Abstract: A dichroic mirror is a wedge-shaped quadrangular prism whose cross-section is a trapezoid having an upper base d and a lower base d+?d. The dichroic mirror receives on its top surface parallel light emitted from a collimating lens and reflects, off the top surface, most of the parallel light towards a wavelength plate. Moreover, the dichroic mirror transmits, through the top surface, part of the parallel light to output the part of the parallel light from a bottom surface facing the top surface toward a front monitor. The dichroic mirror has, on the bottom surface thereof, an inclination of an angle ? with respect to the top surface in a direction where a normal vector N of the bottom surface intersects with an xy-plane formed of: an optical axis x of incident light from the collimating lens; and an optical axis y of light emitted towards the wavelength plate.

Abstract: An optical pickup lens for focusing a light beam from a laser light source on an optical information recording medium is a single lens. The optical pickup lens has two surfaces, and a surface R2 opposite to a surface R1 closer to the laser light source has a continuous shape. When the surface R2 has radii h1, h2 and h3 (h1<h2<h3) from an optical axis to a lens periphery, and where sags in the radii h1, h2 and h3 are sag1, sag2 and sag3, and differentials in the sags are ?sag1, ?sag2 and ?sag3, respectively, 0>?sag1>?sag2 and ?sag2<?sag3 are satisfied.

Abstract: There is provided a low-cost and reliable optical pickup device, wherein an objective lens is in contact with an adhesive at least one or more portions and fixed to the adhesive and also the height of the adhesive for fixing the objective lens is higher than the surface of the objective lens or the end of the objective lens, thereby a sufficient adhesive strength is secured between the objective lens and a member to which the objective lens is adhered and further this adhesive serves also as a disc protector.

Abstract: When recording/reproducing an optical disc having a recording layer of multi-layer structure, an unwanted optical beam reflected from a recording layer other than a target layer for recording/reproduction is incident on a photodetector to cause an unwanted disturbance component to leak to a detection signal, giving rise to a degradation in the quality of a tracking control signal. In an optical pickup apparatus, for suppression of the degradation, an optical element is mounted having a diffraction area for diffracting part of the optical beam and light receiving planes for sub-optical beams are provided each of which has a light shielding zone or dead zone of a predetermined width on its central sectioning line.

Abstract: An optical pickup includes: a light source that emits a light beam; an object lens that focuses the light beam on an optical disc having a recording layer formed of a fluorescent recording material and a reflecting section adjacent to the recording layer, the recording layer generating, according to presence or absence of a recording mark representing information, a reproduction light beam having wavelength different from that of the light beam when the light beam is irradiated thereon from the light beam, and the reflecting section reflecting the light beam; a wavelength selecting element that separates, from the reproduction light beam, a reflected light beam reflected by the reflecting section of the optical disc and having wavelength equivalent to that of the light beam; and a reflected light detector that receives the reflected light beam separated by the wavelength selecting element and generates a position detection signal.

Abstract: An optical element for use in an optical pickup device to conduct reproducing and/or recording information for a first disk including a protective substrate by the use of a first light flux emitted from a first light source and to conduct reproducing and/or recording information for a second disk including a protective substrate by the use of a second light flux emitted from a first light source, the optical element includes: an optical surface on which a first phase structure is formed to have a function to correct a spherical aberration; an optical surface on which a second phase structure is formed such that when the wavelength of the first light flux changes, the second phase structure generates a spherical aberration in a direction reverse to the direction of a spherical aberration generated by the first phase structure.

Abstract: In an optical pickup device 1 and a temperature characteristics correction method for an object lens, structure is employed in which a prescribed temperature recognition operation is performed on temperature information detected by a thermistor 16, temperature of the object lens 7 is recognized, temperature characteristics of the lens is corrected, and the structure includes a temperature recognition operation waiting function that the temperature recognition operation is held waiting for a predetermined time period L1 defined in advance, and the temperature recognition operation is started after the predetermined time period has elapsed, therefore, the optical pickup device and the temperature characteristics correction method do not generate insufficient correction or excessive correction and proper temperature characteristics correction is made possible when the temperature characteristics of the object lens is corrected by recognizing temperature of the object lens utilizing the thermistor arranged on a d

Abstract: A lens has a flange part at the outer periphery of its surface. A flange surface of the flange part is higher than the lens surface. The flange surface has a marking to identify a production jig, for example.

Abstract: The optical storage medium comprises a substrate layer, and a data layer having a mark/space data structure with data arranged in tracks on the substrate layer, wherein between neighboring tracks alternatingly a groove section or a land section without a groove is arranged. The tracks, groove sections and land sections may be arranged by providing a single spiral, two spirals, or four spirals on the optical storage medium. The optical storage medium is in particular an optical disc comprising a nonlinear layer with a super-resolution structure arranged above the data layer.

Abstract: An optical disc device includes: a first searching part which searches a condition where amplitude level of a TE signal is made maximum by changing either one of position of a movable lens and a focus balance value in a state where a focus servo control is performed based on a FE signal; an adjusting line setting part which sets an adjusting line that has an inclination ? which is preliminarily stored in a memory portion and that passes the position of the movable lens and the focus balance value both of which are searched by the first searching part; and a second searching part which changes the position of the movable lens and the focus balance value to plural values on the adjusting line in a state where the focus servo control is performed consecutively to search a condition where the amplitude level of the tracking error signal is made maximum.

Abstract: According to one embodiment, a write-once type information storage medium comprises an organic dye based recording material having sensitivity at a wavelength of 405 nm and at a recording wavelength in the range of 600 nm to 700 nm, wherein, when absorbance of a maximum absorption wavelength in the vicinity of 405 nm is defined as 1, the absorbance is 5% or more at any wavelength in the range of 600 nm to 700 nm.

Abstract: [Object] A recoding playback apparatus and an optical disk are provided that allows reduction of a low frequency noise at a time of playback of a super resolution optical disk including small record marks whose size is below the diffractive limitation, to enhance quality of a playback signal. [Means for Solution] The reflective beams from the optical disk are received by dividing into outer portion beams and a center portion beam, and a playback signal is created by combining such beams based on respective different gains. Based on received amounts of light or amounts of low frequency noise in respective light receiving regions, adjustment or determination of gain values is made, or the optical head apparatus is optically adjusted, whereby the low frequency noise is optimally suppressed. Further, a specific region is provided on the optical disk for making the foregoing adjustment.

Abstract: A recording and reproducing method for recording and/or reproducing information from a record carrier that comprises a plurality of recording layers layered in its film thickness direction and a guide layer having a plurality of tracks carrying tracking servo information, wherein a record mark is formed on each recording layer of the record carrier. The method comprises: a focusing step of converging a servo light beam onto the guide layer as well as selectively converging a main light beam group onto one of the recording layers through a common objective lens, wherein the main light beam group comprises a plurality of main light beams neighboring each other; a tracking step of performing a positioning control of the objective lens so that the servo light beam is tracking on one of the tracks; and a recording and/or reproducing step of performing recording and/or reproducing information with the main light beam group while performing the focusing step and the tracking step.

Abstract: An objective lens focusing light emitted from a light source onto an information surface of an optical disk, comprising: a first lens surface to be positioned on the light-source side; a second lens surface to be positioned on the optical-disc side; a first edge surface to be positioned on the light-source side, provided in an outer region of the first lens surface; and a second edge surface to be positioned on the optical-disc side, provided in an outer region of the second lens surface, a first optical axis of the first lens surface coinciding with a second optical axis of the second lens surface, the first optical axis and the second optical axis being orthogonal to the second edge surface.

Abstract: An objective lens apparatus is disclosed. The apparatus includes: a first objective lens with a first numerical aperture, which is capable of focusing a laser light on a first optical record medium with a first cover layer of a first thickness; a second objective lens with a second numerical aperture smaller than the first numerical aperture, which is capable of focusing the laser light on a second optical record medium with a second cover layer of a second thickness larger than the first thickness; a third objective lens with a third numerical aperture smaller than the second numerical aperture, which is capable of focusing the laser light on a third optical record medium with a third cover layer of a third thickness larger than the second thickness; and a lens holder which holds the first objective lens, the second objective lens, and the third objective lens.

Abstract: An object lens actuator can improve workability and operate with high reliability by prevention of damage to the object lens actuator and a disc and sticking of a moving part caused by an excessive movement of the moving part. In a disc drive employing the object lens actuation, stable writing/reading operation is implemented by always keeping a focal point of an object lens at a predetermined track of a recording surface of the disc even when being under the action of external perturbations such as a vertical deviation or a radial deviation of the disc, resulting in improved reliability. A solder-flux adhesion prevention gadget is provided between a substrate and a stopper receiving face, which may include a stepped stage, a partition protruding from the surface of the lens holder, or alternatively a combination of them arranged in order in the range.

