Abstract: An optical element including: a container which is light-transmissive at least in a light passage region; a light-transmissive dispersion medium enclosed in the container; a light-transmissive dispersion dispersed in the dispersion medium and having a refractive index different from the refractive index of the dispersion medium; and an electromagnetic field generator which controls the refraction of light passing through the light passage region by moving the dispersion dispersed in the dispersion medium by an electromagnetic force.

Abstract: An optical unit capable of freely changing the refractive power and operating with a reduced deterioration in performance, an image taking apparatus having an image taking lens using the optical unit, and an optical finder using the optical unit. The optical unit includes a lens body having an electromagnetic field generator which changes the focal length of the lens body by moving, by an electromagnetic force, a dispersoid which is dispersed in a light-transmissive dispersion medium enclosed in a container, which is light-transmissive, and which has a refractive index different from the refractive index of the dispersion medium. The optical unit also includes a focal length changing section which changes the focal length of the lens body in three steps by controlling an electromagnetic field generated by the electromagnetic field generator.

Abstract: The present invention provides a variable-focus lens capable of freely changing the refractive power and operating with a reduced deterioration in performance and an image taking apparatus having a focal-length-variable image taking lens including the variable-focus lens. The variable-focus lens includes: a lens body having an electromagnetic field generator which changes the focal length of the light passage region by moving, by an electromagnetic force, light-transmissive nanoparticles which are dispersed in a light-transmissive dispersion medium enclosed in a container having the shape of a lens, and which have a refractive index different from the refractive index of the dispersion medium; a moving mechanism which moves the lens body in an optical axis direction; and a focal length adjustment section which changes the focal length of the lens body by controlling an electromagnetic field generated by the electromagnetic field generator.

Abstract: The present invention provides a light emitting unit that can accurately control the light output angle and/or direction over long period and an image taking apparatus provided with the light emitting unit. The light emitting unit has a light source, a reflector provided at the back surface of the light source and an optical member provided at the front of the light source. The optical member having: a container which is light-transmissive at least in a light passage region; a light-transmissive dispersion medium enclosed in the container; a dispersoid which is dispersed in the dispersion medium, which is light-transmissive, and which has a refractive index different from the refractive index of the dispersion medium. The optical member controls the output angle and/or direction of the light emitted from the light source and reflected by the reflector by moving the dispersoid using electromagnetic force.

Abstract: The present invention provides a light emitting unit that can accurately control the light output angle and/or direction over long period and an image taking apparatus provided with the light emitting unit. The light emitting unit has a light source, a reflector provided at the back surface of the light source and an optical member provided at the front of the light source. The optical member having: a container which is light-transmissive at least in a light passage region; a light-transmissive dispersion medium enclosed in the container; a dispersoid which is dispersed in the dispersion medium, which is light-transmissive, and which has a refractive index different from the refractive index of the dispersion medium. The optical member controls the output angle and/or direction of the light emitted from the light source and reflected by the reflector by moving the dispersoid using electromagnetic force.

Abstract: The present invention provides a variable-focus lens capable of freely changing the refractive power and operating with a reduced deterioration in performance and an image taking apparatus having a focal-length-variable image taking lens including the variable-focus lens. The variable-focus lens includes: a lens body having an electromagnetic field generator which changes the focal length of the light passage region by moving, by an electromagnetic force, light-transmissive nanoparticles which are dispersed in a light-transmissive dispersion medium enclosed in a container having the shape of a lens, and which have a refractive index different from the refractive index of the dispersion medium; a moving mechanism which moves the lens body in an optical axis direction; and a focal length adjustment section which changes the focal length of the lens body by controlling an electromagnetic field generated by the electromagnetic field generator.

Abstract: An optical unit capable of freely changing the refractive power and operating with a reduced deterioration in performance, an image taking apparatus having an image taking lens using the optical unit, and an optical finder using the optical unit. The optical unit includes a lens body having an electromagnetic field generator which changes the focal length of the lens body by moving, by an electromagnetic force, a dispersoid which is dispersed in a light-transmissive dispersion medium enclosed in a container, which is light-transmissive, and which has a refractive index different from the refractive index of the dispersion medium. The optical unit also includes a focal length changing section which changes the focal length of the lens body in three steps by controlling an electromagnetic field generated by the electromagnetic field generator.

Abstract: An optical element including: a container which is light-transmissive at least in a light passage region; a light-transmissive dispersion medium enclosed in the container; a light-transmissive dispersoid dispersed in the dispersion medium and having a refractive index different from the refractive index of the dispersion medium; and an electromagnetic field generator which controls the refraction of light passing through the light passage region by moving the dispersoid dispersed in the dispersion medium by an electromagnetic force.