JPH0643792Y2 - Drive band tension adjustment mechanism for shading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a drive band tension adjusting mechanism for a shading device installed in a copying machine or the like.

[Conventional technology]

In FIG. 2, a contact glass 2 is arranged above the copying machine 1, and the document placed on the contact glass 2 is uniformly illuminated by the certification device 19. The reflected light from the document is imaged on the surface of the belt-shaped photoreceptor 8 via the imaging lens 3 as shown by the solid line. A light-shielding device 70 including a front-side light-shielding device 35 and a rear-end light-shielding device 36 is disposed between the lens 3 and the photoconductor 8 to prevent an area where a document image is not projected in the moving direction of the photoconductor 8. The light is shielded from the front end and the rear end.

The belt-shaped photoconductor 8 is rotated counterclockwise according to a belt support roller 15 rotated by a driving device (not shown). The surface of the photoconductor 8 is charged by the charging device 14, and an original image is projected on the exposed area to form an electrostatic latent image. Then, after the excess charge is removed by the eraser 7, toner is supplied from the developing device 9 to the electrostatic latent image on the photoconductor 8 to form a toner image.

Then, the transfer paper is sent from the paper feeding device 16 onto the photoconductor 8,
The toner image is transferred onto the transfer paper by the action of the transfer charger 10. Further, the electrostatic attraction of the transfer paper to the photoconductor is weakened by the separation charger 11, and the transfer paper is separated from the photoconductor 8 and conveyed to the fixing device 12, where the toner image is fixed. The toner remaining on the photoconductor 8 is removed by the cleaning device 13.

When the copy magnification is changed and the transfer paper size is changed, the above-mentioned light shielding device 70, that is, the front end side light shielding device 35 and the rear end side light shielding device 36.
As shown by the phantom line, the light shields the area of the exposure area of the photoconductor 8 where the original image is not projected.

As shown in FIG. 3, the shading device 70 includes a tip side shading device 35 for regulating the latent image tip position and a tip side shading device.
It has the same shape as 35 and includes a rear end side light shielding device 36 that regulates the rear end position of the latent image.

In the figure, reference numerals 38 and 39 denote outer pulleys of the front light-shielding device 35, and reference numerals 41 and 42 denote outer pulleys of the rear light-shielding device 36. These outer pulleys 38, 39, 41, and 42 are wound around the light-shielding sheet. It is attached to a shaft 22 which is rotatably supported by the roll 6. Both ends of the shaft 22 are supported by bearings fixed to a frame (not shown).

Reference numerals 43 and 44 denote inner pulleys of the tip side light shielding device 35, and reference numeral 4
Reference numerals 5 and 46 denote inner pulleys of the rear end side light shielding device 36. The inner pulleys 43 and 45 and the inner pulleys 44 and 46 are arranged adjacent to each other on the same track, and are rotatably supported by a bracket (not shown).

A drive belt 34a as a drive band is wound around the outer pulley 38 and the inner pulley 43 of the tip-side light-shielding device 35, and a drive belt 34b is wound around the outer pulley 39 and the inner pulley 44. The drive belt 34c is wound around the outer pulley 41 and the inner pulley 45 of the rear end side light-shielding device 36, and the drive belt 34d is wound around the outer pulley 42 and the inner pulley 46. Both ends of the angle 4 are fixed to the lower surfaces of the drive belts 34a, 34b, 34c, 34d by belt stoppers 27.

Reference numeral 5 indicates a light shielding sheet as a shielding member, and its width P
Is almost equal to the width of the photoconductor 8. This shading sheet 5
The front end side is fixed to the angle 4 and the rear end side is fixed to the light-shielding sheet winding roller 6, and the light-shielding sheet 5 having a constant length is wound around the light-shielding sheet winding roller 6. The shaft 22 and the shading sheet take-up roller 6 are torsion springs 23.
The back-tension is constantly applied to the light-shielding sheet 5 by the rotation torque of the torsion spring 23.

The power transmission gear 30b is integrally formed with the inner pulleys 44 and 46. A pinion 30a attached to the motor 26 meshes with the power transmission gear 30b.

In this light-shielding device 70, the motor 26 operates when the copy magnification is changed and the transfer paper size is changed, and the power of the motor 26 is transmitted from the pinion 30a to the power transmission gear 30b, so that the inner pulley 4
The rotation of the inner pulleys 44 and 46 drives the drive belts 34a, 34b, 34c and 34d. Then, the light-shielding sheets 5 and 5 are pulled out or wound up from the light-shielding sheet winding roller 6, and the light-shielding sheet 5 is opened and closed to adjust the length dimension of the exposure area of the photoconductor 8.

In order to smoothly open and close the light shielding sheet, the drive belt 34 must be appropriately tensioned. Therefore, the tension adjustment mechanism 31 or
Equipped with 50.

The idle pulley 32 of the tension adjusting mechanism 31 is arranged so as to come into contact with an intermediate portion on the upper surface side of the drive belt 34b. The idle pulley 32 is rotatably attached to the tension adjusting plate 33. The tension adjusting plate 33 has two elongated holes 47 extending in the vertical direction. A screw 48 is inserted into this long hole 47, and the tension adjusting plate
The 33 can be fixed to a frame (not shown). The drive band tension adjusting mechanism 31 is provided on all four drive belts 34a, 34b, 34c, 34d (not shown).

In this tension adjusting mechanism, the tension adjusting plate 33 is temporarily attached to the frame with the screw 48, and the tension adjusting plate 33 is moved up and down to press the idle pulley 32 against the drive belts 34a, 34b, 34c, 34d for driving. Screw the tension adjustment plate 33 at the position where the desired tension is applied to the belt.
It is fixed to the frame by and the tension of the drive belt 34 is adjusted.

In the tension adjusting mechanism 50, the outer pulley 42 is rotatably attached to a support plate 51 that can move in the direction in which the drive bands 34a, 34b, 34c, 34d are bridged (hereinafter referred to as AB direction). Reference numeral 52 denotes a spring stop plate, and the spring stop plate 52 is formed with an elongated hole 54 extending in the AB direction. The spring stop plate 52 is attached to the frame by a screw 55 inserted in the long hole 54. The support plate 51 and the spring stop plate 52 are connected by a spring 53. This drive band tension adjusting mechanism 50 is provided on all four drive belts 34a, 34b, 34c, 34d (not shown).

With this tension adjusting mechanism, the spring stop plate 52 is appropriately moved in the AB direction by the screw 55, and the spring stop plate 52 is fixed to the frame by the screw 55 at a position where a desired tension is applied to the drive belt 34, and the drive belt 34a, Adjust the tension of 34b, 34c, 34d.

[Problems to be solved by the device]

In the drive band tension adjusting mechanism of the conventional light shielding device,
Since the drive belts 34a, 34b, 34c, 34d must be provided with the adjusting mechanism, the number of parts is large and the assembly is complicated.

Further, since the tension adjusting plate 33 or the spring stop plate 52 is moved subtly to adjust the tension of the drive belts 34a, 34b, 34c, 34d, the adjusting work is troublesome.

Further, when the lengths of the drive belts 34a, 34b, 34c, 34d change with time, the tension of the drive belts also changes, so that there is a problem in that the tension needs to be adjusted again.

[Means for Solving the Problems]

The present invention has been made by paying attention to the above-mentioned conventional problems, and a plurality of outer pulleys, a plurality of inner pulleys arranged adjacent to each other on the same track, and these outer pulleys and inner pulleys are independent of each other. Of a light-shielding device that is provided with a drive belt that is hung around the drive belt and a shield member that is attached to the drive belt and that is opened and closed by rotating the pulley to shield the exposure area of the photoconductor. In the drive band tension adjusting mechanism, the outer pulley is attached to an immovable member, and the adjacent inner pulley is
It is movable in the orbital direction and is connected to each other by an elastic member.

[Action]

According to the tension adjusting mechanism of the light-shielding device, the outer pulley is attached to the immovable member, and the adjacent inner pulleys are movable in the track direction, so that the inner pulleys are moved closer to each other by the elastic force of the elastic member. Pulled in the direction,
The drive band is pulled.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

The light-shielding device shown in FIG. 1 has the same structure as the conventional example except that the drive band tension adjusting mechanism of the present invention is particularly provided. Therefore, only the tension adjusting mechanism will be described in the embodiments. For the description of the configuration, the same reference numerals as those in the conventional example are given and the description thereof is omitted.