Abstract: There is provided an objective lens including a first optical member and a second optical member which are made of materials different from each other and are cemented together at a cementing surface. The cementing surface includes a first phase shift structure having a plurality of refractive surface zones concentrically formed about an optical axis of the objective lens. The first phase shift structure satisfies conditions (1) and (2): 0.85<?2/?1<1.15??(1) 0.10<|(?3??2)/?1|<0.50??(2) where ?1=m(?1)×(?1/(n2(?1)?n1(?1))), ?2=m(?2)×(?2/(n2(?2)?n1(?2))), ?3=m(?3)×(?3/(n2(?3)?n1(?3))), m(?1), m(?2), and m(?3) are diffraction orders at which diffraction efficiencies of the first through third light beams are maximized, respectively, n1 (?1), n1 (?2), and n1 (?3) are refractive indexes of the first optical member, respectively, and n2 (?1), n2 (?2), and n2 (?3) are refractive indexes of the second optical member, respectively.

Abstract: A microprocessor performs preliminary tracking servo control of an objecting lens by moving the objective lens in a radial direction of an optical disc so as to allow a laser beam reflected by the optical disc to be equally divided and received by first and second light receiving sections PD1, PD2 of the photodiode PD before the microprocessor starts tracking servo control of the objective lens. This makes it possible to perform preliminary tracking servo control of the objective lens before tracking pull-in, and thereby to obtain an appropriate tracking error signal for performing stable tracking pull-in, even when an optical disc with an offset center of gravity is mounted on an optical disc apparatus.

Abstract: According to the present invention, provided is a disc device including a disc mounting unit having a mounting surface, on which a disc-like recording medium is mounted; a print head for discharging ink towards a label surface of the disc-like recording medium mounted on the disc mounting unit; and a mist inducing unit for inducing the ink discharged from the print head when applied with a predetermined voltage.

Abstract: An optical pickup apparatus according to the present invention includes: a first light source for emitting a first light flux; a second light source for emitting a second light flux; a third light source for emitting-a third light flux; and an objective optical element. The objective optical element has an optical surface including at least two areas provided with optical path difference providing structures. The objective optical element converges the first to third light fluxes each passing through the predetermined areas on the objective optical element onto respective information recording surfaces of the first to third optical disks. The optical pickup apparatus provides a wavelength dependency of a spherical aberration so as to correct a change in a spherical aberration due to a refractive index change with a temperature change of the objective optical element.

Abstract: An objective lens relating to the present invention includes a first optical path difference providing structure in which a first basic structure and a second basic structure are overlapped with each other. The first basic structure is a blaze-type structure which emits a Xth-order diffracted light flux, when the first light flux passes through the first basic structure, where the value of X is an odd integer. At least a part of the first basic structure arranged around an optical axis includes a step facing an opposite direction to the optical axis. The second basic structure is a blaze-type structure which emits a Lth-order diffracted light flux, when the first light flux passes through the second basic structure, where the value of L is an even integer. At least a part of the second basic structure arranged around the optical axis includes a step facing the optical axis.

Abstract: An objective lens driving device includes a lens holder (3) holding an objective lens (1, 2), a stationary part (5) that supports the lens holder (3) via wires (7a, 7b), an electromagnetic coil (11a-11d, 12a-12d) provided on the lens holder, and a magnet (4a, 4b) provided on the stationary part and magnetized in a multipolar manner so that different magnetic pole surfaces are arranged on a surface of the magnet facing the electromagnetic coil. The lens holder has a convex portion (16a-16d, 17a-17d) on a surface thereof facing the magnet. The convex portion has at least one groove (601-604, 701-704) portion extending parallel to a direction of magnetic flux lines of the magnet facing the convex portion, and at least a surface of the convex portion is formed of material having magnetic property.

Abstract: An optical pickup lens for focusing a light beam from a laser light source on an optical information recording medium is a single lens. The optical pickup lens has two surfaces, and a surface R2 opposite to a surface R1 closer to the laser light source has a continuous shape. When the surface R2 has radii h1, h2 and h3 (h1<h2<h3) from an optical axis to a lens periphery, and where sags in the radii h1, h2 and h3 are sag1, sag2 and sag3, and differentials in the sags are ?sag1, ?sag2 and ?sag3, respectively, 0>?sag1>?sag2 and ?sag2<?sag3 are satisfied.

