JPH0343660U - - Google Patents

Description

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the vicinity of the developing unit of a laser printer as an image forming apparatus implementing this invention, Fig. 2 is an overall block diagram showing the entire laser printer, and Fig. 3 is a photosensitive drum of the developing roller. Explanatory diagrams showing the press-contact state, FIGS. 4 and 5
The figures are a perspective view and a plan view for explaining a pressing mechanism that uniformly presses the developing roller against the photoreceptor drum, and FIG. 6 is a perspective view showing a mechanism that makes it possible to adjust the amount of protrusion of the engaging member from the side surface of the case. , FIG. 7 and FIG. 8 are plan views similar to FIG. 5 showing other different embodiments in which a pair of pressing members are supported at the same fulcrum, and FIG. 9 is a plan view similar to FIG. FIG. 5 is a plan view similar to FIG. 5, FIG. 7, and FIG. 8 showing an embodiment using a coil spring, and FIG. 10 is a schematic diagram illustrating the vicinity of a developing unit of a conventional image forming apparatus. 4... Photosensitive drum (latent image carrier), 7... Developing roller (developer carrier), 8... Developing unit, 18... Set screw, 20... Pressing mechanism, 21...
...Case (supporting member), 21c...Side surface, 22...
...Image forming unit case (holding member), 23... Supply roller, 24, 25... Engagement member, 26... Tension coil spring (biasing member), 27, 28, 33,
34, 36, 37, 41, 42...pressing member, 2
7a, 28a... Force point portion, 31... Guide rod, 44... Compression coil spring (biasing member), T...
Toner (developer).

Claims (1)

[Claims for Utility Model Registration] A developing unit equipped with a developer carrier carrying a developer, and an electrostatic latent image carried on the surface of which the developer is adhered by the developer carrier and a visible image. In the image forming apparatus, the developing unit is held by a holding member so as to be able to come into contact with and be separated from the latent image bearing member. A pair of engaging members whose protrusion amount with respect to the side surface can be adjusted are provided at a distance in the axial direction of the developer carrier on a side surface of a rotatably supported support member opposite to the latent image carrier, A pressing mechanism is provided on the holding member corresponding to the pair of engaging members, the pair of pressing members being interlocked by one urging member to bring the force points thereof into contact with and press the engaging members, respectively. An image forming apparatus characterized in that the developer carrier is uniformly pressed toward the latent image carrier by the pressing mechanism.