Abstract: An image capturing unit comprises a variable optical element, an optical unit, and a light-flux limiting section. The variable optical element includes a first liquid member, a second liquid member, and a container which contains the first liquid member and the second liquid member. An interfacial shape between the first liquid member and the second liquid member varies according to a voltage which is applied to the liquid members.

Abstract: A variable optical element is formed by a first liquid member, a second liquid member which is unsoluble in the first liquid member, a container which contains the first liquid member and the second liquid member, an index for positioning the variable optical element according to a predetermined reference. In the variable optical element, an interfacial shape between the first liquid and the second liquid surface varies according to a voltage which is applied to the liquid members, and the index is disposed such that a wave front aberration in the variable optical element should be minimum or fewer than a predetermined value under condition that the variable optical element is positioned according to the predetermined reference. By doing this, it is possible to restrict the wave front aberration which is caused by a gravity in the variable optical element, the optical unit, and the image capturing device.

Abstract: An image display element 1 and an observation optical system 2 which forms an exit pupil 4 for observation of an image displayed on the image display element are included, wherein the observation optical system 2 has at least one surface 21 that has a lens function, and the following condition (1) is satisfied:

Abstract: The imaging apparatus comprises plural optical systems having different focal length from that of an imaging element, a transmittance variable element and a reflective optical element, It is constituted so that the focal length is changed by controlling transmittance of the transmittance variable element. Thus, a compact structured and small sized multi-focus imaging apparatus can be provided.

Abstract: The object of the invention is to make a viewing unit of the image display compact so that it can be mounted on portable telephones or information terminals. The portable image display of the invention comprises a speaker portion, a microphone portion, an image display device 9 and a viewing optical system for forming an exit pupil to view an image displayed on the image display device and having a generally positive refracting power. The viewing optical system is constructed of at least one prism member 10 comprising an entrance surface through which a light beam emanating from the image display device 9 is entered into the prism, at least one reflecting surface at which the light beam is reflected within the prism and an exit surface through which the light beam leaves the prism. The at least one reflecting surface has a curved surface shape for imparting power to a light beam.

Abstract: The invention provides an optical apparatus enabling diopter adjustment, etc. to be achieved using, for instance, a reflection type variable-optical property optical element or a variable-optical property mirror but without recourse to any mechanical moving part. The variable-optical property mirror 9 comprises an aluminum-coated thin film 9a and a plurality of electrodes 9b. Via variable resistors 11 and a power source switch 13 a power source 12 is connected between the thin film 9a and the electrodes 9b, so that the resistance values of the variable resistors 11 can be controlled by an operating unit 14. The shape of the thin film 9a as a reflecting surface is controlled by changing the resistance value of each variable resistor 11 in response to a signal from the operating unit 14 in such a manner that the imaging capability of the variable mirror is optimized.

Abstract: An image display element 1 and an observation optical system 2 which forms an exit pupil 4 for observation of an image displayed on the image display element are included, wherein the observation optical system 2 has at least one surface 21 that has a lens function, and the following condition (1) is satisfied: 0.1<P·PD·ZD<5  (1) where P is a pixel pitch (in &mgr;m) of the image display element, PD is a diameter (in mm) of the exit pupil, and ZD is a distance (in mm) from the display surface of the image display element to the first surface having a lens function. Whereby, weight reduction is achieved while good image quality is maintained regarding an image display apparatus that is used for magnifying observation of an image on a display element.

Abstract: An objective lens system consisting of a first lens unit having a negative refractive power and a second lens unit having a positive refractive power wherein the first lens unit or the second lens unit comprises at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis. This objective lens system favorably corrects chromatic aberration and other aberrations by adequately selecting a value expressing an Abbe's number and a refractive power of medium for the radial type gradient index lens element.

Abstract: The invention provides an optical apparatus enabling diopter adjustment, etc. to be achieved using, for instance, a reflection type variable-optical property optical element or a variable-optical property mirror but without recourse to any mechanical moving part. The variable-optical property mirror 9 comprises an aluminum-coated thin film 9a and a plurality of electrodes 9b. Via variable resistors 11 and a power source switch 13 a power source 12 is connected between the thin film 9a and the electrodes 9b, so that the resistance values of the variable resistors 11 can be controlled by an operating unit 14. The shape of the thin film 9a as a reflecting surface is controlled by changing the resistance value of each variable resistor 11 in response to a signal from the operating unit 14 in such a manner that the imaging capability of the variable mirror is optimized.

Abstract: A portable TV telephone has an objective lens system configured to form an image of an object and an antenna configured to transmit and receive at least one of an image signal representing the image of the object, a dial signal and a voice signal carried by radio waves. A display unit is configured to display at least a dial number and the image of the object and a switch is configured to operate responsive to at least the dial number. The objective lens system includes a diffractive optical element configured to at least correct chromatic aberration produced by the objective lens system. The objective lens system includes, in order from an object side, a first negative lens unit and a second positive lens unit.