Abstract: A method of performing writable optical recording of a medium to form multilevel oriented nano-structures therein, comprises steps of providing a disc-shaped, writable recording medium having a planar surface; and encoding data/information in the medium by forming a plurality of multilevel nano-structured pits in the surface by scanning with a focused spot of optical energy to form at least one data track therein, including scanning the optical spot in a cross-track direction while rotating the disc about a central axis.

Abstract: An optical system for optical pickup, which optical system is used for performing recording, reproducing, and/or erasing of information on an optical recording medium and has a simple configuration, is provided. An optical pickup device 1 includes a collimator lens system 23, a beam expander 33, and an objective lens system 34 that includes an S-SIL element 27b. The beam expander 33 includes a lens element 33c that is supported so as to be movable in a direction perpendicular to an optical axis. By moving the lens element 33c in the direction perpendicular to the optical axis, a coma aberration of a spot on a recording layer can be compensated in a state where the interval between a surface of an optical recording medium 28 and the S-SIL element 27b opposed thereto is maintained constant.

Abstract: An optical pickup device is provided. The optical pickup device includes a light source, a focusing optical system configured to irradiate an optical recording medium with near-field light, a light-detecting unit configured to detect a total-reflection return-light quantity from the optical recording medium, a control unit configured to generate a control signal in response to a detection signal supplied from the light-detecting unit, and a drive unit configured to drive the focusing optical system to a predetermined position above the optical recording medium. The control unit feeds forward a push-pull signal in a traveling direction of the drive unit relative to the optical recording medium to a gap-error signal supplied from the light-detecting unit to generate a gap-servo signal. The control unit includes a repetitive controller storing a predetermined number of the push-pull signals.

Abstract: An optical pickup device includes: a light source; a collimator lens for converting a light beam emitted from the light source into parallel light; an objective lens for converging the light beam to the optical disc; an extending portion in which a light flux transversal width as the width of the parallel direction with respect to the information recording face of the optical disc of the light beam converted into the parallel light by the collimator lens is extended until a final light flux diameter as the diameter of the light beam at an incident time to the objective lens; and a prism in which a light flux longitudinal width as the width of a direction perpendicular to the information recording face of the optical disc of the extended light beam is extended until the final light flux diameter, and the light beam is emitted to the objective lens.

Abstract: An optical pickup device includes: a light source that emits a light beam; a divergence-angle converting lens that converts an angle of divergence of the light beam emitted from the light source and emits the light beam; and an object lens displaceable in a tracking direction that receives incidence of the light beam, the angle of divergence of which is converted by the divergence-angle converting lens, and converges and emits the light beam, wherein spherical aberration equivalent to an amount that can offset astigmatism caused when the object lens is displaced is given to the divergence-angle converting leans, and spherical aberration that can offset the spherical aberration given to the divergence-angle converting leans is given to the object lens and comatic aberration that can offset comatic aberration caused by the spherical aberration given to the divergence-angle converting lens when the object lens is displaced is given to the object lens.

Abstract: An optical pickup device imparts different astigmatisms from each other to light fluxes in four light flux areas formed around an optical axis of laser light, out of the laser light reflected on a disc. The optical pickup device also changes the propagating directions of the light fluxes in the light flux areas to separate the light fluxes in the light flux areas each other. A signal light area where only signal light exists is defined on a detection surface of a photodetector. Eight sensing portions are arranged at a position corresponding to the signal light area. According to this arrangement, only the signal light is received by the sensing portions to thereby suppress deterioration of a detection signal resulting from stray light. Further, a push-pull signal, whose DC component is suppressed, is obtained by computing an output from the eight sensing portions by a predetermined formula.

Abstract: An optical pickup device is disclosed. The device includes: a light source that emits a light beam of a predetermined wavelength of about 405 nm; an objective lens being a plastic lens provided with, on at least one surface, diffraction means of a zone diffractive structure suppressing generation of aberration to be caused by a temperature change, and has a numerical aperture of 0.82 or larger for gathering the light beam emitted from the light source with respect to an optical disk; and a collimator lens disposed between the light source and the objective lens, and derives a substantially-collimated light by converting an angle of divergence of the light beam emitted from the light source.

Abstract: A photodetector to be incorporated in an optical pickup device, comprising: a photodiode that a laser light emitted from a laser diode is applied to and that outputs a signal corresponding to light amount of the laser light; and a translucent resin member configured to cover the photodiode, including a light receiving portion that the laser light is applied to and that causes the laser light to be applied to the photodiode, and a peripheral portion provided around the light receiving portion, the light receiving portion being smaller in thickness than the peripheral portion.

