US3567923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for monitoring and controlling the color density of ink during printing
Assignee: HURLECTRON Inc
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Filing: 1968-04-03
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Granted: 1971-03-02
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Expires: 1988-04-03
Abstract
Abstract A system for monitoring and controlling the color density of ink applied to a surface of a moving web. A fountain roller receives ink from an ink supply and applies the ink to a printing cylinder which, in turn, applies the ink to the web surface. A sensing device senses the color density of the ink on the web surface and generates a control signal. The control signal is compared with a reference signal to develop an error signal. A storage circuit receives the error signal and, a sampling circuit is connected to the storage circuit to generate a control voltage which controls the amount of ink applied to the printing cylinder.
Inventors
- 👤 Joel F Hutchison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:38
CPC Classifications
B; B41; B41F; B41F33/00; B41F33/0036; B41F33/0045
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
93 words
An apparatus for controlling the color density of ink applied to the surface of a continuously moving web according to claim 1 wherein said error delay circuit includes: a proportional amplifier, a resistor connected in series with the input of said proportional amplifier, a feedback resistor connected between the input and output of said proportional amplifier, said feedback resistor having approximately the same value as said series connected resistor, a capacitor connected in parallel with said feedback resistor, whereby the RC time constant of said feedback resistor and capacitor is approximately 4 seconds.
Claim 2
Dependent Claim
116 words
An apparatus for controlling the color density of ink applied to the surface of a continuously moving web according to claim 1 wherein said sampling circuit includes: a relay coil, a silicon controlled rectifier connected in series with said relay coil, an adjustable frequency oscillator connected to the gate electrode of said silicon controlled rectifier for rendering said silicon controlled rectifier conductive at predetermined spaced intervals; a transistor connected in parallel with said silicon controlled rectifier; and a time duration circuit responsive to the conduction of said silicon controlled rectifier for rendering said transistor conductive at a predetermined time after the conduction of said silicon controlled rectifier, thereby, causing the silicon controlled rectifier to become nonconductive.
Claim 3
Dependent Claim
96 words
An apparatus for controlling the color density of ink applied to the surface of a continuously moving web according to claim 3 wherein said adjustable frequency oscillator is a unijunction transistor oscillator, and wherein said time duration of circuit includes a charging capacitor, a unijunction transistor having the emitter electrode thereof connected to one end of said capacitor and one base electrode thereof connected to the other end of said capacitor whereby, charging of said capacitor to a predetermined voltage will cause the unijunction transistor connected thereto to develop a pulse to render said transistor conductive.
Claim 4
Dependent Claim
148 words
Apparatus for controlling the color density of ink applied to a continuously moving web, comprising: controllable means for applying ink to a fountain roller; a printing cylinder; means for transferring the ink from said fountain roller to said printing cylinder; means for transferring the ink from said printing cylinder to the moving web; means for scanning the ink across the web to provide a signal indicative of average color density, means for comparing said color density signal with a reference signal to produce an error signal for deviations of said average color density signal from said reference signal; circuit means having an upper and a lower threshold defining therebetween a dead band and responsive to an error signal outside of the dead band to produce an ink control signal; and means for applying the ink control signal to said controllable ink applying means for controlling the operation thereof.
Claim 5
Dependent Claim
22 words
Apparatus according to claim 5 further comprising means connected between said comparing means and said circuit means for delaying the error signal.
Claim 6
Dependent Claim
31 words
Apparatus according to claim 6, further comprising sampling means interposed between said delaying means and said circuit means for periodically providing samples of the delayed error signal to said circuit means.
Claim 7
Dependent Claim
66 words
Apparatus according to claim 6 wherein said delaying means includes a proportional amplifier, a resistor connected in series with the input of said amplifier, a feedback resistor connected between the output and the input of said amplifier and having the same value as said series connected resistor, and a capacitor connected in parallel with said feedback resistor to provide a time constant of approximately 4 seconds.
Claim 8
Dependent Claim
80 words
Apparatus according to claim 5, wherein there is an inking system delay time for ink travel between said controllable ink applying means and said printing roller, and an ink transfer delay time for ink travel between said printing roller and said scanning means, and wherein said apparatus comprises error signal delay means for delaying the error signal for an interval to render the transfer delay time and the error signal delay time substantially equal to the inking system delay time.
Claim 9
Dependent Claim
41 words
Apparatus according to claim 9 comprising sampling means interposed between said delay means and said circuit means and operable to provide said circuit means with samples of the error signal periodically at intervals substantially equal to the inking system delay time.
Claim 10
Independent Claim
138 words
A method of controlling the color density of ink applied to a continuously moving web, comprising: applying ink to a fountain roller; transferring the ink to the surface of a printing cylinder; transferring the ink from the printing cylinder to the surface of the moving web; electrically sensing across the web the density of the ink on the surface of the web and generating corresponding color density signals; combining the color density signals to provide an average color density signal; providing a reference potential between a pair of threshold levels; deriving an error signal as a deviation of the average color density signal from the reference potential; delaying the error signal; and adjusting the application of ink to the fountain roller in accordance with the magnitude and polarity of the delayed error signal which exceeds either threshold level.
Claim 11
Dependent Claim
26 words
A method according to claim 11, comprising the step of periodically sampling the delayed error signal for adjusting the application of ink to the fountain roller.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |