JPS5961865A - Process kit and image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus such as an electrophotographic copying machine or an image recording machine H.

Hereinafter, an explanation will be given using an electrophotographic copying machine as an example.

Conventionally, in electrophotographic copying machines, latent images or developed images formed on a photoreceptor drum or the like as an image carrier are transferred onto a sheet such as paper, and then these images are fixed onto the sheet using a fixing means. are doing. In addition, in the method of transferring a latent image onto a sheet, it goes without saying that the latent image is fixed after being developed. Here, as the fixing means, for example, a method using radiant heat, a method using microwaves, a method using a heater temple, etc. are used for heat fixing.

On the other hand, recently, there has been a trend toward miniaturization of the device d, and as the device becomes smaller, the distance between the image bearing member and the fixing means becomes closer, and the aforementioned heat generated from the fixing means affects the image bearing member, for example. There is a possibility that this may lead to deterioration of the image carrier, resulting in a decrease in sensitivity. Further, even if the apparatus is not small-sized, depending on the properties of the image carrier, the image carrier may be affected by the products generated from the fixing means.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an image forming apparatus capable of solving the above-mentioned problems and forming a good image without the image bearing member being affected by the fixing means.

That is, the present invention that achieves the above object includes an image carrier, a process means that acts on the image carrier, a transfer means that transfers the image on the image carrier onto a sheet, and a process that transfers the image on the image carrier after the transfer. An image forming apparatus is provided, comprising: a fixing means for fixing an image; and a shielding cover located between an image carrier and the fixing means to shield the space between the two during image formation. . Still another aspect of the present invention provides an image carrier, a process means that acts on the image carrier, a transfer means that transfers the image on the image carrier onto a sheet, and a method for fixing the image on the image carrier after the transfer. A fixing means is positioned between the image bearing member and the fixing means during image formation to shield the gap between the two, and when the main body is opened, the fixing means is moved to a position covering the surface of the image bearing member and covers the surface of the image bearing member. The present invention provides an image forming apparatus characterized by having a shielding cover for shielding.

This will be explained below using the drawings. Note that the embodiments described below use a heated fixing roller as the fixing means.
Further, a case is shown in which an organic semiconductor photosensitive layer, a zinc oxide photosensitive layer, or the like is used as the image carrier. Roughly speaking, in this embodiment, when the main body is split open in the vertical direction, it is used as a shielding cover.
Although an example has been shown in which the surface of the transfer area of the image carrier is covered and also serves as a light shielding function, the present invention is not necessarily limited to this example.

FIGS. 1 and 2 are diagrams illustrating the configuration of an embodiment of an electrophotographic copying machine. FIG. 2 shows the main body of the copying machine shown in FIG. 1 in an open state. In FIG. 1, reference numeral 1 denotes a document mounting table made of a transparent member such as glass, which reciprocates in the direction of the arrow a on the tray/L/R. Reference numeral 2 denotes a converging light transmitting body, which irradiates the original image O on the original table 1 with an illumination lamp L, and slit-exposes the reflected )°C image onto the photosensitive drum 3. Note that the photosensitive drum 3 rotates on the shaft 3C in the direction indicated by the arrow. Is 4 a corona band device that uniformly bands the photosensitive drum?
Inflict madness. Further, a developing device 5 visualizes an electrostatic latent image formed by applying 11,211 light beams from the converging light transmitting member 2 to the uniformly charged photosensitive drum. Incidentally, the photosensitive drum 3 is a roller 3b made of aluminum whose surface is coated with an organic semiconductor photosensitive layer, a zinc oxide photosensitive layer, or the like.

On the other hand, C) P is the feed roller 6 and the register roller 7.
The image is fed onto the 3 sides of the drum, and the image on the drum is transferred by the transfer corona discharger 8. After the transfer, the sheet is separated from the citrum surface by the separating means 13 and guided by the guide 9.
It passes through the rollers 9 & 2 and is sent to the heating roller fixing device 10. The toner image on the sheet is fixed by the fixing device 10, and the sheet is discharged onto the sheet tray 12 by the discharge row 211. Further, the toner remaining on the photosensitive drum 3 is removed and collected by the cleaning means 14.

