Abstract: A superior reflex type vertically-aligned liquid crystal display device wherein the refractive index anisotropy ?n of its liquid crystal material is controlled to be more than 0.1, and the transmissivity of the liquid crystal is saturated with facility at a low voltage below 6V despite a reduction of the thickness of the vertically-aligned liquid crystal layer to less than 2 ?m, hence achieving satisfactory driving at a practically low voltage while attaining another advantage of remarkable improvement in the transmissivity itself. Therefore, the display device indicates a sufficient transmissivity, an excellent low-voltage driving characteristic and a fast response. Further improvements are realizable in a display apparatus, a projection optical system and a projection display system by the use of such display device.

Abstract: A superior reflex type vertically-aligned liquid crystal display device wherein the refractive index anisotropy ?n of its liquid crystal material is controlled to be more than 0.1, and the transmissivity of the liquid crystal is saturated with facility at a low voltage below 5 to 6V despite a reduction of the thickness of the vertically-aligned liquid crystal layer to less than 2 ?m, hence achieving satisfactory driving at a practically low voltage while attaining another advantage of remarkable improvement in the transmissivity itself. Therefore, the display device indicates a sufficient transmissivity, an excellent low-voltage driving characteristic and a fast response. Further improvements are realizable in a display apparatus, a projection optical system and a projection display system by the use of such display device.

Abstract: A superior reflex type vertically-aligned liquid crystal display device wherein the refractive index anisotropy ?n of its liquid crystal material is controlled to be more than 0.1, and the transmissivity of the liquid crystal is saturated with facility at a low voltage below 5 to 6V despite a reduction of the thickness of the vertically-aligned liquid crystal layer to less than 2 ?m, hence achieving satisfactory driving at a practically low voltage while attaining another advantage of remarkable improvement in the transmissivity itself. Therefore, the display device indicates a sufficient transmissivity, an excellent low-voltage driving characteristic and a fast response. Further improvements are realizable in a display apparatus, a projection optical system and a projection display system by the use of such display device.

Abstract: A superior reflex type vertically-aligned liquid crystal display device wherein the refractive index anisotropy ?n of its liquid crystal material is controlled to be more than 0.1, and the transmissivity of the liquid crystal is saturated with facility at a low voltage below 5 to 6V despite a reduction of the thickness of the vertically-aligned liquid crystal layer to 2.5 ?m or less, hence achieving satisfactory driving at a practically low voltage while attaining another advantage of remarkable improvement in the transmissivity itself. Therefore, the display device indicates a sufficient transmissivity, an excellent low-voltage driving characteristic and a fast response. Further improvements are realizable in a display apparatus, a projection optical system and a projection display system by the use of such display device.

Abstract: A superior reflex type vertically-aligned liquid crystal display device wherein the refractive index anisotropy &Dgr;n of its liquid crystal material is controlled to be more than 0.1, and the transmissivity of the liquid crystal is saturated with facility at a low voltage below 5 to 6V despite a reduction of the thickness of the vertically-aligned liquid crystal layer to 2.5 &mgr;m or less, hence achieving satisfactory driving at a practically low voltage while attaining another advantage of remarkable improvement in the transmissivity itself. Therefore, the display device indicates a sufficient transmissivity, an excellent low-voltage driving characteristic and a fast response. Further improvements are realizable in a display apparatus, a projection optical system and a projection display system by the use of such display device.

Abstract: A superior reflex type vertically-aligned liquid crystal display device wherein the refractive index anisotropy &Dgr;n of its liquid crystal material is controlled to be more than 0.1, and the transmissivity of the liquid crystal is saturated with facility at a low voltage below 5 to 6V despite a reduction of the thickness of the vertically-aligned liquid crystal layer to less than 2 &mgr;m, hence achieving satisfactory driving at a practically low voltage while attaining another advantage of remarkable improvement in the transmissivity itself. Therefore, the display device indicates a sufficient transmissivity, an excellent low-voltage driving characteristic and a fast response. Further improvements are realizable in a display apparatus, a projection optical system and a projection display system by the use of such display device.

Abstract: A second harmonic generating element radiates a laser beam having a wavelength of 532 nm onto a substrate surface. The laser beam corresponds to the second harmonic beam of a fundamental laser beam having a wavelength of 1064 nm. An emitting optical system emits the laser beam vertically to the substrate surface so that the laser beam is made linear. An observing means has a optical axis Lo oriented in a different direction from a optical axis Li of the emitting optical system and provides a CCD image sensor served as a two-dimensional imaging device located in conjugation with the height or thickness of the substrate surface. The observing means operates to observe a light section image formed by the linear beam fired by the emitting optical system onto the substrate surface. Then, an image processing means precisely measures the form of the surface of an object to be measured as suppressing degrade of an S/N ratio, on the basis of the image data of the light section image observed by the observing means.

Abstract: A head-up display includes a projector which projects an image light and a hologram lens which diffracts and reflects the projected image and form a virtual image located ahead of a windshield. The hologram lens has a vertical diffraction characteristic which is equivalent to a hyperbolic or parabolic-curve mirror along a line formed by the intersection of the hologram lens and a vertical plane which includes an axis of the image light and a horizontal diffraction characteristic which is equivalent to a parabolic or elliptic curve mirror along a line which is formed by the intersection of the hologram lens and a horizontal plane which includes the axis of the image light. When the hologram is directly attached on a curved windshield which has a focal length fs (in case it is a mirror), the focal length fo of the hologram and the former focal length fs has the following relationship; 1/fo=1/fh+1/fs, where fh is a focal point when the hologram is flat.

Abstract: A manufacturing method for a hologram which can control the formation of a ghost hologram due to a surface reflected light caused on an interface with the atmosphere is disclosed. In the first manufacturing method for a hologram by a two-beam method or a one-beam method, on an interface between a substrate having a hologram photosensitive layer and the atmosphere is disposed a quarter-wave plate, and an incident light is converted from a circularly polarized light to a P-polarized light (or an S-polarized light) through the quarter-wave plate. On the other hand, in the second manufacturing method for a hologram, a substrate, which has a hologram photosensitive layer, is fittingly held by prisms on both sides thereof. A reference light is a P-polarized light, and an angle of the reference light to a surface reflected light on an interface of the reference light is set to be approximate to a right angle.