JPH02214071A - Digital audio reproducing device - Google Patents

Abstract

PURPOSE:To easily detect deterioration by providing an error frequency detection part, counting error detecting frequency or error correction universal frequency and giving an alarm when the counted value exceeds a certain value. CONSTITUTION:A preset value is set in a presettable counter 2 every arrival of a reset signal A. Every time an error is detected by a decoder 1, an error flag is displayed and value is counted down from the preset value. When the error detection flag generating frequency of the decoder 1 becomes high and the counted value of the counter 2 is equal to zero or below, the counter 2 gives borrow output. An FF circuit 3 is set with the borrow output and an alarm display part 4 is actuated so as to perform display or give the alarm. The deterioration of reproducing characteristic or the deterioration of a source which performs reproducing is easily detected with such an alarm displaying action.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to digital audio playback devices such as compact disc (CD) players or digital audio technology (DAT) players.

The main causes of deterioration in playback characteristics in conventional CD players and DAT players are the adhesion of dust to the objective lens of the optical pickup in the former, and clogging of the head in the latter. To prevent the adhesion of dust and head clogging, in the former case, a special disk with a dust removal brush is used to remove the dust, and in the latter case, a head cleaning tape is used. . These can occur while the elapsed time after the dust has adhered is short, or while the amount of dust adhered is small.
Alternatively, the effect is large if the elapsed time after clogging is short or the degree of clogging is small.

Problems to be Solved by the Invention However, the conventional method of using a brush-equipped disk for dust removal or using a head cleaning tape does not allow for the elapsed time since dust has adhered or since the head has become clogged. However, if the amount of dust or clogging increases, the effect becomes smaller.On the other hand, in conventional digital audio playback devices, detection of deterioration in playback characteristics is done by listening to the deterioration of the playback sound. However, it was not possible to expect a significant effect on the adhesion of dust to the optical head and clogging of the optical head, which could detect deterioration by listening.

The present invention solves the above-mentioned conventional problems and provides a digital audio playback device that can detect dust adhesion to an optical head or clogging of the head at an early stage.

Means for Solving the Problems In order to achieve the above object, the present invention includes an error frequency detection section that counts the error detection frequency or the frequency of uncorrectable errors in the error detection/correction processing section, and a counted value of the error frequency counting section. The present invention is characterized by comprising an alarm display unit that monitors whether or not the value exceeds a certain value and displays or warns when the value exceeds the certain value.

Operation The present invention has the above-mentioned configuration, and when the error detection frequency or the uncorrectable error frequency exceeds a certain value, a display or warning is issued, and this display or warning causes the playback of the digital audio playback device to stop. Deterioration of characteristics or CD,
DAT deterioration can be easily detected.

Examples Examples of the present invention will be described below. In the figure,
1 is a Cl decoder that constitutes a part of the error detection/correction processing section of the CD player, and this decoder decodes 32 bytes (
Double errors in one frame data (4 bytes of parity) are detected and corrected, and double errors in one frame data are detected and corrected.
If there is an error even in a byte, an error detection flag is output.

2 takes in the preset value every time the reset signal A arrives at a fixed period (for example, 1 second), counts down from the preset value every time the error detection flag is input, and when the count value becomes O or less (When a borrow output occurs) A presettable down counter 4 sets the flip-flop circuit 3 in the subsequent stage, and while the flip-flop circuit 3 is set, it issues an alarm or display, and when the reset signal B arrives, the above-mentioned This is an alarm display unit that stops alarming or displaying when the flip-flop circuit 3 is reset.

In the above configuration, a preset value is set in the presettable counter 2 every time the reset signal A arrives. Every time an error is detected by the decoder 1, an error detection flag is output, and the error detection flag is used to count down from the preset value. When the occurrence frequency of the error detection flag output from the decoder 1 becomes high (and the count value of the presettable counter 2 becomes O or less), a borrow output is output from the presettable counter 2, and this borrow output causes the flip-flop circuit 3 to set, alarm display section 4
works. Thereafter, when the reset signal B is input to the flip-flop circuit 3, the flip-flop circuit 3 is reset and the alarm display on the alarm display section 4 stops. In this way, according to this embodiment,
The operation of the alarm display unit 4 may cause deterioration of the playback characteristics of the digital audio playback device or the sound of the source being played (CD
, DAT) can be easily detected.

Therefore, after taking measures to prevent dust from adhering to the optical pickup and clogging of the head, if the alarm display section 4 still continues to operate even if the same source as before the measures is used, then ■ the source has deteriorated. are doing. (2) The adhesion of dust to the optical pickup or clogging of the head is large enough that the above measures are insufficient. ■It is thought that this is due to deterioration in other parts of the device, and by changing the source and operating the playback device, it is possible to distinguish between the causes (■), (2), and (2).

Note that in the above embodiment, the alarm display section is operated by counting the frequency of error detection in the error detection/correction processing section, but the alarm display section may be operated by counting the frequency of errors that cannot be corrected. It is something.

Effects of the Invention The present invention has the above-described configuration, and can easily detect deterioration in the reproduction characteristics of a digital audio reproduction device and deterioration in the source with a simple configuration.

[Brief explanation of the drawing]

The figure is a block diagram of the main parts of a digital audio playback device according to an embodiment of the present invention. 1... Decoder, 2... Presettable counter,
3...Flip-flop circuit, 4...Alarm display section.

Claims (1)

[Claims] An error frequency counter that counts the error detection frequency or uncorrectable error frequency in the error detection/correction processing section, and an error frequency counter that monitors whether or not the counted value of this error frequency counter exceeds a certain value, and when it exceeds the certain value. A digital audio playback device characterized by having an alarm display unit that displays or warns.