JP3481691B2 - Optical adjustment device for copier - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system for adjusting the skew of the leading and trailing edges of an image in an optical system of a copying machine in which reflected light from a document is reflected, guided to a photoconductor through a lens, and imaged. The present invention relates to an optical adjustment device that adjusts a height direction of a roof mirror unit provided therein.

[0002]

2. Description of the Related Art FIG. 6 shows a schematic structure of an optical unit of a copying machine which is conventionally known and is also an object of the present invention. In FIG. 6, the photosensitive drum 1 is adapted to rotate in the direction of the arrow. Above the photosensitive drum 1, a contact glass 3 on which the original 2 is placed and an optical device 4 are installed.

The optical device 4 comprises a lamp 5 for illuminating the original 2, a lens 6, mirrors 7, 8, 9, 10, 11, 12 and the like. The lamp 5 and the mirror 7 are integrated into a unit as a scanner unit, and the original 2 is scanned in the left-right direction in FIG. Mirror 8 mirror 9
Is also unitized and moves in the same direction by ½ of the moving distance of the scanner unit to keep the optical path length constant. The state after the movement of the lamp 5 and the mirrors 7, 8 and 9 during scanning is indicated by a two-dot chain line. Here, the mirrors 10 and 11 are integrally held as a roof mirror unit 13.

The image of the original document 2 formed on the photosensitive drum 1 has the same shape as the original document 2 if the above-mentioned optical elements are arranged at correct positions. Errors and skews will occur. Among them, the skew means that an image of a line which should be perpendicular to the scanner scanning direction is tilted as shown in FIG. 7A and becomes a parallelogram as shown in the drawing.

In FIG. 6, skew occurs when the position in the height direction of one of the mirrors is different between the left and right sides of the document 2 (direction penetrating the paper surface of FIG. 6). Since it is difficult to completely eliminate this skew due to reasons such as part processing, assembly, and mechanical reasons, an optical adjustment device is usually provided, and this optical adjustment device is used, as shown in FIG. Correction to such a normal image is performed.

As this optical adjustment device, there is a technique of fixing the mirror 30 at each of the four corners thereof with screws via mounting plates 31, as shown in FIG.
843).

As another example of this optical adjustment device, FIG.
There is a device having the configuration shown in. In the example shown in FIG. 9, the roof mirror unit 13 has a substantially box shape, and the mirror 10 and the mirror 11 are supported therein at right angles to each other.

One side of the roof mirror unit 13 is pivotally attached to the optical base 15 via a hinge 14. As a result, the Dach mirror unit 13
The height can be adjusted by moving the other end side up and down with the hinge 14 as a fulcrum. Regarding the other side of the roof mirror unit 13 on which the hinge 14 is provided, an adjuster 17 is pivotally attached to a shaft 16 provided integrally with the roof mirror unit 13.

Two protrusions 17a and 17a 'are formed on the other end side of the adjuster 17, and these protrusions 17a and 17a' face each other with the optical base 15 in between. At the other end of the roof mirror unit 13, an eaves-shaped bent portion 13a is formed.
The adjusting screw 18 penetrates the hole formed in 3a with a clearance, and is prevented from coming off by the screw head. This adjustment screw 18
The front end side of the is screwed to the adjuster 17.

An extensible spring 19 is wound around the adjusting screw 18, and a force is applied to the adjuster 17 in such a direction as to separate the bent portion 13a from each other, and the weight is applied to the other end side of the roof mirror unit 13 by its own weight. The adjustment screw 18 is prevented from loosening while receiving a moment.

In this structure, the two protrusions 17a, 17
The upper protrusion 17a of a ′ is in contact with the optical base 15 under the weight of the roof mirror unit 13.
Therefore, by rotating the adjusting screw 18, the height of the other end of the roof mirror unit 13 is displaced, and it is possible to eliminate the difference in height between the one and the other end.

[0012]

In the above-mentioned prior art, since there are four screw adjusting points, the adjusting work is complicated. In the prior art, the work of assembling the adjuster 17 is complicated, such as the need for caulking work as a means for integrally providing the shaft 16 to the roof mirror unit 13. The action of the spring 19 to prevent loosening varies depending on the tightening amount of the adjusting screw 18, and the smaller the tightening amount, the smaller the spring compression amount and the more unstable the height position. Furthermore, since the direction in which the force of the spring 19 acts coincides with the axial direction of the adjusting screw 18, a force in the loosening direction is always acting on the adjusting screw 18, and the adjusting screw 18 rotates due to vibration or the like. When it is loosened, the loosening prevention effect is reduced and the height position becomes unstable.

