Abstract: An image display apparatus of head mounted type includes first and second liquid crystal display panels for displaying first and second images to be observed by right and left eyes, respectively of a user wearing the image display apparatus, an optical system for forming virtual images of the displayed first and second images such that the virtual images can be seen by the user, a controller for controlling electronically at least one of position, posture, size and shape of the first and second displayed images. The first and second images are smaller than display areas of the first and second liquid crystal display panels. In one embodiment, the controller includes a button for moving horizontally and vertically the displayed images on the display panels and a button for rotating the displayed images.

Abstract: A head-mounted see-through display which enables an outside image and an electronic image to be selectively observed by making a liquid crystal shutter transparent or opaque. To eliminate the problem that during the observation of the electronic image the outside image is undesirably seen through the peripheral region of the electronic image, display light from a two-dimensional display device (11) is first transmitted by a half-mirror (12), and the transmitted light is reflected by a concave mirror (13). Then, the reflected light is reflected by the half-mirror (12) so as to be led to the observer's eye as an enlarged image. To prevent the outside light from entering the eye through the half-mirror (12) during the observation of the electronic image, a negative or positive type TN or STN liquid crystal shutter (10) is disposed in front of the half-mirror (12).

Abstract: The measuring endoscope includes a device for producing interference fringes, a device for projecting the interference fringes onto a surface of an object to be measured, a device for scanning the interference fringes, an imaging device for reading vibrations of brightness on the surface of the object to be measured which are caused by the scanning of the interference fringes and a processing device capable of determining depths of concavities and heights of convexities on the surface the measured object by calculating data output from the imaging device. This measuring endoscope makes it possible to determine accurately the location of internal diseases within organs of human bodies, defects in gas pipes and so on.

Abstract: An interference microscope includes a light source, a member for splitting up light from the light source into two components, a member for recombining the two components emerging from a sample, a polarizing plate whose transmission axis is oriented at a predetermined angle with directions of polarization of the two components, and an imaging element for detecting the light transmitted through the polarizing plate. This interference microscope is provided with a member for changing the state of polarization on an optical path from the light source to the splitting member, or an optical path from the recombining member to the imaging element. Thus, the interference microscope allows the setting and adjustment of contrast to be easily performed without affecting an imaging relationship.