(19) |
 |
|
(11) |
EP 0 307 160 A3 |
(12) |
EUROPEAN PATENT APPLICATION |
(88) |
Date of publication A3: |
|
10.01.1990 Bulletin 1990/02 |
(43) |
Date of publication A2: |
|
15.03.1989 Bulletin 1989/11 |
(22) |
Date of filing: 06.09.1988 |
|
(51) |
International Patent Classification (IPC)4: B41J 2/17 |
|
(84) |
Designated Contracting States: |
|
CH DE FR GB IT LI NL |
(30) |
Priority: |
11.09.1987 US 96363
|
(71) |
Applicant: DATAPRODUCTS CORPORATION |
|
Woodland Hills
California 91365 (US) |
|
(72) |
Inventors: |
|
- Howkins, Stuart D.
Ridgefield
CT 06877 (US)
- McCormick, John A.
Norwich, VT 05055 (US)
|
(74) |
Representative: Allman, Peter John et al |
|
MARKS & CLERK,
Sussex House,
83-85 Mosley Street Manchester M2 3LG Manchester M2 3LG (GB) |
|
|
|
(54) |
Acoustic microstreaming in an ink jet apparatus |
(57) An ink jet apparatus having a scanning head employing at least one ink jet with a
variable volume chamber which includes an ink droplet ejecting orifice, and a transducer,
having a length mode resonant frequency, adapted to expand and contract along an axis
of elongation in response to an electric field substantially transverse to the axis
of elongation for ejection of droplets on demand from the ink droplet ejecting orifice
is acoustically microstreamed by exciting the transducers during non-printing periods
to eliminate start-up problems and to maintain pigments or other particles in dispersion
within the ink.