Handheld image-tracking device within rectangle-shaped two-dimensional sensing array

• US 20070029464A1
• Filed: 02/28/2006
• Published: 02/08/2007
• Est. Priority Date: 08/03/2005
• Status: Active Grant

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Chiu, Yen-Chen, Liu, Jin-Lin
• Granted Patent: US 7,720,317 B2
• Time in Patent Office: Days
• US Class Current: 250/208.100
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface

Abstract

Because the back-and-forth movement by hand is slower and more strenuous than the leftward-and-rightward swinging, a handheld image-tracking device, which can be applied to an optical mouse or a handheld scanner, uses a rectangle-shaped sensing array to save area of the sensing array and lower down the production cost for the device by reasonably reducing the back-and-forth sensing area for the sensing array; and, so, an amount and time spent for a data comparison in the device is lessened.

Claims

1. A handheld image-tracking device within a rectangle-shaped two-dimensional sensing array,

said sensing array comprising a first side length and a second side length,

said second side length is obtained through a block matching algorithm and a full search comprising steps of:

(a) obtaining a base block and a width for each pixel in said base block;

(b) calculating a maximum leftward-and-rightward sensing velocity and a maximum back-and-forth sensing velocity, said maximum leftward-and-rightward sensing velocity being a maximum velocity for swinging a human'"'"'s hand leftward and rightward, said back-and-forth moving velocity having a ratio to said leftward-and-rightward moving velocity with the same sense of force as said maximum velocity for swinging a human'"'"'s hand leftward and rightward

(c) calculating said second side length according to said first side length.

2. The device according to claim 1, wherein said ratio has a value between 0 and 1.

3. The device according to claim 1, wherein said base block is a square.

4. A handheld image-tracking device within a rectangle-shaped two-dimensional sensing array,

said rectangle-shaped two-dimensional sensing array comprising:

(a) a first side length; and

(b) a second side length,

wherein said image-tracking device is comprised of said rectangle-shaped two-dimensional sensing array; and

where in said second side length is shorter than said first side length.