Ultrasonic method for monitoring inkjet cartridge levels
AssigneeHewlett-Packard Company
InventorsGeorge Barbehenn, Martin K. Mason
Life of this patent
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Abstract
The present invention relates generally to inkjet printing mechanisms, and more particularly to an ultrasonic method for monitoring the ink level in an ink reservoir for an ink jet cartridge. This ultrasonic method includes the steps of sending an ultrasonic signal towards the ink reservoir, and receiving a series of reflected ultrasonic signals from the reservoir. In a processing step, the series of received reflected ultrasonic signals are processed in order to determine the ink level in the reservoir.
Claims20
A method of monitoring the inklevel in an ink reservoir of a replaceable ink jet cartridge installed in a printing mechanism for reciprocating back and forth across a print media, comprising the steps of:
- (a) sending an ultrasonic signal towards the ink reservoir;
- (b) receiving a series of reflected ultrasonic signals from the reservoir;
- and
- (c) processing the series of received reflected ultrasonic signals in order to determine the ink level in the reservoir.
The method of claim i wherein:
- the said ultrasonic signal is sent towards the ink reservoir from a location beneath the reservoir so as to induce reflected ultrasonic signals at the interface of an ambient medium and a wall of the reservoir, the interface of the wall of the reservoir and the ink contained in a cavity of the reservoir, and the surface level of the ink in the reservoir;
- and
- the ink level is determined as a function of the time at which each of the reflected ultrasonic signals is received.
A method of monitoring the ink level in an ink jet cartridge installed in an inkjet printing mechanism having an ultrasonic transceiver, comprising the steps of:
- (a) causing a relative movement of the inkjet cartridge and the ultrasonic transceiver so that the ultrasonic transceiver is located beneath the reservoir of the inkjet cartridge;
- (b) sending an ultrasonic signal from the transceiver towards the ink reservoir;
- (c) receiving a series of reflected ultrasonic signals from the reservoir at the transceiver;
- and
- (d) processing said series of received reflected ultrasonic signals in order to determine the ink level in the reservoir.
An ink jet printing mechanism for printing with an ink jet cartridge having one or more ink reservoirs, said ink jet printing mechanism comprising:
- carriage means for moving said ink jet cartridge across a print media;
- a sender for sending an ultrasonic signal towards said one or more ink reservoirs;
- a receiver for receiving a series of reflected ultrasonic signals from said one or more ink reservoirs;
- and
- a processing unit responsive to said series of reflected ultrasonic signals to determine the ink level in each of the reservoirs from the times at which the reflected ultrasonic signals in said series of reflected ultrasonic signals are received.
Dependencies are inferred from the claim text.