Title:

**SOUND QUALITY ADJUSTING DEVICE AND FILTER DEVICE USED THEREFOR, SOUND QUALITY ADJUSTING METHOD, AND FILTER DESIGNING METHOD**

Document Type and Number:

WIPO Patent Application WO/2003/023961

Kind Code:

A1

Abstract:

A filter circuit is composed of FIR filters, and the filter factor is of a symmetrical type, thereby realizing a linear phase characteristic and preventing phase distortion even if a desired frequency band is emphasized. The first filter factors of a low−pass filter are determined so that the first filter factors may be the terms of a sequence in which the sum of the terms is not zero, the sign of the sum of every other terms is the same as that of the other every other terms, and the sum of the every other terms is equal to that of the other every other terms. Thus, by only changing a part of the signs of the filter factors, second filter factors of a high−pass filter can be simply determined so that they may be the terms of a sequence in which the sum of the terms is zero, the sign of the sum of every other terms is opposite to that of the other every other terms, and the absolute value of the sum of the every other terms is equal to that of the other every other terms.

Inventors:

Koyanagi, Yukio (409-1-D115, Nakao Saitama-shi, Saitama, 336-0932, JP)

Application Number:

PCT/JP2002/009047

Publication Date:

March 20, 2003

Filing Date:

September 05, 2002

Export Citation:

Assignee:

NEURO SOLUTION CORP. (4-7 Nakamachi 5-chome, Setagaya-ku, Tokyo, 158-0091, JP)

Koyanagi, Yukio (409-1-D115, Nakao Saitama-shi, Saitama, 336-0932, JP)

Koyanagi, Yukio (409-1-D115, Nakao Saitama-shi, Saitama, 336-0932, JP)

International Classes:

*;*

**H03G3/00***;*

**H03H17/02***; (IPC1-7): H03H17/06; H03H17/02*

**H03H17/06**Foreign References:

JPH06289898A | ||||

JPH06326555A | ||||

JPS5620320A | ||||

JPS635607A |

Other References:

See also references of EP 1427104A1

Attorney, Agent or Firm:

Tachibana, Kazuyuki (87-64, Oaza-Shimoshingashi Kawagoe-shi, Saitama, 350-1136, JP)

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