JPH0283559A - Optical printer - Google Patents

Abstract

PURPOSE:To miniaturize the title optical printer and to prevent temperature in a photosensitive drum from rising by providing a light source with plural light emission areas and using this light source for both exposure and electrostatic charging. CONSTITUTION:A fluorescent lamp 8 is an aperture type which has two aperture parts 9a and 9b, the aperture part 9a functions as the light source of an aliger, and the aperture part 9b functions as an electrostatic discharging lamp. Namely, the fluorescent lamp 8 is embedded in the shaft 7 of a photosensitive drum 1 and the shaft 7 is provided with aperture parts 9a' and 9b' corresponding to the aperture parts 9a and 9b of the fluorescent lamp 8. Light beams passed through the aperture parts 9b and 9b' remove residual charges in an area 10 on the photosensitive drum 1. Further, fans 34 are mounted on both end surfaces of the photosensitive drum 1 and when the photosensitive drum 1 is rotated, its inside air is made to flow in one direction to suppress the temperature rise in the photosensitive drum. Thus, the temperature rise in the photosensitive drum is suppressed and the space in the photosensitive drum is used effectively to miniaturize the printer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical printer, and particularly to an optical printer suitable for a structure having a light source such as an exposure device inside a photoreceptor drum or a photoreceptor belt.

[Conventional technology]

The printing process of conventional optical printers is called the Carlson method, and is published in Letters of the Society of Electrostatics Vol. 7, No. 4 (1988).
3rd year) As described on pages 216 to 224, it consists of the processes of charging, exposure, development, transfer, fixing, cleaning, and neutralization. Specifically, as shown in FIG. 2, a uniform charge is applied to the surface of the photoreceptor drum 13 by a corona charger 14, a latent image of electrostatic charge is formed by an exposure device 15, and then a developing device 16 to create a toner image corresponding to the latent image, transfer the 1-henner image on the surface of the photoreceptor drum 13 to the paper 2 using the transfer device 17, and then transfer the toner image to the paper 2 using heat or pressure using the fixing device 20. Printing is performed by fixing on a surface. Also, the photosensitive drum 13
The remaining toner on the surface of the toner is removed by a cleaning device @18, and the residual charge is extinguished by a discharge lamp 19, thereby completing a series of processes. Since this method requires many processes as described above, the device is complicated and it is difficult to miniaturize the device.

An example of a method that simplifies the process and miniaturizes the equipment compared to this method is the OPL
There is an optical back recording method J described in page 109 of the May issue of US E) in 1988. In this method, an exposure device 15 is placed inside the photoreceptor drum 1 as shown in FIG. The development process is combined into one, and the cleaning process is also omitted.The recording principle of this system is described in Oplus E 19.
It is described on pages 52 and 53 of the May 1988 issue. According to the content, the recording principle will be explained below using FIGS. 4 and 5. The photoreceptor 1 used here has a transparent conductive layer 22 and a photoreceptor layer 23 formed on a transparent base film 21. This method consists of two steps. In the first step, as shown in FIG. 4, a negative bias voltage 25 is applied to the developing roller 24, and charged toner 26, 26' is uniformly deposited on the photoreceptor layer. When image exposure 27 is then performed, holes are generated in the photoreceptor layer 23 and moved to the surface of the photoreceptor layer 23 by the negative bias voltage 25, where they are trapped and form a latent image. In the second step, a positive bias voltage 28 is applied to the resident roller 24 to remove the charged toner 26' in the non-exposed area. At this time, the charged toner in the exposed area remains attracted to the holes in the photoreceptor layer, and development is completed.

In the subsequent process, as shown in FIG. 3, the toner image is transferred onto the paper 2 by the transfer roller 11, and the toner image is fixed by the heat roller 20, thereby completing the printing.

