International Business Machines Corporation

Lenovo (singapore) Pte. Ltd.

Takaaki Sakurai

Moriyuki Tsuchihashi

Satoshi Karube

Yoshiteru Watanabe

Kohji Inoue

Yi Zeng

Toshiyuki Yana

Susumu Hattori

An electronic device having a liquid crystal shutter is disclosed. A liquid crystal shutter is provided in an area formed by expanding a liquid crystal display. The liquid crystal shutter includes a rear polarizer, a rear glass substrate, a segmented electrode, a liquid crystal, a counter electrode, a front glass substrate, a shutter aperture, and a front polarizer. A camera module is disposed behind the rear polarizer. A voltage applied to the segmented electrode can be controlled to visually expose or hide the lens of the camera module from a shutter aperture.

Electronic device having a liquid crystal shutter

A liquid crystal power supply is provided which generates a high-precision drive power supply voltage supplied to a driver circuit by using a low-precision reference voltage generating circuit. The power supply circuit includes a DC/DC converter which generates a voltage having a size based on an oscillation signal from a power supply voltage and outputs the generated voltage as a drive power supply voltage; a stabilized power supply circuit which generates a highest-level reference potential for generating a gray-scale voltage in a driver circuit; a comparison unit which outputs a difference voltage according to a difference between the drive power supply voltage and the highest-level reference potential; an internal reference voltage generating unit; an error amplifying unit which amplifies a difference between the reference voltage and the difference voltage; and a PWM conversion unit which outputs an oscillation signal in response to the amplified difference.

Power supply and reference voltage circuit for TFT LCD source driver

Growing community of inventors

Sagamihara, Japan

Takaaki Sakurai