Abstract: A light flux from the first light source forms a converged spot on first optical information recording medium by only a refraction action of the aspheric surface, or by a combination of the refraction action and an optical action given by at least one of the first phase structure and the second phase structure, a light flux from the second light source forms a converged spot on second optical recording medium by a combination of a refraction action of the aspheric surface and an optical action given by at least one of the first phase structure and the second phase structure, and a light flux from the third light source forms a converged spot on third optical recording medium by a combination of a refraction action of the aspheric surface and an optical action given by at least one of the first phase structure and the second phase structure.

Abstract: A transmissive or reflective diffractive optical element, comprising: a substrate having a top surface, the top surface being etched into a pattern, the pattern including a periodic surface pattern of grooves formed such that when an incoming light beam is shone onto the top surface, the incoming light beam will be split into a plurality of diffracted light beams, the plurality of diffracted light beams including a plurality of primary diffracted order beams and a plurality of secondary diffracted order beams, wherein the primary diffracted order beams have a primary aggregate efficiency above ninety percent, wherein the plurality of secondary diffracted order beams have a secondary aggregate efficiency of lower than ten percent, and wherein a maximum power of the primary diffracted order beams and a minimum power of the primary diffracted order beams differ by at least ten percent of an average power of the primary diffracted order beams.

Abstract: An optical pickup device imparts different astigmatisms from each other to light fluxes in four light flux areas A through D formed around an optical axis of laser light, out of the laser light reflected on a disc. The optical pickup device also changes the propagating directions of the light fluxes in the light flux areas A through D to separate the light fluxes in the light flux areas A through D from each other. A signal light area where only signal light exists is defined on a detection surface of a photodetector. Sensing portions are arranged at a position corresponding to the signal light area. Accordingly, only the signal light is received by the sensing portions, thereby suppressing deterioration of a detection signal resulting from stray light.

Abstract: An optical disk device for recording/reproducing information on/from a multi-layer optical disk moves a light focusing point for several layers by one focus jump. The optical disk device includes a controller to detect a level of a focus error signal to change an output level of a focus drive signal, and the controller changes timing to change the output level of the focus drive signal based on the number of layers for the focus jump.

Abstract: In order that thickness reduction, weight reduction, and mass productivity improvement should be achieved in an objective lens even in the case where NA is high, an objective lens according to the present invention is a bi-convex single lens having at least one aspheric surface, and satisfies conditions: (1) 3.5<DH-S/DH-H?<4.3; (2) 3.5<DH?-T2/DT1-H<50; (3) 0.9<d/f<1.1 (NA?0.85).

Abstract: Provided is an objective lens for an optical pickup apparatus. The objective lens collects diffracted light generated by an optical path difference giving structure onto the information recording surface of an optical information recording medium as a spot and suppresses fluctuation of diffraction efficiency due to a change of using wavelength. The optical pickup apparatus using such objective lens is also provided. The total diffraction efficiency can be improved by adjusting a wavelength at which the diffraction efficiencies of a plurality of basic structures forming the optical path difference giving structure in the objective lens are maximum, in accordance with a basic structure.

Abstract: The present invention contributes to getting a reproduction/recording operation done with stability on an information recording medium by utilizing an absorption edge shifting phenomenon. An apparatus 100 according to the present invention includes: a light source 20 for emitting a laser beam; a lens 6 for condensing the beam onto an information recording medium 21; and a photodetector 19 for detecting light reflected from the medium 21, of which a recording layer includes a material that absorbs the beam at an increasing absorptance as the absorption edge of a light absorption spectrum shifts, with a rise in temperature, toward a longer wavelength range as a result of a band-to-band transition of electrons.

Abstract: There is provided an optical pick-up including first to third light sources respectively emitting first to third light beams, a first coupling lens, and an objective lens formed to converge each of the first, second and third light beams onto the first, second and third optical discs, respectively. The objective lens has a step structure including a plurality of concentrically formed refractive surface zones divided by steps, the step structure having a function of giving, at each step, an optical path length difference of approximately 2?1 to the first light beam. The first coupling lens causes the first light beam to be incident on the objective lens as a converging beam. The objective lens is positioned to satisfy a condition: ?0.35<f2×M2?f1×M1<?0.07??(1).

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: An optical system for optical pickup, which optical system is used for performing recording, reproducing, and/or erasing of information on an optical recording medium and has a simple configuration, is provided. An optical pickup device 1 includes a collimator lens system 23, a beam expander 33, and an objective lens system 34 that includes an S-SIL element 27b. The beam expander 33 includes three lens elements 33a to 33c. By moving in an optical axis direction, the two lens elements 33a and 33b included in the beam expander 33 adjust a focal point of a spot formed within an optical recording medium 28, and compensate a spherical aberration caused by the difference in depth between recording layers.