[Problem to be solved by the invention]

However, this prior art requires separate light sources for the exposure process and static elimination process, and requires a photoreceptor drum that can house them, making it difficult to downsize the photoreceptor drum. Further, no consideration was given to the fact that the light source also functions as a heat generating body, which caused the problem of an increase in temperature inside the photosensitive drum.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide an optical printer that is compact and does not cause a temperature rise inside the photosensitive drum.

[Means to solve the problem]

The means to achieve the above objective are shown below.

Small-sized exposure devices suitable for being placed inside the photoreceptor drum include those that combine an aperture type light source and non-light-emitting optical switching elements, and arrays of light-emitting elements. In the former case, by increasing the opening of the aperture type light source, it becomes possible to use a single light source to perform the two functions of the light source of the exposure apparatus and the static elimination lamp.

Further, in the case of an array of light emitting elements, a similar effect can be brought about by providing a period in which the device is used as an exposure device and a period in which it is used as a discharge lamp. Therefore, the inside of the photoreceptor drum only needs to have a volume that can accommodate only these exposure devices, making it possible to downsize the photoreceptor drum and, in turn, the optical printer.

Regarding heat generated from the light source, temperature rise can be suppressed by providing a fan on the end surface of the photoreceptor drum.

A detailed explanation of the invention will be given using examples.

The printing process in this embodiment is based on the printing process shown in FIGS. 3 to 5.

〔Example〕

[Example 1] A liquid crystal printer head having the configuration shown in FIG. 6 is used as an exposure device. Head is fluorescent 8. It consists of a liquid crystal optical switch array panel 6 and a condenser lens 5.

As shown in FIG. 7, the liquid crystal optical switch array panel includes a signal electrode substrate 30 having a large number of signal electrodes 29 and a common electrode 3.
1 and a common electrode substrate 32 with a liquid crystal interposed between the open substrates. The intersection of the picture electrodes is a light switch 33
The fluorescent lamp 8 serving as a light source has two openings 9a, 9.
It is of an aperture type having an opening 9a as shown in FIG. 1, with the opening 9a functioning as a light source for the exposure device, and the opening 9b functioning as a static elimination lamp. A system as shown in FIG. 1 including this head is configured. The fluorescent lamp 8 is embedded in the shaft 7 of the photoreceptor drum 1, and the shaft 7 also has openings 9a', 9a' and 9b corresponding to the openings 9a and 9b of the fluorescent lamp 8, respectively.
9b' is provided. The light exiting through the apertures 9b and 9b' removes any residual charge on the area 10 of the photoreceptor drum 1. The photoreceptor drum has a structure similar to that shown in Figure 4, and is covered with glass from the inside.

It has a structure consisting of a transparent conductive layer and a photoreceptor layer.

Further, as shown in FIG. 8, fans 34 are attached to both end surfaces of the photoreceptor drum 1, and when the photoreceptor drum 1 rotates, the air inside the drum is caused to flow in one direction, thereby reducing the temperature rise inside the photoreceptor drum. Deter.

[Example 2] A movable reflector 35 as shown in FIG. 9 is provided on the surface of the fluorescent lamp 8 in [Example 1], and covers the opening 9b' during the exposure process and covers the opening 9a' during the static elimination process. Do it like this. This operation makes it possible to increase the intensity of the light used during both processes.

[Embodiment 3] By eliminating the shaft of the photosensitive drum 1, the photosensitive drum can be further miniaturized as shown in FIG. At this time, an auxiliary roller 36 is used as shown in FIG. 11 to rotate the photosensitive drum. However, all the auxiliary rollers 36 in the figure do not need to be drive rollers,
It may also include something that just spins around idle. FIG. 11 shows a case where only one auxiliary roller 36' is connected to the pulse motor 37.

[Embodiment 4] A system shown in FIG. 12 is configured using an LED array head as an exposure device. LED array head 38 is L
It consists of an ED array 39 and a condensing lens 40. The LED array head 38 is fixed, and after a series of exposure and development processes are completed, the photosensitive drum 1 is further rotated and the LED array head 38 is fixed.
The array head 38 performs static electricity removal. In this case, it is desirable that the circumferential length of the photosensitive drum 1 is not smaller than the length of the paper 2' in the paper feeding speed direction.

