Mita Industrial Co., Ltd.

Tetsuya Ichigotani

Masahiko Miyazaki

Naoyuki Ishida

Takahisa Nakaue

Yoshifumi Okauchi

Yukihiro Ito

Shoji Hirano

Tadahiro Kiyosumi

Junichi Inada

Hiroshi Wada

Susumu Hanano

Takeshi Sakaguchi

Susumu Takehara

Eijiro Masaki

Sinji Yamamoto

An image-forming machine has a sheet member conveying passage extending through a transfer zone and a fixing zone, a sheet member-feeder for feeding a sheet member to the sheet member conveying passage, and a sheet member conveyor for conveying the sheet member through the sheet member conveying passage. A housing of the image-forming machine has a lower surface defined by an intermediate lower wall and an upper surface defined by an intermediate upper wall, and has a space of which the front surface is opened. The downstream end portion of the sheet member conveying passage extends along one side portion of the intermediate lower wall on the lower side thereof. That one side portion of the intermediate lower wall is defined by an opening/closing member which is brought to the open position to open the downstream end portion of the sheet member conveying passage. The sheet member conveyer includes a pair of register rollers. After the leading edge of the sheet member delivered to the sheet member conveying passage is brought into contact with the nip of the pair of register rollers, the pair of register rollers are preliminarily rotated for only a predetermined period of time.

Image-forming machine capable of opening to permit ready access to

An image-forming machine comprises a sheet member conveying passage extending through a transfer zone and a fixing zone, a sheet member-feeding means for feeding a sheet member onto the sheet member conveying passage, and a sheet member conveying means for conveying the sheet member through the sheet member conveying passage. A housing of the image-forming machine has a lower surface defined by an intermediate lower wall and an upper surface defined by an intermediate upper wall, and forms a space of which the front surface is opened. The downstream end portion of the sheet member conveying passage extends along a one side portion of the intermediate lower wall on the lower side thereof. The one side portion of the intermediate lower wall is defined by the opening/closing member, and opening/closing member is brought to the open position to open the downstream end portion of the sheet member conveying passage. The sheet member conveying means includes a pair of register rollers. After the leading edge of the sheet member delivered onto the sheet member conveying passage is brought into contact with the nip of the pair of register rollers, the pair of register rollers are preliminarily rotated for only a predetermined period of time.

Image-forming machine

An image forming machine having a transfer roller comprises a rotatably disposed photoconductor drum, a transfer roller disposed opposite the photoconductor drum with a predetermined gap provided therebetween, a register roller pair for feeding a transfer sheet toward a transfer area where the photoconductor drum and the transfer roller are opposed to each other, transfer sheet guide means disposed between the register roller pair and the transfer area, and a fixing roller pair for fixing a toner image transferred to the transfer sheet passing through the transfer area. The transfer sheet guide means comprises an inner guide plate and an outer guide plate, and the inner guide plate has a linear guide portion extending toward a predetermined position on the peripheral surface of the photoconductor drum. The predetermined position is set in an angular range (.theta.) covering 12.degree. to 23.degree. upstream, in the direction of rotation of the photoconductor drum, from a line connecting the center of rotation of the photoconductor drum to the center of rotation of the transfer roller, while the linear guide portion of the inner guide plate forms an angle (.alpha.) with a tangent to the photoconductor drum at the predetermined position, the angle (.alpha.) being set at 19.degree. to 30.degree..

Image forming machine with transfer roller

An imaging unit includes a developer unit which is supported rotatably about a predetermined rotation axis thereof by means of a drum unit. Spacing regulation sleeves are respectively fitted around opposite ends of a support shaft of a developer roller for regulating a spacing between the photoreceptor drum and the developer roller. A driven gear is engaged with one end of the support shaft of the developer roller for integral rotation thereof, and adapted to be driven by a drive transmission gear. By utilizing a driving force applied to the driven gear, the developer unit is biased about the rotation axis to press one spacing regulation sleeve fitted around one end of the support shaft of the developer roller against the photoreceptor drum. The other spacing regulation sleeve fitted around the other end of the support shaft of the developer roller is resiliently pressed against the photoreceptor drum by means of a resilient member.

Imaging unit

An image forming apparatus according to the present invention comprises three units, that is, an image forming unit 40, a fixing unit 60, and a transfer unit 50. The three units are mounted on a main frame 10 with a positional relationship upon being positioned therebetween. The image forming unit 40 is fixed to a predetermined position with respect to the main frame 10. Further, the main frame 10 comprises a positioning pin 14 arranged in a predetermined positional relationship with the image forming unit 40. The fixing unit 60 and the transfer unit 50 are positioned upon being engaged with the positioning pin 14. Consequently, there is no shift in position among the image forming unit 40, the transfer unit 50, and the fixing unit 60. The three units can be correctly mounted on the main frame 10.

Unit positioning member for an image forming apparatus

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Osaka, Japan

Tetsuya Ichigotani