitter such as a half mirror, the influence of light absorption on the optical path is small, and highly accurate detection can be performed.

In this way, the negative film 2 is stored in the memory 25.
When digital values for each pixel or density values for each pixel related to the three primary colors are stored, the negative film 2
Digital values can be read out from the memory 25 and used for each pixel. Therefore, the three primary colors
If density values such as those shown in Figure 4B are determined and stored for each RGB, the exposure correction amount can be read out and processed by calculation etc. for each RGB. can be determined. Conventional film measurement scanners are designed to determine the photographic printing exposure amount and the exposure correction amount, but in the present invention, the optical sensor 8 determines the photographic printing exposure amount, and the two-dimensional image sensor 10 determines only the exposure compensation amount. I made it. Compared to determining the exposure amount using LATD, photometry for determining the amount of exposure correction, which corrects the subdivision area for the exposure amount, does not require as wide a dynamic range as LATD photometry, and also has less photometric accuracy. It was found that it can be used even if it is about one order of magnitude lower. From this, it has become possible to use the two-dimensional image sensor 10 by using it only for determining the amount of exposure correction. Note that the exposure correction amount can be determined using, for example, Japanese Patent Application Laid-Open No. 52
The method disclosed in Japanese Patent Application Laid-Open No. 54-28131 can be used. In this way, the conventional 2
Solving the shortcomings of dimensional image sensors, its small size,
It was used as a scanner for photo printing equipment and has many features such as low cost, simple structure, and low failure rate due to the lack of moving parts.

The image sensor 10 is composed of a predetermined number of elements, and the number of screen divisions is physically determined by the number of elements. Also, when determining the density value for each of the three primary colors, RGB, the filter 3 in FIG. This is possible by performing appropriate operations. For example, by inserting M and C filters, it is possible to sidelight B, which is the complementary color of Y. Furthermore, a filter for three RGB colors may be placed in front of the image sensor 10, and the obtained light may be obtained in synchronization with the rotation of the filter.
The colors may be separated using three dichroic filters, and the light separated into BGR may be detected by sensors for each of the three colors. Furthermore, the detection device may be constructed by closely attaching a BGR stripe filter or a BGR mosaic filter to the surface of the image sensor 10. In this case, the stripe width of the stripe filter corresponds to the pixel width of the sensor, and the mosaic elements of each color must correspond to the pixels of the sensor.
image information can be detected.

Here, we will explain 1 of the image information obtained from the photometric data.
First, the size determination of the image frames of the negative film 2 will be explained. A long negative film 2 is sequentially conveyed to a negative carrier 1 in a printing section, where, as shown in FIG. 5, a rectangular upper guide 1B having an opening 1A and a lower guide disposed below are used. 1C, the upper guide 1B and the lower guide 1C
Negative film 2 held between
It is designed to be printed frame by frame. The size of the opening 1A of the upper guide 1B completely corresponds to the frame size of the negative film 2, and the snaking part at the periphery of the frame image is the size of the opening 1A of the upper guide 1B.
It does not protrude beyond the edge of A. For this reason, 2
The area where the dimensional image sensor 10 receives light includes not only the frame images of the negative film 2 but also the non-transmitted light portion of the upper guide 1B so that it can handle large-sized negative films with ease. , the image information of the area detected by the two-dimensional image sensor 10 is as shown in FIG. 6A for a 110 size negative carrier, and as shown in FIG. 6B for a 135 size negative carrier. become. These Figure 6 A and B are
This shows an example of detected image information for a snook image (base density) when no image is taken on the negative film 2. The part surrounded by the broken line in the center is the opening 1A, that is, the area of the image frame. It shows. Here, before measuring a film image with a two-dimensional image sensor, the film base on which no image is photographed is photometered and stored as a base density or base signal, and the stored value is used when measuring the film image. to remove the base density or base signal from the image density or image signal. As a result, the Snake image (base density) is as shown in Figure 6A.
As shown in B, the concentration is 0. Setting the base density to 0 in this way is used to correct variations in the sensitivity of the photometric element, to correct differences in light intensity on the element surface due to diagonal photometry from outside the printing optical path, and to correct two-dimensional images. This is because the sensor's dynamic range is narrow, so unnecessary base concentration must be removed before photometry is performed. Note that the concentration is not necessarily 0.
There's no need to do it. For example, the base density may be set to 0.2, but in this example, the base density is set to 0 for ease of understanding. Since the size of the image frame corresponds to the size of the negative film 2, the aperture can be determined by detecting the density "0" indicating a snook from the image information read by the image sensor 10 and calculating its area. The area of 1A can be determined, and as a result, the size of the negative film 2 can be determined. In this case, image sensor 1
Since the optical axis of 0 is directed approximately to the center of the aperture 1A, by counting the number of pixels with a density of "0" (or a value near it) using hardware or software, the counted value can be calculated. The size of the negative film 2 can be determined by comparing it with a predetermined value predetermined for each size.

