摘要:
A light radiated from a light source is focused on an optical disc by a focusing lens. A light reflected from the optical disc is introduced to a signal detection system. In the signal detection system, the introduced light is diffracted by a birefringent diffraction grating element utilizing an optical crystal. The diffracted light is received by a photodetector. Consequently, focus and track errors are detected, and information stored in the optical disc is re-produced.
摘要:
An optical head includes a reflection type grating lens for dividing specified polarized lights into a reflected light and a diffracted light, a device for detecting a RF signal from the reflected light of the grating lens, and a device for detecting focusing and tracking error signals from the diffracted light of the grating lens. The grating lens consists of a plurality of domains having different optical properties respectively, so that the reflected and diffracted lights are obtained. The optical head further includes a total reflection prism to compensate a phase difference between polarized lights orthogonal to a grating groove of the grating lens and parallel thereto, and a polarizing prism for dividing the reflected light into two polarized lights orthogonal to each other in polarization thereof. Thus, a simple, miniaturized, and inexpensive optical head is obtained.
摘要:
For use in combination with an optical source for generating a coherent beam along a main optical axis, an optical head device comprises a diffraction grating having a plurality of grating regions which are responsive to the coherent beam for directing a zeroth-order diffracted beam to a focussing lens and are responsive to an optical beaem reflected from an optical recording medium for directing sidewards diffracted beams to an optical detector assembly. An effective area of a diameter of about 5 mm is sufficient for the diffraction grating. Each sidewards diffracted beam may form an angle of 20.degree. with the main optical axis. The optical detector assembly is used in detecting focussing and tracking errors for the recording medium and can be used in reproducing optical information from the recording medium. A six-partitioned optical detector assembly is preferred when the grating regions are four in number. Either a four-partitioned or a three-partitioned optical detector assembly is preferred when the grating regions are two in number. Depending on the grating regions, the optical detector assembly preferably has two optical detector elements which are placed on different levels relative to the diffraction grating.
摘要:
An epoxy resin composition comprising (A) a naphthalene type epoxy resin in which 35-85 parts by weight of 1,1-bis(2-glycidyloxy-1-naphthyl)alkane and 1-35 parts by weight of 1,1-bis(2,7-diglycidyloxy-1-naphthyl)alkane are included per 100 parts by weight of the resin, (B) a phenolic resin curing agent, (C) a copolymer obtained through addition reaction of alkenyl groups on an alkenyl-containing epoxy compound and SiH groups on an organohydrogenpolysiloxane of 20 to 50 silicon atoms, and (D) an inorganic filler is best suited for semiconductor encapsulation because the cured composition has good thermal cycling, anti-warping, reflow resistance, and moisture-proof reliability.
摘要:
An epoxy resin composition comprising (A) a polyfunctional epoxy resin, (B) a phenolic resin, (C) an inorganic filler, and (D) curing catalyst-containing microcapsules having a mean particle size of 0.5-50 &mgr;m is suited for semiconductor package encapsulation since it minimizes the warpage of packages and has satisfactory catalyst latency, storage stability and cure.
摘要:
Process for the protection of a building that has already been built or is going to be built, whereby an effective amount of an insecticidally active compound is spread around or under the said building at discrete locations. The insecticide may be an arylpyrazole.
摘要:
A sheet heating device for heating a developer sheet to fix an output image formed thereon. The sheet heating device includes a guide plate and a cover member to define an internal space therebetween. Within the space, a heater and a fan is provided. The fan generate circulating hot air stream which is directed in a traveling direction of the developer sheet. The hot air has a transversal width substantially the same as a transverse length of the developer sheet.
摘要:
A method and apparatus for detecting a track and focus errors in an optical head comprises a step of dividing light beam which is reflected from a recording medium into at least a first, second, and third light beams belonging to first, second and third cross sectional regions thereof, and means therefor. The first region is expressed in its cross sectional position by the equations, ##EQU1## the second region is expressed in its cross sectional position by the equations, ##EQU2## the third region is excluded from said first and second regions and expressed in its cross sectional position by the equations, ##EQU3## where P is a pitch of pits or pregrooves of the recording medium, .lambda. is a wavelength of the light beam, .delta. is a value which is from equal to or more than zero to equal to or less than a maximum moving distance of the object lens in a direction of a track error, d is a diameter of the light beam which is reflected, X is an axis which is parallel to a track error direction to intersect the light axis of said light beam which is reflected, and Y is an axis which is orthogonal to the X to intersect said light axis. The track error is detected in accordance with the light beams of the first and second regions, and the focus error is detected in accordance with the light beam of the third region.
摘要:
A tag label producing apparatus has a cartridge holder for setting a first roll configured by winding a base tape equipped with identification marks, which include marks formed by two black strips and arranged with a pitch 2Pp and marks formed by one black strip and arranged with the pitch 2Pp, at a plurality of portions, a feeding roller driving shaft that feeds the base tape supplied from the first roll attached to the cartridge holder a print head that makes a predetermined print on the base tape or a cover film to be bonded thereto, and a mark sensor that detects the identification mark on the base tape, and controls the feeding roller driving shaft and the print head in coordination with each other in accordance with the detection result of the identification mark by the mark sensor.
摘要:
A support roller disposed on a side of a case main body of a facsimile apparatus is supported by a pair of right and left end holding members with associated coil springs for urging the support roller upward in an elevatable and oscillatable manner. A nose portion of a curl eliminating plate fixed to the lower surface of an upper cover member, which may be opened and closed, is disposed close to the circumferential surface of the support roller when the upper cover member is closed. When the upper cover member is closed, the support roller is inhibited from moving in either direction with respect to a feed path by restricting members projected downward from the upper cover member. The combination of the support roller and the nose portion of a curl eliminating plate define an S-shaped path through which the paper is fed to eliminate curl.