JPH03237497A - Recording and playback device - Google Patents

Abstract

PURPOSE:To reduce the size and weight of the recording and reproducing device and to improve the operability of the device by storing a recording time signal indicating recording time obtained based upon an output from a clock circuit together with a signal obtained by digitizing a voice in a semiconductor storage device a the time of recording, and at the time of reproducing, reading out the stored signal and reproducing the signal as a voice. CONSTITUTION:The address of a memory 1 is determined by an address counter 8 and a clock signal CL is used as the sampling clock of an A/D converter 4 and a D/A converter 5 and controls the data I/O of the memory 1 as the clock of the counter 8 synchronously with the two converters. A sound signal inputted from a microphone 2 is amplified by an amplifier 3 and digitized by the A/D converter 4 and the digital signal is stored and recorded in the memory 1. In the case of reproducing the stored signal, the data outputted from the memory 1 are converted into an analog sound signal through the D/A converter 5 and a speaker 7 is driven through an amplifier 6. Since the semiconductor memory isused instead of a magnetic tape, the size and weight of the device can be reduced and the time up to the start of reproduicng can be shortened.

Description

[Detailed description of the invention] The present invention relates to a recording/playback device having an audio storage function.

Conventional recording and reproducing devices generally use a magnetic tape recording method. On the other hand, as calculators, radios, etc. have become smaller in size, there has been an increasing demand for smaller audio recording devices, ie, tape recorders. However, traditional tape recording methods are not compatible with small size. First, advanced mechanisms such as motors that control the rotation of the tape are difficult to reduce in size and weight. Second, driving mechanisms such as motor relays consumes a considerable amount of power, and the lifespan of batteries, which are the power source for portable devices, is too short, reducing commercial value. 3
One of the reasons is that miniaturization places a burden on the mechanism, and at the same time, tapes are unavoidably miniaturized, resulting in poor playback audio quality. Fourth, it takes time to search because the tape is fast-forwarding and reversing.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an object of the present invention is to provide a recording/playback device that uses semiconductor memory instead of conventional magnetic tape, is small, lightweight, and takes a short time to start playback. do.

Another purpose is to display the recording time on the display when the audio is played back.

The present invention provides A for converting an audio signal into a digital signal.
a /D converter, a clock circuit, a semiconductor storage device that stores the digital signal during recording and also stores a recording time signal indicating the recording time obtained based on the output from the clock circuit, and the semiconductor storage device during playback. an address control device that controls reading of the digital signal and the recording time signal stored in the semiconductor storage device; a D/A converter that converts the digital signal read from the semiconductor storage device into an analog signal; A speaker that reproduces the analog signal converted by the converter as audio, and a display device that displays the recording time of the reproduced audio based on the recording time signal read from the semiconductor storage device during reproduction. shall be.

Hereinafter, the present invention will be described in detail based on Examples.

The bronc diagram in FIG. 1 shows the gist of the present invention, and 1 is a memory area. The address of this memory is determined by an address counter 8. Clock signal CL is supplied to A/D converter 4 and D/A converter 5
At the same time, it serves as a sampling clock for the address counter and controls data input/output of the memory in synchronization with the two converters. The audio signal input from the microphone 2 is amplified by the amplifier 3, further converted into a digital signal by the A/D converter 4, and stored in the memory 1. This is the recording operation. For reproduction, the data output from the memory is converted into an analog audio signal by the D/A converter 5, and the speaker 7 is driven by the amplifier 6. Also 110
The boat 10 receives signals from the keyboard or the switch 9 and has the role of controlling recording, playback, and searching as well as outputting an address display to the display 11. keyboard 9
When an address is specified by , the specified address is immediately called up, and there is no need for fast forward or reverse functions like with a tape, so there is no waiting time. Here, if the address counter 8 is a microcomputer with a built-in program, more advanced functions will be possible. For example, automatic recording, playback, repeat, automatic search, etc. Further, since the I10 port IO in FIG. 1 has a register function, it can hold the output from the timer circuit based on a common clock signal, and can notify the time on the display. That is, the clock function can be shared, and the recording time and time can be simultaneously stored in the memory and displayed on the display during playback.

FIG. 2 shows one specific example of the memory of the present invention. Audio storage needs to be non-volatile in nature.

When such a CMOS memory is used, the quiescent current is very small, so non-volatility can be achieved with extremely low power consumption. Also, the operating power and addressing frequency are at most 1 OKH.
Since it is about z, it is less than 10μ8 at 15V. BZT
, NTT is a data human output line, A is an address line, and transistors 14, 15 and 171 roll. 12.13
constitutes an inverter clip-flop for storage.

FIG. 3 shows another example of a memory as an audio storage medium. A floating gate 16 is embedded in an insulating film 17.

When a voltage higher than that at which avalanche breakdown occurs with respect to the substrate N- is applied to the drain P°, high-energy electrons cross the gate film barrier and are injected into the floating gate, where they remain for more than 10 years. Therefore, the channel resistance of the transistor is determined by the amount of injected charge.

Figure 4 shows this relationship. That is, avalanche voltage Vav
The above is applied to the drain to control the channel resistance Reff. The injection time is approximately 100 μsec. Further, Vav can be up to about 5■.

Figure 5 shows audio recording using this nonvolatile memory cell.
An example of the configuration of a playback device is shown. Audio input Aln is amplifier 18
The signal is amplified by the buffer 19, and the bias is matched with that of the memory cell, and then input to the cell. The cell 22 is composed of a memory transistor 23 and an address control transistor 24, and is selected by an address signal A'. E is a charge erasing signal. The playback is
The transistor 25 is turned on by OE, and the load resistance Re
The amplifier 20 directly detects the channel resistance Reff by
output from the speaker 21 via.

The memory transistor used here does not have to be of the floating gate (FAMO3) type, but may be of any non-volatile type, such as tunnel MNO3. In the embodiment mentioned here, the memory is directly accessed by an analog signal, and the A/D converter 4 and D/A converter 5 in FIG. 1 can be omitted. There is no problem in simply replacing it with 1-bit non-volatile memory.

The present invention uses a semiconductor as a memory element, and the required capacity is 16 Kbit/sec for a digital memory method and 2 Kbit/sec for an analog memory method, for example, 2 Kbit/sec.
Using a 256 Kbit/chip non-volatile memory using a μm pattern, it is possible to record audio with a storage time of 15 minutes using 6 chips. This is so compact that it can even fit into a wristwatch. Therefore, the size can be sufficiently reduced and the weight can be significantly reduced.

Furthermore, the power consumption during recording and playback is so low that even ordinary silver batteries can be used, since there is no motor power at all.

Furthermore, the control IC used in the present invention becomes more convenient because it has multiple functions such as a calculator and a clock. For example, the memory can be shared not only as an audio storage area but also as a time, time storage, calculation step or result storage. Furthermore, if the controller is a microcomputer, functions such as a clock, calculator, and voice storage can be controlled by a series of software, making it possible to integrate them into the same chip. In addition, the display body is the display of the voice address,
The display of the clock and the display amount of the calculator can be shared, making it possible to create a compact portable information device with high commercial value by using all semiconductors.

As described above, according to the present invention, the recording time signal indicating the recording time obtained based on the output from the clock circuit is stored in the semiconductor storage device together with the signal obtained by digitizing the audio at the time of recording, and is read out at the time of playback and digitized. By D/A converting the signal and reproducing it as audio, and displaying the recording time signal as the recording time on a display device, it is possible to provide a recording and reproducing device that is small, lightweight, and easy to operate. In addition, when playing,
The user can not only listen to the reproduced sound, but also know at what time the recorded sound was recorded based on the displayed recording time.

FIG. 3 is a diagram showing an example of a floating gate type (FAMO3) nonvolatile storage transistor.

Figure 4 shows the drain applied voltage and channel equivalent resistance Rerf.
Relationship diagram.

FIG. 5 is a diagram showing an example of the configuration of an audio recording/reproducing device using nonvolatile memory cells 22. 21 is a speaker.

that's all

Claims (1)

[Claims] An A/D converter that converts an audio signal into a digital signal, a clock circuit, and a semiconductor memory that stores the digital signal during recording and also stores a recording time signal indicating the recording time obtained based on the output from the clock circuit. an address control device that controls reading of the digital signal and the recording time signal stored in the semiconductor storage device during playback; and D that converts the digital signal read from the semiconductor storage device into an analog signal. a /A converter, a speaker for reproducing the analog signal converted by the D/A converter as audio, and displaying the recording time of the reproduced audio based on the recording time signal read from the semiconductor storage device during reproduction. A recording/playback device comprising: a display device for displaying images;