Mitsubishi Denki Kabushiki Kaisha

Chinontec Kabushiki Kaisha

Mitsubishi Electric Corporation

Motoo Takahashi

Kenji Samejima

Hiroki Abe

Tomoo Fujimori

Akihiro Yamada

Akira Daijogo

Tomohiro Bessho

Mitsuhiro Kawaguchi

Yoshinori Sato

Hiroshi Kida

Teruo Miyamoto

Kazuo Tsukagoshi

Tatsuro Hirose

Hiroyuki Yahara

Takaaki Uda

The invention provides a projection display that achieves continuous light amount control with ease and without causing unevenness of illumination of light applied to a light valve responsive to a video signal, thereby allowing constant image display with satisfactory contrast. The projection display of the invention includes a light valve (); a light source () generating light applied to the light valve (); an integrator lens () provided on an optical path between the light source () and the light valve () and making uniform the illumination distribution of light applied from the light source () to the light valve (); and a light amount control system () provided on the optical path and including a turning mechanism () which turns like a set of double doors in order to adjust the amount of light applied from the light source () to the light valve (). The turning mechanism () is bent into a V shape in a direction to reduce the amount of light (to block the light).

Projection display having improved light shielding bodies for adjusting the amount of light applied to a light valve therein

A projection display apparatus includes a light valve, a light source for producing light directed to the light valve, an integrator lens disposed in an optical path extending from the light source to the light valve and including a first lens array and a second lens array, and a light amount adjustment mechanism disposed in the optical path between the first lens array and the second lens array. The light amount adjusting mechanism includes a pair of light shielding elements pivoting in the form of a pair of double doors. The pair of light shielding elements have an opening formed in a region of tip portions thereof which corresponds to lens cells in contact with the optical axis of the second lens array. A region of the opening corresponding to one lens cell in contact with the optical axis of the second lens array is of a triangular configuration.

Projection display apparatus

A projection display apparatusin which the light quantity adjusting means has a simple and readily interchangeable structure, and which can improve image quality by adjusting the quantity of light received by a light valve continuously, without causing illuminance irregularities, and without having unwanted light radiated onto the screen, the light quantity adjusting meanshaving light blocking membersL,R for blocking light in transit to a second lens array, and rotational axesLA,RA for turnably supporting each of the light blocking members on an xy plane, the light blocking membersL,R and rotational axesLA,RA being positioned so that the rotational axesLA,RA are disposed in positions symmetric with respect to the optical axis AX on the xy plane, and the turning range from the light blocking initiation position at which the light blocking membersL,R, by being turned, start to block light in transit toward the second lens arrayto the maximum light blocking position at which the light blocking membersL,R block a maximum quantity of the light in transit toward the second lens arrayis equal to or less than ninety degrees.

A projection display apparatus is provided which offers improved contrast while smoothly controlling the amount of light, with a simple structure and without deterioration of lifetime due to the heat of the light from a light source. This projection display apparatus includes a light valve, a light source for emitting light to the light valve, an integrator lens disposed on the optical path of the light propagating from the light source to the light valve, for making uniform the illuminance distribution of the light from the light source, and a shutter mechanism disposed on the light path, for controlling the amount of light that illuminates the light valve. The shutter mechanism has a pair of light-blocking members having cuts formed in their respective protruding sides to regulate the passage of light, and the pair of light-blocking members are moved straight to protrude/retract on the optical path, perpendicularly to the optical path from both sides of the optical path, so as to control the amount of the light according to the extent of their protrusion on the optical path.

The invention provides a lens device of a projector for projecting light that has been modulated and emitted by a display device, wherein said lens device has an optical axis and is arranged telecentric to rays of light emitted from said display device, said lens device has a diaphragm mechanism having an aperture at such a position that the lens device causes principal rays emitted from various locations on the display device to intersect with the optical axis, and said aperture is substantially trapezoidal.

Lens device and projector having diaphragm mechanisms with substantially trapezoidal apertures

The invention provides A lens device of a projector for projecting light that has been modulated and emitted by a display device, wherein said lens device has an optical axis and is arranged telecentric to rays of light emitted from said display device, said lens device has a diaphragm mechanism having an aperture at such a position that the lens device causes principal rays emitted from various locations on the display device to intersect with the optical axis; and said aperture is shaped such that sides of the aperture curve inward approximately along lines that connect areas having substantially similar levels of contrast.

