JP2002100997A - Fm transmitter and computer system provided with the fm transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a computer system, capable of reproducing sounds reproduced in a PC by sound quality/sound volume equivalent of the same as audio equipment, without using cables such as line cables. SOLUTION: This computer system is loaded with an FM transmitter provided with a hybrid IC structure, for which a digital circuit for frequency modulating audio signals, based on an inputted frequency and an analog circuit for transmitting the frequency modulated audio signals from an antenna to external audio equipment are integrated in hybrid manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a computer system having a built-in FM transmitter.

[0002]

2. Description of the Related Art A recent personal computer has a built-in sound mechanism such as a sound blaster. According to this sound mechanism, various sound reproductions such as reproduction of sound source data such as MP3 and sound input from a microphone are possible.

[0003] Normally, the sound reproduced by the sound mechanism is output from a speaker built in the PC. Also,
By connecting the audio output terminal of the PC and the audio device with a line cable or an optical cable, external output is also possible.

[0004]

However, when sound is output from a speaker built in the PC as described above, the number of speakers that can be built in is limited due to structural restrictions, and the sound quality is limited. Also, for the same reason, a PC cannot incorporate an amplifier device comparable to an audio device, and its sound volume is limited.

[0005] When a PC and an audio device are connected by a wire such as a line cable, the range of action and the like are restricted, which is inconvenient.

On the other hand, in the case of wireless transmission of audio data to audio equipment, simply installing a normal FM transmitter on a computer simply requires the FM transmitter.
The analog circuits of the transmitter can be significantly affected by noise from other digital circuits.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and even if audio reproduced by a PC is used, the same level as audio equipment can be obtained without using a wire such as a line cable. It is an object of the present invention to provide a computer system capable of reproducing sound quality and volume.

Another object of the present invention is to provide an FM transmitter which is not easily affected by noise from digital circuits even when the FM transmitter is mounted on a computer.

A first aspect of the present invention is a digital circuit for receiving a digital signal related to frequency control, and an analog circuit for frequency-modulating the audio signal based on the digital signal and performing transmission processing from an antenna to an external audio device. And a hybrid IC structure in which the hybrid transmitter and the receiver are hybrid-integrated.

According to the invention according to the first aspect, it is possible to realize an FM transmitter which is hardly affected by noise from a digital circuit even when the FM transmitter is mounted on a computer.

According to a second aspect of the present invention, there are provided a generating means for generating a digital signal for controlling a frequency, a generating means for generating an audio signal, a digital circuit for receiving a digital signal related to frequency control, and the digital circuit. FM having a hybrid IC structure in which an analog circuit for frequency-modulating the audio signal based on the signal and performing a transmission process from an antenna to an external audio device is integrated.
A computer system comprising a transmitter.

A third aspect of the present invention is a detecting means for detecting an unused frequency, a generating means for generating an audio signal, and an unused frequency detected by the detecting means. Means for selecting one frequency, generating a digital signal for setting the selected frequency, a digital circuit for receiving the digital signal, and frequency-modulating the audio signal based on the digital signal from an antenna. A computer system comprising an FM transmitter having a hybrid IC structure in which an analog circuit for performing transmission processing to an external audio device is hybridly integrated.

According to the inventions according to the second and third aspects,
It is possible to realize a computer system that can reproduce sound reproduced by a PC with the same sound quality and volume as audio equipment without using a wire such as a line cable.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, components having substantially the same functions and configurations are denoted by the same reference numerals, and repeated description will be made only when necessary.

FIG. 1 is a system block diagram of a computer having a display system according to the present invention.

In FIG. 1, a computer 1 has a CPU
Module 20, PCI bus 22, ISA bus 24, main memory 26, DVD decoder 28, I / O controller 30, PCI interface bridge 32, hard disk drive HDD 33, flash BIOS_ROM
34, graphic controller 36, EC / KBC3
8, LCD 42, FM transmitter 10, audio CODEC 50, mixer amplifier 52, built-in speaker 5
Four.

The CPU module 50 executes operation control and data processing of the entire computer system. The module 50 includes a CPU, a cache, and a main memory 5.
6 is mounted on it.

The main memory 56 functions as a main storage device of the computer system. The main memory 56 stores an operating system, an application program to be processed, data created based on the application program, and the like.

