JPH02123375A - Image forming device - Google Patents

Abstract

PURPOSE:To secure a developing gap between a photosensitive drum and a developing part, and positional accuracy in a vertical direction by supporting the developing part and the photosensitive drum with the aid of specified positioning members provided on a main body. CONSTITUTION:The positioning members 13 which are formed with a recessed parts 13a engaged with the developing roll shaft 33 of the developing part 30, and recessed parts 13b and 13c which fixedly keep the developing gap by engaging with pins 27 and 28 formed the both end of a latent image carrier unit 20 and are relatively adjustable light irradiating position by an optical device 21 with respect to the developing part 30 is attached to a main body. Furthermore, these positioning members 13 support the developing part 30 and the latent image carrier unit 20. Thus, the developing gap and the accuracy between the photosensitive drum 29 and the developing part 30 in the vertical direction can surely be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image forming apparatus that forms a toner image on plain paper using an optical image as a signal.

[Conventional technology]

Conventionally, in image forming apparatuses using an electrophotographic method, great efforts have been made to align the photoreceptor drum and the developing device, but this is mainly due to the gap between the photoreceptor drum surface and the developing sleeve, This relates to the so-called developing gap, and Japanese Patent Application Laid-open No. 153670/1983 also describes a method for positioning the same member.

(Problems to be Solved by the Invention) Conventional recording devices using electrophotography do not require relatively fine precision in positioning in the direction perpendicular to the development gap direction. In the system using a support photosensitive drum, strict requirements are placed on the accuracy in the vertical direction since it has a great effect on image quality, and the positioning method has been a major problem.

The present invention was made to solve the above problems, and an object of the present invention is to provide an image forming apparatus that can easily perform vertical positioning using a positioning member.

[Means to solve the problem]

The image forming apparatus according to the present invention maintains a constant developing gap by engaging a recess that engages with the developing roller shaft of the developing section and a pin formed at one end of the latent image carrier unit, and using an optical device. A positioning member in which a recess is formed so that the light irradiation position can be adjusted relative to the developing section is attached to the main body, and the developing section and the latent image carrier unit are supported by this positioning member. It is.

[Effect]

In this invention, a developing gap is ensured by the positioning member, and furthermore, accuracy in the vertical direction between the photosensitive drum and the developing section is ensured.

〔Example〕

FIG. 1 is a schematic side cross-sectional view showing the configuration of an embodiment of the present invention, and FIG. 2 is a perspective view showing the relationship between the main parts of FIG. 1. In these figures, 10 is a main body, inside which a latent image carrier unit 2o, a developing section 30 . Transfer section 40. Fixing section 50° Paper feeding section 60. A cleaning section 70 is provided.

Hereinafter, each of the above parts will be explained in order.

The latent image carrier unit 20 is constructed by integrating an optical printer head 21, which is an optical device, and a photosensitive drum 29. The optical printer head 21 is composed of a large number of linearly arranged LED chips 22 and a convergent light transmission member 23 extending parallel to the LED chips 22 .

There are side plates 24A on both sides of the optical printer head 21.

24B is attached, and a plurality of shafts (three in the figure) 25 are fixed between the side plates 24A and 24B, and support rollers 26 are rotatably provided at both ends of these shafts 25 near the side plates. . A mounting piece 24a is integrally formed on the side plate 24A, and can be fixed to the chassis 11 of the main body 10 through a long hole 24b. Rough side plate 24
A, on the outer surface of 24B, a fulcrum pin 27. A guide pin 28 is fixed (note that the pin 27 on the side plate 24B is not visible).

The photoconductor drum 29 is formed by laminating a transparent conductive layer and a photoconductor layer on a transparent base, and the above-described optical printer head 21 is inserted inside the photoconductor drum 29, and each support roller 26 is attached to the photoconductor from the inside. The drum 29 is rotatably supported. One of the support rollers 26 is provided at a position facing a pressure transfer roller 41, which will be described later. In addition,
The support rollers 26 may be provided not only on both sides of the shaft 25 but also at the center thereof.

The developing section 30 includes a magnet roller 32 . Ear standing regulation plate 34. A stirring screw 35 and the like are provided.

The housing 31 has a protrusion 36, and a coil spring 37 is stretched between the protrusion 36 and the protrusion 12 provided on the chassis 11 of the main body 1o.
The latent image carrier unit 20 is pulled toward the latent image carrier unit 20 by.

Reference numeral 13 denotes a positioning member, and as clearly shown in FIG. 2, a recess 13a is formed in the end surface on the side of the developing section 30, into which the magnet roller shaft 33 of the magnet roller 32 is fitted. On the opposite side of the recess 13a, there is a recess 1 into which the fulcrum pin 27 of the latent image carrier unit 20 is fitted.
3b, and a recess 13c into which the guide pin 28 is similarly fitted,
A guide port 13d is formed continuously. A hole 13e is formed for attachment to the chassis 11 or the like of the main body 10 with screws or the like. Reference numeral 14 denotes a drive roller for rotating the photosensitive drum 29.

FIG. 3 is a diagram illustrating how the positioning member 13 is installed. The fulcrum pins 27 of the side plates 24A and 24B are fitted into the recesses 13b of the left and right positioning members 13, respectively, and the guide pin 28 is fitted into the recess 13c. Both side plates 24A, 24
B is fixed to the chassis 11 using a long hole 24b and a screw 24c. At this time, the installation is performed by aligning the pointer 24d at the tip of the piece 24a with the scale 15 of the chassis 11, rotating about the fulcrum pin 27, and moving the guide pin 28 into the recess 13c.
The latent image carrier unit 20 can be finely adjusted in the vertical direction, that is, in the vertical position, by moving 8 along the vertical direction.

