Image forming device including transfer tape

Abstract

An image forming apparatus comprises image forming stations Y, M, C, K for respective colors arranged along a transfer belt 16, each image forming station including an image carrier 20, a charging means 22 and a developing means 24 disposed around the image carrier 20. The apparatus further comprises a housing body 2 in which said image forming stations and said transfer belt are situated, a support frame 9a for supporting roller 14 around which said transfer belt is laid with some tension, and an image density detecting means 18 which is arranged to face said transfer belt, wherein said support frame is attached to the housing body such that the support frame is detachable relative to the housing body by means of pivotal movement. The apparatus has a locking means 9c for locking said support frame to the housing body, wherein said image density detecting means is disposed in proximity to said locking means, thereby preventing the deterioration of the detecting accuracy of the image density detecting means.

Description

technical field [0001] The present invention relates to a tandem image forming apparatus in which image forming stations equipped with charging members and developing members are arranged for each color along a transfer belt around an image carrier, and a color image is formed by passing the transfer belt through each station. Background technique [0002] As the above-mentioned tandem image forming apparatus, the following technology is disclosed in, for example, Japanese Patent Laid-Open No. 11-95520: a transfer belt (sheet belt) is stretched obliquely with a plurality of rollers, Parts of multiple laser scanning units are stacked on a plurality of image forming stations arranged in the stretching direction of the belt to miniaturize the entire device, and the space obliquely below the stretched transfer belt is used as a space for double-sided printing. The paper turning path, or a space for handling when the paper feed cassette is installed or when the recording medium i...

AI Technical Summary

Problems solved by technology

[0004] However, in the above-mentioned conventional methods, although the entire image forming apparatus is miniaturized by arranging the transfer belt obliquely or using an array-shaped writing head, the method for operating the image forming apparatus is used to further realize the miniaturization of the apparatus. The layout of the circuit becomes an important issue

[0005] In particular, in the tandem image forming apparatuses of each of the above-mentioned conventional methods, there is a problem that, in order to simultaneously operate a plurality of image forming stations, high-voltage power supply substrates such as a charging member, a developing member, and a transfer member, etc. The power supply board for performing mechanical operations during the forming process and the interface board for separating image data sent from a host computer etc. above or below, the result is that the device cannot be miniaturized

In the method of the above-mentioned (Japanese Patent) Unexamined Patent Publication No. Hei 11-95520, when the recording medium is jammed, it is necessary to remove the recording medium after each image forming station is pulled out along the axial direction of the image carrier to remove the jamming. The recording medium is very troublesome, and it may damage the surface of the image carrier or transfer belt when it is removed, resulting in image defects

In addition, the recording medium can also be removed after the transfer belt is rotated and withdrawn, but a space for rotating and withdrawing the transfer belt is required, and the size of the device cannot be realized.

Furthermore, it is necessary to provide openings for inserting and extracting each image forming station or removing a jammed recording medium along the axial direction of the image carrier on the frame for correctly positioning the various parts of the supporting device, which may reduce the rigidity of the frame. image quality deterioration

[0007] In addition, in the above-mentioned method of (Japanese Patent) Laid-Open No. 2001-249522, there is the following problem: because the openings for replacing the image forming stations and the openings for removing jammed recording media are provided in different directions, It is unclear which opening the operator should operate for maintenance

In addition, there is a problem that since the transfer belt is detached from the main body of the image forming apparatus when replacing each image forming station, the operator needs to reserve a space for temporarily placing the transfer belt around the image forming apparatus when replacing the image forming station, Therefore, it is troublesome to replace, and it will damage the transfer belt when it is temporarily placed

[0010] However, the image forming apparatus proposed above has the following problem: Since the transfer belt is detached from the casing main body every time of maintenance, the image density detection member does not move when the transfer belt is rotated to return to its original position. The position will shift, and as a result, the distance between the image density detection member and the transfer belt will fluctuate, and the detection accuracy will decrease

[0011] The present invention is to solve the above-mentioned conventional problems and problems, and its object is to prevent the detection accuracy of the image density detection means from deteriorating in an image forming apparatus in which a transfer belt can be rotatably attached to and detached from a casing main body.

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