JPH01166173A - Image reader - Google Patents

Abstract

PURPOSE:To improve processing speed by using one kind of a light source, obtaining output for the plural kinds of a drop-out color in an identical scanning timing, switching the light source and eliminating the need of the plural number of times of read. CONSTITUTION:An image sensor receives a light from a lens 1, for example, through a filter for a red color 3 and a filter for a green color 4. These filters 3 and 4 are sequentially and repeatedly disposed. Charge possessed by respective sensor light receiving parts 2 is transmitted to a CCD transferring part 6 through a transfer gate 5 and sequentially transferred by a shift clock. Thus, output signals passed through the filter 3 and 4 are repeatedly outputted by the image sensor and both of them are independently outputted in the identical scanning timing. These output signal are respectively sent to an image processing circuit for a red color 12 and an image processing circuit for a green color 13 by a demultiplexer 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reading device, and more particularly, to an image reading device that does not use multiple types of light sources or multiple image sensors.

[Conventional technology]

Conventional image OCR that supports multiple types of dropout colors has multiple types of light sources and uses a method of turning on the light source corresponding to each dropout color and reading the image. Therefore, reading the seal image,
Red dropout - When reading forms printed in color formant, the light source is switched between red and green.
It was necessary to read it frequently. Japanese Patent Laid-Open No. 55-115169 is related to this type of device.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into consideration the fact that images corresponding to a plurality of dropout colors are read in a single reading operation using one type of light source, and there is a problem in that the processing speed decreases.

An object of the present invention is to read images corresponding to a plurality of types of dropout colors in one reading.

[Means for solving problems]

The above object is achieved by providing an image sensor for reading an image of a form having all of a plurality of dropout colors, in which a light receiving section is equipped with an image sensor in which filters corresponding to each dropout color are sequentially arranged.

[Effect]

The image sensor used in the present invention has the number of pixels corresponding to the number of dropout colors of a commonly used image sensor, so for example, an image sensor for two types of dropout colors has twice the number of pixels. (The number of pixels of the image sensor is the required decomposition.

function multiplied by the number of dropout colors).

Since the outputs corresponding to each of these dropout colors are sequentially arranged on the same image sensor, signal processing for multiple types of dropout colors can be performed simultaneously by dividing the outputs for each dropout color. Furthermore, since the light receiving side has filters corresponding to each dropout color, the light source may be the same two types of light, for example, white light.

Furthermore, the shading correction required for accurate reading of image information can be corrected with a single set of shading pressure circuits by adjusting the levels for each dropout color.

〔Example〕

Figure 2 shows the configuration of conventional image OCR corresponding to two types of dropout colors. For example, red light source-8
and a green light source 9 are turned on separately according to 8 of the forms 10, and the same image sensor 7 reads them.

However, it is not possible to obtain signals for red and green at the same time.

On the other hand, the image OCR according to the present invention has an image sensor shown in FIG. The image sensor in FIG. 1 uses a filter 3 for red and a filter 4f for green, for example, to filter the light from lens 1! The filter 3 and the filter 4 are arranged one after the other in order. The image sensor shown in FIG. 1 is a CCD image sensor as an example, but the charges held by each sensor light receiving section 2 are sent to the CCD transfer section 6 via a transfer gate 5, and the charges are sequentially transferred by a shift clock. As a result, this image sensor repeatedly outputs the output signal that has passed through the red filter 3 and the green filter 4, and both are outputted independently at the same scan timing.

For this reason, in order to set the sensor density for each dropout color to, for example, 8 sensors/■, the trap uses 8 sensors for red color and 8 sensors for green color, for a total of 16 sensors/W. As shown in the third block, the output of the image sensor in FIG. By distributing the image information, it is possible to simultaneously process the sequentially output image information for red and green. Here, image sensor driver 14.
The control circuit 15 generates a control signal at a timing synchronized with the image sensor 7 and the demultiplexer 11.

〔Effect of the invention〕

According to the present invention, outputs for multiple types of dropout colors can be obtained at the same scan timing using one type of light source sound, so there is no need to switch light sources and read multiple times, improving processing speed.

Furthermore, since multiple image sensors that separate light using color filters are not used, the device can be made smaller and costs can be reduced.

In addition, since image sensors have multiple colors arranged in sequence, they are inevitably high-density sensors, but in the case of CCD image sensors, low-density sensors are difficult to commercialize. A corresponding image sensor will be obtained.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of an image sensor used for image OCR of the present invention. FIG. 2 is a conceptual diagram of image OCR corresponding to a plurality of dropout colors according to a conventional method. FIG. 5 shows a block diagram of an image OCR signal processing circuit according to the present invention. 1...Lens, 2...Sensor light receiving section, 3
．． 4... Color filter, 5... Transformer 7 Kate, 6... CCD transfer unit, 7... Image sensor, 8.9... Light source, 10... Form,
11... Demultiplexer, 12.13... Image processing circuit, 14... Image sensor driver, 15... Control circuit. A-1-1 1st Figure 1 ゛ 2nd entry//,
De'mar ÷ f 0 and 7 12, /3 picture processing circuit/4- image dead> subdriver 15 sea bream control circuit

Claims (1)

[Claims] 1. An image reading device for reading an image of a form having a plurality of dropout colors, characterized in that the image reading device is equipped with an image sensor in which a light receiving section is sequentially arranged with a filter corresponding to each dropout color.