CN101650935B - Optical drive sound producing device - Google Patents
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Abstract
一种光驱动发声装置。该发声装置包括:光源、光调制器、光放大器、传输光纤和发声薄膜。由光源产生的输出光,其强度经光调制器被音频信号调制,再经光放大器放大,入射到发声薄膜上,发声薄膜吸收入射光引起温度变化,使与发声薄膜靠近的空气层产生随光强度变化的热膨胀,引起空气介质密度变化,产生声音。本发明由光驱动方式产生的发声过程是一线性过程,原理上不会造成谐波失真,具有极高的发声保真度。与现有的电动发声装置相比,本发明所涉及的发声装置无需使用磁体和音圈,所以对外界磁场没有任何响应,可以在强电磁场存在的环境中正常工作;该发声装置无需使用金属或其它导体材料,发声所需要的能量可以由空间传输,或是使用光纤传输。
A light-driven sound-generating device. The sounding device includes: a light source, a light modulator, an optical amplifier, a transmission fiber and a sounding film. The intensity of the output light generated by the light source is modulated by the audio signal through the optical modulator, and then amplified by the optical amplifier. Thermal expansion with varying intensity, causing a change in the density of the air medium, produces sound. The sounding process generated by the optical driving method of the present invention is a linear process, which does not cause harmonic distortion in principle and has extremely high sounding fidelity. Compared with the existing electric sounding device, the sounding device involved in the present invention does not need to use magnets and voice coils, so it has no response to the external magnetic field and can work normally in the environment where strong electromagnetic fields exist; the sounding device does not need to use metal or other Conductor material, the energy required for sound can be transmitted through space, or through optical fiber transmission.
Description
【技术领域】: 【Technical field】:
本发明涉及一种发声装置,特别是一种由光信号驱动的发声装置,属于光学及发声技术领域。The invention relates to a sounding device, in particular to a sounding device driven by an optical signal, and belongs to the technical fields of optics and sounding.
【背景技术】: 【Background technique】:
现有的发声装置和器件,如扬声器(又称喇叭)及耳机,是一种将电能转换为声能的发声器件。虽然现有的扬声器种类很多,工作方式也不尽相同,但在发声原理上都是通过一定的振动部件产生机械振动,推动周围的空气,使空气介质产生波动从而实现电能到机械能再到声能的转换。扬声器可分为电动式扬声器、静电式扬声器,以及平板式扬声器等几种。其中,目前应用最为广泛的是电动式扬声器。常见的电动式扬声器一般由盆架、磁体、音圈、振动锥盆等组成。当音频电流经过音圈时,音圈在磁场的作用下产生振动。与音圈固定在一起的锥盆在振动时推动周围的空气运动,使扬声器周围的空气密度发生变化,而产生声音。描述扬声器性能的技术参数有多种,最主要的包括:有效频率范围、特性灵敏度、.额定最大正弦功率、额定谐波失真等。随着扬声器制作材料和工艺及技术的不断发展,各种功能和不同用途的扬声器产品都已被开发出来。尽管如此,现有的扬声器由其发声原理决定了它们都存在如下固有问题:Existing sound generating devices and devices, such as loudspeakers (also known as horns) and earphones, are sound generating devices that convert electrical energy into sound energy. Although there are many types of existing loudspeakers and their working methods are not the same, the principle of sound generation is to generate mechanical vibration through certain vibrating parts, push the surrounding air, and cause the air medium to fluctuate so as to realize electrical energy to mechanical energy and then to sound energy. conversion. Loudspeakers can be divided into dynamic loudspeakers, electrostatic loudspeakers, and flat-panel loudspeakers. Among them, the most widely used is the dynamic speaker. Common electrodynamic loudspeakers are generally composed of basin frames, magnets, voice coils, vibrating cones, etc. When the audio current passes through the voice coil, the voice coil vibrates under the action of the magnetic field. The cone fixed with the voice coil pushes the surrounding air to move when it vibrates, so that the air density around the speaker changes to produce sound. There are many technical parameters to describe the performance of loudspeakers, the most important ones include: effective frequency range, characteristic sensitivity, rated maximum sinusoidal power, rated harmonic distortion, etc. With the continuous development of loudspeaker production materials, processes and technologies, loudspeaker products with various functions and uses have been developed. Nevertheless, existing loudspeakers all have the following inherent problems determined by their sounding principles:
1.现有的扬声器均是由电流驱动,音圈容易受外界环境的干扰和影响。例如,在强电磁场存在的环境中,扬声器会受电磁场的干扰而出现杂音,严重的情况下甚至无法使用。1. Existing speakers are all driven by current, and the voice coil is easily disturbed and affected by the external environment. For example, in an environment where a strong electromagnetic field exists, the speaker will be disturbed by the electromagnetic field and cause noise, and in severe cases, it may even be unusable.
