JPH0372973B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a driving device for a moving optical system used in a copying machine or the like, and more particularly to an improvement in an optical system driving device using a wire.

BACKGROUND ART A moving optical system including a movable mirror used in a copying machine or the like is driven by an optical system driving device.

Particularly in the case of slit exposure type copying machines, it is necessary to move the mirror and photoreceptor while keeping them parallel to the longitudinal direction of the slit in order to obtain distortion-free images with good focus magnification. .

These moving optical systems are configured to move back and forth on a mount by providing rollers at both ends, or by using a roller at one end and a guide at the other end. A pulley is provided at the end of the moving optical system on the guide side, and is driven by a wire stretched on one side of the pulley.

One-sided wire-driven optical system drive devices that drive the moving optical system by a wire stretched on one side do not require optical axis adjustment and are easy to set the wire tension. The problem is that the support member for supporting the device is large, making it difficult to reduce the size and weight of the device.

On the other hand, a double-sided wire drive system in which wires are stretched independently on both sides is advantageous in terms of size and weight reduction, but it is difficult to set the tension of each wire, balance the tension of both wires, and move the wires. There were difficulties in adjusting the balance of quantities, etc. FIGS. 1 and 2 show a drive system of an optical system drive device of a slit exposure type copying machine of a double-sided wire drive type. As it is clear from the figure, both have almost the same configuration, so the problems and the like will be explained below using FIG. 1. In the figure, reference numerals 1 and 2 are drive pulleys for driving mirror support members (M1 and M2 to be described later) provided on both sides in the longitudinal direction of the mirror and on one side in the moving direction of the mirror. etc., and is fixed to the drive shaft 3.

The drive shaft 3 is configured to be rotated forward and backward by a drive mechanism (not shown). Further, the second support member M2 that holds the second and third mirrors is integrally provided with moving pulleys 4 and 5 on one end side and moving pulleys 6 and 7 on the other end side. Furthermore, fixed pulleys 8 and 9 which are pivotally supported by the main frame are arranged on the opposite side of the drive pulleys 1 and 3 with respect to the moving direction of the mirror.

M1 is a first support member that holds a first mirror that is moved integrally with the exposure light source, and the first support member and the second support member have a ratio of 1:1/1 as is well known.
They are moved in the same direction with a speed ratio of 2.

Next, we will discuss how to wire the wire. At one end in the longitudinal direction of the support member, a wire 10a whose one end 12a is fixed to a frame is wound around the movable pulley 4 in a U-shape, and is fixed to the first mirror support member M1 at an intermediate position 14, and is driven. It is wound around pulley 1 several times. Further, the wire 10b whose one end 12b is fixed to the frame is wound around the moving pulley 5 in a U-shape,
Further, the drive pulley 1 is folded back by the fixed pulley 8.
The wire 10a is wound around the wire several times and becomes substantially integrated with the wire 10a.

The other end of the support member is also stretched in a similar manner, so that the wire 11a and the wire 11b are substantially integrated.

When assembling the optical system drive device having the above structure, the fixed ends 12a, 12b, 13a, 1
3b and the position 1 where the first mirror support member M1 is fixed.
By adjusting the fixed positions of the wires 4 and 15 and the mutual phase of the drive pulleys 1 and 2, parallelism can be achieved and the initial tension applied to the wires can be adjusted to be equal on both sides. This is because when the drive shaft 3 starts rotating and drives the mirror support member, if there is a difference in the initial tension of the wire between the two sides, the mirror support member will run tilted.

Now, we will limit ourselves to the first mirror support member M1 and mechanically examine the inclination that occurs there.

The initial tension of the wires 10a and 10b at one end is
ta, the initial tension of the wires 11a and 11b on the other end side is tb, the length of the wire between the drive pulley 1 and the fixed part 14 of the first mirror support member M1 is la, the drive pulley 2 and the first mirror support member The length of the wire between M1 and the fixed part 15 is lb. Usually, the length la and the length lb are approximately equal. Suppose now that the drive shaft 3 rotates, a force F is transmitted to both ends of the first mirror support member M1 via the wire, and it begins to move in the forward direction indicated by the arrow in the figure.
At this time, force F is also applied to the wires 10a and 10b at both ends.

Now, if the spring constant of the wire is R, The length la of the wire 10a on one end side is La=la+(F-ta)/R The length lb of the wire 10b on the other end side is Lb=lb+(F-tb)/R.

The first mirror support member M1 is maintained parallel with the wire lengths la and lb during assembly, but the wire lengths at the moment of driving are La and Lb.
In this case, unless (F-ta)/R=(F-tb)R, the parallelism of the first mirror support member M1 will not be maintained. That is, as is clear from the above discussion, during assembly, not only the static parallel state but also the initial tensions ta and tb of the wires at both ends must be equal.

