Belt cartridge for a printing apparatus

Abstract: A belt cartridge for use in a printing apparatus including a base board (110) attachable to or detachable from a belt unit to be capable of facing the belt unit at one surface, a support unit (140) movably installed on the base board to be capable of selectively contacting the inner surface of the photoreceptor belt, and a moving means (142) for approaching the support unit to or isolating the same from the base board. The belt cartridge carries the photoreceptor belt (40) for easy installation onto and removal from the rollers (31,32,33,34) of the belt unit of the printing apparatus.

Description: The present invention relates in general to a belt cartridge for use in a printing apparatus, and more particularly to a belt cartridge for mounting a photoreceptor belt on a belt unit in a printer and for use in withdrawing a worn-out photoreceptor belt. Figure 1 shows a printing apparatus such as a printer or a photocopier including a photoreceptor belt 10 and a developing unit 20. The photoreceptor belt 10 is supported by a plurality of rollers 11, 12 and 13 installed within the main body of the printing apparatus and circulates along an endless track. The developing unit 20 develops electrostatic latent images formed on the surface of the photoreceptor belt 10. The photoreceptor belt 10 ages with long use, so the aged photoreceptor belt should be replaced with a new photoreceptor belt to maintain the precision of an image. In a conventional method of replacing the photoreceptor belt 10, a movably installed roller 13 among the plurality of rollers 11, 12 and 13 is moved to a position shown by the dotted line to release tension of the photoreceptor belt 10, the photoreceptor belt 10 is extracted from the printing apparatus, a new photoreceptor belt is inserted directly by hand, and the roller 13 is then moved back to the original position and tension is again applied to the new photoreceptor belt. The photoreceptor belt 10 is flexible, so replacement thereof is very complicated and difficult. Besides, the photoreceptor belt 10 may be mismounted in the printing apparatus by an inexperienced operator. JP 04147274 discloses a process cartridge for an image forming device having a pair of rotational shafts for removing a photosensitive belt. US-A-4 416 532 discloses another photoreceptor belt cartridge, in which a shoe is contactable to the belt by means of a lever. It is an aim of the present invention to provide an apparatus to aid mounting of a new photoreceptor belt on a belt unit and ideally to aid removal of a used photoreceptor belt from the belt unit. According to the present invention there is provided a belt cartridge as set forth in the claims appended hereto. Preferred features of the present invention will be apparent from the dependent claims and the description which follows. According to a first aspect of the present invention there is provided a belt cartridge for use in a printing apparatus having a belt unit for receiving a photoreceptor belt, the belt cartridge comprising: a base board detachably couplable to the belt unit; a support unit for selectively contacting an inner surface of the photoreceptor belt; and moving means for moving the support unit with respect to the base board such that the support unit selectively either contacts or does not contact the inner surface of the photoreceptor belt. Preferably, the base board is arranged to be capable of facing the belt unit at one surface; and the support unit is arranged to be movably installed on the base board. Preferably, the support unit is expandable to an expanded state contacting the inner surface of the photoreceptor belt, and collapsible to a collapsed state remote from the inner surface of the photoreceptor belt. Preferably, the support unit comprises: a first support unit having a plurality of first support bars moveable in response to the moving means to expand or collapse along a path generally perpendicular to the inner surface of the photoreceptor belt; and a second support unit having a plurality of second support bars moveable in response to the moving means along a path generally perpendicular to the path of the first support bars and generally perpendicular to a second portion of the interior surface of the photoreceptor belt. Here, it is preferable that the support unit includes: a first support unit selectively contacting the inner surface of the photoreceptor belt while approaching each other or being separated from each other upward and downward having the base board therebetween; and a second support unit selectively contacting the inner surface of the photoreceptor belt while approaching each other or being separated from each other from side to side having the base board therebetween. Also, preferably, the first support unit includes: a plurality of first support bars which selectively contact the inner surface of the photoreceptor belt and are spaced a predetermined distance apart from each other to avoid interference with the belt unit; and first brackets which support one end of each of the first support bars and are movably installed on the base board. It is preferable that the second support unit includes; a plurality of second support bars which selectively contact the inner surface of the photoreceptor belt and are spaced a predetermined distance apart from each other to avoid interference with the belt unit; and second brackets which support one end of each of the second support bars and are slidably installed on the base board. Preferably, the moving means includes: a cam rotatably installed on the base board to be capable of contacting the first support unit; connection members each hinged on the second support unit and the cam; and elastic members for