Furthermore, Ic, 15 is an illumination system that exposes the original, and 16 is a heat lI.
It is a filter such as an a-absorption filter. Here, the heating roller fixing i10 is the heating roller 10 having a built-in heater H.
a and a fixing roller lob that is in pressure contact with the roller 10a.

Now, this copying machine is divided into an upper housing 17 and a lower housing 18. Both housings 17 and 18 are connected by a support shaft 19, and the upper housing 17 is moved around the support shaft 19 by a spring 19.
It is configured to move upward tIJI by a. Image forming means such as the illumination optical system 2 and 15, the photosensitive drum 3, the developing means 5, and the cleaning means 14 are arranged in the upper housing 17.

Further, in the lower housing 1, a feeding roller 6, a transfer corona discharger 8, a separating means 13, a guide 9, a heating roller fixing device l, and the like are arranged on the sheet conveyance path.

Here, reference numeral 20 denotes a shielding cover made of, for example, ABS resin, which has a curved shape and has heat insulating properties, and shields heat from the fixing device 10 from reaching the photosensitive drum 3 . That is, when the lower housing 17 and the lower housing 18 are closed and the copying is possible, the shielding cover 20 is located between the fixing device and the photosensitive drum 3, as shown in FIG. By turning off the heater H, the heat emitted from the heating roller 10a is prevented from reaching the circumferential surface of the photosensitive drum 3. Therefore, in this embodiment, the shielding cover 20 prevents the heat from the fixing device 10 from reaching the circumferential surface of the optical drum 3, or reduces the amount of heat reaching the circumferential surface of the drum 3. It is possible to prevent deterioration phenomena such as a decrease in sensitivity, and also to prevent deformation of the aluminum roller 3b due to heat. Further, in this embodiment, when the shielding cover 20 is located between the fixing device 10 and the photosensitive drum 3, a part of the cover 20 is attached to the cleaning means 14.
The cleaning means 14 is located so as to surround the outer wall of the cleaning means 14.
It is also possible to reduce the effect of heat on

Further, in this embodiment, the shielding cover 20 also has a light shielding function. That is, when the upper housing 17 and the lower housing 18 are opened for maintenance or the like, it also has a function of blocking light so that the surface of the photoreceptor is not exposed to light.

The configuration of this shielding cover 20 and its S movement mechanism will be explained below.

FIG. 5 shows an example of the configuration of this shielding cover 20.

In the figure, there are swing arms 21 and 21b at both longitudinal ends of the drum on the same axis 3a as the photosensitive drum 3, and the ends of the swing arms 21 and 21b are rotatably fitted to both longitudinal ends of the shielding cover 20 by a shaft 33. . Further, both ends in the longitudinal direction of the other end of the shielding cover 20 are rotatably engaged with the swing arms 221L and 22b via a shaft 34. Further, the swing arms 22IL and 22b are fixed to the shaft 23.

Further, an actuation lever 25 is fixed to the end of the shaft 23.

As shown in the figure, the swinging arms 21a and 21b are given a counterclockwise rotational habit by a spring 24 (a similar spring may be provided on the arm 21b side if necessary). That is, the cover 20 is always placed in a position that covers the surface of the drum 3. Here, the spring 24 is applied to the internal force of the kit 30 which will be described later/(-30d) and the arm 21
Its both ends are locked by the protrusion 24b on iL (FIGS. 3 and 4).

In the above configuration, when the operating lever 25 is moved clockwise by a mechanism to be described later, the shaft 23 also rotates clockwise, and the swing arms 22a and 2 whose one end is fixed to this shaft
2b, the cover 20 can be rotated clockwise. Therefore, this cover 20 can be retracted from the position covering the surface of the photosensitive drum 3 (this state can be
(shown in figure).

Furthermore, in this embodiment, as shown in FIG. 3, a protrusion 26 is integrally fixed to the lower housing 18.
6 closes the upper housing 17, it comes into contact with the operating lever 25, pushes up the lever 25, and moves the operating lever 25 clockwise.

Then, by closing the upper housing 17, the cover 20
is automatically retracted from the surface of the drum 3, the transfer area is opened, and image formation becomes possible. As shown in FIG. 1, the cover 20 is located between the fixing device 10 and the photosensitive drum 3 and functions as a heat shield for the photosensitive drum 3.

