Coordinate input device depending on input speeds

• US 6,028,594 A
• Filed: 06/03/1997
• Issued: 02/22/2000
• Est. Priority Date: 06/04/1996
• Status: Expired due to Term

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Inoue, Kinya
• Primary Examiner(s): Saras, Steven J.
• Assistant Examiner(s): Bell, Paul A.
• Application Number:
  US08/868,039
• Time in Patent Office: 994 Days
• Field of Search: 345/173, 345/179, 345/174, 345/175, 345/176, 345/177, 345/178, 345/156, 345/157, 345/159, 84/600, 356/419, 704/203, 704/205, 704/225, 704/229, 250/226
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

There is provided a coordinate input device in which when a coordinate input object is moved on a tablet while being in contact with the tablet, and this state is displayed with cursor movement, fine movement or delay movement of the cursor does not occur. The coordinate input device is constituted by a tablet operated by a coordinate input object and a coordinate data generation section for generating coordinate data representing a coordinate position on the tablet operated by the coordinate input object, and the coordinate data generation section comprises a moving speed detection section for detecting a contact moving speed of the coordinate input object on the tablet and a fine movement removing filter for removing an unnecessary frequency component included in the coordinate data, so that a cutoff frequency of the fine movement removing filter is switched in accordance with the moving speed detected by the moving speed detection section.

Claims

1. A coordinated input device comprising

an operation area operated by a coordinate input object;

a coordinate data formation section for generating coordinate data representing a coordinate position on said operation area operated by said coordinate input object; and

a signal processor for processing the coordinate data to display the coordinate data, characterized in that said coordinate data formation section comprises a moving amount detection section for detecting a moving speed of said coordinate input object on said operation area and a variable filter for removing an unnecessary frequency component included in the coordinate data, said variable filter using the weight of a running average as a filter constant, the moving speed having a characteristic intermediate frequency;

wherein;

the weight of the running average is set in response to the amount of change in the moving speed, as detected by the moving amount detecting section, such that the frequency component of the moving speed of the coordinate input object is not attenuated;

the cutoff frequency of the variable filter is changed in response to the change in the weight of the running average; and

the frequency difference between the cutoff frequency and the characteristic intermediate frequency is constant, the cutoff frequency being higher than the characteristic intermediate frequency.

2. A coordinate input device according to claim 1 characterized in that, as said variable filter, a filter having a multi-layer structure is used.

3. The coordinate input device according to claim 1, wherein the detection of the moving amount of coordinate is calculated in reference to a difference between a previous coordinate position and a present coordinate position, the moving amount being divided into a plurality of stages and the weight of the running average being set for every stage in response to the moving amount.