JPS6340172A - Picture recorder - Google Patents

Abstract

PURPOSE:To execute mutual positioning with high accuracy, and also, to reduce a vibration by assembling an image forming part and its light source to a body block which is formed as one body with a synthetic resin, and positioning and attaching its body block and a fixing device, etc. to a chassis of a body device. CONSTITUTION:As for a process cartridge 10, four devices of a drum type electrophotographic photosensitive body 15, an electrifier 16, a developing device 17, and a cleaning device 18 are formed to a cartridge,and it is brought to an inserting/detaching operation to and from a prescribed position of the upper housing B along a guide rail 17 provided on the upper housing B side, in a state that the upper housing is open. A feed paper part for feeding transfer paper P, and its light source (laser unit 9) are assembled to a body block 30 which is formed as one body with a synthetic resin, and its body block (block structure body) and a fixing device, etc. are positioned and attached to a chassis of a body device. In such a way, an image forming part and a feed paper mechanism, and also, the fixing device, etc. can be positioned mutually with extremely high accuracy, therefore, the alignment executed satisfactorily, the rigidity of a frame is also improved, and a vibration can also be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention [Field of Industrial Application] The present invention relates to an image recording device, particularly an electrophotographic image recording device.

[Conventional technology]

As one of the structural forms of this type of equipment, in order to facilitate maintenance and inspection of the equipment, the equipment is divided into a northern part and a lower part, and the upper part can be opened and closed freely with respect to the lower part using a hinge. For example, the lower part contains a paper feed means, image transfer means, paper transport means, fixing means, paper ejection means, etc., and the upper part contains a process cartridge (image forming part), its holding means, etc.
A light source means (exposure light source means such as a laser scanner) is incorporated, and by opening and raising the upper part from the lower part around a hinge, the inside of the apparatus is wide open and maintenance and inspection of the inside of the apparatus can be carried out.

[Problem that the invention seeks to solve]

However, in such an apparatus, since the upper and lower parts of the apparatus are independent, alignment is difficult, and the position of the paper and image may be twisted, shifted, or tilted, especially in the transfer section. In addition, if the side plates of sheet metal are opposed to the chassis of the main unit and connected with stays, the side plates may twist or tilt, making it difficult to improve the precision of the frame, and the sheet metal frame may resonate with the drive system. This may also cause image defects.

The object of the invention is to solve the above-mentioned problems.

Summary: Structure of the Invention [Means for Solving the Problems] The present invention provides a paper feeding unit that feeds transfer paper, an electrophotographic image forming unit, and its light source, which are integrally molded from synthetic resin. The object of the present invention is to provide an image recording apparatus characterized in that the main body block is assembled to a main body block, and the main body block, a fixing device, etc. are positioned and attached to the chassis of the main apparatus.

[For production]

The present invention involves positioning and assembling at least a paper feeding mechanism from paper feeding to transfer, a light source, and an image forming section to a three-dimensionally structured main body block, and the main body block, a fixing device, and a paper feeding mechanism from transfer to fixing. By positioning and attaching the paper conveyance guide and the like to the chassis of the main unit, the image forming section and the paper feeding mechanism, as well as the fixing device and the like, can be positioned relative to each other with extremely high precision, so that good alignment can be achieved. Additionally, the frame has high rigidity and vibrations can be reduced.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below using an electrophotographic image recording apparatus that records images by scanning a photoreceptor with a laser beam.

(1) Overall configuration of the device (Figures 1 and 2) A-B are the lower casing and upper casing of the device, and the upper casing B opens and closes around the hinge part 1 relative to the lower casing A. freely connected,
It is always biased in the opening direction by a biasing spring (not shown). When the upper part body B is opened and fully closed against the lower case A against the biasing spring, the locking member engages and the upper part body B is held in the closed state against the lower case A. be done. FIG. 1 shows this confinement state.

When the locking member is released, the upper writing brush B opens with respect to the lower housing A around the hinge part 1 and is rotated open by the biasing force of the biasing spring to a predetermined diagonally upward open posture position or approximately vertical. held in the position it was in. FIG. 2 shows this open state. In this open state, the inside of the apparatus is open, and internal inspection, insertion and removal of process cartridges, etc. can be easily performed.

On the lower text A side, there is a paper feed section 5 consisting of a paper cassette 2, a paper feed roller 3, a registration roller 4, etc., and an image transfer discharger 6.
, a paper conveying section 7, an image fixing device 8, a laser unit 9, etc. are provided. On the upper body B side, a process cartridge 10, a laser reflection mirror 11, a pre-exposure lamp 12, a paper transport section 13, a paper discharge tray 14, etc. are arranged.

In this example, the process cartridge 10 is made up of four devices: a drum-type electrophotographic photoreceptor (hereinafter referred to as drum) 15, a charger 16, a developer 17, and a cleaning device 18, as shown in the upper part of the second figure. When the part body B is open, it is inserted into and removed from a predetermined position of the upper housing B along the guide rail 17 provided on the upper housing B side.

Image recording is performed in the state shown in FIG. 1, in which the process cartridge 10 is mounted on the upper housing B side and the lower housing B is closed and locked in the lower housing A.

That is, in response to the image recording start signal, the drum 15 is rotated around the shaft 15a in the direction of the arrow at a predetermined circumferential speed.

The drum 15 has a pre-exposure lamp 1 on its circumferential surface during its rotation process.
2, and then uniformly charged with positive or negative electricity by a charger 16.

Next, in the exposure section 19, the laser beam scanning unit 9 performs laser beam scanning exposure to form an electrostatic latent image of the target image on the peripheral surface.

The laser beam unit consists of a semiconductor laser (not shown), a rotating polygon mirror, an f-0 lens, etc.
A laser beam modulated in accordance with the time-series electric pixel signals of the target image is outputted from the semiconductor laser to the rotating polygon mirror, and is transmitted to the exposure section 1 of the drum 15 via the reflection mirror 11.
9, the surface of the drum 15 is exposed to laser beam main scanning in the drum generatrix direction.

The electrostatic latent image formed on the drum 15 is developed with toner by a developing device 17, and reaches the position of the image transfer discharge device 6. The toner developed image is then sequentially transferred from the paper feeding section 5 onto the surface of the transfer sheet 9 fed between the drum 15 and the transfer discharger 6 in synchronization with the rotation of the drum 15.

The transfer paper on which the toner image has been transferred is sequentially separated from the surface of the drum 15 by a separating member (not shown), introduced into the image fixing device 8 via the paper transport section 7, where the image is fixed, and then discharged via the paper transport section 13. The image is discharged onto the paper tray 14 as an image-formed product.

The surface of the drum 15 from which the transfer paper has been separated is cleaned in a cleaning section and used for repeated image formation.

The paper feed unit 5 includes a paper cassette 2 loaded with paper p, a half-moon-shaped (broken-circle) paper feed roller 3. It consists of 4 registration rollers, etc. The paper feed roller 3 is intermittently rotated in the paper feeding direction by one rotation or a predetermined number of rotations at each predetermined paper feeding timing, and each of the intermittent rotations directs one sheet of paper P in the cassette 2 toward the registration roller 4. sent out.

The paper P fed one sheet from the cassette 2 by the paper feed roller 3 has its leading end caught by the nip of the registration roller 4, which is stopped at that time, and is then transferred to the drum 1.
The registration roller 4 is driven to rotate at a predetermined timing synchronized with the rotation of the image forming apparatus 5, and is fed toward the transfer unit 6.

(2) Main body block (Figures 3 and 4) In accordance with the present invention, the apparatus of this example has a paper feed section 5 that feeds transfer paper (paper) P and its light source (laser unit 9) made of synthetic resin. Assembled into the integrally molded main body block 30,
It has a structure in which the main body block (block structure), fixing device, etc. are positioned and attached to the chassis of the main apparatus.

Figure 3 shows the chassis of the main unit (chassis 2 of lower case A).
FIG. 4 shows a perspective view of only the main body block 30.

The main body block 30 of this example is made of modified PPo or flame retardant ABS.
It is a three-dimensional injection molded product made of synthetic resin mixed with 20 to 40% glass fiber or inorganic fiber, and is made with low foaming during injection molding. As a result, the wall thickness can be reduced to approximately 5ffi, and dimensional accuracy is improved due to increased rigidity.

