JP2000165598A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader that can correct color slurring with high precision by absorbing fluctuation in a carrying speed of an original so as to simplify the control. SOLUTION: A green G color separation filter 150 is fitted to an R(red), G(green), B(blue) line CCD sensor unit 94 to read an image recorded on a negative film 20 so that the same spectral sensitivity is provided at the same position of R, G, B line CCD sensors 94R, 94G, 94B, and the image data read by the part fitted with the G color separation filter 150 are used to detect a position deviation among the 3-line CCD sensors so as to correct color slurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus, and more particularly to an image reading apparatus for reading an image recorded on a photographic material such as a photographic film.

[0002]

2. Description of the Related Art Photosensitive materials such as photographic films (hereinafter referred to as "photosensitive materials").
In a conventional photographic processing system for processing an image recorded on a photographic film), an image recorded on the photographic film is photoelectrically read by an imaging device such as a line CCD sensor, and the read digital image data is read. Image processing such as various corrections, and forms an image on a recording material by a laser beam modulated based on the digital image data after the image processing.

In such a conventional photographic processing system,
An image reading device used for reading an image recorded on a photographic film is to use a three-line CCD sensor in which line CCD sensors having respective spectral sensitivities of R, G, and B are arranged at regular intervals. General.

In a conventional three-line CCD sensor, it is necessary to correct a color shift between three colors in order to obtain a high-quality image. In general, a correction amount is calculated from the moving speed of the document and the correction amount is used.

[0005]

However, in the conventional color misregistration correction, the optical magnification for projecting an original onto a line CCD sensor and the transport speed of the original are detected and calculated, so that complicated control is required. Therefore, there is a problem that the accuracy of the color misregistration correction is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and provides an image reading apparatus capable of absorbing a change in the conveying speed of a document and simplifying the control to perform highly accurate color misregistration correction. Aim.

[0007]

According to a first aspect of the present invention, there is provided an image reading apparatus comprising a plurality of image pickup means having different spectral sensitivities for reading images of at least two colors recorded on a document. Providing a portion having the same spectral sensitivity in a predetermined portion of the plurality of imaging means,
The method is characterized in that the image data read by the portion having the same spectral sensitivity is used to correct the positional deviation of the image obtained for each of the plurality of imaging units.

According to the first aspect of the present invention, there is provided an image reading apparatus comprising a plurality of image pickup means having different spectral sensitivities for reading images recorded on an original of at least two colors. A portion having the same spectral sensitivity is provided in a predetermined portion of the imaging means, and the same image is read by the portion having the same spectral sensitivity. By superimposing the image data of the plurality of imaging units obtained by reading, it is possible to detect a positional shift of an image generated for each of the plurality of imaging units. By controlling the displacement of the image on the image data, the displacement of the image generated for each of the plurality of imaging units can be corrected. In other words, it is possible to correct the image misalignment that occurs for each of the plurality of imaging units only by using the image data read by the plurality of imaging units without using the optical magnification and the conveyance speed of the original projected from the original to the imaging unit. it can. For example, the present invention can be applied to color shift correction when a color image is read using a plurality of line CCD sensors or a plurality of area CCD sensors.

The invention according to claim 2 is characterized in that the imaging means is a three-line CCD sensor having R, G, and B spectral sensitivities.

According to the second aspect of the present invention, it has R (red), G (green), and B (blue) spectral sensitivities,
By giving the same spectral sensitivity to a predetermined part of a three-line CCD sensor arranged at a predetermined interval, a three-line CCD sensor is provided.
From the image data of the same image read by the part having the same spectral sensitivity of the D sensor, R, G, and B lines C
Since an image shift (color shift) in the sub-scanning direction that occurs for each CD sensor can be detected, color shift correction can be performed by controlling the delay time of each of the R, G, and B line CCD sensors. .

For example, by attaching a G filter to a part of the three-line CCD sensor of R, G, and B, the same spectral sensitivity is given to a predetermined part of the three-line CCD sensor. G
In the portion where the filter is attached, each line CCD sensor can recognize the same image as the same image data. That is, using the same image data, the deviation of the image data read by each line CCD sensor is corrected by controlling the delay time for each line CCD sensor, and 3
The color misregistration of the line CCD sensor can be corrected.
Therefore, since the control is based only on the use of image data regardless of the optical magnification for projecting the original onto the line CCD sensor and the transport speed of the original, the control can be simplified and the cost of the apparatus can be reduced. .

