Abstract: A first electrode of a liquid crystal cell (21) is composed of a plurality of concentric electrodes (31 to 34) of a concentrically circular shape, the plurality of concentric electrodes are divided into a first group of concentric electrodes (44) near the center and a second group of concentric electrodes (45) near the periphery, and a concentric electrode between the two groups is an independent single electrode (36). A first correction unit that corrects spherical aberration of a high density DVD is composed of the two groups and a second correction unit that corrects aberration of a conventional DVD is composed of the first group of concentric electrodes (44). In the case of correcting the aberration of the conventional DVD, the independent concentric electrode (36) is supplied with a voltage between the voltages respectively supplied to adjacent concentric electrodes (35), (37).

Abstract: A first electrode of a liquid crystal cell (21) is composed of a plurality of concentric electrodes (31 to 34) of a concentrically circular shape, the plurality of concentric electrodes are divided into a first group of concentric electrodes (44) near the center and a second group of concentric electrodes (45) near the periphery, and a concentric electrode between the two groups is an independent single electrode (36). A first correction unit that corrects spherical aberration of a high density DVD is composed of the two groups and a second correction unit that corrects aberration of a conventional DVD is composed of the first group of concentric electrodes (44). In the case of correcting the aberration of the conventional DVD, the independent concentric electrode (36) is supplied with a voltage between the voltages respectively supplied to adjacent concentric electrodes (35), (37).

Abstract: A piezoelectric actuator is deformed from an initial condition for a time (T1) in a direction, in which an inner volume of an ink chamber is increased, to supply ink to the ink chamber. Subsequently, the piezoelectric actuator is deformed for a time (T2) at a considerably slow speed as compared with the time (T1) for the preceding supply of ink to gradually increase the inner volume of the ink chamber to supply ink to the ink chamber. During the time (T2), free oscillation having generated in ink in the piezoelectric actuator and the ink chamber attenuates. Subsequently, the piezoelectric actuator is rapidly deformed to compress the ink chamber, thereby jetting ink in the ink chamber via nozzle holes.

Abstract: An ink-jet head comprises: an insulating base (10); a plurality of juxtaposed multilayer piezoelectric elements (20) each formed by alternately stacking conductive members and piezoelectric plates polarized in the direction of the thickness and having a lowermost layer (25) and an uppermost layer (26) which are nondriven layers which are not distorted even when voltage is applied thereto; an elastically bendable oscillation plate (30); and a flow passage plate (40) provided with a plurality of ink outlets(43) at the front end thereof, and a plurality of juxtaposed ink chambers (41) connected to the ink outlets (43). The lowermost layers (25) of the multilayer piezoelectric elements (20) are bonded to the upper surface of the base (10), and the oscillation plate (30) is bonded to the uppermost layers (26) of the multilayer piezoelectric elements (20).

Abstract: Pairs of laminated piezoelectric actuator (111) are arranged in plural rows on a base plate (110) to form a laminated piezoelectric actuator unit. A diaphragm (115) is bonded to the upper end surface of the laminated piezoelectric actuator unit, and a flow path plate (118) is bonded to the upper surface of the diaphragm (115). Here, a plurality of pressurizing chambers (116) and an ink flow path (117) are formed in the flow path plate (118) such that each pressurizing chamber (116) is disposed corresponding to each laminated piezoelectric actuator (111). Moreover, a nozzle plate (120) having nozzle holes (119) is connected to the upper surface of the flow path plate (118). Each laminated piezoelectric actuator (111) is deformed in the direction of thickness by applying voltage thereto for ejecting ink inside each pressurizing chamber (116) via each nozzle hole (119) in a direction perpendicular to the base plate (110).

Abstract: An ink-jet head comprises: an insulating base (10); a plurality of juxtaposed multilayer piezoelectric elements (20) each formed by alternately stacking conductive members and piezoelectric plates polarized in the direction of the thickness and having a lowermost layer (25) and an uppermost layer (26) which are nondriven layers which are not distorted even when voltage is applied thereto; an elastically bendable oscillation plate (30); and a flow passage plate (40) provided with a plurality of ink outlets(43) at the front end thereof, and a plurality of juxtaposed ink chambers (41) connected to the ink outlets (43). The lowermost layers (25) of the multilayer piezoelectric elements (20) are bonded to the upper surface of the base (10), and the oscillation plate (30) is bonded to the uppermost layers (26) of the multilayer piezoelectric elements (20).

Abstract: A heat pump apparatus comprising: a heat pump circuit composed of an external combustion engine, a radiator through which a first medium heated by a first heat exchanger of said external combustion engine flows and a cooler through which a second medium cooled by a second heat exchanger of said external combustion engine flows; a motor for supplementing a motive power to said external combustion engine; a brake for braking said external combustion engine; a detector for detecting a heating load; and a controller for calculating a motive power necessary for said external combustion engine based on the difference between a value detected by said detector and a preset value previously set, and for controlling said motor to move when the calculated motive power is larger than a self-output of said external combustion engine.