JPH01219859A - Developing device - Google Patents

Abstract

PURPOSE:To facilitate adjustment of an S(sleeve)-B(blade) gap by connecting a blade member (a member regulating the thickness of a developer layer) and its supporting body through an eccentric cam (a bar member for adjusting the S-B gap). CONSTITUTION:The eccentric cam 8 consists of a right circular shaft part R and a left circular shaft part L integrally provided with shifting axis live. The right circular shaft part R is fitted in a round hole 45 provided on the blade supporting part 4A, and the left circular shaft part L is fitted into a horizontally oblong hole 46 provided on the blade part 4. As a result, the blade part 4 and its supporting part 4A are connected through the eccentric cam 8. The S-B gap located in the central area of the blade part is thereby adjustable by operating the eccentric cam 8 to rotate, and work to insert an adjustor between the blade part 4 and a developing sleeve 2 can be eliminated, thereby facilitating the adjustment of the S-B gap.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention applies to image forming apparatuses such as electrophotographic devices and electrostatic recording devices, in which latent images are formed on the surface of a latent image carrier such as an electrophotographic photoreceptor or an electrostatic recording dielectric. The present invention relates to a developing device that develops an electrostatic latent image.

More specifically, the powder developer contained in the developer container is carried as a layer on the surface of the developer carrying and conveying member, and the layer thickness of the carried developer layer is regulated by a regulating member to be conveyed to the side of the latent image holding member. The latent image is made visible, and the layer thickness regulating member is fixed to the layer thickness regulating member support member integrated with the developer container while maintaining a predetermined gap between the layer thickness regulating member and the developer carrying and conveying member. The present invention relates to a developing device equipped with the following.

(Prior Art) FIG. 9 shows a cross-sectional view of an example of the above-mentioned developing device.

1 is a developer container, and t is a developer contained in the container, which in this example is a so-called -component magnetic powder (toner).

2 is a developing sleeve as a developer carrying and conveying member.

The developing sleeve is made of a non-magnetic material such as aluminum or stainless steel, and has a shape in which approximately half the circumferential surface on the right side of the developer container L in the drawing is inserted into the container, and approximately half the circumferential surface on the left side is exposed outside the container. It is rotatably mounted on a bearing and rotated at a predetermined circumferential speed in the counterclockwise direction indicated by the arrow by a drive system (not shown).

Reference numeral 3 designates an immovable (fixed) magnet roller as a magnetic field generating member inserted and built into the developing sleeve 2, and in this embodiment, four 6fi poles 3a, 3b, 3c are arranged on the circumferential surface at a predetermined interval.・It is 3D magnetized. The developing sleeve 2 is driven to rotate approximately concentrically on the outside of the immovable magnet roller 3. Among the above magnetic poles, 3a is a developing pole, which is located on the left side of the sleeve, which is the side where the developing sleeve 2 faces the surface of the latent image holder 100, which will be described later, and 3b is a developer application rod (cut pole). , the developing sleeve 2 is located on the upper side of the sleeve, which is the side corresponding to the lower side of the blade member 4 as a developer layer thickness regulating member, which will be described later.
are developer transport poles located on the right side and lower side within the sleeve.

4 is a blade member (cut plate/doctor blade) as a developer layer thickness regulating member;
A supporting member 4A (or developer container) integral with the developer container 1 is placed above the sleeve surface with its lower side close to and facing the sleeve surface with a predetermined small gap α (hereinafter referred to as S-B gap). It is fixedly arranged on the outer surface of the front wall). This blade member 4 may be made of a magnetic material or may be made of a non-magnetic material.

Reference numeral 5 designates a crank-shaped rotating rod member that sequentially moves the developer t in the developer container 1 toward the developing sleeve 2, and is rotated clockwise as indicated by an arrow by a drive system (not shown) about a shaft 5a. Driven.

