Copying apparatus

In a copying apparatus comprising a housing, a photosensitive member disposed within the housing, an image-forming means for forming an image on the photosensitive member, a copying paper conveying passage defined within the housing and extending through a transfer zone where the image formed on the photosensitive member is transferred to a copying paper, a copying paper feed means for feeding a copying paper sheet to the upstream end of the paper conveying passage, a copying paper returning passage defined within the housing, a conveyance control means adapted to be selectively held at a first position for discharging the paper sheet conveyed through the paper conveying passage out of the housing and a second position for conducting said paper sheet to the paper returning passage, and a copying paper receiving and delivering means disposed adjacent to the downstream end of the paper returning passage and being capable of receiving the paper sheet returned through the paper returning passage and delivering the paper sheet to the upstream end of the paper conveying passage in a direction opposite to the direction of the paper returned through the returning passage the improvement of means for enabling said copying paper receiving and deliver means to be employed, when said copying apparatus is in a mode of operation for forming an image on only one surface of a copying paper sheet and said conveyance control means is maintained in said first position thereof blocking passage of the paper sheets to said paper returning passage, as an alternative source of copying paper sheets, separate from said copying paper feed means, for feeding copying paper sheets to said upstream end of said paper conveying passage, said enabling means including a construction of said copying paper receiving and delivering means comprising:

• a copying paper receiving stand constructed to be selectively manually detachably insertable into and removable from said housing at a position to at least partially project outwardly therefrom and to enable, when in said position, copying paper sheets to be manually loaded into said paper receiving stand from the exterior of said housing and to be delivered therefrom to said upstream end of said paper conveying passage;
• and
• said copying paper receiving stand further having means for, when said copying paper receiving stand is in said position and when said copying apparatus is in a mode of operation for forming images on both surfaces of a copying paper sheet fed from said copying paper feed means, receiving paper sheets returned through said paper returning passage such that the thus received paper sheets may be delivered therefrom to said upstream end of said paper conveying passage.

In a copying apparatus comprising a housing, a photosensitive member disposed within the housing, an image-forming means for forming an image on the photosensitive member, a copying paper conveying passage defined within the housing and extending through a transfer zone where the image formed on the photosensitive material is transferred to a copying paper sheet, a copying paper returning passage defined within the housing, a conveyance control means for selectively holding the paper conveyed through the paper conveying passage at a first position for discharging it outside the housing and a second position for conducting it to the paper returning passage, and a copying paper receiving and delivering means disposed adjacent to the downstream end of the paper returning passage and being capable of receiving the paper returned through the paper returning passage and delivering it to the upstream end of the paper conveying passage through the paper delivering passage, the improvement comprising:

• means, provided in said paper delivery passage, for preventing delivery of two or more copying paper sheets at a time, said preventing means comprising a rotatably mounted rotating shaft, a roller mounted on the rotating shaft, a friction pad formed of a material having a high coefficient of friction and mounted movably between an operating position at which it is pressed toward the roller and an inoperative position at which it is spaced from the roller, and a friction pad positioning means for selectively moving the friction pad between the operating position thereof and the inoperative position thereof;
• the paper returning passage extending below the paper conveying passage and the paper delivering passage;
• a plurality of return rollers acting on the upper surface of the copying paper in the downstream end portion of the paper returning passage and mounted in spaced-apart relationship in the widthwise direction on the rotating shaft of the means for preventing delivery of two or more copying paper sheets at a time;
• and
• the housing including a bottom wall of a synthetic resin, a plurality of protrusions defining at least a part of the paper return passage and formed integrally on the upper surface of the bottom wall in spaced-apart relationship, each of the return rollers being arranged to align with a respective one of the protrusions, and by the cooperative action of the returning rollers and the protrusions, the paper is returned through the paper returning passage.

