Ricoh Company, Ltd.

Kohta Akiyama

Noriyasu Takeuchi

Hiroshi Gotou

Akiko Bannai

Hidetoshi Fujii

Takashi Tamai

Ryuji Tsukamoto

Yuuki Mizutani

Kiminori Masuda

Naoko Kitaoka

Sumiaki Aoki

Ryohta Matsufuji

Chikako Hatta

Shinichiroh Osanai

Masaya Shingyoh

Ayumi Kuronuma

Akihiro Shima

A liquid discharge head includes: a diaphragm having a nozzle; a substrate including a pressure chamber communicating with the nozzle; a piezoelectric body over the diaphragm, the piezoelectric body configured to deform at least a part of an edge of the nozzle; and a vibration absorbing portion in the diaphragm.

Liquid discharge head, liquid discharge device, and liquid discharge apparatus

A liquid discharge head includes: a nozzle plate having multiple nozzle holes from which a liquid is to be discharged in a liquid discharge direction, the multiple nozzle holes arrayed in a nozzle array direction orthogonal to the liquid discharge direction; and a pressure chamber communicating with the multiple nozzle holes, wherein a volume Vof a virtual hemisphere Sis 5×10μmor more and 5×10μmor less, and a volume Vof a virtual hemisphere Sis five times or more and less than 1000 times the volume V, each of the multiple nozzle holes has a virtual center line, and the nozzle plate has an inner surface defining a wall of the pressure chamber, the inner surface having multiple openings of each of the multiple nozzle holes.

Liquid discharge head and liquid discharge apparatus

A liquid discharge apparatus is configure to drive nozzles with drive waveforms with which timing of discharge pulses fall within a range where a condition |A&#x2212;C|&#x3c;|B&#x2212;D| is satisfied, where 'A' is a discharge velocity of a droplet having a first size when drive units are driven to discharge a droplet having the first size, 'B' is a discharge velocity of a droplet having a second size larger than the first size when drive units are driven to discharge a droplet having the second size, &#x201c;C&#x201d; is a discharge velocity of a droplet having the first size when drive units are driven to discharge droplets having the first size and the second size, and &#x201c;D&#x201d; is a discharge velocity of a droplet having the second size when drive units are driven to discharge droplets having the second size and the first size.

Liquid discharge apparatus, image forming apparatus, and drive waveform generation method

A liquid discharge device and a method of discharging liquid. The liquid discharge device includes a head driver to drive an actuator element to generate force to discharge an ink droplet from a head onto an object to be conveyed, the object to be conveyed moving relative to the head, and a discharge controller. The discharge controller and the method includes computing a first drive cycle according to an amount of relative movement of the object moving relative to a head, adjusting the first drive cycle to a value within a second cycle range different from a first cycle range in which an ink droplet is abnormally discharged from the head, obtaining a second drive cycle as a result of adjustment performed on the first drive cycle, every time the second drive cycle passes one or more times, and adjusting the first drive cycle.

Liquid discharge device and liquid discharging method

A liquid discharge head includes a plurality of nozzles from which a liquid is discharged in a discharge direction, a plurality of individual chambers communicating with the plurality of nozzles, respectively, a common chamber communicating with each of the plurality of individual chambers, a drive element configured to change a volume of each of the plurality of individual chambers to discharge the liquid in the plurality of individual chambers from the plurality of nozzles, and a refrigerant channel through which a refrigerant flows, the refrigerant channel facing the common chamber via a partition in the discharge direction.

A liquid discharge head includes a plurality of individual chambers communicating with a plurality of nozzles that discharges a liquid, a common chamber formed by a frame and communicating with the plurality of individual chambers, a temperature detector to detect temperature of the liquid, and a temperature controller connected to the temperature detector, to heat or cool the liquid in the common chamber based on readings from the temperature detector. The temperature detector is disposed opposite the common chamber across the plurality of individual chambers in a direction perpendicular to a direction of liquid discharge from the plurality of nozzles.

A drive waveform generating device includes a plurality of waveform generating units each configured to generate and output a drive waveform to a corresponding one of a plurality of pressure generators that are provided corresponding to a plurality of nozzles of a liquid discharge head. Each of the plurality of waveform generating units includes a detector and a waveform generator. The detector is configured to detect data associated with a type of the drive waveform to be applied to at least one pressure generator of the plurality of pressure generators corresponding to at least one adjacent nozzle to a target nozzle. The waveform generator is configured to change a waveform shape of the drive waveform to be applied to one pressure generator of the plurality of pressure generators corresponding to the target nozzle in accordance with the data detected by the detector.

Drive waveform generating device, liquid discharge device, and liquid discharge apparatus

An inkjet recording method performed by inkjet recording device including nozzle plate with nozzle to eject droplets of ink; recording head including liquid chamber with which the nozzle is in communication, and pressure-generating unit configured to generate pressure in the liquid chamber; and signal-generating unit configured to generate signal applied to the pressure-generating unit, and allowing the droplets of the ink to eject by the pressure generated by the pressure-generating unit according to the signal, wherein the ink has static surface tension of 18.0 mN/m to 27.0 mN/m at 25&#xb0; C., the ink has receding contact angle on the nozzle plate of less than 50&#xb0;, the signal has two-step pull pulse for pulling the ink into the nozzle in two-step manner within one printing unit cycle, and the method includes pulling the ink located in proximity to nozzle outlet into the nozzle of the two-step pull pulse, to form meniscus at predetermined position.

Inkjet recording method and inkjet recording device

An image forming apparatus includes: and a unit that electrically shuts off a pressure generating unit corresponding to a nozzle ejecting no droplet, from a drive waveform generating unit for a period of a time Tb satisfying a relation Tb&#x2267;T, and that applies, at a time after the shutoff, a voltage of a potential Vto the pressure generating unit, where a potential serving as a reference for the drive waveform is denoted as V, a minimum potential difference from the potential Vrequired to displace a pressure generating unit to vibrate a meniscus with ejecting no liquid droplet from a nozzle is denoted as &#x394;V, a time required for a potential to drop by the potential difference &#x394;Vdue to self-discharge after a pressure generating unit is charged to a predetermined potential is denoted as T

Image forming apparatus

An inkjet recording method includes using ink for inkjet recording containing a hydrodispersible colorant, a surfactant, water, and an organic solvent containing a polyol, an amide compound represented by the following Formula I, and an oxetane compound represented by the following Formula II; using a recording medium having a particular transfer amount of highly deionized water as measured by an automatic scanning absorptometer; and forming an image on the recording medium with the ink, wherein the ink has a particular wettability, where &#x3b3;' represents dynamic surface tension as measured by maximum bubble pressure technique and &#x3b8; represents a contact angle,  

Inkjet recording method and inkjet printed matter

An image forming apparatus includes: a recording head including multiple nozzles and multiple piezoelectric elements that generate pressure for causing droplets to be ejected from the nozzles; a driving-waveform generating unit that generates a driving waveform to be applied to the piezoelectric elements; first switching devices each disposed between the driving-waveform generating unit and respective one of the piezoelectric elements; second switching devices each disposed between a predetermined voltage and respective one of the piezoelectric elements; and a slight-vibration control unit. The slight-vibration control unit causes slight vibrations to be applied to a non-ejection nozzle by placing the second switch device for the non-ejection nozzle in a conduction state, and, when a predetermined period of time has elapsed after shift to the conduction state, placing the second switch device in a non-conduction state and the first switch device for the non-ejection nozzle in a conduction state.

Growing community of inventors

Tokyo, Japan

Kohta Akiyama