[Embodiment 5] A system shown in FIG. 13 is constructed using an LED array head as an exposure device. After exposure and development are performed when the LED array head 38 is at the position 41, the head 38 is rotated to the position 42 to perform charge removal. In this case, it is desirable that the circumferential length of the photosensitive drum when traced from position 41 to position 42 in the rotational direction of the photosensitive drum is set to be longer than the length of the paper 2' in the paper feeding direction.

If a film-like light-emitting sheet that can emit light from the end and side surfaces is used, an even smaller optical printer can be realized.

FIG. 14 shows an outline of the light emitting sheet 51. A control signal applied to the electrode 46 from the light emission control circuit 44 causes a -like light 49.
50 is irradiated. Among these, the plurality of light emitting parts 48 on the end face can each independently change the light emission intensity by a switching control signal applied to the electrode 45 from the switching control circuit 43.

Such a light emitting sheet can be realized as a type of EL element.

[Embodiment 6] Fig. 15 shows an example of application of the light-emitting sheet 51 to an optical printer. Light 49 whose intensity is modulated from the end face is used for image exposure, and light 50 from the side opening 47 is used for static elimination. . Other processes are the same as in FIG.

〔Effect of the invention〕

According to the present invention, the temperature rise inside the photoreceptor drum can be suppressed, and the space inside the photoreceptor drum can be used effectively to reduce the size of the printer.

Note that the present invention is not limited to optical printers that use cylindrical photoreceptor drums, but also applies to photoreceptors with other shapes,
For example, it can also be applied to an optical printer using a band-shaped photoreceptor belt.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIGS. 2 to 5 are diagrams explaining the printing process of a conventional optical printer, FIGS. 6 and 7 are diagrams showing a liquid crystal printer head, and FIG. 13 are diagrams showing another embodiment of the present invention, FIG. 14 is a diagram explaining a light emitting sheet, and FIG. 15 is a diagram showing another embodiment. DESCRIPTION OF SYMBOLS 1... Photosensitive drum, 3... Developing device, 4... Liquid crystal printer head, 8... Fluorescent lamp, 7... Shaft,
14... Corona charger, 18... Cleaning device, 19... Static elimination lamp, 9a, 9b... Fluorescent lamp opening.

Claims (1)

Claims: 1. An optical printer having a light source inside a photoreceptor drum or inside a loop of a photoreceptor belt, wherein the light source has a plurality of light emitting areas. 2. The optical printer according to claim 1, wherein the light source having the plurality of light emitting areas is also used as an exposure light source and a static elimination light source. 3. The optical printer according to claim 2 or 3, wherein the light source having a plurality of light emitting areas is a fluorescent lamp having a plurality of apertures. 4. The optical printer according to claim 4, further comprising means for selectively transmitting light from the plurality of apertures. 5. An optical printer having an exposure device inside the photoconductor drum or inside the loop of the photoconductor belt, characterized in that the exposure device is also used in the process of removing residual charges on the photoconductor. . 6. An optical printing process in which printing for one page of printing paper is completed by rotating a photosensitive drum or a photosensitive belt twice, characterized in that it is a second-rotation Gailles process. The optical printer described in item 5. 7. An optical printer having an exposure device inside a photoconductor drum or inside a loop of a photoconductor belt, characterized in that erasing is performed by rotating a light source of the exposure device. 8. An optical printer having an exposure device inside a photoreceptor drum, characterized in that it has a plurality of rollers sandwiching the surface of the photoreceptor drum in order to rotate the photoreceptor drum. 9. An optical printer having an exposure device inside a photoreceptor drum, characterized in that a light source is located on the rotation axis of the photoreceptor drum. 10. An optical printer having a light source inside a photoreceptor drum, characterized in that a fan is provided on at least one end surface of the photoreceptor drum.