Abstract: An objective lens unit according to the present invention includes a first objective lens 41; and a first lens holder 2 for supporting the first objective lens 41. The first lens holder 2 is formed of a material which transmits ultraviolet. Preferably, the first lens holder 2 includes a through-hole, having first and second openings 2a and 2b, through which light incident on the first objective lens 41 passes, and an opening limiting section 3 provided along a circumferential direction of the through-hole and projecting toward a central axis of the through-hole. The first objective lens 41 is supported so as to block the first opening 2b. The opening limiting section 3 guides light incident thereon from the second opening 2a in a direction away from an optical axis of the first objective lens.

Abstract: An optical head for recording or reproducing a signal on or from an optical recording medium including a light source, an objective lens for condensing light emitted from the light source to the optical recording medium, and a light-separating device arranged between the light source and the objective lens in order to separate the light reflected from the optical recording medium from the light emitted from the light source. The light-separating device includes a first glass, a multilayer film formed on the first glass, and an adhesive layer arranged on the multilayer film in order to bond a second glass onto the multilayer film. The majority of the light emitted from the light source enters into the light-separating device through the first glass and is reflected by the multilayer film.

Abstract: An optical pickup device which can improve heat radiation efficiency and an optical disk apparatus including the optical pickup device are provided. The optical pickup device having a base (110), a laser unit (141), an optical system (140) which propagates a laser beam, and an adjusting member (142) includes a heat radiation part (146) which is fixed to a heat radiation surface (141b) of the laser unit and which conducts heat from the heat radiation surface to the adjusting member. Therefore, heat generated by the laser unit is transmitted to the adjusting member and then the base through the heat radiation part to make it possible to efficiently perform heat removal for the laser unit.

Abstract: An optical head for recording or reproducing a signal on or from an optical recording medium including a light source, an objective lens for condensing light emitted from the light source to the optical recording medium, and a light-separating device arranged between the light source and the objective lens in order to separate the light reflected from the optical recording medium from the light emitted from the light source. The light-separating device includes a first glass, a multilayer film formed on the first glass, and an adhesive layer arranged on the multilayer film in order to bond a second glass onto the multilayer film. The majority of the light emitted from the light source enters into the light-separating device through the first glass and is reflected by the multilayer film.

Abstract: In an optical beam transmissive adjusting mechanism (110) included in an optical pickup device, arrangement positions of a first transmissive element (111) having a first transmittance and a second transmissive element (112) having a second transmittance higher than the first transmittance are switched by a rotational drive unit (105), and an optical beam having a first optical power and an optical beam having a second optical power are output selectively. Furthermore, since a transmissive element of a non-transmissive side for an optical beam is arranged at an angle inclined to an optical axis of the optical beam, the transmissive element does not obstruct a path of the optical beam to be diffused.

Abstract: An optical head device 100 of the invention performs at least one of recording and reproducing of information for a plurality of types of optical recording mediums 7. A light source 1 emits a plurality of kinds of light having mutually different wavelengths. The positions for emitting the plurality of kinds of light from the light source are mutually deviated. A center C1 of first light 2a is matched with a pattern center C3 of a first diffracting plane 3a. A center C2 of second light 2b is matched with a pattern center C4 of a second diffracting plane 3b. The optical head apparatus 100 provided with the light source in which two or more light emitting elements are mounted in one module can perform stable tracking control.

Abstract: A small optical pickup of wide spherical aberration correction range includes a rising mirror for perpendicularly deflecting a light beam and guiding the light beam to an objective lens; a spherical aberration correction lens having one surface formed to a larger curvature than the other surface; a lens holder for holding the correction lens so that the surface of large curvature projects towards the rising mirror side; an axially extending guide member; and a slidable part slidable along the guide member. The projecting portion of the slidable part is configured to be fitted within the side surface of the reflecting surface of the rising mirror, and the projecting portion from the lens holder of the spherical aberration correction lens overlaps the reflecting surface of the rising mirror when the spherical aberration correction lens approaches the rising mirror the most.

Abstract: In an optical beam transmissive adjusting mechanism (110) included in an optical pickup device, arrangement positions of a first transmissive element (111) having a first transmittance and a second transmissive element (112) having a second transmittance higher than the first transmittance are switched by a rotational drive unit (105), and an optical beam having a first optical power and an optical beam having a second optical power are output selectively. Furthermore, since a transmissive element of a non-transmissive side for an optical beam is arranged at an angle inclined to an optical axis of the optical beam, the transmissive element does not obstruct a path of the optical beam to be diffused.

Abstract: An objective lens actuator is provided which includes two objective lenses mounted on a movable body, and which is capable of preventing the movable body from coming into contact or collision with a disk and whose thickness becomes thinner. When a light beam is concentrated and focused on a high-density optical disk, D1 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; when a light beam is concentrated and focused on a CD, D2 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; when a light beam is concentrated and focused on a DVD, D3 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; and the following relational expression (1) is satisfied, D1<D2<D3??(1).

