Abstract: In order to provide an optical system to be installed in a projection system which is capable of allowing a patient to view a clear image in a diagnostic imaging apparatus, the optical system according to the present invention includes a Fresnel lens having a base material and a plurality of annular sections arranged around a center axis on a reference surface of the base material, and a deflection element configured to deflect light from the Fresnel lens. In a cross section including the center axis, an inclination angle of the annular sections to the reference surface changes asymmetrically between from a middle point of one and other ends of the Fresnel lens to the one end and from the middle point to the other end.

Abstract: An image forming apparatus including: a movable intermediate transfer member onto which a toner image borne by an image bearing member is to be transferred; a detection unit configured to irradiate the toner image on the intermediate transfer member with light to detect reflected light; and a control unit configured to adjust a condition for forming the toner image based on a detection result of the detection unit, wherein a plurality of grooves extending along a movement direction of the intermediate transfer member are formed in a surface of the intermediate transfer member in a width direction intersecting the movement direction, and wherein grooves, formed within a range of the intermediate transfer member to which the light is irradiated by the detection unit, among the plurality of grooves are formed so that intervals each between adjacent grooves with respect to the width direction are regularly changed within a predetermined range.

Abstract: In an ocular optical system including a first lens having positive refractive power, a second lens having negative refractive power, a third lens having positive refractive power, and a fourth lens having positive refractive power which are arranged in this order from an object side to an observation side, the shape and position of each lens is set appropriately to increase the angle of view and to minimize on-axis and magnification chromatic aberrations.

Abstract: An image forming apparatus including: a movable intermediate transfer member onto which a toner image borne by an image bearing member is to be transferred; a detection unit configured to irradiate the toner image on the intermediate transfer member with light to detect reflected light; and a control unit configured to adjust a condition for forming the toner image based on a detection result of the detection unit, wherein a plurality of grooves extending along a movement direction of the intermediate transfer member are formed in a surface of the intermediate transfer member in a width direction intersecting the movement direction, and wherein grooves, formed within a range of the intermediate transfer member to which the light is irradiated by the detection unit, among the plurality of grooves are formed so that intervals each between adjacent grooves with respect to the width direction are regularly changed within a predetermined range.

Abstract: In order to provide an optical system to be installed in a projection system which is capable of allowing a patient to view a clear image in a diagnostic imaging apparatus, the optical system according to the present invention includes a Fresnel lens having a base material and a plurality of annular sections arranged around a center axis on a reference surface of the base material, and a deflection element configured to deflect light from the Fresnel lens. In a cross section including the center axis, an inclination angle of the annular sections to the reference surface changes asymmetrically between from a middle point of one and other ends of the Fresnel lens to the one end and from the middle point to the other end.

Abstract: In an ocular optical system including a first lens having positive refractive power, a second lens having negative refractive power, a third lens having positive refractive power, and a fourth lens having positive refractive power which are arranged in this order from an object side to an observation side, the shape and position of each lens is set appropriately to increase the angle of view and to minimize on-axis and magnification chromatic aberrations.

Abstract: Provided is a finder system, including: an observation optical system configured to convert a subject image formed on a predetermined surface into an erect image via an erect image forming member, and cause the erect image to be transmitted through a first optical surface that is inclined with respect to an optical axis, thereby observing the erect image via an eyepiece lens; and a display optical system configured to cause an image indicating display information of a display member to be reflected on the first optical surface, thereby observing the image via the eyepiece lens in the same field of view as the subject image. The display optical system includes an optical member including at least two reflection surfaces and a lens unit having a positive refractive power, along an optical path between the display member and the eyepiece lens in the stated order.

Abstract: An ocular optical system used to view an image displayed on an image display surface, which includes a first lens having positive refractive power, a second lens of meniscus shape having negative refractive power with its concave surface facing the image display surface side, and a third lens having positive refractive power arranged in this order from the image display surface side to a viewer side. A focal length of the first lens, a focal length of the second lens and a focal length of the entire system need to be determined suitably.

Abstract: The illumination apparatus includes a reflector unit to reflect a light flux from a light source. The reflector unit includes a first reflector and a second reflector whose relative positions are changeable to change an illumination angle. At a first illumination angle, the second reflector is disposed inside the first reflector, and the light flux from the light source is reflected by the second reflector to exit from the reflector unit. At a second illumination angle smaller than the first illumination angle, the first reflector is disposed further on a light exit side than the second reflector, and the light flux from the light source is reflected by at least one of the first and second reflectors to exit from the reflector unit. A distance between the light source and the second reflector at the second illumination angle is shorter than that at the first illumination angle.

Abstract: An ocular optical system used to view an image displayed on an image display surface, which includes a first lens having positive refractive power, a second lens of meniscus shape having negative refractive power with its concave surface facing the image display surface side, and a third lens having positive refractive power arranged in this order from the image display surface side to a viewer side. A focal length of the first lens, a focal length of the second lens and a focal length of the entire system need to be determined suitably.

Abstract: The illumination apparatus includes a reflector unit to reflect a light flux from a light source. The reflector unit includes a first reflector and a second reflector whose relative positions are changeable to change an illumination angle. At a first illumination angle, the second reflector is disposed inside the first reflector, and the light flux from the light source is reflected by the second reflector to exit from the reflector unit. At a second illumination angle smaller than the first illumination angle, the first reflector is disposed further on a light exit side than the second reflector, and the light flux from the light source is reflected by at least one of the first and second reflectors to exit from the reflector unit. A distance between the light source and the second reflector at the second illumination angle is shorter than that at the first illumination angle.