Patent Number: 6,169,528

Title: Electron generating device, image display apparatus, driving circuit therefor, and driving method

Abstract: In order to prevent voltage drops across the wiring resistances in a multi-electron source having a plurality of electron emitters wired in the form of a matrix through a plurality of data wiring layers and a plurality of scanning wiring layers, a constant current signal is output to each data wiring layer. At this time, each non-selected data wiring layer tends to be set at a high impedance and vary in potential, resulting in an abnormal turn-on operation or an electron orbit shift. A driving circuit for solving this problem is provided. A switch for switching a constant current output unit for outputting a constant current regardless of the impedance of a signal output destination, and a constant voltage output unit for outputting a constant voltage regardless of the impedance of a signal output destination is connected to each data wiring layer. For example, a constant-current circuit (17) as a current output unit always outputs the same current (I1 to In) to a switch (30). A pulse width signal (PW1 to PWn) from a pulse-width modulation circuit (7) serves to switch the mode of outputting a current (I1 to In) to a data wiring layer (D.sub.y1 to D.sub.yn) and the mode of fixing a data wiring layer to voltage GND.

Inventors: Oguchi; Takahiro (Yamato, JP), Suzuki; Hidetoshi (Fujisawa, JP), Sakai; Kunihiro (Isehara, JP), Sakuragi; Takamasa (Hiratsuka, JP), Todokoro; Yasuyuki (Yokohama, JP)

Assignee: Canon Kabushiki Kaisha

International Classification: G09G 3/22 (20060101); G09G 003/22 ()

Expiration Date: 01/02/2018