elastically biasing the first support unit toward the cam. For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 is a schematic configuration view of a general printing apparatus; Figure 2 is a schematic perspective view of a belt cartridge in a printing apparatus according to a preferred embodiment of the present invention; and Figures 3 and 4 are schematic front views illustrating the operation of the belt cartridge of Figure 2. Referring to Figure 2, a belt cartridge in a printing apparatus according to a preferred embodiment of the present invention includes a base board 110, a support unit 140, and a moving means. The base board 110 can be attached to and detached from a belt unit to be capable of facing the belt unit having a plurality of support rollers 31, 32 and 33 and backup rollers 34 carried on a frame 30. The support unit 140 is movably installed on the base board 110 to be capable of selectively contacting the inner surface of the photoreceptor belt 40. The moving means moves the support unit 140 toward and separates it from the base board 110. The support unit 140 can be expanded to contact the inner surface of the photoreceptor belt. In this expanded configuration the photoreceptor belt 40 is carried on the support unit 140. Alternatively, the support unit 140 is moveable to a collapsed configuration to lie remote from the surface of the photoreceptor belt 40. In the collapsed configuration the photoreceptor belt is carried on the belt unit including the support rollers 31, 32 and 33 and backup rollers 34, such as during a normal printing operation. In the preferred embodiment the support unit 140 in the collapsed configuration does not impede the normal operation of the belt unit. The support unit 140 includes a pair of first support units 120 installed to be capable of approaching each other and isolating them from each other (i.e. generally toward or away from each other) in a generally upward and downward orientation, having the base board 110 therebetween, and a pair of second support units 130 capable of approaching each other and isolating them from each other (i.e. moving generally toward or away from each other) from side to side, again having the base board 110 therebetween. Each of the first support units 120 is supported by a first bracket 124 movably coupled to the base board 110, and has a plurality of first support bars 122 which selectively contact the inner surface of the photoreceptor belt 40. The first support bars 122 are spaced a predetermined distance apart from each other to avoid interference with the support rollers 31, 32 and 33 and the backup rollers 34. It is preferable that the first support bars 122 each have a plate spring structure which is round toward the inner surface of the photoreceptor belt 40 to prevent warping due to the load of the photoreceptor belt 40. The first bracket 124 is warped longitudinally in consideration of the arrangement positions of the first support bars 122. A plurality of guide members 126 are located on the first bracket 124 slidably coupled to first guide portions 112 installed on the base board 110. Each of the second support units 130 is supported at one end by each second bracket 134 slidably installed on the base board 110, and has a plurality of second support bars 132 that selectively contact the inner surface of the photoreceptor belt 40. The second support bars 132 are spaced a predetermined distance apart from each other to avoid interference with the support rollers 31 and 33. It is preferable that the second support bars 132 each have a plate spring structure which is round toward the inner surface of the photoreceptor belt 40 to prevent warping due to the load of the photoreceptor belt 40, similar to the first support bars 122. One end of the second bracket 134 is slidably coupled to a second guide portion 114 installed on the base plate 110, and the other end thereof is branched at a predetermined position to support the second support bars 132 spaced a predetermined distance from each other. The moving means includes a cam 142 rotatably installed on the base board 110 to be capable of contacting the first brackets 124, connection members 144 each hinged on the second bracket 134 of each of the second support unit 130 and on the cam 142, and elastic members 146 for elastically biasing the first brackets 124 toward the cam 142. The cam 142 is installed so that its outer circumferential surface comes into contact with the substantial centers of the first brackets 124, and a cam shaft 141 is rotatably coupled to the base board 110 and the frame 30. It is preferable that the elastic members 146 are tensile springs each connected to each of the first bracket 124 and the base board 110 In the operation of the belt cartridge for a printing apparatus according to the preferred embodiment of the present invention having such a configuration, as shown in Figure 3, the belt cartridge supporting the photoreceptor belt 40 is inserted into the belt unit in an expanded state where the plurality of first support bars 122 and second support bars 132 are separated a maximum distance from the cam 142 since the large diameter portion of the cam 142 contacts the first brackets 124. Then, the photoreceptor belt 40 is located to be capable of covering the outer surfaces of the plurality of support rollers 31, 32, 33 and backup rollers 34. Here, the support roller 33 is in a state of approaching the cam 142. Next, one end of the cam shaft 141 is coupled to the frame 30 to fix the position of the belt cartridge with respect to the frame 30 and the belt unit. Thereafter, as shown in Figure 4, when the cam 142 is rotated about 90° by a predetermined driving source (not shown), the first brackets 124 biased by the elastic members 146 are