Reference numeral 100 denotes a latent image carrier such as an electrophotographic photoreceptor or an electrostatic recording dielectric, and in this example, it is drum-shaped and is driven to rotate at a predetermined circumferential speed in the clockwise direction indicated by the arrow. An electrostatic latent image is formed on the peripheral surface by the image forming process equipment, and the surface of the latent image passes through a developing section A facing the externally exposed surface of the developing sleeve 2.

E is a bias power supply that applies a developing bias between the developing sleeve 2 and the latent image holder 100.

The developer t in the developer container 1 is agitated by the rotation of the rotating rod 5; Due to the rotation of C0 and the agitation caused by the cyclical counterflow B generated by the magnetic field formed by the magnet roller 3 in the sleeve, and the contact friction with the C0 rotating developing sleeve 2 surface, the developer especially in the vicinity of the developing sleeve 2 surface is is charged with a sufficient amount of triboelectric charge with a predetermined polarity. A portion of the charged developer is sequentially held and supported magnetically and electrically as a developer layer on the circumferential surface of the rotating developing sleeve 2, and is conveyed as the sleeve rotates, passing through the lower side of the blade member 4. As a result, it is formed into a thin layer with a predetermined thickness (thin layer coating), and then goes around to the developing section A side facing the latent image carrier 100 and is used for developing the latent image on the latent image carrier 100. . The remaining supported developer layer that has not been subjected to development is carried back into the developer container 1 by the subsequent rotation of the sleeve.

The developing sleeve 2 is disposed in a non-rotating manner, and by rotating the internal magnet roller 3, a developer layer is carried and conveyed along the circumferential surface of the non-rotating developing sleeve, and is applied to the surface of the latent image holder 100. You can also do it. The developer carrying and conveying member 2 may also be an endless rotating belt member or the like.

The developing sleeve 2 as a developer carrying and conveying member improves the triboelectric charging efficiency of the developer and the developer carrying property due to the contact friction between the outer surface of the sleeve and the developer, and the amount of charge is in an optimum state overall. Appropriate surface treatment is carried out in order to always stably carry and transport a uniformly thin developer layer to the developing section A in each part and maintain high density and high image quality development efficiency.

The plate member 4 serving as a developer layer thickness regulating member is fixed to the support member 4A by screwing with screws 6. The screws are fastened at a plurality of locations along the length of the plate member at intervals as shown in FIG. 41 is the plate member 4
A vertically elongated hole 42 for inserting a screw formed in the screw fixing portion is a screw insertion hole formed on the plate member support member 4A side.

A predetermined S- at both left and right ends 0!1 of the blade member 4
The B gear α is defined by bringing the left and right ends of the lower side of the plate member 4 into contact with the cap generating plates 7 provided on both fil plate sides of the developer container 1, thereby stopping the receiver.

When the blade member 4 is made of a magnetic material, the portion of the blade member between the two ends is pulled in the direction of the developing sleeve 2 by the magnetic attraction caused by the magnetic field of the magnet roller 3 inside the developing sleeve 2, and is pulled in the direction of the two-dot chain line in FIG. It curves in an arch like water, and the S-B gear gear α becomes smaller than a predetermined value toward the longitudinal center of the blade member. If this state continues, the amount of developer applied to the longitudinal center surface of the developing sleeve 2 will be less than a predetermined amount, resulting in a decrease in density at the center of the output image.

Therefore, when assembling the blade member 4, an S-B gap adjuster (thickness gauge having a thickness corresponding to a predetermined S-B gear lug α) is inserted into the longitudinal center portion between the blade member 4 and the developing sleeve 2. After defining the S-B cap α at the longitudinal central portion of the blade member 4, the central portion of the blade member 4 is firmly fixed to the supporting member 4A by tightening the screw 6, and the S-B The cap adjustment tool is removed by pulling out the plate member 4 from between it and the developing sleeve 2.

