Abstract: A diffraction grating lens of the present invention includes a lens base 51 having a surface 51b obtained by providing a diffraction grating 52 on a base shape. The diffraction grating 52 includes a plurality of zones 61A and 61B and a plurality of first diffraction steps 65A and second diffraction steps 65B located between the plurality of zones; the lens base is made of a first material whose refractive index is n1(?) at a working wavelength ?; and the first diffraction steps 65A and the second diffraction steps 65B have substantially the same height d. The height d satisfies Expression (1) below, where m denotes a diffraction order. A first surface 66A on which tips 63A of the first diffraction steps 65A are located and a second surface 66B on which tips 63B of the second diffraction steps 65B are located are at different positions from each other on an optical axis 53.

Abstract: A diffractive lens according to the present invention has the function of focusing light. The diffractive lens has a side on which a diffraction grating is arranged on either an aspheric surface or a spherical surface in its effective area. The diffraction grating has n0 phase steps, which are arranged concentrically around the optical axis of the diffractive lens. And the radius rn of the circle formed by an nth one (where n is an integer that falls within the range of 0 through n0) of the phase steps as counted from the optical axis of the diffractive lens satisfies rn=?{square root over (a{(n+c+dn)?b(n+c+dn)m})}{square root over (a{(n+c+dn)?b(n+c+dn)m})} where a, b, c and m are constants that satisfy a>0, 0?c<1, m>1, and 0.05 ? b 0 < b < b 0 b 0 = 1 mn 0 m - 1 and dn is an arbitrary value that satisfies ?0.25<dn<0.25.

Abstract: A diffractive optical element according to the present invention includes: a lens body 11 with a blazed grating 13 on an aspheric surface 11a thereof; and an optical adjustment layer 15 that covers the diffraction grating 13. The lens body 11 is made of a first material 14a and the optical adjustment layer 15 is made of a second material 14b that has a higher refractive index than the first material 14a. The diffraction grating 13 has a number of ring zones that are arranged concentrically around an optical axis, where the height of each ring zone with respect to the aspheric surface 11a of the lens body 11 is represented by an increasing function of a distance r from the optical axis. The increasing function is represented by a phase polynomial that uses the distance r as a variable and that has a magnitude of 3/4? to 7/4? when r=0.

Abstract: A transparent sheet for use with a light emitting body with one of surfaces of the transparent sheet being adjacent to the light emitting body, wherein the other surface of the sheet is divided into a plurality of minute regions ?, a largest inscribed circle of the minute regions ? having a diameter from 0.2 ?m to 1.5 ?m, each of the minute regions ? being adjoined by and surrounded by two or more other ones of the plurality of minute regions ?, the plurality of minute regions ? include a plurality of minute regions ?b which are randomly selected from the plurality of minute regions ? so as to constitute 40% to 98% of the minute regions ? and a plurality of minute regions ?a which constitute the remaining portion of the minute regions ?, the minute regions ?a are provided with a first tiny element which has thickness d and effective refractive index na, and the minute regions ?b are provided with a second tiny element which has thickness d and effective refractive index nb, nb being greater than na.

Abstract: An imaging photodetection device includes a plurality of photodetectors (6) arrayed on a substrate (5) one-dimensionally or two-dimensionally, a low refractive index transparent layer (12) formed above the plural photodetectors, and a plurality of columnar or plate-like high refractive index transparent sections (13) embedded in the low refractive index transparent layer along the array direction of the plural photodetectors. At least two of the photodetectors correspond to one of the high refractive index transparent sections. Light entering the low refractive index transparent layer and the high refractive index transparent sections passes therethrough to be separated into a 0th-order diffracted light, a 1st-order diffracted light and a ?1st-order diffracted light by a phase shift occurring on the wavefront. Thereby, improvement in the efficiency for light utilization and pixel densification can be realized.

Abstract: Light emitted from a radiation light source 1 passes through a diffraction grating 3a and is separated into transmitted light a and +1st/?1st order diffracted lights b, c. These lights are collected through an objective lens 7 on tracks of an optical disc 8 in a partially overlapped state. Light reflected by the tracks passes through the objective lens 7 and is incident upon light diverging means 13a. Subsequently, light corresponding to the transmitted light “a” diverges into two light beams that are respectively incident upon light detection regions A1, A2, light corresponding to the diffracted lights “b” and “c” respectively diverges into two light beams that are respectively incident upon light detection regions B1, B2, and C1, C2. A tracking error signal associated with the tracks of the optical disc 8 is generated by combining signals detected in the light detection regions A1, A2, B1, B2, C1, and C2.

