JPH01122047A - Digital audio tape recorder - Google Patents

Abstract

PURPOSE:To improve an operability by automatically recording a start ID and skip ID at the beginning and finishing of a musical signal at FM broadcasting receiving and recording times and reproducing the musical signal part only by automatically selecting it at reproducing time. CONSTITUTION:In case of stereophonic musical signal L and R being impressed on terminals 11 and 12 at FM broadcasting receiving and recording times a DC voltage is obtd. by passing the output of the substraction amplifier circuit 4 detecting the L-R signal through a rectifier circuit 5. In case of the DC voltage being larger than the threshold value '1' is taken and in case of the DC voltage being smaller than the threshold value '0' is taken as a narration signal or non-signal receiving time. And when the logical output is changed from '1' to '0' i.e., from a music to narration or non-signal, a skip ID is recorded in a subcode zone and a start ID at the time when changing from '0' to '1', so from narration or non-signal to the musical signal. The circuit 4 automatically records the start ID at the necessary place. The part excepting the musical is then quickly fed automatically at reproducing time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement in a digital audio tape recorder (hereinafter referred to as DAT), and particularly relates to an improvement in a digital audio tape recorder (hereinafter referred to as DAT), and in particular, when receiving and recording an FM broadcast, it is possible to record a narration signal during playback. The present invention relates to a control signal recording device for fast forwarding and reproducing only music signals.

[Prior Art] In conventional DAT devices, it has become possible to record various subcodes such as start ID, skip ID, etc. to facilitate detection of the tape position during recording and playback in the subcode area of the tape recording portion. ing.

As is well known, the start ID is a control signal that moves from fast-forward operation to playback operation, and Sugitsubu ID is a control signal that indicates the start point of fast-forward operation, and the part of the tape between where the skip ID and start ID are recorded is be done.

For example, if you record an FM broadcast and then record the skip ID at the start position of the narration signal when playing it back, and record the start ID at the start of the music signal that follows the narration signal, the next time you play it back, only the narration part will be fast-forwarded. The playback operation can be performed from the beginning of the music signal.

[Problems to be Solved by the Invention] This subcode in the J: Uni DAT can significantly improve the operability of the table fooder, but
It takes a considerable amount of time to accurately record the subcode during actual reproduction.

With Navi, if the start ID continues for a certain period of time without a signal, it can recognize that it is between songs and automatically record it, so there is no problem when recording records etc. that have been recorded with sufficient intervals between songs. However, if the narration signal and the music signal are repeated at relatively short time intervals, such as in FM broadcasting, the start ID cannot be automatically recorded between the narration signal and the music signal, so the start ID cannot be automatically recorded between the narration signal and the music signal. The starting position of the narration signal and the music signal must be searched for and recorded manually (by operating buttons) at that position, and it takes time to search for the starting part of the narration signal and the music signal.

[Means for Solving the Problem] This invention focuses on the fact that music signals contain many anti-phase components, detects anti-phase components in stereo signals, and detects anti-phase components when the anti-phase components are larger than a certain value, that is, a threshold value. If it is smaller than the threshold value, it is determined that a narration signal or no signal is being input, and when the narration signal or no signal changes to a music signal, the start ID is set as the music signal. This digital audio tape recorder automatically records a skip ID when a signal changes to a narration signal or no signal.

[Embodiment] In the embodiment shown in FIG. 1, 11 and 12 are L and R signal input terminals, respectively, 21 and 22 are bandpass filters whose pass bands are set to 400H2 to 10KIIZ, and 31 and 32 are amplifier circuits, respectively. 4 is a subtraction amplifier circuit, 5 is a rectifier circuit, and 6 is an output terminal.

In this circuit, only the signal components of 400112 to 10KIIZ of each signal applied to the L and R input terminals 11 and 12 pass through the band filters 21 and 22, respectively, and the respective signals are predetermined by the amplifier circuits 31 and 32, respectively. After being amplified to the level of , it is input to the subtraction amplifier circuit 4.

The subtraction amplifier circuit 4 includes a subtraction circuit that outputs a difference signal between L and R, and an amplifier circuit that amplifies the subtraction output until it is sufficiently saturated, and outputs a pulse signal corresponding to the difference between the L and R signals.

The pulse signal is input to the rectifier circuit 5, and the DC voltage is output to the output terminal 6.

The reason for converting into a pulse wave in the amplifier circuit is that if the signal is small, for example, below 0.6 V, which is the forward voltage of a silicon rectifier, the signal will be cut, making the operation unstable.

However, when converted into a pulse, the 0.6V wave can be ignored relative to the TT level around 5V, and by selecting the threshold value, the output signal rOJ, "1", can be output accurately.

Here, the narration signal and music signal in FM broadcasting were observed as a resurge 1 waveform using an oscilloscope.
Shown in Figures a to 3d.

FIG. 3a shows a music signal in stereo broadcasting, and it can be seen that it contains many anti-phase signal components.

FIG. 3b shows male and female narration signals in stereo broadcasting, and it can be seen that the negative phase component is significantly less compared to the music signal.

Moreover, FIG. 3C and FIG. 3D show only a male narration signal and only a female narration signal in stereo broadcasting, respectively, and it can be seen that there are even fewer negative phase components than in the former.

Therefore, when the stereo music signals g L and R are applied to the legitimate children 11 and 12, the output of the reduction/exemption amplifier circuit 4 that detects the opposite phase components of the L-R signals, that is, the two stereo signals, is passed through the rectifier circuit 5. DC voltage can be changed.

On the other hand, since the narration signal has few anti-phase components, the DC output has an extremely small value.

Therefore, when the DC voltage is larger than the threshold, the logic output is "1" when receiving stereo music, and when it is smaller than the threshold, the logic output is rOJ when a narration signal or no signal is received, and the logic output changes from "1" to rOJ. When changing, that is, when changing from a music signal to a narration signal or no signal, set the skip ID from "0" to "11".
When the signal changes from 1 to a narration signal or from no signal to a music signal, the start ID is recorded in the subcode area.

FIG. 2 is a block diagram of the part that records the skip ID and start ID.
Various subcode key outputs for selecting D8i, including skip ID, are sent to the CPU via the interface 7.
In addition to the well-known configuration in which the various IDs are input to CPU 8 and output from the CPU 8, the logic output is input to the CPU via interface 7, and the CPU outputs the skip ID and start ID in response to the logic output. to come out.

Therefore, according to this configuration, since the skip ID and start ID can be automatically recorded at necessary locations during FM broadcast reception and recording, parts other than the music signal can be automatically fast-forwarded during playback.

[Effects of the Invention] According to the invention described above, the start ID and skip I are set at the beginning and end of the music signal when receiving and recording FM broadcasting.
D can be recorded automatically, so only the music signal part can be automatically selected and played back during playback, and there is no need to manually record the ID while listening to the playback sound as in the past. Operability is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the music signal detection section of the present invention, and FIG.
The figure is a block diagram of the present invention, and Figures 3a to 3d are photographs of Lissajous waveforms of a music signal and a narration signal taken by an oscilloscope, respectively. Patent applicant: Onkyo Co., Ltd. ′ Yo2+(pa,

Claims (1)

[Claims] means for detecting an anti-phase component in a stereo signal; and a means for detecting an anti-phase component in a stereo signal;
”; and means for recording a skip ID in response to a change in the binary signal from “1” to “0” and a start ID in response to a change in the skip ID from “0” to “1”. A digital audio tape recorder comprising: