Patent ID: 7945794

Claim:
A portable computer with a power control function comprising: a hinge having a first part and a second part pivotally coupled to the first part; a first body affixed to the first part of the hinge; a second body affixed to the second part of the hinge and rotatable with the second part of the hinge relative to the first body; an optical sensor mounted on the first body, the optical sensor having transmitter means and receiver means, the transmitter means being adapted to emit a beam to the receiver means; an optical grating connected to the second part of the hinge and rotatable with the second part of the hinge relative to the first part, the optical grating having a plurality of openings and a plurality of blocking zones, the optical grating having at least one part located between the transmitter means and the receiver means such that the optical sensor generates a first sensing voltage when one of the blocking zones blocks the beam from the receiver means, the optical sensor generating a second sensing voltage when the beam passes through one of the openings to the receiver means; a backlight module mounted in the second body; and a control circuit electrically connected to the optical sensor and the backlight module; wherein when the second body is rotated to a second open angle with respect to the first body, the control circuit generates a second control signal for controlling the backlight module to be on half brightness according to the first and second sensing voltages; when the second body is rotated to a third open angle with respect to the first body, the control circuit generates a third control signal for controlling the backlight module to be on full brightness according to the first and second sensing voltages.