However, in the past, by tensioning the wire as shown in FIG. 1, it was possible to change the positions of the stop positions 14 and 15 after adjusting the initial tension for the first mirror support member M1 and re-stop it in a parallel state. However, regarding the parallel state of the second mirror support member M2, the fixed ends 12a, 13a, 12b,
13b cannot be moved, so the second mirror support member M
2 is determined by the phases of the moving pulleys 4 and 5 and the moving pulleys 6 and 7.

Therefore, in order to adjust the parallelism of the second mirror support member M2, it is necessary to
The positional relationship between the drive pulleys 1 and 7 can be adjusted, and the mutual phase of the drive pulleys 1 and 2 can be adjusted.

Adjustment methods to match the initial tension include adjusting the positions of the fixed ends 12a, 12b, 13a, and 13b of the wire while measuring the initial tension with a spring scale, or as shown in Fig. 2. Spring 1 with small spring constant and controlled precision
6, 17, and wire fixed ends 12a, 12b, 13a, so that the displacement amount of the spring matches on both sides.
The position of 13b is being adjusted.

However, it is difficult to match accurately and adjustment takes time. After arranging the wire members,
The mirrors are aligned in parallel by fixing the first mirror support member M1 and fixing the second and third mirrors or fixing the driving pulleys 1 and 2, but this work is not easy. Furthermore, the wire tends to stretch as the number of times the optical system support member repeats its reciprocating motion increases, and due to variations in the physical properties of the wire, the amount of stretch of the wire at both ends differs, and the initial tension of the wire becomes out of order. Therefore, it is necessary to make adjustments again, which also requires a lot of time. Additionally, measurement errors in the spring scale or errors in the springs used are factors that reduce the parallelism of the mirror.

OBJECT OF THE INVENTION An optical system driving device that can easily match the initial tensions of wires on both sides during assembly, maintain optical parallelism of a dynamic mirror support member, and reduce the number of reciprocating movements of the optical system. It is an object of the present invention to provide an optical system driving device that can easily match the initial tensions of wires on both sides in a short time even if readjustment is necessary due to an increase in tension.

Structure of the Invention The present invention provides a support member M1 that supports a first mirror.
and a support member M2 that supports the second mirror are moved by wire drive at a speed ratio of 1:1/2, the first and second mirrors being moved at a speed ratio of 1:1/2. Drive pulleys 1 and 2 provided on both sides of the second mirror in the longitudinal direction and on one side in the moving direction of both the mirrors, and
Fixed pulleys 22 and 23 provided on the other side and folding back the wire from one side in the longitudinal direction of the mirror to the other side; a fixed pulley 20 that folds the wire from one side of the direction to the other side;
21, and two moving pulleys 4, 5, 6, and 7 on each side provided integrally with the support member M2 of the second mirror.
and fixed pulleys 8 and 9 for tensioning the wire from one side to the other in the moving direction of the mirror.
1, 22, 23, and the pulley groups 1, 2, 4, 5, 6, 7, 8,
9, 20, 21, 22, and 23, substantially one wire stretched symmetrically on both sides of the mirror in the longitudinal direction; and a closed loop of the wire by fixing the ends of the wire. and a tension adjustment member 24 that applies tension to the wire, and the fixing member 25 is connected to the fixing pulleys 20 and 21.
or between the fixed pulleys 22 and 23, and the tension adjustment member 24 is provided between the fixed pulleys 22 and 23.
The fixed pulleys 20, 21, 22, 2 different from 5
3, and further, the support member M1 of the first mirror is fixed to the wire stretched between the drive pulleys 1, 2 and the pulleys 4, 6. optical system drive device.

It provides:

Embodiment FIG. 3 shows an embodiment of the present invention. Items with the same reference numbers (symbols) as those shown in FIG. 1 have the same functions, so a description thereof will be omitted. The difference from the configuration of the conventional example (Fig. 1) is that fixed pulleys 20, 21, 22, 2 are newly added.
3. A tension adjustment pulley 24 for tension adjustment and a fixing member 25 are added, and the wires 10a and 11a are connected to the fixing pulley 20, respectively.
21, and is held down and fixed by the fixing member 25, so that it becomes one from the left and right.

Similarly, the wires 10b and 11b are hung on fixed pulleys 22 and 23, and then on a tension adjustment pulley 24 to form one wire. Specifically, the fixed pulleys 20, 21 and 22, 23 are for folding back the wire from one side to the other side in the longitudinal direction of the mirror, and one wire is Pulley group 1,
2, 4, 5, 6, 7, 8, 9, 20, 21, 2
2 and 23, and stretched symmetrically on both sides of the mirror in the longitudinal direction.