Furthermore, when the upper housing 17 is opened, the engagement between the operating lever 25 and the projection 26 is broken, as shown in FIG. Therefore, the swinging arms 21a and 21b rotate counterclockwise due to the elastic force of the spring 24, and in conjunction with this, the heat shield cover 20
rotates counterclockwise to a position facing the surface of the drum 3, and comes to cover the exposed portion (transfer portion) of the photosensitive drum 3 from the transfer opening of the frame 30a. That is, when the upper housing 17 is opened, the shielding cover 20 automatically covers the exposed portion of the surface of the drum 3, so that it also functions to shield the surface of the drum 3 from light.

As described above, in this embodiment, the shielding cover 20 has both heat shielding and light shielding functions.

Furthermore, in this embodiment, a kit 30 is constructed which integrates image forming means such as an Iil photo drum 3, a developing device 5, a developing device 14, and a charging device 4, and when replacing the photosensitive drum, each unit is replaced at the same time. The idea is to reduce maintenance work by replacing them. H-chi, kit 3O
f: It is detachable along the rails 31 and 32 on the copying machine main body side. Therefore, the photosensitive drum 3 and the developing device 5 around it
- Even when removing the cleaner 30 that integrates the cleaning means 14, charger 4, etc. from the main unit, the above embodiment can be removed with the exposed portion of the photosensitive drum 3 covered with the shielding cover 20. . Therefore, since light can be prevented from hitting the surface of the photosensitive drum 3, deterioration of the photosensitive layer can be prevented and operability can be greatly improved.

In particular, when the kit 30 is configured as a kit, the periphery of the kit 30 except for the transfer opening Q is covered with a frame 30a. At this point, the kit 30 is pulled out from inside the copying machine main body to the bright outside of the main body, but in this embodiment, this transfer opening Q is covered with the shielding cover 20, so the effect of light passing to the photoreceptor surface is further improved. do. Note that as the material of the frame 30a, the same material as the shielding cover can be appropriately selected and used, but in this embodiment, rigid ABS resin is used and its surface is black to enhance light shielding properties. .

In this embodiment, an example is shown in which the process kit includes a developing device, a cleaner, a charger, etc. as process means in addition to the photosensitive drum; however, this embodiment is not limited to this. Of course, it is also possible to incorporate a part of the process means, such as a cleaner and an image carrier, or a developing device and an image carrier, or a combination of a cleaner, a charger, and an image carrier, into a process kit. . ff1J The process kit only needs to integrally include part or all of the image carrier and the process means. It goes without saying that the image carrier and the process means may each be detachably attached to the kit individually.

Tsukagami As described above, according to this embodiment, when the copying is possible, the effect of heat on the photosensitive drum 3 can be reduced by the shielding cover 20, and when the kit 30 is taken out from the main body 0, the photosensitive drum 3 is The exposed portion of the drum 3 (i.e., the frame body 30
The cover 20 can cover a portion (corresponding to the transfer opening Q provided for transfer in FIG. 1A) with the cover 20. Therefore, the photosensitive drum 3 is blocked from light, that is, the kit 30 can be taken out from the main body C without causing deterioration of the photosensitive layer, and the kit book 3o can also be stored while being taken out from the main body 0. .

Further, by appropriately selecting the material of the shielding cover 20, it is possible to not only shield heat and light but also prevent damage to the surface of the photosensitive drum 3.

The cover 20 may be made of various known materials such as plastic resin such as ABS resin, wood, opaque glass, hard rubber, asbestos, or metal such as iron.

For example, if the main function of the shielding cover trap is heat insulation, the cover may be transparent, or if it is to have a light shielding function, it may be made of ABS resin, which has light shielding properties in addition to heat shielding. All you have to do is select the material. Furthermore, if a shock-resistant, rigid material is selected from among these materials, the kit can be installed and removed without covering the photosensitive drum 3 with a cover and exposing it. There will be no damage.

Here, regarding another embodiment of the shielding cover, Fig. 7 (&)
-Explain using (b).

The shielding cover shown in FIG. 7 (&) has higher heat insulation and light shielding functions.

