JPS6052882A - Electrophotographic printer - Google Patents

Abstract

PURPOSE:To decrease the parts to be disposed around a photosensitive body and to reduce the size of a printer by mounting an electrostatic charge part, exposing part and developing part to a carrier which moves back and forth along the photosensitive body and performing electrostatic charge, optical writing and development for each line. CONSTITUTION:A carrier 13 provided freely movable back and forth below a photosensitive body 12 is successively arranged with an electrostatic charge part 14, an exposing part 15 and a developing part 16. The part 14 is constituted of a shielded Corotron electrifier in which the length of a discharge wire is set slightly larger than the height of the character to be printed. When the carrier 13 moves rightward, the body 12 is charged electrostatically by the part 14 and an LED array 18 is driven according to an image signal. The body 12 is then exposed through a near convergent rod lens array 17 and an electrostatic image is formed thereon. A pulley 24 is rotated by a wire 25 in parallel with the movement of the carrier 13 and apermanent magnet roller 21 supplies a toner 19 to the surface of the body 12. As the carrier 13 moves in one direction, the sensible image for one line is formed in the above-mentioned way. The carrier 13 returns to the home position after the body 12 rotates by one line.

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 thereof 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) by a corotron charger whose width matches the width of the photoreceptor (1) is attached to a part of the outer circumference of the photoreceptor (1). It is provided. Further, the photoreceptor (1)
An exposure device (3) that reciprocates in the generatrix direction 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) stores a permanent magnet roller (7) in a container (6) that holds toner (5), and the electrostatic latent image formed by the exposure device (3). Visualize.

Furthermore, a corotron transfer device (8) is placed above the photoreceptor (1).
) is provided, and the toner (
5) The toner image is completely adhered and the toner image is fixed by a fixing device (not shown). Next, the photoreceptor (1) is removed by the static eliminator α1.
The entire surface of the toner is irradiated with light to erase electrostatic afterimages and remove residual toner by a cleaning device αυ.

In this way, the photoreceptor (1) is intermittently fed every t rows, and the exposure device (3) is driven every every row, and the transfer paper (9) is moved intermittently every t rows.
Image information is formed in 9). In such a configuration, a charging section (2), an exposure device (3), a developing device (
4) Each process part, such as the corotron transfer device (8), static eliminator α0, cleaning device αη, etc., is arranged in a satellite shape around the outer circumference of the photoreceptor (1), which makes the device extremely large and difficult to use as a printer. is an unsuitable structure.

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

Summary of the Invention The present invention has a charging section, an exposing section, and a developing section mounted on a carrier that reciprocates along a photoreceptor, and performs 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 arranged around the trap, and it can also be made lighter.

Embodiment of the Invention A first embodiment of the present invention will be described with reference to FIGS. 2 and 3. First, a drum-shaped photoreceptor (2) is provided, and this photoreceptor α2 is connected to a drive device (not shown) so as to be intermittently fed row by row in a counterclockwise direction. A carrier αj guided by a guide shaft (not shown) is provided below the photoreceptor (6) so as to be able to reciprocate. This carrier α3 includes, from the right side, a charged part α4, an exposed part Q5,
Developing units αQ are arranged in sequence.

The charging section C14 is constituted by a shield type corotron charger in which the length of the discharge wire is set slightly larger than the height of the characters to be printed. Further, the exposure section QCJ includes a focusing rod lens array α7) and an LE
This is related to the combination with D array〇al. moreover,
The developing section αQ includes a toner container t that stores toner α.
nt, and a permanent magnet roller (c) whose outer peripheral surface is kept at a constant distance from the surface of the photoreceptor a' is provided inside the toner container (a). This permanent magnet roller (
C) is fixed to the end of the support shaft passing through the toner container 0!0, and this support shaft is supported by a bearing), and a pulley (C) is fixed to the other end. A wire (E) with both ends fixed is wound around the pulley (C) K.

Further, around the photoreceptor (2), there are arranged a transfer section gradient through which the transfer paper (c) passes, a static eliminator '4s@, and a cleaning section fence.

In such a configuration, the carrier α3 reciprocates while the photoreceptor α force is stopped, but 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 αj moves to the right, the photoreceptor oi is charged at the charging part α◆, and I and H are charged according to the image signal.
The D array (to) is driven and exposes the photoreceptor (lI2) through the focusing rod lens array αη to form an electrostatic latent image. For example, the surface of the photoreceptor (2) is charged to +400V by the charging section 4. At the exposed point of the photoreceptor Q), 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 α8, toner (corresponding to the electrostatic latent image) adheres to the surface of the photoreceptor υ and is visualized. That is, as the carrier (to) moves, the pulley (c) is rotated by the wire (c), and the permanent magnet roller Qυ supplies toner αI' to the surface of the photoreceptor Q2. At this time, the length of the spike of toner α is controlled to a constant height by a doctor (not shown).

In this way, by moving the carrier Q3 in one direction, the visible portion is visualized, and the carrier αj returns to its original position after the photoreceptor α2 rotates by the same amount.

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, an exposure section αυ and a charging section α→ are provided on both sides of the developing section 0Q. Thereby, optical writing and development are possible in any case when the carrier αj is reciprocating. Therefore, speeding up can be achieved.

In addition, the permanent magnet roller (c) is moved by a motor (to), and the exposed part aO and the charged part α→
and. The exposing section Q5 and the charging section a4 are arranged obliquely so as not to interfere with the support shaft (2). Therefore, it becomes easy to create graphics in which the proportion of recording by line scanning is relatively high. Photointerrupters 0 and 0 are provided on both sides, and when the projecting piece 0'4 enters, a reversal signal is generated and the carrier (2) moves in the opposite direction.

In the above embodiment, the photoreceptor (6) is described as having a drum shape, but the photoreceptor α2 may be a film belt-like member made of an organic material. and,
Development methods include static, such as cascade method and fur brush method.
Any toner used in photographic methods may be used, and the toner is not limited to a one-component type, but may be a two-component type.

Effects of the Invention As described above, the present invention is equipped with a charging section whose operating range is slightly larger than the height of the characters to be recorded on a carrier that reciprocates along the photoreceptor, a developing section, and an exposure section whose height is equal to that of the characters. As a result, the number of parts installed around the photoreceptor can be extremely reduced, which allows the overall size to be reduced.Furthermore, the toner serving as the coloring medium can be used for thermal transfer ribbons, electrical transfer ribbons, and impact transfer ribbons. It is cheaper than film ribbons, etc., can be made higher in density and faster, and has lower noise.

[Brief explanation of drawings]

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. 3 is a partial front view in the direction of arrow A in FIG. FIG. 4 is a front view showing the second embodiment of the present invention, FIG. 5 is a vertical side view thereof, and FIG.
The figure 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...Static elimination section, 29...Cleaning section Applicant: Tokyo Electric Co., Ltd.

Claims (1)

[Claims] 1. A transfer section, a static elimination section, and a cleaning section are provided on the outer periphery of the photoreceptor, and a carrier that reciprocates along the photoreceptor is provided, and on this carrier, the height of each character to be recorded is lower than the height of the character to be recorded. An electrophotographic printer is characterized in that it is equipped with a charging section, a developing section, and an exposing section having a slightly larger operating width, and an exposing section equal to the height of characters. 2. The electrophotographic printer according to claim 1, wherein a charging section and an exposing section are arranged on both sides of the developing section. 3. The electrophotographic printer according to claim 1, wherein respective sets of a charging section and an exposing section are arranged in the digit scanning direction and the row scanning direction with respect to the developing section.