JPS62276533A - Copying device - Google Patents

Abstract

PURPOSE:To make the space around a developing device wider without changing the external shape of a copying machine, by changing the arrangement of a scanning optical system. CONSTITUTION:A 1st mirror 1 and a 2nd mirror unit 2 provided with a right angle which returns an incident luminous flux from the 1st mirror in the direction opposite to a scanning direction S are set in such a way that the 2nd mirror unit 2 is put in the scanning direction S when it is viewed from the 1st mirror 1 and they are separated from each other by a distance (d) in the scan starting state and contacted with each other when the scan is completed. Therefore, the 3rd mirror unit 3 which receives the luminous flux reflected by the 2nd mirror unit 2 is opposite to a developing device 7 and the reflecting optical path from the 3rd mirror unit 3 to the 4th mirror 4 is not formed on the developing device 7. Therefore, the space above the developing device 7 can be widened.

Description

DETAILED DESCRIPTION OF THE INVENTION A. OBJECTS OF THE INVENTION [Industrial Application Field] The present invention relates in particular to the arrangement of a scanning optical system in a copying apparatus of a fixed document table type.

[Conventional technology]

A conventional scanning optical system of this type is shown in FIG. That is, first, before scanning, the first mirror 1 is moved close to the document setting reference position point A, and the reflected light beam is returned to the direction opposite to the scanning direction S to the second mirror unit 2 provided at the scanning start point (home position) point B. The light beam reflected in the scanning direction from the second mirror unit 2 passes through the lens system 5,
The light is projected onto the photoreceptor 13 via a third mirror unit 3 disposed immediately near the scanning end point C and a fourth mirror 4 that receives the reflected light beam.

[Problem that the invention seeks to solve]

In such a configuration, from the manuscript surface 11 to Renzobu 5/711, 17.
In order to equalize the optical path lengths up to 3, the third mirror unit 3 is mostly arranged closer to the scanning direction than the developing device 7. Therefore, if you try to increase the capacity of the developing device 7, the third
There was a drawback that the light flux from the mirror unit 3 to the fourth mirror 4 was obstructed. To prevent this, conventionally, the fourth
This problem has been solved by increasing the distance between the mirror 4 and the photosensitive drum 13. However, this method has the disadvantage that the increased capacity of the developing device 7 increases the size of the copying machine and increases the cost.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to widen the space around the developing device by changing the arrangement of the scanning optical system without changing the external shape of the copying machine.

However, when enlarging, the first mirror 1 and the second mirror unit 2 generally move by the reciprocal of the magnification, with the first mirror 1 moving at a speed of 2, while the second mirror unit 2 moves at a speed of 1. Scan as if moving. At the same time, the lens system 5 also moves toward the second mirror unit to determine the magnification.

For this reason, if we use the younger brother 3 measurement point as the scanning end point during enlargement,
In the configuration shown in Fig. 3, when enlarging, the first mirror 1 is placed at the scanning end point.
As a result, the lens system 5 was able to move a large distance without hitting the second mirror unit 2, and a sufficient magnification ratio could be achieved.

However, in the configuration of the present invention described above, the lens system 5 at the same magnification position
When attempting to enlarge the amount of movement of the mirror, a disadvantage arises in that a large enlargement ratio cannot be achieved due to the relationship with the second mirror unit.

The second invention aims to solve the above problems of the first invention.

Structure of the Invention [Means for Solving Problems] The t51st invention is a copying machine with a fixed manuscript table, in which a right angle is set to return the incident light beam from the first mirror 1 in the opposite direction to the scanning direction S. A second mirror unit I and a second mirror unit 2 having the same are placed in the scanning direction S when viewed from the first mirror 1, and a distance d is separated between the first mirror 1 and the second mirror unit 2 in the scanning start state,
This copying apparatus is characterized in that it has a scanning optical system in which the first mirror and the second unit are in contact with each other when scanning is completed.

A second invention is a copying apparatus according to the first invention, in which the document setting reference position is provided on both sides A-AI of the document table.

[For production]

The first invention is to direct the reflected light beam from the first mirror 1 that receives the image light in the scanning direction S, contrary to the conventional method in which it is directed in the opposite direction to the scanning direction S, so that the reflected light beam from the second mirror unit 2 can be reflected from the second mirror unit 2. The third mirror unit 3 receives the reflected light flux of
It is arranged on the side of the set reference position ZtA of the document opposite to the position of the developing device 7, and therefore the reflected optical path from the third mirror unit 3 to the fourth mirror 4 is not formed above the developing device 7.
The above problems are solved.