The I / O controller 62 is a gate array for controlling various I / O devices built in the main body of the computer 1, and various I / O connectors such as a serial port, a parallel port, and a USB port shown in FIG. Controls the input and output of the device connected to.

The PCI interface bridge (PCI
The I / F 66 is a gate array realized by a one-chip LSI. This PCI I / F 66 is a PCI
It has a bridge function for bidirectional connection between the bus 52 and the ISA bus 54 and a function for controlling the HDD 68.

The flash BIOS_ROM 70 is a rewritable flash memory, and stores a system BIOS. In addition, the system BIOS is
It is a systematization of function execution routines for accessing various hardware in the computer system.

The graphic controller 10 is a VGA
(Video Graphics Array) (640)
Dot × 480 lines), SVGA (800 dots × 6
00 line), XGA (1024 dots × 768 lines) and the like.

The LCD 42 is a display device for displaying an image based on a control signal from the graphic controller 36 and an image data signal.

The EC / KBC 38 is a characteristic part of the present invention, and is a controller that converts an input signal from the keyboard 40 into a bit string and transfers it to each control unit. Further, the EC / KBC 38 generates a control signal related to a frequency input from a keyboard 40, a mouse (not shown), or the like, and serially transfers the control signal to the FM transmitter 10 in a form described later.

The audio CODEC 50 is provided in the main memory 2
After subjecting the compressed data such as MP3 stored in No. 6 to expansion processing, it performs D / A conversion to generate an audio signal. This audio signal is transmitted to the F
The signal is output to the M transmitter 10 or the mixer amplifier 52.

The FM transmitter 10 has an audio C
The audio signal input from ODEC 50 is converted to EC / K
The frequency is modulated based on the frequency control signal from the BC 38, and transmitted from an antenna (not shown) to an external audio device. Specifically, based on the frequency control signal from the EC / KBC 38, the PLL in the FM transmitter
The oscillation circuit is controlled, a frequency setting voltage is generated from the oscillation circuit, and a frequency modulation signal is generated from the frequency modulation circuit.

The FM transmitter 10 is a characteristic part of the present invention, and has a hybrid integrated circuit structure (Hybr.) In which analog circuits and digital circuits are mixed and integrated.
IdIigrated Circuit structure (hereinafter, HIC structure).

FIG. 2 shows the HIC of the FM transmitter 10.
It is a figure for explaining a structure.

As shown in FIG. 2, the important points of the present FM transmitter 10 are a digital circuit for performing processing relating to a frequency control signal and an audio signal, and modulating a voice signal based on an external frequency control signal, and transmitting an external audio signal from an antenna. An HIC structure in which an analog circuit for performing transmission processing to a device is mixed. The reason for having this structure is as follows.

That is, when a device in which an analog circuit and a digital circuit are mixed is realized, the digital circuit acts as a noise source and affects the analog circuit. When an analog circuit is used as an FM transmitter as in this computer system, much of the noise becomes noise, and high-quality sound reproduction, which is one of the objects of the present invention, cannot be realized.

Therefore, in the present computer system, H
By using the FM transmitter 10 having the IC structure,
This solves the problem. That is, FM of HIC structure
According to the transmitter 10, the analog circuit is integrated with the minimum necessary digital circuit for the FM modulation of the audio signal, so that the influence of noise due to sound can be minimized.

Further, as shown in FIG. 2, the FM transmitter 10 has ten signal lines (CE signal line, CK signal line, DA signal line, Sound-L signal line, Sound signal line).
-A total of 10 R signal lines, analog power signal lines, main power signal lines, analog GND signal lines, GND signal lines, and antenna signal lines: where analog power signal lines and analog G
The ND signal line can be omitted as necessary. ) And are unitized.
The reason for having this structure is as follows.

That is, in general, an apparatus having an analog circuit requires adjustment between circuits at the time of manufacturing or shipping. Further, when a digital circuit and an analog circuit are mixed in one device, if the digital circuit and the analog circuit are individually laid out, there is a possibility that a product variation may occur, and it is difficult in terms of layout.

However, in the case of a unitized structure for the present FM transmitter 10, the adjustment or the like may be performed for each unit, so that the adjustment at the time of shipment or the like is unnecessary, and the manufacturing efficiency is reduced. It is possible to improve. In addition, it is possible to prevent product variations from the viewpoint of layout.