As shown in the fourth figure, the main body block 30 has the following parts.

a. Guide rails 31 and 32 for mounting the paper cassette 2 and receiving stopper 33 b. Bearing 3a of the paper feed roller unit including the paper feed roller 3
a groove 34 and a bin hole C for positioning and receiving the paper feed drive motor unit 21, a positioning bin 36d for mounting the paper feed drive motor unit 21, a paper feed guide plate 22-23, a registration roller 4,
A registration roller bearing 4 that positions a registration unit composed of transfer guide plates 24 and 25 in the paper advancing direction.
A groove 37 for positioning and receiving a, a bin 38e for positioning in the width direction, a positioning bin 39f for the transfer guide unit including the image transfer discharger 6, a positioning bin 40g for the high-pressure cast 26, and a two-part rod. In a state where body B is confined against lower housing A,
A bearing groove 41 for receiving the drum shaft 15a of the process cartridge 10 mounted on the upper housing B side, a seat surface 42h for positioning the laser beam return reflection mirror 11, a bearing hole 1 for the drive gear G that drives the drum 15, and a process The rotational direction of the cartridge 10, the positioning hole 45k of the laser unit 9 which is the light source for image formation, and the installation of the locking mechanism unit 27 that locks the upper housing B enclosed in the lower housing A are as follows: Positioning bin 46 Are the above-mentioned parts 31 to 40 and 42 to 46 at mutual heights based on the position of the bearing groove 41 of the drum shaft 15a? 1 (The fF unit is installed at a surface position) and the spacing dimensions etc. are accurately set and formed. Such a structure with good dimensional accuracy can be easily mass-produced by the above-mentioned resin injection molding method.

As shown in the third figure, a paper feed roller unit (a) and a motor unit (a) (c) 21. d registration unit, e transfer guide unit, f high pressure unit 26, h drum drive gear G,
j laser unit 9. By positioning predetermined members such as the locking mechanism unit 27 and assembling them with screws or the like, the mutual positional accuracy between the assembled units and members constituting the block structure becomes accurate.

The above-mentioned block structure is directly positioned on the chassis 20 of the upper casing A as the chassis of the main device using the positioning pin 28 and its insertion hole, and is removably attached using a set screw or the like.

Although not shown in the drawings, the paper conveyance section 7, image fixing device 81, main motor unit, power supply section, etc. are also mounted on the chassis 20 of the lower housing A by positioning them using positioning pins 28 and their insertion holes.

That is, by simplifying the device to the utmost, downsizing it, and concentrating the minimum number of machine parts necessary for image formation in the main body block 30, high-precision injection molding technology can be utilized.

What is important here is that the process equipment incorporated into the main body block 30 is up to the transfer process.
When the chassis 20 and the main body block 30 are integrated, the bottom area of the synthetic resin becomes two sheets, so when the fuser 8 is loaded, if it is a thermal fuser, the synthetic resin may be deformed due to heat. If it is a telescopic or pressure fixing device, deformation and deflection due to its weight are more likely to occur. In other words, increases in material costs and molding costs, and poor accuracy due to deformation and deflection become problems.
The decision to incorporate 0 up to the transfer process has conversely reduced material costs and molding costs, and improved precision.

Thus, by assembling the image forming section, paper feeding section, and transfer section to the main body block 30 to form a unit, the drum 15
The laser irradiation position becomes accurate, especially for drum 15.
This has the effect of making the paper entry position and timing more accurate. Furthermore, since the main block 30 is three-dimensional, the structure is improved, vibrations generated from the semiconductor laser scanner and drive system are easily damped, and at the same time, resonance is less likely to occur.

In addition, by unitizing the main unit block and inspecting the unit during production, problems such as poor image formation and paper feeding can be detected in advance, allowing only approved products to be incorporated into the main unit, improving productivity. It will also happen.

C1. Effects of the Invention As described above, according to the present invention, it is possible to mutually position the image forming section and the paper feeding mechanism, as well as the fixing device, etc. with extremely high precision, so that good alignment can be achieved. In addition, the frame has high rigidity and vibrations can be reduced, so the intended purpose is well achieved.

[Brief explanation of drawings]

The drawings show one embodiment of the device; FIG. 1 is a vertical cross-sectional view of the upper case in a closed state, FIG. 2 is a view of the same as the above with the upper case opened, and FIG. Slope view, FIG. 4 is a slope view of the main body block. A is the lower casing, B is the upper casing, and 30 is the main body block.

Claims (2)

[Claims] (1) A paper feeding section that feeds transfer paper, an electrophotographic image forming section, and its light source are assembled into a main body block integrally molded from synthetic resin, and the main body block and fixing device are attached to the main body. An image recording device characterized by being positioned and attached to the chassis of the device. (2) The image recording apparatus according to claim 1, wherein the main body block to which the predetermined process means is assembled is removably attached to the main body device.