2.对现有的扬声器,如果要实现良好的发声效果,需要合理设计其结构并精心选取各种材料,还要考虑其电气性能,以及与音频放大器之间的匹配。2. For existing loudspeakers, if they want to achieve good sound effects, they need to design their structures reasonably and carefully select various materials, and also consider their electrical properties and matching with audio amplifiers.
3.现有的扬声器中电磁、机械运动等环节的非线性特性导致扬声器产生高次谐波,容易造成谐波失真,从而影响发声的保真度。3. The nonlinear characteristics of the electromagnetic and mechanical motions in the existing loudspeaker cause the loudspeaker to generate high-order harmonics, which easily cause harmonic distortion, thereby affecting the fidelity of sound production.
【发明内容】: 【Invention content】:
本发明目的是克服现有技术存在的上述不足,提供一种新型的发声装置,特别是一种由光信号驱动的发声装置。The object of the present invention is to overcome the above-mentioned shortcomings in the prior art, and provide a new type of sounding device, especially a sounding device driven by an optical signal.
该发声装置与现有的电动发声装置在驱动方式和发声机理上完全不同,它是以光的动量和能量驱动发声薄膜,或者产生机械振动,或者产生温度变化,或者是上述两种共同作用,推动周围的空气,使空气介质产生波动,实现由光能到声能的转换。与现有的电动发声装置相比,本发明所涉及的发声装置无需使用磁体和音圈,所以对外界磁场没有任何响应,可以在强电磁场存在的环境中正常工作;该发声装置无需使用金属或其它导体材料,发声所需要的能量可以由空间传输,或是使用光纤传输。The sounding device is completely different from the existing electric sounding device in terms of driving mode and sounding mechanism. It drives the sounding film with the momentum and energy of light, or produces mechanical vibration, or produces temperature change, or the above two combined effects, Push the surrounding air, make the air medium fluctuate, and realize the conversion from light energy to sound energy. Compared with the existing electric sounding device, the sounding device involved in the present invention does not need to use magnets and voice coils, so it has no response to the external magnetic field and can work normally in the environment where strong electromagnetic fields exist; the sounding device does not need to use metal or other Conductor material, the energy required for sound can be transmitted through space, or through optical fiber transmission.
本发明所涉及的光驱动发声装置的工作原理:频率为v的光子具有的能量为hv(h为普朗克常数)。当光入射到一非反光且非透明物体上,光的能量就会被吸收,导致其温度上升。而该物体又作为一热源,热量会向其周围介质传递。在周围介质为静止空气的情况下,热量将主要以热传导的方式由该物体向空气传递。如果该物体的热容量很小,则会将所吸收的光辐射能量以很高的效率传递给周围介质,即该物体的作用是实现由光能到热能的转换。如果入射光的光强是随时间变化的,该物体的温度也就随时间变化,热传导的结果是使其周围静止空气的密度产生随时间的变化,即产生声场并在空气中传播。The working principle of the light-driven sound generating device involved in the present invention: photons with frequency v have energy hv (h is Planck's constant). When light is incident on a non-reflective and non-transparent object, the energy of the light is absorbed, causing its temperature to rise. And the object acts as a heat source, and the heat will be transferred to its surrounding medium. In the case of still air as the surrounding medium, heat will be transferred from the object to the air mainly by heat conduction. If the heat capacity of the object is small, the absorbed light radiation energy will be transferred to the surrounding medium with high efficiency, that is, the function of the object is to realize the conversion from light energy to heat energy. If the intensity of the incident light changes with time, the temperature of the object also changes with time, and the result of heat conduction is that the density of the still air around it changes with time, that is, a sound field is generated and propagated in the air.
