JPH04204968A - Developing device - Google Patents

Abstract

PURPOSE:To reduce the number of parts in a developing device and to miniaturize the device by pressing a roller which presses and sets a developing unit at a specified position by the use of a specified leaf spring for energizing the roller. CONSTITUTION:The base end of the leaf spring 16 is fixed on an operation lever 9 which constitutes a part of an abutting part A, and the free end of the spring 16 is allowed to abut on and engage with a supporting shaft 12. Thus, the roller 5 of the abutting part A presses the back surface 3 of a housing 2 to lock the developing unit 1 in a stopper and hold it at the set position close to a photosensitive drum 17. By pusing the lever 9 downward in a state where the developing unit 1 is at the set position and turning a roller case 7, the abutting part A is separated from the back surface 3 and the developing unit 1 is moved to a release position. By such constitution, dimension W is made small and a member for supporting the abutting part A in the case of turning the case 7 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a developing device, and more particularly, the present invention relates to a developing device, and more particularly, to a developing device for an image forming device such as a copying machine, a facsimile machine, a page printer, etc., for holding the developing device in a set position. The present invention relates to a developing device including a contact portion that presses the back surface of a housing of a developing device.

<Prior art and problems to be solved by the invention> As a conventional developing device of this type, for example, Utility Model Application No. 63-187158
The structure disclosed in the above publication is known. This structure includes a developing device that is movable between a set position close to the photoreceptor and a released position away from the photoreceptor, and an eccentric cam as an abutting portion that abuts the rear surface of the housing of the developer. A leaf spring is interposed between the eccentric cam and the rear surface of the housing to elastically bias the developing device toward the housing. The developing unit is configured to be able to be moved to a set position or a released position by rotating the eccentric cam by a predetermined angle to press or release the free end of the leaf spring.

However, in the structure disclosed in the above publication, when the eccentric cam is rotated to press the leaf spring, it slides into contact with the eccentric cam against the spring force of the temporary spring, so a large force is required to rotate the eccentric cam. In addition, there was a problem in that the eccentric cam and the leaf spring wore out due to friction, making it impossible to obtain the proper pressing force.

Therefore, in order to solve the above problem, as shown in Figure 6,
A structure may also be considered in which a contact portion 53 that contacts the back surface 52 of the housing 51 of the developing device 50 is provided with a roller 54 that rolls into contact with the back surface 52 .

In the structure shown in FIG. 6, a support part 55 is provided to hold the contact part 53, and the support part 55 and the contact part 53 are arranged side by side so as to be relatively movable in the front and rear direction. The first support shaft 56 and the second support shaft 57 are connected to each other so as to be movable between a set position and a release position.

A contact portion 53 holds the developing device 50 in the set position.
A compression coil spring 58 that urges the back surface 52 is telescopically arranged between the first and second support shafts 56 and 57. Further, the support part 55 is supported by five third support shafts so as to be freely rotatable upward, and when the support part 55 rotates upward, the roller 54 of the contact part 53 is separated from the housing back surface 52. However, it is configured to release the bias to the developing device 51.

The structure shown in FIG. 6 employs rollers 54, so that when the support section 55 is rotated to move the developing device 5 to the set position or the release position, the rollers 54 are placed on the back side of the housing 52. On the other hand, it moves upward or downward while rolling and making contact. Therefore, it is not necessary to apply a large force to move the developing device 51 from the released position to the set position, and furthermore, it is possible to prevent the set position or the released position from being misaligned due to wear.

However, in the structure shown in FIG. 6, the support part 55 is rotated, so when the support part 55 is rotated upward, the contact part 53 or the support part 55 is supported at a predetermined rotation position. You will need some parts. Moreover, the first to third support shafts 56.5
7.59, the number of parts increases, the equipment becomes more complex, and the manufacturing cost increases.

Further, since a compression coil spring 58 that expands and contracts back and forth is disposed between the first and second support shafts 56 and 57, the dimension W in the front and back direction becomes long, and the entire device becomes large.

The present invention was made in view of the above problems, and although it employs a roller that presses the back of the housing,
The object of the present invention is to provide a developing device that has a small number of parts and can be downsized.

Means for Solving the Problems> In order to solve the above problems, the developing device of the present invention includes a developing device movable between a set position close to a photoreceptor and a released position away from the photoreceptor; a contact portion that contacts the rear surface of the housing; a support portion that supports the contact portion so as to be able to separate from the rear surface of the housing; and a spring that urges the contact portion toward the housing to hold the developer in the set position. In the developing device comprising: 1. on the abutting portion; A roller for pressing the back surface of the housing is provided, the support part and the contact part are connected to be relatively rotatable by a support shaft, and the spring part is arranged so that the free end thereof press-fits into engagement with the support shaft, and It is characterized by a plate spring fixed to either the end portion or the abutment portion or the support portion.