In a copying apparatus comprising a housing, a photosensitive member disposed within the housing, an image-forming means for forming an image on the photosensitive member, a copying paper conveying passage defined within the housing and extending through a transfer zone where the image formed on the photosensitive member is transferred to a copying paper sheet, a copying paper returning passage defined within the housing, a conveyance control means adapted to be selectively held at a first position for discharging the paper sheet conveyed through the paper conveying passage out of the housing and a second position for conducting said paper sheet to the paper returning passage, and a copying paper receiving and delivering means disposed adjacent to the downstream end of the paper returning passage and being capable of receiving the paper sheet returned through the paper returning passage and delivering the paper sheet to the upstream end of the paper conveying passage in a direction opposite to the direction of the paper returned through the returning passage, the improvement wherein:

• the paper receiving and delivering means includes a copying paper receiving stand mounted detachably on the housing and at least partly projecting out of the housing, such that the paper returned through the paper returning passage is received on the paper receiving stand and a copying paper sheet can be manually loaded in the copying paper receiving stand from outside the housing;
• a copying paper delivering passage is disposed within the housing and extends from the paper receiving and delivering means to the upstream end of the paper conveying passage;
• means for preventing delivery of two or more paper sheets at a time includes a rotatably mounted rotating shaft, a roller mounted on the rotating shaft, a friction pad formed of a material having a high coefficient of friction, said pad being mounted so as to move freely between an operating position at which it is pressed toward the roller and an inoperative position at which it is spaced from the roller, and a friction pad positioning means for holding the friction pad selectively at the operating position thereof or at the inoperative position thereof;
• said paper returning passage extends below the paper conveying passage and the paper delivering passage;
• a plurality of return rollers act on the upper surface of the copying paper in the downstream end portion of the paper returning passage and are mounted in spaced-apart relationship in the widthwise direction on the rotating shaft of said means for preventing delivery of two or more paper sheets at a time;
• and
• said housing includes a bottom wall made of a synthetic resin, a plurality of protrusions define the underside of at least a part of the paper returning passage and are formed integrally with the upper surface of the bottom wall in spaced-apart relationship in the widthwise direction, each of the return rollers is arranged in alignment with a respective one of the protrusions, and the copying paper sheet is returned by the cooperative action of the return rollers and the protrusions.

In a copying apparartus comprising a housing, a photosensitive member disposed within the housing, an image-forming means for forming an image on the photosensitive member, a copying paper conveying passage defined within the housing and extending through a transfer zone where the image formed on the photosensitive member is transferred to a copying paper sheet, a copying paper returning passage defined within the housing, a conveyance control means adapted to be selectively held at a first position for discharging the paper sheet conveyed through the paper conveying passage out of the housing and a second position for conducting said paper sheet to the paper returning passage, and a copying paper receiving and delivering means disposed adjacent to the downstream end of the paper returning passage and being capable of receiving the paper sheet returned through the paper returning passage and delivering the paper sheet to the upstream end of the paper conveying passage in a direction opposite to the direction of the paper returned through the returning passage, the improvement comprising:

• the paper receiving and delivering means including a copying paper receiving stand mounted detachably on the housing and at least partly projecting out of the housing, such that the paper returned through the paper returning passage is received on the paper receiving stand and a copying paper sheet can be manually loaded in the copying paper receiving stand from outside the housing;
• said conveyance control means including a plurality of plate members disposed in spaced-apart relationship in the widthwise direction, whereby when the plate members are held at the first position thereof the paper sheets conveyed through the paper conveying passage are discharged out of the housing by being guided by upper edges of the plate members, and when the plate members are held at the second position thereof the paper sheets conveyed through the paper conveying passage are conducted to the paper returning passage by being guided by front edges of the plate members;
• a rotating shaft mounted rotatably above the plate members and a plurality of discharge rollers mounted on the rotating shaft in spaced-apart relationship in the widthwise direction in alignment with the plate members provided within the housing, such that when the plate members are held at the first position thereof the paper conveyed through the paper conveying passage is discharged out of the housing by the cooperative action of the discharge rollers and the upper edges of the plate members;
• copying paper feed means for feeding copying paper sheets to the upstream end of the paper conveying passage;
• manual selection switch means selectively permitting the feeding of paper sheets to the paper conveying passage by the paper feed means and the delivery of paper to the paper conveying passage by the paper receiving and delivering means;
• and
• return obstructing means for permitting the conveyance control means to be selectively held at the first position thereof or the second position thereof when the feeding of paper sheets to the paper conveying passage by the paper feed means is permitted, but for obstructing the positioning of the conveyance control means at the second position thereof when the delivery of paper sheets to the paper conveying passage by the receiving and delivering means is permitted.