Abstract: A flux for a solder paste includes rosin, an activator and a solvent. The solvent includes a monoalkylene glycol-based solvent and a solid solvent that is solid at 20° C. The total content of the monoalkylene glycol-based solvent and the solid solvent ranges from 40% by mass to 60% by mass with the total amount of the flux as 100%. The content of the solid solvent ranges from 5% by mass to 25% by mass with the total amount of the flux as 100%.

Abstract: A surface inspection apparatus includes a differential interference contrast detection system. Illumination light is emitted to positions deviated by a predetermined shear amount as two illumination spots having different phases. Light is generated in first and second polarization directions different from each other from interference light obtained by interfering reflected light of the two illumination spots from a surface of a sample. Light in the first and second polarization directions is converted to generate first and second interference signals. A signal processing device is configured to process the first and second interference signals, and the first and second polarization directions of the light generated by the differential interference contrast detection system are set such that an intensity of the first interference signal and an intensity of the second interference signal are the same at an operation point at which there is no phase difference between the two illumination spots.

Abstract: A head-mounted display achieves both miniaturization and high efficiency of an optical system and expansion of an eye box. In order to achieve the above-described object, a head-mounted display that displays an image within a visual field of a user is provided. The head-mounted display includes: an image display unit that generates an image to be displayed; a projection unit that projects image light from the image display unit; an image rotation and replication unit that expands an eye box of projection light from the projection unit; and a waveguide unit that transmits image light from the image rotation and replication unit to a pupil of the user. The image rotation and replication unit includes an incidence surface, an emission surface, and at least two reflection surfaces, and an angle formed by the incidence surface and the emission surface is greater than 90°.

Abstract: A flux for a solder paste includes rosin, an activator and a solvent. The solvent includes a monoalkylene glycol-based solvent and a solid solvent that is solid at 20° C. The total content of the monoalkylene glycol-based solvent and the solid solvent ranges from 40% by mass to 60% by mass with the total amount of the flux as 100%. The content of the solid solvent ranges from 5% by mass to 25% by mass with the total amount of the flux as 100%.

Abstract: There is provided a highly efficient virtual image projection device in a small size that displays images of high luminance in which an illumination system is reduced in size with no degradation in an effective luminous light beam. A virtual image projection device that shows video to a human eye includes a virtual light source surface (116) that emits a light beam in a predetermined angular distribution, an image forming lens (117) that condenses the light beam from the virtual light source surface (116), and a display (120) that creates video. When the virtual light source surface (116) is disposed at a nearly focal position on the front side of the image forming lens (117), the display (120) is disposed at a nearly focal position on the rear side of the image forming lens.

Abstract: According to the invention, a light guide plate-type video display device and a video display system that are capable of displaying a video with less color deviation and less video distortion are provided. A video display device 101 configured to display a video includes a video projection unit 200 configured to project video light, a video deflection unit 210, and a light guide portion 230. The video deflection unit 210 deflects video light emitted by the video projection unit 200 and causes the video light to propagate to the light guide portion 230, and the light guide portion 230 causes the entered video light to propagate therein and outputs the video light. Here, the video deflection unit 210 or the light guide portion 230 is configured to reduce color dispersion of the video light outputted from the light guide portion 230.

Abstract: A solder paste includes a solder powder and a flux. The flux includes a rosin, an activator, a solvent, and a thixotropic agent containing a polyethylene glycol. A content of the polyethylene glycol is 10 mass % to 20 mass % with respect to a total mass of the flux, a content of the thixotropic agent excluding the polyethylene glycol is 5 mass % or less with respect to the total mass of the flux, and a content of the rosin is more than 15 mass % and 50 mass % or less with respect to the total mass of the flux.

Abstract: A virtual image projection device that generates image light includes a light source that emits light; a microlens array that emits the light, which is emitted from the light source, as light having a predetermined angle distribution; an imaging lens that concentrates the light from the microlens array; a display unit that is irradiated with the light, which is concentrated by the imaging lens, to generate an image; and a projection unit that projects the image, which is generated by the display unit, as image light. The microlens array is disposed such that short side directions of lens cells do not line up straight.

Abstract: The present invention provides a light-guiding plate which is applicable to incident rays over a wide ray angular range and wide wavelength rage, and is able to suppress a decrease in optical efficiency. A light-guiding plate 200 having a light diffracting portion 1200 for diffracting incident light by a multiple-recorded hologram is configured such that, in the light diffracting portion, when light 1210 of a single wavelength having a certain angular range is incident, at least two or more outgoing rays 1220 are discretely emitted with a first angular space ?s, and the emitted rays each have a second angular range ?a, and the first angular space ?s is equal to or larger than the second angular range ?a.

Abstract: A virtual image projection device that generates image light includes a light source that emits light; a microlens array that emits the light, which is emitted from the light source, as light having a predetermined angle distribution; an imaging lens that concentrates the light from the microlens array; a display unit that is irradiated with the light, which is concentrated by the imaging lens, to generate an image; and a projection unit that projects the image, which is generated by the display unit, as image light. The microlens array is disposed such that short side directions of lens cells do not line up straight.

Abstract: Both uniformity of brightness and uniformity of color of the outside world are seen via a waveguide. A video image is reflected by a partial reflection surface inside the waveguide that includes an incident surface on which video image light is incident, first and second internal reflection surfaces that propagate the video image light incident from the incident surface while totally reflecting the video image light, and are substantially parallel to each other. A plurality of partial reflection surfaces that reflect a part of the video image light propagating by being totally reflected by the first and second internal reflection surfaces, output the part of the video image light as output light from the first internal reflection surface to the outside of the waveguide, and transmit the part of the video image light being incident, and are disposed substantially parallel to each other inside the waveguide.

