JPH035744A - Image reader - Google Patents

Abstract

PURPOSE:To read image information projected on a screen at high accuracy by projecting an image via a mirror arranged in front of the light receiving plane of an image reading means or moving at least one mirror composing a projecting system. CONSTITUTION:The image 1 illuminated by an illuminating system 11 is projected on the screen 6 by the projecting system 12 via a reflecting means. When the image reading means 7 provided in the vicinity of the screen 6 is allowed to scan the screen 6 to read the image information projected on the screen 6, the mirror 9 is arranged in front of the light receiving plane 7a of the image reading means 7. One of the mirrors 2, 3 and 5 composing the reflecting means is moved so that the length of an optical path from the image 1 to the light receiving plane 7a is equal to the length of an optical path from the image 1 to the screen 6. Consequently, the image information can be read out at high accuracy without the distortion of the entire screen and magnification errors.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an image reading device, and more particularly, to an image reading device that transfers a transmissive image exclusively for microfilm or O) I+3 (overhead projector) onto a screen surface -F using a projection system. The present invention relates to an image reading device suitable for projecting images, observing five image information on the screen surface, and reading the image information on the screen surface with an image reading means, for example, when printing on a digital printer.

(Prior art) Conventionally, an image of a transmission type such as a microfilm is enlarged and projected onto a screen surface F using a projection system for observation, and the image information projected onto the screen surface is read using, for example, a linear light-receiving element. Various types of image r'Il reading devices: 4 have been proposed, which read the image with a digital printer and print it with a digital printer.

FIG. 3 is a schematic diagram of the main parts of a conventional image reading device of this type.

In the figure, a transmission type image 1 illuminated by an illumination system 11 is enlarged and projected onto a screen 6 by a projection system 12 via a mirror 2.3.5. Then, the image information projected onto the screen surface 6 is observed.

Also, if you want a copy of the image information projected on the screen surface 6, an image reading means 7 provided near the screen surface 6 is used.
is scanned along the screen surface 6 in the direction of arrow 10, and the image information is read photoelectrically and printed using, for example, a digital printer.

(Problems to be Solved by the Invention) In the conventional image reading device shown in FIG. ing.

Generally, the light receiving element 7a is optically located at a certain distance in front of the screen 6.

Therefore, unlike the image information projected on the screen 6, the image information on the light receiving element 78 is predetermined. Day focused image information is formed.

For this reason, when reading image information by scanning the light receiving element 7a over the screen 6, a magnification error occurs based on day focus, and there is a problem in that it is difficult to accurately read without magnification error over the entire screen. Ta.

The present invention disposes a mirror in front of the light receiving surface of the image reading means, and reads image information projected onto the screen surface through the mirror or by moving at least one mirror of the projection system. It is an object of the present invention to provide an image reading device that can accurately read the entire screen without magnification error or distortion, for example.

(Means for Solving the Problems) The image reading device of the present invention projects an image illuminated by an illumination system onto a screen surface via a reflection means by a projection system, and also provides image information projected onto the screen surface. When reading an image by scanning an image reading means provided near the screen surface along the screen surface, a mirror is placed in front of the light receiving surface of the image reading means, and the optical path length from the image to the light receiving surface is The present invention is characterized in that at least one mirror constituting the reflecting means is moved so that ≦approximately equal to the optical path length from the image to the screen surface.

(Example) FIG. 1 is a schematic diagram of main parts of a first embodiment of the present invention.

In the figure, l is a transmission type image such as microfilm or OHP.

Reference numeral 11 denotes an illumination system that illuminates one image l.

Reference numeral 12 denotes a projection system, which reflects the image l illuminated by the illumination system 11 by mirrors 2 and 3.5 constituting a reflecting means, and then projects it in an enlarged manner onto a transmissive screen 6.

Then, the image information enlarged and projected onto the screen 6 is observed.

