Rotating Address Generator for Display Orientation

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Solution Overview

Problem

Display images fail to maintain proper orientation when a monitor or display device is physically rotated, due to the hardwired scan pattern of the device, resulting in incorrect positioning and display of images.

Innovation Solution

A software-based rotating address generator dynamically adjusts the scan order and address generation to match the new logical scan pattern after detecting a rotation, ensuring the display image is rendered in the desired orientation without the need for redundant data storage or significant video memory bandwidth usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a 3D accelerator chip or display hardware performs a blit operation to re-order display data for rotated orientation, then the display image orientation is corrected, but video memory bandwidth is drained and twice as much display data must be stored

Engineering Contradiction:

Improvedisplay image orientationVSAvoidvideo memory bandwidth

Core Design Contradiction:

Manufacturing precisionVSQuantity of substance

Solution Approach 1:

Instead of re-ordering display data in hardware to match the rotated physical orientation, the patent inverts the approach by keeping the display data in its original logical order and re-interpreting the physical pixel coordinates through a coordinate transformation system. The display hardware continues to scan in its fixed raster pattern, but the mapping between logical pixel coordinates and physical pixel positions is dynamically transformed based on the detected rotation angle, effectively correcting the orientation without re-ordering the data.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces a coordinate transformation system as an intermediary layer between the display data and the physical display hardware. This intermediary translates logical pixel coordinates into physical pixel positions based on the current rotation state, allowing the system to maintain correct image orientation without modifying the display data itself or requiring additional hardware processing of the pixel streams.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If a 3D accelerator chip or display hardware performs a blit operation to re-order display data for rotated orientation, then the display image orientation is corrected, but twice as much display data must be stored

Engineering Contradiction:

Improvedisplay image orientationVSAvoidvideo memory

Core Design Contradiction:

Manufacturing precisionVSVolume of stationary object

Solution Approach 1:

Instead of creating a second copy of display data in rotated orientation, the patent inverts the approach by maintaining a single copy of display data in its original logical orientation and using coordinate transformation to map it to the correct physical positions. This eliminates the need for duplicating display data in video memory while still achieving correct orientation display.

Inventive Principle:

Principle #13The other way round (Inversion)

3Device complexity

If the display device continues to physically scan pixels in the same hardwired direction after rotation, then the device structure remains simple, but the display image appears sideways with incorrect positioning

Engineering Contradiction:

Improvedisplay device structureVSAvoiddisplay image orientation

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical approach of physically reorienting the display hardware scan pattern with a software-based coordinate transformation system. Instead of modifying the hardwired raster scan mechanism, the system uses mathematical transformations to map logical pixel coordinates to physical pixel positions, effectively substituting a software solution for what would otherwise require complex hardware modifications.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent dynamically changes the coordinate mapping parameters based on the detected rotation state. The transformation equations use the rotation angle as a variable parameter to adjust how logical coordinates map to physical positions, allowing the system to adapt to different rotation states without changing the physical hardware configuration or scan pattern.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9202444B2Generating translated display image based on rotation of a display device

Publication Date: 2015.12.01 RED HAT INC

AI summary

Embodiments relate to systems and methods for generating address information to translate the order in which memory locations are accessed in a video buffer, to maintain a desired orientation in a rotated display. A video buffer is filled with display data to drive a CRT, LCD, or other display screen, starting with the upper-left corner. When the user rotates the display screen, the display screen continues to scan from the same starting corner, resulting in a misaligned orientation. In embodiments, a correct orientation can be automatically generated by determining a scan direction for the rotated display. The physical location of the new logical starting pixel is determined, and the rows and columns of the display image are rendered in a revised logical order which compensates for the amount and direction of rotation.