In the figure, the shielding cover 35 has an inner surface 35a on the side facing the photosensitive drum that is black to enhance the light-shielding function, and an outer surface 35b that is white or glossy to increase the heat reflection efficiency and enhance the heat insulation function. It is something.

Furthermore, the shielding cover shown in FIG. 7(b) has a higher heat insulation function.

In a part of the figure, 36 is a shielding cover, and its outer surface 36b
A large number of protrusions 36o are provided on the periphery. As a result, the real protrusion 36c can perform a heat dissipation function, thereby improving the heat insulation function. In any of the embodiments, the material of the cover may be a rigid glass resin such as ABS resin, but it is of course possible to use other materials as appropriate.

In this embodiment, when the upper housing 17 is closed, the shielding cover 20 is retracted to the above-mentioned position, so the fan 27
The flow path of the air generated by this can be guided toward the ozone decomposition filter 28 by this shielding cover 20. Therefore, when an air current is generated by the fan 27 to prevent ozone around the charger 4 and temperature rise in the cleaning means 14, for example, this air current can also prevent the outer fan of the cover 20 from being blocked. Here, in Fig. 6, the wind flow path is indicated by arrow A-
Indicated by B-0. In particular, the temperature of the cover 20 is prevented from rising by the air flow from the vicinity of the transfer corona discharger 8 toward the filter 28, as indicated by the arrow 11:IJA.

In addition, 27 is a cloth 70-fan, and 28 is an ozone decomposition filter.

In addition, in this implementation, the case where the upper casing is released due to jam clearance, etc. has been explained as an example, but it goes without saying that a similar shielding cover moving mechanism can be constructed even when the casing is not divided into upper and lower halves. . In this case, the operating lever may be moved clockwise to move the shielding cover to the retracted position, and then the lever may be locked.

Note that the image carrier is not limited to a photosensitive drum, and may be one that forms an image using a magnetic latent image, or may be an insulated drum or the like. Further, the belt is not limited to a drum, but may be an endless belt or the like. Furthermore, in this embodiment, an example is shown in which the shielding cover is used to insulate heat from the fixing means, but the shielding cover is not limited to a heat insulating function, but also has a light shielding function, for example, to prevent light from reaching the image carrier during flash fixing. Of course, it is also possible to have the following.

Further, an example of opening the main body is not limited to an example in which the main body is divided vertically, and for example, the front door is opened. Alternatively, it also includes rotating the transfer material conveyance path downward to open it. Furthermore, the present invention includes
It goes without saying that the present invention can also be applied to an open latent image transfer method in which the latent image is transferred onto a sheet and then developed.

As described above, the present invention prevents or reduces the generation of heat emitted from the fixing means that affects the image bearing member from reaching the peripheral surface of the image bearing member, thereby forming a good image. The present invention provides an image forming device capable of forming images.

[Brief explanation of drawings]

FIG. 1 is an internal side view of a abdominal imaging device to which an embodiment of the present invention is applied, FIG. 2 is an internal side view showing the main body in an open state, and FIGS. 3 and 4 are a moving mechanism for the shielding cover. FIG. 5 is a perspective view of another embodiment of the shielding cover.

Claims (5)

[Claims] (1) An image carrier, a process means that acts on the image carrier, a transfer device that transfers the image on the image carrier onto a sheet, and a fixing device that fixes the image on the image carrier after the transfer. An image forming apparatus characterized by having a shielding cup located between an image bearing member and a fixing means to shield the gap between the two during image formation. (2) an image carrier, a process means that acts on the image carrier, a transfer device that transfers the image on the image carrier onto a sheet, and a fixing device that fixes the image on the image carrier after the transfer. During image formation, a shield is positioned between the image carrier and the fixing means to shield the space between the two, and when the main body is opened, the shield moves to a position to cover the surface of the image carrier to shield the surface of the image carrier. An image forming apparatus comprising: a cover. (3) The image forming apparatus according to claims (1) and (2), wherein the shielding cover has heat insulating properties. (4) The image forming apparatus according to claims (1) and (2), wherein the shielding cover has a light shielding property. (5) The image forming apparatus according to claims (1) and (2), wherein the shielding cover has rigidity.