JPS6189766A - Original reading device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a document reading device for reading document images using, for example, a digitally controlled copying machine or a facsimile transmitter.

[Conventional technology]

Conventionally, many document reading apparatuses use an optical system to project and form a reduced image on a reading element array.

FIG. 4 shows the main part of one example, in which a document image is sequentially projected onto an array (not shown) of reading elements arranged in a one-dimensional direction and having a scanning function. As shown in the figure, an original illumination lamp 2 equipped with a reflective shade 1 and a first mirror 3 are integrally arranged (hereinafter referred to as a first mirror unit), and are connected to a second mirror 4 by wires 5a and 5b, respectively. The wires 5a and 5b are connected to rollers 6a and 6b and rollers 7a and 7, respectively.
b, is suspended between rollers 8a and 8b and rollers 9a and 9b. When the drive shaft 10 rotates, the first mirror units 2 and 3 and the second mirror 4 move along the guide sliding plate 12 in the Y direction. An original O (not shown in this figure, see FIGS. 1 and 2) is placed above the movement trajectory of the first mirror 3, and the original image is projected onto the photosensitive surface of the reading element by the reduction projection lens 10. imaged. The scanning function of the reading element performs main scanning (in the direction of arrow X), and the movement of the first mirror units 2 and 3 performs sub-scanning (in the direction of arrow Y).

In such a moving mechanism, the first mirror unit 2-3 and the second mirror 4 are only connected by the wires 5a and 5b, so the desired restraint relies on the tension of the wires 5a and 5b. . Therefore, in the direction of the arrow X, the first mirror units 2 and 3 and the second mirror 4 easily move in phase π by several liters. However, since the image is projected by the lens 10, the length of the mirrors 2 and 3 in the X direction is enough to cover the optical path locus of the lens 1O if it is about the width of the document. It's not a problem.

Nowadays, there are some systems in which the original image is projected onto a 1:1 reading element array without being reduced in size. An example in which the element array is moved by a mechanism similar to the moving mechanism described above is shown in FIG.

The l:l reading element array 14 has sliding members 16a and 16b.
is attached to. The sliding members 16a and 16b are respectively connected to wires 15a and 15b suspended between the respective pulleys, and placed on the guide sliding plate 12. Above the element array 14, an array 1 of short focus and small diameter lenses such as SELFOC (trade name) lenses is placed at a certain distance.
8 (not shown in this figure, see FIG. 1) is attached. Therefore, the element array 14 and the lens array 18 move integrally in the direction of the arrow Y.

Such a system uses a lens array 18 which is an imaging optical system.
Since the optical path length is short, the device can be miniaturized, which is convenient, but it also causes the following inconveniences. 1 of the reading element array 14
bit is one pixel of the original and l=1, for example, the resolution is lθ
If there is ~20 pel/m11, then 1 pixel or 1b
it is 0. IXo, 1 ma+2~0.05X0.05
■It becomes 2. On the other hand, since the reading element array 14 relies on the tension of the wires 15a and 15b to restrain it in the direction of the arrow X, it may easily move several inches, and even the slightest impact during operation will cause it to sway. As a result, the reading element array 14
1 bit and 1 pixel of the original. Compatible with 54ft<'□,
For example, there is an inconvenience when one straight line is read as a curve and three lines are read.

[Problem that the invention seeks to solve]

The present invention aims to eliminate the above-mentioned drawbacks of conventional devices and provide a document reading device that can perform accurate reading.

[Means for solving problems]

1; In order to solve this problem, the present invention provides a document reading method in which scanning is performed using reading elements arranged in a one-dimensional direction, and sub-scanning is performed by driving the reading elements in a direction that intersects with the one-dimensional direction. In the apparatus, the moving member to which the reading element is attached is elastically supported so as to be slidable from one direction in the one-dimensional direction and rigidly supported so as to be slidable from the other direction with respect to the guide member that guides the movement. , the above-mentioned movement is performed.

[For production]

Since such means are adopted, the reading element moves in the sub-scanning direction without wobbling in the main-scanning direction.

(Embodiment) Fig. 1 is a longitudinal cross-sectional view of an embodiment of a document reading device to which the present invention is applied, and Fig. 2 is a cross-sectional view thereof.In these figures, a book document 0 to be read is placed on the document platen glass. Board 20
It is located in Itl. The document illumination lamp 2 illuminates the image surface of the document 0, and the reflected light is imaged on the light receiving surface of the reading element array 14 by the imaging lens array 18. Reflector shade 1/document illumination lamp 2-imaging lens array 1
8. The reading element arrays 14 are each attached to a movable table 22. As shown in FIG. 3, the lower surface of the moving table 22 has sliding members 23a, 23b and 23 whose lower sides are sliding surfaces.
c and 23d, and are placed on guide rails 25a and 25b, respectively, which are fixed to the main body of the device. Furthermore, a sliding member 27 that contacts the side surface of the guide rail 25a is fixed to the movable table 22, and a sliding member 28 that faces the sliding member 27 and sandwiches the guide rail 25a is an elastic mounting member 29. installed. Note that a leaf spring, a rubber plate, or the like can be used as the elastic mounting member 29. Sliding member 23a*23
For b*23c*23d*27*28, a wear-resistant and low-friction material such as ultra-high molecular weight polyethylene is used.

The movable table 22 is connected to wires 15a and 15b, and each wire 15a and 15b is suspended by drive pulleys 32a and 32b and driven pulleys 33a and 33b, respectively (see FIG. 5). A drive shaft 34 to which drive pulleys 32a and 32b are attached is connected to a motor 35 by a belt 36.

With the above configuration, when the motor 35 rotates, the moving table 22 moves in the direction of arrow Y along the guide rails 25a and 25b.

That is, sub-scanning is performed by the original illumination lamp 2e, the imaging lens array 18, and the reading element array 14. At this time, since the guide rail 25a is sandwiched between the sliding members 27 and 28, it does not swing in the direction of arrow X, that is, in the main scanning direction.

〔Effect of the invention〕

As explained above, in the document reading device of the present invention, since the reading element moves in the sub-scanning direction without wobbling in the main-scanning direction, there is no misreading of a straight line as a curved line, and extremely accurate reading is possible. becomes.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of a document reading device to which the present invention is applied, FIG. 2 is a cross-sectional view thereof, FIG. 3 is a perspective view of the main part thereof, and FIGS. FIG. 2 is a perspective view of essential parts of the reading device. 0 is a document, 2 is a document illumination lamp, 14 is a reading element array, 18 is an imaging lens array, 15a*15b is a wire,
22 is a moving table, 23a*23be23c/23d-27
-28 is a sliding member, 29 is an elastic mounting member, 32a-32
33a-33b are pulleys, 35 is a motor, X is the main scanning direction, and Y is the sub-scanning direction.

Claims (1)

[Claims] 1. In a document reading device that performs main scanning with reading elements arranged in a one-dimensional direction and performs sub-scanning by moving the reading elements in a direction intersecting the one-dimensional direction, a guide member that guides the movement is provided. On the other hand, the moving member to which the reading element is attached,
A document reading device characterized in that the document reading device is elastically supported so as to be slidable from one direction in the one-dimensional direction, and rigidly supported so as to be slidable from the other direction to cause the movement.