JPH03132776A - Exposing part soil preventing device for printer - Google Patents

Abstract

PURPOSE:To prevent an air flow orienting in a direction from the surface of a lens from arising between the lens and a photosensitive drum and to prevent dust from attaching to the surface of the lens by generating the air flow that blows into the lens or orients in a direction away from the lens in the vicinity of the surface of the lens in a linear light source array or a linear shutter array. CONSTITUTION:A hose 23 of plural holes 23a is juxtaposed close to the surface of the rod lens array 22c, and is connected to a blower 24 possessing an air filter 24. Consequently, air flow that orients in other direction from the surface of the rod lens array 22c is generated between the rod lens array 22c and the photosensitive drum 21, then no fine dust such paper powder and toner splashing from a developing unit sticks to the surface of the rod lens array 22c.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a device for preventing contamination of an exposure area of an exposure optical system of an electrophotographic printer. Clean airflow that blows onto the lens or moves away from the lens [Industrial field of use] Electrophotographic printers include laser printers and LED
Various products such as printers and liquid crystal printers have been developed. These printers are characterized by high speed, high resolution, and high image quality, and are expected to continue to develop significantly in the future.

The present invention relates to an exposure part stain prevention device for an exposure optical system of an LED printer among the printers described above.

[Conventional technology]

In recent years, as printers have become more sophisticated, the need for color printers has increased. In particular, electrophotography allows for high-speed recording, making it possible to create high-speed color printers.

FIG. 4 shows the configuration of a high-speed color printer using a conventional electrophotographic process. This color printer has four endless image carriers, photosensitive drums la and lb.
, lc, and ld are the four color image recording units U of yellow, magenta, cyan, and black, respectively.
+, Uz, ul.

U4, a recording paper conveyance system 7, and a fixing unit 13.

The color image recording unit Ul includes a charger 2a, an exposure optical system 3a using a light emitting diode LED, a developer 4a, a transfer device 5a, and a cleaner 6a around the photosensitive drum 1a. ing. The other color image recording units U, ~U4 have similar configurations, and I
b, lc.

1d is a photosensitive drum, 2b, 2c, 2d are chargers, 3b,
3c and 3d are exposure optical systems; 4b and 4c;

4d is a developing device, 5b, 5c, and 5d are transfer devices, and 6b.

6c and 6d are cleaners.

The developing units 4a to 4d of each color image recording unit contain developers of different colors.

The developing units 4a, 4b, and 4c each use developers of the three primary colors of yellow, magenta, and cyan necessary for color recording, and the developing unit 4d uses a black developer for black correction.

The recording paper conveyance system 7 includes a paper cassette 8, a pickup roller 9, a chuck conveyance belt 10°10 (the other chuck conveyance belt 10 is not shown), recording paper conveyance belts 11a to llc, and a paper tray 12. It is made up of. The chunk conveyor belts t-io, io are connected to pulleys 14, 1 disposed on both sides of the recording paper to be conveyed in the width direction.
4.15°15 (the other pulleys 14, 15 are not shown). Also, this chuck conveyor belt 10.10 includes a plurality of recording paper chucks (not shown).
are attached at predetermined intervals, and the pulley 15 is connected to a drive system (not shown) on the drive side.

Recording of a color image by the color printer configured as described above is performed in the following manner, as is well known. That is,
The recording paper 16 stored in the paper cassette 8 is delivered to the recording paper conveyance system 7 by the pickup roller 9, and at the same time, a latent image corresponding to each color signal is sequentially formed on each of the photosensitive drums 1a to 1d. The latent image is formed on each photosensitive drum 18 to 1.
This is carried out by uniformly charging the surface of d with corresponding chargers 2a to 2d, and exposing the surface with light using exposure optical systems 3a to 3d. These latent images are developed by the developing units 4a to 4d to become yellow, magenta, cyan, and black color toner images.

A portion of the leading end of the fed-out recording paper 16 is clamped by a recording paper cha-ref attached to the chuck conveyance belt 10, and the chuck conveyance belt 10 and air suction type recording paper conveyance belts lla to llc It is conveyed passing under the photosensitive drums 1a to 1d. At this time, each transfer device 5
The toner images on each of the photosensitive drums 1a to 1d are superimposed and transferred onto the recording paper 16 by a to 5d. After that, recording paper 1
When the recording paper 16 passes through the fixing unit 13, the toner images of each color are fixed, and the fixed recording paper 16 is output onto the paper tray 12. A printer with such a configuration has color image recording units U+ and Uz.

U8. Since U performs the recording operation in parallel to the second pipeline, high-speed color recording is possible.

[Problems to be Solved by the Invention] A color printer having such a configuration is capable of high-speed color recording because each of the color image recording units U+, Uz, 03, and U4 performs a recording operation in parallel to the second pipeline. It becomes.

However, there are problems. This is because toner scattered from the developing devices 4a to 4d, etc. that constitute each color image recording unit, or small dust such as paper dust adheres to the lenses of the exposure optical systems 3a to 3d, and the exposed light reaches the photosensitive drums 1a to 1d. A phenomenon occurs that blocks the Furthermore, the charger 2a~
The ozone generated in 2d attacks the lens surface, causing the lens surface to become cloudy. As a result, the exposure amount decreases and the recording quality deteriorates. To prevent this, it is necessary to regularly clean the exposure optical system.
This poses a problem of tedious work for the operator or increased maintenance man-hours for maintenance personnel.

