Abstract: There is provided a liquid ejecting head including a flow channel member and a piezoelectric element. The flow channel member includes a flow channel including a nozzle and a pressure chamber connected to the nozzle. The piezoelectric element is fixed to the flow channel member that applies pressure to the liquid in the pressure chamber and causes droplets to be ejected from the nozzle. The natural frequency Fr of the flow channel is 120 kHz or higher. The diameter D [?m] of the nozzle and the taper angle ? [° ] of the nozzle satisfy the relationships: ??2.1×D?36.4, D>22 ?m, and ?<45°.

Abstract: There is provided a liquid droplet ejecting head including: a channel member having a plurality of individual channels and a first common channel communicating with an inlet port of each of the plurality of individual channels; and a piezoelectric element arranged on the channel member. Each of the plurality of individual channels includes a nozzle, a pressure chamber communicating with the nozzle and a first communicating channel having an end which is the inlet port and the other end which communicates with the pressure chamber. The piezoelectric element is configured to apply a pressure to a liquid inside the pressure chamber to cause a liquid droplet of the liquid to be ejected from the nozzle. A channel resistance R1 [N s/m5] of the first communicating channel satisfies a first relational expression: 3.48×1013?R1?6.98×1013.

Abstract: There is provided a liquid droplet ejecting head including: a channel member having a channel which includes a nozzle and a pressure chamber communicating with the nozzle; and a piezoelectric element arranged on the channel member and configured to apply a pressure to a liquid inside the pressure chamber to eject a liquid droplet of the liquid from the nozzle. A diameter D [?m] of the nozzle and a natural frequency Fr [kHz] of the channel satisfy Expressions 1 and 2 as follows: Expression 1: D??2.25×10?8×Fr4+2.11×10?5×Fr3?7.60×10?3×Fr2+1.32×Fr?62.9, Expression 2: D?0.050×Fr+8.5.

Abstract: A liquid discharge apparatus includes a channel member defining a nozzle and a pressure chamber in communication with the nozzle; an actuator which applies pressure to liquid in the pressure chamber, and a controller which applies a drive signal to the actuator. The drive signal includes a rectangular main pulse and a rectangular cancel pulse applied after the main pulse within one discharge period. The actuator is driven by the drive signal in a pull-and-push method to discharge the liquid from the nozzle. If f (kHz) refers to a drive frequency of the drive signal, if Tw (?sec) refers to a time length from a falling edge of the main pulse to a rising edge of the cancel pulse, and if Tc (?sec) refers to a pulse width of the cancel pulse, then the following expression holds: 50?f??11.3×(Tw+Tc)+120.

Abstract: There is provided a piezoelectric actuator including: first to fourth piezoelectric layers and first to fifth electrodes. A part, of the first piezoelectric layer, between the first and second electrodes constitutes a first active part. A part, of the second piezoelectric layer, between the second and third electrodes constitutes a second active part. A part, of the third piezoelectric layer, between the third and fourth electrodes constitutes a third active part. Parts, of the first to fourth piezoelectric layers, between the first and fifth electrodes constitute two fourth active parts. A length of the third electrode is longer than a length of the second electrode and a length of the fourth electrode. Parts, of the first and second piezoelectric layers, between the first and third electrodes constitute two non-active parts. Parts, of the third and fourth piezoelectric layers, between the third and fifth electrodes constitute two fifth active parts.

Abstract: A liquid droplet ejection head includes a channel member and a piezoelectric element. The channel member has a channel. The channel includes a nozzle and a pressure chamber communicating with the nozzle. The piezoelectric element is fixed to the channel member and applies a pressure to liquid in the pressure chamber. The channel has a natural frequency Fr of 200 kHz or more. The nozzle has a diameter D [?m] and a taper angle ? [°] that satisfy ???2.3×D+65 and ?>1.9×D.

Abstract: A method for disassembling a cryocooler including a housing including a lower opening, a lower cover that closes the lower opening, a scotch yoke shaft that is accommodated in the housing and extends out of the housing by penetrating the lower cover, and a scotch yoke guide that is removably provided in the housing and guides axial movement of the scotch yoke shaft includes removing the lower cover from the housing, and taking the scotch yoke guide out of the housing from the lower opening.

