Arrangement for driving display units with an adaptive start sequence

• US 20020130708A1
• Filed: 02/21/2002
• Published: 09/19/2002
• Est. Priority Date: 02/23/2001
• Status: Active Grant

• Current Assignee: Entropic Communications Incorporated (Maxlinear Incorporated)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Hohenwarter, Harald
• Granted Patent: US 6,914,473 B2
• Time in Patent Office: Days
• US Class Current: 327/540
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/026 Arrangements or methods related to booting a display
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

The invention relates to a circuit arrangement which includes a subvoltage generating unit and a voltage multiplier for generating at least one voltage Vmult, it being arranged to control the voltage multiplier by switching the voltage multiplier to a direct mode during a start time. The invention also relates to an arrangement for driving a display device, to a display device which includes such an arrangement, to an electronic apparatus which is provided with a display device for the display of image data which includes an arrangement for driving the display unit, and to a method of starting a circuit arrangement 15 which includes a subvoltage generating unit 40, a voltage multiplier 20 and a start control unit 30. In order to enable reliable and fast starting of such a circuit arrangement 15 while effectively using the available current and space at the same time, it is proposed to switch the voltage multiplier 20 to a direct mode by means of an initial start signal 36 during an adaptive start time ts, the variation of an activation signal 32 generated in the start control unit 30 being monitored and the control of the voltage multiplier (20) taking place in dependence thereon.

Claims

1. A circuit arrangement (15) for generating at least one voltage value (Vmult), which circuit arrangement includes a subvoltage generating unit (40) and a voltage multiplier (20), it being arranged to switch the voltage multiplier to a direct mode in order to control the voltage multiplier during a start time (ts).

2. A circuit arrangement as claimed in claim 1, characterized in that it is arranged to supply the voltage multiplier with an activation signal (32) formed from a subvoltage (Vdac) generated by the subvoltage generating unit and from a reference signal (Vref), and that it is arranged to supply the voltage multiplier with an initial start signal (36) formed from the activation signal (32) during the start time (ts).

3. A circuit arrangement as claimed in claim 1, characterized in that there is provided a start control unit for controlling the voltage multiplier, which start control unit includes at least one comparator (31) and a logic unit (35), the comparator being arranged to compare a subvoltage (Vdac) generated by the subvoltage generating unit and a reference voltage (Vref), and to generate the activation signal (32), the logic unit (35) generating an initial start signal (36) so as to switch the voltage multiplier to a direct mode.

4. A circuit arrangement as claimed in claim 1, characterized in that the start time (ts) during which the voltage multiplier (20) operates in a direct mode is adaptive adjustable.

5. A circuit arrangement as claimed in claim 1, characterized in that a series connection of switching devices (SWn) of the stages (Sn) in the voltage multiplier (20) is closed in the direct mode, and that the capacitances (CSn) associated with the stages can be disconnected.

6. A circuit arrangement for driving a display device, which arrangement includes a subvoltage generating unit (40) and a voltage multiplier (20), it being arranged to control the voltage multiplier (20) by switching the voltage multiplier to a direct mode by means of an initial start signal (36) during a start time (ts).

7. Voltage multiplier (20) for generating at least one voltage value (Vmult), containing a series connection of the stages (Sn) with switching devices (SWn), switching devices (SCn) and capacitances (CSn), characterized in that during a starttime (ts) the switching devices (SWn) are closed and by that a supply voltage (vdd) at the input of the voltage multiplier is switched to the output of the voltage multiplier.

8. A display unit (2) for the display of image data, which display unit includes an arrangement (15) for driving the display unit with a subvoltage generating unit (40) and a voltage multiplier (20), it being arranged to switch the voltage multiplier to a direct mode by means of at least one signal (36) during a start time ts.

9. An electronic apparatus which is provided with a display unit (2) for the display of image data and also with an arrangement (15) for driving the display unit, which arrangement includes a subvoltage generating unit (40) and a voltage multiplier (20), it being arranged that at least one signal (36) controls the voltage multiplier and that the voltage multiplier can be switched to a direct mode during a start time ts.

10. A method of starting a circuit arrangement (15) which includes a subvoltage generating unit (40) and a voltage multiplier (20), in which method a subvoltage value (Vteil) and a reference voltage (V-ref) are compared so as to generate an activation signal (32), the voltage multiplier (20) being switched to a direct mode during a start time (ts) which is adaptively adjusted by monitoring an activation signal (32).