JPH0434537A - Optical device of image forming device - Google Patents

Abstract

PURPOSE:To enable a lens part and a mirror part to move mutually without their interference on their common guide shaft by stopping one of the lens part and mirror pat from moving when the gap between the lens part and mirror part becomes less than a specific value and moving the other in such a direction that the gap becomes large. CONSTITUTION:Timing belts 62 and 63 are driven independently by the rotations of motors 66 and 67 to rotate, the lens part 53 and mirror part 54 move under the guidance of the guide shaft 52, and a lens 70 and a mirror 71 move indepen dently to specific positions to adjust copy magnification. At this time, the initial positions of the lens part 53 and mirror part 54 are detected and pulses of a pulse motor 66 are counted to calculate the position of the lens part 53 continu ously. The gap between bushes 57b and 58b is calculated from the calculated value and the pulse motor 66 is stopped from rotating when the lens part is moved to below a specific position. At the same time, a pulse motor 67 is rotat ed to move the mirror part 54 in the leaving direction. Consequently, the converted quantity of th copying magnification is maximum, interference on the common guide means is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an optical device that is provided in an image forming apparatus such as an electronic copying machine and that adjusts the copying magnification.

(Prior Art) An electronic copying machine is provided with an optical device that includes a lens section, a mirror section, etc. and adjusts the copying magnification.

Conventionally, these lens portions and mirror portions have been guided by guide shafts that are dedicated guide means, respectively, and driven to travel by pulse motors that are drive means. Then, the copying magnification is adjusted by moving the lens section and the mirror section to predetermined positions, respectively.

(Problems to be Solved by the Invention) As described above, in the conventional optical device for adjusting copying magnification, the lens portion and the mirror portion are each guided by a dedicated guide shaft and driven to travel. The guide shafts and the sliding bushes provided on each mirror part did not interfere with each other.

However, there are problems in that two guide shafts are required, the number of parts increases, and the space required also increases.

On the other hand, if a single guide shaft is used in common, depending on the arrangement of optical elements, the spacing between bushes, the adjustment range of copying magnification, etc.
There was a problem in that the bushings on the lens part and the bushings on the mirror part interfered.

The present invention has been made in view of the above points, and is intended to prevent interference between the bushings provided on each when the lens portion and the mirror portion are slidably mounted on the same guide member and driven to travel. An object of the present invention is to provide an optical device for an image forming apparatus that can perform the following steps.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention has a lens part and a mirror part that travel independently guided by the same guide means, and the lens part and the mirror part An optical device for an image forming apparatus that adjusts copy magnification by independently moving the lens section and the mirror section, the optical device comprising: a driving means for independently moving the lens section and the mirror section; a detection means for detecting that one of them has moved and the distance from the other has become less than a predetermined value; and a signal detected by the detection means to stop the movement of the one and move the other in a direction away from the one. The present invention is characterized by comprising a control means for controlling the driving means as shown in FIG.

(Function) According to the above configuration, by moving the lens section and the mirror section alternately while avoiding interference, interference can be prevented from occurring on the common guide means even when the amount of conversion of copy magnification is maximum. can.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing the configuration of an optical device according to this embodiment;
FIG. 2 is a sectional view showing the overall configuration of an electronic copying machine to which the optical device is applied.

The electronic copying machine shown in FIG. 2 includes a copying machine main body 1 having a document table 2 made of transparent glass fixed to the top surface, and an original document rotatably supported at one end on the top surface of the main body 1 and covering the top surface of the document table 2. A cover 3, upper and lower paper feed cassettes 4.5 that are removably loaded on one side of the main body 1 and protrude from the negative side, and a paper feed cassette 4.5 that protrudes from the paper discharge end of the other side of the main body 1. It consists of a tray 6.

Inside the main body 1, there is an optical system consisting of an exposure lamp 7 and a mirror 8, 9, and 10 that move back and forth in the direction of arrow a along the lower surface of the document table 2, and an optical system that uses reflected light from exposure scanning of the optical system to change magnification. A photoreceptor drum 13 that forms an image through a lens block 11 and a mirror 12, a developer 14 that applies toner to an electrostatic latent image formed on the surface of the photoreceptor drum 13 to make it visible, and a photoreceptor drum. The copy paper P stored in the cassette 4 or 5 is rotated in synchronization with the rotation shown by the arrow C in 13.
A transfer charger 20 and a peeling charger 21 are connected through the delivery roller mechanism 15 or 16 and the guide path 17 or 18.
The toner image is transferred via a registration roller pair 22 that brings the copy paper P into close contact with the surface of the photoreceptor drum 13 and a transfer charger 20, and the copy paper P is separated from the drum 13 by a peeling charger 21. A pair of fixing rollers 24 provided at the end of the conveyor belt 23 to fix the toner image onto the copy paper P, and a pair of paper ejecting rollers 25 provided adjacent to the pair of fixing rollers 24. Paper P
is discharged onto the tray 6 via this pair of rollers 25.

Further, on the peripheral edge of the photoreceptor drum 23, a charger 26 for removing electricity is provided along the rotational direction to remove electricity from the drum 13 after transfer.
A cleaner 27 removes the toner adhering to the surface of the drum 13 after static electricity has been removed, a static elimination lamp 28 erases the residual image on the drum 13, and the surface of the photosensitive drum 13 is charged to form an electrostatic latent image during exposure. Charger 2 for imaging
9 is placed.

Furthermore, there is a cooling fan 30 in the main body 1 to prevent temperature rise, and a cooling fan 30 located at the insertion tip of the cassette 4.5.
Cassette size detector 31 consisting of a plurality of microswitch groups for detecting cassette size. ．． 32 etc. are provided.

In the above device, the lens block 11 for variable magnification is the first
This is an optical device according to the present embodiment shown in the figure.

In FIG. 1, a guide shaft 52 is fixed in parallel to one side within a box-shaped frame 51, and a lens portion 53 and a mirror portion 54 are attached to the guide shaft 52, respectively, and a pair of arms 55a are attached to the guide shaft 52.
, 55b and 56a, 56b so as to be slidable in the axial direction.

The arms 55a, 55b and 56a, 56b have bushings 57a, 57b, and 58 that slide on the guide shaft 52, respectively.
a and 58b are provided. Further, arms 55a and 55b attached to the lens section 53 are provided on both sides of the lens section 53, and arms 56g and 56b attached to the mirror section 54 are located outside the arms 55a and 55b.

The lens section 53 is connected to the arm 568.5 of the mirror section 54.
It is relatively movable between 6b.

Further, on one side of the frame 51, support shafts 59, 60, 61. are each rotatably attached. Timing belts 62 and 63 are stretched between the support shafts 59 and 60, and between 60 and 61, respectively, via boots (not shown), and the tips of arms 55a and 56b are fixed to the timing belts 6263, respectively. ing. Furthermore, driven gears 64 and 65 are fixed to the support shafts 59 and 61, respectively.
．． 65 is a step motor 6 fixed to the frame 51.
The drive gears 68 and 69 of 6.67 are in mesh with each other.

With the above configuration, the rotation of the motors 66 and 67 causes the drive gears 6g and 69 and the driven gear 6465 to
Timing belts 62, 63 are driven to rotate independently of each other. As a result, the lens section 53 and the mirror section 54 move guided by the guide shaft 52, and the lens 7o provided on the lens section 53 and the mirror 71 provided on the mirror section 54 move independently to predetermined positions. The copy magnification is adjusted accordingly.

Next, a method of driving the lens section 53 and mirror section 54 will be explained with reference to FIG. 3. (a) and (c) show the positional relationship between the lens section 53 and the mirror section 54 at copying magnifications of 122% and 65%, respectively. When moving the lens section 53 and mirror section 54 from the state shown in (a) to the state shown in (C), first the lens section 53 is moved to the position shown in (b).

