Image forming system using digital ASIC and analog ASIC for processing image data and controlling semiconductor laser, and half-tone pixel representing method
First Claim
1. An image forming system for forming an image comprising respective pixels, comprising:
- a semiconductor laser for emitting light as a light output;
a digital ASIC responsive to pixel data representing said respective pixels and comprising a pulse width modulator which modulates a pulse width and generates a pulse width modulation output signal in accordance with said pixel data; and
an analog ASIC responsive to said pulse width modulation output signal of said digital ASIC and comprising a power modulator which modulates a pulse amplitude so as to generate a modulated laser control signal for said semiconductor laser;
wherein the pulse width modulation output signal of said digital ASIC and the laser control signal of said analog ASIC control said semiconductor laser so as to pulse-width-modulate and amplitude-modulate the light emitted by said semiconductor laser that may be pulse-width-modulated and amplitude-modulated.
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Accused Products
Abstract
A digital ASIC inputs pixel data thereto and an analog ASIC inputs the output signal of the digital ASIC thereto. A combination of the digital ASIC and the analog ASIC controls a semiconductor laser so as to pulse-width-modulate and amplitude-modulate the light emitted by the semiconductor laser that may be pulse-width-modulated and amplitude-modulated. The digital ASIC comprises a reference pulse generator having delay time control unit and a pulse width generator for generating a plurality of different pulse widths using pulses having a plurality of phases generated by the reference pulse generator. The analog ASIC comprises control/modulation unit for controlling the semiconductor laser so as to pulse-width-modulate and amplitude-modulate the light emitted by the semiconductor laser using the plurality of different pulse widths generated by the pulse width generator. The reference pulse generator comprises an oscillator comprising combined multiple delay-time control unit, and control unit for controlling the oscillator so as to make the frequency supplied by the oscillator identical to the clock of the pixel data.
108 Citations
26 Claims
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1. An image forming system for forming an image comprising respective pixels, comprising:
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a semiconductor laser for emitting light as a light output; a digital ASIC responsive to pixel data representing said respective pixels and comprising a pulse width modulator which modulates a pulse width and generates a pulse width modulation output signal in accordance with said pixel data; and an analog ASIC responsive to said pulse width modulation output signal of said digital ASIC and comprising a power modulator which modulates a pulse amplitude so as to generate a modulated laser control signal for said semiconductor laser; wherein the pulse width modulation output signal of said digital ASIC and the laser control signal of said analog ASIC control said semiconductor laser so as to pulse-width-modulate and amplitude-modulate the light emitted by said semiconductor laser that may be pulse-width-modulated and amplitude-modulated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A half-tone pixel representing method comprising the steps of:
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a) controlling a width of a pulse according to pixel data representing respective pixels so as to control a tone of each respective pixel generally; and b) controlling an amplitude of a partial-width portion of said pulse, the amplitude of a remaining-width portion of said pulse being predetermined, according to said pixel data, so as to finely control said tone of each respective pixel. - View Dependent Claims (24, 25, 26)
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Specification