Image Forming Apparatus

Abstract

An image forming apparatus can include a body casing, a photosensitive member unit configured to be inserted into and withdrawn from the body casing, the photosensitive member unit can be moved between a first position where the photosensitive member unit is stored in the body casing and a second position where the photosensitive member unit is withdrawn from the body casing, and between the second position and a third position where the photosensitive member unit is withdrawn from the body casing. The image forming apparatus may further include a control member disposed in the body casing, the control member configured to move between a holding position in which the photosensitive member unit is prevented from moving between the second position and the third position and a release position where the photosensitive member unit is allowed to move between the second position and the third position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative aspects of the invention will be described in detail with reference to the following figures in which like elements are labeled with like numbers and in which:

FIG. 1 is a left-side sectional view of a color laser printer as an image forming apparatus according to illustrative aspects of the invention;

FIG. 2 is a left-side sectional view of a developing cartridge and a drum sub unit;

FIG. 3 is a perspective view of a drum unit viewed from an upper rear left side, wherein four developing cartridges are installed;

FIG. 4 is a perspective view of the drum unit viewed from an upper front left side, wherein one developing cartridge is being removed from the drum unit, and other developing cartridges are removed from the drum unit;

FIG. 5 is a perspective view of a developing cartridge viewed from a lower left side;

FIG. 6 is a perspective view of a body casing and the drum unit viewed from an upper front right side, wherein outer plates of the body casing and a front cover are removed and the drum unit is installed in the body casing;

FIG. 7 is a perspective view wherein rails (except for rail fixing portions and some of rail connection portions), control portions, and separation/pressing mechanisms are indicated, and control members are placed in a holding position;

FIG. 8 is a perspective view wherein the rails, the control portions, and the separation/pressing mechanisms are indicated, and the control members are placed in a release position;

FIG. 9 is a right side view showing the drum unit, the rail, the control portion, and the separation/pressing mechanism, wherein the control member is placed in the release position, and a spacer of the drum unit moves on top of the rail roller;

FIG. 10 is a right side view wherein the drum unit shown in FIG. 9 is inserted further rearward toward the body casing;

FIG. 11 is a right side view wherein the drum unit shown in FIG. 10 is inserted further rearward toward the body casing and a front roller member moves on top of the rail roller;

FIG. 12 is a right side view wherein the drum unit shown in FIG. 11 is inserted further rearward toward the body casing and the front roller member moves past the rail roller;

FIG. 13 is a right side view wherein the drum unit shown in FIG. 12 is inserted further rearward toward the body casing and an interference portion of the control member placed in the release position contacts a separation protrusion of the developing cartridge;

FIG. 14 is a right side view wherein the control member shown in FIG. 13 is placed in the holding position;

FIG. 15 is a right side view wherein the drum unit shown in FIG. 14 is inserted further rearward toward the body casing and is completely installed in the body casing;

FIG. 16 is a right side view wherein the control member shown in FIG. 15 is rotated to the release position, the drum unit is pulled frontward from the body casing, and a hook of the control member is engaged with a separation protrusion of the developing cartridge; and

FIG. 17 is a right side view wherein the drum unit shown in FIG. 14 is being pulled frontward from the body casing.

Claims

1. An image forming apparatus comprising: a body casing;a photosensitive member unit configured to be inserted into and withdrawn from the body casing, the photosensitive member unit configured to move between a first position where the photosensitive member unit is stored in the body casing, and a second position where the photosensitive member unit is withdrawn from the body casing, the photosensitive member unit configured to move between the second position and a third position where the photosensitive member unit is completely removed from the body casing, the photosensitive member unit configured to hold a plurality of photosensitive members; anda control member disposed in the body casing, the control member configured to move between a holding position in which the photosensitive member unit is prevented from moving between the first position and the third position and a release position where the photosensitive member unit is allowed to move between the second position and the third position.

2. The image forming apparatus according to claim 1, wherein when the control member is placed in the release position, the photosensitive member unit is prevented from moving between the first position and the second position.

3. The image forming apparatus according to claim 2, wherein the control member includes an interference portion configured to contact the photosensitive member unit when the control member is placed in the release position and the photosensitive member unit is moved between the first position and the second position.

4. The image forming apparatus according to claim 1, further comprising a plurality of developer supply units detachably attached to the photosensitive member unit in association with the plurality of photosensitive members, each of the developer supply units being configured to contain and supply a developer, and wherein the plurality of developer supply units are configured to be removed from and attached to the photosensitive member unit when the photosensitive member unit is placed in the second position.

5. The image forming apparatus according to claim 1, wherein the photosensitive member unit includes a rear-side gripping portion disposed at an upstream side in the withdrawal direction, and a front-side gripping portion disposed at a downstream side in the withdrawal direction, and wherein the rear-side gripping portion is operative when the photosensitive member unit is placed in the second position.

6. The image forming apparatus according to claim 1, wherein the control member includes a portion disposed on each side of the body casing in a direction perpendicular to the withdrawal direction.

7. The image forming apparatus according to claim 6, wherein the control member further comprises a connection portion configured to connect and synchronize each portion so as to cause each portion to operate simultaneously.

8. The image forming apparatus according to claim 7, wherein each portion rotates between the holding position and the release position.

9. The image forming apparatus according to claim 1, wherein the body casing includes a pair of guide walls each being formed with a guide region having a first height, the photosensitive member unit being guided in and out of the body casing through each guide region, wherein a member is disposed at a most downstream portion of each guide region in the withdrawal direction, and a second height of the guide region at the most downstream portion of the guide region is less than the first height of the guide region at an upstream portion of the guide region,wherein the control member is disposed at the most downstream portion of each guide region, the control member maintaining the second height at the most downstream portion in the holding position, the control member maintaining a third height at the most downstream portion in the release position greater than the second height,wherein the photosensitive member unit includes a guided portion at a most upstream side of the photosensitive member unit in the withdrawal direction, the guided portion being disposed in the guide region and guided along the guide region when the photosensitive member unit is inserted into and withdrawn from the body casing, anda maximum dimension of the guided portion in a direction in which the guided portion is disposed in the guide region is less than the first height and the third height, and is greater than the second height.