Sanyo Electric Co., Ltd.

Naoki Kaise

Yoshichika Hirao

Toru Kirimura

Koji Muraoka

Toshiyuki Watanabe

Takeshi Fujisaki

Ryoji Nakanishi

Kazunori Kodama

Kenji Ofune

Hidetomo Kawashige

Kenji Hyakutake

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 includes a display device which receives an image signal and generates image light projected onto a projection surface. A scaling processor scales the input image signal. An OSD processor generates and corrects an adjustment pattern image in accordance with a correction instruction on the projection surface. An image signal synthesizer combines the image signal processed by the scaling processor with an OSD image signal generated and corrected by the OSD processor to generate a combined image signal. A trapezoidal distortion corrector performs trapezoidal distortion correction on the combined image signal from the image signal synthesizer based on the correction of the adjustment pattern image on the projection surface. The adjustment pattern image generated by the OSD processor includes a reference quadrangle pattern and downsized quadrangle patterns, which are reduced in size from the reference quadrangle pattern.

Video projector

An image display device capable of preventing erroneous activation of the theft prevention function is provided. The image display device includes a theft prevention unit having an alarm function for preventing theft of the image display device, and a control circuit for controlling the theft prevention unit. The control circuit invalidates the alarm function of the theft prevention unit before the image display device is shipped out of a factory.

Image display device

A projection type video display has a sensor which includes an image pick up device to take a projected image and the projection type video display projects an adjustment image to automatically implement the focus adjustment and the keystone distortion correction on the basis of output of the sensor.

Projection type video display

At the time of manual adjustment, a motor driving signal corresponding to a user's key operation is fed to a focusing motor from a microcomputer through a switch. At the time of automatic adjustment, the switch selects a motor driving signal from a sensor and feeds the selected motor driving signal to the focusing motor. The sensor contains a dedicated microcomputer. The dedicated microcomputer samples an image pick-up signal of a CCD line sensor in the sensor to generate contrast data, and automatically drives the focusing motor, to automatically make focusing adjustment.

A display device comprises a nonvolatile memory for storing an amount of adjustment obtained in a blanking adjustment most recently performed for a particular video signal, means for judging whether or not the particular video signal is inputted, means for masking a region defined by the amount of adjustment, obtained in the blanking adjustment, stored in the nonvolatile memory at a black level when the particular video signal is inputted, means for allowing the blanking adjustment based on a user operation only when the particular video signal is inputted, and means for updating the amount of adjustment, obtained in the blanking adjustment, stored in the nonvolatile memory, when it is changed by the user operation, to the changed amount of blanking adjustment.

Display device

A projection type video display apparatus in which a display device transmits light emitted from a light source to project a video written into the display device is characterized by comprising person detection means for detecting a person who exists within a projected video area, and control means for changing the state of the projected video when the person detection means detects the person.

Projection type video display apparatus

A microcomputer performs image drawing processing of a projection video for adjustment by an OSD (On-Screen Display) circuit when it detects the press of an adjustment command key. The projection video for adjustment is an image having a black-and-white area high in contrast formed therein. The projection video for adjustment is picked up by a CCD line sensor in a sensor. A microcomputer has its input an image pick-up signal from the CCD line sensor, to make focusing adjustment and trapezoidal distortion correction on the basis of the image pick-up signal.

Projection type video display and method of adjusting the same at factory shipping

In a projection type display device having an electrical trapezoidal distortion correcting function, there are provided detection means for detecting an angle of inclination in the vertical direction of an optical axis of the projection type display device toward a screen surface, and control means for controlling the display position of an on screen display image displayed in a screen on the basis of the angle of inclination detected by the detection means.

Projection type display device

A cooling fan controller controls a voltage for driving a cooling fan on the basis of a temperature detected by a temperature sensor. A first controller controls voltage for driving the cooling fan to a minimum voltage for starting the cooling fan. A second controller controls the voltage for driving the cooling fan to a driving voltage value corresponding to the detected temperature after the cooling fan is started. A relationship between the detected temperature in the voltage for driving the cooling fan is such that the higher the detected temperature becomes the larger the voltage for driving the cooling fan becomes. A predetermined minimum voltage for cooling fan control is lower than the minimum voltage for starting the cooling fan and a predetermined maximum voltage for cooling fan control is higher than the minimum voltage for starting the cooling fan.

Growing community of inventors

Higashiosaka, Japan

Naoki Kaise