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US4489335A Expired / Lapsed US ⏱️ 0.0 years remaining

Ink jet printing apparatus

Assignee: Konica Minolta Inc
•
Filing: 1982-09-14
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Granted: 1984-12-18
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Expires: 2002-09-14
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Abstract

Abstract An ink jet printing apparatus of the impulse type which has an ejection failure detector. The detector has electrode means for charging ejected droplets, a reception electrode for receiving the charged droplets, and a circuit for detecting the approach and arrival of the charged droplets at the reception electrode. An ejection failure detection causes a nozzle purging operation.

Inventors

  • 👤 Masato Watanabe
  • 👤 Kazuhiro Oda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 12:54
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/165; B41J2/16579

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 175 words
In an ink jet printing apparatus comprising a printing head having at least one nozzle for ejecting an ink droplet to a recording medium and means for moving said printing head along said recording medium, the improvement comprising: (a) an ejection failure detector comprising: (i) electrode means including at least one electrode for charging an ink droplet ejected from each nozzle, the printing head being moved opposite said ejection failure detector to a spit position by said moving means at predetermined time intervals corresponding to a certain number of times of scanning of said recording medium by said printing head, (ii) a reception electrode positioned opposite the printing head and for receiving the charged ink droplet, (iii) a detecting circuit for detecting the approach and arrival of the charged ink droplet at said reception electrode, and (b) means for purging said nozzle by moving said printing head to a purging position by said moving means and causing the ink to be ejected forcibly from said nozzle when said printing head is at said purging position.
Claim 2
Dependent Claim 175 words
In an ink jet printing apparatus comprising a printing head having at least one nozzle for ejecting an ink droplet to a recording medium and means for moving said printing head along said recording medium, the improvement comprising: (a) an ejection failure detector comprising: (i) electrode means including at least one electrode for charging an ink droplet ejected from each nozzle, the printing head being moved opposite said ejection failure detector to a spit position by said moving means at predetermined time intervals corresponding to a certain number of times of scanning of said recording medium by said printing head, (ii) a reception electrode positioned opposite the printing head and for receiving the charged ink droplet, (iii) a detecting circuit for detecting the approach and arrival of the charged ink droplet at said reception electrode, and (b) means for purging said nozzle by moving said printing head to a purging position by said moving means and causing the ink to be ejected forcibly from said nozzle when said printing head is at said purging position.
Claim 3
Dependent Claim 23 words
An ink jet printing apparatus according to claim 1, wherein the movement of the printing head opposite the ejection failure detector occurs automatically.
Claim 4
Dependent Claim 28 words
An ink jet printing apparatus according to claim 1, wherein said apparatus further comprises a position detector for detecting said printing head to be at the spit position.
Claim 5
Dependent Claim 28 words
An ink jet printing apparatus according to claim 1, wherein said apparatus further comprises a position detector for detecting said printing head to be at the purging position.
Claim 6
Dependent Claim 28 words
An ink jet printing apparatus according to claim 1, wherein said ejection failure detector comprises two charging electrodes for passing the ink droplet between said two charging electrodes.
Claim 7
Dependent Claim 37 words
An ink jet printing apparatus according to claim 1, wherein said ejection failure detector further comprises an ink collecting member disposed at the base of the reception electrode and between the charging electrode and the reception electrode.
Claim 8
Dependent Claim 60 words
An ink jet printing apparatus according to claim 1, wherein said printing head comprises an ink chamber, a nozzle communicating with said ink chamber for ejecting an ink droplet to a recording medium, and volume displacement means responsive to electrical signals for displacing a predetermined volume of ink in said chamber to eject from said nozzle a droplet of ink.
Claim 9
Dependent Claim 117 words
In an ink jet printing apparatus comprising a printing head having at least one nozzle for ejecting an ink droplet onto a recording medium and means for moving said printing head in a direction parallel to said recording medium, the improvement comprising: an ejection failure detector for detecting an ejection failure at predetermined time intervals corresponding to a certain number of times of scanning of the recording medium by the printing head, said detector causing an ink droplet ejected from each nozzle to be electrically charged; and means for purging said nozzle by causing the ink to be ejected forcibly from said nozzle after said printing head is moved to a purging position by said moving means.
Claim 10
Dependent Claim 117 words
In an ink jet printing apparatus comprising a printing head having at least one nozzle for ejecting an ink droplet onto a recording medium and means for moving said printing head in a direction parallel to said recording medium, the improvement comprising: an ejection failure detector for detecting an ejection failure at predetermined time intervals corresponding to a certain number of times of scanning of the recording medium by the printing head, said detector causing an ink droplet ejected from each nozzle to be electrically charged; and means for purging said nozzle by causing the ink to be ejected forcibly from said nozzle after said printing head is moved to a purging position by said moving means.

References Cited (Backward Citations)

US4050078A Cited
US4123761A Cited
US4176363A Cited
US4323908A Cited
US4323905A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-12-18 1988-06-18 1988-12-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-12-18 1992-06-18 1992-12-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-12-18 1996-06-18 1996-12-18 $7700.00 Window Closed / Lapsed

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