moved toward the cam 142, and the second brackets 134 are moved toward the cam 142 by the connection members 144 which interlock with the cam 142. That is, the interval between the first and second brackets 124 and 134 is at a minimum and the belt cartridge is in a collapsed state. In this way, the first and second support bars 122 and 132 are detached from the photoreceptor belt 40, and simultaneously, the photoreceptor belt 40 comes into contact with the support rollers 31, 32 and 33 and the backup rollers 34 and is supported by them. At this time, when the support roller 33 is moved away from the cam 142 starting from a position indicated by a dotted line, tension with which normal printing can be performed is applied to the photoreceptor belt 40. Meanwhile, the belt cartridge mounted on the belt unit does not interfere with the movement of the support rollers 31, 32 and 33 and the backup rollers 34, so that it can be continuously mounted on the belt unit. In order to replace a contaminated photoreceptor belt 40 or repair the belt cartridge, the support roller 33 is moved to the position indicated by the dotted line, and the cam 142 is rotated 90°, so that the first and second brackets 124 and 134 of the belt cartridge are separated a maximum distance from the cam 142 as shown in Figure 3. Then, the photoreceptor belt 40 is separated from the support rollers 31, 32 and 33 and again contacts the first and second support bars 122 and 132 and is supported by them. At this time, the belt cartridge is separated from the belt unit, so that the photoreceptor belt 40 is also removed. In the belt cartridge as described above, the support bars installed on the first and second brackets interlocking with the cam selectively contact the photoreceptor belt, such that printing is performed in the printing apparatus in which the belt cartridge is continuously installed without being separated from the belt unit even after the photoreceptor belt 40 is mounted on the belt unit. Therefore, the photoreceptor belt can be easily replaced, and mismounting of the photoreceptor belt can be prevented by avoiding the conventional manual belt replacing operation.

Claims: A belt cartridge for use in a printing apparatus having a belt unit (31-34) for receiving a photoreceptor belt, the belt cartridge comprising: a base board (110) detachably couplable to the belt unit; a support unit (140) for selectively contacting an inner surface of the photoreceptor belt; and moving means (142) for moving the support unit (140) with respect to the base board (110) such that the support unit selectively either contacts or does not contact the inner surface of the photoreceptor belt. The belt cartridge as claimed in claim 1, wherein: the base board (110) is arranged to be capable of facing the belt unit at one surface; and the support unit (140) is arranged to be movably installed on the base board. The belt cartridge as claimed in claim 1 or 2, wherein the support unit (140) is expandable to an expanded state contacting the inner surface of the photoreceptor belt, and collapsible to a collapsed state remote from the inner surface of the photoreceptor belt. The belt cartridge as claimed in claim 3, wherein the support unit (140) comprises: a first support unit (120) having a plurality of first support bars (122) moveable in response to the moving means to expand or collapse along a path generally perpendicular to the inner surface of the photoreceptor belt; and a second support unit (130) having a plurality of second support bars (132) moveable in response to the moving means along a path generally perpendicular to the path of the first support bars and generally perpendicular to a second portion of the interior surface of the photoreceptor belt. The belt cartridge of any of claims 1 to 4, wherein the support unit (140) comprises: a first support unit (120) for selectively contacting the inner surface of the photoreceptor belt (44) while approaching each other or being separated from each other upward and downward having the base board (110) therebetween; and a second support unit (130) for selectively contacting the inner surface of the photoreceptor belt while approaching each other or being separated from each other from side to side having the base board (110) therebetween. The belt cartridge of claim 5, wherein the first support unit (120) comprises: a plurality of first support bars (122) arranged in use to selectively contact the inner surface of the photoreceptor belt (40) and which are spaced a predetermined distance apart from each other to avoid interference with the belt unit (30); and first brackets (124) which support one end of each of the first support bars and are movably installed on the base board (110). The belt cartridge of claim 5 or 6, wherein the second support unit (130) comprises: a plurality of second support bars (132) arranged in use to selectively contact the inner surface of the photoreceptor belt (40) and which are spaced a predetermined distance apart from each other to avoid interference with the belt unit (30); and second brackets (134) which support one end of each of the second support bars and are slidably installed on the base board. The belt cartridge of any of claims 1 to 7, wherein the moving means comprises: a cam (142) rotatably located on the base board (110) to be capable of contacting the first support unit (120); connection members (144) each hinged on the second support unit (130) and the cam (142); and elastic members (146) for elastically biasing the first support unit (120) toward the cam (142).

Inventors: PANG JEONG-HUN, PANG, JEONG-HUN
Applicants: SAMSUNG ELECTRONICS CO LTD, SAMSUNG ELECTRONICS CO. LTD.
Application year: 1999
Main classification: G03G15
IPC codes: G03G21, G03G15, B41J2