Electrostatic copying process and apparatus

An electrostatic copying apparatus comprising:

• (1) a housing having at its top surface a transparent plate for supporting an original to be copied;
• (2) a rotary drum disposed within the housing and having a photosensitive member on its surface;
• (3) a charging, developing and transferring means which are arranged successively around the rotary drum in the moving direction of the surface of the rotary drum;
• (4) an optical system for projecting the image of the original onto the surface of the rotary drum between the charging means and the developing device, the optical system including a lamp for illuminating the original and a first reflecting mirror, a first support frame on which said lamp and said first reflecting mirror are mounted for directing the lamp toward an original on said transparent plate and for receiving the light reflected from the original, a pair of suspending rods extending substantially horizontally within the housing and on which said support frame is slidably mounted, means connected to said support frame for reciprocating said support frame at a predetermined speed, a second reflecting mirror, a second supporting frame slidably mounted on the suspending rods on which said second reflecting mirror is mounted for receiving light reflected from said first reflecting mirror, said reciprocating means being connected to said second supporting frame for reciprocating it at a speed half of the speed of the reciprocating movement by the first support frame, an in-mirror lens fixed within the housing for receiving light reflected from said second mirror, and a third reflecting mirror fixed within the housing for receiving light from said in-mirror lens;
• a stationary member fixed to one of the suspending rods near one end thereof, and the first reflecting mirror mounted on the first support frame and the second reflecting mirror mounted on the second support frame being positioned in a certain specified relation to each other when the stationary member, a part of the first support frame and a part of the second support frame are caused to abut one another successively when the first and second support frames are moved along the pair of suspending rods to said one end thereof;
• and
• (5) a receptor sheet conveying system for conveying a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring means.

An electrostatic copying apparatus comprising:

• a housing;
• a transparent plate secured to the top surface of the housing for supporting thereon an original to be copied;
• a rotary drum rotatably mounted within the housing and having a photosensitive member on the surface thereof;
• an electrostatic latent image-forming means for forming an electrostatic latent image corresponding to the image of the original on the photosensitive member, said latent image-forming means including an optical system for projecting the image of the original onto the photosensitive member, a developing device for applying a toner to the electrostatic latent image formed on the photosensitive member to form a toner image, said developing device having a developer supply receptacle having end plates and an assembly of a hollow cylindrical sleeve secured between said end plates and to the surface of which a developer is supplied from said supply receptacle and a roll-like permanent magnet mounted within said sleeve;
• a pair of spacer rings having an outside diameter larger than the outside diameter of said hollow cylindrical sleeve by a predetermined amount and rotatably mounted on said hollow cylindrical sleeve adjacent each end thereof and concentric therewith, the surface of said pair of spacer rings contacting the surface of said rotatably drum for setting the distance between the surface of said rotary drum and the surface of said hollow cylindrical sleeve at a predetermined value;
• and a transferring means for transferring said toner image to a receptor sheet;
• and a support means mounted on said housing for sliding in the forward and rearward directions between an operating position within the housing and a pulled-out position outside of the housing, said support having thereon a vertical front plate and a vertical rear plate connected to each other with a predetermined distance therebetween in the forward and rearward directions, each of said plates having two slots therein having one open end and said rotary drum and developing device having support members thereon insertable into said slots for independently detachably mounting said rotary drum and said developing device on said support for being detachable from the support for being moved in a direction substantially at right angles to said forward and rearward direction, said support members being mounted on said assembly and on said two end plates and being inserted into respective pairs of slots for mounting said assembly and said developer supply receptable on said vertical front plate and the vertical rear plate of said support.

An electrostatic copying apparatus comprising:

• a housing;
• a transparent plate secured to the top surface of the housing for supporting thereon an original to be copied;
• a rotary drum rotatably mounted within the housing and having a photosensitive member on the surface thereof;
• an electrostatic latent image-forming means for forming an electrostatic latent image corresponding to the image of the original on the photosensitive member, said latent image-forming means including an optical system for projecting the image of the original onto the photosensitive member, a developing device for applying a toner to the electrostatic latent image formed on the photosensitive member to form a toner image, and a transferring means for transferring said toner image to a receptor sheet;
• and a support mounted on said housing for sliding in the forward and rearward directions between an operating position within the housing and a pulled-out position outside of the housing, said support having thereon a vertical front plate and a vertical rear plate connected to each other with a predetermined distance therebetween in the forward and rearward directions, each of said plates having at least one slot therein having one open end and said rotary drum and developing device having support members thereon insertable into said slots for independently detachably mounting said rotary drum and said developing device on said support for being detachable from the support for being moved in a direction substantially at right angles to said forward and rearward direction;
• and a cleaning device adjacent said drum for removing toner left on the photosensitive member after transferring of the electrostatic latent image, said cleaning device having support members thereon and said vertical front plate and vertical rear plate of said support having a pair of further slots therein with one end opening out of the corresponding plate and in which said cleaning device support members are inserted for detachably mounting said cleaning device on said support by movement in a direction substantially at right angles to said forward and rearward direction, said cleaning device consisting of a support frame, an assembly of a hollow cylindrical sleeve mounted on said support frame and a roll-like permanent magnet disposed within said sleeve, and a toner receptable mounted on said support for receiving toner removed from the surface of said sleeve;
• said cleaning device support members being mounted on said assembly and on said support frame;
• said vertical plates on said support each having two further slots therein and said cleaning device support members being inserted into respective pairs of further slots for mounting said assembly and said support frame on said vertical front plate and the vertical rear plate of said support;
• and a pair of spacer rings having an outside diameter larger that the outside diameter of the hollow cylindrical sleeve by a predetermined amount rotatably mounted on said hollow cylindrical sleeve adjacent each end thereof and concentric therewith, the surfaces of said pair of spacer rings contacting the surface of said rotary drum for setting the distance between the surface of said rotary drum and the surface of the hollow cylindrical sleeve at a predetermined value.