(Problem to be solved by the invention) However, the procedure for adjusting the S-B gear gear α as described above is difficult to work with and requires a lot of effort, and the adjustment between the plate member 4 and the developing sleeve 2 is difficult. I made it in between S-B
When the gap adjuster and its removal are removed, the lower side of the plate member 4 and the developing sleeve 2 are often damaged.

Incidentally, even when a non-magnetic material is used for the plate member, a similar problem occurs because vibration appears in the central portion.

The present invention is capable of assembling the blade member 4 and the developing sleeve 2 onto the support member by accurately defining the S-B gear α over the entire longitudinal length of the blade member without the above-mentioned problems. An object of the present invention is to provide a developing device configured as follows.

(Means for Solving the Problems) The present invention allows the powder developer contained in a developer container to be supported as a layer on the surface of a developer carrying and conveying member, and the thickness of the carried developer layer is regulated by a regulating member. The layer thickness regulating member is integrated with the developer container by maintaining a predetermined gap between the layer thickness regulating member and the developer carrying and transporting member. The developer layer thickness regulating member is a developing device fixedly provided to a supporting member, and the developer layer thickness regulating member and the supporting member have partially different rotation radii at least at a substantially central portion in the longitudinal direction. The developing device is characterized in that the developing device is connected by a spacing adjustment rod-like member.

(Function) That is, when the rod-shaped member for adjusting the spacing gap (S-B gap) is rotated, the developer layer thickness regulating member (blade member) is positioned vertically with respect to the support member. Moving. Therefore, when fixing the developer layer thickness regulating member to the supporting member, by setting the rotation angle of the rod-shaped member to a predetermined value, the position of the developer layer thickness regulating member with respect to the supporting member can be controlled to a predetermined value, and the developer The gap (S-B gap) in the longitudinal center between the layer thickness regulating member and the developer carrying/conveying member (developing sleeve) is set to a predetermined value without using a gap adjuster between the two members. Can be easily adjusted and set.

Then, the developer layer thickness regulating member whose position has been adjusted is fixed to the supporting member.

In this way, the parts of the developing device are prevented from being damaged during adjustment, and the adjustment work itself is simplified, making assembly of the developing device more efficient.

(Example) Example 1 (Figs. 1 to 4) Fig. 1 (A) shows a plate member 4 as a developer layer thickness regulating member and a supporting member 4A having a rotating radius that is partially set at least in the longitudinal center portion thereof. 3 is a cross-sectional view of a portion connected by an eccentric cam 8 as a rod-shaped member for adjusting the S-B gap, which is different in terms of size, (B) is a front view of that portion, and FIG. 4, and FIGS. 3(A) and 3(B) are a side view and a front view of the eccentric cam 8.

The eccentric cam 8 consists of a circular shaft part R on the side and a left circular shaft part integrally provided with the axis of the circular shaft part R shifted, and the right circular shaft part R is on the side of the blade member support member 4A. The left circular shaft portion R is fitted into a horizontal elongated hole 46 provided on the plate member 4 side, so that the plate member 4 and the supporting member 4A are eccentrically connected. They are connected via a cam 8.

The eccentric cam 8 rotates around the right circular shaft portion R fitted into the round hole 45 of the plate member support member 4A [1. As a result of this rotation, the left circular shaft portion rotates eccentrically, and in conjunction with this rotation, the plate member 4 moves up and down with respect to the outer surface of the support member 4A.

In FIG. 1, the right circular shaft portion R is in a rotation angle state in which it is at the lowest eccentric rotation position with respect to the left circular shaft portion, and therefore the plate member 4 is at the lowest eccentric rotation position with respect to the support member 4A. It shows a state in which it is moving to a certain position. In FIG. 4, on the contrary, either the right circular shaft portion R or the left circular shaft portion is in a rotation angle state where it is located at the most -L eccentric rotation position, and therefore, relative to the plate member 4 or the support member 4A. This shows the state in which the data has been moved to the top position. The lateral elongated hole 46 on the blade member 4 side, into which the left circular shaft portion of the eccentric cam 8 is fitted and engaged, provides a margin for the eccentric cam in the lateral direction (longitudinal direction) when the eccentric cam 8 rotates. It should be wide enough horizontally.

