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

• US 7,720,317 B2
• Filed: 02/28/2006
• Issued: 05/18/2010
• Est. Priority Date: 08/03/2005
• Status: Expired due to Fees

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Chiu, Yen-Chen, Liu, Jin-Lin
• Primary Examiner(s): BHATNAGAR, ANAND P
• Application Number:
  US11/363,050
• Publication Number:
  US 20070029464A1
• Time in Patent Office: 1,540 Days
• Field of Search: 382/100, 382/312, 382/313, 382/314, 382/315, 702/47, 702/104, 463/37, 345/156, 345/158, 345/159, 345/163, 345/169, 345/173
• US Class Current: 382/313
• 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;

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

(c) calculating said second side length according to said first side length, said ratio between the back-and-forth moving velocity and the leftward-and-rightward moving velocity, and one side length of the base block.

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. The device according to claim 1, wherein the step (c) comprises:

calculating said second side length according to the ratio between the maximum back-and-forth sensing velocity and the maximum leftward-and-rightward sensing velocity, and two formulae that the maximum back-and-forth sensing velocity is proportional to a difference between the second side length and one side length of the base block, and the maximum leftward-and-rightward sensing velocity is proportional to a difference between the first side length and one side length of the base block.