Abstract: The invention provides an optical apparatus enabling diopter adjustment, etc. to be achieved using, for instance, a reflection type variable-optical property optical element or a variable-optical property mirror but without recourse to any mechanical moving part. The variable-optical property mirror 9 comprises an aluminum-coated thin film 9a and a plurality of electrodes 9b. Via variable resistors 11 and a power source switch 13 a power source 12 is connected between the thin film 9a and the electrodes 9b, so that the resistance values of the variable resistors 11 can be controlled by an operating unit 14. The shape of the thin film 9a as a reflecting surface is controlled by changing the resistance value of each variable resistor 11 in response to a signal from the operating unit 14 in such a manner that the imaging capability of the variable mirror is optimized.

Abstract: An image display element 1 and an observation optical system 2 which forms an exit pupil 4 for observation of an image displayed on the image display element are included, wherein the observation optical system 2 has at least one surface 21 that has a lens function, and the following condition (1) is satisfied:

Abstract: The object of the invention is to make a viewing unit of the image display compact so that it can be mounted on portable telephones or information terminals. The portable image display of the invention comprises a speaker portion, a microphone portion, an image display device 9 and a viewing optical system for forming an exit pupil to view an image displayed on the image display device and having a generally positive refracting power. The viewing optical system is constructed of at least one prism member 10 comprising an entrance surface through which a light beam emanating from the image display device 9 is entered into the prism, at least one reflecting surface at which the light beam is reflected within the prism and an exit surface through which the light beam leaves the prism. The at least one reflecting surface has a curved surface shape for imparting power to a light beam.

Abstract: An objective lens system consisting of a first lens unit having a negative refractive power and a second lens unit having a positive refractive power wherein the first lens unit or the second lens unit comprises at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis. This objective lens system favorably corrects chromatic aberration and other aberrations by adequately selecting a value expressing an Abbe's number and a refractive power of medium for the radial type gradient index lens element.

Abstract: A zoom optical system provides a series of lens units designed to allow for zooming with minimal change in aberration resulting from the movement of the lens units. Each lens unit has a plurality of lens units. One embodiment has, in order from the object side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a positive refractive power and a fourth lens unit having a positive refractive power wherein the second lens unit may have at least one gradient index lens element and the first lens unit is kept stationary during a change of magnification. Additional embodiments have more or fewer lens units and the refractive power of each lens unit is varied. In some embodiments, a lens unit other than the first lens unit is kept stationary.

Abstract: An objective optical system is disclosed having, in a first construction, in relative order from the object side, a first lens element of negative refractive power, a visual field conversion optical element which folds light rays incident thereon, a stop, and either one or two additional lens elements of positive refractive power which form an objective optical system. Certain prescribed conditions are satisfied in order that the objective optical system be compact and have acceptably small aberrations to thereby enable a high quality image to be formed. In a second alternative construction, the stop is positioned after the second lens element and the third lens element includes a convex surface on the image side and satisfies a prescribed condition.

Abstract: An objective optical system comprising, in order from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power and a third lens unit having a positive refractive power, wherein the second lens unit is moved along an optical axis for changing a magnification. This objective optical system is configured to be compact and have favorable optical performance by adequately selecting an airspace between the first lens unit and the second lens unit as well as a power for the first lens unit.

Abstract: A portable TV telephone includes an objective lens system. The objective lens system is configured to form an image of an object. An antenna is configured to transmit and receive at least one of said image of the object, a dial number and a voice carried by radio waves. A display is configured to display at least one of the image of the object and the dial number. The objective lens system includes a first negative lens unit and a second positive lens unit in order from an object side. An aperture stop is disposed between the first lens unit and said second lens unit. In one embodiment, the first lens and the second lens each have a lens barrel configured to position the respective lens units such that circumferences of the lens units contact interior walls of the portable TV telephone. In another embodiment, the first lens unit and the second lens unit are cemented at outer circumferential portions outside an effective diameter through which rays transmit.

Abstract: A zoom optical system provides a series of lens units designed to allow for zooming with minimal change in aberration resulting from the movement of the lens units. Each lens unit has a plurality of lens units. One embodiment has, in order from the object side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a positive refractive power and a fourth lens unit having a positive refractive power wherein the second lens unit has at least one gradient index lens element and the first lens unit is kept stationary during a change of magnification. Additional embodiments have more or fewer lens units and the refractive power of each lens unit is varied. In some embodiments, a lens unit other than the first lens unit is kept stationary.

Abstract: A zoom optical system is disclosed. The zoom optical system provides a series of lens units designed to allow for zooming with minimal change in aberration resulting from the movement of the lens units. To achieve this goal each lens unit is has a plurality of lens units. By way of example, one embodiment of the present invention has, in order from the object side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a positive refractive power and a fourth lens unit having a positive refractive power wherein the second lens unit comprises at least one gradient index lens element and the first lens unit is kept stationary during a change of magnification. Additional embodiments are described in which more or fewer lens units are used and the refractive power of each lens unit is varied. In some embodiments, a lens unit other than the first lens unit is kept stationary.