JPH0119141Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is designed so that one copying process is completed with one or two rotations of the photosensitive drum, and the photosensitive member on the photosensitive drum can be replaced as necessary. The present invention relates to an electronic copying machine, and particularly relates to the arrangement of its driving motor and the structure for transmitting the rotation of the motor to the photosensitive drum.

In conventional electronic copying machines, a motor for driving the photosensitive drum is installed on the outside of the photosensitive drum around which the photosensitive drum is wound, and a motor is also installed to generate high voltage to charge the photosensitive drum. and other electrical components for control were also provided separately from the photosensitive drum. In a copying machine in which one copying operation is completed by one or two rotations of the photosensitive drum, the size of the photosensitive drum becomes large, and therefore the space in which the photosensitive drum is installed is limited. In addition, a space is required to accommodate a motor and a related speed reduction mechanism, which has the drawback of increasing the overall size of the copying machine.

This invention provides a concrete structure for making the entire photosensitive drum compact by arranging a motor for rotating the photosensitive drum within the photosensitive drum.

The electronic copying machine according to this invention will be explained below with reference to the drawings. In FIG. 1, the copying machine housing 11
A narrow opening 12 is formed in the center of the upper plate 11u in its width direction, which in the figure is perpendicular to the paper surface. On top of the upper plate 11u, a document table 13 made of, for example, a transparent glass plate is provided so as to be movable left and right in the figure. An original 14 to be copied is placed on this original table 13.

A photosensitive drum 15 is rotatably disposed within the housing 11 on one side of the opening 12, that is, on the right side in the figure, and a photosensitive member 16 is wound around the circumferential surface of the photosensitive drum 15.

A corotron 17 that generates a high voltage is disposed in the center of the housing 11 near the bottom plate 11l in close opposition to the photosensitive drum 15. By applying a high voltage between the corotron 17 and the photoreceptor 16, the photoreceptor 16 can be charged. When the photoreceptor 16 thus charged is rotated to a light image projection position 18 in accordance with the rotation of the drum 15 (clockwise rotation in the figure), an image of the original 14 is formed thereon. That is, the light source 19 is connected to the aperture 12.
located on the opposite side of the drum 15 near the
The light from the light source 19 passes through the document table 13 to the document 14.
The reflected light enters the housing 11 at a nearly right angle, and is reflected by the reflecting mirror 21 into the drum 1 in the figure.
5, the light beam is refracted to the reflection side, travels along the upper plate 11u, and is projected onto the light image position 18 of the photosensitive drum 15 by the lens 22 provided near the left side plate 11a of the housing 11. As a result, the charge on the photoreceptor 16 is removed by the reflected light from the white portion of the document 14 excluding the black portion, and a charge image is formed on the photoreceptor 16.

The charge image on the photoreceptor 16 rotates clockwise in the figure as the drum 15 rotates, and passes through the developing section 23 disposed between the photoreceptor drum 15 and the right side plate 11b of the housing 11. . In this developing section 23, toner 24 is applied to the circumferential surface of the photoreceptor 16 by a magnetic drum 25, and the toner 24 is attracted to the charges of the charge image, so that the charge image is developed into a toner image.

The toner image on the photoreceptor 16 reaches the corotron 17 again as the drum 15 continues to rotate. At a position opposite to the drum 15 in the housing 11, the bottom plate 11l
A cassette 26 is provided near the cassette 26.
One copy paper 27 stored therein is sent to the paper feed path 29 by one rotation of the feed roller 28. Copy paper 2 sent to this paper feed path 29
7 is sent through the paper feed path 29 by a pair of constantly rotating feed rollers 31 and supplied to the input side of the rotating drum 15 of the corotron 17. The fed copy paper 27 passes along the circumferential surface of the drum 15 and between it and the corotron 17. This copy paper 2
7 is supplied between the drum 15 and the corotron 17, the toner image on the photoreceptor 16 approaches the corotron 17, and when the toner image passes the position of the corotron 17, the corotron 17 transfers the copy sheet 27 to the copy sheet 27. A high voltage is applied to the photoreceptor 16, and the toner image on the photoreceptor 16 is transferred to the copy paper 27.

The copy paper 27 with the transferred toner image is
It is bent along the roller 32 provided close to the exit side of the drum 15 of the corotron 17, further bent toward the roller 33 provided near the roller 32 and away from the drum 15, and sent to the fixing section 34. It will be done. In the fixing section 34 , the copy paper 27 is fed by a feed roller 35 and heated by a heater 36 to fix the toner image on the copy paper to the copy paper 27 . The copy paper 27 thus copied is discharged from the housing 11 to the outside through the discharge port 36.

