JPS6143760A - Controller of electrification range - Google Patents

Abstract

PURPOSE:To electrify only a required area corresponding to a set magnification by providing plural long holes different in length on the outside peripheral part of a charging charger and turning the charging charger in accordance with movement of a lens unit of variable power conversion. CONSTITUTION:Long holes 10a, 10b... different in length are provided on the outside peripheral part of a conductive pipe 9, and a gear 9a is provided in the end part of the pipe 9. The gear 9a is turned by an interlocking mechanism consiting of a lever 17, a slide pin 19, a supporting shaft 16, a hole part 15a of a lever 15, and a pin 18 provided on a lens holding base 3a. When a lens 3 is slid along a lens base rail 3b in the direction of an arrow B, the lever 17 is slid in the direction of an arrow F by the interlocking mechanism, and the gear 9a is turned in the direction of an arrow G to switch long holes 10a, 10b.... Thus, only the part corresponding to the width of the set magnetificaton corresponding to the position of the lens 3 is electrified with the simple structue to reduce the cost.

Description

[Detailed Description of the Invention] [Technical Field] This invention aims to change the charging range of a photoconductor according to the conversion magnification during magnification conversion copying in a copying apparatus that performs copying by creating an electrostatic latent image on a photoconductor. The present invention relates to a charging range control device to be changed.

<Prior art and its drawbacks> A photoreceptor is charged in advance and an electrostatic latent image is formed by exposing areas other than the image area, and toner charged with the opposite charge to the photoreceptor is attracted to the electrostatic latent image. Copying machines that use a copying device that visualizes images by making images visible are now widely available. Furthermore, recently, many of the above-mentioned copying machines have been commercialized that have a magnification change copying function for enlarging or reducing the original document onto copy sheets of different sizes. In such a copying machine, the width of the image formed on the photoreceptor changes depending on the set conversion magnification for enlargement or reduction. For this reason, the width of the photoreceptor in the direction perpendicular to the copy paper feeding direction is set to the maximum image width to be formed. Therefore, when the width of an image formed during reduction copying is short, a non-image forming area occurs on the photoreceptor.

Since no electrostatic latent image is formed in this non-image forming area,
There is no need to perform charging.

For this reason, conventional methods have been used to adjust the charging width to the range where an image is formed by cutting off the charging on the non-image (graphical acid) part of the photoreceptor.As a means of achieving this, there is a device that can be rotated around the outer periphery of the charger. There is a type of quadriconductor vibrator that has a plurality of elongated holes each having a different length.The plurality of elongated holes each have a width corresponding to the conversion magnification, and the conductive pipe is The long hole corresponding to the set conversion magnification is rotated so as to face the photoreceptor drum.This allows only the image forming area of the photoreceptor to be charged.

However, the above-mentioned conventional means uses a solenoid as a rotational drive device for the conductive pipe, which has the disadvantage of increasing costs.

<Object of the Invention> In view of the above-mentioned disadvantages, an object of the present invention is to provide a charging range control device that enables a conductive pipe to be rotated without using a solenoid, thereby realizing adjustment of the charging range of a photoreceptor at low cost. It is to be.

<Configuration and Effects of the Invention> In summary, the present invention provides a charging range control device with a rotational force that extracts the displacement due to the movement of the lens unit related to the operation of the magnification conversion copying function as a rotational force and transmits this to a conductive pipe. It is characterized by being equipped with a transmission device.

According to the present invention configured as described above, there is no need to use a solenoid as a rotation drive device for the conductive pipe used in the charging range control device, and the charging range of the photoreceptor can be adjusted in accordance with the conversion magnification at low cost. There are benefits that can be realized.

<Embodiment> FIG. 2 is a sectional view showing a schematic structure of a copying machine using a charging range control device according to an embodiment of the present invention.

A photosensitive drum 4 is disposed in the center of the copying machine main body l. A charging charger 2 having a conductive pipe according to the present invention supported on its outer periphery is installed above the photosensitive drum 4, and a portion of the photosensitive drum 4 facing the charger 2 is charged by corona discharge during the charging process. . Thereafter, an electrostatic latent image is formed in the exposure process in which reflected light 7' of the optical system light st 7 from the original is distributed, and further developed in the development process in which toner is supplied from the developing device 5. Ru. Next, in a transfer process, the image is transferred onto the transported copy paper, and is electrically neutralized in a static elimination process. Further, the photosensitive drum 4 rotates in the direction of arrow A in synchronization with the scanning of the optical system and the conveying operation of the copy paper. As a result, the steps of charging, exposure, development, transfer, and neutralization proceed in sequence on the surface of the photoreceptor drum. A lens 3 is installed above the charger and is held by a lens base, and the lens 3 is placed in the direction of arrow B or C depending on the set conversion magnification.
move in the direction.

FIGS. 3A and 3H are schematic diagrams of a conductive pipe of a charging range setting device according to an embodiment of the present invention.

As shown in the sketch of FIG. 3(A), the charger 2
A j17 conductive pipe 9 is supported. This pipe 9
is made of a cylinder made of a highly conductive metal.
A long hole whose longitudinal direction is in the axial direction is formed in its outer peripheral surface. As shown in the cross-sectional view of FIG. 3(B), this elongated hole 1
0a to 10d are provided at four equal intervals around the axis of the conductive pipe 9, and each has a length corresponding to a different conversion magnification. Further, a rotating gear 9a is attached to one end of the conductive pipe 9, and rotational force is transmitted by a rotational force transmission device described later.

FIG. 4 is a diagram showing a support structure for a conductive pipe in a charging range control device according to an embodiment of the present invention. On both sides of the photoreceptor 4, conductive frames 21 and 22 are arranged parallel to the side surface of the photoreceptor. and are fixed to the main body at positions not shown. A high voltage transformer 23 is fixed to the left frame 21, and its socket terminal 23a passes through a hole 21a formed in the frame 21 in the direction of the charger 2. One end of the charger 2 is inserted into the socket terminal 23a, and a charger holder 24 formed at the other end is engaged with a hole 25 formed in the frame 22. As a result, the charging charger 2 is fixed to the main body of the copying machine. Frames 21 and 22
Flanges 26 and 27 formed of a conductive material are fixed at positions corresponding to both ends of the charger 2 . The outer diameter of the flanges 26, 27 is approximately equal to the inner diameter of the electrically conductive pipe 9, and both ends of the conductive pipe 9 are rotatably fitted onto the flanges 26, 27. Thereby, the thermoelectric pipe 9 is grounded by the flange 26.27 and the frame 21.22. Further, a contact piece 29 is provided protruding from the end of the charger 2 on the side of the holder 24, and by contacting the flange 27, the charger 2 and the conductive pipe 9 are electrically connected.

With the above-described configuration, only the elongated hole portion of the discharge from the charger 2 in the direction of the photoreceptor drum 4 reaches the photoreceptor, and the portion other than the elongated hole is short-circuited to the conductive pipe 9 and does not reach the photoreceptor drum 4.

FIG. 1 is a diagram showing a schematic structure of a rotating force transmission device of a charging range control device according to an embodiment of the present invention. .

The lens 3 is fixed to a lens base 3a, and the lens base 3a is movable on a rail 3b. Further, a wire 11 is fixed to this lens base 3a by a wire fixing fitting 13, and the driving force of a motor (not shown) is transmitted thereto. The connecting rod 15 is rotatably supported by a support pin 16 fixed to the main body of the copying machine. Holes 1 are provided at both ends of the connecting rod 15.
5a and 15b are opened, and the lens side hole 15a engages with a guide pin 18 protruding from the lens base 3. The other rack gear side hole 15b engages with a guide pin 19 projecting from the top of the rack gear. These guide pins 18 and 19 are connected to the respective holes 15a and 1.
5b, and is sized to be able to move freely in the longitudinal direction of the hole. The rank gear 17 meets a rotating gear 9a fixed to one end of the electric pipe 9, and the linear motion of the rank gear 17 is converted into the rotational movement of the four electric pipes 9.

The operation of the transmission device configured as described above is reduced by a magnification change t*
An explanation will be given below using +g shooting as an example.