This invention was devised in view of these problems, and it generates a clean airflow near the surface of the lens of a linear light source array or linear shutter array in a direction that blows onto the lens or moves away from the lens. The purpose of this is to prevent staining of the exposed area by providing a means for cleaning the exposed area.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a printer using a linear light source array or a linear shutter array as an exposure optical system, as shown in FIGS. 1 and 3(A) and 3(B). , an exposure area stain prevention device for a printer, characterized in that means is provided near the surface of the lens 22c of the linear light source array or the linear shutter array for generating an airflow that blows onto the lens or moves away from the lens. That is.

[Effect]

According to the present invention, each airflow is generated by means as described above, which is provided near the surface of the lens 22c of the linear light source array or the linear shutter array, and generates an airflow directed toward the lens or away from the lens. To prevent a phenomenon in which small dust such as toner or paper powder scattered from a developing device constituting a color image recording unit adheres to a lens 22c of an exposure optical system and blocks exposure light from reaching a photosensitive drum.

〔Example] Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1(a) and 1(b) show a first embodiment of the present invention, in which 21 is a photosensitive drum such as an image carrier constituting each color image recording unit, and 22 is each exposing optical system. L
In the ED head, as shown in FIG.
a, the driving element 22b of this LED array, and this LED
It is constituted by a lens, that is, a rod lens array 22c, disposed opposite the tip of the D array 22a. The tip of this rod lens array 22c faces the photosensitive drum 21 with a predetermined distance therebetween.

The present invention provides a means for generating a clean air current that blows onto the surface of the rod lens array 22c or moves away from the surface of the rod lens array 22c, thereby removing toner scattered from a developing device or the like constituting each color image recording unit. This is to prevent small dust such as paper dust from adhering to the surface of the rod lens array 22c and blocking the exposure light from reaching the photosensitive drum 21, and as a means for this purpose,
In the first embodiment, as shown in FIG. 1, a hose 23 having a plurality of holes 23a is connected to a rod lens array 2
2c (located in parallel), and this hose 23 is connected to a blower 25 having an air filter 24.

By doing this, the rod lens array 22
c and the photosensitive drum 21, a rod lens array 22
An air current is generated in the other direction from the surface of the rod lens array 22c, and it is possible to prevent toner scattered from a developing device or the like or small dust such as paper dust from adhering to the surface of the rod lens array 22c.

FIG. 3(A) shows a second embodiment of this invention.
The rod lens array 22 is used as a means for generating an air flow that blows onto the surface of the rod lens array 22c or in a direction that moves away from the surface of the rod lens array 22c.
A cavity 22f with a plurality of holes 22e is formed in the support 22d of the rod lens array 22c so that airflow flows from near the surface of the rod lens array 22c, and a hose 2 is inserted into the cavity 22f.
3 and the other end of this hose 23 is connected to a blower 25 having an air filter 24. With this configuration, assembly man-hours such as hose processing and installation can be reduced.
In addition, a small space near the rod lens array 22c,
− Space can be used effectively.

Further, as shown in FIG. 3(B), the plurality of holes 22e
The same effect can be obtained by using a slit of 22 g instead.

Furthermore, air currents from the surface of the rod lens array 22c in other directions are generated between the rod lens array 22c and the photosensitive drum 21, and small dust such as toner or paper dust scattered from the developing device etc. This can prevent the particles from adhering to the surface of the array 22c.

〔Effect of the invention〕

As explained above, in a printer using a line-shaped light source array or a line-shaped shutter array as an exposure optical system, the present invention provides a method for spraying air onto the lens near the surface of the lens of the line-shaped light source array or linear shutter array. Since a means for generating airflow in the direction away from the lens is provided, between the lens and the photosensitive drum,
Air currents are generated from the surface of the lens in other directions, and the exposed area is prevented from being contaminated by toner scattered from the developing device or small dust such as paper dust, in other words, dust is prevented from adhering to the surface of the lens. This makes it possible to reduce maintenance man-hours for operators or maintenance personnel, and to always obtain stable recording quality.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the exposure section stain prevention device for a printer according to the present invention, FIG. 1(a) is a perspective view, FIG. 2(b) is a left side view, and FIG. A perspective view of an LED head, FIGS. 3A and 3B are perspective views of a second embodiment of the present invention, and FIG. 4 is a configuration of a high-speed color printer using a conventional electrophotographic process. This shows that. 21... Photosensitive drum 22... LED head 22a... LED array 22b... LED array drive element 22c... Rod lens array 22d... Rod lens array supporter 22e...
Hole 22f...Cavity 23...Hose 23a...Hole 24...Air filter 25...Proa.

Claims (1)

[Claims] In a printer using a linear light source array or a linear shutter array as an exposure optical system, the lens (22c) of the linear light source array or linear shutter array is
) A device for preventing contamination of an exposed area of a printer, characterized in that means is provided near the surface of the lens for generating an airflow that blows onto the lens or moves away from the lens.