Abstract: An image display device projecting an image to a user includes: an image generation unit that generates image light; a projection optical unit that projects the image light generated by the image generation unit; an image light duplication unit that duplicates and emits the image light projected by the projection optical unit; and a light-guiding unit that projects the image light duplicated by the image light duplication unit to a user, in which the projection optical unit includes at least one projection lens, and in which an interval at which the image light duplication unit duplicates the image light is smaller than an outer diameter of the projection lens.

Abstract: To provide a wide eye box and are capable of displaying a video having uniform luminance, it is provided a video display apparatus comprising: a video projection unit configured to project video light; a video light replication unit configured to replicate the video light; and a light guiding unit configured to transmit the video light through an inside of the light guiding unit, wherein the video light replication unit is configured to transmit the video light emitted from the video projection unit to the light guiding unit, wherein the light guiding unit is configured to transmit the video light that has entered through the inside to output the video light, and wherein the video light replication unit is configured to replicate the video light that has entered the video light replication unit so that a luminance distribution of the video light output from the light guiding unit is uniform.

Abstract: There is provided a highly efficient virtual image projection device in a small size that displays images of high luminance in which an illumination system is reduced in size with no degradation in an effective luminous light beam. A virtual image projection device that shows video to a human eye includes a virtual light source surface (116) that emits a light beam in a predetermined angular distribution, an image forming lens (117) that condenses the light beam from the virtual light source surface (116), and a display (120) that creates video. When the virtual light source surface (116) is disposed at a nearly focal position on the front side of the image forming lens (117), the display (120) is disposed at a nearly focal position on the rear side of the image forming lens.

Abstract: A light guide plate includes: first and second internal reflective surfaces that are approximately parallel and propagate incoming image light while totally reflecting the image light; a partially reflective surface array that has a plurality of partially reflective surfaces arranged in a direction of propagating image light, the partially reflective surfaces being inclined at a predetermined angle and partially reflecting the image light; and a uniforming element that uniforms intensity distribution of image light which is reflected by the partially reflective surface array to be projected from the light guide plate. As the uniforming element, the partially reflective surface array is divided into a plurality of segments along a direction of propagating image light, and the inter-surface spacing of the partially reflective surfaces or the reflectivity of the partially reflective surfaces is configured to vary from segment to segment.

Abstract: An image display device projecting an image to a user includes: an image generation unit that generates image light; a projection optical unit that projects the image light generated by the image generation unit; an image light duplication unit that duplicates and emits the image light projected by the projection optical unit; and a light-guiding unit that projects the image light duplicated by the image light duplication unit to a user, in which the projection optical unit includes at least one projection lens, and in which an interval at which the image light duplication unit duplicates the image light is smaller than an outer diameter of the projection lens.

Abstract: Both uniformity of brightness and uniformity of color of the outside world are seen via a waveguide. A video image is reflected by a partial reflection surface inside the waveguide that includes an incident surface on which video image light is incident, first and second internal reflection surfaces that propagate the video image light incident from the incident surface while totally reflecting the video image light, and are substantially parallel to each other. A plurality of partial reflection surfaces that reflect a part of the video image light propagating by being totally reflected by the first and second internal reflection surfaces, output the part of the video image light as output light from the first internal reflection surface to the outside of the waveguide, and transmit the part of the video image light being incident, and are disposed substantially parallel to each other inside the waveguide.

Abstract: A head mounted display has a display unit to generate a displayed image, an illumination unit to emit illumination light to the display unit, a projection unit to project image light from the display unit, and a light guide unit to transmit image light from the projection unit to pupils of a user. Here, the illumination unit has light source units, a microlens array that is illuminated by light emitted from the light source units and becomes a virtual secondary light source, a condensing optical member to focus light from the microlens array on the display unit, and a diffusion plate to diffuse light from the microlens array, and the diffusion plate is arranged closer to the condensing optical member than to the microlens array. As a result, a conjugate image is inhibited from being generated with the adoption of a microlens array.

Abstract: The video display device includes a laser light source unit, a video processing unit that outputs a video gradation signal, a current gain signal, and a current offset signal, a laser driver that outputs the drive current based on the video gradation signal, the power supply gain signal, and the current offset signal, and a dimming level processing unit that divides a dimming level for designating brightness of a video into a plurality of dimming modes and divides the dimming level into in-mode levels within the divided dimming modes, wherein the video processing unit includes a video gradation value output unit that outputs the video gradation signal obtained by scaling and offsetting a gradation value of the video based on the dimming mode and the in-mode level, a current gain output unit that outputs the current gain signal depending on the dimming mode.

Abstract: According to the present invention, in an image display device that displays two images in parallel, a peak current for light source driving and continuation of a peak current are suppressed without reducing luminance of a display image. An image display device includes a light source unit, two panel units, and a timing control unit. A period of one frame of an image displayed by each panel unit has a standby period in which the panel unit is not illuminated by the light source unit for image generation and a lighting period in which the panel unit is illuminated by the light source unit. The timing control unit controls an operation timing such that the periods of one frame of the images displayed by the respective panel units overlap, and frame start times of the periods are shifted from each other by a predetermined delay time.