# US 5,708,723 A · Recording and reproducing apparatus for audio signal

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,708,723 A
- Document ID: US5708723A
- Status: Granted
- Kind: A
- Application number: 08/697,780
- Filed: 1996-08-29
- Granted: 1998-01-13
- Earliest claimed: 1995-09-11
- Assignees: Sony Corporation
- Inventors: Yasuji Nishino
- Web page: https://patentgrep.com/patent/US5708723A

## CPC

- G11C 7/16: Storage of analogue signals in digital stores using an arrangement comprising analogue/digital [A/D] converters, digital memories and digital/analogue [D/A] converters
- G11C 2207/16: Solid state audio
- H04H 60/27: Arrangements for recording or accumulating broadcast information or broadcast-related information
- G11C: STATIC STORES (semiconductor memory devices H10B)
- H04H: BROADCAST COMMUNICATION (multiplex communication H04J; pictorial communication aspects of broadcast systems H04N)

## Abstract

A recording and reproducing apparatus for an audio signal including a low pass filter removing high frequency components of a predetermined frequency or more of an audio signal having a wide band, an A/D conversion circuit converting the audio signal from the low pass filter into a digital signal, a memory for storing in order to record a predetermined period of time of the digitized audio signal from the A/D conversion circuit, a D/A conversion circuit converting the audio signal read from the memory into an analog signal, a tone control circuit conducting a frequency correction on the audio signal, and a control circuit controlling the tone control circuit such that, with respect to the audio signal recorded in the memory or the audio signal read from the memory low frequency components of the audio signal to be reproduced are attenuated in correspondence with the high frequency components of the audio signal which have been removed by the low pass filter whereby the audio signal with no conspicuous unnaturalness can be reproduced.

## Claims

### Claim 1

A recording and reproducing apparatus for an audio signal, comprising:
a receiving circuit for demodulating an audio signal by receiving and selecting a radio broadcast wave;
an electric field strength detecting circuit for detecting an electric field strength of said radio broadcast wave received and selected by said receiving circuit;
a first tone control circuit for performing frequency correction on at least a low frequency region of said audio signal demodulated by said receiving circuit in accordance with the electric field strength detected by said electric field strength detecting circuit.
a low pass filter for removing high frequency components above a predetermined frequency from said demodulated audio signal and producing a filtered audio signal;
an A/D conversion circuit for converting said filtered audio signal from said low pass filter into a digital signal;
storing means for storing a predetermined time of length said digital audio signal from said A/D conversion circuit;
a D/A conversion circuit for converting said digital signal read from said storing means into an analog signal;
a second tone control circuit provided at a stage ahead of said low pass filter and for conducting frequency correction on said demodulated audio signal such that low frequency components thereof are attenuated; and
a control circuit for controlling said second tone control circuit to conduct frequency correction on said audio signal stored in said storing means in consideration of said frequency correction on said audio signal performed in said first tone control circuit and said high frequency components of said audio signal removed by said low pass filter based on the detected electric field strength by said electric field strength detecting circuit.

### Claim 2 (depends on 1)

The recording and reproducing apparatus for an audio signal according claim 1, wherein said storing means comprises a semiconductor memory.