JPS6315566A - Picture reader - Google Patents

Abstract

PURPOSE:To read pictures of both sides by unidirectional carrying only by reading the picture of the 1st side of a document at the 1st position of an original platen, leading the picture on a 2nd side at 2nd position to the 1st position through the use of an optical system and reading it. CONSTITUTION:A stripe zone A is set on the original platen 10, and when the original 20 passes through the zone A, the picture of the original 20 is formed on a read member 17 via an image forming lens 16 sequentially to read the picture. When the reading of the original 20 at the zone A is finished, the tip of the original 20 is located at a zone B as a 2nd zone apart from a zone A by a distance (f) in the carrying direction. Then the picture of the original 20 radiated at a zone B is led to the zone A by mirrors 21, 22 being the optical system provided above the original 20, the picture on the opposite side to the original platen 10 is led to the image forming lens 16 and the image is formed to the read member 17.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image reading device that optically reads both the front and back sides of a document.

(Prior Art) Conventionally, in an image reading device that automatically reads images on both the front and back sides of this type of document, the document is guided from the document supply device to the document table, and the document that has been read by −.degree. The document is turned over after going through the i-path and process, and then guided to the document table again, and then the opposite side (back side) is read.

(Problems to be solved by the invention) However, in the case of such a conventional example, since the document must be turned over, the turning operation takes time, and not only is it impossible to perform a high-speed reading operation, but also a complicated reading operation is required. There are problems in that the document may be damaged or jammed in the process of operation.

Therefore, the present invention has been made to solve the above-mentioned problems of the conventional example, and its purpose is to transfer images on both sides of a document at high speed by simply transporting the document in one direction without turning it over. An object of the present invention is to provide an image reading device capable of reading images without causing congestion.

(Means for Solving the Problems) In order to achieve the object L, the present invention includes a transport means for transporting the original in one direction, and a transport means for transporting the original by the transport stage a reading means for sequentially reading images of a first side of the original at a first position on the upper side; and a reading means for transporting the original and reading an image of a second side of the original at a second position of the original table. and an optical system that guides the image of the second surface from the second position to the first position for reading.

(Function) In the present invention having the configuration described in L, the document is transferred in one direction by the transfer means, and the document is transferred to the first position on the document table, so that the reading device reads the first portion of the document. The image on the surface is read, and then the document is transported to a second position by the transport means, the image on the second surface of the document is guided to the first position by the optical system, and is read at the L reading stage f, This allows images on both sides to be read simply by moving in one direction.

(Example) Hereinafter, the present invention will be explained based on the illustrated example. 1st
The figure is a schematic configuration diagram showing a first embodiment of an image reading device according to the present invention. In the figure, 1O is a document table through which light can pass, and a document 20 is supplied to this document table 10. Ru. The original 20 is guided by a plurality of rollers 11, which serve as transport means, arranged on the original table 101- at predetermined intervals, and is transported in the direction of arrow X. Reference numeral 12 denotes a light source provided below the document table 1O, and the light source 12 illuminates the first position A from below the document table 10. Then, place document 2 in position A.
When the leading edge of 0 is located, the document 20 irradiated at position A
The image is taken from mirrors 13 and 1 disposed below the document table 10.
4.15, an image is formed by the imaging lens 16 on a reading member 17 as a reading means such as a photosensitive element r- of a CCD (charge coupling 7-)':g or a photosensitive drum, and the image is read.

Here, the document reading system of the same embodiment is shown in FIG. 3(d).

To explain based on (b), the original 20 on the original platen 101 is transported in the direction of arrow X by the roller 11 as shown in (a) of the same figure. As shown in FIG. 1, a belt-shaped A position is set on the document table 10F, and when the document 20 passes through the A position,
As shown in FIG. 2(b), images of the original 20 at position A are sequentially focused on the reading member 17 via the imaging lens 16, and the first surface of the original 21, which is the surface on the original table lO side, is imaged. Read the image. In addition, in FIG. 3, the imaging lens 16 is
A mirror (illustrated in m1) that changes the optical path between these steps is omitted.

Further, if the distance from the position A to the imaging lens 16 is D, it can be expressed as distance@D=a+b+c+d. In FIG. 1, a is the distance from the mirror 15 to the imaging lens 16, b is the distance from the mirror 14 to the mirror 15, c is the distance from the mirror 13 to the mirror 14,
d is the distance from the A position to the mirror 13, e is the distance from the mirror 22
The distance is from A to 1°6. - On the other hand, if the transport distance of the original 2o is f, then when the reading of the original 2o at the A position is completed r, the leading edge of the original 2o is moved to a second position a distance fif away from the A position in the moving direction. It is at position B.

Reference numeral 18 denotes a light source that irradiates the original 20 at the B position from the −L direction, and the image of the original 20 irradiated at the B position is captured by mirrors 21 and 22, which are optical systems disposed below the original 2o. The image of the second surface, which is the image of the surface opposite to the document table 10, is guided to the imaging lens 16 through the same path as above, and is imaged on the reading member 17. be done. Here, the brightness ratio of the light sources 12 and 18 is the same -
Adjustment is made in advance so that the same image is input to the reading member 17 for the m- original. Further, assuming that the positions of the imaging lens 16 and the reading member 17 remain unchanged, unless the distance #D' from the image position B to the imaging lens 16 is made equal to the distance fiD, the reading member 17F must be is not imaged.

Therefore, at the same time that the reading of the original 20 moves from the A position to the B position, the route of the image from the B position to the imaging lens 16 is corrected so that the distance f2ID'=D. This is 1. For example, a control device composed of a CPU, ROM, and RAM supplies the document 2o to the manuscript table 10, and then
The time required to transport the original 20 to position B is calculated from the transport speed and the transport distance of the original 20, and the time after the original 20 is fed to the original platen 10 during the reading operation is measured.
A servo motor (not shown) is operated at the time when the document 20 reaches position B, and the power of the servo motor is transmitted to the mirror 14.15 by a wire, and the mirror 14.15 is shown as the first factor 14', At the 15' position, the distance ax (D'=a+b
+c+d+e+f+g-2x, x=-'-mu week LL)
move it. In addition, other than this, rme 14', 15'
Mirrors 14, 15 and other mirrors disposed near the position may be moved to positions 14' and 15' at the above-mentioned times in a manner similar to that described above.

In the above configuration, the operation of reading images on both sides of a document will be described with reference to FIGS. 2(a) and 2(b). Figure 2 (a) shows a state in which the image of the surface of the original document 20 on the document table 10 side is being read at position A, and Figure 2 (b) shows the state in which the image of the original 20 on the side of the original platen 10 is read at position A, and the image of the original 20 is read at position B. It shows a state jE in which reading begins on the side opposite to the table lO. Therefore, as shown in FIG. 2(b), the distance # between mirrors 21 and 22 is
By making f equal to the length of the original 20 in the transport direction, after reading one side of the original 20 r, the other side can be read immediately.

Here, the distance #if may be made variable; for example, the distance #if may be changed from
The device consists of PU, ROM, RAM, etc. The servo motor is operated at a constant speed for a certain period of time based on the document length, and the power of the servo motor is transferred to the mirror 2L using a wire, etc.
It is possible to equalize the distance f by transmitting the signal to the mirror 2l and moving the mirror 2l a certain distance. Furthermore, distance: a
Even if f is made longer than the length of the original 20, there is no problem with the function of reading images on both sides of the original 20. Also, in the above embodiments.

Even if the direction of transport of the document 20 is reversed, the same structure allows
It has a similar effect.

Next, an example in which the image reading device according to the present invention is applied to a copying machine will be explained based on FIGS. 4(a) to 4(c). Same figure (
As shown in a), the time from when the A4 size document 40 reaches the input position until it reaches the B position is tL. JIX draft 4
If the time from when 0 reaches 8th place 2 until it finishes passing through position B is ti, then the time 1+ as shown in the same figure (b)
, one image formed in one order of one construction can be obtained. This image is exposed to the photoreceptor drum inside the copying machine,
By printing through an electrophotographic process, it is possible to record and print images of double-sided spreads of a document using A2 size recording paper, which is twice the size of an A3 size document.

Further, FIG. 5(a) shows the second image reading device according to the present invention.
FIG. 2 is a schematic diagram of main parts showing an embodiment, in which a plurality of optical fibers 50 are arranged in parallel as an optical system, and the optical fibers 50
The ends of the images are placed at positions A and B, respectively, and the image at position B is
It is designed so that it can be guided to a certain position. That is, as shown in FIG. 5(a), the original e;
When the document 52 is transported and passes through the A position and the B position, both sides of the original 52 are sequentially guided to the A position similarly to the case where a mirror is used as an optical system as in the first embodiment. therefore,
By using the optical fiber 50 in the optical system, it is possible to eliminate the need for a mirror device, and also to flexibly determine the image transmission path, thereby making it possible to downsize the device.

(Effects of the Invention) The image reading device related to unissued IJI has the configuration and operation described below, and can read images on both sides of a document by simply transporting it in one direction without turning over the document once read. can. This eliminates the need for a process and mechanism for turning over the original, shortens the transport path for the original, and allows images to be read without congesting traffic than at high speeds.
This has the effect of reliably preventing damage to the original and occurrence of a jam.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of an image reading device related to unissued IJI, FIGS. 2(a) and (b) are schematic diagrams showing a document reading operation in the same embodiment, and FIG. 3 (a)
, (b) is a schematic perspective view showing the original reading system in the same embodiment, Figure II, and Figures 4 (a), (b), and (c) each show an example in which the present invention is applied to a copying machine. Explanatory drawings, FIGS. 5(a), 5(b), and 5(C) show a second embodiment of the image reading device related to Unreleased II, and IΔ(a) is a schematic diagram of the main part,
FIG. 5B is a schematic perspective view, and FIG. 1C is a cross-sectional view of the optical fiber. Explanation of symbols 1O...Original table 11...-R (transfer stage R)
Medical doctor 12.18...Light source 16...Imaging means
-17...Reading member (reading means) 20...Manuscript 21.22...Mirror (optical system) 50...Optical fiber (optical system) Patent issued by Canon Co., Ltd. Agent Patent attorney Yoshikazu Kamisuke -7 Agent Patent attorney
Back 1) Rules 7'-He, Figure 2, Figure 3 (a) (b) Figure 4, 1. 1゜Figure 5

Claims (3)

[Claims] (1) A transport means for transporting the original in one direction; a reading means for transporting the original by the transport means and sequentially reading images on the first side of the original at a first position on the original table; an optical system for guiding an image of the second surface of the document from the second position to the first position in order to read the image of the second surface of the document by the reading means at a second position on the document table; An image reading device comprising a system. (2) The image reading device according to claim 1, wherein the optical system includes a plurality of mirrors. (3) The image reading device according to claim 1, wherein the optical system is an optical fiber.