由于物体吸收光辐射所产生的热量与入射光强度成线性关系,由热传导造成的空气的密度变化也与入射光强度成线性关系,所以,由光驱动方式产生的发声过程是一线性过程,原理上不会造成谐波失真,具有极高的发声保真度。另一方面,该发声过程是由光能到热能再到声能的转换过程,在该转换过程中,没有涉及电信号,也无需使用导电材料。光信号的传导可以使用光纤完成,所以外界的电磁场不会对信号的传输产生任何干扰。Since the heat generated by an object absorbing light radiation is linearly related to the intensity of incident light, the density change of air caused by heat conduction is also linearly related to the intensity of incident light. Therefore, the sounding process generated by the light-driven method is a linear process. The principle It will not cause harmonic distortion and has extremely high sound fidelity. On the other hand, the sound generation process is a conversion process of light energy to heat energy and then to sound energy, in which no electrical signal is involved and no conductive material is used. The transmission of optical signals can be completed using optical fibers, so the external electromagnetic field will not cause any interference to the transmission of signals.
下面考虑光子动量的作用。频率为v的光子具有的动量为hv/C(C为光速),一般情况下,光子的动量极其微小,其作用可以忽略。当一能量为E的光脉冲以90度角入射到一物体上,设其表面反射率为R,其余均被物体所吸收,则物体由入射光脉冲获得的动量为(1+R)E/C。若入射光脉冲的宽度为Δt,则入射光脉冲对物体的作用力为(1+R)E/(CΔt)。所以对于峰值功率极高的超短激光脉冲,其对物体的作用力将是变得明显。如果该物体是厚度极薄(nm量级)的薄膜时,激光脉冲的作用将引起薄膜的振动,从而引起空气介质产生波动,产生声音。Next consider the role of photon momentum. The momentum of a photon with a frequency v is hv/C (C is the speed of light). In general, the momentum of a photon is extremely small, and its effect can be ignored. When a light pulse with energy E is incident on an object at an angle of 90 degrees, assuming its surface reflectivity is R, and the rest is absorbed by the object, the momentum obtained by the incident light pulse is (1+R)E/ c. If the width of the incident light pulse is Δt, then the force of the incident light pulse on the object is (1+R)E/(CΔt). Therefore, for ultrashort laser pulses with extremely high peak power, the force on objects will become obvious. If the object is a film with an extremely thin thickness (on the order of nm), the action of the laser pulse will cause the film to vibrate, which will cause the air medium to fluctuate and produce sound.
本发明提供的光驱动发声装置的具体结构依次包括:The specific structure of the light-driven sounding device provided by the present invention includes in turn:
光源:用于产生输出光;Light source: used to generate output light;
光调制器:根据输入的音频信号对光源产生的输出光强度进行调制;Light modulator: modulate the output light intensity generated by the light source according to the input audio signal;
光放大器:对光调制器调制后的光信号进行放大;Optical amplifier: amplifies the optical signal modulated by the optical modulator;
传输光纤:将光放大器放大后的光信号传输到发声薄膜;Transmission fiber: transmit the optical signal amplified by the optical amplifier to the sound-emitting film;
发声薄膜:经传输光纤传输的光信号入射到发声薄膜上,发声薄膜吸收入射光,光强度变化引起发声薄膜温度变化,使与发声薄膜靠近的空气层产生随光强度变化的热膨胀,引起空气介质密度变化,产生声音。Acoustic film: The optical signal transmitted by the transmission fiber is incident on the acoustic film, and the sound film absorbs the incident light. The change of light intensity causes the temperature change of the sound film, which makes the air layer close to the sound film thermally expand with the change of light intensity, causing the air medium Density changes, producing sound.
所述的光源可以为连续光源,也可以为脉冲光源。The light source can be a continuous light source or a pulsed light source.
具体讲,所述的光源可以是连续输出的光纤激光器,或脉冲输出的光纤激光器;或者是连续输出的半导体激光器,或脉冲输出的半导体激光器。Specifically, the light source may be a continuous output fiber laser or a pulse output fiber laser; or a continuous output semiconductor laser or a pulse output semiconductor laser.
