Imaging apparatus having media sensing system
First Claim
Patent Images
1. A detector for monitoring movement of imaging media along a transport path, the detector comprising:
- a light source positioned to transmit light across the transport path at a selected location;
a sensor positioned to receive light from the light source after the light crosses the transport path and configured to provide an output signal having a frequency based on an irradiance of the received light, wherein imaging media positioned at the at least one location affects the irradiance of the received light based on an optical density of the imaging media; and
a controller configured to measure the frequency of the output signal, to compare the measured frequency to a threshold frequency, and to provide a control signal indicative of the presence of imaging media at the selected location based on the comparison;
wherein the controller determines the threshold frequency based on a no-media frequency, wherein the no media frequency comprises a measured frequency of the output signal when imaging media is known not to be present at the selected location along the transport path; and
wherein the controller periodically adjusts the threshold frequency by periodically measuring the no-media frequency and determining an adjusted threshold frequency based on the measured no-media frequency.
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Abstract
A system for sensing imaging media along a transport path. System includes a light source positioned proximate to a selected location along transport path. A transducer in optical alignment with light source so as to receive light from light source after light crosses transport path provides an output signal having a frequency representative of the presence of imaging media at the selected location.
20 Citations
27 Claims
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1. A detector for monitoring movement of imaging media along a transport path, the detector comprising:
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a light source positioned to transmit light across the transport path at a selected location; a sensor positioned to receive light from the light source after the light crosses the transport path and configured to provide an output signal having a frequency based on an irradiance of the received light, wherein imaging media positioned at the at least one location affects the irradiance of the received light based on an optical density of the imaging media; and a controller configured to measure the frequency of the output signal, to compare the measured frequency to a threshold frequency, and to provide a control signal indicative of the presence of imaging media at the selected location based on the comparison; wherein the controller determines the threshold frequency based on a no-media frequency, wherein the no media frequency comprises a measured frequency of the output signal when imaging media is known not to be present at the selected location along the transport path; and wherein the controller periodically adjusts the threshold frequency by periodically measuring the no-media frequency and determining an adjusted threshold frequency based on the measured no-media frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for monitoring imaging media along a transport path, the system comprising:
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a plurality of detectors positioned along the transport path, wherein the plurality of detectors are spaced at intervals to form a linear array across a width of the transport path, each detector located at a different position in the linear array, each detector comprising; a light source transmitting light across the transport path at a selected location; a transducer receiving at least a portion of the light after the light crosses the transport path and providing an output signal having a frequency based on an intensity of the received light; and a controller configured to compare the frequency of the output signal to a threshold frequency and to provide a detector signal indicative of the presence of imaging media at the selected location based on the comparison; and a monitor configured to provide a control signal related to a characteristic of the imaging media based on the detector signal from each detector. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of monitoring the position of imaging media along a transport path, the method comprising:
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transmitting light across a selected location along the transport path; receiving at least a portion of the light after the light crosses the transport path; converting the received light to an output signal having a frequency indicative of the presence of imaging media at the selected location; measuring the frequency of the output signal; comparing the measured frequency to a threshold frequency; and providing a control signal indicative of whether imaging media is present at the selected location based on the comparison; and periodically updating the threshold frequency. - View Dependent Claims (22, 23, 24)
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25. A system for sensing imaging media along a transport path, the system comprising:
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means for transmitting light across a selected location along the transport path; means for receiving at least a portion of the light after the light crosses the transport path; means for converting the received light to an output signal having a frequency based on an intensity of the received light and indicative of the presence of imaging media at the selected location; means for measuring the frequency of the output signal; means for comparing the measured frequency to threshold frequency; and means for providing a control signal indicative of whether imaging media is present at the selected location based on the comparison; and means for periodically updating the threshold frequency. - View Dependent Claims (26, 27)
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Specification