Abstract: An optical head according to the present invention includes: a first light source that emits light with a first wavelength; a beam splitter that splits the light emitted from the first light source into a first light beam traveling in a first direction and a second light beam traveling in a second direction different from the first direction; a first collimator lens for changing degrees of divergence of the first light beam; a first mirror that changes the traveling directions of the first light beam, of which the degrees of divergence have been changed; a first objective lens for converging the first light beam, which has had its traveling directions changed, toward a storage layer of a first optical disk; a mover that holds the first objective lens; a first photodetector that receives the first light beam reflected from the storage layer of the first optical disk and converts it into an electrical signal; a condenser lens for condensing the second light beam; and a second photodetector that receives the sec

Abstract: A method of adjusting the tilt of objective lenses in an optical pickup having a plurality of light sources, an optical pickup component with a plurality of objective lenses which converge light from the plurality of light sources on an optical information recording medium and a movable part which holds the plurality of objective lenses, an actuator which drives the movable part of the optical pickup component, and a base on which the actuator is arranged and an optical system which introduces light emitted from the plurality of light sources to the plurality of objective lenses is constituted, which are capable of producing an optical pickup with a plurality of objective lenses while tilt is being simply adjusted, the method includes: a first tilt adjustment step of adjusting the tilt of the plurality of objective lenses with respect to the optical information recording medium with the optical pickup component temporarily arranged at a predetermined position on the base; and a tilt detecting step of detectin

Abstract: An objective lens unit according to the present invention includes a first objective lens 41; and a first lens holder 2 for supporting the first objective lens 41. The first lens holder 2 is formed of a material which transmits ultraviolet. Preferably, the first lens holder 2 includes a through-hole, having first and second openings 2a and 2b, through which light incident on the first objective lens 41 passes, and an opening limiting section 3 provided along a circumferential direction of the through-hole and projecting toward a central axis of the through-hole. The first objective lens 41 is supported so as to block the first opening 2b. The opening limiting section 3 guides light incident thereon from the second opening 2a in a direction away from an optical axis of the first objective lens.

Abstract: A lens surface of a collimating lens closer to a light source is in contact with a retracted surface at one end surface of a barrel. On a projecting surface at an outer side of the one end surface of the barrel, grooves are formed at a plurality of positions symmetric with respect to an optical axis. An adhesive deposited in the grooves is applied to an outer circumferential surface of the collimating lens to fix the collimating lens in the barrel. Since the grooves are formed to be shallower than the retracted surface, the adhesive does not intrude onto the retracted surface. The barrel is pressed against a wall surface formed in an inner circumferential surface of a barrel holder main portion and having a V-shaped cross section by a leaf spring, thereby being held at a specified position in the barrel holder main portion.

Abstract: A small optical pickup of wide spherical aberration correction range is provided.

Abstract: In an optical head device including a light source for emitting a light of a predetermined wavelength; a collimator lens for converting a divergence degree of the light; a folding mirror for folding a direction of the light emitted from the light source; an objective lens for converging the light on a recording surface of an optical disc; a photodetector for receiving the light reflected at the recording surface of the optical disc, and converting to an electric signal; and an optical path adjustment unit for guiding the light emitted from the light source to the collimator lens and guiding the light reflected at the recording surface of the optical disc to the photodetector; a wavelength plate for polarizing the light reflected by the folding mirror is arranged on an actuator base between the folding mirror and the objective lens.

Abstract: An optical pickup device which can more improve heat radiation efficiency and an optical disk apparatus including the optical pickup device are provided. The optical pickup device having a base (110), a laser unit (141), an optical system (140) which propagates a laser beam, and an adjusting member (142) includes a heat radiation part (146) which is fixed to a heat radiation surface (141b) of the laser unit and which conducts heat from the heat radiation surface to the adjusting member. Therefore, heat generated by the laser unit is transmitted to the adjusting member and then the base through the heat radiation part to make it possible to efficiently perform heat removal for the laser unit.

Abstract: An optical head device includes a focusing optical system for focusing a laser beam emitted from a semiconductor laser light source on an optical information medium with an objective lens. A chromatic aberration correction element for correcting chromatic aberration occurring in the objective lens is provided between the semiconductor laser light source and the optical information medium. A light distribution correction element in which the transmittance increases with the distance from the center of the aperture surface of the objective lens is provided so as to correct a reduction of the intensity of the light incident on the aperture surface of the objective lens with the distance from the center of the aperture surface.

Abstract: An optical head with excellent optical characteristics even when using a light source that substantially has a wavelength broadening is provided. The optical head includes a light source, an objective lens for focusing a light beam emitted from the light source on an information recording medium and a photodetector for detecting the light beam reflected from the information recording medium, wherein defocusing correction means and spherical aberration correction means are provided in an optical path between the light source and the information recording medium. Since both the defocusing correction means and the spherical aberration correction means are provided, while defocusing of a focused spot on the information recording medium caused by a wavelength broadening of the light source and chromatic aberration of the optical system can be corrected, the spherical aberration of the optical system caused by wavelength difference between a design wavelength and an incident wavelength also can be corrected.

Abstract: The present invention relates to an image forming apparatus that enables the occurrence of print defects due to a first print start time delay to be eliminated without using a temperature sensor that has a small thermal time constant. When the temperature of a fixing belt serving as an image heating body is greater than or equal to a predetermined temperature following the elapse of a fixed time after an image forming operation is started, recording paper is transported to a nip area (fixing area) of a fixing apparatus before the temperature detected by a temperature sensor reaches a predetermined image fixing temperature, and an image forming operation is started immediately.

Abstract: An image heating apparatus that enables a temperature of an image heating element to be stably maintained at a target temperature as a fixing speed varies. A Proportional-Integral-Derivative (PID) controller determines whether a temperature control computation results in a range that allows temperature control with one IGBT, and a linear control is performed if the result is at least equal to a minimum power obtained as IH output. PWM control is performed at minimum power if the power is less than a required minimum power. Thus, a computation method of a supply power computator need not be switched according to the fixing speed, and a calorific value of a fixing belt can be controlled using one computation method.