JPH0626913Y2 - Gap adjustment structure of developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding a gap adjusting structure of a developing device that keeps a constant gap between a photosensitive drum and a developing roller that constitutes an electrophotographic printer, it is necessary to facilitate adjustment and improve workability. For the purpose, in a developing device which is arranged corresponding to the photosensitive drum and performs development while maintaining a constant gap with the photosensitive drum, the developing device is held by three legs that are vertically moved and finely adjusted. ,
A first adjusting leg and a second adjusting leg which are located at a rear part of the developing device on a straight line parallel to the photosensitive drum and are finely adjusted by rotating a foot, and a center of a front part of the developing device near the photosensitive drum. Located in
It comprises a third adjusting leg which is finely adjusted by rotating a knob of an operation tool provided on a side portion of the developing device.

[Industrial application field]

The present invention relates to a gap adjusting structure of a developing device that keeps a constant gap between a photosensitive drum and a developing roller that constitute an electrophotographic printer.

For example, in the electrophotographic printer shown in FIG. 3, a charging device 2, a developing device 3, a transferring device 4, a discharging device 5, and a cleaner 6 are provided around a photosensitive drum 1 having a photosensitive layer on its surface.
Is arranged, the photoconductor drum 1 rotates counterclockwise and is uniformly charged by the charger 2, and then the photoconductor drum 1 is exposed by the electrostatic latent image corresponding to the optical image on the photoconductor drum 1. An image is formed and developed into a visible image by the developing device 3. On the other hand, the paper PP taken out from the paper cassette (not shown)
Waits on the waiting roller 7, and the waiting roller 7 guides the transfer device 4 in synchronization with the rotation of the photosensitive drum 1.
The image on the photosensitive drum body 1 is transferred to a sheet by a transfer device, and the transferred sheet is sent from the photosensitive drum to a fixing device 8 and is stored in a stacker (not shown) after fixing. It On the other hand, after the photoconductor drum 1 is transferred to the paper, the charge is removed by the charge eliminator 5, cleaned by the cleaner 6, and the process starting from the charger 2 is repeated.

The developing device 3 used in such an electrophotographic printer includes a toner supply cartridge, a toner supply roller, a stirring roller,
A developer that consists of a developing roller and a blade, and the stirring roller rotates to mix toner and carrier (iron powder).
Transmit TCA to the developing roller while stirring. The developing roller has a magnet inside, attracts the carrier of the developer TCA that has been transmitted, forms a magnetic brush of the developer TCA on its surface, and rotates clockwise to convey the developer TCA, The height of the magnetic brush-shaped developer TCA is made constant by the blade (the height of the brush is regulated), and then the photoconductor drum 1 and the developer TCA are brought into contact with each other to form a toner on the electrostatic latent image on the photoconductor drum 1. Is attracted by suction and development is performed.

[Conventional technology]

As described above, in the electrophotographic printer, the developer TCA is brought into contact with the photosensitive drum 1 from the developing roller (also referred to as a magnet roller) forming the developing device 3, and
Since the toner is sucked and attached to the upper part, it is extremely important to adjust the gap between the photoconductor drum 1 and the developing device 3. Therefore, conventionally, the developing device 3 can be moved up and down and finely adjusted. It was held on four legs.

FIG. 4 shows a perspective view of an essential part for explaining the conventional adjusting structure. In order to adjust the gap G between the photosensitive drum 1 and the developing device 3, the developing device 3 arranged in parallel with the photosensitive drum 1 is shown. Attach two L-shaped plates 11 with female threads on both sides,
The adjustment leg 12 having a male screw was fitted to it, and the four feet 2F were each rotated and finely adjusted to adjust the gap. For example, when the gap G between the photoconductor drum and the developing device is set to 2 mm, the gap variation error must be about ± 5/100 mm.

[Problems to be solved by the device]

However, it takes time to make fine adjustments by individually rotating the four feet 2F, and in addition,
It is very difficult to adjust the two feet 2F on the back side because they are in a recessed position. That is, in FIG. 4, the adjustment leg 12 is shown by a solid line on the front side F, and the adjustment leg 12 is shown by a broken line on the back side B, and the openable side lid of the electrophotographic printer is shown. It refers to the position from.

Accordingly, the present invention proposes a gap adjusting structure of a developing device for eliminating such difficulty of adjustment, facilitating the adjustment and improving workability.

[Means for Solving the Problems]

The problem is, as in the embodiment shown in FIG. 1, in the developing device 3 which is arranged corresponding to the photoconductor drum 1 and performs development while maintaining a constant gap with the photoconductor drum. Reference numeral 3 denotes a first adjusting leg 21 which is held by three legs which move vertically and are finely adjusted, and which is located at a rear portion of the developing device on a straight line parallel to the photosensitive drum 1 and rotates a foot 2F for fine adjustment. And the second adjusting leg 22, and an operation tool provided at the side of the developing device, which is located at the center of the front part of the developing device close to the photosensitive drum.
This is solved by the gap adjusting structure of the developing device which is composed of the third adjusting leg 23 which is finely adjusted by rotating the knob 32 of 31.

