It is disclosed a printing agent container having ink an authenticity detection mechanisms comprising: a receptacle having a top wall a bottom wall opposing such top wall and a sidewall between such top wall and such bottom wall; an internal volume defined by such receptacle that contains a printing agent, and a vibration transducer on one of the side walls, wherein the container is to be mechanically coupled to a carriage so that the printing fluid is disposed on the bottom surface, being the vibration transducer to detect a vibration signal induced by the carriage and wherein the container comprises a communication channel to a controller being the controller to receive through the communication channel a container signature from the vibration transducer and to identify a container identification signal associated to the container signature.

Provided is a printer including an ink tank, a print head performing printing by using ink in the ink tank, a light source provided at the substrate and irradiating the ink tank with light from a side of the ink tank, a photoelectric conversion device provided at the substrate and detecting light incident from the ink tank in a period during which the light source emits light, and a processing unit detecting an amount of ink based on an output of the photoelectric conversion device.

Provided is a printer including an ink tank having a mark at a side surface of the ink tank, a print head performing printing by using ink in the ink tank, a photoelectric conversion device provided outside the side surface having the mark among side surfaces of the ink tank, and detecting light from the ink tank, and a processing unit determining a position of an interface of the ink based on an output of the photoelectric conversion device and detecting an amount of ink in the ink tank based on a position of the mark and the position of the interface.

In an example, a method comprises fabricating a first validation device for association with a first replaceable print apparatus component. The device may be to form part of circuitry arranged on the first replaceable print apparatus component, and may provide an associated electrically detectable characteristic which varies with the position of at least part of the first validation device. The electrically detectable characteristic may be measured and data indicative of the characteristic may be stored in a first memory. The first replaceable print apparatus component comprising the first device and the first memory may be assembled.

A liquid surface sensor includes a hollow member having a first opening end and a second opening end, and a sensor unit provided so as to close the first opening end of the hollow member. The sensor unit includes a vibration plate, and a piezoelectric element which is provided on the vibration plate and is formed by laminating a first electrode film, a piezoelectric film, and a second electrode film in a thickness direction of the vibration plate.

A liquid ejection apparatus includes a nozzle, a pressure chamber, a piezoelectric element, an output processing portion, and a determination processing portion. The nozzle ejects a liquid. The pressure chamber communicates with the nozzle and contains the liquid. The piezoelectric element changes a pressure in the pressure chamber in response to an input of a drive signal. The output processing portion causes the piezoelectric element to output a first electric signal corresponding to vibration generated in the pressure chamber in response to the input of the drive signal to the piezoelectric element. The determination processing portion determines whether or not the pressure chamber is in a filled state in which the pressure chamber is filled with the liquid, based on a frequency of the first electric signal output by the output processing portion.

A liquid detecting apparatus includes an ultrasonic sensor that transmits and receives an ultrasonic wave, and includes a piezoelectric layer which is formed of a thin film and an ultrasonic element which is provided with a first electrode and a second electrode to interpose the piezoelectric layer between the first electrode and the second electrode, on a diaphragm which is disposed on a substrate having a cavity, and a flow path that forms the same liquid level as a liquid level of a liquid which is stored in a container, in which an acoustic matching layer and a detection surface of a surface of a lens, which are disposed on a side of the ultrasonic sensor that transmits and receives the ultrasonic wave, are disposed to be in contact with the liquid within the flow path.

A liquid surface sensor includes a hollow member having a first opening end and a second opening end, and a sensor unit provided so as to close the first opening end of the hollow member. The sensor unit includes a vibration plate, and a piezoelectric element which is provided on the vibration plate and is formed by laminating a first electrode film, a piezoelectric film, and a second electrode film in a thickness direction of the vibration plate.

A liquid detecting apparatus includes an ultrasonic sensor that transmits and receives an ultrasonic wave, and includes a piezoelectric layer which is formed of a thin film and an ultrasonic element which is provided with a first electrode and a second electrode to interpose the piezoelectric layer between the first electrode and the second electrode, on a diaphragm which is disposed on a substrate having a cavity, and a flow path that forms the same liquid level as a liquid level of a liquid which is stored in a container, in which an acoustic matching layer and a detection surface of a surface of a lens, which are disposed on a side of the ultrasonic sensor that transmits and receives the ultrasonic wave, are disposed to be in contact with the liquid within the flow path.

A fluid level sensor is configured for identifying a fluid level in a small volume reservoir, such as a fluid reservoir in an ejector head. The reservoir includes a plurality of vertically arranged chambers. A plurality of piezoelectric transducers is distributed over the chambers in a one-to-one correspondence. At least one electrical conductor is electrically connected to each piezoelectric transducer in the plurality of piezoelectric transducers to enable each piezoelectric sensor to receive an electrical signal to a portion of a wall of the chamber to produce an acoustical wave in the chamber and to transmit an electrical signal from each piezoelectric transducer in response to a fluctuating pressure on each piezoelectric transducer produced by the acoustical wave in the chamber.