Incremental printing of symbolic information – Ink jet – Controller
Patent
1993-06-04
1994-11-29
Fuller, Benjamin R.
Incremental printing of symbolic information
Ink jet
Controller
738659, 73DIG4, 310333, 310338, 340635, 324512, 324718, 324727, B41J 2125, G01D 1800
Patent
active
053694201
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a method of testing multi-channel array pulsed droplet deposition apparatus. Such apparatus of which a typical example is a drop-on-demand ink jet printer, comprises a multiplicity of parallel uniformly spaced channels mutually spaced in an array direction extending normal to the length of the channels and each with pulse imparting means for effecting droplet ejection therefrom.
Channel densities of two or more per millimetre are usual in state of the art drop-on-demand ink jet printers. Accordingly, considerable numbers of channels are employed in the printheads of such printers all of which are required to function satisfactorily to achieve the desired printing performance. It is however, impractical in a production environment because of time constraints to test sequentially the activity of each channel.
One object of the present invention therefore is to provide a method of testing expeditiously, a multi-channel array, pulsed droplet deposition apparatus of the kind set forth, to determine whether the array contains any defective channels.
The present invention consists in the method of testing a multi-channel array pulsed droplet deposition apparatus comprising a multiplicity of parallel channels uniformly spaced in an array direction extending normal to the length of the channels and each with pulse imparting means for effecting droplet ejection therefrom, said method comprising the steps of locating said apparatus opposite a test module having mutually spaced detecting elements with channels of said apparatus respectively opposed and in close proximity to said elements, providing coupling fluid in the channels of said apparatus opposed to said detecting elements and between said detecting elements and the channels opposed thereto, applying test signals to impart energy pulses to said fluid in said channels opposed to said detecting elements thereby to transmit signals through the coupling fluid to the detecting elements and evaluating the performance of said channels to which test signals are applied from the signals detected by the detecting elements.
The invention may be further characterised by mutually spacing said detecting elements at an integral multiple of the channel pitch of the channels of said apparatus, testing said channels opposed to said elements by supplying test signals to the coupling fluid therein, translating said apparatus relatively to said module through a channel pitch to dispose channels of the apparatus adjacent the tested channels in opposed relationship to said detecting elements and testing, by supplying test signals to the coupling fluid therein, the channels disposed by said translation opposite said detecting elements. Suitably, the method includes repeatedly translating until all channels of said apparatus are tested, said apparatus relatively to said module through a channel pitch and after each translation testing, by supplying test signals to the coupling fluid therein, the channels opposed to the detecting elements.
In one form, the method of the invention is characterised by employing detecting elements formed as conductive tracks on a side of a sheet of thickness poled piezo-electric material having an electrode on the side of said sheet remote from said tracks and locating said tracks in opposed relationship to channels of the apparatus being tested.
In another form, the method of the invention is characterised by forming said detecting elements of the test module as parallel channels formed in a sheet of thickness poled piezo-electric material between channel dividing side walls coated on channel facing surfaces thereof with electrode material so that said side walls operate as shear mode detectors. Advantageously this form of the invention is further characterised by locating the channels of the detecting elements opposite and parallel with open topped channels of said apparatus and disposing said coupling fluid in the channels of said test module, the channels of said apparatus facing the channels of said test module and the space
REFERENCES:
patent: 4296421 (1981-10-01), Hara et al.
patent: 4381295 (1983-04-01), Kung et al.
patent: 4381515 (1983-04-01), Bain
patent: 4584590 (1986-04-01), Fischbeck et al.
patent: 4590482 (1986-05-01), Hay et al.
patent: 4768045 (1988-08-01), Koto
patent: 4825227 (1989-04-01), Fischbeck et al.
patent: 4835435 (1989-05-01), Yeung et al.
patent: 4879568 (1989-11-01), Bartky et al.
patent: 4887100 (1989-12-01), Michaelis et al.
patent: 5016028 (1991-05-01), Temple
patent: 5028812 (1991-07-01), Bartky
Ikoma, T. "Method to Detect in Situ Defects in Nozzles in Ink Jet Printers," IBM TDB; vol. 24 No. 3, Aug. 1981; p.
Bobb Alrick
Fuller Benjamin R.
XAAR Limited
LandOfFree
Method of testing multi-channel array pulsed droplet deposition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of testing multi-channel array pulsed droplet deposition , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of testing multi-channel array pulsed droplet deposition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-76392