The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 28, 2001
Filed:
Jun. 08, 2000
Gi-Beom Kim, Kunpo, KR;
Abstract
A device for controlling brightness of a radio terminal. In the brightness control device, a photometer measures brightness of an incident light to generate an electric signal depending on the brightness. A light emitting device emits a light, and a power supply provides a power supply voltage to the light emitting device in response to a control signal. A controller measures brightness while the light emitting device is turned on/off, using the photometer, and generates the control signal for enabling the power supply to provide the power supply voltage to the light emitting device according to a brightness difference during light-on and light-off of the light emitting device. The controller comprises a switch for switching a signal output from let the photometer to either a first input node or a second input node of a comparator; the comparator for generating a signal corresponding to a difference between the signals received at the first and second input nodes thereof; and a pulse density modulation (PDM) signal generator for generating a PDM signal for the signal output from the comparator as the control signal.