A rotating belt 37 runs around the drum 15 and the roller 33 at the edge of the circumferential surface of the photosensitive drum 15.
is wrapped around it. Therefore, the side edge of the copy paper 27 sent between the photoreceptor 16 and the corotron 17 is located between the rotating belt 37 and the corotron 17, and the rotating belt 37 moves along the rollers 32 and 33. At this time, the copy paper 27 attracted to the drum 15 side is separated by the rotating belt 37 and easily sent to the fixing section 34.

In this example, the toner remaining on the photoreceptor 16 without being transferred is removed using the light from the light source 19. In other words, in the figure, reflector 2
A rotating reflecting plate 38 is provided on the drum side between the opening 12 and the rotating reflecting plate 38, and during so-called exposure, in which the image of the original 14 is projected onto the photoreceptor 16, the rotating reflecting plate 38 is connected to the opening 12 as shown by the solid line. Although it is rotated and positioned toward the drum 15 side so as to be removed from between the plate 21 and the rotating reflector plate 38, when the light from the light source 19 is used as erasing light, the rotating reflector plate 38 is rotated to the opening 12 as shown by the dotted line in the figure. The rotating reflecting plate 38 is located between the rotating reflecting plate 21 and the rotating reflecting plate 38 to isolate the document 14 from the reflecting mirror 21 and the light from the light source 19 to the rotating reflecting plate 38.
The light is reflected by the mirror 21, passes through the lens 22, and is further projected onto the image forming position 18. Therefore, when the remaining toner that has not been completely transferred reaches the imaging position 18, the reflected light from the light source 19 via the reflecting plate 38 is applied as erasing light to erase the remaining charges. As the rotation of the drum 15 progresses and the portion of the photoreceptor 16 onto which the erasing light is projected reaches the position of the developing section 23, the toner on the photoreceptor 16 is removed by the magnetic roller 25.

On the other hand, the light reflected by the back plate 39 of the light source 19, which is provided close to the opposite side of the drum 15, travels to the right side in the figure near the upper plate 11u, and is reflected at the position of the right side plate 11b. It is reflected by the mirror 41 and travels downward along this right side plate 11b, and the reflecting mirror 4 provided below the developing section 23
2 and is projected onto the photoreceptor 16 which has passed through the developing section 23. This projected light also acts as erasing light, and most of the charge is first removed by the incidence of the erasing light in the image formation 18, but a very small amount of charge remains in the shadow of the toner. is removed, and the toner is completely removed from the photoreceptor. The photoreceptor whose charge has been completely removed in this way is charged again at the corotron 17 and begins the next copying operation. Note that the light from the original 14 is reflected by the mirror 2.
1, and is reflected by the lens 22 at the imaging position 18.
The path of the light emitted from the light source 19 is surrounded by a shielding plate 43 to shield it from the outside, and the path of the erasing light that passes from the light source 19 through the reflecting mirrors 41 and 42 is also surrounded by a shielding plate 44 and the like. It's blocked by something.

In this invention, a motor 51 for rotating the photosensitive drum 15 is disposed inside the drum 15. In order to hold the motor 51, a fixed shaft 52 is fixed to the housing 11 as shown in FIG. 2, and one end of the drum 15 is rotatably held on the fixed shaft 52. For example, the drum 15 and the back plate 1 of the housing 11
A support plate 53 is erected between the support plate 1c and the support plate 53.
The fixed shaft 52 is fixed by being inserted into the hole drilled in the hole. The axial center of the rotating drum 15 is located on the axial center of the fixed shaft 52. A shaft cylinder 55 is fixed to the center position of a frame 54 constituting one end of the back plate side of the drum 15, a bearing 56 is attached to the inner circumferential surface of the shaft cylinder 55, and a fixed shaft 52 is mounted inside the bearing 56.
is inserted, and one end of the drum 15 is rotatably held on the fixed shaft 52.

A mounting plate 57 is fixed to the end surface of the fixed shaft 52 that protrudes into the drum 15, and the bottom plate 1 of the housing is attached to the mounting plate 57.
One end of the fixing plate 58 parallel to 1l is fixed. This fixing plate 58 extends inside the drum toward the front plate 11f of the housing 11, but is bent at the intermediate portion thereof to approach the bottom plate 11l. The motor 51 is fixed on the lower part of the fixed plate 58 closer to the bottom plate 11l. A reduction gear box 59 is provided adjacent to the motor 51, and the rotation of the motor 51 is reduced in speed within the gear box 59 and transmitted to the drive shaft 61. Drive shaft 6
1 protrudes toward the front plate 11f at the axial center position of the drum 15. In this example, a circuit section 62, such as an electronic circuit that generates high voltage for the corotron 17, is attached to the fixed plate 58 on the side of the back plate of the motor 51, that is, on the higher part. The fixed shaft 52 has a cylindrical shape, and a lead wire for the electronic circuit section 62 is led out of the drum 15 through the fixed shaft 52.

