Abstract: Provided is a small and handy phototherapy apparatus that receives an ultraviolet light source in a housing, and is able to appropriately irradiate a patient with ultraviolet light emitted from the ultraviolet light source while not irradiating an operator with the ultraviolet light. The housing of the phototherapy apparatus has a light guide path through which the ultraviolet light from the ultraviolet light source passes, a leading end of the light guide path has an irradiation window for emitting the ultraviolet light to the outside, and an observation window or windows are formed in at least one side surface of the light guide path near the irradiation window, whereby irradiation treatment while observing an affected part becomes possible, and irradiation of only the affected part with the ultraviolet light becomes possible without erroneously irradiating other parts with the ultraviolet light.

Abstract: A photoelectric encoder has a telecentric optical system in which a first lens and an aperture located at a focal position of the first lens are interposed between a main scale and a photoreceptor. At least a second lens is interposed between the aperture and the photoreceptor with a focus of the second lens on the aperture, thereby constituting a bilateral telecentric optical system. This makes it possible to improve the signal detection efficiency and increase the assembly tolerance.

Abstract: A displacement measuring device including a scale, and an optical readhead including an index pattern and a light receiving element is provided. A bright/dark pattern arising from a scale grating is detected by the readhead to measure displacement. In various embodiments, a magnification of the pattern is adjusted by the spacing between at least a lens element, aperture element, and detection plane of the readhead. An aperture can be designed to provide a diffraction-limited telecentric imaging configuration that filters an image of the scale grating to provide a sinusoidal intensity pattern that supports highly interpolated measurements. An aperture dimension, selected in relation to the grating pitch and other parameters, can provide a desirable combination of readhead operating characteristics including one or more of a desired depth of field; degree of spatial filtering; and optical signal power.

Abstract: The displacement detector includes: a light source 140; a beam splitter 170 for dividing the light, which is sent from the light source 140, into two beams of light; reflection mirrors 181, 182 provided for the two beams of light sent from the beam splitter 170, for reflecting these two beams of light and making them incident upon a scale 110; and corner cubes 191, 192 provided for the beams of diffracted light, which are generated when two beams of light incident upon the scale 110 are diffracted by the diffraction grating 111, wherein the corner cubes 191, 192 retroreflect the diffracted light and make the light incident upon the scale as retroreflected light. The incident angle to grating groove formed between the incident light and the normal line vector of the scale is larger than the diffraction angle formed between the retroreflected light and the normal line vector of the scale.

Abstract: A photoelectric encoder has a telecentric optical system in which a first lens and an aperture located at a focal position of the first lens are interposed between a main scale and a photoreceptor. At least a second lens is interposed between the aperture and the photoreceptor with a focus of the second lens on the aperture, thereby constituting a bilateral telecentric optical system. This makes it possible to improve the signal detection efficiency and increase the assembly tolerance.

Abstract: A photoelectric encoder is provided, which emits light from a light source to a main scale and an index scale that can relatively move with respect to each other and obtains a light-receiving signal by interaction between the main scale and the index scale. The photoelectric encoder uses as the light source an incoherent semiconductor light source (white LED) in which a full width at half maximum of an emission spectrum is wider than that of a monochromatic semiconductor light source. Thus, it is possible to reduce an effect of a gap change on an output signal of the encoder and make positional adjustment easier, thereby improving misalignment characteristics.

Abstract: A displacement measuring device including a scale, and an optical readhead including an index pattern and a light receiving element is provided. A bright/dark pattern arising from a scale grating is detected by the readhead to measure displacement. In various embodiments, a magnification of the pattern is adjusted by the spacing between at least a lens element, aperture element, and detection plane of the readhead. An aperture can be designed to provide a diffraction-limited telecentric imaging configuration that filters an image of the scale grating to provide a sinusoidal intensity pattern that supports highly interpolated measurements. An aperture dimension, selected in relation to the grating pitch and other parameters, can provide a desirable combination of readhead operating characteristics including one or more of a desired depth of field; degree of spatial filtering; and optical signal power.

Abstract: A displacement measuring device including a scale, and an optical readhead including an index pattern and a light receiving element is provided. A bright/dark pattern arising from a scale grating is detected by the readhead to measure displacement. In various embodiments, a magnification of the pattern is adjusted by the spacing between at least a lens element, aperture element, and detection plane of the readhead. An aperture can be designed to provide a diffraction-limited telecentric imaging configuration that filters an image of the scale grating to provide a sinusoidal intensity pattern that supports highly interpolated measurements. An aperture dimension, selected in relation to the grating pitch and other parameters, can provide a desirable combination of readhead operating characteristics including one or more of a desired depth of field; degree of spatial filtering; and optical signal power.

Abstract: The displacement detector includes: a light source 140; a beam splitter 170 for dividing the light, which is sent from the light source 140, into two beams of light; reflection mirrors 181, 182 provided for the two beams of light sent from the beam splitter 170, for reflecting these two beams of light and making them incident upon a scale 110; and corner cubes 191, 192 provided for the beams of diffracted light, which are generated when two beams of light incident upon the scale 110 are diffracted by the diffraction grating 111, wherein the corner cubes 191, 192 retroreflect the diffracted light and make the light incident upon the scale as retroreflected light. The incident angle to grating groove formed between the incident light and the normal line vector of the scale is larger than the diffraction angle formed between the retroreflected light and the normal line vector of the scale.

Abstract: A photoelectric encoder is provided, which emits light from a light source to a main scale and an index scale that can relatively move with respect to each other and obtains a light-receiving signal by interaction between the main scale and the index scale. The photoelectric encoder uses as the light source an incoherent semiconductor light source (white LED) in which a full width at half maximum of an emission spectrum is wider than that of a monochromatic semiconductor light source. Thus, it is possible to reduce an effect of a gap change on an output signal of the encoder and make positional adjustment easier, thereby improving misalignment characteristics.

Abstract: A photoelectric encoder includes a main scale with a grating, and a light receiving portion with an index grating and a light receiving element. A bright/dark pattern obtained at least by the grating on the main scale is detected by the light receiving portion moved relative to the main scale. A lens and/or an aperture are inserted between the main scale and the light receiving portion, and a magnification of an image is set by adjusting distances among the lens or the aperture, the main scale and the light receiving portion.

Abstract: A displacement measuring device including a scale, and an optical readhead including an index pattern and a light receiving element is provided. A bright/dark pattern arising from a scale grating is detected by the readhead to measure displacement. In various embodiments, a magnification of the pattern is adjusted by the spacing between at least a lens element, aperture element, and detection plane of the readhead. An aperture can be designed to provide a diffraction-limited telecentric imaging configuration that filters an image of the scale grating to provide a sinusoidal intensity pattern that supports highly interpolated measurements. An aperture dimension, selected in relation to the grating pitch and other parameters, can provide a desirable combination of readhead operating characteristics including one or more of a desired depth of field; degree of spatial filtering; and optical signal power.

Abstract: An optical encoder comprises a main scale (1) having scale gratings (11) formed thereon with a certain angular pitch along a measurement axis (x1) that describes a circular arc. It also comprises a detection bead (2) having photoreceptive optical gratings (7) formed thereon. The detection head is arranged relatively movable along the measurement axis (x1), opposing to the main scale (1). The photoreceptive optical gratings (7) on the detection head (2) have transparent and opaque portions alternately arranged with a certain distance pitch along a straight, grating arrangement axis (x2).