EP0608835A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method and apparatus for driving ink jet recording head

Assignee: Seiko Epson Corp

•

Filing: 1994-01-25

•

Granted: —

•

Expires: 2014-01-25

📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The ink jet printing head of the present invention prints image data with ink droplets without impairing print quality or causing the recording paper to be excessively wetted. The ink jet recording head includes pressure producing chambers (5) communicating with nozzle openings (2), and piezoelectric vibrating elements (14) for expanding and contracting the pressure producing chambers (5). Whether print data is graphics image data or text data is judged by a data judging unit, and as a result of the judgment, a time constant of a variable time constant adjusting unit is set to a longer time in the case of printing image data than in the case of printing text data. Accordingly, the pressure producing chambers (5) are caused to expand without undergoing damped oscillation for a time which is longer than the natural vibration cycle of the piezoelectric vibrating element (14) and which specifically corresponds to the print data.

Inventors

👤 Satoru Hosono
👤 Shoichi Hiraide

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-11-02 22:11

CPC Classifications

B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/04; B41J2/045; B41J2/04501; B41J2/04541; B41J2/04581; B41J2/04588; B41J2/04593; B41J2/135; B41J2/14; B41J2/14201; B41J2/14274

Claims Analysis

Total Claims: 5

Claim 1

Independent Claim 141 words

A method for driving an ink jet recording head having a pressure producing chamber communicating with a nozzle opening and a piezoelectric vibrating element for expanding and contracting the pressure producing chamber, the method comprising the steps of: expanding the pressure producing chamber under an initial condition to a predetermined volume over a first time period, the first time period being longer than a natural vibration cycle of the piezoelectric vibrating element and corresponding to a size of an ink droplet to be ejected; maintaining the pressure producing chamber as expanded for a predetermined second period of time with an expansion start time as a reference; and then contracting the pressure producing chamber to the initial condition over a predetermined third time period longer than the natural vibration cycle of the piezoelectric vibrating element, so that the ink droplet is ejected.

Claim 2

Dependent Claim 205 words

An apparatus for driving an ink jet recording head having a pressure producing chamber (5) communicating with a nozzle opening (2) and a piezoelectric vibrating element (14;64) for expanding and contracting the pressure producing chamber (5), especially according to claim 1, the apparatus comprising: drive signal generating means for cyclically generating a first signal for expanding the pressure producing chamber (5) under an initial condition to a first period of time being longer than a natural vibration cycle of the piezoelectric vibrating element (14;64) and being suitable for forming a desired size of ink droplet, a second signal for maintaining the pressure producing chamber (5) as expanded for a predetermined second period of time with an output start time of the first signal as a reference, and a third signal for contracting the pressure producing chamber (5) to the initial condition over a predetermined third period of time longer than the natural vibration cycle of the piezoelectric vibrating element (14;64); and means for selectively applying a drive signal from the drive signal generating means to the piezoelectric vibrating element (14;64); wherein a time period during which the first signal is produced is varied in accordance with the size of the ink droplet to be ejected.

Claim 3

Dependent Claim 80 words

The apparatus for driving an ink jet recording head according to claim 2, further comprising data judging means (40) for judging whether or not data inputted to a print buffer includes graphics image data, and wherein the time for producing the first signal is set to a shorter value in the case of printing text data and to a longer value in the case of printing graphics image data in accordance with a signal from the data judging means (40).

Claim 4

Dependent Claim 39 words

The apparatus for driving an ink jet recording head according to claim 2 or 3, wherein the first, second and third signals are first, second and third voltage wave-forms , respectively, and the drive signal is a voltage signal.

Claim 5

Dependent Claim 51 words

The apparatus for driving an ink jet recording head according to claim 4, wherein the drive voltage signal generating means comprises a charging and discharging circuit comprising variable resistor means and capacitor (47), the time for producing the first voltage wave-form being adjusted by changing value of the variable resistor means.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag

Select Category

Notes (Optional)