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Receiver and infrared wireless-earphone

A receiver and wireless receiving technology, which is applied in the field of receivers to achieve pulse width stability, high-precision detection, and the effect of improving discomfort

Inactive Publication Date: 2007-06-13
SHARP KK +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0018] An object of the present invention is to provide a receiver which receives a 1-bit data string as a PDM signal and which can improve discomfort when noise due to a bit error rate occurs, and an infrared wireless earphone having the same.

Method used

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  • Receiver and infrared wireless-earphone
  • Receiver and infrared wireless-earphone
  • Receiver and infrared wireless-earphone

Examples

Experimental program
Comparison scheme
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Embodiment approach 1

[0069] One embodiment of the present invention will be described below based on FIGS. 1 to 7 .

[0070] FIG. 1 shows the configuration of an infrared communication receiver (receiver) 1 according to this embodiment. The infrared communication receiver 1 is, for example, a receiver of an infrared wireless earphone, and includes a receiving unit 2 , a speaker driving unit 3 and a speaker 4 . The output sound of the receiver is output in the form of headphones. Furthermore, the receiving section 2 has an error detecting section 20 .

[0071] A transmitter not shown in the figure transmits audio data composed of a 1-bit data string as a PDM signal by baseband transmission as a transmission signal. Here, it is assumed that the period (T) of the transmission signal is 500 nsec to 868 nsec (1.152 MHz to 2 MHz). This can be received by a medium-speed profile MIR (1.152 Mbps) or high-speed profile FIR (4 Mbps) device of an IrDA receiving device.

[0072] The receiving section 2 rec...

Embodiment approach 2

[0130] Another embodiment of the present invention will be described below using FIGS. 8 to 14 .

[0131] FIG. 8 shows the configuration of the error detection section 20 included in the infrared communication receiver 1 of the present embodiment. This error detection section 20 has a configuration in which a monostable multivibrator circuit 20c is added to the error detection section 20 of FIG. 2 .

[0132] The monostable multivibrator circuit 20c receives a received signal received by the infrared communication receiver 1 as an input signal in, and outputs an output signal H as an output. The output signal H is not only input to the integration circuit 20a, but also used as an audio signal for reproduction of the infrared communication receiver 1. FIG. In the present embodiment, bit errors are accurately detected by the integrating circuit 20a regardless of the distance between the infrared communication receiver 1 and the transmitter. In addition, in connection with this,...

Embodiment approach 3

[0154] Another embodiment of the present invention will be described below using FIGS. 12 to 14 .

[0155] This embodiment discloses a technique for making the pulse width at point H in FIG. 8 or 10 constant in Embodiments 1 and 2. FIG.

[0156] The pulse width Tpw of the output voltage at the point H is represented by Equation (3). Therefore, in order to make the pulse width Tpw constant, the values ​​of C3, Vref2, and I1 need to be constant. These fluctuation factors include temperature fluctuations and process fluctuations.

[0157] Generally, PTAT (proportional to absolute temperature, proportional to absolute temperature) current is prone to occur in monolithic ICs. Thus, first of all, a constant value independent of temperature can be obtained for the current I1. Fig. 12 shows an example of a PTAT current generating circuit.

[0158] This PTAT current generating circuit includes transistors QP1 to QP4 composed of PNP bipolar transistors, QN1 and QN2 composed of NPN bi...

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Abstract

A receiving section of an infrared receiver includes an error detecting section that detects, through an integrating circuit, a direct-current component of a 1-bit data sequence that is supplied in a form of a PDM signal. The direct-current component thus detected is compared with a reference voltage by the comparing circuit to determine whether the direct-current component is greater or smaller than the reference voltage, and a signal is outputted on the basis of a result of the comparison. When the direct-current component is decreased, it is determined that a bit error rate is greater. At this time, an output of sound from the infrared receiver is caused to become OFF.

Description

technical field [0001] The present invention relates to receivers, and more particularly to devices for wirelessly communicating voice data. Background technique [0002] In recent years, devices for digital audio signal processing have been extensively developed. Along with this, digital audio signal technology used for connection between devices has also been widely deployed. Digital audio data generally uses a PCM (Pulse Code Modulation: Pulse Code Modulation) format. In this case, a dedicated IC is required to convert PCM signals such as CD / MD / DVD into PDM modulated signals. For example, in Patent Document 1, it is proposed to transmit a 1-bit data string modulated by PDM (Pulse Density Modulation: Pulse Density Modulation) when an infrared communication device of the IrDA (Infrared Data Association) standard performs voice data communication. way etc. [0003] Fig. 15 shows a block diagram of a conventional infrared communication receiving device. The infrared comm...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L25/02H04L1/20H04B10/08H04B1/10H04B10/07H04B10/11H04B10/112H04B10/118H04B10/2507H04B10/524
CPCH04R3/00H04R2420/07H04B10/1149
Inventor 井上高广松谷康之石原隆子
Owner SHARP KK