According to a third aspect of the present invention, the different spectral sensitivities and the same spectral sensitivities are provided with spectral sensitivities by spectral means including at least a color separation filter and a dichroic prism.

According to the third aspect of the present invention, a spectral means such as a color separation filter and a dichroic prism is provided to give different spectral sensitivities and the same spectral sensitivity to the plurality of image pickup means. Thereby, a plurality of imaging units can use the same imaging unit. For example, by using three monochromatic line CCD sensors, using a color separation filter, a spectral means such as a dichroic prism,
R, G, and B three-line CCD sensors can be used. Similarly, spectral means such as a color separation filter and a dichroic prism are provided in order to make predetermined portions at the same position have the same spectral sensitivity in the three-line CCD sensor. Alternatively, a portion that does not have spectral sensitivity is provided for R, G, and B. In this manner, a color image can be obtained by reading at portions having different spectral sensitivities, and color misregistration can be corrected using image data read at portions having the same spectral sensitivity. That is, since the control is based only on the use of image data regardless of the optical magnification for projecting the original onto the line CCD sensor and the transport speed of the original, the control can be simplified and the cost of the apparatus can be reduced. .

The invention according to a fourth aspect is characterized in that the correction uses a bar code attached to a photographic material.

According to the fourth aspect of the present invention, a bar code attached to a photographic material such as a photographic film can be used for correcting the above-described positional displacement of an image for each image pickup means.

For example, a terminal portion of each of the line CCD sensors of the R, G, and B line CCD sensors has the same spectral sensitivity, a color image is read by a portion having the R, G, and B spectral sensitivities, and the same spectral sensitivity is read. The bar code attached to the photographic light-sensitive material is read at the portion having. By overlapping the bar code pattern of the read image data, the displacement (color misregistration) of the three line CCD sensors
Can be detected, and the color shift of each line CCD sensor can be corrected by controlling the delay time. That is, since the control is based only on the use of image data regardless of the optical magnification for projecting the original onto the line CCD sensor and the transport speed of the original, the control can be simplified and the cost of the apparatus can be reduced. .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to a photographic processing system. FIG. 1 shows a schematic configuration of a photographic processing system 10 according to the present embodiment.

The photographic processing system 10 includes a film scanner 12, an image processing section 14, a laser printer section 16, and a processor section 18, as shown in FIG.

A frame image recorded on a photographic material (hereinafter simply referred to as a photographic film) is read by a film scanner 1.
2 and output to the image processing unit 14 as scan image data. The image processing unit 14 receives the scanned image data output from the film scanner 12 and reads image data obtained by photographing with a digital camera and a document (for example, a reflection document) other than a film image with a scanner. The obtained image data, image data generated by a computer, and the like (hereinafter, referred to as file image data) are externally input (for example, input via a storage medium such as a memory card, or via a communication line). Input from another information processing device, etc.).

The image processing section 14 performs various types of image processing such as various corrections on the input various image data, and outputs the processed image data to the laser printer section 16 as recording image data. Further, the image processing unit 14 outputs the image data subjected to the image processing to an external device as an image file (for example, outputs the image data to a storage medium such as a memory card, or transmits the image data to another information processing device via a communication line). Etc.) are also possible.

The laser printer section 16 is provided with R, G, and B laser light sources. The laser printer section 16 irradiates a photographic paper with a laser beam modulated in accordance with the image data for recording input from the image processing section 14 to perform scanning. An image is recorded on photographic paper by exposure.
Further, the processor unit 18 performs each process of color development, bleach-fixing, washing, and drying on the photographic paper on which the image is recorded by the scanning exposure by the laser printer unit 16. Thus, an image is formed on the printing paper.

As shown in FIG.
Inside the pre-scan unit 3 along the film transport path
6, the fine scan unit 38 is arranged in order. Each of the scanning units 36 and 38 scans and reads an image recorded on the negative film 20 as described later.

An insertion detection sensor 40 is provided upstream of the film transport path. The insertion detection sensor 40 is configured such that a pair of a light emitting element 40A and a light receiving element 40B are opposed to each other across a film transport path. Light receiving element 40B
Are connected to the control circuit 42. The control circuit 42 determines whether or not the negative film 20 has been inserted into the film transport path of the film scanner 12 based on a change in the level of the signal output from the light receiving element 40B.

The insertion detection sensor 40 and the prescan section 36
A pair of rollers 44 for nipping and transporting the negative film 20 are disposed between the rollers.