所述的光放大器为光纤放大器。The optical amplifier is an optical fiber amplifier.
本发明提供的光驱动发声装置也可以采用电流驱动电路来实现,该装置依次包括:The light-driven sounding device provided by the present invention can also be realized by using a current drive circuit, and the device includes in turn:
电流驱动源:用于产生受音频信号调制的驱动电流;Current drive source: used to generate a drive current modulated by an audio signal;
半导体发光器件:用于产生光强随驱动电流变化的输出光;Semiconductor light-emitting device: used to generate output light whose light intensity changes with the driving current;
传输光纤:将光信号传输到发声薄膜;Transmission fiber: transmit the light signal to the sound-emitting film;
发声薄膜:经传输光纤传输的光信号入射到发声薄膜上,发声薄膜吸收入射光,光强度变化引起发声薄膜温度变化,使与发声薄膜靠近的空气层产生随光强度变化的热膨胀,引起空气介质密度变化,产生声音。Acoustic film: The optical signal transmitted by the transmission fiber is incident on the acoustic film, and the sound film absorbs the incident light. The change of light intensity causes the temperature change of the sound film, which makes the air layer close to the sound film thermally expand with the change of light intensity, causing the air medium Density changes, producing sound.
所述的半导体发光器件为半导体激光器;或半导体发光二极管。The semiconductor light emitting device is a semiconductor laser; or a semiconductor light emitting diode.
本发明的优点和积极效果:Advantage and positive effect of the present invention:
与现有的电动发声装置相比,本发明所涉及的发声装置无需使用磁体和音圈,所以对外界磁场没有任何响应,可以在强电磁场存在的环境中正常工作;该发声装置无需使用金属或其它导体材料,发声所需要的能量可以由空间传输,或是使用光纤传输。Compared with the existing electric sounding device, the sounding device involved in the present invention does not need to use magnets and voice coils, so it has no response to the external magnetic field and can work normally in the environment where strong electromagnetic fields exist; the sounding device does not need to use metal or other Conductor material, the energy required for sound can be transmitted through space, or through optical fiber transmission.
由光驱动方式产生的发声过程是一线性过程,原理上不会造成谐波失真,具有极高的发声保真度。The sounding process generated by the optical drive method is a linear process, which will not cause harmonic distortion in principle, and has extremely high sounding fidelity.
【附图说明】:[Description of drawings]:
图1为光调制光信号驱动发声装置结构示意图。FIG. 1 is a schematic structural diagram of an optically modulated optical signal driving a sounding device.
图中:101为光源;102为光强度调制器;103为电压放大器;104为输入音频信号;105为光纤放大器;106为传输光纤;107为发声体壳体;108为发声薄膜;109为声场。In the figure: 101 is a light source; 102 is a light intensity modulator; 103 is a voltage amplifier; 104 is an input audio signal; 105 is an optical fiber amplifier; 106 is a transmission optical fiber; .
图2为电调制光信号驱动发声装置结构示意图。Fig. 2 is a schematic diagram of the structure of the sound generating device driven by the electrical modulation optical signal.
图中:201为电流驱动源;202为光纤输出半导体发光器件;104为输入音频信号;106为传输光纤;107为发声体壳体;108为发声薄膜;109为声场。In the figure: 201 is the current drive source; 202 is the optical fiber output semiconductor light emitting device; 104 is the input audio signal; 106 is the transmission optical fiber; 107 is the shell of the sounding body; 108 is the sounding film; 109 is the sound field.
图3为强度调制的连续光信号示意图。图中:301为光强随时间变化曲线。Fig. 3 is a schematic diagram of a continuous optical signal with intensity modulation. In the figure: 301 is a curve of light intensity changing with time.
图4为强度调制的脉冲光信号示意图。图中:401为光强随时间变化曲线。Fig. 4 is a schematic diagram of an intensity-modulated pulsed light signal. In the figure: 401 is a curve of light intensity changing with time.
