JPH0258788A - Display device for reproducing time - Google Patents

Abstract

PURPOSE:To obtain a reproducing time displaying device, the reproducing time displayed by which coincides with the actual reproducing time even when post-recording is performed only on an audio signal recording area by selectively counting a marker signal reproducing clock and frequency dividing signal is accordance with the reproducing mode and displaying a counted result in time as the reproducing time. CONSTITUTION:A frequency dividing means 7 which divides the frequency of marker signal reproducing clocks 6a obtained by reproducing marker signals 6 previously recorded at almost equal distances on the track of an information recording medium, selecting means 8 which selects the marker signal reproducing clocks 6a and frequency dividing signals in accordance with the reproducing mode, counting means 9 which counts the output pulse of the means 8, and displaying means 10 which displays a counted result of the means 9 in time are provided. Then the marker signal reproducing clocks 6a and their frequency dividing signals are selected in accordance with the reproducing mode by using the marker signal reproducing clocks 6a obtained by reproducing the marker signals 6 as reference signals. As a result, time measuring pulses having of almost fixed periods can be inputted to the counting means 9. Therefore, the displaying reproducing time can be made coincident with the actual reproducing time even when the reproducing mode is mixed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a playback time display device for displaying the playback time in an information recording/playback device such as an R-DAT (rotating head digital audio tape recorder). It is related to.

[Conventional technology]

Conventionally, R-DATs have a so-called after-recording function, in addition to normal recording of recording information on a magnetic tape, of rewriting recorded information on a predetermined portion of the magnetic tape that is currently recorded. The recording format of RDAT has a flock configuration as shown in Figure 4, with a PCM area 1 for recording audio signals such as music information,
It is divided into a subcode (SUB CODE) area 2 for recording subcode signals such as time information, and audio signals and subcode signals are recorded on the magnetic tape in this format. Normally, when performing after-recording, it is possible to rewrite only PCM area 1, only subcode area 2, or PCM area 1+subcode area 2.

When after-recording is performed only in the PCM iJf area 1, there is no change in the time information etc. previously recorded in the subcode area 2. RDAT recording methods are normal mode, which records and plays 100 frames per 3 seconds at the normal tape feed speed, and half-speed mode, which records and plays 50 frames per 3 seconds at the normal A tape feed speed. There are two types of modes [Zadat Conference
Standard Digital Audio Tape Recorder System June 1987, page 73 (THE DA
T C0NFERENCE STANDARD, DIGI
TAL AUDIOTAPE RECORDERS
See YSTEM). As shown in FIG. 5, information is recorded on the entire magnetic tape 3 for 60 minutes in normal mode, and as shown in FIG. Figure 6(b) shows the recording state of the magnetic tape 3 when after-recording is performed only on the PCM area in half-speed mode in the area (shaded area) from 20 minutes after (0 minute) to 40 minutes. .

When playing back in the recording state shown in Figure 6(a), the relationship between the tape playback time and the counter display time obtained by playing back the time information recorded in the subcode area is as shown in Figure 7. and both become equal.

However, when playing back in the recording state shown in Figure 6(b),
The relationship between the tape playback time and the counter display time is as shown in Figure 8. During the period in which after-recording was performed in half-speed mode, the time progress of the counter display time is half of the time progress of the tape playback time. Become.

[Problems to be Solved by the Invention] Since the conventional playback time display device is as described above, if after-recording is performed only in the PCM area in a mode different from the mode recorded before after-recording, the data may not be recorded in the sub-code area. Since the time information corresponds to the mode before after recording, the playback mode compatible with after recording is different from the recording mode of the time information. Problems such as the counter display time obtained from the time information recorded in the subcode area and the tape playback time are different because the time information is reproduced in that playback mode and the counter display time is obtained as it is. was there.

This invention was made to solve the above-mentioned problems, and it is possible to reproduce an information recording medium in which only the audio signal recording area has been subjected to after-recording, so that the actual playback time and display time match. The purpose is to obtain a time display device.

[Means to solve the problem]

The playback time display device according to the present invention uses a marker signal playback clock obtained by playing back marker signals recorded in advance at approximately equal intervals on a track of an information recording medium in an information recording and playback device capable of after-recording. Frequency division means for dividing the frequency, selection means for selecting the marker signal reproduction clock and the frequency division signal according to the reproduction mode, counting means for counting the output pulses of the selection means, and display means for displaying the counting results in time. It is equipped with the following.

[For production]

The reproduction time display device according to the present invention uses the marker signal reproduction clock that reproduces the marker signal as a reference signal, and the counting means has a substantially constant cycle each time the marker signal reproduction clock and its frequency division signal are selected according to the reproduction mode. It is possible to input pulses for time measurement, and even if playback modes are mixed, the actual playback time and display time will match.

(Example) Hereinafter, an example of the present invention will be explained with reference to the drawings.
The figure is a block diagram of an apparatus according to an embodiment of the invention. In the figure, 6a is a marker signal reproduction clock as reproduced time information, 7 is a frequency divider that divides the marker signal reproduction clock 6a by 2, and 8 is either the marker signal reproduction clock a or the output of the frequency divider 7. 9 is a counter that counts output pulses from the selector 8, and 10 is a display that displays the time from the count value of the counter 9.

FIG. 2 is a diagram showing the timing of the marker signal 6 recorded in the subcode area of the magnetic tape.

Next, the operation of the apparatus having such a configuration will be explained.

First, the time information marker signal 6 is placed in the subcode area of the entire length of the magnetic tape in 16 frames 217 as shown in FIG.
The data is repeatedly recorded in advance at intervals of 17 frames (approximately equal intervals between l/rack of the magnetic tape). In the case of after-recording only to the PCM area of the magnetic tape, the marker signal 6 recorded in the subcode area
No loss occurs and the record remains in its original state. During reproduction, the reproduction time count display is changed based on the marker signal reproduction clock 6a obtained by reading the recorded marker signal 6. This marker signal reproduction clock 6a is input to a frequency divider 7, frequency-divided by two, and input to a selector means 8. Since the selector means 8 is also directly inputted with the marker signal reproduction clock 6a, it selects and outputs one of the re-input signals according to the type of the reproduction mode signals S and 4 representing the reproduction mode. The selector means 8 is
When the reproduction mode is half-speed mode, the marker signal reproduction clock 6a is output, and when the reproduction mode is normal mode, a frequency-divided signal obtained by dividing the frequency of the marker signal reproduction clock 6a by two by the frequency divider 7 is output. The output pulses from the selector means 8 are counted by a counter 9.

The counting results are inputted to the display 10 and displayed in time. 16 frames, 17 frames, 17 frames total 50
Since the time interval for a frame corresponds to 3 seconds in half-speed mode, the signal input to the counter 9 is controlled by the frequency divider 7 and the selector means 8 with a period of approximately 1 second regardless of the playback mode. obtained as a clock. For this reason, as shown in Figure 6, from 20 minutes after the beginning of the magnetic tape that was first recorded in normal mode to 40 minutes, P is not recorded in half speed mode.
Even when a magnetic tape with only the CM area after-recorded is played back, the tape playback time and the time displayed on the counter on the display 10 match, as shown in FIG.

〔Effect of the invention〕

As described above, according to the present invention, the marker signal reproduction clock and its frequency divided signal are selected and counted according to the reproduction mode, and the counting result is displayed as the reproduction time, so that information can be recorded. By after-recording the medium, it is possible to match the actual playback time and display time even when playback modes are mixed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a display device according to an embodiment of the present invention, FIG. 2 is a diagram showing the generation timing of marker signals,
FIG. 3 is a diagram showing the relationship between tape playback time and counter display time according to one embodiment, FIG. 4 is an explanatory diagram showing the recording format of the tape, and FIG. 5 is an explanatory diagram showing the recording state of the magnetic tape. FIG. 6 is an explanatory diagram showing the magnetic tape recording state before and after after-recording, and FIGS. 7 and 8 are diagrams each showing the relationship between tape playback time and counter display time according to the conventional example. In the figure, 6... Marker signal, 6a... Marker signal reproduction clock, 7... Frequency divider, 8... Selector means, 9... Counter, 10... Display. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent: Masuo Oiwa

Claims (1)

[Claims] An information recording and reproducing device capable of after-recording that records an audio signal and a subcode signal on an information recording medium and rewrites the recording area of the audio signal,
a frequency dividing means for dividing a marker signal reproduction clock obtained by periodically reproducing a marker signal recorded in advance at approximately equal intervals on the tracks of the information recording medium; the marker signal reproduction clock and the frequency division means; a selection means for selecting and outputting an output signal according to a reproduction mode of the information recording medium, a counting means for counting output pulses from the selection means, and a display for displaying the results counted by the counting means over time. 1. A playback time display device comprising: means.