Abstract: A projection type display apparatus includes: a reflection type light valve; a polarization beam splitter that emits light obtained through polarization split executed thereat on light from a light source toward the reflection type light valve, analyzes light modulated at the reflection type light valve and includes a light blocking portion disposed near an outer edge of an exit surface through which the analyzed light exits; and a projection lens through which the analyzed light is projected.

Abstract: A cross dichroic prism color-synthesizes a plurality of color lights having entered therein separately and emits color-synthesized light to a projection lens. The cross dichroic prism includes a first dichroic film; and a second dichroic film intersecting the first dichroic film so as to pass through the first dichroic film. The cross dichroic prism is configured so that a color light having entered the cross dichroic prism and having become diffracted at a gap created in the first dichroic film over an area where the second dichroic film passes through the first dichroic film is not projected through the projection lens.

Abstract: A cross dichroic prism color-synthesizes a plurality of color lights having entered therein separately and emits color-synthesized light to a projection lens. The cross dichroic prism includes a first dichroic film; and a second dichroic film intersecting the first dichroic film so as to pass through the first dichroic film. The cross dichroicprism is configured so that a color light having entered the cross dichroic prism and having become diffracted at a gap created in the first dichroic film over an area where the second dichroic film passes through the first dichroic film is not projected through the projection lens.

Abstract: A projection type display apparatus includes a color separation optical system separating light emitted from a light source into first, second and third color light; reflection type light valves provided each in correspondence to one of the first through third color light; polarization beam splitters provided each in correspondence to one of the first through third color light, which executes polarization separation causing the first through third color light to enter the reflection type light valves, and analyzing light exiting from the reflection type light valves after being modulated; a color composition optical system having a first, a second and a third prism, wherein the analyzed first through third color light undergo color composition; and a projection lens projecting the resulting light from the color composition, and lengths of optical paths wherein each of the first through third color light travels are equal to one another.

Abstract: In a projection display apparatus that analyzes to pick up lights emitted from a plurality of the reflective light valves, color-composes the analyzed lights and projects the color-composed light, a dichroic film is disposed in at least one of optical paths of the respective color lights between the polarizing beam splitters and the dichroic prism. The dichroic film reflects such a component of a color light derived from the composite light incident on the projection optical system that has been reflected by a surface of a lens element constituting the projection optical system and incident on the dichroic prism after passing through a quarter wave phase plate and reflected or transmitted by the dichroic film within the dichroic prism to travel along the optical path of the color light in the reverse direction, thereby deflecting the color light component out of the optical path.

Abstract: A projection display apparatus in which a light emitted from a reflective light valve is made incident on a prism member and a light having passed through the prism member is projected by a projection lens, comprises a dust proofing cover that provides a seal between an emergence surface of the reflective light valve and an incidence surface of the prism member.

Abstract: A projection type display apparatus includes: a reflection type light valve; a polarization beam splitter that emits light obtained through polarization split executed thereat on light from a light source toward the reflection type light valve, analyzes light modulated at the reflection type light valve and includes a light blocking portion disposed near an outer edge of an exit surface through which the analyzed light exits; and a projection lens through which the analyzed light is projected.

Abstract: a projection type display apparatus includes: a color separation optical system that executes color separation to separate light source light emitted from a light source into first color light, second color light and third color light; reflection type light valves provided each in correspondence to one of the first color light through the third color light; polarization beam splitters provided each in correspondence to one of the first color light through the third color light, which execute polarization separation of the first color light, the second color light and the third color light resulting from the color separation, cause the first color light, the second color light and the third color light to enter the reflection type light valves and analyze light exiting the reflection type light valves after being modulated at the reflection type light valves; a color composition optical system having a first prism, a second prism and a third prism in which the analyzed first color light, the analyzed second co

Abstract: A projection type display device includes: a color separation optical system which separates light from a light source into light beams of a plurality of colors; and a plurality of polarization beam splitters, one being provided for each of the light beams of the plurality of colors which have been separated by the color separation optical system.

Abstract: A projection display apparatus in which a light emitted from a reflective light valve is made incident on a prism member and a light having passed through the prism member is projected by a projection lens, comprises a dust proofing cover that provides a seal between an emergence surface of the reflective light valve and an incidence surface of the prism member.

Abstract: In a projection display apparatus that analyzes to pick up lights emitted from a plurality of the reflective light valves, color-composes the analyzed lights and projects the color-composed light, a dichroic film is disposed in at least one of optical paths of the respective color lights between the polarizing beam splitters and the dichroic prism. The dichroic film reflects such a component of a color light derived from the composite light incident on the projection optical system that has been reflected by a surface of a lens element constituting the projection optical system and incident on the dichroic prism after passing through a quarter wave phase plate and reflected or transmitted by the dichroic film within the dichroic prism to travel along the optical path of the color light in the reverse direction, thereby deflecting the color light component out of the optical path.

