Sanyo Electric Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Takeshi Fujisaki

Taichi Yoshimura

Toshiyuki Watanabe

Naoki Kaise

Kazunobu Oketani

Toshimasa Kanbara

Hiromitsu Okuno

Kazunori Kodama

A central position detection section has a detection width in which the central position has a median value along one axial direction. When the direction from a position, which is located at the time at which returning is started toward the central position is defined as a go direction, the control section commands that a drive mechanism should sequentially perform following operations: a first operation of driving a projection lens assembly in the go direction; a second operation of allowing the projection lens assembly to travel in a return direction at least by the detection width; and a third operation of allowing the projection lens assembly to travel in the detection width in the go direction by &#xbd; of the detection width traveled in the go direction.

Lens shift mechanism and projection image display device

A projection image display apparatus including a detachably attachable light source unit includes: a storage means provided to the light source unit and having previously stored therein information that the light source unit is a genuine product; a determination means making a comparison with the information in the storage means to determine whether the light source unit is the genuine product; and a light source control means controlling an output of the light source unit in accordance with a result from the determination means.

Projection display apparatus having stored information for authenticating light source

A image distortion correction unit which corrects a distortion of a projected image includes: a switching unit which operates in response to an operation signal from a Keystone remote controller button to switch correction by a trapezoidal distortion correction process and correction by a corner distortion correction process back and forth; a determination unit which determines whether any one of the correction by the trapezoidal distortion correction process and the correction by the corner distortion correction process has been performed; and a prohibition unit which prohibits switching the trapezoidal distortion correction process and the corner distortion correction process back and forth if the determination unit determines that any one of the correction by the trapezoidal distortion correction process and the correction by the corner distortion correction process has been performed and the operation signal is also received from the Keystone remote controller button.

Excellently operable projection image display apparatus

A video projector for displaying a picture based on a video signal. The video projector includes a first LCD panel for red light, a second LCD panel for green light, and a third LCD panel for blue light. A light source emits light toward the first to third LCD panels. A modulated light computer determines a correction coefficient for reducing the amount of light emitted from the light source toward the first to third LCD panels when temperature load of at least one of the first to third LCD panels increases. An emitted light amount control unit corrects the video signal with the correction coefficient and controls the amount of light emitted from the light source toward the first to third LCD panels.

Video projector

A projector comprises: a cooling fan for sucking ambient air through a filter; switching means for switching the operational mode of the cooling fan between a lowland mode and a highland mode; and control means adapted to obtain current fan voltage to determine the normal rpm value for that current fan voltage in reference to a highland voltage-rpm characteristic when the switching means is in the highland mode, obtain current fan rpm, and enables alarming means to issue a filter clogging alarm in the event that the current fan rpm is larger than the normal rpm value plus a predetermined value. Thus, filter clogging can be detected with precision in highlands.

Growing community of inventors

Amagasaki, Japan

Takeshi Fujisaki