JPS6052958A - Pcm recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a PCM recording signal of high fidelity without using two A/D converters by sampling/holding simultaneously both signals of the 1st and 2nd channels and delaying one of both signals to perform the alternating digital conversion. CONSTITUTION:Analog signals (a) and (f) of signal input terminals 15 and 16 of L and R channels are impressed to the inputs of amplifiers 1 and 3 respectively. The outputs of amplifiers 1 and 3 charge capacitors 12 and 13 connected to the inputs of amplifiers 2 and 4 via switches S6 and S7 which are controlled by a sampling/holding signal (b). Thus the held signals (c) and (g) are obtained at the outputs of amplifiers 2 and 4 respectively. The signal (g) is delayed by a switch S8, a capacitor 14 and an amplifier 5 which are controlled by a sampling/ holding signal (h) having a different phase from the signal (b). Thus a signal (i) is obtained. The signals (c) and (i) are impressed to switches S9 and S10 and selected by an A/D converter 11. In such a way, a PCM recording signal is obtained with high fidelity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a PCM recording and reproducing apparatus that uses a video tape recorder or a part thereof to record and reproduce PCM signals conforming to standard television signals.

Conventional Structure and Problems Conventionally, this type of device alternately samples and holds two analog signals and performs analog/digital conversion for recording and reproduction. Therefore, there is a limit to how high the fidelity can be increased. Further, if an A/D converter dedicated to each analog signal is used, the fidelity can be improved, but there is a drawback that the cost increases significantly.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a PCM recording and reproducing device that can improve fidelity without using two expensive A/D converters.

Structure of the Invention The PCM recording and reproducing apparatus of the present invention includes a first sampling system that samples and holds an analog signal as shown in FIG.
bold means, and second sampling/holding means for sampling and bolding the second analog signal at the same timing as the first sampling-small-hold means;
A third sample and hold means samples and holds the output of the second sample and hold means at a timing different in phase from the above-mentioned timing, and a first simple hold means and a third sample and hold means. A/D converter that alternately switches the output and converts it to digital, 1"
In the process of analog/digital conversion of the first and second two analog signals, both channels are simultaneously sampled and held to perform analog/digital conversion.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1st
2 and 2 do not show a block diagram and operation timing of the present invention, respectively. 1 to 5 are amplifiers, and 6 to 10 are mechanical or electronic switches.

12 to 14 are bold capacitors. Also, 15
, 16 are L channel and R channel signal input terminals, respectively.

To explain the configuration of FIG. 1 in more detail along with the operation, when the sample and hold signal arrives, the switch 6.7 closes, and the Lch and Rch analog signals a applied to the inputs of the amplifiers 1 and 3 and [are the amplifiers A capacitor 12.13 connected to the input of 2°4 is charged. In other words, it has been sampled.

When the sample hold signal @bIfi disappears, switch 6
．． 7 is asked and the sampled value is held in the capacitor 12.13. In other words, it is bolded. In FIG. 2, this operation timing is a
, l) , c and f, b, IJ. The output signals of amplifiers 2 and 4 are C and 9, respectively, which are signals obtained by sampling and holding a series of analog signals.

Next, this signal g is sampled and held again by a sample-and-hold signal whose phase is slightly different from that of the sample-and-hold signal.

This signal is 1, meaning that data signal 9 is delayed. The held signals of each of the switches 9.
10. Here, △10 converter 11
Which one is selected by switching signals d and d' to be converted alternately.

This converted signal e is recorded as a digital signal. The timing of this operation is shown in Fig. 2 d, h, and i.

It is expressed as d　I　,　e.

In this way, the analog signals of both the L and R channels are sampled and held simultaneously without being sampled alternately, and are alternately converted into digital signals and recorded in the PGM format.

According to the detailed description of the invention, the PGM recording and reproducing apparatus of the present invention has the following features:
The signals of both the first and second channels are simultaneously sampled and bolded, and one signal is delayed and digitally converted to AC, eliminating the need for two expensive analog/digital converters and achieving high fidelity. It is possible to provide an improved PCM0M recording and reproducing device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
This is the operation timing shown in the figure. 1-5...Amplifier, 6-10...Switch, 11.
・・A/D transformer, 12-14...Hold capacitor, 15°L channel signal input terminal, 16...
R channel signal input terminal agent Yoshihiro Morimoto

Claims (1)

[Claims] 1. A first sampling/holding device that samples and bolds the first analog signal; and a second sampling/holding device that samples and bolds the second analog signal at the same timing as the first sampling/holding device. a third sample-and-hold means for sampling and holding the output of the second sample-and-hold means at a timing different in phase from the timing; A/D means for switching the output of the sample/hold means and converting it into digital data.