In this way, from the entire image information read by the image sensor 10, the opening 1A of the negative carrier 1 is determined.
The area of density "0" indicating the size of the image is counted by the number of pixels, and the size of the negative film 2 is determined from the counted value. For example, if the number of pixels with density "0" is 12 (for example, between 10 and 14 to provide a margin) as shown in Figure 6A, then
The size is determined as follows: 110 size, 135 size when there are 56 pieces (similarly, it may be between 54 and 58, for example) as shown in FIG. B, and 126 size when there are 36 to 40 pieces.

By the way, in the above description, the two-dimensional image sensor 10
is inclined with respect to the optical axis LS of the negative film 2 and the light source 4, and is provided on the axis LS' shown in FIG. The image of the negative film 2 formed on the two-dimensional image sensor 10 is distorted, making it impossible to detect correct image information. Originally the 6th
Although "0" information arranged in a rectangular manner should be obtained on the image sensor 10 as shown in Figure B, the formed image is distorted, so there is a difference in distance between near and far as shown by the broken line in Figure 7. will occur. When such image distortion occurs, a deviation occurs between the actual image and the information detected on the image sensor 10, making it impossible to accurately detect image information. In contrast, in the present invention, the two-dimensional image sensor 10 is provided parallel to the surface of the negative film 2 so as not to block the optical path from the negative film 2 to the lens system 5. When the two-dimensional image sensor 10 is provided in this way, the optical axis LS' connecting the two-dimensional image sensor 10 and the negative film 2 is the optical axis LS
The lens system 11 for forming an image of approximately the center of the negative film 2 on the optical axis LS′ in front of the two-dimensional image sensor 10
As shown in FIG. A, the lens is arranged so that its original optical axis is perpendicular to the light receiving surface of the two-dimensional image sensor 10.

Therefore, even if the two-dimensional image sensor 10 and lens system 11 are installed with the optical axis LS' tilted, the light-receiving surface of the two-dimensional image sensor 10 is parallel to the negative film 2, so distortion of the negative film 2 is prevented. The two-dimensional image sensor 10
It will be imaged on top. Therefore, for example, a negative image is no longer detected as shown in FIG. 7, but is always detected as an accurate rectangle as shown in FIG. 6B. In other words, this invention applies Camera Adjustments in photographic technology, and in order to simplify the mechanism of the printing device, the optical axis of the lens for the two-dimensional image sensor 10 is intentionally set to be perpendicular to the center of the screen. This makes it possible to accurately detect image information. The types of tilt are shift (moving the lens seat or screen frame in parallel up, down, left, or right), tilt (tilting the lens seat or screen frame upward or downward), swing, and rise fall. be.

