JPS5930298A - Digital sound recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the reliability of a mobile communication device and make this device small-size, by storing a receiving signal as a digital signal and reproducing it in accordance with a reproducing request. CONSTITUTION:The signal received by an antenna 1 of the mobile communication device passes an A/D converting part 7 and is demodulated in a demodulating part 2 and is stored in a storage part 8 such as an IC memory or a magnetic bubble memory, which has not a mechanical operating part to be controlled, through a selective call signal detecting part 3 and a reproducing controlling part 6. Stored contents are outputted through a D/A converting part 9 and a speaker 5 or the like in accordance with a reproducing request. By the constitution using the storage part which has not the mechanical operating part and is made into an IC easily, this device is used as a mobile communication device, and the reliability of a digital sound recording and reproducing device is improved and this device is made small-size.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a digital recording/playback device for storing received signals as digital signals in a mobile communication device and playing back the stored contents upon a playback request.

Prior Art and Problems A system that calls and communicates with a desired mobile communication device mounted on a car or the like using a selective call signal has been widely adopted. Not only are they unable to respond even if they receive a message, but they are also unable to listen to the content of the communication. Therefore, it has been proposed to add a recording device to the mobile communication device and record the contents of the communication in the same way as an answering machine. As the recording device, a tape recorder is mainly used to record analog audio signals. However, since there are many mechanically moving parts, there is a high probability of failure and poor reliability.

Purpose of the Invention The present invention improves the reliability of mobile communication devices by converting received analog signals into digital signals and storing them using a storage unit such as an IC memory or magnetic bubble memory that does not have mechanical moving parts. The purpose is to Examples will be described in detail below.

Embodiment of the Invention The figure is a block diagram of the main part of the embodiment of the invention, and only shows the configuration of the receiving section. In the figure, 1 is an antenna, 2 is a demodulation section, 3 is a selective call signal detection section, 4 is a low frequency amplification section, 5 is a speaker, 6 is a reproduction control section, and 7 is a converter for converting an analog signal into a digital signal. AD converter, 8 is a storage unit without mechanically operating parts such as fc memory or magnetic bubble memory, 9 is a DA converter that converts the digital signals successively output from the storage unit 8 into analog signals, 1o is a selection call display unit , 11 are playback request terminals. Antenna l, demodulator 21
Selective call signal detection section 3. Low frequency amplification section 4 and speaker 5
1 constitutes a receiving section of a typical mobile communication device, and a demodulating section 2 is shown as including a mixer, an intermediate frequency amplifier, a detector, etc., and demodulates the signal received by the antenna 1. Detection is performed, and the output signal a is applied to the selective call signal detection section 3 and the AD conversion section 7. When the selective call signal detection unit 3 detects a selective call signal consisting of a tone signal or the like assigned to the mobile communication device, it applies the detection signal C to the reproduction control unit 6 and the detection signal C to the selective call display unit 10. It also adds the received signal to the low frequency amplification section 4. The following describes the operation when a user is selectively called and stores a received signal when the user leaves the mobile communication device.

When the selective calling signal detecting section 3 detects the selective calling signal as described above, the playback control section 6 adds the control signals e and f to the AD converting section 7 and the storage section 8, and outputs the digital data converted by the AD converting section 7. The signal d is stored in the storage section 8. In this case, it is preferable to convert the signal into a digital signal by compressing the amount of information such as ΔM, and by detecting a silent state, it is possible to increase the storage capacity by not storing the silent signal. Also, since the storage capacity of the storage unit 8 is limited,
The reproduction control section 6 has means for monitoring the amount of information stored in the storage section 8, and can use means such as time monitoring and address monitoring of the storage section 8. In the case of time monitoring, a time counting section activated by the detection signal G is provided, and by counting the time corresponding to the storage capacity of the storage section 8, a storage operation stop signal g is added to the storage section 8. It is possible to stop storing signals. Also, when the end of communication is detected by monitoring the received signal, a storage operation stop signal g is added to the storage unit 8, thereby preventing noise and the like from being stored.

Furthermore, by displaying the fact that a selective call has been made on the selective call display unit 10, when the operator returns to the mobile communication device, it is possible to identify the incoming call during an absence. Alternatively, it is also possible to display the received signal only when it is stored in the storage unit 8.

When the operator returns, when the operator applies a reproduction request signal p from a switch (not shown) to the reproduction request signal 1, the display on the selective call display section 10 is reset, and the reproduction control section 6 sends the reproduction control signal to the storage section 8. A control signal i is added to the DA converter 9.
Add. As a result, the previously stored contents are read out from the storage section 8, and the subsequent signal j is converted into an analog signal k by the DA conversion section 9 and applied to the low frequency amplification section 4.

Since the mobile communication device is also equipped with a transmitter, by detecting the selective call signal, it returns a recordable response signal and stores the contents of the call from the transmitting side that received the response signal. It can also be controlled to start. Furthermore, the storage operation can also be stopped using the output of the squelch circuit. Furthermore, by sending a call end signal from the transmitting side, the storage operation can be stopped upon detection of the call end signal. Also, as mentioned above, due to the storage capacity of the storage unit 8, there are cases where the storage operation stops during a call, but in that case, the sending side may be notified of the storage operation stoppage using a tone signal or the like. It is possible.

The control of whether or not to perform the above-mentioned storage operation is determined by whether or not the playback control unit 6 is operated, so when leaving the mobile communication device, the playback control unit 8 is enabled by a switch (not shown) or the like. That's a good thing. Therefore, in a normal case, even if a selective call is made, the speaker is driven and a call is made, but no storage operation is performed.

Furthermore, when a storage operation is being performed, the operation of the low frequency amplification section 4 can be stopped so that the speaker 5 is not driven.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention provides
A storage unit 8 that does not include mechanically operating parts such as a C memory or a magnetic bubble memory is provided, and the received signal is converted into a digital signal and stored, and the stored content is reproduced upon a reproduction request. Since there are no moving parts, reliability can be improved. In addition to the storage section 8, the AD conversion section 7. Since the DA converter 9 and the playback controller 6 can be integrated into an integrated circuit, they can be miniaturized.

Furthermore, the storage section 8 is configured to be removable, so that the stored contents can be saved and reproduced at any position.

[Brief explanation of the drawing]

The figure is a block diagram of main parts of an embodiment of the present invention. 1 is an antenna, 2 is an FFI adjustment section, 3 is a selective call signal detection section, 4 is a low frequency amplification section, 5 is a speaker, 6 is a reproduction control section, 7 is an AD conversion section, 8 is a storage section, 9 is a DA conversion section Part, 10
1 is a selective call display section, and 11 is a reproduction request terminal. Patent applicant Fujitsu Ltd. agent, patent attorney Gobe Tamamushi and 3 others

Claims (1)

[Claims] In a mobile communication device that performs communication by detecting a selective call signal in a selective call signal detection unit, an AD conversion unit that converts a received analog signal into a digital signal, and the AD conversion Digital converted by the department. a storage section that stores signals; a DA conversion section that reads out the stored contents of the storage section and converts it into an analog signal; and a digital signal converted by the AD conversion section when the selective call signal detection section detects a selective call signal. is stored in the storage unit,
Stopping the storage operation when a signal amount corresponding to the storage capacity of the storage unit is stored or upon completion of communication, and reading out the storage contents of the storage unit in response to a playback request, converting it into an analog signal by the DA conversion unit, and playing it back. A digital recording/playback device comprising: a playback control unit that performs operations.