JPH0449636Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to a developing device for an optical printer.

(Prior Art) Conventionally, a developing gap has been formed by providing spacers of a predetermined thickness on both sides of a developing device that incorporates a developing sleeve as a developing means, and by bringing these spacers into elastic contact with a photoreceptor drum. I was doing it.

(Problem to be solved by the invention) However, according to this configuration, in order to bring the spacers provided on both sides of the developing device into even elastic contact with the photosensitive drum, it is necessary to adjust the photosensitive drum and the developing device with high precision. This has the disadvantage of increasing costs because it requires forming and requires extremely high mounting accuracy. Furthermore, each time the photoreceptor drum or the developing device is replaced, both must be attached with high precision, making the replacement work complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to make it possible to obtain a highly accurate developing gap extremely easily, to reduce manufacturing costs, and to facilitate replacement work of photosensitive drums and developing devices.

(Means for Solving the Problems) The main feature of the present invention is that the developing device container includes a built-in developing means that faces the photoreceptor drum with a predetermined gap, and is supported so as to be able to approach and separate from the photoreceptor drum. a biasing means for biasing the developer container toward the photosensitive drum; a pair of roller support plates swingably provided on both sides of the developer container; Gap holding rollers are provided individually and are in elastic contact with the photoreceptor drum by the urging force of the urging means, and when the developing container is separated from the photoreceptor, the gap is held via a roller support plate. and a holding means for holding the roller in a state facing the photoreceptor.

Another feature is that the holding means is a spring that is engaged between the roller support plate and the developer container.

Still another feature is that the holding means is provided in a long hole formed in one of the developer container and the roller support plate and in the other of the developer container and the roller support plate, and It consists of a regulating protrusion that protrudes into the elongated hole and regulates the range of swing of the roller support plate.

(Function) Even if there is some formation error or installation error in the photoreceptor drum or developing device, when one of the gap holding rollers comes into contact with the photoreceptor drum, the roller support plate swings and both gap holding rollers Since the photoreceptor contacts the photoreceptor drum evenly, a highly accurate developing gap is formed without being affected by these errors. In addition, during operation, the roller support plate swings following the rotation of the photoreceptor drum, and both gear holding rollers are always in equal elastic contact with the photoreceptor drum.
The developing gap is always maintained at an appropriate level without being affected by formation errors or installation errors of the photosensitive drum or the developing device.

(Example) Examples of the present invention will be described below with reference to the drawings.

As shown in the first and second figures, a developing device A is provided opposite the photosensitive drum 1. A swing shaft 3 protruding from the upper end of the developer container 2 is fitted into a groove 5 of the base plate 4, whereby the developer container 2 is supported in a swingable manner, and the photoreceptor drum 1 It is possible to approach and separate from the A roller support plate 6 is provided on both sides of the developer container 2 so as to be swingable via a central shaft 6a, and two gap holding rollers 7 that come into elastic contact with the photosensitive drum 1 are arranged on the roller support plate 6. It has been set up. A biasing spring 8 serving as biasing means is engaged between the developer container 2 and the base plate 4, and the developer container 2 is biased toward the photosensitive drum 1 and the gap is closed. The holding roller 7 is in elastic contact with the photosensitive drum 1 with a predetermined pressure. A sleeve 9 serving as a developing means is provided in the developer container 2, and the sleeve 9 faces each other with a predetermined developing gap interposed between the gap holding roller 7 and the roller support plate 6. A cam 10 is provided below the rear end of the developer container 2 and is pivotably supported on the side plate 4 . By rotating in the direction of the arrow in FIG. 1, the cam 10 presses a pressing plate 11 formed at the rear end of the developer container 2, thereby pushing the developer container 2. swings against the biasing force of the biasing spring 8, and moves away from the photosensitive drum 1 as shown in the second figure. A spring 12 serving as a holding means is engaged between the roller support plate 6 and the developer container 2, and thereby swings the developer container 2 in the direction away from the photoreceptor drum 1. Even at this time, the gap holding roller 7 is held facing the photosensitive drum 1 with the roller support plate 6 interposed therebetween.

