Abstract: An audio output device includes PWM output devices, a weighting unit, a mixer, and an amplifier. The PWM output devices divide audio data into multiple parts including an upper bit part to a lower bit part, and output the multiple parts of the audio data as PWM outputs. The weighting unit weights the PWM outputs from the PWM output devices. The mixer synthesizes the PWM outputs after being weighted. The amplifier supplies an electric current to a sounding body in accordance with a synthesis result by the mixer to cause the sounding body to emit a sound.

Abstract: An objective optical system for an endoscope forms an intermediate image at a position conjugate to an object surface, forms the intermediate image on an imaging plane again, and includes an aperture stop that is provided between the intermediate image and the imaging plane. Conditional expression (1) is satisfied in a case in which a distance between a lens surface closest to an object and a paraxial entrance pupil position on an optical axis is denoted by FS and a focal length of the entire system is denoted by f, |FS/f|<0.

Abstract: The projection display device includes an imaging element, a light valve, and an image-forming optical system that projects an optical image according to light emitted from the light valve onto a magnification side imaging surface and forms an image of light incident from a magnification side on an imaging element. The image-forming optical system includes a first optical system that comprises at least one lens and is used in common in projection and imaging, and a separation member that separates an optical path from the light valve toward the first optical system from an optical path from the first optical system toward the imaging element. An antireflection layer is comprised in at least one of antireflection target surfaces having a significant influence of ghost light.

Abstract: A projection display device of a front projection type includes a light valve that modulates light based on image data and emits the light and an image forming optical system that projects an optical image of the light modulated by the light valve onto a projection surface, in which the image forming optical system includes a first optical system that includes at least one lens and a first reflection member that reflects the light emitted from the light valve toward the first optical system, the first optical system and the first reflection member are configured to be rotatable in a pitch direction, and the first reflection member rotates by a pitch angle ?/2 in conjunction with rotation of the first optical system by a pitch angle ?.

Abstract: A projection display device includes an imaging element, a light source, a light valve that modulates light from the light source and emits modulated light, and an imaging optical system. The imaging optical system includes a first optical system that is used in common in projection and imaging, a second optical system that is used only in projection, a third optical system that is used only in imaging, and a separation member that separates an optical path from the second optical system toward the first optical system from an optical path from the first optical system toward the third optical system. The third optical system includes a first light shielding member that is arranged in the vicinity of a stop position of the third optical system and shields a part of a luminous flux.

Abstract: A projection display device includes an imaging element, a light source, a light valve that modulates light from the light source and emits modulated light in a prescribed polarization state, and an imaging optical system. The imaging optical system includes a first optical system that is used in common in projection and imaging, a second optical system that is used only in projection, a third optical system that is used only in imaging, and a separation member that separates an optical path from the second optical system toward the first optical system from an optical path from the first optical system toward the third optical system. The first optical system comprises a quarter wave plate and a polarizer arranged in a state of transmitting the light emitted from the light valve.

Abstract: An objective optical system for an endoscope forms an intermediate image at a position conjugate to an object surface and forms the intermediate image on an imaging plane again, and is adapted to satisfy Conditional expressions (1) to (3) in a case in which a maximum effective image height on the imaging plane is denoted by HI, a focal length of the entire system is denoted by f, an effective luminous flux diameter on a lens surface closest to an object is denoted by FD, an F-Number of the entire system is denoted by FNo, and a paraxial relay magnification of the intermediate image on the imaging plane is denoted by R. 0.7<HI/|f|??(1) FD×FNo/|f|6??(2) ?2<?R<?0.8??(3).

Abstract: An optical unit includes: a projection optical system on which light from a display unit is incident; a common optical system that projects light passing through the projection optical system to a projection target object and forms an image of a subject at a side of the projection target object; an optical member for guiding light passing through the projection optical system to the common optical system and guiding an intermediate image formed by at least a part of the common optical system to an imaging element; and an imaging optical system for forming the intermediate image on the imaging element, and an image forming position of the intermediate image is present between a component closest to a side of the projection target object among components constituting the common optical system and the optical member.

Abstract: An objective optical system for an endoscope forms an intermediate image at a position conjugate to an object surface and forms the intermediate image on an imaging plane again, and is adapted to satisfy Conditional expressions (1) to (3) in a case in which a maximum effective image height on the imaging plane is denoted by HI, a focal length of the entire system is denoted by f, an effective luminous flux diameter on a lens surface closest to an object is denoted by FD, a maximum effective luminous flux diameter among effective luminous flux diameters on lens surfaces of the entire system is denoted by BD, and a paraxial relay magnification of the intermediate image on the imaging plane is denoted by ?R. 0.7<HI|f|??(1) FD/BD<0.5??(2) ?2<?R<?0.

Abstract: The projection display device includes an imaging element, a light valve, and an image-forming optical system that projects an optical image according to light emitted from the light valve onto a magnification side imaging surface and forms an image of light incident from a magnification side on an imaging element. The image-forming optical system includes a first optical system that comprises at least one lens and is used in common in projection and imaging, and a separation member that separates an optical path from the light valve toward the first optical system from an optical path from the first optical system toward the imaging element. An antireflection layer is comprised in at least one of antireflection target surfaces having a significant influence of ghost light.