图5为在基片上制作的发声薄膜。图中:501为入射光;502为发声薄膜;503为基片。Fig. 5 is a sound-emitting film fabricated on a substrate. In the figure: 501 is the incident light; 502 is the sound-emitting film; 503 is the substrate.
【具体实施方式】:【Detailed ways】:
实施例1:Example 1:
如附图1所示,光源101采用德国Pilas,A.L.S.GmbH公司提供的PIL106半导体激光器,该半导体激光器即可以产生连续输出,也能产生脉冲输出,其输出模式由其电流控制单元EIG1000D设定。PIL106半导体激光器的输出波长为1060nm,连续输出功率大于400mW。光强度调制器102采用美国BATI提供的高速可变光纤衰减器(VOA)μVOA302。该VOA采用电光陶瓷作为开关材料,动态响应时间为1μS,对1060nm波长的插入损耗小于0.6dB。动态衰减范围25dB,反射损耗大于55dB。电光陶瓷具有很强的Kerr效应,电光系数比锂酸铌大2个数量级,半波电压远低于铌酸锂晶体。实验发现,对所选用的可变光纤衰减器,开关电压在100-150V范围内。光强度调制器102由电压放大器103驱动。电压放大器103采用美国BATI提供的电压放大电路,其输出信号电压幅度在50V-150V连续可调。电压放大器103的信号输入端接输入音频信号104。As shown in Figure 1, the
输入音频信号104经光强度调制器102加载到由半导体激光器输出的连续光的强度上,如附图3所示。再经光纤放大器105放大和传输光纤106传至发声装置壳体107,光信号由传输光纤106的输出端以一发散角经一空间传输距离入射到发声薄膜108上。发声装置壳体107是由塑料或是尼龙等非金属材料制成,发声薄膜108为厚度在亚微米的量级,材料为塑料或其它非金属材料。发声薄膜108固定在发声装置壳体107上。发声薄膜108的另一种方式是在基片上制作的发声薄膜,如附图5所示。The
强度受音频信号104调制的光信号被发声薄膜108吸收,转换为热能,使发声薄膜108的温度产生随音频信号104的变化,该温度变化引起发声薄膜108随音频信号104变化的热膨胀,致使其周围的空气密度发生改变,产生声场109,实现发声。The optical signal whose intensity is modulated by the
实施例2:Example 2:
如附图1所示,光源101采用PIL106半导体激光器,其输出模式由其电流控制单元EIG1000D设定为脉冲输出,脉冲宽度选为40ps,重复频率设定为1MHz。光强度调制器102采用美国BATI提供的高速可变光纤衰减器μVOA302,光纤放大器105为高峰值功率脉冲放大器。各种器件的连接方式与实施例1类似。不同的是序列光脉冲的脉冲能量被音频信号104经光强度调制,如附图4所示。发声薄膜108为厚度在亚微米量级的金箔。光脉冲入射到金箔表面,一部分光被反射,一部分被吸收。被吸收的光能转换为热能,形成与实施例1相同的发声过程。同时,光脉冲的动量使金箔产生振动,引起空气介质产生波动,产生声音。As shown in Figure 1, the
实施例3:Example 3:
如附图2所示,半导体发光器件202采用美国JDSU公司6397系列带尾纤输出的半导体激光器。该半导体激光器为多模连续输出,其连续输出波长为915nm,最大输出为6.5W,输出尾纤纤芯直径为105微米,驱动电流大于6A。电流驱动源201采用THORLABSLDC340半导体激光器电流驱动源,音频信号104接LDC340的调制输入(MOD IN)端。光强经调制的半导体激光器的输出由传输光纤106连接至发声体壳体107,入射到发声薄膜108上。强度受音频信号104调制的光信号被发声薄膜108吸收,转换为热能,使发声薄膜108的温度产生随音频信号104的变化,该温度变化引起发声薄膜108随音频信号104变化的热膨胀,致使其周围的空气密度发生改变,产生声场109,实现发声。As shown in FIG. 2 , the semiconductor
本领域的专业技术人员都清楚,本发明的思想可采用上面列举的具体实施方式以外的其它方式实现。It is clear to those skilled in the art that the idea of the present invention can be implemented in other ways than the specific implementations listed above.
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