In one example in accordance with the present disclosure, a printing fluid container for a printing system is described. The printing fluid container includes a container body for holding printing fluid, a collar connected to the container body, and a cap removably engaging the collar. The collar has a plurality of collar teeth extending peripherally around the collar. The cap has a plurality of cap teeth extending peripherally around the cap. The cap teeth are configured for interfitment with the collar teeth such that rotation of the cap about the longitudinal axis in a first rotational direction effects cam-actuated removal of the cap from the collar.

In one example in accordance with the present disclosure, a printing fluid container for a printing system is described. The printing fluid container includes a container body for holding printing fluid, a collar connected to the container body, and a cap removably engaging the collar. The collar has a plurality of collar teeth extending peripherally around the collar. The cap has a plurality of cap teeth extending peripherally around the cap. The cap teeth are configured for interfitment with the collar teeth such that rotation of the cap about the longitudinal axis in a first rotational direction effects cam-actuated removal of the cap from the collar.

A method to determine a quantity of a liquid in a container. In the method, a actuator is controlled to rotate a member in the container at a first speed. A measurement of electrical current drawn by the actuator at the first speed is received. A quantity of liquid in the container is determined through a look-up table and the measured electrical current.

Provided is an electromagnetic wave generator including: an electromagnetic wave generation section that generates an electromagnetic wave; a high-frequency voltage generation section that generates a voltage applied to the electromagnetic wave generation section; and a transmission line that electrically couples the electromagnetic wave generation section and the high-frequency voltage generation section to each other, in which the electromagnetic wave generation section includes a first electrode, a second electrode, a first conductor that electrically couples the first electrode and the transmission line to each other, and a second conductor that electrically couples the second electrode and the transmission line to each other, one of the first electrode or the second electrode is a reference potential electrode to which a reference potential is applied and the other is a high-frequency electrode to which a high-frequency voltage is applied, a minimum separation distance between the first electrode and the second electrode is 1/10 or less of a wavelength of an output electromagnetic wave, a minimum separation distance between the first conductor and the second conductor is 1/10 or less of a wavelength of an output electromagnetic wave, and the first conductor further includes a coil, and the coil is closer to the first electrode than the transmission line.

An example printing system for printing liquid ink has a developer device to transfer ink to an image plate of the printing system. The developer device has an ink inlet to receive ink from an ink reservoir of the printing system; a developer roller to transfer ink to the image plate, a motor to rotate the developer roller, and an ink sensor to detect arrival of ink at the developer device. The printing system is configured to start the motor in response to the ink sensor detecting arrival of ink at the developer device.

In example implementations, a storage apparatus is provided. The storage apparatus includes a sealed reservoir partially filled with a print agent. A float is partially submerged in the print agent. A weight is coupled to a submerged portion of the float. A vent is coupled to the float and an opening in the sealed reservoir. A valve is coupled to an unsubmerged portion of the float.

In example implementations, a storage apparatus is provided. The storage apparatus includes a sealed reservoir partially filled with a print agent. A float is partially submerged in the print agent. A weight is coupled to a submerged portion of the float. A vent is coupled to the float and an opening in the sealed reservoir. A valve is coupled to an unsubmerged portion of the float.

An example door lock includes a button with a first region and a second region. The button actuates among multiple positions upon being engaged. A first link member is aligned to the button to detect a state of engagement of a door to a consumables compartment of an electronic device. A sensor is aligned to the button and the first link member to receive a signal from a signal generator based on the state of engagement of the door. A second link member has a first end to align with the button, and a second end to engage the door. A transducer causes the first end to align with the button to disengage the second end from the door upon engagement of the button with the first end.

An example door lock includes a button with a first region and a second region. The button actuates among multiple positions upon being engaged. A first link member is aligned to the button to detect a state of engagement of a door to a consumables compartment of an electronic device. A sensor is aligned to the button and the first link member to receive a signal from a signal generator based on the state of engagement of the door. A second link member has a first end to align with the button, and a second end to engage the door. A transducer causes the first end to align with the button to disengage the second end from the door upon engagement of the button with the first end.

A roller arrangement for printing apparatus comprises a first roller. The first roller comprises a plurality of cells. Each of the plurality of cells receives an amount of a coating material. The roller arrangement further comprises an extractor to remove at least a portion of the coating material from a selected set of the plurality of the cells.