Display circuit
AssigneeMosaic Rentals Pty., Ltd.
InventorLeslie C. Harvey
Life of this patent
Estimating the term…
Abstract
A discharge tube opening circuit for varying tube intensity at regular intervals without flicker between an illuminated and an unilluminated state. Combinations of tubes controlled by respective circuits give rise to novel display arrangements through choice of tube colors and particular sequences of variation of luminous intensity.
Claims14
A discharge tube control circuit for progressive and either continuous or intermittent variation of the luminance of one or more discharge tubes in accordance with a programmed sequence whereby the luminance of the tubes is progressively changed between high and low luminance output levels so as to progressively and automatically change the illumination of a visible object illuminated by the tubes, said control circuit comprising:
- (a) control signal generating means having
- (i) an input for a switching signal,
- (ii) switching means actuated by the switching signal to control an RC network having a predetermined charge/discharge rate proportional to the pattern of switching signals,
- (iii) circuit means generating a control signal, and
- (iv) modulating means driven by the RC network and modulating the control signal in response to the pattern of switching signals and the RC network whereby the control signal is progressively varied;
- (b) programming means for the switching signal, said programming means including timer means generating timing pulses of a predetermined frequency giving rise to a predetermined pattern of switching signals;
- and
- (c) a power supply circuit for the discharge tubes and including supply means to fire the tubes and to maintain the tubes in a fired state, power supply varying means responsive to the control signal to vary the power supplied to the tubes in accordance with the changes in the control signal as determined by the programming means.
A discharge tube control circuit for continuously and independently varying the luminance of a number of fluorescent tubes between a high a low luminance level output in accordance with a predetermined programmed sequence, said control circuit comprising:
- (a) a power supply circuit to fire the discharge tubes and to maintain the tubes in a fired state;
- (b) power supply varying means associated with the power supply circuit to automatically vary the power supplied to the tubes in accordance with a control signal to vary the luminance level output of each of the tubes independently;
- (c) control signal generating means for each power supply varying means and having an input for a switching signal an RC network having a predetermined charge/discharge rate proportional to the switching signal pattern circuit means providing a predetermined control signal for the power varying means and modulating means responsive to the RC network to modulate the control signal, said control signal generating means being responsive to the switching signal to progressively vary the control signal;
- and
- (d) programming means for said switching signal to provide a predetermined pattern of switching signals to thereby produce a predetermined variation of luminance level output of the discharge tube.
Dependencies are inferred from the claim text.