In other words, by adjusting the rotation angle of the eccentric cam 8, the position of the plate member 4 can be adjusted from the lowest position in FIGS. 1 and 2 to the highest position in FIG. It is possible to adjust the S-B cap α between the two as appropriate.

In FIG. 2, each screw 6 for fixing the plate member
are all loosened to allow the blade member 4 to move freely in the vertical direction relative to the outer surface of the support member 4A, and then move the blade member 4 downward along the outer surface of the support member 4A to the left and right sides of the lower side of the blade member 4. The receiver is moved downward until both ends come into contact with the gap generating plates 7 provided on the respective sides and the receiver is stopped. The left and right ends of the plate member are firmly fixed to the support member 4A by sufficiently tightening the screws 6(a) and 6(a) on those sides. Next, insert the right circular shaft portion R of the eccentric cam 8 with a notch.
Alternatively, by rotating a suitable tool inserted into the developer container 1 to the left or right to adjust the angle and adjusting the vertical position of the longitudinal center portion of the plate member 4, the S-B of the longitudinal center portion of the plate member 4 can be adjusted. Adjust the gear knob α to the specified value. Then, by sufficiently tightening the screws 6(b) and 6(b) at the longitudinal center portion of the plate member with the cap α adjusted to a predetermined value, it is firmly fixed to the support member 4A. As a result, the S-B gear .alpha. is accurately defined over the entire length of the plate member 4.

After adjusting the S-B gap by adjusting the rotation angle of the eccentric cam 8, all the screws 6(a), 6(a), 6(b),
6(b) may be sufficiently tightened to fix the blade member 4 to the support member 4A.

By adopting the developing device having the above configuration, the S-B gear knob α near the center of the blade member can be adjusted by simply rotating the eccentric cam 8, and the gap between the plate member 4 and the developing sleeve 2 can be adjusted by simply rotating the eccentric cam 8. The work of inserting an adjustment tool into the gap can be omitted, making it easier to adjust the S-B gap.

Furthermore, since the S-B gap at the center of the plate member could be adjusted to A accurately, a more stable image could be obtained without causing a decrease in density at the center of the image.

Further, damage to the blade member and the developing sleeve during adjustment of the conventional S-B gap can be prevented since there is no need to insert an adjusting tool into the S-B gap.

Example 2 (Figs. 5 and 6) In this example, three identical eccentric cams 8 are used, and the plate member 4 is moved up and down at three points as shown in Fig. 5;
There is a device for adjusting the B cap α. Here, the connection structure between the plate member 4 and the support body 4A via each eccentric cam 8 and the position movement operation of the blade member are shown in Example 1-1.
This is the same as the eccentric cam 8.

In addition, in this example, the plate member 4 and the support member 4A are sandwiched between the guide rails 9 at both left and right ends thereof,
The guide rail 9 is fixed to the blade member support 4A with screws 10. FIGS. 6(A) and 6(B) show an enlarged front view and a longitudinal sectional plan view of the guide rail portion of the right full.

With the above configuration, by rotating the eccentric cam 8, the blade member 4 is moved along the guide rail 9 to the plate support 4.
It adheres to the outer surface of A and slides up and down.

That is, the S-B cap can be adjusted only by adjusting the eccentric cam, the adjustment method is simplified, and damage to the blade member and the developing sleeve can be prevented. Furthermore, since it is a three-point control, it is also possible to set the S-B gear α to an arbitrary value.

Furthermore, since the S-B gap in the longitudinal direction can be adjusted for each part, there is no variation in the S-B gap, and unevenness in the amount of developer applied in the development sleeve boot does not occur, resulting in a good image without uneven image density. Now you can get it.

Example 3 (Figures 7 and 8) This example is a developing device having an SB gap automatic adjustment mechanism.