The second invention is that in the optical system of the above invention, when enlarging, the first mirror 1 is set by setting the reference position of the document at point A1 (substantially the same as the scanning end point C at the same magnification). Since it is retreated in the scanning direction from just below the edge A of the original to B', the optical path necessary for enlargement can be secured.

〔Example〕

FIG. 1 shows an embodiment of the present invention, in which a first mirror 1 is installed directly below the document installation reference point A to send the light beam from the document in the scanning direction. A second mirror unit 2 having a right-angled fold with a home position B is installed on the S side, and reflects the light beam from the first mirror 1 in a direction opposite to the scanning direction S.

At this time, the first mirror 1 and the second mirror unit 2 are in a state where the mirror interval d is large apart from each other in the state (standby state) before starting scanning, and after the start of scanning, each mirror is set to the first mirror 1 moves at a speed of 2 together with the document irradiation light source 6, while the second mirror unit 2 performs scanning so as to move at a speed of 1. As a result, at the scanning end point C, the distance d between the first mirror 1 and the second mirror unit 2
As shown by the dotted line, in addition to the above-mentioned optical system approaching (closing together), the light flux from the document surface received by the second mirror unit 2 is on the side opposite to the scanning direction S when viewed from the second mirror unit 2. The photoreceptor 13 is guided to a third mirror unit 3 (having a right-angled fold) installed at the top of the photoreceptor 13, further guided in the scanning direction by the third mirror unit 3, and bent by a fourth mirror 4 installed above the photoreceptor 13. The third mirror unit 3 is connected to the developing device 7 so that an image is formed on the surface of the photoreceptor 13 by
and install it in the opposite direction. The developing device 7 is installed beside the direction in which the photoreceptor drum 13 rotates (clockwise rotation in the illustrated example).

The drawing shows transfer charger 8-cleaner 9/electrostatic charger 1
Although an electrophotographic copying machine equipped with a 0ψ-order charger 12, a fixing device 14, etc. is exemplified, the present invention is applicable to other electrostatic recording devices.

C. Effects of the Invention The first invention is such that the reflected optical path of the third mirror unit 3, which forms an image on the photoreceptor from the third mirror unit 3 via the fourth mirror 4, does not pass over the developing device 7. Since the scanning optical system is constructed in this way, it is possible to make the space above the developing device 7 wider, and therefore, it is possible to increase the capacity of the developing device while maintaining a compact size without changing the external shape of the copying machine.

This made it possible to reduce the cost per copy.

Further, if the document setting reference position is A and the position of the lens system 5 is E, the position of the second mirror unit 2 is determined to be B, and the movable range of the lens system 5 is between EB and the magnification ratio when changing the magnification. However, by setting the document setting reference position to A1 according to the second invention, the position of the second mirror unit 2 is moved back to position B in the scanning direction.
Changes to As a result, the movable range of the lens system 5 becomes between EB and it becomes possible to increase the magnification ratio.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an optical system showing an embodiment of a copying apparatus according to the first invention, FIG. 2 is a block diagram of the second invention, and FIG. 3 is a block diagram of a conventional optical system. DESCRIPTION OF SYMBOLS 1... 1st reflective mirror, 2... 2nd mirror unit, 3... 3rd mirror unit, 4... 4th mirror,
5... Lens system, 7... Developing device, 13... Photosensitive drum, S... Scanning direction, A-AI... Document setting reference position, B-B... Scanning start point, C...Scanning end position, d...Distance between the 10th and 2nd mirrors. Figure 2 Figure 3 Figure 1

Claims (2)

[Claims] (1) In a copying machine with a fixed document table, a second mirror unit having a right angle that returns the incident light beam from the first mirror in the opposite direction to the scanning direction is placed in the scanning direction when viewed from the first mirror, and scanning is started. 1. A copying apparatus comprising a scanning optical system in which a first mirror and a second mirror unit are separated from each other in this state, and the first mirror and second mirror unit are brought together at the end of scanning. (2) In a copying machine with a fixed document table, a second mirror unit having a right angle that returns the incident light beam from the first mirror in the opposite direction to the scanning direction is placed in the scanning direction when viewed from the first mirror, and scanning is started. constitute a scanning optical system in which the first mirror and the second mirror unit are separated from each other in the state of , and the first mirror and the second mirror unit are brought together at the end of scanning,
A copying apparatus characterized in that document setting reference positions are provided on both sides of the document table.