Abstract: A communicating hole, which communicates between a clearance space and the outside of a cover member, is formed in the cover member, and a seal cap is fitted to and retained in a distal-end opening of the communicating hole. The seal cap includes a cap main body having a ventilation through hole formed in an internal axial direction and an outer peripheral wall configured to engage with the communicating hole, a supporting portion fitted, from the outside, into a recessed groove formed in an outside end face of the cap main body, and a ventilation filter located on a bottom face of the recessed groove and retained and sandwiched between the cap main body and the supporting portion. Therefore, an internal pressure rise in the clearance space between the cover member and an electric motor can be effectively suppressed, and thus improved mountability and retainability can be obtained.

Abstract: A valve timing control device for an internal combustion engine includes: a driving rotation member, a driven rotation member, a speed reduction mechanism, a circumferential clearance of the each of the rolling member being formed within an angle range of 0.01° to 0.4° in a circumferential direction from a reference line extending from a rotation axis of the driving rotation member in a radial direction, in a space constituted by the eccentric rotation member, the internal teeth constituting section, and the one of the holding holes.

Abstract: A valve-timing control apparatus varies a relative phase between a cam shaft and a crankshaft by energizing an electric motor through a power-feeding brush provided to be in contact with a slip ring. The valve-timing control apparatus includes a retaining member slidably retaining the power-feeding brush; a connector provided in the retaining member and connected to a power source; a pigtail harness including one end portion connected with the power-feeding brush, and another end portion connected with a terminal of the connector through a fixing portion; and a guide portion provided in the retaining member and including an outer circumferential surface formed in an arc-shape. The pigtail harness bends along the outer circumferential surface of the guide portion. The another end portion extends substantially in a linear arrangement from the fixing portion to a bending portion at which the pigtail harness bends along the outer circumferential surface.

Abstract: A valve timing control device for an internal combustion engine includes: a driving rotation member, a driven rotation member, a speed reduction mechanism, a circumferential clearance of the each of the rolling member being formed within an angle range of 0.01° to 0.4° in a circumferential direction from a reference line extending from a rotation axis of the driving rotation member in a radial direction, in a space constituted by the eccentric rotation member, the internal teeth constituting section, and the one of the holding holes.

Abstract: A valve-timing control apparatus varies a relative phase between a cam shaft and a crankshaft by energizing an electric motor through a power-feeding brush provided to be in contact with a slip ring. The valve-timing control apparatus includes a retaining member slidably retaining the power-feeding brush; a connector provided in the retaining member and connected to a power source; a pigtail harness including one end portion connected with the power-feeding brush, and another end portion connected with a terminal of the connector through a fixing portion; and a guide portion provided in the retaining member and including an outer circumferential surface formed in an arc-shape. The pigtail harness bends along the outer circumferential surface of the guide portion. The another end portion extends substantially in a linear arrangement from the fixing portion to a bending portion at which the pigtail harness bends along the outer circumferential surface.

Abstract: A variable valve operating apparatus including an electric motor including a motor housing with a permanent magnet, and a speed reducing mechanism having a casing, the motor housing and the casing of the speed reducing mechanism being coupled to each other by a plurality of bolts, wherein the motor housing includes a convex portion formed in a portion of the motor housing which is opposed to one axial end of the permanent magnet, the convex portion having a threaded hole into which a tip end portion of each bolt is screwed, and a projection formed on an axial end surface of the convex portion in alignment with the threaded hole in an axial direction of the threaded hole, and wherein the axial end surface of the convex portion is located further spaced from the one axial end of the permanent magnet than the projection.

Abstract: A variable valve operating apparatus including an electric motor including a motor housing with a permanent magnet, and a speed reducing mechanism having a casing, the motor housing and the casing of the speed reducing mechanism being coupled to each other by a plurality of bolts, wherein the motor housing includes a convex portion formed in a portion of the motor housing which is opposed to one axial end of the permanent magnet, the convex portion having a threaded hole into which a tip end portion of each bolt is screwed, and a projection formed on an axial end surface of the convex portion in alignment with the threaded hole in an axial direction of the threaded hole, and wherein the axial end surface of the convex portion is located further spaced from the one axial end of the permanent magnet than the projection.