As described above, the conventional optical adjusting device has a problem that the adjusting work and the assembling work are complicated, and the height position after the adjustment is unstable.

It is an object of the present invention to provide an optical adjusting device which can easily perform an adjusting operation and an assembling operation and can stably maintain the height position after the adjustment.

[0015]

In order to achieve the above object, the present invention is configured as follows. (1). With respect to the other end side of the roof mirror unit, a screw is screwed to bring the tip end of the screw into contact with the optical base to support the roof mirror unit, and the head of the screw and the other end side of the roof mirror unit An extensible spring is provided so as to receive a force in the direction in which the screw separates, and the winding direction of the spring is set to be opposite to the tightening rotation direction of the screw (claim 1).

(2). In the optical adjusting device for a copying machine described in (1), the end of the spring is open-ended (claim 2).

[0017]

[0018]

[0019]

The spring force acting on the adjusting screw prevents the adjusting screw from loosening without using a conventional adjuster.

[0020]

Embodiments Each embodiment described below has a part in common with the height adjusting device of the roof mirror unit 13 shown in FIG. The difference is the portion of the height adjusting device that supports the other end of the roof mirror unit 13. That is, instead of the adjuster 17 and its accompanying member, the structure according to the invention corresponding to claims 1 to 4 described below is provided.

(I) Description Corresponding to the Invention of Claim 1 FIG. 1 shows the other end side of the roof mirror unit 13 among the components shown in FIG. 9, and the same members are the same. The code is attached. In FIG. 1, from the side surface portion of the roof mirror unit 13, a bent portion 13a cut and bent from the side surface portion and another bent portion 13b facing the bent portion 13a are arranged so as to face each other. 13b
As a result, the optical base 15 is sandwiched with a margin and the detachment of the roof mirror unit 13 is prevented.

A female screw is cut in the upper bent portion 13a, and an adjusting screw 20a is screwed into the female screw and then penetrates. Further, as shown in FIGS. 1 and 2, a stretchable coil-shaped spring 21 is wound between the head of the adjusting screw 20 a and the optical base 15, and the head of the screw and the optical base 15 are wound. A force is applied to separate them.

The tip of the adjusting screw 20a is attached to the optical base 15
And receives a moment due to the own weight of the roof mirror unit 13. Therefore, the adjusting screw 20a always receives a force in a direction in which the screw 20a comes off, and tends to loosen. This also applies to each embodiment of the invention described in claim 2 , which will be described below.

The twisting direction of the adjusting screw 20a is a general right-hand screw, and the screw is formed in the tightening direction by rotating it clockwise. On the other hand, the winding direction of the spring 21 is left-handed, which is opposite to the direction in which the thread of the adjusting screw 20a is formed.

In this structure, by rotating the adjusting screw 20a, the height of the other end of the roof mirror unit 13 is adjusted, and the skew of the image can be adjusted. After the adjustment, when the adjusting screw 20a tries to rotate in the loosening direction (counterclockwise direction), the compression spring 21a tries to rotate in the direction of releasing (unwinding) the twist.

However, since the tightening rotation direction of the adjusting screw 20a and the winding direction of the loosening prevention compression spring 21 are opposite to each other,
Since the compression spring 21 extends in a direction in which the adjustment screw 20a is loosened, the compression spring 21 functions to prevent loosening. In addition, since the direction of the entrainment is the direction in which the acting force of the spring 21a increases, the entrainment is also prevented by this, and the loosening prevention is performed more reliably than in the conventional case.

In the above example, when the twisting direction of the adjusting screw 20a is right-handed, the spring 21a is wound leftward. However, the present invention is not limited to this, and the twisting direction of the adjusting screw 20a is leftward. If it is a screw, the winding direction of the spring 21 is a right-handed combination.

