JPS61223866A - Mechanism for destaticizing specified area of copying machine - Google Patents

Abstract

PURPOSE:To exactly develop an optional effective picture area only, by providing two sets of moving dielectrifying bodies, each of which is provided with at least one destaticizing lamp, along a destaticizing lamp group under moving-free conditions. CONSTITUTION:The titled destaticizing mechanism is composed of a group A of numerous destaticizing lamps (a) which can destaticize the charging potential on the surface of a photosensitive drum 12 over the full width in the direction of the drum axis, two sets of moving destaticizing bodies B and C, each of which is provided with a destaticizing lamp (b) and can separately move along the lamp group A, and partitioning plates (c) for controlling the light projecting area of each lamp (a) and (b). Each of the moving destaticizing body B and C is coupled with a stepping motor M, driving pulley (d), driven pulley (e), and endless wire (f) and the light projecting area of the lamp (b) overlaps the light projecting area of the destaticizing lamp group A. By means of the separate movement of the moving destaticizing bodies B and C, the boundary between the destaticizing area and charging area on the surface of the photosensitive drum 12 can be changed under a stepless condition irrespectively of the size of single bodies of the lamps.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a specific area static elimination mechanism for a copying machine, and more specifically, a static elimination mechanism that includes a large number of static elimination lamps arranged at intervals in the drum axis direction. The group is arranged so that it can emit light over the entire width of the image area of the photosensitive drum, and a partition plate is provided between each static elimination lamp to define the emission area of each static elimination lamp. The present invention relates to a specific area neutralization mechanism for a copying machine that eliminates potential in a specific area of a drum surface.

(Prior Art) Conventionally, in order to control the charged area on a photoreceptor formed by a charging device, it has been known to remove unnecessary charges using light irradiation from a static elimination lamp.

Conventionally, a plurality of static elimination lamps are arranged in a straight line, and the static elimination lamps are installed in a static elimination lamp housing whose light irradiation area is regulated by a partition plate to form a static elimination mechanism, and this is fixed to the main body of the copying machine. This is the place that was set up.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional static elimination mechanism, there is a limit to miniaturization due to the structure of the lamp alone. Another drawback is that it is not possible to identify the area where a latent image is formed on the photoreceptor by blinking a static elimination lamp corresponding to a specific area of the document regardless of the magnification.

The present invention was devised in view of the above-mentioned circumstances, and aims to eliminate the above-mentioned drawbacks through simple improvements.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a specific area static eliminator for a copying machine described at the beginning, in which two sets of movable static eliminators each having at least one static eliminator lamp are provided. The lamps are characterized in that they are individually movable along the group of static elimination lamps.

(Function) According to the above-described characteristic configuration, the boundary between the charged area and the neutralized area on the drum surface can be changed and set steplessly by changing the position of the movable neutralizing body corresponding to the static eliminating lamp group.

(Embodiment) Hereinafter, an embodiment of the present invention will be described based on the drawings. FIG. 3 shows the entire copying machine of the so-called center reference type, and in the figure, reference numeral 1 indicates a contact glass 2 and a document presser 3 on the top.
In the main body of the copying machine, an exposure device 5 with a movable optical system is disposed in an upper space partitioned by a partition plate 4.

The exposure device 5 includes a light source 6 and first to fourth reflecting plates 7 to 10.
and a condensing lens 11, and the condensing lens 1
The position of the lens 1 can be changed steplessly in the direction of the optical path, and exposure can be performed by a so-called zoom mechanism for magnification and reduction.

Next, 12 in the figure is a photosensitive drum, and a charging device 13
, specific area static elimination mechanism 14, developing device 15, transfer device 16
, a copy paper separating device 17, and a cleaning device 18 are arranged in this order in the drum rotation direction R.

Reference numeral 19 designates a loading section of the cassette case 2o, 21 a paper feed conveyance device, 22 a paper discharge conveyance device, 23 a heat fixing device, 24 a pair of paper discharge rollers, and 25 a tray.

Next, based on FIGS. 1 and 2, the specific area #,
To explain a specific example of the mechanism 4, this one can eliminate the electric potential of the drum surface in the drum axial direction by projecting light onto the drum surface that grows after the photosensitive drum surface is charged by the charging device 13. A group A of a large number of static eliminator lamps a, and two sets of movable static eliminators B each having one static eliminator lamp b that is individually movable along the static eliminator group A.
.

C, and a partition plate C for defining the projection area of each lamp a, b.More specifically, the static elimination lamp group A is fixedly provided on the copying machine main body l, and the static elimination lamp group a
are arranged at predetermined intervals in the drum axis direction.

On the other hand, each movable static eliminator B, C is connected to an endless wire f wound around a driving pulley d and a driven pulley e attached to a stepping motor M, and is connected to an endless wire f wound around a driving pulley d and a driven pulley e attached to a stepping motor M. are provided so as to overlap the light emitting area of the static elimination lamp group A.

According to the above configuration, there is a charging mode in which all of the static elimination lamps a and b are turned off, and among the static elimination lamp group A: Hatake:llll
By appropriately selecting and setting the forms of ζ body 4, 2 umbrellas, R4, and 18, the range of the photosensitive drum 12 can be electrically charged. In addition, when making a partial copy, the boundary T between the lit charge eliminating lamp a1 indicated by the O mark in FIG. 2 and the unlit charge eliminating lamp a8 indicated by the X mark in FIG. By changing the position of C in the drum axis direction, the width of the partial copy can be arbitrarily set in the drum axis direction.

Alternatively, partial white copying can be performed by controlling the front self-discharge lamp a to turn on and off in reverse. That is,
For example, in Fig. 2, among the static eliminating lamps indicated by a, the ones marked with X are turned on, the remaining static eliminating lamps marked with ○ are turned off, and the static eliminating lamps b and b of movable static eliminators B and C are turned on. By eliminating the potential on the drum surface between the movable static eliminators B and C, it is possible to make a partially white copy corresponding to the width.

Of course, the width of this partially outlined copy can be changed and set as desired.

The width control in the direction of movement of the optical system for partial copying and whiteout copying described above is performed by controlling the lighting of all the necessary lamps a and b, as in the prior art.

(Effects of the Invention) As explained above, according to the specific area static elimination mechanism of the present invention, by moving the two sets of movable static eliminators separately, the boundary between the static neutralization area and the charged area on the drum surface is adjusted to the size of a single lamp. In addition, the width between the boundaries can be set and changed arbitrarily, and the so-called center, which aligns the center of the width of the document with the center of the inside of the contact glass, can be changed steplessly. Regardless of whether it is a reference type copying machine or a one-end reference type copying machine that aligns the original on two adjacent sides of the contact glass, it is possible to use only the arbitrary effective image area when changing magnification, partial copying, or outline copying. It has become possible to perform proper development, and in turn, it has become possible to eliminate wasteful toner consumption and unnecessary transfer in the form of black streaks.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a specific area static elimination mechanism, FIG. 2 is an explanatory diagram of partial copying, and FIG. 3 is a schematic sectional view of the entire copying machine. a, b... Static eliminator lamp, C... Partition plate, A... First static eliminator lamp group, B, C... Moving static eliminator. Figure 2 Figure 3

Claims (1)

[Claims] A group of static eliminating lamps arranged at intervals in the direction of the drum axis is provided in a state where they can emit light over the entire width of the image area of the photosensitive drum, and a partition is provided to define the light emitting area of each static eliminating lamp. A specific area static elimination mechanism for a copying machine, in which a plate is provided between each static elimination lamp, and the electric potential in a specific area on the surface of a photosensitive drum is eliminated by blinking control of the static elimination lamp, wherein two sets each have at least one static elimination lamp. A specific area static eliminator mechanism for a copying machine, characterized in that movable static eliminators are separately provided movably along the static eliminator group.