IMAGE FORMATION DEVICE

• Main Author: FURUTA YASUTOMO
• Format: Patent
• Language: English; Japanese
• Published: 21.05.2020
• Subjects: BASIC ELECTRIC ELEMENTS; CINEMATOGRAPHY; CORRECTION OF TYPOGRAPHICAL ERRORS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; LINING MACHINES; MAGNETOGRAPHY; PERFORMING OPERATIONS; PHOTOGRAPHY; PHYSICS; PRINTING; SELECTIVE PRINTING MECHANISMS; SEMICONDUCTOR DEVICES; STAMPS; TRANSPORTING; TYPEWRITERS

To suppress increase in circuit scale, and to highly accurately control variation in quantity of light in each semiconductor chip.SOLUTION: A light exposure head 106 includes: surface light-emitting element array chips 1-29; and a drive voltage generating part 414 outputting drive voltage to the surface light-emitting element array chips. The drive voltage generating part 414 includes: DAC 1111-1125 which are arranged by corresponding to each of the surface light-emitting element array chips, and output the drive voltage; and DAC 1100 and 1101 which output the maximum and minimum voltage of the drive voltage. The DAC 1111-1125 include: a ladder resistor 1204 to which a plurality of voltage-dividing resistors are connected; and a selector circuit 1205 which is disposed on each terminal of the voltage-dividing resistors in order to connect and disconnect a switch according to an instruction from a CPU 400, and outputs voltage obtained by dividing the voltage from the DAC 1100 and 1101. The CPU 400 controls the switch of the selector circuit 1205 of the DAC 1111-1125, and outputs drive voltage according to a light-emitting quantity of each surface light-emitting element array chip.SELECTED DRAWING: Figure 7 【課題】回路規模の増大を抑えるとともに、半導体チップ毎の光量バラツキを高精度に制御すること。【解決手段】露光ヘッド１０６は、面発光素子アレイチップ１〜２９と駆動電圧を面発光素子アレイチップに出力する駆動電圧生成部４１４とを有し、駆動電圧生成部４１４は、各面発光素子アレイチップに対応して設けられ駆動電圧を出力するＤＡＣ１１１１〜１１２５と駆動電圧の最大、最小電圧を出力するＤＡＣ１１００、１１０１とを有し、ＤＡＣ１１１１〜１１２５は、複数の分圧抵抗が接続されたラダー抵抗１２０４と、分圧抵抗の各端子に設けられスイッチをＣＰＵ４００からの指示で接続、切断し、ＤＡＣ１１００、１１０１からの電圧を分圧した電圧を出力するセレクタ回路１２０５とを有し、ＣＰＵ４００は、ＤＡＣ１１１１〜１１２５のセレクタ回路１２０５のスイッチを制御し、各面発光素子アレイチップの発光光量に応じた駆動電圧を出力する。【選択図】図７