Facsimile transmission apparatus using plain paper sheets and method for assembling the facsimile transmission apparatus

A facsimile transmission apparatus for plain paper sheets using an electrophotographic developing system, said apparatus comprising:

• a lower frame having an open top portion, said lower frame being molded to accommodate assembly within said lower frame of a developing device for selectively attaching toner to indicate a visible charging image on a photosensitive drum, a transfer device for transferring the visible charging image from said photosensitive drum to one of the paper sheets, a pickup roller for picking up the paper sheets, and a conveyor roller for conveying the paper sheets to said developing device;
• an upper frame rotatably coupled to said lower frame, said upper frame being molded to accommodate assembly within said upper frame of an exposure unit, a fixing unit and a photosensitive drum configuration comprising said photosensitive drum and a charging device;
• a supporting device coupled to said upper frame for supporting said exposure unit;
• first bars elastically installed on said lower frame to position said exposure unit a predetermined distance from an outer circumference of said photosensitive drum when said upper frame is rotated to engage said lower frame;
• and
• second bars elastically installed on said lower frame to maintain a constant distance between the outer circumference of said photosensitive drum and a center axis of a magnetic roller of said developing device when said upper frame is rotated to engage said lower frame.

A facsimile transmission apparatus, comprising:

• a lower frame;
• an upper frame rotatably-coupled to said lower frame;
• a photosensitive drum configuration having a photosensitive drum connected to said upper frame;
• an exposure device for enabling formation of an electrostatic latent image on said photosensitive drum by selectively exposing light onto said photosensitive drum;
• a support frame connected to said upper frame for supporting said exposure device;
• pressure supporting bars elastically installed on said lower frame for engaging said support frame to maintain a constant optimal distance between said exposure device and said photosensitive drum when said upper frame is rotated to engage said lower frame;
• and
• position sensing springs connected to said upper frame for maintaining said photosensitive drum assembly at a predetermined position relative to said upper frame.

A facsimile transmission apparatus, comprising:

• an upper frame having first and second guide members;
• a photosensitive drum assembly having a photosensitive drum for receiving toner to form a toner image, said photosensitive drum assembly being inserted into said first and second guide members of said upper frame;
• a developing device for providing the toner to said photosensitive drum;
• and
• pressure springs connected to said photosensitive drum assembly for respectively engaging and applying pressure upon supporting ribs of said developing device.

A facsimile transmission apparatus using an electrophotographic developing system, said apparatus comprising:

• an upper frame molded to accommodate installation of a photosensitive drum configuration comprising a photosensitive drum and a charging device;
• a lower frame rotatably connected to said upper frame;
• pressure sensing springs connected to said upper frame for maintaining said photosensitive drum assembly at a predetermined position relative to said upper frame;
• and
• a locking bracket connected to said upper frame, said locking bracket having a hook portion that latches to a shaft on said lower frame, said locking bracket being elastically supported on one end by a tension coil spring on said upper frame to enable said locking bracket to resiliently attach to said shaft.

A facsimile transmission apparatus using an electrophotographic developing system, said apparatus comprising:

• an upper frame molded to accommodate installation of a photosensitive drum assembly having a photosensitive drum and a pair of position sensing springs;
• a lower frame rotatably connected to said upper frame and having a funnel-shaped inlet;
• and
• a developing device having a magnetic roller for supplying toner to said photosensitive drum and a guide pole extending outwardly from first and second mutually opposing sides of said developing device, said guide pole being inserted into said funnel-shaped inlet of said lower frame to install said developing device within said apparatus.

A method for assembling components of a facsimile apparatus having a lower frame, an upper frame rotatably-coupled to said lower frame and a base frame, said method comprising the steps of:

• attaching a bracket for supporting a paper cassette to a bottom portion of said lower frame;
• inserting said lower frame into said base frame using a guide rib on said base frame as a reference;
• assembling a hinge shaft onto said lower frame to enable rotation of said upper frame about said lower frame;
• mounting said paper cassette in said bracket;
• assembling a guide plate into said bottom portion of said lower frame, said guide plate for delivering paper sheets from said paper cassette to a developing device;
• inserting a first shaft supporting a roller disposed to pickup the sheets of paper from said paper cassette into a groove formed in said lower frame;
• securing said first shaft by inserting a bearing onto said first shaft on a top portion of said groove;
• inserting said developing device into a guide opening conforming to receive said developing device on said lower frame to position said developing device on a top portion of said pickup roller;
• inserting a photosensitive drum assembly into a guide member conforming to receive said photosensitive drum assembly on said upper frame;
• positioning a frame for supporting an exposure device on said upper frame between said photosensitive drum assembly and said developing device by inserting assembling pins into an assembling hole on said upper frame;
• and
• rotating said upper frame about said lower frame to position said upper frame on top of said lower frame while a first rib extending from said photosensitive drum assembly engages a second rib positioned on said developing device causing a cover of said developing device to open.