JPS61208356A - Picture reader - Google Patents

Abstract

PURPOSE:To read always a picture accurately while preventing stray light by providing a stray light preventing means between plural image pickup elements and a color separation filter. CONSTITUTION:A light shield mask 7 is provided between a 3-color separation filter 4 and a dust-proof glass 6. The luminous flux passing through an image forming lens is formed on an image pickup element 5 corresponding to the filter 4. Further, the light shield mask 7 receives no image forming luminous flux and shuts other flair light A, and the flair light A is absorbed by the mask. Thus, only the luminous flux transmitting through the corresponding filter 4 is formed to the image pickup element 5 and the picture is read always accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field - The present invention relates to an image reading device, and particularly to a reading section of a color image reading device.

(2) Prior Art Conventionally, many devices of this type are usually equipped with a plurality of image sensor arrays, and in order to accurately read color images, they must be equipped with a color separation filter and a plurality of image sensor arrays. There is.

For example, FIG. 1 shows an example of an optical system in a color image reading device, which is equipped with a three-column image sensor array. Here, 1 is the manuscript.

1' is the original voice glass, 2 is the imaging lens, and 3 is the aperture.

4 is a 3-point separation filter corresponding to R, G, B or C, M, Y In the figure, A in the figure indicates flare light. In general, a color image reading device illuminates a document 1 and scans the document or scans the illumination system, using an optical system such as that shown in the first factor, to apply boiling to a color separation filter.
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An image is formed on the corresponding image sensor 5. however,
When using a general optical system, as shown in No. 21ffl, each image sensor 5 receives light beams outside the front end that are multiplexed on the back surface of the dust-proof glass 6, three-color separation filter 4, etc. on the image sensor 5. The light flux that is reflected and passed through other color filters is irradiated as flare light A onto an uncorresponding image sensor 5. Therefore, the flare light A has become an obstacle to accurately reading images.

(3) Summary of the Invention An object of the present invention is to eliminate the conventional drawbacks and provide an image reading device capable of accurate reading.

In order to achieve the above object, an image reading device according to the present invention includes a plurality of image sensors, and the plurality of image sensors are arranged in correspondence with color separation filters. The present invention is characterized by having a stray light prevention means between the color separation filter and the color separation filter.

As the stray light prevention means, any member may be used and any configuration may be used as long as it does not obstruct the course of the light flux to be imaged on each image sensor and has the function of blocking only flare light, and multiple imaging devices may be used. Methods include providing a light shielding mask between the element and the color separation filter, applying anti-reflection treatment between the image pickup elements, and preventing multiple reflections of the light flux that becomes flare light.

Hereinafter, the present invention will be explained in detail with reference to Examples.

(4) Embodiment FIGS. 3 and 4 show an example of an image reading device according to the present invention, in which FIG. 3 is an enlarged view of the reading section, and FIG. 4 is a perspective view of the reading section. Here, 7 is a light shielding mask, and the same members as in FIG. 2 are given the same numbers.

The basic structure of the image reading device in this embodiment is the same as that of the device shown in FIG. Here, the light beam passing through the imaging lens is filtered through a three-color separation filter 4.
The images are formed on the corresponding image sensors 5 via the respective images. Further, the light-shielding mask 7 is provided so as not to eclipse the imaging light flux but to shield the other flare light A, and the flare light A is absorbed by the light-shielding mask. Therefore, only the light flux that has passed through the corresponding color separation filter 4 is always imaged on the image sensor 5, and accurate images can be read at all times.

In the above embodiment, a light-shielding mask was used to block flare light, but as mentioned above, various methods can be used, such as providing an anti-reflection film on a predetermined member to prevent multiple reflections and hinder the generation of flare light. Various applications exist as long as they do not deviate from the idea of the present invention.

(5) Detailed Description of the Invention As described above, the image reading device according to the present invention prevents stray light and is capable of always accurately reading images.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an optical system in a conventional image reading device, FIG. 2 is an enlarged view of the device shown in FIG. 1, and FIG. 3 is a configuration diagram of a reading section of an image reading device according to the present invention. FIG. 4 is a perspective view of the reading section shown in FIG. 3. 1-111 Original 1'-1--Original platen glass 2----
Imaging lens 3-111 aperture 4----3 color separation filter 5-111 imaging element 6----dust-proof glass 7-
--- Light blocking mask A --- Flare light

Claims (1)

[Claims] (1) An image reading device including a plurality of image sensors, the plurality of image sensors arranged corresponding to color separation filters, including a stray light prevention means between the plurality of image sensors and the color separation filters. An image reading device characterized by: