JP2618508B2 - Image reading device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus, and more particularly, to an image reading apparatus having both functions of image reading by a scanning optical system and fixed image reading. .

2. Description of the Related Art Conventionally, an image reading apparatus in an image forming apparatus scans a fixed original with a first mirror, which is an image reading unit, at a speed n, and scans a second third mirror at a speed n / 2. By maintaining the optical path length at a constant length, a scanning optical system that forms an image on the image carrier, and fixing the document reading unit and feeding the document at a fixed speed n over the fixed document reading unit, There is an original moving type in which images are sequentially formed on an image carrier.

In the case of the original moving type, there is no need to control the operation of the optical system having a large inertia, and the speed can be increased, and the original is longer than the platen glass, for example, an original such as computer format paper can be sent. There are advantages. However, in a high-speed copying machine that requires a large amount of light for reading a document, there is a disadvantage that one portion of the glass surface becomes excessively hot due to the heat generated by the illumination lamp. Was.

As a countermeasure, in addition to the scanning optical system, an illumination lamp dedicated to document movement and a retractable document reading mirror that is fixed to move are used. When the document moves, the fixed mirror rises and enters between the third and fourth mirrors. There is a proposal to read an image.

[Problem to be Solved by the Invention] However, in the configuration as described above,
Since the fixed mirror is within the moving range of the third mirror, if the scanning optical system scans while the fixed mirror is raised due to a software problem or the like, the third mirror and the fixed mirror collide, and the mirror is damaged. There is a problem of inviting.

The present invention is intended to solve such a problem. That is, an object of the present invention is to provide an image reading position in which collision between mirrors is avoided by providing means for restricting the movement of the fixed mirror and the scanning optical system.

[Means for Solving the Problems] A configuration for achieving the above object is a document table, a first mirror unit that moves in parallel with the document table, and moves at half the speed of the first mirror unit. A second mirror unit, and a transport unit that transports the original to the platen, and a fixed original reading function of reading the original fixed to the platen while moving the first and second mirror units; In an image reading apparatus having a moving document reading function for fixing the first and second mirror units at predetermined positions and reading a moving document by a transporting means, when the fixed document is read, the first and second mirror units move. A mirror that is retracted from the area and reflects image light of the moving original into the moving area of the second mirror unit at the time of reading the moving original to the light receiving portion; Regulating means for restricting entry of the mirror into the moving area of the second mirror unit when reading a fixed document, and restricting movement of the first and second mirror units when reading a moving document. .

[Operation] In the configuration described above, the first document is read at the time of reading a fixed document.
And the mirror which is retracted from the moving area of the second mirror unit and which enters the moving area of the second mirror unit at the time of reading the moving document and reflects the image light of the moving document to the light receiving portion when reading the fixed document. Since the entry of the second mirror unit into the moving area is restricted, and the movement of the first and second mirror units is restricted when reading the moving document, the second mirror is used for reading the moving document. Since the units do not collide, it is possible to prevent the device from being damaged even if a malfunction occurs.

[Embodiment] Figs. 1 and 2 show a first embodiment of the present invention, Figs. 3 and 4 show the same second embodiment, and Fig. 5 shows a rear side of the scanning optical system. ing.

First, in FIG. 1, 1 is a copying machine, 2 is an image forming unit, and 3 is a main body. That is, the copying machine 1 has a main body 3 having a built-in image forming unit, and the main body 3 includes a platen 5, a light source 6, a first mirror 7, a second mirror 8, a third mirror 9, a fourth mirror 10, Computer form feeder (CF
F) A mirror 11, a lens 12, a photosensitive drum 13, and the like are provided. The light source 6 and the first mirror 7 are on the first mirror base 14, and the second mirror 8 and the third mirror 9 are on the second mirror base 15
Above, the first mirror base 14 and the second mirror base 15 are collectively referred to as a scanning optical system. This scanning optical system usually has a home position at a position several to several tens of millimeters from the left end of the platen 5, and scans rightward from that position.

A computer form feeder (CFF) 100 and a document feeder (not shown) are provided above the main body 3, and are selectively used depending on a document to be used. CFF100
There is a window 19 on the left side of the platen 5 below
The CFF mirror 11 is located below the window 19.

When reading a normal original, the original is placed on the platen 5 by an operator's hand or by an automatic document feeder.
The document surface is placed on top, and the light source 6 and the first mirror table 14 on which the first mirror 7 is mounted scan the original surface to read an image. Along with this, the second mirror base 15 on which the second mirror 8 and the third mirror 9 are mounted moves at half the speed of the first mirror base 14 while keeping the optical path length constant, and the image is displayed on the first mirror base. The image is formed on the photosensitive drum 13 via 7 → second mirror 8 → third mirror 9 → lens 12 → fourth mirror 10. The first mirror base 14 and the second mirror base 15 are driven by a motor 16 shown in FIG.

Here, when reading a long original such as computer format paper, the original is set on the CFF100. this
When the detection sensor 103 detects that a document is set on the CFF 100, the first mirror base 14 and the second mirror base 15
Evacuate to the left as shown. Thereafter, the CFF mirror 11 moves to an angle of about 45 ° with respect to the optical axis L.

This mechanism may be performed by a solenoid 20 and a link mechanism, as shown in FIG. 2, or may be performed in several ways, such as by rotation by a motor.

Here, the distance between the CFF platen 105, which is the exposure unit on the CFF side, and the CFF mirror 11 is determined by the optical path length from the lens 12 to the original on the platen 5 via each of the mirrors 8, 9, 7 and the lens 12, CFF It is configured at a position where the optical path lengths through mirror 11 and window 19 to CFF platen 105 are equal, and CFF platen 1
A lamp 106 is arranged below 05. CFF mirror 11
Is raised, the document is transported onto the CFF platen 105,
An image is read while passing over the exposure position. The read image is formed on the photosensitive drum 13 via the window 19 → the CFF mirror 11 → the lens 12 → the fourth mirror 10.

Here, a switch 17 is mounted below the CFF mirror 11, as shown in FIG. 2, so that the CFF mirror 11 is in the home position (the third mirror 9 shown by a broken line in FIG. 1).
ON state only outside the range of movement). This switch 17 is in the power circuit of the motor 16,
That is, the first mirror base 14 and the second mirror base 15 are CFF
When the mirror 11 is not at the home position, it cannot move.

A switch 18 is attached to the retracted position of the second mirror base 15, so that it is turned ON only when the second mirror base 15 is at the retracted position. This switch 18 is in the power supply circuit of the solenoid 20, that is, the CFF mirror 11
Is such that it cannot stand up when the second mirror base 15 is not in the retracted position.

With such a configuration, for example, scanning of the scanning optical system and CFF
Even if the upright signal of the mirror 11 is issued at the same time, since the power supply circuit of at least one of the driving sources is opened by a physical method, no collision between the third mirror 9 and the CFF mirror 11 can occur, and The worst case of the damage of the can be avoided.

Next, in the case of FIG. 3, the lever 21 is attached to the CFF mirror 11, and is interlocked with the locking member 22 via a wire. The locking member 22 is the second mirror base 15
When the CFF mirror 11 is in the retracted position, it engages with the hole of the second mirror base 15 in conjunction with the erecting of the CFF mirror 11 to restrict the movement of the second mirror base 15. However, as shown in FIG.
When the second mirror base 15 is not at the retracted position, the shutter member 23 moves to the right by the force of the spring, and the position of the hole shifts, so that the locking member 22 cannot move upward. 11 can no longer stand.

Thus, when the second mirror base 15 is not at the retracted position, the CFF mirror 11 cannot stand up, and when the CFF mirror 11 is not at the home position, the second mirror base 15 cannot scan.

[Effects of the Invention] As described above, according to the present invention, when reading a fixed document, the first and second mirror units are retracted from the moving area, and when reading a moving document, the second mirror unit is retracted.
The mirror that enters the moving area of the mirror unit and reflects the image light of the moving document to the light receiving portion is restricted from moving into the moving area of the second mirror unit when reading a fixed document, and the mirror is not movable when reading the moving document. Since the movement of the first and second mirror units is regulated, the second mirror unit does not collide with the mirror used when reading the moving document, so that even if a malfunction occurs, the device is not damaged. Can be.

[Brief description of the drawings]

The drawings show an embodiment of the present invention, and FIG.
FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3 is an enlarged sectional view of one state of the second embodiment, FIG. 4 is an enlarged sectional view of another state of FIG. FIG. 5 is a rear perspective view of the scanning optical system. DESCRIPTION OF SYMBOLS 1 ... Copy machine, 2 ... Body 7 ... 1st mirror, 8 ... 2nd mirror 9 ... 3rd mirror, 10 ... 4th mirror 11 ... CFF mirror, 14 ... 1st mirror stand 15 ...... Second mirror base 17,18 Switch 21 Lever 22, Locking member 23 Shutter member

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiromitsu Goto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-59-208976 (JP, A) JP-A-55 -113067 (JP, A)

Claims (1)

(57) [Claims] An original platen; a first mirror unit that moves parallel to the original platen; a second mirror unit that moves at half the speed of the first mirror unit; Transport means for transporting, a fixed document reading function for reading a document fixed to the document table while moving the first and second mirror units, and the first and second mirror units at predetermined positions. An image reading apparatus having a moving document reading function for reading a document which is being moved by a fixed transporting means, wherein when reading a fixed document, the image reading apparatus is retracted from a moving area of the first and second mirror units, and when reading a moving document, A mirror for entering the moving area of the second mirror unit and reflecting the image light of the moving document to the light receiving portion; An image reading apparatus, comprising: a control unit that controls entry of a mirror unit into a moving area and controls movement of the first and second mirror units when reading a moving document.