Abstract: A liquid droplet discharging head includes: a channel member having a channel including a nozzle and a pressure chamber communicating with the nozzle; and a piezoelectric element fixed to the channel member and configured to apply pressure to liquid inside the pressure chamber to discharge liquid droplets of the liquid from the nozzle. A natural frequency Fr of the channel is not less than 250 kHz; and a diameter D [?m] of the nozzle has a relationship of the following expression (1) with the natural frequency Fr [kHz]: 0.0446×Fr+7.5?0.0446×Fr+13.5 . . . (1).

Abstract: A liquid droplet ejecting device includes a channel member and an actuator. The channel member has a channel. The channel includes a nozzle and a pressure chamber communicating with the nozzle. The actuator is on the channel member and configured to apply a pressure to a liquid in the pressure chamber. A diameter of the nozzle and a natural frequency of the channel are parameters of the liquid droplet ejecting device to satisfy that (1) the actuator has a threshold drive frequency of 100 kHz or more, (2) the nozzle ejects a liquid droplet having a volume of 1.8 pl or more, and (3) the Ohnesorge number is 0.2 or more.

Abstract: There is provided a liquid discharge head, including: a first channel member including individual channel rows and first common channels that correspond to the respective individual channel rows; a second channel member including a second common channel provided in common to the first common channels; and a third channel member including at least parts of connection channels connected to the second common channel. One of the connection channels is connected to an end in a longitudinal direction of the second common channel. The liquid discharge head further comprises a communication opening disposed at any other part of the second common channel except the end in the longitudinal direction, the second common channel communicating with the outside through the communication opening.

Abstract: A liquid droplet discharging apparatus includes: a channel member having a channel including a nozzle and a pressure chamber communicating with the nozzle; and a piezoelectric element fixed to the channel member and configured to apply pressure to liquid inside the pressure chamber to discharge liquid droplets of the liquid from the nozzle. A natural frequency Fr of the liquid inside the channel is in a range of 120 kHz to 160 kHz, a recording resolution which is a resolution of an image to be recorded by the liquid droplets is not less than 1200 dpi; and a diameter D [?m] of the nozzle and the natural frequency Fr [KHz] satisfy: D?0.0343×Fr+6.6979.

Abstract: A liquid droplet discharging apparatus includes: a channel member which has a channel including a nozzle and a pressure chamber communicating with the nozzle; and a piezoelectric element fixed to the channel member and configured to apply pressure to liquid inside the pressure chamber to discharge liquid droplets of the liquid from the nozzle. A natural frequency Fr of the channel is not less than 140 kHz, a recording resolution which is a resolution of an image to be recorded by the liquid droplet is not more than 600 dpi, and a diameter D [?m] of the nozzle and the natural frequency Fr [kHz] satisfy: D?0.0412×Fr+16.38.

Abstract: A liquid discharge head is provided, including a channel unit and a piezoelectric actuator stacked on the channel unit. The channel includes a channel including a nozzle and a pressure chamber. The piezoelectric actuator includes a piezoelectric element which includes a piezoelectric layer; a constant electric potential electrode arranged between the piezoelectric layer and the channel unit; and a driving electrode arranged on a surface of the piezoelectric layer opposite to the constant electric potential electrode. A relational expression of 0.5107?+18.476<?<0.7326?+54.409 is fulfilled assuming that ? represents a length in a transverse direction orthogonal to both of one direction and a stacking direction of the pressure chamber and ? represents a length in the transverse direction of the driving electrode.

Abstract: A liquid discharge head includes a flow passage substrate which is formed with individual flow passages, the individual flow passages including nozzles and pressure chambers communicated with the nozzles respectively, the pressure chambers being open on a surface of the flow passage substrate; a sealing member which is adhered to the surface via an adhesive and which seals the pressure chambers; and an actuator substrate which has a piezoelectric layer adhered to a surface of the sealing member on a side opposite to the flow passage substrate via an adhesive and individual electrodes formed on a side opposite to the sealing member with respect to the piezoelectric layer. The sealing member is composed of a material different from a material of the piezoelectric layer; and the surface has an adhesion area to which the sealing member is adhered and a non-adhesion area to which the sealing member is not adhered.