Abstract: A manufacturing method of nozzle plate for liquid ejection head includes, providing a substrate having a first base material of Si and a second base material, of which the etching rate in Si anisotropic dry etching is lower then that of Si, provided on one side of the first base material, forming a film as a second etching mask on the surface of the second base material, forming a second etching mask pattern having a small-diameter opening shape in the second etching mask film, etching until the etching part is extended through the second base material, forming a film as a first etching mask film on the surface of the first base material, forming a first etching mask pattern having a large-diameter opening shape in the first etching mask film, and Si anisotropic dry etching until the etched part is extended through the first base material.

Abstract: Provided is a method for manufacturing a nozzle plate which has a through hole having an ejection port. In the method, the through hole, which has one opening as an ejection port for ejecting the liquid, is arranged on a Si substrate by an anisotropic etching method wherein etching and side wall protection film formation are alternately repeated to the Si substrate and the following steps are performed in the following order; forming a film to be an etching mask on a surface of the Si substrate whereupon the ejection port is to be formed, forming the etching mask pattern having an opening for forming the thorough hole by performing photolithography and etching to a film to be the etching mask, and performing the etching by the anisotropic etching method by satisfying the conditional expression.

Abstract: Provided is a method for manufacturing a nozzle plate which has a through hole having an ejection port. In the method, the through hole, which has one opening as an ejection port for ejecting the liquid, is arranged on a Si substrate by an anisotropic etching method wherein etching and side wall protection film formation are alternately repeated to the Si substrate and the following steps are performed in the following order; forming a film to be an etching mask on a surface of the Si substrate whereupon the ejection port is to be formed, forming the etching mask pattern having an opening for forming the thorough hole by performing photolithography and etching to a film to be the etching mask, and performing the etching by the anisotropic etching method by satisfying the conditional expression.

Abstract: Liquid ejecting apparatus 20 for ejecting electrically charged droplets of the liquid solution onto base member K, which includes liquid ejecting head 26 to eject the droplets from top end 21a of nozzle 21, with the inner diameter equal to or less than 100 ?m, liquid solution supplying section 29 to supply the liquid solution into nozzle 21, and ejection voltage applying section 25 to apply the ejection voltage onto the liquid solution in nozzle 21. In liquid ejecting apparatus 20, nozzle 21 projects toward the droplet ejecting direction from nozzle plane 26e on nozzle plate 26c facing base member K, whereby the projecting length of nozzle 21 is equal to or less than 30 ?m.

Abstract: A manufacturing method of nozzle plate for liquid ejection head includes, providing a substrate having a first base material of Si and a second base material, of which the etching rate in Si anisotropic dry etching is lower then that of Si, provided on one side of the first base material, forming a film as a second etching mask on the surface of the second base material, forming a second etching mask pattern having a small-diameter opening shape in the second etching mask film, etching until the etching part is extended through the second base material, forming a film as a first etching mask film on the surface of the first base material, forming a first etching mask pattern having a large-diameter opening shape in the first etching mask film, and Si anisotropic dry etching until the etched part is extended through the first base material.

Abstract: Liquid ejecting apparatus 20 for ejecting electrically charged droplets of the liquid solution onto base member K, which includes liquid ejecting head 26 to eject the droplets from top end 21a of nozzle 21, with the inner diameter equal to or less than 100 ?m, liquid solution supplying section 29 to supply the liquid solution into nozzle 21, and ejection voltage applying section 25 to apply the ejection voltage onto the liquid solution in nozzle 21. In liquid ejecting apparatus 20, nozzle 21 projects toward the droplet ejecting direction from nozzle plane 26e on nozzle plate 26c facing base member K, whereby the projecting length of nozzle 21 is equal to or less than 30 ?m.