Effect> Due to the spring force of the leaf spring, the roller at the abutting portion urges the rear surface of the housing and holds the developing unit in the set position.

When the contact part is rotated around the spindle to move the developer, the roller rolls into contact with the back of the housing and presses the back of the housing to release the roller. When moving it to the new position, it is separated from the rear surface of the housing.

When the contact portion is rotated to move the developer to the release position, since the free end of the leaf spring is pressed into engagement with the support shaft, there is no rotation due to friction between the support shaft and the leaf spring. Dynamic resistance is generated, and due to this rotational resistance, the abutting portion and the support portion maintain the attitude in which the developing unit is moved to the release position.

<Example> Hereinafter, embodiments will be described in detail with reference to the accompanying drawings showing examples.

In a first embodiment shown in FIGS. 1 to 4, a developing device 1 includes a housing 2 forming an outer shell thereof. A rib 4 extending approximately horizontally is provided on the back surface 3 of the housing 2.
It is installed in one piece.

As shown in FIG. 1, a roller 5 is arranged on the back surface 3 below the ribs 4 so as to be able to press the back surface 3.

The roller 5 is held in a roller case 7 via a rotating shaft 6. The roller case 7 is integrally formed by bending a metal plate into a U-shaped planar shape. Both side plates 7a of the roller case 7 are formed in a modified trapezoidal shape, and a fitting hole 8 bored at the front end side of the both side plates 7a is provided with a fitting hole 8.
The rotating shaft 6 is fitted and fixed.

An operating lever 9 integrally extends upward from the upper rear end of both side plates 7a. The roller 5, roller case 7, operating lever 9, etc. constitute a contact portion A.

At the lower part of the rear end side of both side plates 7a, there is a long hole 1 extending longitudinally.
0 is bored, and a support shaft 12 is fitted into each long hole 10 so as to be rotatable and slidable back and forth. Each long hole 10
Specifically, the length in the front and rear direction is such that when the roller 5 sufficiently overcomes the lever 4 and the developing unit 1 is moved to the set position during the rotation operation of the roller case 7, which will be described later in FIGS. 3 and 4, is set so that it can press the back surface 3 and move away from the back surface 3 when moving to the release position.

Both ends of the support shaft 12 are fixed by a U-shaped support section 13 whose cross section opens forward, and this support section 13 is fixed to a main body of a copying machine as an image forming apparatus (not shown).

A pair of claw portions 14 (only one is shown in FIG. 1) are integrally provided from the front edge of the support portion 13.
comes into contact with the lower edge of the roller case 7 to restrict downward rotation of the roller case 7.

In order to urge the roller case 7 forward, the operating lever 9
The proximal end of a leaf spring 16 is fixed to the front surface of the proximal end of the leaf spring 16 by a rehet 15. The free end of the leaf spring 16 extends downward and is pressed into engagement with the support shaft 12.
The spring force of 6 is transmitted from the operating lever 9 to the roller 5 via the roller case 7, and the roller 5 is configured to press the back surface 3 of the housing 2. And these contact parts A
A combination of the support part 13 and the like are arranged in pairs on the left and right sides of the back surface 3, as shown in FIG. In FIG. 2, 17 is a photoreceptor drum, and 18 is a stopper near the rear of the photoreceptor drum 17 that restricts forward movement of the developing device 1.

According to the above structure, as shown in FIGS. 2 and 3, the base end of the leaf spring 16 is fixed to the operating lever 9 that constitutes a part of the contact part A, and the free end is attached to the support shaft 12. By press-fitting, the roller 5 of the contact portion A urges the back surface 3 of the housing 2. Therefore, the developing device 1 is locked with the stopper 18 explained in FIG.
7 is held in the set position in close proximity to the back.

In this embodiment, since the roller 5 that presses the back surface 3 of the housing 2 is used, it is not necessary to apply a large force to move the developing device 1, and furthermore, it is possible to prevent the set position or release position from being misaligned due to wear. It can also be prevented.

In addition, since the free end of the leaf spring is press-fitted to the support shaft 12 and is fixed to the operating lever 9, which constitutes a part of the proximal end or contact part A, the longitudinal dimension W of the entire device is is shortened, and the entire developing device can be made smaller.

