EP0482866A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Densitometer and circuitry for measuring marking particle density on a photoreceptor
Assignee: Xerox Corp
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Filing: 1991-10-21
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Granted: —
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Expires: 2011-10-21
Abstract
Abstract A densitometer for an electrographic apparatus achieves improved measuring of marking particle density on a photoreceptor (10) or the like. Use of a charge-coupled device (CCD) (99) allows for a pixel-by-pixel recordation of the photo intensity (97, 98) reflected off the photoreceptor and toner test patch (95). As a result of the increased sensitivity of the toner measuring, it is possible to measure denser patches of toner, both black as well as color, thus allowing for accurate monitoring of the amount of toner placed onto a photoreceptor.
Inventors
- 👤 Michael A. Butler
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 16:41
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5033; G03G15/5041; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/4738; G01N2021/4764; G01N2021/4769; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00037; G03G2215/00042
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
60 words
A densitometer including a reflectance sensor circuitry, adapted to receive light reflected from the member, comprising: a) means for receiving at least a portion of said reflected light, said receiving means generating a signal responsive thereto; b) means for storing said signal generated by said receiving means; and c) means for actuating said storage means to transmit said signal therefrom.
Claim 2
Dependent Claim
42 words
A densitometer according to claim 1, wherein said receiving means comprises a plurality of discrete photosites arranged in a matrix array, wherein each of said photosites develops an individual signal proportional to the amount of light received by each of said photosites.
Claim 3
Dependent Claim
32 words
A densitometer according to claim 2, wherein said actuating means comprises an interline transfer architecture having vertical and horizontal output transport registers coupled to said photosites to transmit the individual signals therefrom.
Claim 4
Dependent Claim
36 words
A densitometer according to claim 3, wherein: said light source has a de-energized and energized state; and said sensor circuitry includes intensity controlling means for controlling the intensity of said light source during said de-energized state.
Claim 5
Dependent Claim
50 words
A densitometer according to claim 4, wherein said intensity controlling means comprises: a) means for producing a first signal from said light during said energized state; and b) means for producing a second signal from said first signal, wherein said second signal adjusts said light source during said de-energized state.
Claim 6
Dependent Claim
71 words
A densitometer according to claim 5, wherein said first signal producing means comprises: a) a photodiode for receiving said emitted light; b) an operational amplifier, receiving an output signal from said photodiode, for creating an amplified signal from said photodiode output signal; and c) an analog to digital converter, receiving an amplified output signal from said operational amplifier, for converting said amplified output signal to a corresponding linearly stepping digital signal.
Claim 7
Dependent Claim
80 words
A densitometer according to claim 6, wherein said second signal producing means comprises: a) a microcontroller receiving an output signal from said analog to digital converter; b) a digital to analog converter receiving an output signal from said microcontroller; c) a light intensity controller receiving an output signal from said digital to analog converter and said operational amplifier; and d) a light intensity drive circuitry, for driving the intensity of said light source in response to said light intensity controller.
Claim 8
Dependent Claim
20 words
A densitometer according to claim 2, which further includes means for processing said proportional individual signals from said activation means.
Claim 9
Dependent Claim
100 words
A densitometer in accordance with claim 8, wherein said signal processing means comprises: a) means for processing a first signal, responsive to said actuating means; b) means for processing a second signal, responsive to said first processing signal, comprising at least first and second component signals; c) means for processing a third signal, responsive to said second processing signal, for communicating said at least two component signals to a main computing system; and d) means for processing a fourth signal, responsive to said third processing signal, for coordinating timing of proper activation of said light source and said reflectance sensor.
Claim 10
Dependent Claim
46 words
A densitometer in accordance with claim 9, wherein said first processing signal means comprises: a) means for producing amplified linear analog signals in response to said proportional individual signals; and b) an analog-to-digital converter for converting said amplified linear analog signals into corresponding stepping digital signals.
Claim 11
Dependent Claim
66 words
A densitometer in accordance with claim 10, wherein said second processing signal means comprises: a) means for storing said linearly stepping digital signals; and b) means for separating said corresponding stepping digital signals into said at least first and second component signals, wherein said first component signal is capable of identifying specularly reflected light and said second component signal is capable of identifying diffusely reflected light.
Claim 12
Dependent Claim
58 words
An electrophotographic printing machine having a developer unit, toner, photoconductor charging and discharging devices, means for establishing toner test patches on a photoconductor, and a densitometer having a light source reflecting light on to said photoconductor as said test patches move past said light source, said densitometer being in accordance with any one of claims 1 to 11.
Claim 13
Independent Claim
79 words
A method of measuring reflected light, including the steps of: a) receiving at least a portion of said reflected light, wherein said receiving step comprises the steps of providing a plurality of discrete photosites arranged in a matrix array, and developing an individual signal at each photosite proportional to the amount of light received by each of said photosites; b) storing said signal generated by said receiving means; and c) actuating said storage means to transmit said signal therefrom.
References Cited (Backward Citations)
No citation records indexed.
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