Abstract: A light shutter device including a group of light shutter elements 31a, 31b 31c and 31d formed on a light shutter chip 30 made of PLZT has a construction in which an electrode gap is set wider in a element in which an electric field acts more strongly to equalize half wavelength voltages of elements almost to the same level since electric fields acting on the elements are different in strength from each other even under a prescribed voltage applied between a common electrode 32 and each of individual electrodes 33. An electrode gap of an element 31c having a weaker electric field is comparatively set narrower, whereas an electrode gap of an element 31d having a stronger electric field is set comparatively wider. Moreover, a shape of electrodes of each element are altered so as to make half wavelength voltages of elements almost equal.

Abstract: In order to attain a light shutter device capable of individually suppressing variations in quantity of transmitted light among light shutter elements regardless of differences in position of a light shutter element and pattern of electrodes around a light shutter element on a substrate, a light shutter device including a group of light shutter elements 31a, 31b, 31c and 31d formed on a light shutter chip 30 made of PLZT has a construction in which an electrode gap is set wider in a element in which an electric field acts more strongly to equalize half wavelength voltages of elements almost to the same level since electric fields acting on the elements are different in strength from each other even under a prescribed voltage applied between a common electrode 32 and each of individual electrodes 33.

Abstract: A light shutter device which has a plurality of light transmitting portions (light shutter elements) on a planar PLZT substrate. By applying voltages between a common electrode and individual electrodes to apply electric fields to the light shutter elements, the light shutter elements transmit and shut light individually. Suppose each of the individual electrodes faces the common electrode at a distance L and has a dimension W in a direction perpendicular to the direction of electric field, W/L>2. Suppose each of the individual electrodes has a dimension D in the direction of electric field, preferably D/L>0.5. Further, the individual electrodes are so placed that the distance between a side of one light shutter element which extends in a direction perpendicular to the direction of electric field and each of the individual electrodes which drive the other light shutter elements is not less than 5L.

Abstract: A light shutter device which, on a planar PLZT substrate, has a plurality of light transmitting portions (light shutter elements) which are disposed in two groups separated by a common electrode, and individual electrodes provided for the respective elements. Adjacent light shutter elements in each of the groups are arranged in mutually different lines so as to inhibit crosstalk.

Abstract: Disclosed is an optical writing device comprising a plurality of writing light shutter elements and at least one of monitoring light shutter element. Both the writing and monitoring light shutter elements are driven by being alternatively impressed a forward electric field and a reverse electric field with a predetermined impression ratio of the forward and reverse electric fields during optical writing operation. After the optical writing operation, the monitoring light shutter element is driven by being impressed the forward electric field with varying the amount of the electric field, whereby a half-wavelength voltage of the monitoring light shutter element is determined. For the next optical writing operation, the impression ratio is updated based on the determined half-wavelength voltage.

Abstract: A light shutter device which has a plurality of light transmitting portions (light shutter elements) on a planar PLZT substrate. By applying voltages between a common electrode and individual electrodes to apply electric fields to the light shutter elements, the light shutter elements transmit and shut light individually. Suppose each of the individual electrodes faces the common electrode at a distance L and has a dimension W in a direction perpendicular to the direction of electric field, W/L>2. Suppose each of the individual electrodes has a dimension D in the direction of electric field, preferably D/L> 0.5. Further, the individual electrodes are so placed that the distance between a side of one light shutter element which extends in a direction perpendicular to the direction of electric field and each of the individual electrodes which drive the other light shutter elements is not less than 5L.

Abstract: Disclosed is a light shutter device comprising a plurality of optical element for modulating light passing therethrough. Each optical element is made of PLZT and the surface of a light modulating region of each optical element is coated with a thin film. The surface electrical resistance on the thin film is 10.sup.10 .OMEGA./sq or less.