JPH0445175Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a digital audio disc player.

Background Art Digital audio disks have recently been put into practical use under the name compact disks (hereinafter referred to as CDs). In a CD player for playing such a CD, when recording a signal obtained from a CD onto a magnetic tape, the recording level must be set each time because the recording level differs depending on the type of tape. To do this, I listen to appropriate parts of the CD and set the levels. However, the level set in this way may not actually be optimal, or it may be necessary to find an appropriate part.
The drawback was that it took a lot of time to set the recording level.

Summary of the invention The purpose of the invention is to provide a digital audio disk player that can instantly set the optimum recording level when recording audio signals obtained from a CD onto a magnetic tape.

The digital audio disk player according to the present invention includes an information detection point movement control means for controlling the relative position of the information detection point of the pick-up with respect to the recording disk to jump in a predetermined manner in response to a command; A recording device comprising a selection means for selecting data obtained by the above, a storage means for storing the selected data, and an oscillation means driven and having an output level determined based on the data stored in the storage means. When recording an audio signal obtained from a disk onto a magnetic tape, the output of the oscillating means is configured to serve as a recording level setting signal.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, a laser beam passing through a beam splitter 2a and an objective lens 2b in an optical pickup 2 is focused onto the recording surface of a CD 1.
The reflected light from the recording surface of the CD 1 passes through the objective lens 2b and then enters the beam splitter 2a, where the incident light and the reflected light containing information are separated. The reflected light separated by the beam splitter 2a is irradiated onto a photoelectric conversion element 2c and converted into an electrical signal. The output of the photoelectric conversion element 2c is supplied to the servo circuit 3 and the data processing circuit 4 as the output of the pickup 2. The servo circuit 3 generates a focus error signal, a tracking error signal, and a phase difference signal according to the phase difference between the output of the pickup 2 and the reference signal, and adjusts the focus in the pickup 2 according to these error signals and the phase difference signal. It is configured to drive a cass actuator, a tracking actuator (not shown), and a servo motor 5 for rotationally driving the CD 1 and moving the pickup 2 in the radial direction of the CD 1. The data processing circuit 4 is an EFM (Eight to Fourteen)
The EFM demodulator is configured to perform deinterleaving, error detection, correction, correction, etc. of the data output from the EFM demodulator. The output data of the data processing circuit 4 is outputted to a D/A (digital/analog) converter 6 as an audio signal via a muting circuit 7.

On the other hand, data corresponding to the audio signal in the output data of the data processing circuit 4 is supplied to the arithmetic circuit 8. The arithmetic circuit 8 is configured to calculate the average value and peak value of data corresponding to the audio signal in the supplied data. The average value and peak value calculated by this arithmetic circuit 8 are stored in a memory 9 consisting of a shift register or the like. The average value and peak value stored in this memory 9 can be selectively converted into D/A by a changeover switch 10.
It is supplied to converter 11. This D/A converter 11
The output of becomes the control input of the oscillator 12. The oscillator 12 is configured to oscillate at an output level that corresponds to the level of the control input. This oscillator 12
The output becomes the recording level setting signal. The recording level setting signal and audio signal respectively output from the oscillator 12 and the muting circuit 7 are selectively output to the output terminal by the changeover switch 13.
Derived to OUT.

Further, control signals in the output data of the data processing circuit 4 are supplied to the system controller 14, and various information such as during a song, between songs, song number, performance time, etc. are read. This system controller 14 consists of a microcomputer, and responds to commands generated by pressing the recording level check switch 15 to control the servo circuit 3, data processing circuit 4, muting circuit 7,
It issues various commands to the arithmetic circuit 8 and memory 9.

