JPH0445176Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a tape recording device for writing digital signal data consisting of "1" and "0" onto a cassette tape.

[Prior art]

An example of a conventional tape recording device will be described with reference to FIG.

In Figure 1, 1 is an input terminal for inputting digital signals of "1" and "0", and 2 is this input terminal 1.
A frequency modulation circuit that converts the digital signal input into the D flip-flop 2 into a frequency of n:1.
a, AND gates 2b and 2c, and an OR gate 2d. Reference numeral 3 designates an output terminal for supplying the output of the frequency modulation circuit 2 to an external cassette, 7 an AC conversion circuit, and 8 and 9 clock input terminals having a frequency of an (n is an integer) and a frequency of a.

In Fig. 2, the waveforms of the main parts for explaining the operation of Fig. 1 are represented by A, B, C, D, E, F.
In the figure, the generation points of each waveform A to F are similarly indicated by the symbols A to F.

Next, the operation of the circuit shown in FIG. 1 will be explained with reference to FIG. 2. The external signal input to input terminal 1 is “1” (high potential) as shown in waveform A in Figure 2.
This pulse is a combination of "0" (low potential) and "0" (low potential). Depending on the input, "1" or "0" may be continuous and there may be only a DC component, so the waveform cannot be directly recorded on a cassette tape via an external cassette.

Therefore, a frequency modulation circuit 2 is used to enable recording. In other words, as shown in waveform F in Figure 2, when the input terminal is "1", the frequency of waveform C is
By modulating to the frequency a of waveform D when it is an or "0", even if a waveform with continuous "1"s is input to input terminal 1, a continuous pulse of frequency an that is easy to record will be output to the cassette tape. In order to
Can be recorded on tape.

The frequency modulation circuit 2 is configured, for example, as shown in the dashed line in FIG.
Clock input terminal 8 of frequency an is connected to
The input signal from the input terminal 1 is synchronized with the frequency an, and the waveform B in FIG. 2 is output from the D flip-flop 2a, and its inverted output is also output. The AND gates 2b, 2c and the OR gate 2d output either the frequency an of the clock input terminal 8 or the signal of the frequency a of the clock input terminal 9, and when the output of the D flip-flop 2a is "1", the clock is output. Since the frequency an is output to the input terminal 8 and the frequency a is output to the clock input terminal 9 when the clock is "0", the waveform E shown in FIG. 2 becomes the output of the frequency modulation circuit 2. The AC converter circuit 7 converts it into waveform F in the figure, which is easy to record on tape.

With conventional tape recording devices, depending on the external cassette used, the frequency-modulated waveform F in Figure 2 may be recorded unstablely, and in extreme cases, the waveform F in Figure 2 may be completely reversed. As a result, it becomes impossible to demodulate to waveform A in FIG. 2, resulting in a read error.

[Summary of the idea]

This invention was made to eliminate the drawbacks of the conventional ones as described above, and by making it possible to select the recording polarity that is compatible with the external cassette being used using the operation keys, reading errors when reading the tape can be avoided. It provides a unique tape recording device.

[Example of idea]

An embodiment of this invention will be described based on the drawings.

Figure 3 shows an example of this invention.
is a polarity switching circuit that switches the polarity of the output signal of the frequency modulation circuit 2, and includes inverters 4a, 4b,
It is composed of AND gates 4c and 4d and an OR gate 4e. Reference numeral 5 denotes an operation key for controlling the polarity switching circuit 4, and 6 a display device for displaying the operating procedure of the operation key 5 in an interactive manner.The other features are the same as in FIG.

Next, the operation of the embodiment shown in FIG. 3 will be explained with reference to FIG. 4.

In FIG. 3, a digital signal inputted from an input terminal 1 is inputted to a frequency modulation circuit 2, and a signal modulated to n:1 as in the conventional example is outputted as a waveform F in FIG. 4.

The signal output from the frequency modulation circuit 2 is input to a polarity switching circuit 4, the polarity of which can be switched using an operation key 5. That is,
If the signal from the operation key 5 is "1", the waveform E shown in FIG. The respective waveforms F or F' are also output.

Further, the display device 6 is capable of displaying the operation instructions for the operation keys 5 in an interactive manner, and the operator can operate the device while looking at the display on the display device 6.

Figure 5 shows another embodiment of this invention.
10 is a polarity switching circuit, inverter 10a,
10b, 10c, and gates 10d, 10e,
It consists of 10f, 10g, and OR gates 10h, 10i. Other details are the same as in Figure 3.

FIG. 6 shows waveforms of essential parts for explaining the operation of the embodiment shown in FIG. In addition, waveforms B, C, D, E,
F' is indicated using the same reference numeral as the point of occurrence in FIG.

Next, the operation of the embodiment shown in FIG. 5 will be explained with reference to FIG. 6. For example, waveform C of 4KHz and 2K
A modulated signal of Hz waveform D is input to the clock input terminals 8 and 9 of the polarity switching circuit 10, and the polarity is selectively switched using the operation key 5. When the signal of the operation key 5 is "1", the clock input terminals 8 and 9 are input. Since the modulated signal enters the frequency modulation circuit 2, the waveform F shown in FIG. 6 is outputted to the output terminal 3. The signal of operation key 5 is “0”
Then, waveforms C' and D' enter the frequency modulation circuit 2, and the waveform F' shown in the figure is outputted from the output terminal 3.

In the above two embodiments, the operation instructions can be displayed in an interactive manner using the display device 6, but it goes without saying that the same effect can be achieved by using a simple changeover switch instead of an interactive method. do not have.

[Effect of idea]

As explained in detail above, this invention provides a frequency modulation circuit with a polarity switching circuit between the output terminals,
Furthermore, since an operation key is provided for switching this polarity switching circuit, the recording polarity suitable for the external cassette to be used can be selected with the operation key, which has the effect of eliminating read errors when reading the tape.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional example, and FIG. 2 is a signal waveform diagram showing the operation of the conventional example shown in FIG.
FIG. 3 is a block diagram showing an embodiment of this invention.
4 is a signal waveform diagram showing the operation of the embodiment of FIG. 3, FIG. 5 is a block diagram showing another embodiment of this invention, and FIG. 6 is a signal waveform diagram showing the operation of the embodiment of FIG. 5. It is a diagram. In the figure, 1 is an input terminal, 2 is a frequency modulation circuit, 2
a is a D flip-flop, 2b, 2c are AND gates, 2d is an OR gate, 3 is an output terminal, 4 is a polarity switching circuit, 4a, 4b are inverters, 4c, 4
d is an AND gate, 4e is an OR gate, 5 is an operation key, 6 is a display device, 7 is an AC exchange circuit, 8, 9
is the clock input terminal, 10 is the polarity switching circuit, 10
a, 10b, 10c are inverters, 10d, 10
e, 10f, 10g are and gates, 10h, 1
0i is an or gate. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] In a tape recording device that modulates an input signal of "1" or "0" to a frequency of 1:n by a frequency modulation circuit and outputs it as a recording signal from an output terminal, there is a polarity between the frequency modulation circuit and the output terminal. What is claimed is: 1. A tape recording device comprising a switching circuit, an operation key for switching the polarity switching circuit, and a display device for displaying operating instructions for the operation key in an interactive manner.