JPH0239253U

JPH0239253U -

Info

Publication number: JPH0239253U
Application number: JP11681088U
Authority: JP
Priority date: 1988-09-07
Filing date: 1988-09-07
Publication date: 1990-03-15
Anticipated expiration: 2003-09-07
Also published as: JPH0720675Y2

Description

[Brief explanation of the drawing]

第１図は本考案の第１実施例の感光体、現像ロ
ーラ及びバツクアツプローラの配置を示す正面図
、第２図は本考案の第２実施例についての同様の
図、第３図は先に提案された本考案が適用される
多色画像形成装置の感光体の周りの機器の配置を
示す正面図、第４図はその装置に使用される１成
分接触現像装置の１例の構成を示す断面図、第５
図及び第６図はその装置の現像ニツプ幅を説明す
る説明図である。１……感光体ベルト、２，３……感光体ベルト
支持ローラ、６，８，１０，１２，４１……現像
ローラ、７，９，１１，１３……現像装置、５０
，５０′，５０″……バツクアツプローラ（バツ
クアツプ部材）。 FIG. 1 is a front view showing the arrangement of the photoreceptor, developing roller and back-up roller of the first embodiment of the present invention, FIG. 2 is a similar view of the second embodiment of the present invention, and FIG. FIG. 4 is a front view showing the arrangement of equipment around the photoreceptor of a multicolor image forming apparatus to which the present invention proposed in 1999 is applied. FIG. Cross-sectional view shown, No. 5
FIG. 6 is an explanatory diagram illustrating the width of the developing nip of the apparatus. 1... Photoreceptor belt, 2, 3... Photoreceptor belt support roller, 6, 8, 10, 12, 41... Developing roller, 7, 9, 11, 13... Developing device, 50
, 50', 50''...backup roller (backup member).

Claims

[Claims for Utility Model Registration] (1) An endless belt-like flexible photoreceptor stretched over a plurality of support rollers, and a photoreceptor between two adjacent support rollers among the plurality of support rollers. It has a plurality of developing devices which are sequentially provided along the road and have developers of different colors, and a plurality of toner images developed by these developing devices and sequentially formed on a photoreceptor are transferred onto a single sheet of transfer paper. The multicolor image forming apparatus performs overlapping transfer, and each of the above-mentioned developing devices has a developing roller that can come into contact with and separate from the outer peripheral surface of the photoreceptor by moving it in a direction perpendicular to the surface of the photoreceptor. The developing roller of the developing device is normally spaced apart from the photoreceptor and is pressed against the outer peripheral surface of the photoreceptor during development in the developing device to perform contact development. The distance between the points of contact with the photoconductor is equal, and the distance between the contact point of the developing roller at both ends with the photoconductor and the end of the contact portion of the photoconductor with the support roller is equal to the distance between the contact points of the developing roller mentioned above. A back-up member is provided in contact with the inner circumferential surface of the photoreceptor at a normal position at each center position between the contact points of adjacent developing rollers to the photoreceptor, and is arranged so as to be 1/2 the distance between the two. Features of multicolor image forming device. (2) In the multicolor image forming apparatus according to claim 1, the number of developing rollers is four, and the backup member is located at a central position between the contact points of the two central developing rollers to the photoreceptor. A multicolor image forming apparatus characterized in that only one image forming apparatus is provided. (3) The multicolor image forming apparatus according to claim 1 or 2, wherein the developer is a one-component developer.