Abstract: An optical element according to the present invention is an optical element including: a first light transmitting layer having a first sawtooth blazed surface 10, the first light transmitting layer including a plurality of first light-transmitting slopes 12 defining a first blaze angle ?; and a second light transmitting layer having a second sawtooth blazed surface 20 including a plurality of second light-transmitting slopes 22 defining a second blaze angle ?, the second light transmitting layer being in contact with the first sawtooth blazed surface 10 of the first light transmitting layer. A tilting direction of the first light-transmitting slope 12 and a tilting direction of the second light-transmitting slope 22 are opposite.

Abstract: When first-order diffracted beams leak into a region, which is for receiving only a zeroth-order diffracted beam from an optical disc, due to positional displacement between an objective lens and a hologram element, an offset compensation signal includes an AC component, the offset compensation signal preferably including a DC component only. Accordingly, there may be caused deterioration in a modulation degree of the tracking error (TE) signal. A partial light shielding element 110 is formed on a hologram surface 112a along boundaries between a light receiving region (121a), which receives a zeroth-order diffracted beam, and light receiving regions (121b, 121c), which receive the zeroth-order diffracted beam and first-order diffracted beams, so as to cover the light receiving region (121a). Further, the partial light shielding element 110 shifts phases of transmitted light beams by ?, whereby the TE signal is offset-compensated, and the modulation degree can be improved.

Abstract: An imaging photodetection device (4) includes: a plurality of photodetectors (6) that are arrayed on a substrate (5) at least along a first direction; a transparent low refractive index layer (12) that is formed above the plurality of photodetectors; and a plurality of transparent high refractive index sections (13) that are embedded in the transparent low refractive index layer along the first direction. On a cross-section of the transparent high refractive index sections orthogonal to the substrate and along the first direction, central axes (14) of the transparent high refractive index sections are bent stepwise. Light that enters the transparent low refractive index layer and the transparent high refractive index section passes therethrough to be separated into 0th-order diffracted light, 1st-order diffracted light, and ?1st-order diffracted light. Thereby, improvement in the efficiency of light utilization and pixel densification can be realized.

Abstract: A solid-state image sensor according to the present invention includes: a semiconductor layer 7, which has a first surface and a second surface that is opposite to the first surface; a photosensitive cell array, which has been formed in the semiconductor layer 7 to receive light through both of the first and second surfaces; and at least one dispersive element array, which is arranged on the same side as at least one of the first and second surfaces so as to face the photosensitive cell array. The photosensitive cell array includes first and second photosensitive cells 2a and 2b. And the dispersive element array makes light rays falling within mutually different wavelength ranges incident on the first and second photosensitive cells 2a and 2b, respectively.

Abstract: A plurality of imaging regions are provided in one-to-one correspondence with a plurality of optical systems and are disposed on optical axes of the respective optical systems. Each imaging region has a plurality of pixels. The imaging apparatus further comprises an origin detecting means for detecting an origin of each imaging region, a pixel position specifying means for specifying positions of a plurality of pixels included in each imaging region using the origin as a reference, and a combination means for combining a plurality of images captured by the respective imaging regions. Thereby, it is possible to make a thin imaging apparatus capable of being easily assembled.

Abstract: A sheet of the present invention is a sheet which is to be used such that light from a light emitting body impinges on one of surfaces of the sheet and outgoes from the other surface. The other surface of the sheet includes a plurality of minute regions 13, a largest inscribed circle of the minute regions 13 having a diameter from 0.2 ?m to 2 ?m. Each of the plurality of minute regions 13 is adjoined by and surrounded by some other ones of the plurality of minute regions 13. The plurality of minute regions 13 include a plurality of minute regions 13a which are randomly selected from the plurality of minute regions 13 so as to constitute 20% to 80% of the minute regions 13 and a plurality of minute regions 13b which constitute the remaining portion of the minute regions 13. Light transmitted through the plurality of minute regions 13a and light transmitted through the plurality of minute regions 13b have a phase difference of ?.

Abstract: In a three-dimensional video display apparatus, accommodation and convergence among physiological characteristics of eyes are abandoned, thereby resulting in generation of unnatural three-dimensional video. For example, even when eyes are moved, a screen is not changed, and a cardboard effect and/or a miniature garden effect may be caused, so that the eyes may be greatly fatigued. Light emission sources 1R, 1G, and 1I, holograms 3R, 3G, and 3I, and a transparent display component 4 are provided, and a plurality of reflectors 6 are formed in the display component 4 so as to be positioned at intersections in a space lattice.

Abstract: A light emitting device 107 includes a surface structure 113 in a surface of a transparent substrate 105 which is adjacent to a light emitting body. The surface of the transparent substrate 105 is divided into minute regions, without leaving any gap therebetween, such that the diameter of the largest one of the inscribed circles of the minute regions is from 0.2 ?m to 1.5 ?m. Each of the minute regions is in the form of a protrusion or recess. The proportion of the protrusions and the proportion of the recesses are P and 1-P, respectively, and P is in the range of 0.4 to 0.98. At least part of the minute regions has a micro periodic structure 114 that is formed by indentations and projections.

Abstract: A focus error signal is generated by a first-order diffracted light diffracted by regions 23b, 24b on a hologram plane 2a, and an offset of a tracking error signal is canceled by first-order diffracted light diffracted by regions 21a, 22a, 23a, 24a on the hologram plane 2a. Consequently, even when there is an error in the substrate thicknesses of optical discs, jitter of a reproduction signal at a focus control point can be reduced by decreasing the distance between the focus control point and the point where the jitter is minimized.

Abstract: A plurality of imaging regions are provided in one-to-one correspondence with a plurality of optical systems and are disposed on optical axes of the respective optical systems. Each imaging region has a plurality of pixels. The imaging apparatus further comprises an origin assigning means for assigning an origin of each imaging region, a pixel position specifying means for specifying positions of a plurality of pixels included in each imaging region using the origin as a reference, and a combination means for combining a plurality of images captured by the respective imaging regions. Thereby, it is possible to make a thin imaging apparatus capable of being easily assembled.

Abstract: A transparent sheet usable in the state where one of surfaces thereof is adjacent to a light emitting body, wherein the other surface of the sheet is divided into a plurality of tiny areas ? having such a size that a maximum circle among circles inscribed thereto has a diameter of 0.5 ?m or greater and 3 ?m or less with no gap; the tiny areas ? include a plurality of tiny areas ?1 randomly selected from the plurality of tiny areas ?, and the remaining plurality of tiny areas ?2; the tiny areas ?1 each include an area ?1a along a border with the corresponding tiny area ?2, and the remaining area ?1b; the tiny areas ?2 each include an area ?2a along a border with the corresponding tiny area ?1, and the remaining area ?2b; the height of the tiny areas ?1b is d/2; the height of the tiny areas ?1a is between zero to d/2; the depth of the tiny areas ?2a is d/2; the depth of the tiny areas ?2b is between zero to d/2; and d is in the range of 0.2 ?m or greater and 3.0 ?m or less.

Abstract: A surface of a transparent substrate 5 which is adjacent to a light emitting body has a surface structure 13 that is defined by dividing the surface into a plurality of linear segments of width w which are inclined so as to extend in a specific direction in a plane of the surface and dividing the linear segments into minute regions aligned along the longitudinal direction of the linear segments such that the largest inscribed circle of the minute regions has a diameter from 0.2 ?m to 1.5 ?m. Each of the minute regions is formed by a raised or recessed portion formed in the surface of the transparent substrate 5. The proportion of the raised portions and the proportion of the recessed portions, P and 1?P, are determined such that P is in the range of 0.4 to 0.98.

Abstract: A tracking error signal is generated with stability without being easily affected by a distribution fluctuation of light reflected from an optical disc or by a lens shift. An optical disc drive according to the present invention includes: an objective lens 5 with an aperture radius r0 for converging a light beam emitted from a light source 1; a polarizing hologram substrate 2 for dividing the beam reflected from the optical disc 6 into branched light beams; a photodetector substrate 6, on which at least some of the light beams are incident to generate signals representing the intensities of the light beams; and a shielding mask 16 for cutting off the beam partially.

Abstract: The solid state image sensor of this invention includes multiple units, each of which includes first and second photosensitive cells 2a, 2b and a dispersive element 1a facing the first cell 2a. The element 1a passes a part of incoming light with a first color component to the second cell 2b. The first cell 2a receives a smaller quantity of light with the first color component than that of the light with the first color component incident on the dispersive element. The second cell 2b receives a greater quantity of light with the first color component than that of the light with the first color component incident on the dispersive element.