An inkjet printing system includes: (a) an inkjet printhead having a rigid elongate manifold with first and second parallel ink supply channels extending along a length of the manifold between respective ink ports positioned at opposite ends thereof; and a plurality of printhead chips mounted to a lower surface of the manifold, the ink supply channels supplying ink to the printhead chips via ink outlets defined in the lower surface. One end of the manifold has a first ink inlet port for the first ink supply channel and an ink outlet port for the second ink supply channel. The other end of the manifold has a first ink outlet port for the first ink supply channel and a second ink inlet port for the second ink supply channel. An ink delivery system is configured to flow ink along the first and second channels in opposite directions.

An image forming apparatus includes a print head including heating elements for applying a thermal energy to an imaging material, an operation unit configured to operate the plurality of heating elements of the print head by using a first pulse for preheating the color developing layers and a second pulse for developing the colors of the color developing layers, and a generation unit configured to, in a case where a spatial frequency of the image to be recorded based on image data for forming an image on the imaging material is lower than a predetermined frequency, generate the first pulse so that a temperature to be applied to the imaging material by the first pulse is lower than a temperature to be applied to the imaging material in a case where the spatial frequency of the image data is equal to or higher than the predetermined frequency.

A liquid discharge head substrate, comprising a discharging element configured to discharge a liquid, a driver configured to drive the discharging element, a conductive protection film covering the discharging element via an insulating film, and a controller connected to the protection film and configured to output a control signal that sets the driver in an inactive state when a change of a voltage of the protection film or a change in a current that flows to the protection film is detected.

In order to keep possible local temperature differences in a liquid ejection head small to allow stable liquid ejection performance to be achieved, temperatures in a plurality of heating areas in a liquid ejection head are discretely controlled using heating elements and temperature detection elements.

An ink heating device comprising an ink container that includes an ink pack filled with ink, and a case housing the ink pack and having a first opening and a second opening, and a blower that sends warm air into the case through the first opening. The warm air is discharged through the second opening.

A liquid discharge apparatus includes a plurality of heads configured to discharge a liquid, a liquid supply manifold configured to distribute the liquid to the plurality of heads, and a temperature-controlled liquid supply manifold configured to supply a temperature-controlled liquid to the plurality of heads. The temperature-controlled liquid supply manifold is thermally coupled to the liquid supply manifold.

There is provided a liquid discharge apparatus including: a head having a nozzle surface and a nozzle opened in the nozzle surface; a cap configured to make contact with the nozzle surface at a covering position and configured to be separated away from the nozzle surface at a retreating position; a liquid channel configured to communicate an internal space of the cap and outside of the cap to each other; a lid member configured to make contact with the cap located at the retreating position so as to seal the internal space of the cap; and a heater which is positioned above the cap located at the retreating position. The lid member is positioned between the heater and the cap in an up-down direction in a state that the lid member seals the internal space of the cap.

An ink heating device comprising an ink container that includes an ink pack filled with ink, and a case housing the ink pack and having a first opening and a second opening, and a blower that sends warm air into the case through the first opening. The warm air is discharged through the second opening.

A temperature sensor detects temperature of ink to be supplied to a plurality of nozzles. When, upon receiving a print request, a detection temperature detected by the temperature sensor is lower than a reference temperature, a control portion executes a preliminary vibration control to cause an ink meniscus oscillation to occur in each of the nozzles by vibrating the piezoelectric elements, and after the detection temperature increases up to the reference temperature, executes an ink ejection control to cause the ink to be ejected from the nozzles by vibrating the piezoelectric elements in correspondence with an output target image of a print request. When, upon receiving the print request, the detection temperature is higher than the reference temperature, the control portion executes the ink ejection control without executing the preliminary vibration control.

An image forming apparatus includes a print head including heating elements for applying a thermal energy to an imaging material, an operation unit configured to operate the plurality of heating elements of the print head by using a first pulse for preheating the color developing layers and a second pulse for developing the colors of the color developing layers, and a generation unit configured to, in a case where a spatial frequency of the image to be recorded based on image data for forming an image on the imaging material is lower than a predetermined frequency, generate the first pulse so that a temperature to be applied to the imaging material by the first pulse is lower than a temperature to be applied to the imaging material in a case where the spatial frequency of the image data is equal to or higher than the predetermined frequency.