JPH0242226B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a sequential exposure type electrophotographic printer using electrostatic photography.

TECHNICAL BACKGROUND AND PROBLEMS A conventional electrophotographic printer of this type will be explained with reference to FIG. First, a drum-shaped photoreceptor 1 is provided to rotate clockwise, and a charging portion 2 using a coroton charger is provided on a portion of the outer periphery of the photoreceptor 1, the width of which corresponds to the width of the photoreceptor 1. Also,
an exposure device 3 that reciprocates in the generatrix direction of the photoreceptor 1;
is provided. When the exposure device 3 is driven to perform optical writing, the photoreceptor 1 stops rotating. Next, a developing device 4 is provided. This developing device 4 has a permanent magnet roller 7 housed in a container 6 that holds toner 5, and visualizes the electrostatic latent image formed by the exposure device 3.

Further, a corotron transfer device 8 is provided above the photoreceptor 1, and the toner 5 is deposited on a transfer portion 9 made of plain paper, and the toner image is fixed by a fixing device (not shown). Next, the entire surface of the photoreceptor 1 is irradiated with light by the static eliminator 10 to erase the electrostatic afterimage, and the cleaning device 11 removes the residual toner.

In this way, image information is formed on the transfer paper 9 by intermittently feeding the photoreceptor 1 row by row and driving the exposure device 3 row by row. In such a structure, each process part, such as the charging section 2, the exposure device 3, the developing device 4, the corotron transfer device 8, the static eliminator 10, and the cleaning device 11, is arranged in a satellite shape around the outer periphery of the photoreceptor 1. This makes the device extremely large and has a structure that is unsuitable for use as a printer.

OBJECTS OF THE INVENTION An object of the present invention is to obtain an electrophotographic printer that can be made smaller and lighter.

Summary of the Invention The present invention includes a charging section, an exposing section, and a developing section mounted on a carrier that reciprocates along a photoconductor to perform charging, optical writing, and development for each row. The structure is such that it can be made smaller by reducing the number of parts to be disposed around it, and it can also be made lighter.

Embodiment of the Invention A first embodiment of the invention will be described with reference to FIGS. 2 and 3. First, a drum-shaped photoreceptor 12 is provided, and this photoreceptor 12 is connected to a drive device (not shown) so as to be intermittently fed row by row in a counterclockwise direction. Below the photoconductor 12 is a carrier 13 guided by a guide shaft (not shown).
is provided so that it can freely move back and forth. This carrier 1
3, a charging section 14, an exposing section 15, and a developing section 16 are sequentially arranged from the right side.

The charging section 14 is constituted by a shield type corotron charger in which the length of the discharge wire is set to be slightly larger than the height of the characters to be printed. Further, the exposure section 15 is a combination of a focusing rod lens array 17 and an LED array 18. Furthermore, the developing section 16 has a toner container 20 that stores the toner 19, and the outer peripheral surface of the toner container 20 is located inside the photoreceptor 1.
Permanent magnet roller 2 that maintains a constant distance from the surface of 2.
1 is provided. This permanent magnet roller 21 is fixed to the end of a support shaft 22 that passes through the toner container 20, and this support shaft 22 is supported by a bearing 23, and a pulley 24 is fixed to the other end. A wire 25 with both ends fixed is wound around it.

Further, a transfer section 27 through which the transfer paper 26 passes, a static eliminator 28, and a cleaning section 29 are arranged around the photoreceptor 12.

In such a configuration, the carrier 13 reciprocates while the photoreceptor 12 is stopped; when it moves to the right, it is in the recording state, and when it moves to the left, it is in the return state. Now, when the carrier 13 moves to the right, the photoreceptor 12 is charged by the charging section 14, and the LED array 18 is driven in accordance with the image signal to expose the photoreceptor 12 through the focusing rod lens array 7. Forms an electrostatic latent image. For example, the surface of the photoreceptor 12 is
It is charged to 400V, and at the exposed point of the photoreceptor 12, the voltage rapidly drops to about +20V, and the potential difference with the non-exposed area becomes 380V, forming an electrostatic latent image. Next, in the developing section 16, toner 19 adheres to the surface of the photoreceptor 12 corresponding to the electrostatic latent image and is visualized. That is, as the carrier 13 moves, the wire 25 rotates the pulley 24, and the permanent magnet roller 21 transfers the toner 19 to the photoreceptor 1.
Supply to the surface of 2. At this time, the length of the spikes of the toner 19 is controlled to a constant height by a doctor (not shown).

In this way, by moving the carrier 13 in one direction, one line is visualized, and after the photoreceptor 12 has rotated by one line, the carrier 13 returns to its original position.

Next, a second embodiment of the present invention will be described based on FIGS. 4 to 6. Components that are the same as those described in FIGS. 2 and 3 are designated by the same reference numerals, and description thereof will be omitted. In this embodiment, first, the developing section 16
An exposure section 15 and a charging section 14 are respectively disposed on both sides. Thereby, optical writing and development are possible in any case when the carrier 13 is reciprocating. Therefore, speeding up can be achieved.

Further, the permanent magnet roller 21 is driven by a motor 30, and an exposing section 15 and a charging section 14 are also provided in the row scanning direction. The exposing section 15 and the charging section 14 are arranged obliquely so as not to interfere with the support shaft 22. Therefore, graphics in which a relatively large proportion of recording is performed by line scanning can be easily produced. Photo interrupters 31 are provided on both sides, and when the projections 32 enter, a reverse rotation signal is generated and the carrier 13 moves in the opposite direction.

In the above embodiment, the photoreceptor 12 was described as having a drum shape, but this photoreceptor 12
may be in the form of a film belt made of organic material. The developing method may be any one used in electrostatic photography, such as the cascade method or the fur brush method.
9 is also not limited to a one-component type, but may be a two-component type.

Effects of the Invention As described above, the present invention provides a carrier that reciprocates along the photoconductor with a charging section whose operating range is slightly larger than the height of the characters to be recorded, a developing section, and an exposure section whose height is equal to the height of the characters. As a result, the number of parts installed around the photoconductor can be extremely reduced, which allows the overall size to be reduced.Furthermore, the toner serving as the coloring medium can be used with thermal transfer ribbons, current transfer ribbons, impact transfer ribbons, etc. It is cheaper than commercial film ribbons, etc., and also allows higher density and higher speeds, and produces less noise.

[Brief explanation of the drawing]

FIG. 1 is a vertical side view showing a conventional example, FIG. 2 is a vertical side view showing a first embodiment of the present invention, and FIG.
The figure is a partial front view in the direction of arrow A in Figure 2;
FIG. 4 is a front view showing a second embodiment of the present invention, FIG. 5 is a longitudinal side view thereof, and FIG. 6 is a front view showing the operating range. 12... Photoreceptor, 13... Carrier, 14... Charging section, 15... Exposure section, 16... Developing section, 27... Transfer section, 28... Discharge section, 29... Cleaning section.

Claims (1)

[Scope of Claims] 1. A transfer section, a static eliminating section, and a cleaning section are provided on the outer periphery of the photoconductor, and a carrier is provided that reciprocates along the photoconductor, and each of the carriers has a height that is higher than the height of the character to be recorded. An electrophotographic printer characterized by being equipped with a charging section having a slightly larger operating width, a developing section, and an exposing section equal to the height of characters. 2. Claim 1, characterized in that a charging section and an exposing section are arranged on both sides of the developing section.
Electrophotographic printer as described in section. 3. The electrophotographic printer according to claim 1, wherein respective sets of a charging section and an exposing section are disposed in the digit scanning direction and the row scanning direction with respect to the developing section.