Abstract: A liquid discharge head includes: a first pressure chamber group formed by pressure chambers arranged in a first direction; a second pressure chamber group formed by pressure chambers arranged in the first direction, and disposed side by side with the first pressure chamber group in a second direction; a first common channel extending in the first direction and communicating with the pressure chambers composing the first pressure chamber group; a second common channel extending in the first direction and communicating with the pressure chambers composing the second pressure chamber group; a first dummy pressure chamber disposed on one side in the first direction relative to the first pressure chamber group; and a second dummy pressure chamber disposed on the one side in the first direction relative to the second pressure chamber group.

Abstract: There is provided liquid discharge head including: channel substrate which has first surface; and actuator substrate having second surface. A trap chamber configured such that the adhesive is trapped in the trap chamber in a case that the first and second surfaces are adhered to each other, an inflow channel configured such that the adhesive flows into the inflow channel, and an atmosphere communicating channel are formed in the channel substrate. The trap chamber has first and second ends in first direction and first and second ends in second direction. End of the inflow channel is located at the first end in the first direction and the second end in the second direction of the trap chamber. End of the atmosphere communicating channel is located at the second end in the first direction and the first end in the second direction of the trap chamber.

Abstract: A liquid discharge head includes: nozzles aligned on a nozzle surface; a supply manifold configured that a liquid is supplied therein from the outside of the liquid discharge head; a return manifold which is arranged between the nozzle surface and the supply manifold in a first direction, which is configured that the liquid is flown out therefrom to the outside of the liquid discharge head, and which is provided with a return damper part; and individual flow channels each of which corresponds to one of the nozzles. Each of the individual flow channels has a return throttle channel communicating the corresponding nozzle with the return manifold and being arranged between the return manifold and the nozzle surface in the first direction. The return manifold has a compliance larger than a compliance of the supply manifold.

Abstract: There is provided a liquid discharging head including: a pressure chamber configured to apply a pressure to a liquid so as to discharge the liquid from a nozzle; a descender arranged to overlap, in a plan view, with the nozzle and communicating the pressure chamber and the nozzle with each other; at least one return throttle channel connected to the descender; and a return manifold which communicates with the at least one return throttle channel and which is configured to receive the liquid not having been discharged from the nozzle. A cross section of the descender orthogonal to a depth direction of the descender is a non-circular shape having a major axis and a minor axis. The at least one return throttle channel is connected to at least one of a first end side of the minor axis and a second end side of the minor axis.

Abstract: A liquid discharge head is provided, the liquid discharge head comprising a plurality of individual channels, a first manifold connected to the plurality of individual channels, a second manifold connected to the plurality of individual channels, and a bypass channel connecting the first manifold and the second manifold and being distinct from the individual channels. A flow channel resistance Rct brought about by the plurality of individual channels, a flow channel resistance Rbp of the bypass channel, a bending loss ?P provided when the liquid flows from the first manifold via the bypass channel to the second manifold, and a flow rate Q of the liquid flowing through the bypass channel fulfill a relationship of: 0.5<[Rct/(Rbp+(?P/Q))]<2.0.

Abstract: A liquid discharge head includes: a first pressure chamber group formed by pressure chambers arranged in a first direction; a second pressure chamber group formed by pressure chambers arranged in the first direction, and disposed side by side with the first pressure chamber group in a second direction; a first common channel extending in the first direction and communicating with the pressure chambers composing the first pressure chamber group; a second common channel extending in the first direction and communicating with the pressure chambers composing the second pressure chamber group; a first dummy pressure chamber disposed on one side in the first direction relative to the first pressure chamber group; and a second dummy pressure chamber disposed on the one side in the first direction relative to the second pressure chamber group.