In the figure, reference numeral 60 indicates a tip side bracket, and the tip side bracket 60 is supported by a frame (not shown) so as to be movable in the AB direction. The tip side bracket 60 includes inner pulleys 44, 46 integrally formed with the power transmission gear 30b.
Is supported on the entire surface of the bracket.
Further, the tip end side bracket 60 is provided with a motor 26, and the motor 26 is provided with a pinion 30b. The pinion 30a is located on the front surface of the front end side bracket 60 and meshes with the power transmission gear 30b. A hook 60a is formed on the side edge of the tip side bracket 60 on the B direction side.

The rear end side bracket 61 has a hook 61a on the side end edge on the A direction side.
Has the same structure as the front end side bracket 60 except that it is formed so as to face the hook 60a.

Hook 60a on the front bracket 60 and the rear bracket 61
A spring 62 is hooked on the hook 61 a of the bracket 61, and the brackets 60, 61 are connected to each other by the spring 62. The spring 62 exerts a certain elastic force that gives proper tension to the drive belts 34b and 34d.

Reference numeral 64 indicates a front end side bracket that supports the inner pulley 43, and the front end side bracket 64 can move in the AB direction. A hook 64a is formed on the side edge of the tip side bracket 64 on the B direction side.

Reference numeral 65 indicates a rear end side bracket that supports the inner pulley 45, and the rear end side bracket 65 can move in the AB direction. A hook 65a is formed on the rear end side bracket 65 so as to face the hook 64a of the front end side bracket 64.

Hook 64a of the front bracket 64 and the rear bracket 65
A spring 66 is hooked on the hook 65a of the bracket 65 and the brackets 64 and 65 are connected by the spring 66. This spring
Reference numeral 66 is for giving proper tension to the drive belts 34a, 34c.

These front side brackets 60 and 64 and rear side brackets 61 and 65
A tension adjustment mechanism is configured by the springs 62 and 66.

In the tension adjusting mechanism of the shading device of this embodiment, the spring
The front end side brackets 60, 64 and the rear end side brackets 61, 65 are pulled toward each other by the elastic force of 62, 66, and the front end side inner pulleys 43, 44 and the rear end side inner pulleys 45, 46 are By pulling in the same direction, the drive belts 34a, 34b, 34c, 34d are pulled, and proper tension is given to the drive belt 34.

Although the drive belt is used as the drive band in the embodiment, the present invention is not limited to this, and a chain can be used instead of the drive belt.

[Effect of device]

As described above, according to the present invention, since it is possible to apply an appropriate tension to the drive band only by the structure in which the inner pulleys are connected by the elastic member, the number of parts can be reduced as compared with the conventional tension adjusting mechanism. Assembling work is also easy. Further, since the tension of the drive band is automatically set by the elastic force of the elastic member, it is not necessary to perform a troublesome adjustment work. Further, since the inner pulley is connected by the elastic member, it is possible to cope with the change over time in the length of the drive band.

[Brief description of drawings]

FIG. 1 is a perspective view of a shading device of the present invention, FIG. 2 is a schematic view of a copying machine equipped with the shading device, and FIG. 3 is a perspective view of a conventional shading device. 5 ... Shading sheet, 34a, 34b, 34c, 34d ... Driving belt, 3
8,39,41,42 …… Outer pulley, 43,44,45,46 …… Inner pulley, 62,66 …… Spring, 60,64 …… Tip bracket,
61,65 …… Bracket on the rear end side.

Claims (1)

[Scope of utility model registration request] 1. A plurality of outer pulleys, a plurality of inner pulleys which are arranged adjacent to each other on the same track, and drive bands which are independently wound around the outer pulley and the inner pulley, respectively. In a light-shielding device, which is attached to a drive band and is opened / closed by rotation of the pulley to shield the exposure area of the photoconductor, the outer pulley is attached to a non-moving member and is adjacent to the non-moving member. The drive band tension adjusting mechanism of the light-shielding device is characterized in that the inner pulleys that are movable in the orbital direction are connected to each other by elastic members.