Control unit for a segment liquid crystal display and a method thereof

US9978325B2 · kind B2 · utility

Assignee

• NXP USA, Inc. · US

Inventors

• Viktor Fellinger · Niedernberg, DE
• Stefan Singer · Vaterstetten, DE

Key dates

• Filing date: Oct 21, 2013
• Grant date: May 22, 2018
• Expiry date: Jun 1, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G09G2330/028
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

A unit (10; 11; 12; 13) used to control a segment liquid crystal display (15; 16). The segment liquid crystal display (15; 16) includes at least a backplane electrode (20) and at least a front plane electrode (25) both associated with a same segment of the segment liquid crystal display (15; 16). The unit (10; 11; 12; 13) includes a controller (30; 40; 50) in order to generate a pulse-width-modulated control signal (35) that has two voltage levels and a variable duty cycle. The unit (10; 1; 12; 13) further includes an integrator (60; 61) to integrate the pulse-width-modulated control signal (35) and to provide an integrated control signal (90) which has more than two discrete voltage levels corresponding to different variable duty cycle values. An output of the unit (10; 11; 2; 13) supplies the integrated control signal (90) to the at least a backplane electrode (20) or to the at least a front plane electrode (25) so that visibility of the same segment in the segment liquid crystal display (15; 16) can be controlled. By having a pulse-width-modulated control signal (35) with only two voltage levels and different duty cycle values generated by the controller (30; 40; 50), and by hav…