On the other hand, the pre-scan section 36 includes a lamp 52 arranged to emit light toward the negative film 20 passing through the pre-scan section 36. The lamp 52 is connected to the control circuit 42 via a driver 54, and the magnitude of the voltage supplied from the driver 54 is controlled by the control circuit 42 so that the amount of emitted light becomes a predetermined value. You. On the light emission side of the lamp 52, three colors of C (cyan), M (magenta) and Y (yellow) are provided.
A CC filter group 56 composed of one CC filter and a light diffusion box 58 are arranged in this order, and further, an imaging lens 60 and a CCD area sensor 62 with a film transport path interposed therebetween.
Are arranged in order.

Each CC filter of the CC filter group 56 is
The amount of insertion into the optical path is adjusted in advance in order to correct variations in the sensitivity of the R, G, and B colors in the CCD area sensor 62. Light sequentially transmitted through the CC filter group 56, the light diffusion box 58, the negative film 20, and the imaging lens 60 irradiates the light receiving surface of the CCD area sensor 62.

The CCD area sensor 62 includes a sensor for detecting the amount of R light, a sensor for detecting the amount of G light, and a sensor for detecting the amount of B light adjacent to each other. 20 along the width of
Zero and 300 along the longitudinal direction are arranged in a matrix. Therefore, the CCD area sensor 6
Reference numeral 2 divides an image into 200 × 300 pixels each having the size of one side of the sensor unit, and detects the amount of transmitted light for each pixel.

On the other hand, the imaging lens 60 receives the frame image to be read recorded on the negative film 20 and the light transmitted through the region including both ends in the width direction of the negative film 20 by the CCD area sensor 62. Form an image on the surface.

On the output side of the CCD area sensor 62, an amplifier 64, a LOG converter 66, and an A / D converter 68 are sequentially connected. The signal output from the CCD area sensor 62 is amplified by the amplifier 64, logarithmically converted (converted to a level corresponding to the density value) by the LOG converter 66, and corresponds to the signal level by the A / D converter 68. The value is converted to digital data. The A / D converter 68 is connected to the control circuit 42, and the converted digital data is input to the control circuit 42 as density value data.

Further, between the pre-scanning section 36 and the fine scanning section 38, a roller group including a transport roller pair 74 and a driven roller 76, and driven rollers 78A, 78
B and 78C are arranged at a predetermined distance from each other. A loop of the negative film 20 is formed between the two roller groups. By this loop, the transport speed of the negative film 20 in the pre-scan unit 36,
The difference from the transport speed of the negative film 20 in the fine scan unit 38 is absorbed.

A pulse motor 80 is connected to the transport roller pair 74. The pulse motor 80 is connected to the control circuit 42 via a driver 82. The control circuit 42 conveys the negative film 20 by driving the pulse motor 80 via the driver 82.

In the vicinity of the upstream side of the pair of conveying rollers 74 and the vicinity of the downstream side of the driven rollers 78B and 78C, the loop management sensors 83A and 83B connected to the control circuit 42 are provided.
Are arranged. The loop management sensors 83A and 83B according to the present embodiment detect a mark (for example, a splice) on the negative film 20. The control circuit 42 controls the loop management sensor while the negative film 20 is being conveyed. The counting by the counter (not shown) provided in the control circuit 42 is started when the mark is detected by 83A, and the counting by the counter (not shown) is stopped when the same mark is detected by the loop management sensor 83B. The length of the loop (the length of the negative film 20 forming the loop) can be detected based on the count value obtained by the above.

On the other hand, the fine scan section 38 has substantially the same configuration as the pre-scan section 36. That is,
The fine scan unit 38 includes a lamp 84 that emits light toward the negative film 20. The lamp 84 is connected to the control circuit 42 via a driver 86, and the control circuit 42 controls the magnitude of the voltage supplied from the driver 86 so that the emitted light has a predetermined light amount. On the light exit side of the lamp 84, a C comprising three CC filters
A C filter group 88 and a light diffusion box 90 are arranged in this order.
2. Line CCD sensor units 94 are arranged in order.

Each CC filter of the CC filter group 88 is
In order to correct variations in the sensitivity of the three colors R, G, and B in the line CCD sensor unit 94, the amount of insertion into the optical path is adjusted in advance. Light sequentially transmitted through the CC filter group 88, the light diffusion box 90, the negative film 20, and the imaging lens 92 irradiates the light receiving surface of the line CCD sensor unit 94.

The line CCD sensor unit 94 is a three-line CCD sensor unit including three line CCD sensors 94R, 94G, and 94B. As shown in FIG. 3, the three-line CCD sensor unit 94 is arranged along the width direction of the negative film 20. Line CCD
In the sensor 94R, an R color separation filter is attached to a portion for reading an image area (frame image portion) of the negative film 20 so that R (red) has a spectral sensitivity, and a bar code attached to the negative film 20 is read. A G color separation filter 150 is attached to the reading portion so that G (green) has spectral sensitivity. In the line CCD sensor 94G, a G color separation filter 150 is attached to the image area of the negative film 20 and a portion where the bar code is read so that G has spectral sensitivity, and the line CCD sensor 94B is connected to the image area of the negative film 20. A portion for reading B is provided with a B color separation filter so as to have a spectral sensitivity to B (blue), and a portion for reading a bar code of the negative film 20 is provided with a G color so as to have spectral sensitivity for G (green). Decomposition filter 1
50 is attached. That is, all of the three line CCD sensors 94R, 94G, and 94B that read the barcode area of the negative film 20 are G
A color separation filter 150 is attached.

In a conventional three-line CCD sensor having conventional R, G, and B spectral sensitivities, even if the same image is read, different read data is obtained.
Although color shift correction cannot be performed using the read data from the CD sensor, the line C
By providing a part of the CD sensor with the same spectral sensitivity, it is possible to perform color misregistration correction using the read data of the parts of the three line CCD sensors having the same spectral sensitivity. That is, since the color shift can be corrected regardless of the optical magnification projected onto the line CCD sensor unit 94 and the transport speed of the negative film 20, the control can be simplified and the color shift can be corrected with high accuracy. The color misregistration correction is performed by using the bar code portion of the negative film 20 as described above with the line CCD sensor unit 94.
(G color separation filter 15) having the same spectral sensitivity
0), and the amount of deviation is controlled by controlling the delay time for each frame image of the negative film 20 so that the respective read image data overlap (so that the barcode patterns overlap).

Further, the line CCD sensor unit 94 in the present embodiment
4R, 94G, and 94B correspond to an image area along the width direction of the negative film 20, and 1000 photoelectric conversion units (for 1000 pixels) are arranged.

Accordingly, the line CCD sensor unit 94
Represents a large number of images (1000 in the image area in this embodiment).
), And the amount of transmitted light is detected for each pixel.
The image forming lens 92 converts the light transmitted through the one pixel array along the width direction of the negative film 20 that crosses the optical axis of the light emitted from the lamp 84 among the light transmitted through the negative film 20 into a line CCD. An image is formed on the light receiving surface of the sensor unit 94.

Each line CCD sensor unit 9
4 has an amplifier 96, a LOG converter 98, and an A /
The D converter 100 is connected in order. The signal output from the line CCD sensor unit 94 is amplified by the amplifier 96, converted to a level corresponding to the density value by the LOG converter 98, and then converted to digital data by the A / D converter 100. The A / D converter 100 is connected to the control circuit 42, and the converted digital data is input to the control circuit 42 as density value data.

The control circuit 42 has an image buffer 70 capable of storing density value data of several images, and stores the input density value data in the image buffer 70. Also,
A CRT display 72 is connected to the control circuit 42 and performs processing using the input density value data.
A positive image is displayed on the CRT display 72.

The control circuit 42 calculates the amounts of exposure of the R, G, and B colors to the photographic paper based on the density value data. The control circuit 42 is connected to the laser printer unit 16,
The data representing the calculated exposure amount is stored in the laser printer unit 1.
Transfer to 6.

A transport roller pair 102 is arranged downstream of the fine scan section 38. Transport roller pair 102
Also, a pulse motor 104 is connected. The pulse motor 104 is connected to the control circuit 42 via a driver 106. The control circuit 42 conveys the negative film 20 by driving the pulse motor 104 via the driver 106.

Next, the operation of the present embodiment will be described.

The image recorded on the negative film 20 of the negative film 20 set on the film scanner 12 is read by the CCD area sensor 62 of the prescan unit 36. The read image data is supplied to an amplifier 64.
The signal is logarithmically converted (converted to a level corresponding to the density value) by the LOG converter 66, converted to digital data having a value corresponding to the signal level by the A / D converter 68, and output to the control circuit 42. Is done.

Subsequently, in the control circuit 42, the reading conditions to be performed by the fine scan unit 38 are determined based on the prescan result by the prescan unit 36. The reading conditions at the time of the fine scan are, for example, negative film 2
Negative film 2 for controlling the optical magnification and the resolution in the sub-scanning direction, which are changed by the frame image size or the like recorded at 0
And a transport speed of 0.