Abstract: An analyzing-synthesizing optical system has the structure in which for each of the three primary colors of R, G, and B, there are provided a light valve for modulating incident light and a polarization beam splitter for guiding specific polarized light to this light valve and extracting only modulated light coming from the light valve to output it, wherein these light valves and polarization beam splitters are fixed as integrated with a synthesizing optical system comprising a cross dichroic prism and wherein optical path lengths of optical paths of the respective colors are adjusted to be almost equal to each other. A projection image display apparatus comprises the analyzing-synthesizing optical unit.

Abstract: A projection type display device, having a light beam flux converting optical system which makes plural beam fluxes from light emitted from a light source and converts the each beam flux into a parallel beam flux and makes the each beam flux advance in a different direction, a polarized light separating color separating optical system which polarization separates and color separates light which was emitted from the light beam flux converting optical system, plural reflecting type light valves which modulate polarized light components emitted from the polarized light separating color separating optical system based on image information and a color synthesizing and analyzing optical system performing color synthesis and analysis of modulated light which were emitted from the plural reflecting type light valves.

Abstract: To suppress light loss without deteriorating resolution of a projected image, light is first polarized and separated by a polarizing beam splitter. Green light is separated from a light flux emitted by the polarizing beam splitter by a dichroic mirror having a green light reflection property. A light flux containing blue and red light, which is transmitted by the dichroic mirror, is separated into red light and blue light by a dichroic prism. Resultant color light is modulated and reflected by reflection light valves, returned to the corresponding dichroic mirror or dichroic prism, and combined by the dichroic mirror and the dichroic prism. Resultant combined color light is projected via the polarizing beam splitter and a projection lens. The dichroic prism transmits s-polarized light having wavelengths less than a wavelength substantially within a wavelength band of green light and reflects s-polarized light having larger wavelengths.

Abstract: The projection type display apparatus according to the present invention has a prism for separating incident light into a plurality of light components and combining the plurality of modulated color components. The prism is constituted by a plurality of prism assemblies, each including an optical member made of an optically transparent material having a photoelastic constant whose absolute value is not greater than +1.5×10−8 cm2/N with respect to the incident light. More preferably, these plurality of prism assemblies are arranged such that each of a plurality of the separated color components is totally reflected by any of the prism assemblies.

Abstract: Projection displays are disclosed that reduce the loss of image contrast due to angle-of-incidence and color dependencies of liquid crystal display panels, polarizing beamsplitters, and dichroic reflectors. The projection displays comprise an illumination source that provides a light flux that made uniform by an integrator. A color separation system then divides the light flux into red, green, and blue color components. The color-components are directed through field lenses to polarizing beamsplitters and then to liquid crystal light valves. The color components are reflected by the light valves back through the polarizing beamsplitters to a projection lens that forms an image. The projection lens is preferably telecentric. Field lenses are provided that direct substantially collimated color components to the liquid crystal light valves.

Abstract: A cross dichroic prism comprises four triangular prisms having isosceles right triangular cross sections identical in shape, opposing side faces thereof being bonded and secured together with rectangular portions thereof facing each other; and a dichroic film having an X-shaped cross section formed between the bonding faces of the triangular prisms; wherein, of the four triangular prisms, a given prism and at least one of the prisms adjacent thereto have a refractive index difference therebetween of 0.00005 or less, and the remaining two prisms opposed thereto have a refractive index difference therebetween of 0.00005 or less.

Abstract: An analyzing-synthesizing optical system has the structure in which for each of the three primary colors of R, G, and B, there are provided a light valve for modulating incident light and a polarization beam splitter for guiding specific polarized light to this light valve and extracting only modulated light coming from the light valve to output it, wherein these light valves and polarization beam splitters are fixed as integrated with a synthesizing optical system comprising a cross dichroic prism and wherein optical path lengths of optical paths of the respective colors are adjusted to be almost equal to each other. A projection image display apparatus comprises the analyzing-synthesizing optical unit.

Abstract: An analyzing-synthesizing optical system has the structure in which for each of the three primary colors of R, G, and B, there are provided a light valve for modulating incident light and a polarization beam splitter for guiding specific polarized light to this light valve and extracting only modulated light coming from the light valve to output it, wherein these light valves and polarization beam splitters are fixed as integrated with a synthesizing optical system comprising a cross dichroic prism and wherein optical path lengths of optical paths of the respective colors are adjusted to be almost equal to each other. A projection image display apparatus comprises the analyzing-synthesizing optical unit.

Abstract: When a power switch is turned on, first and second analog switches are turned on while a third analog switch is turned off. Accordingly, at the time of starting, a forced excitation driving circuit supplies to a vibrator an oscillation output pulse which is substantially at the resonance frequency of the vibrator, thereby forcibly driving the vibrator in an excitation manner. Thereafter, when the vibrator substantially attains its stationary state and thereby the charged voltage of a capacitor reaches a threshold value of an inverter, the first and second analog switches are turned off while the third analog switch is turned on. Accordingly, the output of a self-excitation circuit is supplied to the electrode of the vibrator so as to vibrate the vibrator in a self-excitation manner.