Control of light-emitting diodes and sensors
AssigneeHewlett-Packard Development Company, L.P.
InventorsJavier Gonzalez BRUNO, Marti Rius Rossell, Jordi Ferran Cases
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Abstract
A densitometer includes a plurality of light-emitting diodes (LEDs) and at least one sensor. The LEDs are activated one at a time in a sequential, repeatable order. Photonic energy from each LED is reflected off an entity and is incident upon the sensor(s). Circuitry samples or acquires signaling from the sensor(s) in accordance with the respective LED activations. Signaling from the densitometer can be used in controlling ink-jetting printers or other apparatus.
Claims19
An apparatus, comprising:
- a plurality of light-emitting diodes (LEDs);
- a sensor to detect photonic energy emitted from a presently activated one of the LEDs and reflected from a proximate surface, the sensor to provide signaling corresponding to the detection;
- and
- circuitry to activate the sensor, the circuitry to activate the LEDs one at time in a sequential order, the circuitry to sample signaling from the sensor during the respective activations of the LEDs,
- in which the circuitry to activate the sensor comprises circuitry to wait for a predetermined period of time to stabilize a signal before sampling from the sensor.
A method performed using electronic circuitry, the method comprising:
- activating a sensor;
- activating a plurality of light-emitting diodes (LEDs) one at a time in a repeating sequence;
- detecting photonic energy emitted from each of the LEDs and reflected from a proximate surface using the sensor;
- and
- sampling a signal from the sensor in accordance with the activation of each of the LEDs, each signal sample corresponding to a luminance value,
- in which activating the sensor comprises waiting for a predetermined period of time to stabilize a signal before sampling from the sensor and before activating a first one of the LEDs in the sequential order.
A printing system, comprising:
- a controller;
- a print engine to form images on sheet media by way of ink-jetting, the print engine controlled by the controller;
- an apparatus having plural different light-emitting diodes (LEDs) and a sensor, the apparatus to activate the LEDs one at a time in an order, the apparatus to provide signals in accordance with photonic energy originating from each LED and reflected from a printed sheet of the media onto the sensor, the controller to control the print engine in accordance with the signals,
- in which the apparatus waits for a predetermined period of time to stabilize a signal before sampling from the sensor.
Dependencies are inferred from the claim text.