Display Source Driver Switching for Stable Ramp-Signal Loads

Solution Overview

Problem

Digital-to-analog conversion using a ramp signal in display devices leads to fluctuations in load states, causing crosstalk and image quality issues due to varying load conditions on the ramp signal.

Innovation Solution

A display device with alternating groups of display elements and a source driver that includes a ramp signal generating circuit and switch circuit, allowing for synchronized switching of data lines to maintain consistent load states during digital-to-analog conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If digital-to-analog conversion using a ramp signal is performed by sampling and holding the voltage depending on the video signal value, then the video signal voltage can be generated for display elements, but the load state on the ramp signal changes depending on the display image causing crosstalk and image quality degradation

Engineering Contradiction:

Improvevideo signal voltage precisionVSAvoidcrosstalk

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The display elements are divided into first group and second group, with data lines also segmented into first data lines and second data lines. The ramp signal generating circuit generates separate ramp signals for each group, and the switch circuit selectively connects different data lines to the ramp signal output based on the scanning sequence. This segmentation isolates the load states of different display regions, preventing crosstalk while maintaining voltage precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The switch circuit dynamically changes the connection state between the ramp signal generating circuit and different data lines based on the scanning sequence. When scanning the first group of display elements, first data lines are connected to the ramp signal output; when scanning the second group, second data lines are connected. This dynamic switching maintains consistent load states on the ramp signal by preventing simultaneous connection to multiple data lines, thereby eliminating crosstalk.

Inventive Principle:

Principle #15Dynamics

2Manufacturing precision

If the ramp signal is supplied to the data line and the state is maintained until the gradation value is reached, then the video signal voltage can be set for display elements, but the load state on the ramp signal changes depending on the display image

Engineering Contradiction:

Improvevideo signal voltage setting accuracyVSAvoidload state stability

Core Design Contradiction:

Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The display elements are divided into first group and second group, with data lines also segmented into first data lines and second data lines. The ramp signal generating circuit generates separate ramp signals for each group, and the switch circuit selectively connects different data lines to the ramp signal output based on the scanning sequence. This segmentation isolates the load states of different display regions, preventing crosstalk while maintaining voltage precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The switch circuit dynamically changes the connection state between the ramp signal generating circuit and different data lines based on the scanning sequence. When scanning the first group of display elements, first data lines are connected to the ramp signal output; when scanning the second group, second data lines are connected. This dynamic switching maintains consistent load states on the ramp signal by preventing simultaneous connection to multiple data lines, thereby eliminating crosstalk.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12417747B2Display device, drive method for display device, and electronic apparatus

Publication Date: 2025.09.16 SONY SEMICON SOLUTIONS CORP

AI summary

A display device includes at least display elements arranged in a two-dimensional matrix, data lines provided for respective display element columns, and a source driver that supplies a video signal voltage to the data lines, in which a display element row includes a display element belonging to a first group and a display element belonging to a second group different from the first group, the source driver includes a ramp signal generating circuit and a switch circuit that causes a data line to hold a video signal voltage, and when output of the ramp signal generating circuit and a data line are switched from a connected state to a disconnected state in order to cause the data line corresponding to a certain display element to hold a video signal voltage, a data line corresponding to a display element belonging to a group different from the group, to which the certain display element belongs, and output of the ramp signal generating circuit are switched from the disconnected state to the connected state.