Lens device and projector having diaphragm mechanisms with apertures having inwardly curved sides

The invention provides a projector having a light source, a display device to modulate light emitted from the light source, a lens device to project light emitted from the light source via the display device, wherein the lens device has a diaphragm mechanism formed having an aperture, an ambient light illuminance detector to measure illuminance of ambient light, a projected image illuminance detector to measure illuminance of an image projected on the screen, an illuminance comparator to compare an illuminance detected by the ambient light illuminance detector and an illuminance detected by the projected image illuminance detector, and a diaphragm mechanism/image signal controller to control an intensity of image signals input into the display device and to control a size of an opening of the aperture of the diaphragm mechanism in accordance with a result of comparison by the illuminance comparator.

Projector having an illuminance detector

The invention provides a lens device of a projector for projecting light that has been modulated and emitted by a display device, wherein said lens device has an optical axis and is arranged telecentric to rays of light emitted from said display device, said lens device has a diaphragm mechanism having an aperture at such a position that the lens device causes principal rays emitted from various locations on the display device to intersect with the optical axis, and said aperture is substantially square.

Lens device and projector having diaphragm mechanisms with substantially square apertures

The invention provides a lens device of a projector for projecting light that has been modulated and emitted by a display device, wherein said lens device has an optical axis and is arranged telecentric to rays of light emitted from said display device, said lens device has a diaphragm mechanism having an aperture at such a position that the lens device causes principal rays emitted from various locations on the display device to intersect with the optical axis, and said aperture is substantially triangular.

Lens device and projector having diaphragm mechanisms with substantially triangular apertures

The invention provides a projector having a light source, a display device to modulate light emitted from the light source, a lens device to project light emitted from the light source and modulated by the display device, wherein the lens device comprises a diaphragm mechanism, an image signal intensity detector to detect image signals input into the display device and to evaluate an intensity of the signals, a diaphragm mechanism drive control to drive the diaphragm mechanism so as to reduce the size of an aperture of the diaphragm mechanism when the image signal intensity detector ascertains that the intensity of the image signal is lower than a given level, and an image signal controller to increase the intensity of the image signal when the image signal intensity detector ascertains that the intensity of the image signal is lower than a given level.

Projector having an image signal controller

The invention provides a lens device and projector in which light passing through liquid crystal panels is projected on a screen using the lens device. The lens device includes a diaphragm mechanism. A telecentric optical system for the display device is provided between the diaphragm mechanism and the liquid crystal panels. An aperture of the diaphragm mechanism is positioned at a location where primary rays that are emitted from the liquid crystal panels parallel to an optical axis intersect with the optical axis. Contrast characteristics of the liquid crystal panels vary depending on angles and directions of incidence of rays of light. The aperture of the diaphragm mechanism is formed in a substantially triangular shape in accordance with the shape of the contrast characteristics.

Projection lens device and projector

A projecter having a lamp, a lamp box containing the lamp, an outlet fan for discharging air from the lamp box, an optical system member which receives a light beam from the lamp and outputs an image light, an optical system box containing the optical system member, and an inlet fan for blowing outside air into the optical system box. The projector also has a first ventilating duct that directs the outside air blown in by the inlet fan into the lamp box.

Projector with inlet fan, outlet fan and ventilation duct structure for cooling an optical system

A light source apparatus has a luminescent tube, a reflecting mirror, a securing member and bonding material as a holding member disposed to block a part of a small opening of the reflecting mirror and holding the luminescent tube in the reflecting mirror, a transparent protection plate for blocking the large opening of the reflecting mirror, a ventilator for sucking air inside the reflecting mirror through the small opening and sending out the air through an outlet, and a housing for combining the reflecting mirror and the ventilator; and the reflecting mirror includes an air inlet disposed closer to the large opening than a center position of the luminescent tube.

Light source apparatus

A video projector includes a cabinet having a scren mounting opening, a projector unit housed within the cabinet, and a generally rectangular composite projection screen secured to the cabinet to cover the screen mounting opening and a picture is projected from the projector unit onto the screen. The composite screen includes a laminar structure of a Fresnel lens plate and a lenticular lens plate. The lenticular lens plate has a height smaller than the height of the Fresnel lens plate and an upper edge connected by adhesive tape with an upper edge of the Fresnel lens plate such than a lower edge of the lenticular lens plate opposite to the upper edge is offset in an upward direction relative to a lower edge of the Fresnel lens plate to provide a margin extending along the width of the composite screen for accommodating the expansion of the lenticular lens plate. The composite screen is secured to the cabinet and covers the screen mounting opening so that a gap can be formed between the upper clamping fixture and the top edge of the composite screen.

Growing community of inventors

Tokyo, Japan

Motoo Takahashi