Claims
- 1. An ink-jet printer for recording with droplets of conductive ink on a recording medium in response to an information signal, said printer comprising:
- a. an ink chamber means filled with said conductive ink, said chamber driving said droplets out of a nozzle in said chamber in response to driving pulses acting directly upon said chamber, the size of said droplets being responsive to the energy content of said driving pulse as they act directly upon the chamber;
- b. means for charging said droplets with a charging voltage after they are driven out of said nozzle; and
- c. means for generating said driving pulse and said charging voltage, said charging voltage and said energy content of said driving pulse having a relationship responsive to said information signal.
- 2. An ink-jet printer for recording with droplets of conductive ink on a recording medium in response to an information signal, said printer comprising:
- a. an ink chamber means filled with said conductive ink;
- b. means responsive to information signals for generating driving pulses, said chamber driving said droplets out of a nozzle in response to said driving pulses, the size of said droplets being responsive to the energy content of said driving pulse;
- c. means for charging said droplets with a charging voltage after they are driven out of said nozzle; and
- d. charging voltage generatng means to vary both said charging voltage and the size of said driving pulse, said charging voltage and said energy content of said driving pulse having a relationship which is fixed responsive to said information signal, whereby the size of said droplets may be changed to produce half-tone pictures responsive to said information signals.
- 3. The printer of claim 2 wherein said driving pulse and charging voltage generator includes a clock pulse generator means for producing cyclically recurring clock pulses, charging voltage generator means for producing said charging voltage; and pulse width modulator means for producing a pulse width modulation signal, the width of said pulse width modulated signal being a function of the level of an input picture signal.
- 4. The printer of claim 2 and means for deflecting said ink droplets after they are driven out of said nozzle and charged responsive to said charging means, and deflection signal source means for generating deflection signals, said deflection signal source means being associated with said generating means, the output signal of said deflection signal source means varying said charging voltage in proportion to said deflection signal.
- 5. The printer of claim 2 wherein said driving pulse and charging voltage generating means includes a variable gain amplifier means for producing said charging voltage, and a deflection signal source means associated with variable gain amplifier means, said variable gain amplifier means varying said charging voltage in response to the output of said deflection signal source means.
- 6. The printer of claim 2 wherein said driving pulse and charging voltage generating means includes a clock pulse generator means, and said charging voltage generating means has a generally sawtooth output waveform, pulse-amplitude modulator means for producing a pulse-amplitude modulated signal jointly responsive to an externally generated picture signal and to clock pulses from said clock pulse generating means, amplitude-component extractor means responsive to said pulse-amplitude modulated signal for producing a control signal, variable delay means for delaying said pulse-amplitude modulated signal for a time period which is determined by the amplitude component of said pulse-amplitude signal, said driving pulse having an energy content established by the duration of said time period.
- 7. The printer of claim 6 wherein said charging voltage has a generally stepped waveform.
- 8. A method of producing half-tone images in an ink-jet printed document comprising the steps of:
- a. a modulating driving pulses responsive to information signals which may contain half-tone information;
- b. forming and charging ink droplets responsive to said modulated driving pulses, the size and charge of said droplet being varied simultaneously and complementary by said driving pulses in order to be jointly constant responsive to said information signals; and
- c. deflecting said droplets responsive to said joint constant of said size and charge on said ink droplets, the deflection of said droplets thus being independent of droplet size, whereby half-tones are produced by variations in droplet size.
- 9. The method of claim 8 wherein step (a) further comprises the added steps of:
- (a-1) amplitude modulating cyclically recurring pulses to produce amplitude variation in said recurring pulses according to the half-tone information in said information signals;
- (a-2) delaying said modulated cyclic pulses for variable time periods corresponding to said amplitude variation;
- and step b. further comprises:
- (b-1) generating a voltage signal responsive to said cyclically recurring pulses, said voltage signal varying with time following each of said cyclically recurring pulses; and
- (b-2) terminating said varying voltage signal responsive to the delay signal of step (a-2) to form said drive pulse, whereby the energy content of said drive pulse is determined by how long said voltage signal may vary between the occurrences of individual ones of said recurring pulses and corresponding ones of said delay signal.
- 10. The method of claim 8 wherein step (a) further comprises the added steps of:
- (a-1) width modulating cyclically recurring pulses to produce time-related variations in said recurring pulses according to the tone information in said information signal; and
- step (b) further comprises:
- (b-1) generating a voltage signal responsive to said cyclically recurring pulses, said voltage signal varying during said time-related variations following each of said cyclically recurring pulses; and
- (b-2) terminating said varying voltage signal responsive to a trailing edge of said width modulated pulse to form said drive pulse, whereby the energy content of said drive pulse is determined by how long said voltage signal may vary over the width of the modulated pulse of step (a-1).
- 11. The method of claim 9 or 10 wherein said varying voltage signal has a sawtooth waveform, beginning at a low voltage responsive to one of said recurring pulses and rising linearly to a high voltage at the start of the next one of said recurring pulses.
- 12. The method of claim 9 or 10 wherein said voltage signal has a stepped waveform beginning at a low voltage responsive to one of said recurring pulses and rising incrementally to a high voltage at the start of the next of said recurring pulses.
- 13. The method of one of the claims 8, 9 or 10 and the further step of arithmetically computing the square of a droplet velocity and modifying the energy content of said drive pulses responsive to said computed velocity.
- 14. An ink jet printer comprising means for supplying charged ink droplets upon demand, means for simultaneously varying the size of and charge upon said droplets in a manner wherein the size and charge have a constant relationship, and means for electrically deflecting said ink droplets responsive to said constant relationship, whereby the printer may print tones by varying the size of said ink droplets.
- 15. The printer of claim 14 and means for computing parameters relating to the path followed by said droplets and means for varying said charge responsive to said computed parameter.
Priority Claims (9)
Number |
Date |
Country |
Kind |
54-16652 |
Feb 1979 |
JPX |
|
54-16653 |
Feb 1979 |
JPX |
|
54-20425 |
Feb 1979 |
JPX |
|
54-33746 |
Mar 1979 |
JPX |
|
54-44020 |
Apr 1979 |
JPX |
|
54-44651 |
Apr 1979 |
JPX |
|
54-55023 |
May 1979 |
JPX |
|
54-55024 |
May 1979 |
JPX |
|
54-55025 |
May 1979 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 120,579, filed Feb. 11, 1980 now U.S. Pat. No. 4,281,333.
US Referenced Citations (4)
Continuations (1)
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Number |
Date |
Country |
Parent |
120579 |
Feb 1980 |
|