At this time, the lens portion 53 is
By detecting the initial position of the mirror section 54 and counting the number of pulses of the pulse motor 66 after the lens section 53 starts moving, the lens section 53 is continuously moved.
Calculate the position of

Based on this calculated value, the distance between the bushes 57b and 58b is calculated, and when a detection means (not shown) detects that this distance has become less than a predetermined value, the rotation of the pulse motor 66 is stopped. At the same time, the rotation of the pulse motor 67 is started and the mirror section 54 is moved to the predetermined position shown in (c).

After that, the pulse motor 66 is rotated to move the lens portion 53 (
Move to the predetermined position shown in C) to complete the setting of the copy magnification of 65%.

The above control is performed by a control means (not shown) built into the electronic copying machine.

FIG. 4 shows a flow diagram of the operation when copying is performed by changing the copying magnification using the optical apparatus according to this embodiment.

In step (a), when the initial conditions of each part are set, in step (b), the LED on the operation panel lights up in green. Next, in step (C), when the magnification setting key is pressed to change the copy magnification, step (d)
The LED lights up in red. If the magnification is not changed, check whether the manual feed switch is ON in step (e), and if it is ON, press the Stereo knob (f) and press the print key. Copying processing is performed in step (g). If the manual feed switch is ON, copy processing is immediately performed in step (g). If the print key has not been pressed, the process returns to step (b).

When the LED turns red in step (d), the pulse motor 66 on the lens side starts rotating in step (h). Next, in step (i), when the number of pulses of the pulse motor 66 matches predetermined copying magnification data, the rotation of the pulse motor 66 is stopped. If they do not match, in step (j), the lens portion 53 and the mirror portion 54 are alternately moved to move the lens portion 53 to a predetermined position. Next, in step (k), the step motor 67 on the mirror side is rotated, and step <
In step 11), it is confirmed whether the mirror portion 54 has finally moved to a predetermined position.

If YES, proceed to step (f); if NO, return to step (j).

According to this embodiment, interference between the bushes 57b and 58b of the lens section 53 and the mirror section 54 can be prevented, and the lenses can be moved on the common guide shaft 52. In addition, bushings 5 provided on the lens portion 53 and the mirror portion 54, respectively.
It is possible to increase the distances between 7a and 57b and between 58a and 58b, which makes it possible to reduce the deviation of the optical axis compared to when these distances are small, and at the same time to reduce the movement of the lens section 53 and mirror section 54. It can be done smoothly.

In the above embodiment, the lens-side bushings 57a and 57b are both located between the mirror-side bushings 58a and 58b, but as shown in FIG.
a and 57b may both be located outside the bushes 58a and 58b, or only the bushing 57b may be located between the bushes 58a and 58b as shown in FIG.

〔Effect of the invention〕

As explained above, according to the present invention, when the distance between the lens section and the mirror section becomes equal to or less than a predetermined value, the movement of one is stopped and the other is moved in the direction in which the distance becomes larger. The lens section and the mirror section can be moved relative to each other on a common guide axis while preventing interference. Further, the lens section and the mirror section can be moved stably, and space can be saved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the configuration of an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the overall configuration of an electronic copying machine to which the optical device according to the embodiment is applied, and FIG. FIG. 4 is a flowchart, and FIGS. 5 and 6 are plan views showing other embodiments of the present invention. 52...Guide means (guide shaft) 53...Lens section 54...Mirror section 66.67...Drive means (pulse motor) 52/Guide means (guide shaft) 53...Lens section 54/Mirror section

Claims (1)

[Scope of Claims] It has a lens section and a mirror section that move independently guided by the same guide means, and the copying magnification is adjusted by moving the lens section and the mirror section independently. An optical device of an image forming apparatus, comprising: a drive means for independently moving the lens section and the mirror section; and a driving means for moving the lens section and the mirror section so that the distance between the lens section and the mirror section is a predetermined value. and a control means that controls the drive means to stop the movement of the one and move the other in a direction away from the one in response to a signal detected by the detection means. An optical device for an image forming apparatus, characterized in that: