A directionality detector is configured for use in an inkjet printer to attenuate the effects of ink drying in the nozzles of a printhead during printing operations. The directionality detector includes an optical sensor that generates image data of a test pattern formed on media by the printer, a diffuser that emits humidified air toward the media before the media is printed, and a controller operatively connected to the optical sensor and diffuser. The controller is configured compare the image data of the test pattern to stored image data of the test pattern printed at a previous time and determine whether any difference between the two images is greater than a predetermined threshold. The controller then operates the diffuser to direct humidified air toward the media passing the diffuser using the differences between the stored image data of the test pattern and the image data of the test pattern.

There is disclosed a housing including a plurality of compartments for housing a plurality of LEDs or photo detectors. Each compartment has a number of control pads projecting inwardly and a number of protrusions. The control pads are configured to provide a contact surface for the LEDs or photo detectors to control the alignment and position of each of the plurality of LEDs or photodiodes within each of the plurality of compartments. Each of the protrusions urges each of the plurality of LEDs or photodiodes against the respective control pads to control the alignment of the LEDs or photodiodes in the housing. A detector array including a casing, an LED housing and a photodiode housing is also disclosed.

There is disclosed a housing including a plurality of compartments for housing a plurality of LEDs or photo detectors. Each compartment has a number of control pads projecting inwardly and a number of protrusions. The control pads are configured to provide a contact surface for the LEDs or photo detectors to control the alignment and position of each of the plurality of LEDs or photodiodes within each of the plurality of compartments. Each of the protrusions urges each of the plurality of LEDs or photodiodes against the respective control pads to control the alignment of the LEDs or photodiodes in the housing. A detector array including a casing, an LED housing and a photodiode housing is also disclosed.

Example systems to determine print fluid ejection nozzle health for a printer device are disclosed along with corresponding methods. In an example, the system includes an image recording device to record an image of print fluid ejected from a print fluid ejection nozzle and disposed on a printable surface. In addition, the system includes an image processor to analyse the image to provide a result based on a characteristic of the image that are representative of the print fluid disposed on the printable surface. Further, the system includes a controller to receive the result and assign a nozzle health category to the print fluid ejection nozzle in dependence on the result.

A liquid ejecting apparatus includes a printing portion and a control portion. The printing portion executes a printing operation including ejecting a liquid from a nozzle onto a medium. The control portion executes an initial operation upon supply of power and executes the printing operation in accordance with a print instruction. The initial operation and the printing operation include a common printing operation that is common to the initial operation and the printing operation. When the control portion does not receive the print instruction during execution of the initial operation, the control portion executes the initial operation including the common printing operation. When the control portion receives the print instruction during execution of the initial operation, the control portion omits the common printing operation from the initial operation.

A liquid ejecting apparatus includes a printing portion and a control portion. The printing portion executes a printing operation including ejecting a liquid from a nozzle onto a medium. The control portion executes an initial operation upon supply of power and executes the printing operation in accordance with a print instruction. The initial operation and the printing operation include a common printing operation that is common to the initial operation and the printing operation. When the control portion does not receive the print instruction during execution of the initial operation, the control portion executes the initial operation including the common printing operation. When the control portion receives the print instruction during execution of the initial operation, the control portion omits the common printing operation from the initial operation.

The invention describes a number of methods and apparatus for shortening the inter-message gap on a continuous inkjet printer. Included is a novel phase testing methodology.

A fluid ejection die includes a plurality of actuation devices to eject fluid drops, at least one strain gauge sensor to sense strain, and a comparator. The comparator is to provide a fault signal in response to the sensed strain exceeding an impact threshold.

A fluid ejection die includes a plurality of actuation devices to eject fluid drops, at least one strain gauge sensor to sense strain, and a comparator. The comparator is to provide a fault signal in response to the sensed strain exceeding an impact threshold.

A fluid ejection system includes a fluid ejection die, a service station assembly, and a controller. The fluid ejection die includes at least one strain gauge sensor to sense strain. The service station assembly is to service the fluid ejection die. The controller is to receive the sensed strain from the at least one strain gauge sensor during servicing of the fluid ejection die and adjust or stop servicing of the fluid ejection die in response to the sensed strain exceeding a servicing threshold.