US 2010/0073353 A1 · DISPLAY METHOD, DISPLAY SYSTEM, MOBILE COMMUNICATION TERMINAL, AND DISPLAY CONTROLLER

Abstract

When there is a circuit that has to wait for one frame cycle to switch LCD resolution, a user feels uncomfortable because the resolution is switched while the screen is temporarily turned off and blackened or while the screen does keep display but causes flickers. When the user switches to an application that will display in QVGA mode on the LCD while the LCD is displaying in VGA mode, a synchronization signal, etc. are stopped from being output from an LCD controller within a vertical blank period (step S2). Then, a pseudo vertical synchronization signal whose cycle falls within the vertical blank period is generated by the LCD controller to trigger a circuit in a par/ser converting circuit triggered by a vertical synchronization signal (steps S3 to S5), and to realize resolution switching (steps S6 to S8). This prevents blackening/flickering of the screen when the resolution is switched.

Claims17

Dependent claims

A display method for switching a display resolution of a display device, which can display at an arbitrarily set resolution of a plurality of resolutions, to a desired resolution, by switching a frequency of a clock signal output from a circuit, which supplies said display device with the clock signal, a synchronization signal, and an image signal, to a frequency matched to the display resolution, while using the synchronization signal to trigger this frequency switching, comprising:

a first step (step S2) of stopping said circuit from outputting the synchronization signal to said display device;
a second step (step S4) of making a setting for switching the frequency of the clock signal from said circuit to a frequency matched to a display resolution of said display device after switching;
a third step (step S6) of making the setting for switching the frequency of the clock effective, by generating a pseudo synchronization signal having a cycle shorter than a blanking period of the synchronization signal and supplying said circuit with the generated pseudo synchronization signal;
a fourth step (step S9) of switching the display resolution of said display device to the desired resolution;
and
a fifth step (step S11) of, after the pseudo synchronization signal is output, starting supplying the synchronization signal to said display device via said circuit.

3 more elements

A display system that switches a display resolution of a display device, which can display at an arbitrarily set resolution of a plurality of resolutions, to a desired resolution, by switching a frequency of a clock signal output from a circuit, which supplies said display device with the clock signal, a synchronization signal, and an image signal, to a frequency matched to the display resolution, while using the synchronization signal to trigger this frequency switching, comprising:

a display controller that stops outputting the synchronization signal, and during a period in which outputting is stopped, generates and outputs a pseudo synchronization signal having a cycle shorter than a blanking period of the synchronization signal, and after the period, outputs the synchronization signal and image signals matched to a new resolution after switching;
a circuit that is supplied with the image signals and the synchronization signal from said display controller, and as triggered by the synchronization signal, outputs a clock signal having a frequency matched to the resolution after switching together with the image signals and the synchronization signal input thereto to said display device;
and
a control unit that controls said display controller, changes a setting for the frequency at which said circuit outputs said clock signal such that the frequency matches the display resolution of said display device after switching, and switches the display resolution of said display device to the desired resolution.

1 more element

A portable communication terminal that has at least a function for sending/receiving an e-mail and a function for performing voice communication with another terminal, and that displays various images, symbols, and characters on a display device that can display at an arbitrarily set resolution of a plurality of resolutions, comprising:

a display controller that, when switching a display resolution of said display device to a desired resolution, stops outputting a vertical synchronization signal within a blanking period of the vertical synchronization signal, and during this period in which outputting is stopped, generates and outputs a pseudo vertical synchronization signal having a cycle shorter than the blanking period of the vertical synchronization signal, and after the period, outputs the vertical synchronization signal and image signals matched to the desired resolution;
a circuit:
to which the image signals and a synchronization signal including the vertical synchronization signal are input from said display controller;
whose setting change is made effective by the vertical synchronization signal;
and which outputs a clock signal having an externally set frequency, together with the input image signals and synchronization signal, to said display device;
and
control means that controls said display controller, sets the frequency at which said circuit outputs the clock signal such that the frequency matches the display resolution of said display device after switching, and switches the display resolution of said display device to the desired resolution.

4 more elements

Dependencies are inferred from the claim text.

Display method, display system, mobile communication terminal, and display controller

Life of this patent

Display method, display system, mobile communication terminal, and display controller

Life of this patent

Abstract

Claims17