The drive unit 20 (FIG. 7) has a small motor 21 shown in FIG. Has structure. The drive unit 20 and the sensor 23 are installed at three locations in the longitudinal direction, similar to the eccentric cam 8 of Example-2.

When the amount of developer applied on the surface of the developing sleeve 2 changes, the sensor 23 detects a change in the reflection density on the surface of the developing sleeve 2, so the amount of developer applied is changed according to the change. The sensor 23 sends a signal to the control device 24 in order to do so. Upon receiving the signal, the control device 24 drives the drive unit 20 located at the same position as the sensor 23 that transmitted the signal in accordance with the received signal.

As a result, the S-B gear α can maintain a constant amount of developer applied on the surface of the developing sleeve 2 in the longitudinal direction of the developing sleeve 2.

Therefore, it is possible to always provide an image without density unevenness such as a decrease in density at the center of the image.

It goes without saying that by using the eccentric cam 8 in this example as in Examples 1 and 2, it is effective in simplifying the assembly of the developing device and preventing damage to the blade and sleeve components.

In this example, the drive unit and the sensor are installed at three locations, but it is better to install at least three locations, or more locations than that.

(Effect of the invention) As described above, the eccentric cam (S-B gap adjustment rod-shaped member)
By adopting a developing device that connects the blade member (developer layer thickness regulating member) and the support body through the J8 adjustment of the S-B cap, adjustment can be made simply by rotating the eccentric cam. Therefore, the work of inserting an adjustment tool between the plate member and the developing sleeve can be omitted, and the S-
Adjusting the B gap has become easier. In addition, this allows accurate adjustment by eliminating variations in the S-B gap in the longitudinal direction of the plate member, eliminating unevenness in the amount of developer applied on the surface of the developing sleeve in the longitudinal direction, resulting in more stable images with no density unevenness. I was able to get it.

Furthermore, damage to the blade member and developing sleeve during adjustment of the conventional SB cap can be prevented since there is no need to insert the adjustment tool into the SB gap.

[Brief explanation of the drawing]

FIG. 1(A) is a sectional view of the eccentric cam portion connecting the blade member and the support member, FIG. 1(B) is its front view, and the second
The figure is an overall front view of the plate member attached to the plate member support member, Figures 3 (A) and (B) are side and front views of the eccentric cam, and Figure 4 is the eccentric cam that moves the blade member to the top. FIG. 5 is a front view of the plate member portion showing an example in which three eccentric cams are provided; FIG.
Figures 6 (A) and (B) are an enlarged front view and a vertical sectional view of the right guide rail portion of the plate member, and Figure 7 is the S
-B A schematic diagram of a developing device equipped with a gap automatic adjustment mechanism, FIG. 8 is a configuration diagram of the drive unit portion thereof, FIG. 9 is a cross-sectional view of an example of the developing device, and FIG. 10 is a front view of the blade member portion. It is a diagram. 2 is a developer carrying and conveying member (developing sleeve), 4 is a developer layer J7 regulating member (blade member), α is an S-B gap, and 8 is a rod member for adjusting the S-B gear (eccentric cam). Patent Applicant Canon Co., Ltd. Figure 1 (B) Figure 2 Figure 3 (2) (A) (B) Figure 4 Award 7 Figure Resistance 8 B

Claims (1)

[Claims] (1) The powder developer contained in the developer container is carried as a layer on the surface of the developer carrying and conveying member, and the layer thickness of the carried developer layer is regulated by a regulating member, and the layer is conveyed to the side of the latent image carrier. The latent image is visualized, and the layer thickness regulating member is fixed to the layer thickness regulating member support member integrated with the developer container while maintaining a predetermined gap between the layer thickness regulating member and the developer carrying and conveying member. In the developing device, the developer layer thickness regulating member and the supporting member are connected at least approximately in the central portion in the longitudinal direction by the spacing gap adjusting rod-shaped member having partially different rotation radii. A developing device characterized by: