Abstract: This solid-state image sensor includes an array of photosensitive cells and an array of dispersive elements. The photosensitive cell array is comprised of a plurality of unit blocks 40, each including four photosensitive cells 2a, 2b, 2c and 2d. An optical filter 11a is arranged to cover those photosensitive cells 2a through 2d. A portion of the optical filter 11a that covers the photosensitive cells 2a and 2b is located closer to the imaging area than another portion thereof that covers the photosensitive cells 2c and 2d.

Abstract: This solid-state image sensor includes an array of photosensitive cells and an array of dispersive elements. The photosensitive cell array is comprised of a plurality of unit blocks 40, each including four photosensitive cells 2a, 2b, 2c and 2d. A condensing element 4c is further arranged to cover the photosensitive cells 2a and 2b and condenses incoming light onto the photosensitive cells 2a and 2b.

Abstract: A light-trapping sheet includes: a light-transmitting sheet having first and second principal surfaces; and a plurality of light-coupling structures arranged in an inner portion of the light-transmitting sheet, wherein: each of the plurality of light-coupling structures includes a first light-transmitting layer, a second light-transmitting layer, and a third light-transmitting layer sandwiched therebetween; a refractive index of the first and second light-transmitting layers is smaller than a refractive index of the light-transmitting sheet; a refractive index of the third light-transmitting layer is larger than the refractive index of the first and second light-transmitting layers; and the third light-transmitting layer has a two-dimensional diffraction grating parallel to the first and second principal surfaces of the light-transmitting sheet.

Abstract: A light-trapping sheet of the present disclosure includes: a plurality of light-transmitting sheets each having first and second principal surfaces; and a plurality of light-coupling structures arranged in an inner portion of each of the plurality of light-transmitting sheets at a first and second distance from the first and second principal surfaces, respectively. Each of the plurality of light-coupling structures includes a first light-transmitting layer, a second light-transmitting layer, and a third light-transmitting layer sandwiched therebetween. A refractive index of the first and second light-transmitting layers is smaller than a refractive index of the light-transmitting sheet; and a refractive index of the third light-transmitting layer is larger than the refractive index of the first and second light-transmitting layers. The third light-transmitting layer has a diffraction grating parallel to the first and second principal surfaces of the light-transmitting sheet.

Abstract: An information recording/reproducing device includes a radiation light source 1 such as a semiconductor laser, a spatial modulation element 6 that splits laser light 2 emitted from the radiation light source 1 into a large number of diffracted light rays, and an objective lens 7 that converges the large number of diffracted light rays onto different points. The laser light 2 emitted from the radiation light source 1 is split into a large number of diffracted light rays by the spatial modulation element 6, the large number of diffracted light rays are converged onto different points in the photosensitive layer 8b of the information recording medium 8 by the objective lens 7, and information is recorded in the photosensitive layer 8b of the information recording medium 8, using an assembly of these converging points. Accordingly, it is possible to provide an information recording device capable of realizing high-contrast recording in which stray light or diffraction has no influence during signal recording.

Abstract: A light-receiving device of the present disclosure includes a light-trapping sheet, and a photoelectric conversion section optically coupled thereto. The light-trapping sheet includes: a light-transmitting sheet; and a plurality of light-coupling structures arranged in an inner portion of the light-transmitting sheet. The light-coupling structure includes first, second and third light-transmitting layers. A refractive index of the first and second light-transmitting layers is smaller than that of the light-transmitting sheet; and a refractive index of the third light-transmitting layer is larger than those of the first and second light-transmitting layers. The third light-transmitting layer has a diffraction grating parallel to the light-transmitting sheet. At least a part of the photoelectric conversion section is located along an outer edge of at least one of the surfaces of the light-transmitting sheet.

Abstract: A light-trapping sheet of the present disclosure includes: a light-transmitting sheet; and light-coupling structures arranged in an inner portion of the light-transmitting sheet. The light-coupling structure includes first, second and third light-transmitting layers. A refractive index of the first and second light-transmitting layers is smaller than that of the light-transmitting sheet; and a refractive index of the third light-transmitting layer is larger than those of the first and second light-transmitting layers. The third light-transmitting layer has a diffraction grating parallel to the surfaces of the light-transmitting sheet. The light-trapping sheet further includes a transparent cover sheet opposing at least one of the surfaces of the light-transmitting sheet with a gap interposed therebetween.

Abstract: A light-trapping sheet of the present invention includes: a light-transmitting sheet 2 having first and second principal surfaces; and a plurality of light-coupling structures 3 arranged in an inner portion of the light-transmitting sheet at a first distance or more and a second distance or more from the first and second principal surfaces, respectively, wherein: each of the plurality of light-coupling structures 3 includes a first light-transmitting layer, a second light-transmitting layer, and a third light-transmitting layer arranged therebetween; a refractive index of the first and second light-transmitting layers is smaller than a refractive index of the light-transmitting sheet 2; a refractive index of the third light-transmitting layer is larger than the refractive index of the first and second light-transmitting layers; and the third light-transmitting layer has a diffraction grating parallel to the first and second principal surfaces of the light-transmitting sheet.

Abstract: A sheet and a light emitting device are provided which also emit light having an incident angle larger than or equal to a critical angle to significantly increase light extraction efficiency, prevent ambient light reflection, and suppress the occurrence of a distribution of light intensity varying depending on the direction and an imbalance in color. The light emitting device has a surface structure (13) in a surface adjacent to a light emitting element of a transparent substrate (5). The surface of the transparent substrate (5) is virtually divided into minute regions without a gap, the diameter of a largest circle inscribed in the minute region being 0.2 ?m or more and 1.5 ?m or less. Each minute region has a convex or concave shape in the surface of the transparent substrate 5. The proportions of the convex shapes and the concave shapes are P and 1?P, respectively, where P is within the range of 0.4 to 0.98.

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: In an embodiment, an optical pickup includes at least one light source for selectively emitting three light beams having blue, red, and infrared wavelengths, respectively, and an objective lens arranged so that each of the three light beams enters thereto. The objective lens includes a first grating, and a second grating formed in the same plane as the first grating. The first and second gratings each have phase steps arranged concentrically around a center axis of a lens in a region in which all the three light beams pass, and are different in phase step positions. The first grating diffracts the three light beams having the blue, red, and infrared wavelengths in a 2nd order, a 1st order, and the 1st order, respectively. On the other hand, the second grating diffracts the three light beams having the blue, red, and infrared wavelengths in the 1st order, the 1st order, and the 1st order, respectively.

Abstract: An optical element including: a first light transmitting layer having a first sawtooth blazed surface, the first light transmitting layer including a plurality of first light-transmitting slopes defining a first blaze angle ?; and a second light transmitting layer having a second sawtooth blazed surface including a plurality of second light-transmitting slopes defining a second blaze angle ?, the second light transmitting layer being in contact with the first sawtooth blazed surface of the first light transmitting layer. A tilting direction of the first light-transmitting slope and a tilting direction of the second light-transmitting slope are opposite.

Abstract: In an embodiment, an optical pickup includes at least one light source for selectively emitting three light beams having blue, red, and infrared wavelengths, respectively, and an objective lens arranged so that each of the three light beams enters thereto. The objective lens includes a first grating, and a second grating formed in the same plane as the first grating. The first and second gratings each have phase steps arranged concentrically around a center axis of a lens in a region in which all the three light beams pass, and are different in phase step positions. The first grating diffracts the three light beams having the blue, red, and infrared wavelengths in a 2nd order, a 1st order, and the 1st order, respectively. On the other hand, the second grating diffracts the three light beams having the blue, red, and infrared wavelengths in the 1st order, the 1st order, and the 1st order, respectively.

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: Light-splitting elements are arranged in at least two columns and two rows to form two pairs 1a, 1b and 1c, 1d. Each element splits incident light into light rays and makes them fall on a portion of a photosensing section right under itself and an adjacent photosensitive cell. The element 1a splits the incident light so that a primary color ray C1 and its complementary color ray C1? enter an adjacent cell 2b and an underlying cell 2a, respectively. The element 1b makes a primary color ray C2 and its complementary color ray C2? enter an underlying cell 2a and an adjacent cell 2a, respectively. The element 1c does the same as the element 1b. And the element 1d makes a primary color ray C3 and its complementary color ray C3? enter an adjacent cell 2c and an underlying cell 2d, respectively. These photosensitive cells 2 perform photoelectric conversion, thereby outputting an electrical signal representing the intensity of the incident light.

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: 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.

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: 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.