JPH04177676A - Information recorder/reproducer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention provides an information recording/reproducing device, such as an optical disc, etc.
The present invention relates to an information recording and reproducing device that performs error detection and correction during reproduction.

[Conventional technology]

As shown in FIG. 3, conventional error detection and correction of this type has a configuration in which the number of errors in the C2 direction is detected and it is determined whether the error can be corrected.

[Problem to be solved by the invention]

However, in the conventional example described above, since only the comparison between the information data in the C2 direction and the C2 parity added by the same data in the C2 direction is performed, the byte shift of the information data may occur due to erroneous detection of data marks during playback. The disadvantage is that it cannot be detected when it occurs. An object of the present invention is to provide an information recording and reproducing apparatus that detects byte shifts in information data read from a storage medium and enables better error detection and correction during reproduction.

[Means to solve the problem]

In order to solve this problem, the information recording/reproducing apparatus of the present invention has the configuration shown below. That is, in an information storage/reproduction device that reproduces data stored in a storage medium in response to an external request and transmits the data to the outside, a first processing means that performs one-way error detection/correction of the read data; 1st
and second processing means for detecting and correcting errors in a direction perpendicular to the above direction if no error is detected by the processing means.

[Effect]

In such a structure of the present invention, the second processing means performs error detection and correction processing on the processed data after the error detection and correction processing has been performed by the first processing means, thereby checking the presence or absence of a byte shift and increasing reliability. It operates in such a way as to obtain specific data.

【Example】

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a block diagram of the information recording/reproducing device 113 of this embodiment. In the figure, lot is a host computer that sends recording data to or receives data from the information recording/reproducing apparatus 113 of the embodiment. The information recording/reproducing device 113 has the configuration shown below. 102 is a host interface unit for exchanging data with the host computer 101, for example, a 5C
5I etc. 103 is a CPU that controls the entire device
, 104 is an RO that stores CPU operation processing procedures, etc.
M, 105 is an RA quotient used as a work area for the CPU 103, 106 is a buffer RAM, 107 is a disk control section, 108 is an ECC 1111 is a disk interface section interposed between the disk drive 112 and the disk controller 107, and for example, an ESD
I, etc. Next, the operation when reading data from the disk in the above configuration will be explained. Data read from the disk drive 112 is supplied to the disk controller 107 and ECC 108 via the disk interface 111, and is sent to the buffer R.
It is stored in AM106. If there is an error in the read data at this time, ECC1
However, for example, if a byte shift occurs in the data, this cannot be detected only by error detection in the C2 direction. Therefore, in the embodiment, in addition to error detection in the C2 direction,
By performing direction error detection, it is detected that a byte shift has occurred. The data reproduction processing procedure in the embodiment is processed according to the flowchart shown in FIG. First, in step 5201, data is read, and in the next step 5202, error detection in the C2 direction is performed, and correctable errors are corrected. If the error cannot be corrected, the process advances to step 5206 to perform error processing (for example, send a status signal to that effect to the host computer 101). If the error in the C2 direction is not detected or if the error has been corrected, the process advances to step 5203, and error detection in the C1 direction is performed this time. At this time, if the number of re-errors is greater than a certain value (for example, if it is predetermined to be 3 or more, then this number is reached), it means that a data error due to byte shift has occurred, so step 5204 From step 5
The process advances to step 206, where predetermined error processing (rereading, etc.) is performed. If both the C1 and C2 directions are normal or corrected, the data is transferred via the host computer interface 102 in step 5205. Figures 3 and 4 show information data 6X6=36 bytes, C
Add 4 bytes of parity to each of the 1 and C2 directions,
It shows how it is played back from the recording medium. Normally, when there is no erroneous detection of data marks and no byte shift occurs during reproduction, reproduction can be performed as shown in FIG. 4. However, if a byte shift occurs, checking only in the C2 direction in FIG. 3 will result in it being determined that everything is being reproduced correctly, as in FIG. 4. Therefore, for example, even if all error detections in the C2 direction are correct, if three or more errors are detected in the C1 direction, this means that a byte shift has occurred. This makes it possible to prevent erroneous playback. As explained above, according to this embodiment, it is possible to detect the occurrence of byte shifts due to erroneous detection of data marks, etc.
It becomes possible to provide an information recording/reproducing device that is more reliable than before. Incidentally, in the embodiment, an information data error detection means for an information recording/reproducing apparatus is shown, but the present invention is not limited to this. This is because by using a similar method for error detection during information transfer in a communication device, image processing device, etc., error detection for similar information data can be performed, and data accuracy can be improved.

【Effect of the invention】

As described above, according to the present invention, it is possible to detect byte shifts in information data read from a storage medium, and to perform error detection and correction during reproduction more favorably.

[Brief explanation of drawings]

Figure 1 is a block configuration diagram of the information storage/reproduction device of this embodiment. Figure 2 is a flowchart for detecting byte shift errors during reproduction. Figure 3 is a conceptual diagram when byte shift occurs. Figure 4 is normal. FIG. 2 is a conceptual diagram during playback. In the figure, 101... host computer, 102...
Host interface section, 103...CPU, 104
... ROM, 105... RAM, 106-... Buffer RAM, 107... Disk control section, 1
08...ECC, 111...Disk interface unit, 112...Disk drive. Patent applicant Canon Co., Ltd., Yo, Ni 1=-"22 Agent Patent attorney Yasunori Otsuka (and 1 other person) -;, -1 Figure 2 Figure 3

Claims (1)

[Claims] In an information storage/reproduction device that reproduces data stored in a storage medium in response to an external request and transmits the data to the outside, a first process of performing one-way error detection/correction of read data. An information recording/reproducing apparatus comprising: means for detecting and correcting errors in a direction perpendicular to the direction when an error is not detected by the first processing means.