(Ii) Description Corresponding to the Invention of Claim 2 In the configuration according to FIGS. 1 and 2, there are a closed end and an open end for processing the end of the spring 21a. As shown in FIG. 1 and FIG. 2, the end of the spring 21a is formed so as to be in parallel contact with the back surface of the head of the adjusting screw 20a and the surface of the bent portion 13a (hereinafter referred to as the contact surface). It is the closed end, and the spring 2 shown in FIG.
Like 1a, the open end is inclined with respect to the facing surface.

Generally, there are many closed ends,
As shown in FIG. 3, by making the end open, the end of the spring acts as a catch on the abutting surface, and the function of preventing loosening is more effectively fulfilled.

(Iii) Reference Example 1 In this example, as shown in FIG.
The adjusting screw 20b is screwed through. This adjustment screw 2
Regarding 0b, a ring groove 20p is formed at the tip thereof, and an E ring 22 is fitted in this ring groove 20p.

A stretchable spring 21b is wound around the adjusting screw 20b between the E ring 22 and the lower surface of the bent portion 13a. In this example, when the adjusting screw 20b is loosened, the spring 2
Since 1b is compressed and the spring 21b is compressed, the loosening prevention function increases as the spring 21b loosens, so that the shift of the roof mirror unit 13 after the height adjustment is less likely to occur.

(Iv) Reference Example 2 In FIG. 5, the adjusting screw 20c is screwed into the bent portion 13a, and the tip of the screw 20c is projected through the bent portion so that it can contact the optical base 15. There is. Further, a washer 23 is provided to be inserted above the adjusting screw 20c. The washer 23 is a step portion 20c of the adjusting screw 20c.
It is locked by -1. Then, elastic springs 24a and 24b are provided between the washer 23 and the bent portion 13a so that the head of the adjusting screw 20c and the bent portion 13a on the other end side of the roof mirror unit come close to each other. I try to receive the force of direction.

Also in this example, the forces of the springs 24a and 24b act in the tightening direction of the adjusting screw 20. That is,
Since the springs 24a and 24b are pulled when the adjusting screw 20c is loosened, the force of the springs 24a and 24b also increases, and the shift of the roof mirror unit 13 after the height adjustment is less likely to occur.

References to Examples (i) to (iv) above
In the examples , the advantages of each example are explained in each section,
The common advantage of each of these examples is the small number of parts,
Since the configuration is simple, it is possible to easily assemble the optical adjustment device and adjust the height, and mainly
It can be pointed out that loosening of the adjusting screw due to vibration or the like during mechanical transportation can be prevented without increasing the cost.

[0035]

According to the present invention, the assembling work of the optical adjusting device and the height adjusting work can be easily performed, and
It is possible to provide an optical adjustment device that can stably maintain the height position after adjustment.

[Brief description of drawings]

FIG. 1 is a front view of the other end side of a roof mirror unit for explaining an embodiment of the present invention.

FIG. 2 is a front view of an adjusting screw portion for explaining an embodiment of the present invention.

FIG. 3 is a front view of an adjusting screw portion for explaining an embodiment of the present invention.

FIG. 4 is a front view of an adjusting screw portion illustrating a reference example of the present invention.

FIG. 5 is a front view of an adjusting screw portion illustrating a reference example of the present invention.

FIG. 6 is a diagram illustrating a schematic configuration of an optical unit of a copying machine suitable for implementing the present invention.

FIG. 7 is a diagram for explaining the influence of the height adjustment of the roof mirror unit.

FIG. 8 is a perspective view of an optical adjustment device as a conventional technique.

FIG. 9 is a perspective view of an optical adjustment device as a conventional technique.

[Explanation of symbols]

20a Adjustment screw 21 spring 21a spring

Claims (2)

(57) [Claims] 1. An optical system of a copying machine, which guides reflected light from a document to a photoconductor through a reflecting mirror and a lens to form an image, and is provided in an optical path for adjusting a skew of the front and rear edges of an image. As means for adjusting the height direction of the roof mirror unit, one end of the roof mirror is pivotally attached to the optical base,
In adjusting the other end side by moving up and down, a screw is screwed on the other end side to bring the tip of the screw into contact with the optical base to support the roof mirror unit. An extensible spring is provided so that the head and the other end of the roof mirror unit receive a force in a direction of separating from each other, and the winding direction of the spring is set to be opposite to the tightening rotation direction of the screw. Optical adjustment device for copiers. 2. The optical adjusting device for a copying machine according to claim 1, wherein an end of the spring is an open end.