Abstract: An object of the invention is to suppress an influence of a wavefront aberration which is generated at the time of correcting a third-order spherical aberration, and realize satisfactory information recording and/or reproducing. A collimator lens 4 corrects a third-order spherical aberration which is generated depending on the thickness of a light transmissive layer from a surface of a first optical information recording medium 30, corresponding to an optimal substrate thickness of a first objective lens 6, to an intended information recording surface, assuming that the light transmissive layer thickness of the first optical information recording medium 30 which minimizes a residual third-order spherical aberration at the time of incidence of parallel light into the first objective lens 6 is defined as the optimal substrate thickness of the first objective lens 6.

Abstract: A small form factor optical disk drive is provided that incorporates a SIL/objective lens assembly. A laser for the small form factor optical disk drive has a coherence function having maxima spaced apart by intervals. The optical disk drive is configured such that a roundtrip optical path through the SIL/objective lens assembly is such that a coherence value for the laser is located in one of the intervals.

Abstract: An optical pickup apparatus and a drive apparatus having the same are provided. Second light-receiving elements or third light-receiving elements for receiving ±first-order diffraction light beams from a polarization hologram are arranged outwardly of a circular region having the optical axis of a zero-order diffraction light beam on a light detector as its center, a radius of which is expressed by (2×t/n)×(f2/f1), where f1 denotes a focal length of an objective lens, f2 denotes a focal length of a coupling lens, t denotes a maximum value of a light transmitting layer thickness, n denotes a refractive index of a light transmitting layer.

Abstract: A small form factor optical disk drive is provided that incorporates a hybrid solid immersion objective lens (SIOL). The SIOL includes a central aspheric lens portion and a surrounding diffractive optical element portion.

Abstract: An optical pickup apparatus comprising: a laser light source; an objective lens; a reflection mirror; a photodetector; and a beam splitter, the beam splitter including a first reflective film configured to generate a first phase difference corresponding to a predetermined wavelength with respect to laser light, the reflection mirror including a second reflective film configured to generate a second phase difference corresponding to the predetermined wavelength with respect to the laser light, the first reflective film and the second reflective film being formed so that a combined phase difference of the first phase difference and the second phase difference becomes substantially quarter-wave with respect to the laser light.

Abstract: An object of the invention is to provide an optical disc device, an optical head, and an information processing device that enable to advantageously record or reproduce information with respect to an information recording medium having three or more information recording surfaces with light transmissive layers of different thicknesses from each other.

Abstract: An optical pickup unit comprising: an objective lens that focuses laser light on an optical disc; a lens holder that holds the objective lens; a coil that is fitted on the lens holder and capable of driving the lens holder; and a reinforcement member that is fitted on the lens holder and reinforces strength of the lens holder.

Abstract: A laminated wave plate includes a first wave plate with a phase difference of ?1=180° with respect to a designed wavelength ?0 and a second wave plate with a phase difference of ?2=180°, in which the first wave plate and the second wave plate are arranged and laminated so that optical axes thereof intersect each other, the laminated wave plate converting an incident linearly-polarized beam into a linearly-polarized beam obtained by rotating a polarization plane of the incident linearly-polarized beam by a predetermined angle ? and outputting the converted linearly-polarized beam. When in-plane bearing angles formed by the polarization plane of the incident linearly-polarized beam and optical axes of the first and second wave plates are represented by ?1 and ?2 and an optical axis adjustment amount is represented by a, the following expressions are satisfied: ?1=?/4+a; and ?2=3?/4?a.

Abstract: A laminated half-wave plate includes: first and second wave plates having optical axes intersecting each other, wherein when phase differences of the first and second wave plates with respect to a wavelength ? are represented by ?1 and ?2, in-plane bearing angles formed by a polarization plane of a linearly-polarized beam incident on the laminated half-wave plate and the optical axes of the first and second wave plates are represented by ?1 and ?2, an angle formed by the polarization directions of the linearly-polarized beams incident on and emitted from the laminated half-wave plate is represented by ?, and an optical axis adjustment amount is represented by a, the following expressions are satisfied: ?1=180°+n×360°; ?2=180°+n×360° (where n in ?1 and ?2 is a non-negative integer); ?1=?/4+a; and ?2=3?/4?a.