Next, when the developing unit 1 is in the set/ret position, when the roller case 7 is rotated about the support shaft 12 by pressing down the operating lever 9, the roller 5 smoothly rolls with the back side 3. While in contact, first climb over the rib 4, then I
\ Separate from the back side 3 of Uzing 2. As a result, the developing device 1 moves to the release position shown in FIG.
move away from

In the above embodiment, the free end of the leaf spring 16 is attached to the support shaft 1.
2 and is fixed to the operating lever 9, which constitutes a part of the base end or abutting part A, so that rotational resistance due to friction is generated between the support shaft 12 and the leaf spring 16. However, due to the rotation resistance of 50 degrees, the roller case 7 and the support portion 13 are moved together by the spring force of the leaf spring 16, as shown in FIG.
Maintain the position while moving to the release position. Therefore, there is no need to provide a member to support the contact portion A when the roller case 7 is rotated, and the number of parts is reduced. Moreover, since the supporting part 13 and the abutting part A are relatively rotatably connected only by the support shaft 12 in a state where the roller 5 can be separated from the back surface 3 of the housing 2, the number of parts can be reduced. This simplifies the device and reduces manufacturing costs.

In the embodiment shown in FIG. 5, a leaf spring 16 bent in a dogleg shape
The proximal end portion of the support portion 13 is fixed to the front end surface of the support portion 13, and the free end portion of the support portion 13 is pressed into engagement with the rear side of the support shaft 12. As shown in FIG. 5, when this structure is adopted, the long hole 10 explained in FIG.
The support shaft 12 is fitted and fixed to the roller case 7.

Even when the embodiment shown in FIG. 5 is adopted, it is not necessary to apply a large force to move the developing device 1 from the release position to the set position, and furthermore, it is possible to prevent the set position or release position from shifting due to wear. can. In addition, since the plate spring 16 whose base end is fixed to the support part 13 while the free end is press-fitted to the support shaft 12 is used, the longitudinal dimension W of the entire apparatus is shortened, and the developing The entire device can be made smaller.

Furthermore, since the base end of the leaf spring 16 is fixed to the support part 13 while being press-fitted to the support shaft 12, rotational resistance due to friction between the support shaft 12 and the leaf spring 16 , the support portion 13 and the contact portion A maintain the attitude of the developing device 1 while being moved to the release position. Therefore, there is no need to provide a member to support the contact portion A when the roller case 7 is rotated, and the number of parts is reduced.

Moreover, also in the embodiment shown in FIG.
Since the two are relatively rotatably connected only by the support shaft 12, the number of parts is reduced, the device is simplified, and manufacturing costs are reduced, similar to the embodiments explained in FIGS. 1 to 4. There are advantages.

It should be noted that the above-mentioned developing device should be understood to be applicable not only to copying machines but also to all image forming devices such as facsimile machines and page printers, and various other design changes may be made within the scope of the claims. Not even.

<Effects of the Invention> As explained above, according to the present invention, a leaf spring is employed in which the free end is press-fitted to the support shaft and the base end is fixed to either the contact part or the support part. Therefore, the dimension of the entire device in the front-rear direction is shortened, and the entire developing device can be made compact.

Further, according to the present invention, the free end of the leaf spring is press-fitted to the support shaft, and the base end is fixed to either the abutment part or the support part, so that there is a gap between the support shaft and the leaf spring. Rotational resistance occurs due to friction, and this rotational resistance causes the support part and the contact part to
Keep the developing unit in the released position.

Therefore, there is no need to provide a member to support the abutting part when the abutting part is rotated, and the number of parts is reduced.

In addition, the rollers that make up the contact part can be separated from the back of the housing, and the support part and the contact part are connected to each other so that they can rotate relative to each other only by the support shaft, which also reduces the number of parts ( This simplifies the equipment and reduces manufacturing costs.

Furthermore, since a roller is used to press the rear surface of the housing, it is not necessary to apply a large force to move the developing device from the release position to the set position, and it is also possible to prevent misalignment due to wear.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing essential parts of an embodiment of the present invention, FIG. 2 is a schematic plan view showing a developing device set state of the embodiment of FIG. 1, and FIG. 3 is a developing device of the embodiment of FIG. 1. FIG. 4 is a schematic side view showing the developing device in the released state of the embodiment shown in FIG. 1; FIG. 5 is a perspective view showing the main parts of another embodiment; FIG. FIG. ]・Developing device, 2...＼＼jink, 3...＼＼back side, 5... roller, 13... support part, 16... leaf spring (spring part), A contact part.

Claims (1)

[Claims] 1. A developing device that is movable between a set position close to the photoreceptor and a released position that is away from the photoreceptor, a contact portion that contacts the rear surface of the housing of the developer device, and a contact portion that can be separated from the rear surface of the housing. and a spring portion that urges the abutting portion toward the housing to hold the developing device in the set position, the developing device includes a spring portion that urges the abutting portion toward the housing, the back surface of the housing being pressed against the abutting portion. A roller is provided, the support part and the contact part are connected to be relatively rotatable by a support shaft, and the free end of the spring part is pressed into engagement with the support shaft, and the base end is connected to the contact part. 1. A developing device comprising a leaf spring fixed to either one of a part and a supporting part.