When the reduction magnification is set by the operator, this set magnification is sent to CP [J of the copying machine, and a motor (not shown) is driven to move the position of the lens 3 to a position corresponding to the set magnification. By driving this motor, the wire 11 is moved in the direction of arrow B, and the lens base 3a to which the lens 3 is fixed is moved in the direction of arrow B. This movement of the lens base 3a in the direction of arrow B is transmitted to the connecting rod 15 by the guide pin 18 and the hole 152, and the connecting rod 15 is transferred to the support pin 16.
Rotate in the direction of arrow E around . This rotation is caused by the hole 15b.
and is transmitted to the kura and kugya 17 by the guide pin 19,
The guide gear 17 moves in the direction of arrow F and rotates the engaged rotary gear 9a in the direction of arrow G. Through the above-described series of operations, the movement of the lens 3 is transmitted to the four-electroconductive pipe 9 as rotational force, and when setting the reduction magnification, the electroconductive pipe 9 is rotated so that the elongated hole facing the photoreceptor becomes shorter. Further, when setting the magnification, the conductive pipe 9 is rotated so that each part constituting the transmission device moves in the opposite direction and the elongated hole facing the photosensitive drum 4 becomes longer. As a result, the support pin 16 and guide pin 18, 19 of the connecting rod 15 are adjusted so that the amount of movement of the lens 3 and the amount of rotation of the elongated hole of the four-electrode pipe 9 correspond to the amount of movement of the lens 3 according to the set magnification. By adjusting the distance, it becomes possible to make the elongated hole in accordance with the set magnification face the photoreceptor.

On the other hand, high voltage is applied to the charger 2 from the high voltage transformer 23, and only the area of the photosensitive drum 4 facing any of the long holes 10a to 10d of the conductive pipe 9 is charged.

In addition, by using a constant voltage drive method for the high voltage power supply mentioned above,
The surface potential of the charged range of the photosensitive drum 4 is always maintained in a constant and stable state regardless of changes in the area of the range. As a result, a high-quality image can always be obtained at any conversion magnification.

In addition, when driving the high voltage power supply with constant current, as shown in Figures 5 and 6, the control circuit of the pressure unit uses signals S2 and Sa (S+ is the power on/off signal) corresponding to the set conversion magnification. 31 and a corresponding output is applied to the middle jar 2), it is possible to obtain the same effect as the constant field drive method (i.
jJ Noh.

Furthermore, there is no problem if the dummy pipe is made of a conductive material other than metal, especially as shown in Figure 7.
If the charger 2 is made of electrically conductive rubber 9', the life of the charger 2 can be increased and the space in the radial direction can be reduced. This makes it possible to narrow the distance between the photoreceptor and the charger, thereby reducing the output of the high-voltage power supply and reducing power consumption.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic structure of a rotating force transmission device of a charging range side 9z11 device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a schematic structure of a copying machine using the same charging range control device. 3(A) and 3(B) are diagrams showing the schematic structure of the conductive pipe of the charging range control device, and FIG. 4 is a diagram showing the support structure of the conductive pipe. 5 and 6 show an Ig+ control method when driving a high-voltage power supply of a copying machine with constant current using an embodiment of the present invention, and FIG. 7 shows another embodiment of the conductive pipe according to the present invention. FIG. 2-electrostatic charger, 3-lens, 4-photosensitive drum, 9-conductive pipe, lOa~10d
-Long hole, 15 series rondo, 17-rasok gear.

Claims (2)

[Claims] (1) In a charging range control device in which a conductive pipe having a plurality of elongated holes of different lengths in the axial direction is rotatably supported on the outer periphery of a charging charger, a lens related to the operation of magnification conversion is used. A charging range control device comprising a rotational force transmission device that extracts displacement due to movement of the unit as rotational force and transmits the rotational force to the conductive pipe. (2) The rotation force transmission device rotates the conductive pipe so that the width of the long hole facing the photoreceptor becomes shorter or longer when the lens unit moves in a direction to reduce or enlarge the image. The charging range control device according to claim 1, which is a rotating force transmission device.