System controller 14 in the above configuration
ROM in the microcomputer that forms
A sweep operation as shown in the flowchart of FIG. 3 is performed by a processor that processes data according to a program stored in advance. That is, when the recording level check switch 15 is turned on, the audio signal output from the DA converter 6 is muted, and at the same time the information detection point of the pickup 2 moves over k tracks (k is a constant). Figure 2 S1, S2). Then,
The data recorded on CD 1 is picked up 2.
The data is read by the data processing circuit 4 and supplied to the data processing circuit 4. In the data processing circuit 4, samples of data corresponding to the audio signal are extracted. That is,
On CD1, data is distributed according to a predetermined rule in order to reduce the effect of signal loss within a predetermined block, but the data of this predetermined block (not one frame) is, for example, one frame. Samples are taken out as one block or one block in two frames (the second
Figure S3). The samples extracted in the data processing circuit 4 are supplied to the arithmetic circuit 8. Arithmetic circuit 8
The average value and peak value of the data supplied are calculated and stored in the memory 9 (Fig. 2).
S4). Next, it is determined by the control signal whether sampling of the end of the data corresponding to the audio signal has been completed (S5 in Fig. 2), and the steps are continued until the sampling of the end of the data has been completed.
Processing after S2 is repeated.

The average value and peak value stored in the memory 9 by the above sweep operation are transferred to the changeover switch 1.
0 and then supplied to the DA converter 11 where it is converted into an analog signal. This analog signal is the oscillator 1
2, the output level of the oscillator 12 is set.

When the output of this oscillator 12 is used to record the signal obtained from the CD 1 onto a magnetic tape, the selector switch 13
By leading the output signal to the output terminal via the output terminal and supplying it to the tape recorder, the recording level can be set accurately.

In the above embodiment, the number of tracks that the information detection point of the pick-up 2 jumps over during the sweep operation is a constant number k, but the number of tracks increases each time the pick-up 2 jumps. It may be a number randomly selected from a group of natural numbers less than or equal to the track number. Further, in the above embodiment, the switch 10 is switched by the user, but a switch circuit that automatically switches between the average value and the peak value at regular intervals may also be used.

Furthermore, it is also possible to directly change the output level of the oscillator 12 using an average value or a peak value without using the DA converter 11.

FIG. 3 is a block diagram showing another embodiment of the present invention. In the figure, the same elements as in FIG. 1 are denoted by the same numbers. In this embodiment, the character information can be displayed by using the conversion interface 17 so that the character code is read by the arithmetic circuit 8, stored in the memory 9, and displayed on the display 16. In this case, character data
Text data can be output immediately by placing it on the first track of a CD, but the number of data tracks can be used effectively by inserting text data into the unrecorded areas between songs. can do. According to this embodiment, for example, the title of the song is displayed on the display, making it very easy to select a song, which is very effective in the case of an autochanger CD.

Effects of the invention According to the invention, a CD is swept, data on the CD is sampled and read out, an average value and a peak value are calculated from the read data, and an oscillator is activated based on these average values and peak values. Since it is driven so that the output level is determined and the output of the oscillator is used as the level setting signal, it is possible to set the accurate recording level in a short time when recording from CD to magnetic tape. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the device shown in FIG. 1, and FIG. 3 is a block diagram showing another embodiment of the present invention. be. Explanation of the symbols of the main parts, 2... Pick up,
4...Data processing circuit, 5...Controller, 8
... Arithmetic circuit, 9 ... Memory, 11 ... D-A converter, 12 ... Oscillator.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Information detection point movement control means for controlling the relative position of the pick-up information detection point with respect to the recording disk to jump in a predetermined manner in response to a command; It comprises a selection means for selecting data obtained by the pickup, a storage means for storing the selected data, and an oscillation means driven and having an output level determined based on the data stored in the storage means. . A digital audio disk player, characterized in that when recording an audio signal obtained from the recording disk onto a magnetic tape, the output of the oscillation means becomes a signal for setting a recording level. (2) The data selected by the selection means corresponds to an audio signal, the selection means calculates an average value and a peak value of the audio signal, and the oscillation means is driven by the average value and peak value. A digital audio disc player according to claim 1, characterized in that: