JPS58115972A - Picture processor - Google Patents

Abstract

PURPOSE:To prevent color shift in picture processing, by reading an optical image having different chroma component of an original picture at plural image sensors, and applying photoelectric conversion to every result. CONSTITUTION:Figure shows the reation of optical image and electric signals when the image is projected to each image sensor, and (a) indicates an image 9' corresponding to a reference line and the original projected to the image sensors and a diagram 10' of the original. Fig. (b) shows the image sensors and each small window corresponds to each one bit. Fig. (c) is an output when the image of (a) is projected to the image sensors. Since the left line 9'1 at the left side of a reference line 9' corresponds to the 2nd bit of the image sensors, the 2nd bit is outputted as a dark output. Further, since the line 9'2 of the center corresponds to the 3rd and 4th bits, each intermediate value is outputted. Since the right side line 9'3 corresponds to the 5th bit, a dark output is obtained. The diagram 10' of the original is shown similarly. Fig. (d) is a binary value of the diagram 10' at a prescribed threshold value, and it is known from the output of the signal either of which out of the three reference lines, both sides or center, is read in the image sensors.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus that reads different color component optical images of an original image using a plurality of image sensors and converts them into photoelectric converters.

Move according to the picking speed. Light from the original passes through a lens 2 and is separated into colors by dichroic filters 3 and 4, and each color separated light is sent to an image sensor 5,
6 and 7 and converted into electrical signals.

It is desirable that the projection magnification is as large as possible, but it is usually 175-11 because there is a limit to the size of the image sensor.
If you want to use around 20 and want a fine-grained reproduction, set 17.
It is used in the range of 5 to 1/10. In this case, the allowable amount of color misregistration when reproducing the original is about 0.2W, and if it exceeds that, color misregistration will be visible to the naked eye, which is not preferable. When the magnification is 1/10, the color shift allowed by the image sensor is about 20 μm.

It is extremely difficult to adjust the arrangement of each image sensor within such permissible accuracy, and it has been impossible for the image processing apparatus to cause color misalignment due to installation errors of each image sensor.

The present invention has been made in view of the above points, and relates to an image processing apparatus that prevents color shift during image processing.

The present invention provides a means for generating a reference optical signal in a predetermined positional relationship with the original image in an image processing apparatus that reads different color component optical images of an original image using a plurality of image sensors and converts each optical image into an electric signal. and a plurality of image sensors arranged to receive the reference light signal from the generating means together with the color component light image. Similarly, in the present invention, different color component light images include not only a combination of color-separated light images with different wavelengths, but also a combination of such a color-separated light image and a non-color-separated light image. means.

The details of the present invention will be explained below using specific examples.

FIG. 2 shows the document surface of the image processing apparatus of the present invention. For convenience, the following explanation will be given in the case where the projection magnification is 1/10 and the size per 1 bit of the image sensor is 15 μm. In Fig. 2, reference numeral 8 shows the document placement table surface viewed from the back, and a base line 9 is drawn in the direction of the original document at the end adjacent to the transparent surface on which the document is placed. .

In this example, three reference lines are drawn, each with a line width of 0.1 mm and a center-to-center distance of 0.225 m+n.

FIG. 3 shows a partial cross section of the surface of the document table.

Reference numeral 11 denotes a transparent glass forming the document placement surface 8, on which the document 10 is placed. Reference numeral 12 denotes a plate on which the entire reference line 9 is printed, and is fixed onto the transparent glass using a pressing member 13.

This holding member 13 serves both as a holding member 12 and as a reference when placing the original document IO.

Figure 4 shows each image sensor using the same projection system as in Figure 1.
This shows the relationship between the optical image and electrical signal when projected onto. a is
A corresponding r-zoom 8' and a figure 10' of the original are shown when the reference line 9 and the original 10 are projected onto the image sensor.

X is a direction axis that intersects the document scanning direction (arrow) of FIG. 3 by one page. b is an image sensor, and each small window corresponds to 1 bit. For convenience of explanation, numbers 1 to 14 are assigned as the address of each bit. The image sensor used is an MO8 type image sensor or a CCD. C is the output when the iron of a is projected onto the image sensor. The left line 9f of the reference line 9' hits the 2bi of the image sensor on the eye, so
The th bit is output darkly. -The middle line% is 3
Since this corresponds to the th bit and the 4th bit, intermediate values are output for each. The line % on the right side appears in the 5th bit, so it is output darkly. The same applies to the original figure 10'. The value obtained by binarizing with a certain threshold value passing through this value is d. If you look at the reference line of this signal, it will be 01101, which is 7 bits.
When the image is zoomed and projected, the output becomes 11011. From the way this signal is output, it can be determined whether the two ends of the three reference lines or the middle one is being read by the image sensor.

When the lines g5g6 at both ends are read, for example, the processing signal strength of the original signal is 5 at the 4th bit from the reference line signal.
Processing of the original signal starts at the bit. If the start timing of document signal processing is set while determining the reference line signal in this way, the reading position error can be kept within 1 bit. This means that no matter how the image sensor is installed, it is possible to know the timing to process the original signal without color shift just by reading out the reference line signal and identifying which line the signal belongs to. That is,
Synchronization of each image sensor can be obtained using the reference line signal. Further, if the relative relationship between the document and the reference line on the document placement surface is constant, the document can be read without waste.

Therefore, no matter how many image sensors there are, each can be mounted at a position that receives the original optical image and the reference optical signal, and therefore, their mounting does not require much precision. Then, as in the above example, the positional relationship of those images can be kept within an error of 1 bit. Therefore, in this device, 0.15 mm
Since it is possible to keep the color deviation within the range of 200 to 3000, this is extremely good in practice.

In the above example, three mark-containing members were installed on the document placement surface as members that emit reference light signals, but to explain this, an independent illumination source was provided without using the illumination light of the document placement surface. It's okay. Further, instead of using a mark member having a reflective part, a partially transparent part may be provided, and a light source may be placed on the back side.

In the above-mentioned specific example, the signal detected first by the image sensor among the input optical signals of each mark is used as the reference line. By the way, if there is a possibility of erroneous reading due to dust on the document surface other than the mark member, the reference line may be marked with three stars to make the reading system recognize the reference line signal as the reference line, or It is also effective to increase the line width and improve the discrimination accuracy.

As described above in detail in the specific examples, the present invention enables signals read by a plurality of image sensors to be processed without mutual deviation. Therefore, when a color image is formed using the signals obtained by the image processing device, smooth image formation is possible without causing any color misregistration.

FIG. 1 is a schematic diagram illustrating the configuration of an image processing apparatus according to the invention; FIG. Figure 4 is a schematic diagram illustrating the conversion of the image sensor of the device of the present invention into human-powered light 1. 1, 10; original 2; lenses 3, 4; dichroic mirrors 5, 6, 7; image sensor 8; , lTi mounting table 9; - Reference line (mark member) Applicant: Canon Co., Ltd. 7], "°? 1st, i Agent: Gi Marushima -□ ・: Lt, ', - 13 views

Claims (1)

[Claims] (1) In an image processing device that reads different color component optical images of an original image using a plurality of image sensors and converts each one photoelectrically, means for generating a reference optical signal in a predetermined positional relationship with the original image; An image processing apparatus comprising a plurality of image sensors arranged to receive the reference light signal from the generating means together with the color component light image. (2. In the invention set forth in claim 1, the reference optical signal generating means has a mark member disposed adjacent to the original image mounting surface and having a predetermined reflective part and a non-reflective part. Characteristic image processing device.