Image forming apparatus having driving means at each end of array and power feeding substrate outside head housing

• US 5,600,363 A
• Filed: 11/03/1993
• Issued: 02/04/1997
• Est. Priority Date: 12/28/1988
• Status: Expired due to Term

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Murano, Shunji, Nishiguchi, Yasuo, Orito, Sadayuki, Kurazono, Yuuji, Arai, Moriyuki, Anzaki, Toshihiro
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): YOCKEY, DAVID F
• Application Number:
  US08/148,522
• Time in Patent Office: 1,189 Days
• Field of Search: 370/113, 345/55, 345/82, 345/204, 347/145, 347/237, 347/238, 347/130, 347/132, 347/180, 347/181, 347/182, 347/13, 347/211
• US Class Current: 347/237
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays

Abstract

An optical print head in an image forming apparatus includes linearly arranged blocks and integrated circuits for driving disposed at one or both ends of the line of blocks. Each of the blocks includes a plurality of light emitting diodes. Positionally corresponding light emitting diodes in each block are connected to one of a plurality of meandering individual signal lines which are connected to the integrated circuits and each block is further connected to a corresponding common signal electrode to which power is selectively applied, thereby making possible illumination and drive of light emitting diodes in each block. The head may include a housing containing the blocks, individual signal lines and common signal electrodes and further include a flexible substrate located outside of the housing connected to and supplying power to the common signal electrodes.

Claims

1. An image forming apparatus comprising:

printing means for forming an image on a recording medium, said printing means having an array of printing blocks, said array having two opposed ends, and a plurality of individual signal lines, each of said individual signal lines having a first end and a second end, wherein

each of said blocks contains a plurality of printing elements arranged in an order in a row, and a common signal line, each of said printing elements having a first terminal and a second terminal,

each of said individual signal lines is connected to the first terminal of one of said printing elements of each of said blocks such that the printing elements connected to one of said individual signal lines are disposed at symmetric positions on adjacent printing blocks, and

the second terminal of said plurality of printing elements in each of said blocks is connected to said common signal line of the respective one of said blocks;

data generating source means for sequentially generating printing data for said printing means in a sequence corresponding to the order of printing elements of each of said blocks;

block selecting means connected between said data generating source means and said common signal lines for selecting each of said blocks in sequence; and

first driving means and second driving means each disposed at a respective end of said array of printing blocks and connected to said data generating source means, each said driving means for providing drive signals simultaneously to all printing elements of each of said blocks, wherein

said first driving means has outputs connected to said first end of each of said individual signal lines and said second driving means has outputs connected to said second end of each of said individual signal lines so that both of said driving means simultaneously supply power to selected printing elements of one of said blocks corresponding to said drive signals and in response to printing data generated by said data generating means when said one of said blocks is selected by said block selecting means.

2. An image forming apparatus comprising:

an electrically insulating wiring substrate having an upper surface;

a power feeding wiring substrate for supplying driving electric power;

a plurality of light-emitting element arrays disposed above said electrically insulating wiring substrate, each of said arrays having a plurality of light-emitting elements arranged in a straight line, said arrays being disposed adjacent one another so that said light-emitting elements of all of said arrays are arranged in a common straight line;

a plurality of individual signal lines mounted on said upper surface of said electrically insulating wiring substrate, wherein said individual signal lines extend parallel to one another along a path which generally follows said common straight line and which is composed of a series of U-shaped portions which are curved in alternately opposite directions transverse to said common straight line, and each of said individual signal lines is connected to a respective one of said light-emitting elements of each of said arrays;

a plurality of common signal electrodes mounted on said upper surface of said electrically insulating wiring substrate at locations spaced from said individual signal lines, so that said common signal electrodes and said individual signal lines are in a common plane on said upper surface of said electrically insulating wiring substrate, said common signal electrodes extending into regions enclosed in the common plane by said individual signal lines at said U-shaped portions of said path, and each of said common signal electrodes being connected to said light-emitting elements of a respective one of said arrays and to said power feeding wiring substrate, wherein all of said common signal electrodes are disposed entirely to one side of said common straight line; and

a housing containing said plurality of light-emitting element arrays, said plurality of individual signal lines and said plurality of common signal electrodes, and wherein said power feeding wiring substrate is located outside of said housing and comprises at least one flexible film and a plurality of flexible thin-film conductors carried by said thin film, each of said flexible thin-film conductors being connected to a respective one of said common signal electrodes.