Print head substrate, print head using the same, and printing apparatus

(19)

(11)

EP 0 927 635 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	08.09.1999 Bulletin 1999/36

(43)	Date of publication A2:
	07.07.1999 Bulletin 1999/27

(21)	Application number: 99200744.3

(22)	Date of filing: 02.09.1994

(51)	International Patent Classification (IPC)⁶: B41J 2/05

(84)	Designated Contracting States:
	DE FR GB IT

(30)

Priority:

03.09.1993 JP 21978693

(62)	Application number of the earlier application in accordance with Art. 76 EPC:
	94306488.1 / 0641655

(71)	Applicant: CANON KABUSHIKI KAISHA
	Tokyo (JP)

(72)	Inventors:
	Imanaka, Yoshiyuki, c/o Canon Kabushiki Kaisha Tokyo (JP) Furukawa, Tatsuo, c/o Canon Kabushiki Kaisha Tokyo (JP) Hayasaki, Kimiyuki, c/o Canon Kabushiki Kaisha Tokyo (JP) Maru, Hiroyuki, c/o Canon Kabushiki Kaisha Tokyo (JP) Izumida, Masaaki, c/o Canon Kabushiki Kaisha Tokyo (JP)

(74)	Representative: Beresford, Keith Denis Lewis et al
	BERESFORD & Co. 2-5 Warwick Court High Holborn London WC1R 5DJ London WC1R 5DJ (GB)


	Remarks:
	This application was filed on 11 - 03 - 1999 as a divisional application to the application mentioned under INID code 62.

(54)	Print head substrate, print head using the same, and printing apparatus

(57) The present invention is directed to resolve the noise problem with the ink in an ink jet head without changing the substrate manufacturing process for the ink jet head, that is, increasing the cost on the manufacture, and without needs of disposing a noise countermeasure component on the side of the printer main device, or making the design change for the countermeasure. The present invention is characterized in that to prevent malfunction from arising by the noise, a hysteresis circuit l0l to provide different input data threshold values upon rising and falling is provided on an input portion of the signal for a drive control logic system such as a drive input signal for a shift register 404 and a latch circuit 403 on the same substrate as that of the heating elements 40l, the driver 402 and the drive control logic circuit, utilizing a diffusion layer constituting a driver 402.

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