Abstract: The present invention provides a color separation optical system which separates an entrance ray into at least three rays of a first color light, a second color light, and a third color light being different color lights and which guides the three rays respectively to solid-state image pickup elements disposed on different optical paths, the system including a first prism, a second prism, a third prism, and an absorption filter disposed between a second exit surface of the second prism and a third entrance surface of the third prism and configured to absorb the second color light. The third entrance surface of the third prism or a surface of the absorption filter facing the third entrance surface is provided with a second dichroic film which reflects the second color light and transmits the third color light.

Abstract: Provided is an image pickup apparatus comprising: a light control mirror element (ace CME) having a function of splitting an incident light flux (LF) into a first LF from reflection and a second LF from transmission and a function of switching between a semi-transmissive/semi-reflective state (s-t/s-rS) and a totally reflective state (TRS); a LF splitting unit causes first and second LFs to be emitted from first and second exit surfaces (ES), respectively; an electrochromic element (EE) switches between a state of transmitting light having a first wavelength range (WR) out of first LF (first state) and a state of transmitting light having a second WR out of first LF (second state); and a control device conducts switching control between a first mode in which LCME is in s-t/s-rS and EE is in first state and a second mode in which LCME is in TRS and EE is in second state.

Abstract: The present invention provides a color separation optical system which separates an entrance ray into at least three rays of a first color light, a second color light, and a third color light being different color lights and which guides the three rays respectively to solid-state image pickup elements disposed on different optical paths, the system including a first prism, a second prism, a third prism, and an absorption filter disposed between a second exit surface of the second prism and a third entrance surface of the third prism and configured to absorb the second color light. The third entrance surface of the third prism or a surface of the absorption filter facing the third entrance surface is provided with a second dichroic film which reflects the second color light and transmits the third color light.

Abstract: Provided is an image pickup apparatus comprising: a light control mirror element (ace CME) having a function of splitting an incident light flux (LF) into a first LF from reflection and a second LF from transmission and a function of switching between a semi-transmissive/semi-reflective state (s-t/s-rS) and a totally reflective state (TRS); a LF splitting unit causes first and second LFs to be emitted from first and second exit surfaces (ES), respectively; an electrochromic element (EE) switches between a state of transmitting light having a first wavelength range (WR) out of first LF (first state) and a state of transmitting light having a second WR out of first LF (second state); and a control device conducts switching control between a first mode in which LCME is in s-t/s-rS and EE is in first state and a second mode in which LCME is in TRS and EE is in second state.

Abstract: An image pickup apparatus, including: a filter including transmittance variable element and adjusting amount of incident light from lens; a photoelectric transducer; and guide optical system guiding the incident light from the filter to the photoelectric transducer. The guide optical system includes color separation optical system including, in order from object side, first prism having first dichroic film, second prism having second dichroic film, and third prism, to separate the incident light into red, green, and blue. The first or second dichroic film is blue reflection dichroic film. Rotational position of the transmittance variable element about optical axis is such a position that ratio of transmittance for blue to transmittance for green of marginal ray entering the blue reflection dichroic film at incident angle smaller than principal ray of axial ray to the blue reflection dichroic film is smaller than such ratio of the principal ray of axial ray.

Abstract: An image pickup apparatus includes: a lens apparatus; and a camera apparatus that can be attached and removed from the lens apparatus, wherein the camera apparatus includes: an image pickup element; and an optical element configured to be inserted and removed from an optical path, the optical element is a ND filter, and the ND it has a surface with positive refractive power. A ratio of a thickness of the optical element on an optical axis and a thickness of the optical length adjustment unit on the optical axis is appropriately set.

Abstract: Provided is a camera apparatus including a lens apparatus which is attachable thereto and detachable therefrom, the camera apparatus including: an optical system; and an optical element which is insertable to and removable from an optical path of the optical system, in which: the optical element includes a surface having positive refractive power; and the optical system includes a surface having negative refractive power.

Abstract: An image pickup apparatus, including: a filter including transmittance variable element and adjusting amount of incident light from lens; a photoelectric transducer; and guide optical system guiding the incident light from the filter to the photoelectric transducer. The guide optical system includes color separation optical system including, in order from object side, first prism having first dichroic film, second prism having second dichroic film, and third prism, to separate the incident light into red, green, and blue. The first or second dichroic film is blue reflection dichroic film. Rotational position of the transmittance variable element about optical axis is such a position that ratio of transmittance for blue to transmittance for green of marginal ray entering the blue reflection dichroic film at incident angle smaller than principal ray of axial ray to the blue reflection dichroic film is smaller than such ratio of the principal ray of axial ray.

Abstract: An image pickup apparatus includes: a lens apparatus; and a camera apparatus that can be attached and removed from the lens apparatus, wherein the camera apparatus includes: an image pickup element; and an optical element configured to be inserted and removed from an optical path, the optical element is a ND filter, and the ND it has a surface with positive refractive power. A ratio of a thickness of the optical element on an optical axis and a thickness of the optical length adjustment unit on the optical axis is appropriately set.

Abstract: Provided is a camera apparatus including a lens apparatus which is attachable thereto and detachable therefrom, the camera apparatus including: an optical system; and an optical element which is insertable to and removable from an optical path of the optical system, in which: the optical element includes a surface having positive refractive power; and the optical system includes a surface having negative refractive power.