When the fine scan reading conditions are determined by the control circuit 42, reading by the fine scan unit 38 according to the determined reading conditions is started.

In the fine scan section 38, the transport of the negative film 20 is started, and reading by the line CCD sensor unit 94 is performed. The image area of the negative film 20 is read at a portion of the line CCD sensor unit 94 having spectral sensitivities of R, G, and B, and a negative portion of the line CCD sensor unit 94 (G color separation filter 150) having the same spectral sensitivity. The bar code portion recorded on the film 20 is read. The read data of the image area and the data of the barcode portion are output to the control circuit 42.

In the control circuit 42, color misregistration is corrected for each frame image recorded on the negative film 20 based on the read data of the three line CCD sensors 94R, 94G and 94B in the bar code portion. As described above, the color misregistration correction is performed for the three line CCD sensors 94R, 94G, and 9R.
Read data (barcode pattern) of the portion (G color separation filter 150) having the same spectral sensitivity of 4B
Are controlled by controlling the delay time for each of them so as to overlap. That is, since the correction is performed by controlling the image data read by the line CCD sensor unit 94 and the delay time, highly accurate color misregistration correction can be performed.

Subsequently, the fine scan data having undergone the color misregistration correction is output to the image processing unit 14, where image processing such as various corrections is performed by the image processing unit 14, and the laser printer unit 16 is provided as recording image data. Output to The laser printer section 16 irradiates the photographic paper with laser light modulated according to the input recording image data, records the image on the photographic paper by scanning exposure, and prints the image on the photographic paper to the processor section 18. Convey paper. Processor section 18
In, the photographic paper on which an image is recorded is subjected to color development, bleach-fixing, washing, and drying to form an image on the photographic paper.

The film scanner 1 according to the present embodiment
In the color misregistration correction of 2, the color misregistration correction is performed for each frame image. However, the color misregistration correction may be performed when the scanning conditions (optical magnification, transport speed, etc.) of the fine scan are changed.

In this embodiment, the parts having the same spectral sensitivity of the respective line CCD sensors 94R, 94G, and 94B have the same spectral sensitivity by attaching the G color separation filter 150. However, the present invention is not limited to this. Alternatively, the same spectral sensitivity may be obtained by using an R color separation filter, a B color separation filter, no filter, and the like.
In addition, each color separation filter is configured to be attached to the line CCD sensor. However, the present invention is not limited to this, and it is also possible to apply a single color line CCD sensor using a color separation filter, a dichroic prism, or the like. is there.

Further, in the present embodiment, the R, G, B line CCD sensors have been described as an example. However, the present invention is not limited to this, and the present invention is applicable to an apparatus for correcting a displacement using a plurality of image pickup means. It is possible. For example, when an image is read using three area CCD sensors having spectral sensitivities in R, G, and B, a part having the same spectral sensitivity is provided in a part of each area CCD sensor that reads the same image. For example, color shift correction using image data read by the area CCD sensor is possible.

Although the present embodiment has been described by taking a photographic processing system as an example, the present invention is not limited to this, and it is not limited to a reflective original such as a color copier, a telecine converter, a facsimile, or a transparent original. The present invention is applicable to any image reading device that requires image quality.

[0054]

As described above, according to the present invention, there is an excellent effect that high-precision color misregistration correction can be performed by absorbing fluctuations in the document conveying speed and simplifying the control.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a photographic processing system according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a film scanner.

FIG. 3 is a diagram showing a schematic configuration and a reading position of a line CCD sensor.

[Explanation of symbols]

 Reference Signs List 10 photo processing system 12 film scanner 20 negative film 94 line CCD sensor unit 94R line CCD sensor 94G line CCD sensor 94G line CCD sensor 150 G color separation filter

Claims (4)

[Claims] 1. An image reading apparatus comprising: a plurality of image pickup units having different spectral sensitivities for reading images of at least two colors recorded on a document; An image reading apparatus, comprising: a portion having a spectral sensitivity; and correcting a positional shift of an image obtained for each of the plurality of imaging units by using image data read by the portion having the same spectral sensitivity. . 2. The image reading apparatus according to claim 1, wherein said plurality of image pickup means are three-line CCD sensors having R, G, and B spectral sensitivities. 3. The image reading apparatus according to claim 1, wherein the different spectral sensitivities and the same spectral sensitivities are given spectral sensitivities by spectral means including at least a color separation filter and a dichroic prism. 4. The image reading apparatus according to claim 1, wherein the correction is performed using a bar code attached to a photographic photosensitive material.