Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Mitsuru Kotaka

Tsutomu Muraji

Shigekazu Yamagishi

Keiichi Kuzumoto

Toshiyuki Noguchi

Satoshi Hirotsune

Masato Tanaka

Yasuhiro Kakimoto

Yoshinobu Nakajima

Yoshinari Matsumoto

Kenji Kunitake

Shingo Oidate

A housing () that accommodates a light source (), a display device (), etc. has an intake aperture () and an exhaust aperture (). A blowing unit () sucks air in through the intake aperture and expels air out through the exhaust aperture. A filter unit () is disposed so that a filter () faces the intake aperture in a predetermined area between a rolling shaft () and a take-up shaft (). A part of the filter facing the intake aperture is renewed by taking-up the filter from the rolling shaft onto the take-up shaft. A control unit () performs control so as to renew the filter for a range that is smaller than an opening area of the intake aperture, when a predetermined renewal condition is determined to be satisfied, based on the output of a detection unit () that detects a specific factor value relating to contamination of the filter, such as a cumulative display time, a temperature, an air pressure, etc. This reduces a noise occurring during the driving of a fan or a change in the rotational speed of the fan, which are associated with automatic filter renewal.

Projector, and its filter renewal control method

The present invention includes: a rolled filter stretched between first and second winding shafts and, unused part of the filter being wound around the second winding shaft; a brush provided between the first and the second winding shafts so as to come into contact with a surface of the filter; a feeding mechanism for driving the first and the second winding shafts to take up or rewind the filter; and a feeding control unit for controlling the feeding mechanism. When activating a renewing operation for feeding unused part of the filter from the second winding shaft, the feeding control unit controls the feeding mechanism such that once the filter is taken up by the first winding shaft by an take-up amount La, the filter is rewound by the second winding shaft by a rewind amount Lb, and La and Lb satisfy a relationship La&#x2267;Lb. Without increasing the amount of the filter or the size of the device itself, the present invention can deliver adequate performance even in a dusty environment by a small number of filter renewing operations.

Dust capture device and projection type image display apparatus

An LCD projector (K ) comprising: a power source ( ); an image data source ( ) for producing an image data; a light source ( ) which is able to provide different levels of power; an LCD panel ( ) for modifying a light ray from the light source ( ) in accordance with said image data to produce light rays of an image; a projecting lens ( ) for projecting the light rays from the LCD panel ( ) onto a screen ( ) through enlargement; a control circuit ( ) for controlling an output of the power source ( ) so as to selectively set an output power: and a correcting circuit ( ) for correcting an image data before being supplied to the LCD panel ( ) so as to compensate the disturbance of the white balance caused by the change of the power of the light source ( ).

LCD projector

A progressive scanning conversion apparatus for converting an interlaced scan video signal into a progressive scan video signal by performing interpolation based on original pixels which are obtained in a matrix by sampling the interlaced scan video signal in a current field, original pixels which are obtained in a matrix by sampling the interlaced scan video signal in a previous field which is immediately prior to the current field, and original pixels which are obtained in a matrix by sampling the interlaced scan video signal in a next field which is immediately following the current field. The apparatus includes a motion vector detector for detecting a motion vector between two of the current field, the previous field, and the next field; a motion estimation circuit for estimating a pixel value in the current field, from one of a pixel in the previous field and a pixel in the next field using the motion vector detected by the vector detection means; and an interpolated pixel generator for generating an interpolated pixel used for conversion by multiplying the pixel value obtained by the motion estimation means and the corresponding pixel value in the current field by a weighting factor and summating the multiplication results.

Progressive scanning conversion apparatus

A projection type image display apparatus using a light modulation image display device as a light valve varies the voltage of a video signal so as to correct the nonuniformity of luminance of the optical device so that an image uniform in brightness and color even in peripheral parts can be displayed on a projection screen. A driving circuit contained with the apparatus generates three driving signals for driving three image display devices in accordance with red, green and blue color component signals of an input video signal. The driving circuit includes a correction circuit for correcting the red and blue color component signals independently of one another so that their luminance is commensurate with that of the green color component signal.

Growing community of inventors

Osaka, Japan

Mitsuru Kotaka