JPH04124691A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To shorten a distance between a laser writing optical system and a photosensitive drum and to miniaturize a device even though a distance between the photosensitive drum and a destaticizing lamp is made longer by integrally attaching the destaticizing lamp to the laser writing optical unit. CONSTITUTION:An electrostatic charger 4, the incident position of laser light 5 emitted from the laser writing optical unit 11, a developing device 6, a transfer charger 7, a cleaning unit 9, and the destaticizing lamp 10 are disposed around the photosensitive drum 3 having a small diameter. The destaticizing lamp 10 is attached to cut opening provided on the upper side plate of the housing 11a of the unit 11. Therefore, the distance between the lamp 10 and the photosensitive body is made long with ease and, on the contrary, the distance between the photosensitive body and the laser writing optical unit is shortened, thereby miniaturizing the device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic apparatus that writes an image on a photoreceptor and performs exposure using a laser writing optical unit.

In an electrophotographic device such as a 41-piece laser printer, digital copying machine, or laser facsimile that writes an image onto a photoreceptor using a laser writing optical unit, a laser writing optical unit is used to write an image onto a photoreceptor that is uniformly charged by a charger. The electrostatic latent image formed on the photoreceptor by optical writing using a laser beam emitted from the system is developed by a developing device into a toner image, and then transferred to transfer paper fed to the photoreceptor from the paper feeder. After being transferred under the action of the transfer charger, the transfer paper is separated from the photoreceptor and fixed by a fixing device to complete the recording. After the transfer, the toner remaining on the photoreceptor is removed by a cleaning device, and the residual charge is removed by a charge removal lamp in preparation for the next image formation.

In this type of electrophotographic apparatus, as described above, it is necessary to arrange the exposure position of the charger 5, the developing device, the transfer charger, the cleaning device, and the static elimination lamp around the photoreceptor. If the photoreceptor is a belt-like photoreceptor or a large-diameter drum-like photoreceptor, the layout is easy and problems are unlikely to occur.

Recent electrophotographic devices, especially those for personal use, often use small-diameter photosensitive drums in order to downsize the device. In that case, the static elimination lamp and the laser optical unit need to be arranged in the same direction with respect to the photoreceptor drum, which makes it difficult to arrange them in terms of space. Particularly when light emitting diodes (LEDs) are used as the static elimination lamp, in order to reduce the number of LEDs and reduce costs, it is necessary to increase the distance between the photoreceptor and the static elimination lamp, which further requires space.

Problems to be Solved by the Invention In view of the above-mentioned circumstances, the present invention makes it possible to easily arrange a static elimination lamp even when a small-diameter photoconductor drum is used, and to increase space even when the static elimination lamp is separated from the photoconductor. An object of the present invention is to provide an electrophotographic apparatus equipped with a laser writing optical unit that contributes to the /I) type of apparatus without having to do so.

In order to solve the above problems, the present invention provides an electrophotographic apparatus having a laser writing optical unit, characterized in that a static elimination lamp is integrally attached to the laser writing optical unit. do.

By integrally attaching the static elimination lamp to the laser writing optical system, there is no need for a guide rail for attaching the static elimination lamp, which was required when installing the static elimination lamp independently as in the past. There is no need for installation space, and even when the static elimination lamp is provided apart from the photoreceptor, it can be easily placed, and the device can be prevented from becoming larger.

In particular, if the static elimination lamp is built into the housing of the laser writing optical unit, the distance between the photoreceptor and the static elimination lamp can be further increased, and the static elimination lamp can be manufactured at low cost.

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

FIG. 1 is a diagram showing an overall schematic configuration of an embodiment of a laser printer to which the present invention is applied.

Around the small-diameter photoconductor drum indicated by reference numeral 3 in the figure, in the order of the rotation direction indicated by the arrow, there is a charger 4, an incident position of the laser beam 5 emitted from the laser writing optical unit 11, a developing device W6, A transfer charger 7, a cleaning unit 9, and a static elimination lamp 10 are provided. As described above, the toner image formed on the photoreceptor drum 3 is transferred from the paper feed tray 1 to the transfer paper fed to the transfer section between the photoreceptor 3 and the transfer charger 7, and then transferred by the fixing device 8. It is fixed and discharged outside the machine.

Now, in the conventional device, the static elimination lamp 10 was attached to a guide rail 12 provided in the device body independently of the laser writing optical unit 11, as shown in FIG.
In this embodiment, as shown in detail in FIG. 3, it is attached to a notch provided in the upper plate of the housing 11a of the laser writing optical unit 11.

Therefore, compared to the conventional case where the static elimination lamp 10 is attached to the guide rail 12, not only is there no need for a space for installing the guide rail, but it is also easier to increase the distance between the static elimination lamp 10 and the photoreceptor. Conversely, the distance between the photoreceptor and the laser writing optical unit can be shortened, and the apparatus can be made more compact.

In another embodiment shown in FIG. 4, cutouts are provided in the upper and lower plates of the housing lla of the laser writing optical unit 11 at positions corresponding to the static elimination position of the photoreceptor, respectively, and the cutouts in the upper plate are A transparent glass or resin plate 13 is attached, and the static elimination lamp 1o is inserted into the laser writing optical unit 11 from below through a cutout in the lower plate. Needless to say, the static eliminating lamp 10 is installed so that it does not block the optical path of the laser beam 5 inside the laser writing optical unit 11. By doing this, the static eliminating lamp 1
The distance between the zero and the photoconductor can be further increased, and the distance between the photoconductor and the laser writing optical unit can be reduced, which further contributes to miniaturization of the device and reduces costs. can be achieved.

As described above, according to the present invention, in an electrophotographic apparatus having a laser writing optical system, the distance between the photoreceptor drum and the static elimination lamp can be increased, and the distance between the laser writing optical system and the photoreceptor drum can be increased. Since it is possible to shorten the distance between the two, it is possible to reduce the cost.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the overall configuration of a laser printer according to an embodiment of the present invention, FIG. 2 is a side sectional view showing the positional relationship between the laser writing optical unit and the static elimination lamp of a conventional device, and FIG. FIG. 1 is a side sectional view showing the means for attaching the static elimination lamp to the laser writing optical unit of the embodiment shown in FIG. 1, and FIG. 4 is a similar side sectional view of another embodiment of the present invention. 3... Photosensitive drum 5... Laser light 10... Static elimination lamp 11... Laser writing optical unit 11a...
Laser writing optical unit housing 13...Transparent plate

Claims (2)

[Claims] (1) In an electrophotographic apparatus having a photoconductor, a laser optical unit for optically writing an image onto the photoconductor, and a static elimination lamp for eliminating potential remaining on the photoconductor after transfer, the static elimination lamp is integrated into the laser optical unit. An electrophotographic device characterized in that it is attached to a (2) The electrophotographic apparatus according to claim 1, wherein the static elimination lamp is built into the laser optical unit.