Abstract: A projection display device includes an imaging element, a light source, a light valve that modulates light from the light source and emits modulated light, and an imaging optical system. The imaging optical system includes a first optical system that is used in common in projection and imaging, a second optical system that is used only in projection, a third optical system that is used only in imaging, and a separation member that separates an optical path from the second optical system toward the first optical system from an optical path from the first optical system toward the third optical system. The third optical system includes a first light shielding member that is arranged in the vicinity of a stop position of the third optical system and shields a part of a luminous flux.

Abstract: A projection display device includes an imaging element, a light source, a light valve that modulates light from the light source and emits modulated light in a prescribed polarization state, and an imaging optical system. The imaging optical system includes a first optical system that is used in common in projection and imaging, a second optical system that is used only in projection, a third optical system that is used only in imaging, and a separation member that separates an optical path from the second optical system toward the first optical system from an optical path from the first optical system toward the third optical system. The first optical system comprises a quarter wave plate and a polarizer arranged in a state of transmitting the light emitted from the light valve.

Abstract: The number of lenses within an objective lens for endoscopes is only three. The objective lens for endoscopes includes, in order from the object side, a first lens which is a single lens having a negative refractive power and a concave surface toward the object side, an aperture stop, and a cemented lens. The cemented lens is formed by cementing one positive lens and one negative lens together. Conditional formulae related to the distance from the surface toward the object side of the first lens to the aperture stop and the Abbe's numbers of the positive lens and the negative lens that constitute the cemented lens are satisfied.

Abstract: There is provided a head-up display device that reflects and enlarges an image, which is displayed on an image display element, by a curved mirror, allows an observer to visually recognize the image as a virtual image, can change a virtual image display position, and is small. A head-up display device, which reflects and enlarges a displayed primary display image by a curved mirror and allows an observer to visually recognize the primary display image as a virtual image, includes a virtual-image-position change portion of changing a distance between the observer and the virtual image and a display-size change portion of changing the display size of the primary display image, and is adapted to satisfy the following conditional expression (1). 2.5<(Hf/Hn)/(Bf/Bn)<15.

Abstract: A vehicle approach notification device includes a speaker disposed between push-pull circuits. The push-pull circuits amplify power of a notification sound signal by their push-pull outputs, and output the amplified notification sound signal to the speaker so that the speaker emits a notification sound for notification of an approach of a vehicle. When the push-pull outputs of the push-pull circuits are stopped, and the microcomputer outputs a high-level signal between a common connection terminal and ground, the microcomputer determines that there is a wire-discontinuity failure in the speaker when a voltage between common connection terminals is equal to or higher than a predetermined value.

Abstract: An objective optical system for an endoscope forms an intermediate image at a position conjugate to an object surface, forms the intermediate image on an imaging plane again, and includes an aperture stop that is provided between the intermediate image and the imaging plane. Conditional expression (1) is satisfied in a case in which a distance between a lens surface closest to an object and a paraxial entrance pupil position on an optical axis is denoted by FS and a focal length of the entire system is denoted by f. |FS/f|<0.

Abstract: An objective optical system for an endoscope forms an intermediate image at a position conjugate to an object surface and forms the intermediate image on an imaging plane again, and is adapted to satisfy Conditional expressions (1) to (3) in a case in which a maximum effective image height on the imaging plane is denoted by HI, a focal length of the entire system is denoted by f, an effective luminous flux diameter on a lens surface closest to an object is denoted by FD, an F-Number of the entire system is denoted by FNo, and a paraxial relay magnification of the intermediate image on the imaging plane is denoted by R. 0.7<HI/|f|??(1) FD×FNo/|f|6 ??(2) ?2<?R<?0.

Abstract: An objective optical system for an endoscope forms an intermediate image at a position conjugate to an object surface and forms the intermediate image on an imaging plane again, and is adapted to satisfy Conditional expressions (1) to (3) in a case in which a maximum effective image height on the imaging plane is denoted by HI, a focal length of the entire system is denoted by f, an effective luminous flux diameter on a lens surface closest to an object is denoted by FD, a maximum effective luminous flux diameter among effective luminous flux diameters on lens surfaces of the entire system is denoted by BD, and a paraxial relay magnification of the intermediate image on the imaging plane is denoted by ?R. 0.7<HI|f|??(1) FD/BD<0.5 ??(2) ?2<?R<?0.

Abstract: A vehicle approach notification device includes a speaker disposed between push-pull circuits. The push-pull circuits amplify power of a notification sound signal by their push-pull outputs, and output the amplified notification sound signal to the speaker so that the speaker emits a notification sound for notification of an approach of a vehicle. When the push-pull outputs of the push-pull circuits are stopped, and the microcomputer outputs a high-level signal between a common connection terminal and ground, the microcomputer determines that there is a wire-discontinuity failure in the speaker when a voltage between common connection terminals is equal to or higher than a predetermined value.

Abstract: A distance measurement device includes a detection unit, an optical path forming unit, a common reduction unit that reduces influence of variation of an optical axis of an image formation optical system, and reduces variation of an optical axis of the directional light, an auxiliary reduction unit that auxiliarily reduces at least one of influence of variation of the optical axis of the image formation optical system or variation of the optical axis of the directional light, and a control unit that, in a case of operating the common reduction unit and the auxiliary reduction unit at the same time, controls the common reduction unit and the auxiliary reduction unit to reduce variation of an irradiation position of the directional light in a subject image received as light by a light receiving section.