On the other hand, when the magnet roller shaft 33 is inserted into the recess 13a, it is pushed in the direction of arrow A by the coil spring 37 (FIG. 1), so that the positioning member 13 eventually causes the magnet roller 32 and photoreceptor drum 29 to be connected to each other. The interval, that is, the development gap, is automatically constant.

The transfer unit 40 is configured such that a pressure transfer roller 41 is rotatably supported around a support i+h 42. Reference numeral 43 denotes a guide plate, which is configured so that a suction fan 44 gently sucks the unfixed toner on the paper passing through the guide plate so that it is not rubbed and disturbed. 45 is a branch type.

The fixing unit 50 has a halogen lamp of about 850 W installed inside, and is composed of a rotationally driven heating roller 51 and a pressure roller 52 that is in pressure contact with the heating roller 51.
A felt 53 impregnated with silicone oil is provided below the heating roller 51 so as to be pressed by the heating roller 51. 54 is a separation claw, and 55 is a pair of paper discharge rollers.

The pressure roller 52 of the transfer section 40 and fixing section 50
A portion including the driven side (upper side in the figure) roller of the paper ejection roller pair 55 is formed into a unit, and is configured to be able to swing counterclockwise about the support shaft 46 .

The paper feed section 60 includes a paper feed cassette 61, a paper feed roller 62,
It consists of a register roller pair 63 consisting of a drive roller connected to a motor and a rotatable driven roller that is in pressure contact with the drive roller.

The cleaning section 7o includes a cleaning blade 71, and the toner remaining on the photoreceptor tram 29 that has not been transferred by the pressure transfer roller 41 is removed by the cleaning section 70. 80 indicates paper.

Next, the operation will be explained.

Magnet roller 32 and photosensitive drum 29 of developing section 30
A voltage is applied between the photosensitive drum 29 and the transparent conductive layer of the photosensitive drum 29.
Image information is irradiated by the optical printer head 21 and the convergent light transmitter 23 arranged on the inner surface of the photoreceptor drum 29, and a toner image is formed on the corresponding surface of the photoreceptor drum 29.

On the other hand, the paper 80 fed by the paper feed roller 62 is conveyed to the transfer position by the register roller pair 63 after being timed by the register roller pair 63. Transfer section 4
0, the pressure transfer roller 41 is rotated around the support shaft 42, and the photosensitive drum 29 and the pressure transfer roller 4 are rotated.
1 to pinch the paper 80 and transfer the toner image onto the paper 80. The paper 80 on which the toner image has been transferred is separated from the photoreceptor drum 29 by the separation claw 45, and then transferred to the pressure transfer roller 4.
1 and the photoreceptor tram 29 further transport the image to a fixing section 50 . The paper 80 to which the toner image has been transferred in the fixing section 50 is heated and pressed by a heating roller 51 and a pressure roller 52 to fix the toner image, separated by a separating claw 54, and then ejected by a pair of ejecting rollers 55. be done.

〔Effect of the invention〕

As explained above, the present invention maintains a constant developing gap by engaging a recess that engages with the developing roller shaft of the developing section and a pin formed at one end of the latent image carrier unit, and using an optical device. The main body is provided with a positioning member in which a recess is formed so that the light irradiation position can be adjusted relative to the developing section, and the developing section and the photosensitive drum are supported by this positioning member. The positioning member allows you to adjust the development gap between the photoreceptor drum and the development section, as well as
Since positional accuracy in the vertical direction can be maintained, dimensional control is easy and reliability is improved. Furthermore, there is an advantage that the light irradiation position on the developing roller can be set easily and optimally by using the positioning unit.

[Brief explanation of drawings]

FIG. 1 is a schematic side sectional view showing one embodiment of the present invention, FIG. 2 is a perspective view showing the main part of FIG. 1, and FIG. 3 is an explanatory view of the state in which the positioning member is attached. In the figure, 10 is the main body, 11 is the chassis, 112 is the protrusion, 20
b)) Image carrier unit, 21 is an optical printer head,
22 is an LED chip, 23 is a focusing light transmission body, 24A,
24B is a side plate, 25 is a shaft, 26 is a support roller, 27 is a fulcrum pin, 28 is a guide pin, 29 is a photosensitive drum, 30 is a developing section, 31 is a housing, 32 is a magnet roller, 33 is a magnet roller shaft, 34 is a spike regulating plate, 35 is a stirring screw, 36 is a protrusion, 37 is a coil spring, 40 is a transfer section, 41 is a pressure transfer roller, 42 is a support shaft, 50 is a fixing section, 51 is a heating roller, 52 is a pressure application 53 is felt, 54 is a separating claw, 55 is a pair of paper ejection rollers, 60 is a paper feed section, 61 is a paper feed cassette, 62 is a paper feed roller, 63 is a pair of register rollers, and 80 is paper.

Claims (1)

[Claims] a latent image carrier unit including a photoconductor drum having a transparent conductive layer and a photoconductor layer laminated on a transparent substrate; and an optical device for irradiating selected light from the transparent substrate side; In the image forming apparatus, the image forming apparatus includes a developing section disposed opposite to the optical device through a body drum, a recess that engages with a developing roller shaft of the developing section, and a recess formed at one end of the latent image carrier unit. Attaching to the main body a positioning member formed with a recess that engages with the pin, keeps the developing gap constant, and allows the position of light irradiation by the optical device to be adjusted relative to the developing section; An image forming apparatus characterized in that the developing section and the latent image carrier unit are supported by a member.