The other end of the drum 15 is rotatably held on a drive shaft 61 to which the rotation of the motor 51 is transmitted. Further, this drive shaft 61 is rotatably held in the housing 11. That is, a support plate 63 is erected between the drum 15 and the front plate 11f, and a bearing 64 is fixed in a hole formed on the support plate 63. The drive shaft 61 protrudes forward from the center of the hole of the support plate 63, and a gear 65 is mounted on the protrusion. Further, a shaft cylinder 68 is fixed to the center of a frame 67 constituting one end of the front plate 11f side of the drum 15, and a drive shaft 61 is mounted inside the shaft cylinder 68 with a bearing 69.
It is rotatably inserted through the. Also, the shaft cylinder 6
8 is rotatably inserted into the bearing 64. A sleeve 71 is integrally formed at the center of the gear 65, and the sleeve 71 is inserted into the shaft cylinder 68.

A one-way rotating clutch 72 is interposed between the sleeve 71 and the barrel 68. That is, the rotation of the gear 65 is the rotation in the direction of performing the above-mentioned sequential processing necessary for the copying operation with respect to the rotary drum 15;
In the figure, the clutch 72 is engaged in clockwise rotation, but the clutch 72 is configured so that rotation in the opposite direction is not transmitted. Therefore, when the drive shaft 61 rotates, the gear 6
5 rotates, which causes the barrel 68 to rotate via the clutch 72, and thus the drum 15 to rotate.

The shaft 7 extends toward the front side at one end of the support plate 63.
3 is rotatably protruded, and a gear 74 is mounted on the shaft 73.
75 is attached, and the rotation of the gear 65 is transmitted to the gear 74 by a transmission mechanism (not shown). This causes the shaft 73 to rotate and the gear 75 to rotate. This gear 75 and a gear provided at the end of the housing opposite to the rotary drum 15, although not shown, are connected by a chain, and the chain is rotated. A movable body 77 is attached to the chain 76, and the movable body 77 is attached to the holding frame 78 of the document table 13.
installed on. A holding frame 78 of the document table 13 is movably held in the housing 11 via rails 79 and 81. Therefore, the document table 13 is the movable body 77.
It will move back and forth due to the movement of.

For example, as shown in FIG. 3, the one-way clutch 72 has a linear spring 81 wound around the sleeve 71, and one end of which is inserted into a hole 84 formed in the shaft cylinder 68 and hooked thereon. Therefore, in FIG. 3, when the gear 65 is rotated in the direction of the arrow 85, the spring 83 is rotated and the photosensitive drum 15 is rotated in the same direction, but when the photosensitive drum 15 is rotated in the same direction 86, the spring 83 is The loosening causes a slip between the spring 83 and the sleeve 71, allowing the drum 15 to rotate relatively easily.

As described above, according to the electronic copying machine of this invention, the motor 51 for rotating the drum is disposed within the photosensitive drum 15, which is better than when the motor 51 is disposed outside the drum 15. The occupied area is reduced, and the housing 11 can be configured to be compact. Also, the drum 15 has a photoreceptor 16
is wound around the drum 15, which needs to be replaced after a certain number of uses, and when replacing it, it is necessary to manually rotate the drum 15. In this case, the clutch 72 is a one-way clutch,
Therefore, by rotating the photosensitive drum 15 in a direction in which the clutch 72 is not engaged, the gearbox 5
The photosensitive drum 15 can be easily rotated regardless of the large load on the speed reduction mechanism in the motor 9 or the motor 51. In the above description, the corotron 17 charges the photoreceptor and transfers the toner, but a corotron for charging the photoreceptor and a corotron for transfer may be provided separately. Further, although the light source 19 exposes the original and generates erasing light, a separate static elimination lamp for erasing may be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of an electronic copying machine according to this invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1,
FIG. 3 is a perspective view showing an example of a one-way clutch. 11: Housing, 15: Photosensitive drum, 16: Photosensitive member, 51: Motor, 52: Fixed shaft, 53, 63:
Support plate, 55, 68: drum shaft, 61: drive shaft,
65: Gear, 69: Reduction gearbox, 72: One-way clutch.

Claims (1)

[Scope of utility model registration request] In an electronic copying machine in which a photoreceptor is removably wound around a photoreceptor drum, one end of the photoreceptor drum is rotatably held on a fixed shaft fixed to the copying machine housing, and the photoreceptor is A fixed plate is fixed to the fixed shaft in the photosensitive drum, a motor is fixed to the fixed plate in the photosensitive drum, and a drive shaft driven by the motor is rotatably held in the housing. , the other end of the photosensitive drum is rotatably held on the drive shaft,
The driving shaft is connected to the photosensitive drum by a rotation transmission means via a one-way clutch.