Therefore, at the time of manufacturing, the photoreceptor drum 1
Even if there is some formation error or installation error in the developing device A, when one of the gap holding rollers 7 comes into contact with the photosensitive drum 1, the roller support plate 6 swings and both gap holding rollers 7 Since the photoreceptor drum 1 is brought into uniform elastic contact with the photoreceptor drum 1, a highly accurate development gap can be obtained without being affected by these errors. When replacing the photoreceptor drum 1, the cam 10 may be rotated to separate the developer container 2 from the photoreceptor drum 1 (as shown in the second figure). After replacing the photoreceptor drum 1, when the cam 10 is returned to its original state, the developer container 2 returns to the position facing the photoreceptor drum 1.
Both gap holding rollers 7 come into even elastic contact with the photosensitive drum 1 to form a predetermined developing gap. Further, during operation, the roller support plate 6 is attached to the photosensitive drum 1.
, and both gear holding rollers 7 are always in even elastic contact with the photoreceptor drum 1.
The developing gap is always maintained at an appropriate level without being affected by formation errors or installation errors of the photosensitive drum 1 or the developing device A. Note that both the gap holding rollers 7 are held by the roller support plate 6 and the spring 12 so as to face the photosensitive drum 1, so that when the developing device container 2 is installed or after the photosensitive drum 1 is replaced, , both gap holding rollers 7 can be brought into smooth elastic contact with the photosensitive drum 1, and the photosensitive drum 1 will not be damaged.

Note that the biasing means for biasing the developing device container 2 in the direction of the photosensitive drum 1 is not limited to the above-described biasing spring 8, and may be, for example, based on the own weight of the developing device container. Further, the means for holding the gap holding roller 7 so as to face the photosensitive drum 1 is as follows.
The structure is not limited to the spring 12 in the above-mentioned embodiment, but may be structured as shown in FIG. 3, for example. That is, a long hole 13 is formed in the roller support plate 6, and a regulating protrusion 14 is provided on the side surface of the developer container 2 so as to fit into the long hole 13, thereby regulating the swinging of the roller support plate 6. The holding means may be configured as follows. Moreover, when configured in this way, the spring 12 can be omitted, and the configuration is also simplified. In FIG. 3, solid lines and chain lines indicate a state in which the developing device A is separated from the photosensitive drum 1 and a state in which it is in elastic contact with the photosensitive drum 1, respectively.

(Effects of the invention) As described above, according to the invention, a developing gap is formed on the roller supporting plate which is swingably provided.
Since a pair of gap holding rollers are provided, even if there is a formation error or installation error in the photoreceptor drum or developing device, both gap holding rollers can be brought into even elastic contact with the photoreceptor drum by the rocking of the roller support plate. , a highly accurate development gap can be obtained.
Therefore, manufacturing becomes easier and costs are reduced. In addition, even after replacing the photoreceptor drum, there is no need to precisely install the developing device each time.
Work becomes easier. In addition, the gap holding roller is
Since the gap holding roller is held so as to face the photoreceptor drum by the holding means, it is possible to smoothly bring the gap holding roller into elastic contact with the photoreceptor drum when installing the developer container or after replacing the photoreceptor drum. and does not damage the photoreceptor drum.

[Brief explanation of drawings]

1 and 2 each relate to an embodiment of the present invention, in which FIG. 1 is a side view showing a state in which the developing device is in elastic contact with the photosensitive drum, and FIG.
The figure is a side view showing a state in which the developing device is separated from the photosensitive drum, and FIG. 3 is a side view of essential parts showing a modified example of the holding means. 1...Photosensitive drum, 2...Developer container, 6...
...Roller support plate, 7...Gap holding roller, 8
...Biasing means (biasing spring), 9...Developing means (sleeve), 12...Holding means (spring), 13...Elongated hole, 14...Regulating protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A developing device container that includes a built-in developing means that faces the photosensitive drum with a predetermined gap and is supported so as to be able to approach and separate from the photosensitive drum, and the developing device a biasing means for biasing the container toward the photosensitive drum; a pair of roller support plates swingably provided on both sides of the developer container; two roller support plates each on each of the roller support plates; a gap holding roller which is provided in elastic contact with the photoconductor drum by the biasing force of the biasing means; A developing device comprising: holding means for holding the gap holding roller in a state facing the photoreceptor through the gap holding means. (2) The developing device according to claim 1, wherein the holding means is a spring that is engaged between the roller support plate and the developing device container. (3) The holding means is provided in a long hole provided in one of the developer container and the roller support plate, and in the other of the developer container and the roller support plate, and is provided in the long hole. 2. The developing device according to claim 1, further comprising a regulating protrusion that protrudes and regulates a swinging range of the roller support plate.