Reference numeral 7 denotes an image reading means, which includes, for example, a light receiving means in which a plurality of linear light receiving elements are arranged in a direction perpendicular to the paper surface. 7a
is the light receiving surface of the image reading means 7. Reference numeral 9 denotes a mirror which corrects the optical path length due to the arrangement of the image reading means 7 in front of the screen 6, so that the optical path length from the image l to the light receiving surface 7a and the optical path length from the image 1 to the screen 6 are approximately equal. The light receiving surface 7a is arranged in front of the light receiving surface 7a.

The image reading means 7 and the mirror 9 are integrally moved along the screen 6 in the direction of the arrow 10 by a drive means such as a guide rail or a drive wire (not shown), thereby reading the image information on the screen 6. Is going.

In this embodiment, as shown in the figure, a mirror 9 is arranged in front of the light receiving surface 7a so as to satisfy the conditions described in πI, and the optical path lengths from the image 1 to the light receiving surface 7a and from the image 1 to the screen 6 are determined. Through this adjustment, image information projected onto the screen 6 and optically clear image information are photoelectrically read by the light receiving surface 7a.

This makes it possible to read image information across the entire screen with high precision without magnification errors or distortions.
For example, I am trying to print the information on the petition using a digital printer.

FIG. 2 is a schematic diagram of main parts of a second embodiment of the present invention.

In this embodiment, instead of arranging the mirror 9 in front of the light receiving surface 7a as in the first embodiment of FIG. 1, a part of the mirror 3.5 constituting the reflecting means is made movable to adjust the optical path length. It is characterized by

That is, when the image 1 illuminated by the illumination system 11 is enlarged and projected onto the screen 6 by the projection system 12, the mirror 3.5 is placed at the X-ray position and the image information is projected onto the screen 6. There is.

When the image reading means 7 reads the image information projected onto the screen 6, the mirror 3.5 is moved in parallel to the positions 3a and 5a shown by the dashed line, and the optical path length from the image 1 to the light receiving surface 7a is adjusted. It is made to be approximately equal to the optical path length from the image l to the screen 6 before the mirror 3.5 is moved.

As a result, as in the first embodiment shown in FIG. 1, the knee image reading means 7 reads image information that is optically equivalent to the image information projected onto the screen 6.

In this embodiment, the distance from the screen 6 where the image reading means 7 is arranged is determined according to the distance 9 from the mirror 3.
．． It is only necessary to move 5, and it can be placed at any position α.

Further, in this embodiment, the optical path length is adjusted by moving the mirror 3.5, but the optical path length from the image 1 to the light receiving surface 7a and the optical path length from the image 1 to the screen 6 can be made shorter. Any method 1 can be applied, for example, a method in which the projection system 12 and the image @1 are moved, or one or more mirrors are moved.

(Effects of the Invention) According to the present invention, when image information projected onto the screen surface is read by the image reading means disposed in front of the screen, the optical path length from the image to the light receiving surface and the image information are determined by the above-mentioned means. By setting the optical path length from It is possible to achieve an image forming apparatus that can perform

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic diagrams of essential parts of first and second embodiments of the present invention, respectively, and FIG. 3 is a schematic diagram of a conventional image reading apparatus. In the figure, 1 is an image, 2.3.5 is a mirror, 6 is a screen,
7 is an image reading stage, 7a is a light receiving surface, 9 is a mirror, 11
is the illumination system, and +2 is the projection system. Lecture] Figure

Claims (2)

[Claims] (1) The image illuminated by the illumination system is projected by the projection system onto the screen surface via the reflection means, and the image information projected onto the screen surface is transferred to the screen by an image reading means provided near the screen surface. When reading by scanning along a surface, a mirror is placed in front of the light receiving surface of the image reading means, and the optical path length from the image to the light receiving surface is approximately equal to the optical path length from the image to the screen surface. An image reading device characterized in that: (2) The image illuminated by the illumination system is projected by the projection system onto the screen surface via the reflection means, and the image information projected onto the screen surface is transferred to the screen by an image reading means provided near the screen surface. At least one mirror constituting the reflecting means is arranged so that when reading by scanning along a surface, the optical path length from the image to the light receiving surface is approximately equal to the optical path length from the image to the screen surface. An image forming apparatus characterized by being moved.