EP0124190A2
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Method of generating an N-tone gray scale with a thermal ink jet printer, and apparatus therefor
Assignee: HP Inc
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Filing: 1984-01-26
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Granted: —
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Expires: 2004-01-26
Abstract
Abstract A thermal ink jet printer (1) emits discrete drops of a variable volume in order to create a printed gray scale. A pulse train of packets of pulses (Figure 3) is used to generate drops comprising packets of connected or merged droplets; the reciprocal of the pulse repetition rate is greater than the bubble collapse time and the pulse packet rate is less than the maximum single droplet emission rate of the print head. The individual droplets within the packet merge in flight to create a single drop whose volume depends upon the number of pulses contained within the pulse packet. The summing of impulses generated by the individual pulses is also useful so that drops of ink may be emitted by a resistor (5) which is physically undersized for the particular ink being used.
Inventors
- 👤 Christopher A. Tacklind
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:37
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/21; B41J2/2121; B41J2/2128; H; H04; H04N; H04N1/00; H04N1/024; H04N1/032; H04N1/034; B41J2202/00; B41J2202/01; B41J2202/06
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
153 words
Apparatus for applying a train of current pulse packets to a thermal ink jet printer (1), comprising: a controller (47) for issuing a control signal; and characterized by first generation means (51), coupled to the controller, for generating control pulses at a predetermined rate, for receiving the control signal, and for generating control pulses having widths determined from the control signal; and, second generation means (53), coupled to the first generation means at an input and to the thermal ink jet printer at an output, for receiving the control pulses and for presenting packets of current pulses at the output, said packets of current pulses having a preselected pulse repetition rate greater than the reciprocal of a droplet break-off interval of the thermal ink jet printer, having a pulse packet rate determined from the control pulse rate, and having a number of pulses per packet determined from the width of the control pulse.
Claim 2
Dependent Claim
153 words
Apparatus for applying a train of current pulse packets to a thermal ink jet printer (1), comprising: a controller (47) for issuing a control signal; and characterized by first generation means (51), coupled to the controller, for generating control pulses at a predetermined rate, for receiving the control signal, and for generating control pulses having widths determined from the control signal; and, second generation means (53), coupled to the first generation means at an input and to the thermal ink jet printer at an output, for receiving the control pulses and for presenting packets of current pulses at the output, said packets of current pulses having a preselected pulse repetition rate greater than the reciprocal of a droplet break-off interval of the thermal ink jet printer, having a pulse packet rate determined from the control pulse rate, and having a number of pulses per packet determined from the width of the control pulse.
Claim 3
Dependent Claim
41 words
Apparatus according to claim 1, characterized in that the second generation means can produce the packets of current pulses at a rate which is less than or equal to a maximum single droplet emission rate of the thermal ink jet printer.
Claim 4
Dependent Claim
45 words
Apparatus according to either one of claims 1 and 2, characterized in that the second generation means can produce the pulses at a preselected current pulse repetition rate which is greater than the reciprocal of the droplet break-off interval of the thermal ink jet printer.
Claim 5
Dependent Claim
34 words
Apparatus according to any one of the preceding claims, characterized in that the second generation means is arranged to produce the current pulses so that they are located contiguously within the current pulse packet.
Claim 6
Dependent Claim
33 words
Apparatus according to any one of the prececeding claims characterized in that the second generation means produces a pulseless blanking interval between current pulse packets which is greater than the droplet break-off interval.
Claim 7
Dependent Claim
45 words
Apparatus according to any one of the preceding claims characterized in that the number of current pulses per packet multiplied by the current pulse packet rate is less than or equal to the reciprocal of a bubble collapse time of the thermal ink jet printer.
Claim 8
Dependent Claim
17 words
Apparatus according to any one of the preceding claims characterized in that the controller comprises a microprocessor.
Claim 9
Dependent Claim
26 words
Apparatus according to any one of the preceding claims characterized in that the number of current pulses per packet is less than or equal to 16.
Claim 10
Dependent Claim
51 words
Apparatus according to any one of the preceding claims, characterized in that the second generation means produces a current pulse rate which is less than the reciprocal of a bubble collapse time of the thermal ink jet printer and greater than a droplet recede time of the thermal ink jet printer.
Claim 11
Independent Claim
99 words
A method of generating an N-tone printed gray scale with a thermal ink jet printer, characterized by the steps of: determining a desired number of pulses to provide a packet of pulses required to create a dot having a desired darkness tone; delaying for a blanking interval after application of a previous packet to the thermal ink jet printer; generating a packet containing the desired number of pulses and having a pulse repetition rate greater than the reciprocal of a droplet break-off interval for the thermal ink jet printer; and, applying the packet to the thermal ink jet printer.
Claim 12
Independent Claim
99 words
A method of generating an N-tone printed gray scale with a thermal ink jet printer, characterized by the steps of: determining a desired number of pulses to provide a packet of pulses required to create a dot having a desired darkness tone; delaying for a blanking interval after application of a previous packet to the thermal ink jet printer; generating a packet containing the desired number of pulses and having a pulse repetition rate greater than the reciprocal of a droplet break-off interval for the thermal ink jet printer; and, applying the packet to the thermal ink jet printer.
Claim 13
Dependent Claim
25 words
A method according to claim 10, characterized in that the blanking interval is greater than a droplet break-off interval of the thermal ink jet printer.
Claim 14
Dependent Claim
66 words
A method according to claim 11, characterized in that the steps are repeated a plurality of times to generate a plurality of packets and a plurality of drops; the packets are repeated at a pulse packet rate; and, the pulse packet rate multiplied by an integer N is less than or equal to the reciprocal of a bubble collapse time of the thermal ink jet printer.
Claim 15
Dependent Claim
31 words
A method according to claim 12, characterized in that the pulse packet rate is less than or equal to a maximum single droplet emission rate of the thermal ink jet printer.
Claim 16
Dependent Claim
17 words
A method according to claim 13, characterized in that the pulses are located contiguously within the packet.
Claim 17
Independent Claim
94 words
A method of generating an ink drop with a thermal ink jet printer, characterized by the steps of: determining a required number of pulses necessary to cause emission of the drop; generating a pulse packet containing the required number of pulses at a pulse repetition rate which is less than the reciprocal of a bubble collapse time of the thermal ink jet printer and greater than the reciprocal of an ink recede time of the thermal ink jet printer; and, applying the pulse packet to ink-drop producing means of the thermal ink jet printer.
Claim 18
Independent Claim
94 words
A method of generating an ink drop with a thermal ink jet printer, characterized by the steps of: determining a required number of pulses necessary to cause emission of the drop; generating a pulse packet containing the required number of pulses at a pulse repetition rate which is less than the reciprocal of a bubble collapse time of the thermal ink jet printer and greater than the reciprocal of an ink recede time of the thermal ink jet printer; and, applying the pulse packet to ink-drop producing means of the thermal ink jet printer.
Claim 19
Dependent Claim
46 words
A method according to claim 15, characterized in that the steps are repeated a plurality of times to cause emission of a plurality of drops and to provide a blanking interval greater than or equal to a droplet break-off interval of the thermal ink jet printer.
References Cited (Backward Citations)
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