[Action]

That is, according to the present invention, the first adjusting leg (the adjusting leg on the rear side) provided in the rear portion in parallel with the photosensitive drum is pre-adjusted so that it is not necessary to adjust the adjusting leg on the rear side, which is very difficult to adjust. To the reference position, then finely adjust the second adjusting leg on the front side to arrange the developing device parallel to the photosensitive drum, and then extend the third adjusting leg located at the center of the developing device to the side. Finely adjust with the knob of the existing operation tool. The gap is adjusted to a predetermined value by operating the third adjusting leg.

Then, the gap adjustment becomes easy and the workability is improved.

〔Example〕

Referring to the drawings, a detailed description will be given of an embodiment with reference to the drawings. FIG. 1 is a perspective view of an essential part for explaining an adjusting structure according to the present invention. Reference numeral 1 is a photosensitive drum, 3 is a developing device, 21 is a first adjusting leg, 22 is a second adjusting leg, 23 is a third adjusting leg, 31 is an operating tool, and 32 is a knob. Also, 11 is an L-shaped plate, 2F is a foot, these are the first
It is attached to the adjusting leg 21 and the second adjusting leg 22. Furthermore, FIG. 2 shows a perspective view of the third adjusting leg 23. In FIG. 2, reference numeral 31 is an operating tool, 32 is a knob, 33 is a worm gear, 34 is a worm wheel, 35 is a fixed foot, and 36 is a fixed foot. It is screw stick. For operation of the third adjusting leg 23, when the knob 32 is manually turned, the operation tool 31 rotates and the worm gear on the same axis is rotated.
33 rotates, the worm wheel 34 turns, and the fixed foot
The worm wheel 34 moves up and down with respect to the screw stick 36 fixed to 35. Since the worm wheel 34 is attached to the developing device case, the third adjusting leg 23 is finely adjusted up and down. The screw stick 36 is attached in a state of protruding from the developing device case to the inside of the developing device.

Next, the entire gap adjusting method will be described. First, the first adjusting leg 21 on the back side B is adjusted in advance to the reference position as designed, and then the second adjusting leg 22 on the front side F is footed. 2F is moved to perform fine adjustment, and the first adjusting leg 21 and the second adjusting leg 22 arrange the lengthwise direction of the developing device parallel to the cylindrical direction of the photosensitive drum. Then, as described above, the third adjusting leg 23 located at the center of the developing device is finely adjusted by the knob of the operation tool that extends laterally. This third adjusting leg 23
Is located near the center of gravity of the developing device 3 and is operated to adjust the gap G. At that time, the gap between the photoconductor drum and the developing unit may be adjusted to a constant linear width, and therefore the gap adjustment can be sufficiently performed by the adjusting method according to the present invention.

With this configuration, if the first adjusting leg 21 is adjusted in advance, the gap can be adjusted by only manually operating the foot of the second adjusting leg 22 on the front side F and the knob 32 of the third adjusting leg 23. In addition, the rear height of the developing device need not be finely adjusted, and the first adjusting leg 21 and the second adjusting leg 22 only need to dispose the developing device and the photosensitive drum in parallel. 1 The readjustment of the adjusting leg 21 is almost unnecessary, and the workability thereof is greatly improved.

[Effect of device]

As is clear from the above description, according to the adjusting structure of the present invention, the hook of the second adjusting leg and the knob of the third adjusting leg are provided.
The gap can be easily finely adjusted only by manually operating 32, and the workability can be significantly improved.

[Brief description of drawings]

 FIG. 1 is a perspective view illustrating an adjusting structure according to the present invention, FIG. 2 is a perspective view of a third adjusting leg, FIG. 3 is a view illustrating an electrophotographic printer, and FIG. 4 is a conventional adjusting structure. It is a perspective view explaining. In the figure, F is the front side, B is the back side, 1 is a photosensitive drum, 3 is a developing device, 11 is an L-shaped plate, 2F is a foot, 12 is an adjusting leg, 21 is a first adjusting leg, and 22 is a second. The adjusting leg, 23 is the third adjusting leg, 31 is an operating tool, 32 is a knob, 33 is a worm gear, 34 is a worm wheel, 35 is a fixed foot, and 36 is a screw stick.

Claims (1)

[Scope of utility model registration request] 1. A developing device (3) arranged corresponding to a photoconductor drum (1) for performing development while maintaining a constant gap with the photoconductor drum. The first adjusting leg (21) which is held by three legs that are moved and finely adjusted, is located at the rear of the developing device on a straight line parallel to the photosensitive drum (1), and is finely adjusted by rotating the foot (2F). ) And the second adjusting leg (22), and located in the center of the front part of the developing device near the photoconductor drum,
The gap adjustment of the developing device, which comprises a third adjusting leg (23) which is finely adjusted by rotating a knob (32) of an operation tool (31) provided on a side portion of the developing device. Construction.