An electrostatic copying apparatus comprising:

• (1) a housing having at its top surface a transparent plate for supporting an original to be copied;
• (2) a rotary drum disposed within the housing and having a photosensitive member on its surface;
• (3) a charging, developing and transferring means which are arranged successively around the rotary drum in the moving direction of the surface of the rotary drum;
• (4) an optical system for projecting the image of the original onto the surface of the rotary drum between the charging means and the developing means, and
• (5) a receptor sheet conveying system for conveying a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring means, the receptor sheet conveying system including:
• (a) at least one paper supplying cassette, said cassette having a substantially rectangular parallelpipedal case with an open top for holding therein a relatively rigid auxiliary bottom plate and a layer of receptor sheets of a predetermined size on the auxiliary bottom plate, said case having a pair of linking lever receiving recesses therein on both sides of the forward end of the case and a receptor sheet lifting lever opening positioned centrally near the forward end of the bottom plate of the case;
• (b) at least one cassette-receiving section for receiving the forward end of the cassette through an opening on the side wall of the housing, said cassette-receiving section having a receiving member with a cassette bottom guiding portion and a cassette forward end abutting portion, a paper feed roller disposed rotatably above the cassette bottom guiding portion and adapted to be selectively rotated, a shaft disposed rotatably adjacent and inside the cassette forward end abutting portion, an elastic means connected to said shaft and biasing said shaft to a first angular position or a second angular position, a pair of cassette linking levers fixed to the shaft and spaced therealong for fitting into the pair of receiving recesses in the cassette when, with the shaft at the first angular position, the cassette is placed on the bottom guiding portion and inserted into the cassette receiving section so that its forward end is brought to a position at which it contacts the cassette forward end abutting portion, and a receptor sheet lifting lever mounted on the shaft at a position between the pair of cassette linking levers, the forward end of the lifting lever being locked at a position retracted from the receptor sheet lifting lever opening when the shaft is at the first angular position;
• and (c) a receptor sheet conveying system for conveying a receptor sheet feed from the cassette through the transfer station, whereby when the shaft is turned from the first position to the second position by rotating the inserted paper supplying cassette in a direction in which its forward end moves upward, the forward end of the lifting lever is unlocked and projects upward from the lifting lever receiving opening of the cassette, and lifts the auxiliary bottom plate and the receptor sheet layer, and urges the topmost receptor sheet of the receptor sheet layer against the paper feed roller for feeding the topmost receptor sheet to said receptor sheet conveying system.

A method of assemblying an electrostatic copying apparatus having:

• (1) a housing having at its top surface a transparent plate for supporting an original to be copied;
• (2) a rotary drum disposed within the housing and having a photosensitive member on its surface;
• (3) a charging, a developing and a transferring means which are arranged successively around the rotary drum in the moving direction of the surface of the rotary drum;
• (4) an optical system for projecting the image of the original onto the surface of the rotary drum between the charging means and the developing device, the optical system including a lamp for illuminating the original and a first reflecting mirror, a first support frame on which said lamp and said first reflecting mirror are mounted for directing the lamp toward an original on said transparent plate and for receiving the light reflected from the original, a pair of suspending rods exending substantially horizontally within the housing and on which said support frame is slidably mounted, means connected to said support frame for reciprocating said support frame at a predetermined speed, a second reflecting mirror, a second supporting frame slidably mounted on the suspending rods on which said second reflecting mirror is mounted for receiving light reflected from said first reflecting mirror, said reciprocating means being connected to said second supporting frame for reciprocating it at a speed half of the speed of the reciprocating movement of the first support frame, an in-mirror lens fixed within the housing for receiving light reflected from said second mirror, and a third reflecting mirror fixed within the housing for receiving light from said in-mirror lens;
• a stationary member fixed to one of the suspending rods near one end thereof, and the first reflecting mirror mounted on the first support frame and the second reflecting mirror mounted on the second support frame being positioned in a certain specified relation to each other when the stationary member, a part of the first support frame and a part of the second support frame are caused to abut on another successively when the first and second support frames are moved along the pair of suspending rods to said one end thereof;
• and
• (5) a receptor sheet conveying system for conveying a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring means;
• said method comprising, after assembling the foregoing elements, temporarily mounting a semi-transparent member on which an image can be made visible and at a position near the periphery of the housing for receiving light reflected from said in-mirror lens, the optical distance from the position of said plate to the third reflecting mirror being the same as the optical distance from the surface of the rotary drum to the third reflecting mirror, and adjusting said optical system for focusing an image of an original thereon from said transparent plate, whereby the optical system is adjusted for properly focusing an image on the rotary drum.