The mixer amplifier 52 has an audio COD
An amplifier that adjusts and mixes the signal from the EC 50 to generate a predetermined audio signal.

The built-in speaker 54 includes a mixer amplifier 52
Is a built-in speaker that outputs a sound based on a signal from the speaker.

Next, a process of transmitting an audio signal to an external audio device realized by the computer system will be described with reference to FIGS.

FIG. 3 is a diagram for explaining an audio signal transmission process to an external audio device.

First, the predetermined frequency value is set to K by the operator.
The data is input from B40 to the EC / KBC38. Alternatively, a preset frequency value is input to the EC / KBC 38 based on a predetermined sound reproduction operation. As shown in FIG.
The EC / KBC 38 generates a chip enable signal (C) for access control based on an input signal for a frequency value.
A hip enable signal: a CE signal, a clock signal (a clock signal: a CLK signal), and a data signal related to frequency setting (a DATA signal: a DA)
Signal) and serially transfers it to the FM transmitter 10. In this description, the CE signal, the CLK signal, and the DA signal are collectively referred to as a frequency control signal.

FIG. 4 is a diagram for explaining an example of a DA signal serially transferred from the EC / KBC 38 to the FM transmitter 10.

In FIG. 4, "D0 to D10" are data for setting a transmission frequency used for transmitting an audio signal to an external audio device, where D10 is the most significant bit and D0 is the least significant bit. "MON
“O” is data for switching operation between a stereo output and a monaural output. "PD0, PD1"
Is data for forcibly controlling the output of a charge pump that controls charging and discharging of a capacitor in the FM transmitter 10. “TEST” is, for example, LSI test data in which “T0” is always 1 and “T1” is always 0. The DA signal, the CE signal and the CK signal having such a configuration are serially transferred from the EC / KBC 38, and at the timing shown in FIG.
Input to 0.

Also, the Sound-L signal and the Sou signal are output from the audio CODEC 50 by a predetermined operation of the operator.
The nd-R signal is output to the FM transmitter 10.

The FM transmitter 1 has an audio CO
The audio signal input from the DEC 50 is converted to EC / KB
Frequency-modulating based on the frequency control signal from C38,
The audio data is transmitted as FM waves from an antenna to an external audio device as shown in FIG. The FM wave is received by an external audio device and output from a speaker of the audio device.

According to the configuration described above, the following effects can be obtained.

First, since sound can be output by an external audio device, high-quality sound reproduction with a large volume can be performed.

Second, since there is no need to connect to an external audio device via a wired cable, the range of action and the like are not restricted.

Third, the present computer system uses the HI
Since the FM transmitter having the C structure is used, the influence of sound due to noise can be minimized.

Fourth, since the FM transmitter has a unitized structure, adjustments and the like need only be performed for each unit, and the adjustment at the time of shipment or the like is unnecessary. As a result, it is possible to improve the manufacturing efficiency, and to prevent variations in products from the viewpoint of layout.

(Second Embodiment) In the first embodiment,
In this configuration, a frequency value used for modulation is determined by an input from an operator or the like. However, if the frequency value is
It is also conceivable that the frequency overlaps with a frequency used by FM radio broadcasting or the like.

Therefore, in the second embodiment, an example of a computer system which detects a vacant frequency during audio reproduction and automatically transmits the vacant frequency to an external audio device using any of the vacant frequencies will be described.

FIG. 6 shows a computer system according to the second embodiment. A characteristic point of this computer system is that a frequency search unit 60 is newly provided in addition to the components of the system shown in the first embodiment.

The frequency search section 60 has an FM wave receiving function, receives an FM wave, and detects a frequency used by FM radio broadcasting or the like. Then, the frequency search unit 52 sets a predetermined frequency value other than the used frequency, and outputs the frequency value to the EC / KBC 38.

According to such a configuration, interference with radio waves used for FM radio broadcasting and the like can be prevented, and sound can be reproduced with high sound quality.

Further, the operator can save time and effort in searching for an available frequency, thereby improving workability.

Although the present invention has been described based on the embodiments, various changes and modifications can be made by those skilled in the art within the scope of the concept of the present invention. It is understood that examples also fall within the scope of the present invention. For example, as shown in (1) and (2) below, various modifications can be made without changing the gist.

(1) In each of the above embodiments, if audio data is not transmitted as FM waves to an external audio device in order to save power consumption or prevent unexpected generation and reception of radio waves, Preferably, the power of the FM transmitter is turned off. For example, based on the end of music playback or the end of a music playback program, FM
A configuration in which the power of the transmitter is turned off is conceivable.

According to such a configuration, power consumption can be saved, and unexpected generation or reception of radio waves can be prevented.

(2) In each of the above embodiments, the previously used set frequency may be set as a default, and may be used continuously unless otherwise changed.

According to such a configuration, the trouble of setting the frequency for each sound reproduction can be omitted, and the operability can be improved.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made in the implementation stage without departing from the spirit of the invention. In addition, the embodiments may be implemented in appropriate combinations as much as possible, in which case the combined effects can be obtained. Furthermore, the above-described embodiment includes various stages of the invention, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effects described in the column of the effect of the invention can be solved. When at least one of the above is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.

[0061]

As described above, according to the present invention, there is provided a computer system capable of reproducing sound reproduced by a PC with the same sound quality and volume as audio equipment without using a wire such as a line cable. realizable. Further, according to the present invention, it is possible to realize an FM transmitter that is not easily affected by noise from a digital circuit even when the FM transmitter is mounted on a computer.

[Brief description of the drawings]

FIG. 1 is a system block diagram of a computer including a display system according to the present invention.

FIG. 2 is a diagram for explaining a HIC structure of the FM transmitter 10;

FIG. 3 is a diagram for explaining an audio signal transmission process to an external audio device;

FIG. 4 is a diagram for explaining an example of a DA signal serially transferred from the EC / KBC to the FM transmitter;

FIG. 5 is a diagram for explaining input of a CE signal, a CK signal, and a DA signal by the FM transmitter 10;

FIG. 6 shows a computer system according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Computer 10 ... FM transmitter 20 ... CPU module 22 ... PCI bus 24 ... ISA bus 26 ... Main memory 28 ... DVD decoder 30 ... I / O controller 32 ... PCI interface bridge 33 ... Hard disk drive HDD 34 ... Flash BIOS_ROM 36 ... Graphic Controller 38 EC / KBC 42 LCD 50 Audio CODEC 52 Mixer amplifier 54 Built-in speaker 60 Frequency search unit

Claims (8)

[Claims] A hybrid in which a digital circuit for receiving a digital signal related to frequency control and an analog circuit for frequency-modulating the audio signal based on the digital signal and performing a transmission process from an antenna to an external audio device are integrated. F characterized by having an IC structure
M transmitter. 2. The FM transmitter includes a signal line for inputting the digital signal, a signal line for inputting the audio signal, a signal line for power supply, a signal line for GND connection,
The FM transmitter according to claim 1, wherein the FM transmitter is a unit having a signal line for antenna output. 3. A generator for generating a digital signal for controlling a frequency, a generator for generating an audio signal, a digital circuit for receiving a digital signal related to frequency control, and the audio signal based on the digital signal. A FM transmitter having a hybrid IC structure obtained by hybrid-integrating an analog circuit for frequency-modulating the analog signal and performing a transmission process from an antenna to an external audio device. 4. The computer system according to claim 3, wherein said generating means serially transfers said digital signal to said FM transmitter. 5. A detecting means for detecting an unused frequency, and when a frequency corresponding to the digital signal is used, any of the unused frequencies detected by the detecting means. Means for selecting one frequency, wherein the FM transmitter modulates the audio signal to the selected frequency and transmits the modulated signal to an external audio device. 5. The computer system according to 3 or 4. 6. A detecting means for detecting an unused frequency, a generating means for generating an audio signal, and selecting any one of unused frequencies detected by the detecting means, Means for generating a digital signal for setting the selected frequency; a digital circuit for receiving the digital signal; and a process for transmitting a frequency from the antenna to an external audio device by frequency-modulating the audio signal based on the digital signal. And a FM transmitter having a hybrid IC structure in which an analog circuit for performing the above is hybrid-integrated. 7. The FM transmitter has a signal line for inputting the digital signal, a signal line for inputting the music signal, a signal line for power supply, a signal line for GND connection, and a signal line for antenna output. The computer system according to claim 3, wherein the computer system is a unit. 8. The computer system according to claim 3, wherein when the FM transmitter does not operate, power is not supplied to the FM transmitter.