Ink jet printer head and printer apparatus

(19)

(11)

EP 1 013 429 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	14.03.2001 Bulletin 2001/11

(43)	Date of publication A2:
	28.06.2000 Bulletin 2000/26

(21)	Application number: 99305770.2

(22)	Date of filing: 21.07.1999

(51)	International Patent Classification (IPC)⁷: B41J 2/14

(84)	Designated Contracting States:
	AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
	Designated Extension States:
	AL LT LV MK RO SI

(30)

Priority:

25.12.1998 JP 37103398

(71)	Applicant: FUJITSU LIMITED
	Kawasaki-shi, Kanagawa 211-8588 (JP)

(72)	Inventors:
	Koike, Shuji, c/o Fujitsu Limited Kawasaki-shi, Kanagawa 211-8588 (JP) Sakamoto, Yoshiaki, c/o Fujitsu Limited Kawasaki-shi, Kanagawa 211-8588 (JP) Shingai, Tomohisa, c/o Fujitsu Limited Kawasaki-shi, Kanagawa 211-8588 (JP)

(74)	Representative: Silverman, Warren et al
	Haseltine Lake & Co. Imperial House, 15-19 Kingsway London WC2B 6UD London WC2B 6UD (GB)

(54)	Ink jet printer head and printer apparatus

(57) A piezo-electric reinforcing member surrounding a plurality of pressure generating units is formed in a thin vibrating chromium film membrane. The reinforcing member is not discrete but continuous with respect to a region of the membrane enclosing the pressure generating units. Within the membrane, thermal stress as well as stress caused by differences in the crystal structure of the piezo-electric member and the chromium film arise. The mechanical strength of the reinforcing member itself restrains the shrinkage of the vibrating membrane caused by the internal stress, thereby preventing cracks from occurring in the vibrating membrane. Likewise, the ends of the pressure generating components as well as the individual electrodes are shaped so as to make it difficult for stress to accumulate thereat, thereby also preventing cracks from occurring in the vibrating membrane.

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