Abstract: An image pickup optical system including: a first prism including: a first incident surface where subject beam enters; a division surface for dividing the beam from the first incident surface into image-pickup beam and focus-detection beam; and a first exit surface from which reflection beam reflected on the division surface, the image-pickup beam or the focus-detection beam, exits; and a second prism including: a second incident surface on which transmission beam passing through the division surface, the image-pickup beam or focus-detection beam, enters; and a second exit surface from which the transmission beam exits, wherein the reflection beam is reflected on the division surface, reflected on the first incident surface, and reflected on the division surface to reach the first exit surface, and satisfying 0.1<DA/DB<0.5, where DA and DB indicate beam diameters of beams toward the image pickup elements for focus detection and for image pickup.

Abstract: An image pickup optical system including: a first prism including: a first incident surface where subject beam enters; a division surface for dividing the beam from the first incident surface into image-pickup beam and focus-detection beam; and a first exit surface from which reflection beam reflected on the division surface, the image-pickup beam or the focus-detection beam, exits; and a second prism including: a second incident surface on which transmission beam passing through the division surface, the image-pickup beam or focus-detection beam, enters; and a second exit surface from which the transmission beam exits, wherein the reflection beam is reflected on the division surface, reflected on the first incident surface, and reflected on the division surface to reach the first exit surface, and satisfying 0.1<DA/DB<0.5, where DA and DB indicate beam diameters of beams toward the image pickup elements for focus detection and for image pickup.

Abstract: A free space optics communication apparatus which performs optical axis correction with high accuracy is disclosed. The free space optics communication apparatus of the present invention includes a first light receiving element and a second light receiving element, a light converging optical system which converges a light flux incident from the outside to form a spot of the light flux on each of light receiving surfaces of the first and second light receiving elements, and information producing section which combines outputs from the first and second light receiving elements to produce information on positions of the spots. The spots formed on the light receiving surfaces of the first and second light receiving elements have a point-symmetrical relationship.

Abstract: There is provided an optical detection apparatus, comprising a light-receiving element, an optical system which forms a spot of light flux on a light-receiving surface of the light-receiving element by externally incident light flux, and an information generating section which generates information with respect to a position of the spot based on the output from the light-receiving element. The optical system includes an optical element array having a plurality of optical element portions, and a plurality of spots formed by the plurality of optical element portions substantially overlap to each other on the light-receiving surface.

Abstract: An optical transmission device for providing stable communication with a partner device by reducing errors in optical axis misalignment. The errors are caused by uneven distribution of the light intensity in a received light beam resulting from atmospheric microscopic fluctuations. One embodiment includes a transmission and receiving unit, which employs two photodetectors, one aligned with and the other misaligned with the optical axis of the optical transmission device. Other embodiments employ a movable means for shifting a photodetector or a lens unit relative to the optical axis of the optical transmission device.

Abstract: An optical transmission device for providing stable communication with a partner device by reducing errors in optical axis misalignment. Such errors are caused by uneven distribution of the light intensity in a received light beam resulting from atmospheric microscopic fluctuations. A cross pattern filter having at least two cross patterns is used at a partner transmission device side with respect to an incident direction detecting means, and arranged so that a cross pattern generated on the position detecting photodetector by the cross pattern filter and parting lines for dividing a position detecting photodetector do not overlap with each other, but intersect with each other.

Abstract: A communication optical system having a compact structure and capable of preventing crosstalk is disclosed. The communication optical system includes a light source, a light-receiving element and a beam-splitting member. The beam-splitting member performs one of transmission and reflection towards an incident/emergent port, and performs one of reflection and transmission towards the light-receiving element of a second light beam from the incident/emergent port. The light source and the light-receiving element are arranged on the same side with respect to the beam-splitting member.

Abstract: A communication optical system in accordance with an aspect comprises a light source; a light-receiving element; a first and a second prisms, which are cemented to each other; and a beam-splitting member, which performs one of transmission and reflection towards an incident and emergent port, of a first light beam from the light source, and performs one of reflection and transmission towards the light-receiving element, of a second light beam from the incident and emergent port. The beam-splitting member is arranged at a cemented portion of the first prism and second prisms, and the light source and the light-receiving element are arranged on the same side with respect to the first and second prism. The second prism comprises a first surface cemented to the first prism, a second surface which is parallel to the first surface and a third surface disposed on the opposite side of the first surface with respect to the light source.

Abstract: A free space optics communication apparatus which performs optical axis correction with high accuracy is disclosed. The free space optics communication apparatus of the present invention includes a first light receiving element and a second light receiving element, a light converging optical system which converges a light flux incident from the outside to form a spot of the light flux on each of light receiving surfaces of the first and second light receiving elements, and information producing section which combines outputs from the first and second light receiving elements to produce information on positions of the spots. The spots formed on the light receiving surfaces of the first and second light receiving elements have a point-symmetrical relationship.

Abstract: There is provided an optical detection apparatus, comprising a light-receiving element, an optical system which forms a spot of light flux on a light-receiving surface of the light-receiving element by externally incident light flux, and an information generating section which generates information with respect to a position of the spot based on the output from the light-receiving element. The optical system includes an optical element array having a plurality of optical element portions, and a plurality of spots formed by the plurality of optical element portions substantially overlap to each other on the light-receiving surface.