In addition, in the above-mentioned embodiment, the optical axis of the lens system 11
The lens system 11 is arranged so that LX is perpendicular to the light-receiving surface of the two-dimensional image sensor 10, and the optical axis LX and LS' of the lens system 11 are arranged to coincide, as shown in FIG. 8B. You may do so. If the optical axis LX of the lens system 11 is arranged perpendicular to the light receiving surface of the two-dimensional image sensor 10 as in the embodiment shown in FIG. Although it is possible to focus, since the lens 11 is used with agitation, a lens with a wide image circle is required. On the other hand, the 8th
As shown in Figure B, the optical axis LX and optical axis of lens system 11
When arranged so that LS′ match, it is necessary to increase the depth of focus in order to focus over the entire surface of the two-dimensional image sensor 10, but it becomes possible to use a lens with a narrow image circle. . Furthermore, although the case where an image sensor is used as the light receiver has been described above, it is also possible to use a light receiver such as a photodiode array.

(Effects of the Invention) As described above, according to the photo printing apparatus of the present invention, the LATD is measured with a conventional optical sensor to determine the printing exposure amount, and a two-dimensional area sensor such as a charge accumulation type two-dimensional image sensor is used to measure the LATD. Since the exposure correction amount for the printing exposure amount is determined based on the measured image density, it is possible to obtain an accurate exposure correction amount, and the accuracy in determining the exposure amount is improved. Also, when measuring the image density above,
The value of the snaking part of the image information obtained from the photometric signal of the negative film image is set to 0 or around 0, and the image density of the frame image is then measured. By photometry, it is possible to correct the intensity of light on the element surface, and at the same time, it is possible to perform photometry without unnecessary snook images due to the narrow dynamic range of the two-dimensional area sensor.

In addition, the two-dimensional area sensor is arranged at an angle with respect to the axis of the optical path so that the image on the negative film can be measured from outside the optical path of the printing light that prints frame images onto photographic paper. Therefore, deterioration in the detection accuracy of image information can be avoided, and the configuration can be simple, and it can be easily added to a conventional general photo printing apparatus. moreover,
By using a two-dimensional area sensor as a photometric device that determines the amount of exposure correction for the printing exposure amount, it becomes a small, low-cost, and trouble-free photometric device.Also, since photometry can be performed without driving the film, it is easy to operate. It becomes an easy-to-use photometric device.
Therefore, it is possible to realize a small, low-cost, and high-performance photoprinting device.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of a photo printing apparatus of the present invention, Fig. 2 is a block diagram showing the functions of a two-dimensional image sensor used in the present invention, and Fig. 3 is a block diagram showing a control system of the two-dimensional image sensor. 4A and 4B are diagrams illustrating an example of the correspondence between pixel division of an original film and storage data according to the present invention; FIG. 5 is a diagram showing details of the printing section; FIGS.
B and FIG. 7 are diagrams for explaining how image information is detected, and FIGS. 8A and B are diagrams for explaining the state of image information detection.
It is a figure showing an example of composition of a dimensional image sensor. 1...Negative carrier, 2...Negative film, 3
... Filter, 4 ... Light source, 5, 11 ... Lens system, 6 ... Black shutter, 7 ... Photographic paper, 8 ... Light sensor, 10 ... Two-dimensional image sensor, 20 ... Drive circuit, 22 ...AD converter,
24...Write control circuit, 25...Memory.

Claims (1)

[Claims] 1 Separate the transmitted light of the negative film illuminated by the printing light source into red, green, and blue, measure the average photometry of the frame images to be printed on the negative film, calculate the LATD, and print each of the red, green, and blue colors. an optical sensor for determining the exposure amount; and an optical sensor disposed at an angle with respect to the axis of the optical path so that the image on the negative film can be measured from outside the optical path of the printing light that prints the frame image on photographic paper; a two-dimensional area sensor that sets a value of a snaking part of image information obtained from a photometric signal of an image of a negative film to 0 or around it, and then measures the image density of the frame image; 1. A photographic printing apparatus characterized in that an exposure correction amount is calculated based on the image density measured by the photo printing process, and printing is performed by correcting each of the printing exposure amounts.