Abstract: By using an offset parabolic concave mirror as a concave mirror, and arranging a lens having an entrance pupil at the geometric focal point of the offset parabolic concave mirror, a group of rays incident parallel to the optical axis of the offset parabolic concave mirror become chief rays which are telecentric with respect to an object plane orthogonal to the optical axis of the offset parabolic concave mirror, and diverging light from each object point on the object plane can be detected on a quadric image plane formed by the lens at the focal point of the offset parabolic concave mirror without blind spots. An image of the target object is detected after the beams reflected by the offset parabolic concave mirror are bent by the reflecting mirrors and made incident on the lens to reduce the size and cost of the device.

Abstract: By using an offset parabolic concave mirror as a concave mirror, and arranging a lens having an entrance pupil at the geometric focal point of the offset parabolic concave mirror, a group of rays incident parallel to the optical axis of the offset parabolic concave mirror become chief rays which are telecentric with respect to an object plane orthogonal to the optical axis of the offset parabolic concave mirror, and diverging light from each object point on the object plane can be detected on a quadric image plane formed by the lens at the focal point of the offset parabolic concave mirror without blind spots. An image of the target object is detected after the beams reflected by the offset parabolic concave mirror are bent by the reflecting mirrors and made incident on the lens to reduce the size and cost of the device.

Abstract: A spectroscope device is provided to maintain the uniformity of the central transmitting wavelength in the field of view and to minimize the broaden of the bandwidth of the transmitting wavelengths in an optical lens using an optical tunable filter (variable wavelength filter), even with a wide field of view and/or a large numerical aperture. A space is defined in which, when each beam that is incident from each off-axial object point on the object surface toward the optical lens that includes a plurality of lens elements between an object surface and a conjugate real image surface reaches the optical tunable filter, the chief ray is maintained parallel to the optical axis. Therefore, if an optical tunable filter is disposed in this space, each beam is always incident normal to the filter, so only the narrow band components at the specific central wavelength can be transmitted.

Abstract: The position of blood vessels can be more appropriately specified by means of appropriately selecting, on the basis of the conditions and components utilized, and angle between a light emitting unit optical axis of a near-infrared light emitting unit and a normal light of an irradiated surface, and angle between an optical axis of a light receiving side lens and the normal line of the irradiated surface, and an angle between a light receiving surface of a photo diode array and the light receiving unit optical axis. Thus, the subcutaneous blood vessel depth in the direction of the normal line from the irradiated surface can be specified based on changes in illumination intensity in a photodiode array. Consequently, the position of subcutaneous blood vessels can be easily specified.

Abstract: A spectroscope device is provided to maintain the uniformity of the central transmitting wavelength in the field of view and to minimize the broaden of the bandwidth of the transmitting wavelengths in an optical lens using an optical tunable filter (variable wavelength filter), even with a wide field of view and/or a large numerical aperture. A space is defined in which, when each beam that is incident from each off-axial object point on the object surface toward the optical lens that includes a plurality of lens elements between an object surface and a conjugate real image surface reaches the optical tunable filter, the chief ray is maintained parallel to the optical axis. Therefore, if an optical tunable filter is disposed in this space, each beam is always incident normal to the filter, so only the narrow band components at the specific central wavelength can be transmitted.

Abstract: The position of blood vessels can be more appropriately specified by means of appropriately selecting, on the basis of the conditions and components utilized, and angle between a light emitting unit optical axis of a near-infrared light emitting unit and a normal light of an irradiated surface, and angle between an optical axis of a light receiving side lens and the normal line of the irradiated surface, and an angle between a light receiving surface of a photo diode array and the light receiving unit optical axis. Thus, the subcutaneous blood vessel depth in the direction of the normal line from the irradiated surface can be specified based on changes in illumination intensity in a photodiode array. Consequently, the position of subcutaneous blood vessels can be easily specified.

Abstract: A light beam (L) from a light source is reflected by a half mirror (35), converted into a collimated light beam (L1) by a collimator lens (36), and transmitted through a test lens (1). Corner cube prisms (49) included in a rotary reflector (43) retroreflect the light beam (L1) transmitted through the test lens (1). When a reflected light beam (L2) is transmitted through only a non-mark portion on the test lens (1), it diffuses only slightly and therefore becomes a retroreflected light beam with a small diameter. Thus, the retroreflected light beam (L2) forms a bright image upon being focused on CCDs (40A) without any loss due to factors associated with an aperture stop (37). In contrast, a light beam (L3) transmitted through a mark (3C) on the test lens (1) largely diffuses and therefore becomes a diverging reflected light beam with a large diameter, which suffers a considerable loss due to factors associated with the aperture stop (37).

Abstract: The present invention relates to an optical device having a structure that can make the diameter of the emitted Gaussian beam smaller. The optical device is arranged between a first and second positions, and comprises a first and second optical systems separated with a focus on an intermediate position between the first and second positions. The first optical system, arranged between the first and intermediate positions, comprises a first light entrance surface on which a Gaussian beam having a beam waist, whose radius becomes w0 at the first position, is incident, and a first light emission surface from which a Gaussian beam having a beam waist, whose radius becomes w1 at the intermediate position, is emitted.

Abstract: The present invention relates to an optical device having a structure that can make the diameter of the emitted Gaussian beam smaller. The optical device is arranged between a first and second positions, and comprises a first and second optical systems separated with a focus on an intermediate position between the first and second positions. The first optical system, arranged between the first and intermediate positions, comprises a first light entrance surface on which a Gaussian beam having a beam waist, whose radius becomes w0 at the first position, is incident, and a first light emission surface from which a Gaussian beam having a beam waist, whose radius becomes w1 at the intermediate position, is emitted.