And both ends of the wire are each
Folded back by the fixed pulleys 20 and 21,
By being fixed by the fixing member 25, a closed loop is formed.

The tension adjustment pulley 24 for tension adjustment is connected to other fixed pulleys 22, 2 for folding back the wire.
3, and is designed to apply a predetermined tension to the wire there.

FIG. 4 is a perspective view of the main parts showing a state in which they are integrated by the fixing member 25, FIG. 4a shows the embodiment shown in FIG. 3, and FIGS. 4b and c show other embodiments. show.

With the above structure, after aligning the mirrors and adjusting the initial tension of the wires, the fixing member 25 can be tightened by tightening the small screw 26 that tightens the fixing member 25.
Press and secure a to complete the adjustment. Since the wires 10a and 11a are one piece, there is no difference in wire tension between the two ends as long as the wires are not misaligned when tightening the machine screw 26 to fix the wires after adjustment. have.

In addition, even if the wire stretches as the number of repetitions of reciprocating increases and the initial tension of the wire goes out of order on both sides, simply loosen the machine screws 26, make the mirrors parallel, and tighten them again. 11a is automatically readjusted, and the initial tension difference between the two sides is easily eliminated.

FIG. 3 shows one embodiment, and the present invention is not limited thereto, and the relative arrangement of the tension adjustment pulley 24 and the fixing member 25 may be reversed.

In addition, the tension adjustment pulley 24 and the fixing member 25
It is also possible to provide a plurality of each.

Regarding the fixing member 25, in the case of FIG.
After loosening and tightening 6a to freely move and adjust the wire, attach the frame 27 using the fixing member 25a.
It has a structure in which it is pressed against and fixed to the fixing part 27a of. FIG. 4b shows the wires 10a and 11a integrated on the fixing member 25b, with machine screws 2
6b, and remove the wire 10 together with the fixing member 25b.
After moving and adjusting the parts a and 11a to the left and right, the machine screws 26b are loosened and fixed. FIG. 4c shows the wires 10a and 11a each having its ends fixed on the fixing member 25c.
The adjustment method is the same as the embodiment of FIG. 4b. Any of these examples can be used in the present invention.

Effects of the Invention The optical system driving device of the present invention is an excellent device that can easily match the initial tension of the wire on both ends of the mirror in the longitudinal direction, and reliably guarantees parallelism of the mirror during initial assembly adjustment and movement. It turned out to be effective.

[Brief explanation of drawings]

Figures 1 and 2 show conventional examples;
The figure shows a drive system of one embodiment of the present invention. Figures 4a, b, and c all show fixing members used in the present invention. 1, 2... Drive pulley, 3... Drive shaft, 4,
5, 6, 7... Moving pulley, 8, 9... Fixed pulley, 10a, 10b, 11a, 11b... Wire member, 20, 21, 22, 23... Fixed pulley, 24... Tension adjustment pulley, 25 ... Fixing member, 26 ... Machine screw, M1 ... Mirror first support member, M2 ... Mirror second support member.

Claims (1)

[Claims] 1. A support member M1 that supports a first mirror, and a second
A type in which the support member M2 supporting the mirror is moved at a speed ratio of 1:1/2 by wire drive.
In a drive device for an optical system used in a copying machine or the like, a drive pulley 1 is provided on both sides of the first and second mirrors in the longitudinal direction and on one side in the movement direction of both the mirrors. ,2, and
Fixed pulleys 22 and 23 provided on the other side and folding back the wire from one side in the longitudinal direction of the mirror to the other side; a fixed pulley 20 that folds the wire from one side of the direction to the other side;
21, and two moving pulleys 4, 5, 6, and 7 on each side provided integrally with the support member M2 of the second mirror.
and fixed pulleys 8, 9 for tensioning the wire from one side to the other in the moving direction of the mirror.
1, 22, 23, and the pulley groups 1, 2, 4, 5, 6, 7, 8,
9, 20, 21, 22, and 23, substantially one wire stretched symmetrically on both sides of the mirror in the longitudinal direction; and a closed loop of the wire by fixing the ends of the wire. and a tension adjustment member 24 that applies tension to the wire, and the fixing member 25 is connected to the fixing pulleys 20 and 21.
or between the fixed pulleys 22 and 23, and the tension adjustment member 24 is provided between the fixed pulleys 22 and 23.
The fixed pulleys 20, 21, 22, 2 different from 5
3, and further, the support member M1 of the first mirror is fixed to the wire stretched between the drive pulleys 1, 2 and the pulleys 4, 6. optical system drive device.