US2528728A - Sound-receiving method and system - Google Patents

Description

Nov. 7, 1950 R. H. RINES SOUND RECEIVING METHOD AND SYSTEM Filed Aug. 3, 1945 OSCILLATOR Patented Nov. 1, 1950 UNITED STATES PATENT OFFICE SOUND-RECEIVING METHOD AND SYSTEM Robert Harvey Rincs, Brookline, Mass.

Application August 3, 1945, Serial No. 608,781

33 Claims.

The present invention relates to electric systems, and more particularly to receiving systems using sound waves as the agency of communication. The term soundwill be employed hereinafter, in the specification and the claims, to include not only the audible part of the sound spectrum, but also, and more particularly, the ultrasonic spectrum, and to include allkinds of elastic vibrations.

An object of the invention is to provide a new and improved sound-receiving system.

Another object is to provide a novel combined sound-and-television system.

Another object of the present invention is to provide a. new sound-locator system for both detecting the presence of a body and producing a visible likeness thereof.

Other and further objects will be explained hereinafter and will be more particularly pointed out in the appended claims. 7

The invention will now be more fully explained in connection with the accompanying drawings, in which Fig. 1 is a diagrammatic view of circuits and apparatus arranged and constructed in accordance with a preferred embodiment thereof; Fig. 2 is an enlarged fragmentary view of a modification; and Fig. 3 is a view of a modifled receiving apparatus.

A directive ultrasonic transmitter (not shown) may be employed to direct ultrasonic waves to-. ward object 25, illustrated as an underwater submarine. The sound waves are reflected and scattered from the surface of the object 25 toward a sound-receiving station. The invention is operable also with objects 25 that emit, as well as reflect or scatter, sound waves.

At the receiving station, the sound waves thus reflected and scattered from the object 25 may be focused, converged or impressed by a sound lens 21 upon a bank or array 26, comprising a plurality of sound-receiving pick-up unit elements vibratory in response to the sound energy impinging thereon. The sound lens 21 may be replaced by any other type of well-known lens, mirror or other directive system for focusing the sound waves scattered and reflected from the object 25 on the bank or array 26 of pick-up elements. The sound lens may, for example, be constituted of a collodion balloon filled with carbon dioxide or sulphur dioxide; or any other substance for refracting the sound waves.

The vibratory pick-up elements of the bank or array 26 are shown as piezo-electric receiver elements constituted, for example, of crystals of Rochelle salt, di-hydrogen potassium phosphate,

or any other suitable substance, including quartz. The front surface of each crystal element projects forward in the direction of the incoming sound waves.

The crystal pick-up units are shown arranged in the form of rows and columns, in the proximity of the focal plane of the lens 21. The first or uppermost row of the bank is illustrated as comprising the crystals I, 3, 5, l, and 9, shown as equally spaced horizontally. The second row from the top is shown constituted of similarly disposed crystals, respectively disposed directly below the corresponding crystals of the first row; several of these are illustrated at H, and IS. The third or next-lower row is similarly constituted, and so on. Though only a small number of pick-up units is shown in each row, and though only two rows are shown, this is merely for illustrative purposes, in order not to confuse the disclosure. It will be understood that, in practice, a large number of pick-up units will be employed-in each row.

The crystal elements 6, H, etc., are shown arranged vertically in the first or left-hand column. The crystal elements 3, 13, etc., are disposed in the second column from the left, and so on. There may, or may not, be as many columns as there are pick-up units in each row. Though each column is shown as comprising only a few pick-up units, this is again in order not to complicate the drawing.

The pick-up units will, of course, all receive the reflected or scattered sound waves through the lens 21 simultaneously. There will be focused on each pick-up unit a sound-wave intensity corresponding to the intensity of the sound energy reflected or scattered from a corresponding area of the object 25. Voltages will thus be produced across the pick-up elements corresponding to the difierent field strengths of sound-wave energy thus received by them, and proportional to the intensity of the sound-wave energy reflected or scattered or otherwise emanating from the various parts of the object 25 and converged upon the array 26 of pick-up elements by the lens 21. The sound lens 21 or its equivalent will thus focus upon the array 26 the sound waves reflected or scattered from the various parts of the object 25 in various energy strengths dependent on the reflecting properties of the component parts of the object 25, thus to produce a faithful sound image of this distribution of the sound waves in approximately the focal plane of the lens 21. The same result may be attained, as first pointed out by Lord Rayleigh, with the aid of a circular disc (not shown) the sound waves from the object will become diffracted about the periphery of the 'disc to produce a similar sou'nd image of the object 25.

It has heretofore been proposed to convert a sound-energy picture of this character into a visible-picture likeness 31. According to a feature of the present invention, however, improved results are obtained with the aid of light-modulation means, preferably employing polarized light, responsive to sound vibrations. A further feature resides in the enhancement of the vibrations in response to sound waves of the mechanically vibratory elements cooperative with the light-modulation means through the use of oscillating and other electric circuits.

The mechanically vibratory crystals I, 3, 5, etc., may be held in metallic crystal holders or between crystal electrodes, as shown. One of each pair of the crystal electrodes is shown grounded. The other crystal electrode of each crystal is connected to ground through an isolating impedance and a battery 23. The crystal I is illustrated as disposed between a lower metal grounded electrode and an upper metal electrode that is connected to the ground through an isolating impedance 3I and the battery 23. The crystal 3 is similarly connected between a lower metal grounded electrode and an upper electrode that is grounded through an impedance 33 and the battery 23. The impedances through which the upper electrodes of the crystals 5, 1, 9, II, and I3 are similarly grounded are respectively shown at 36, 38, 40, 43, and 4|.

The crystals, with their holders or electrodes, are respectively disposed in sound cells of such nature that, when the crystals are excited, the sound waves emitted thereby will travel in the corresponding cells to set up standing waves therein. The cells may, for example, be liquidcontaining, preferably completely closed cells or chambers adapted to be excited at ultrasonic frequencies. The cells are shown arranged in rows and columns to correspond to the rows and columns along which the crystals are disposed. The crystals I, 3, 5, l, 9, II, and I3 are illustrated as disposed in the respective cells 2, 4, 6, 8, I0, I2, and I4.

The cells need be only a few wave lengths in height. For ultrasonic waves of one megacycle frequency in water, for example, a cell of a few millimeters dimension would have a height of 100 wave lengths.

I havesuccessfully used solid ultrasonic cells of glass and fused quartz, such as is shown at 42 in Fig. 3, subjected to sound waves by a crystal which is placed in contact with the solid block.

Upon receipt of the sound waves from the object 25 by the piezo-electric crystals, they are caused to change their dimensions mechanically in response to the pressure of the sound waves upon them, and this change in pressure may be utilized to effect a light modulation, as will presently be described.

A more sensitive response may be obtained, however, with the aid of the battery 23; the change in dimension of the crystals will thereby result in modulating the electric energy or voltage produced by the battery across the crystal electrodes, and this change in voltagewill be accompanied by an enhanced or intensified mechanical change.

A still more sensitive, intensified and enhanced effect may be produced by replacing the battery by an oscillator or oscillators. Two such oscillators 5I and 53 are illustrated in Fig. 2, respectively connected to the upper electrodes of the crystals I and 3. The forced resonant vibrations produced in response to the voltage oscillations of the oscillator or oscillators will be modulated in response to the pressure of the sound waves upon the crystals, producing the cumulative conversion of mechanical vibrations into electric energy and electric energy into enhanced mechanical vibrations. A preferred light-modulating system will now be described.

A light source 20 may be collimated by a lens system 22 and polarized by, for example, a Nicol prism or other polarizing material 24. The polarized light is directed toward the mechanically vibratory medium comprising the cells of the array 28, so that successive transverse portions of the light beam illuminate the successively disposed cells. After passing through the cells, the polarized light is focused by a lens system 28 upon the screen 30. An analyser comprising a crossed Nicol prism 2I, and interposed between the lens system 28 and the screen 30, is oriented at right angles to the orientation of the polarizer 24. Normally, therefore, no light reaches the screen 30.

The battery 23 impresses an initial charge on the crystals through their respective isolating impedances. Owing to the sound-wave distribution from the object 25 focused on the bank of crystals by the lens'or lens-substitute 21, how ever, diiferent intensities of sound waves are impressed upon the various crystals, with the result that the cells are subjected to different strengths of standing sound waves, corresponding to the distribution of sound from the object 25.

The polarized light sent through the non-excited liquid or solid ultrasonic cells is analyzed or extinguished by the analyzer 2 I. Upon the excitation of the mechanically vibratory medium comprising the cells, and consequent modification of the refractive index, known as birefringence, of the various parts of the cells, the polarized light passing through the cells becomes depolarized thereby to penetrate the analyzer 2I in intensities related to the intensities of the ultrasonic waves in the cells. The light through the respective cells, therefore, passes the analyzer H with intensities corresponding to the sound-energy distribution from the object 25.

successively disposed areas, portions or parts of the screen 30, that correspond to the similarly disposed pick-up elements, will be energized to illuminate them with an intensity modulation corresponding to the sound-energy distribution upon the corresponding receiving elements.

The illumination resulting from the intensity modulation on the screen 30 will be such that the intensity of illumination of parts of the screen 30 corresponding to parts of the crystal bank 26 will correspond to the sound-wave image on the rows and columns of the bank 26-; this sound-wave image, in turn, corresponding to correspondingly disposed parts of the object 25.

The sound waves received by the crystal units along the successive rows and columns will thus become converted into successive portions of the visual likeness at portions of the screen 30 corresponding to the correspondingly disposed rows and columns of the pick-up units. The visualpicture likeness 31 of the object 25 thus produced on the screen 30 will accordingly correspond to the sound-energy picture on the array 26 of pick-up elements which, in turn, corresponds to the actual object 25.

The crystals of the bank 26 may be wafer thin, in order to make possible the use of a sufiiciently large number of them in the array 26 to provide for good definition. The frequency of the sound waves, for example, may be megacycles, corresponding to a wave-length of approximately 5x10" feet, in water.

Individual light sources (not shown) may be employed in connection with the respective cells and other light-modulation systems may be substituted for the modulation system shown.

Other vibrators than crystals may also be employed in accordance with the present invention; for example, magnetostrictive or magneto-.

motive vibrators,

- Although the invention has been described in connection with pick-up elements arranged in rows and columns, it will be understood that this is not essential, for other arrangements are also possible. Pick-up elements arranged along concentric circles covering the field, or along a continuous spiral, will also serve.

Further modifications will occur to persons skilled in the art, and all such are considered to fall within the spirit and scope of the invention, as defined in the appended claims.

What is claimed is:

1. A method of the character described that comprises receiving sound waves from an object through the water, producing a light beam, and

varying the intensity of successive transverse portions of the light beam in accordance with the intensity of the sound waves received from corresponding portions of the object to produce a likeness of the object.

2. An electric system having, in combination, means for receiving sound waves, means for converging sound waves from an object upon the receiving means, means for producing a polarized light beam, and means interposed in the path of the successive transverse portions of the polarized light beam and cooperative with the receiving means for producing a likeness of the object.

3. An electric system having, in combination, piezo-electric-receiving means for receiving sound waves, means for converging sound waves from an object upon the receiving means, and polarized-light means cooperative with the receiving means for producing a likeness of the object.

4. An electric system ,having, in combination, piezo-electric receiving means for receiving sound waves, means for converging sound waves from an object upon the receiving means, means for producing a light beam, and light-modulation means interposed in the path of the successive transverse portions of the light beam and cooperative with the receiving means for producing a likeness of the object.

5. An electric system having, in combination, means for producing a light beam, light-modulation means interposed in the path of the successive transverse portions of the light beam for receiving sound waves from an object, and means cooperative with the receiving means for producing a likeness of the object.

6. A sound system having, in combination, means for producing a light beam, a sound receiver, a sound lens for focusing sound waves from an object upon the receiver, and transparent light-modulation means interposed in the path of the successive transverse portions of the light beam and cooperative with the receiver for producing a likeness of the object.

7. An electric system having, in combination, a bank of piezo-electric sound-receiving elements for simultaneously receiving adjacent portions of a distribution of sound waves from an object, means connected with the receiving elements for intensifying the sound waves received by the elements, and means connected with the intensifying means for simultaneously producing corresponding adjacent portions of a likeness'oi' the object.

8. An electric system having, in combination, a bank of sound-receiving elements for receiving sound waves from an object, means connected with the receiving elements for intensifying the sound waves received by the elements, means for producing a light beam, and light-modulation means interposed in the path oi the light beam and acting with the sound-receiving elements for producing a likeness of the object.

9. An electric system having, in combination, a sound lens, and a plurality of light-modulation sound receiving cells disposed in the focal plane of the sound lens and means for sending a light beam through the plurality of cells.

10. An electric system having, in combination, a plurarity of cells, a plurality of sound-receiving elements, one connected to each of the cells, means for impressing sound waves upon the elements to convert the impressed waves into sound disturbances in the cells, a screen successively disposed areas of which correspond to the successively disposed elements, means for sending a polarized light beam through the sound cells to illuminate the screen, and means for analyzing the light beam in order to detect variations in the polarized-light illumination of the said areas of the screen in accordance with the sound received by the corresponding elements.

11. A method of the character described that comprises passing a light beam along a predetermined direction, independently modulating the successive transverse portions of the light beam in accordance with sound waves from an object while the successive transverse portions of the light beam retain their predetermined direction, and producing a likeness of the object in accordance with the modulation of the light beam.

12. A method of the character described that comprises polarizing successive transverse portions of a light beam, modulating the successive transverse portions of the polarized light beam in accordance with sound waves received from an object, and causing the modulation of the successive portions of the polarized light beam to produce a likeness of the object.

13. An electric system having, in combination, a mechanically vibratory medium, means mechanically vibratory in response to sound waves and mechanically connected to the medium, means for passing successive transverse portions of a light beam to corresponding successive portions of the medium, means for focusing sound waves from an object upon the mechanically vibratory means to vibrate the successive portions of the medium in accordance with the focused sound waves, thereby to effect modulation of the successive transverse portions of the light beam in accordance with the focused sound waves, means responsive to the vibrations of the mechanically vibratory means for impressing a voltage upon the vibratory means in order to enhance the vibrations of the vibratory means, thereby to enhance the vibrations of the successive portions of the medium and correspondingly to enhance the modulation of the correspondingsuccessive transverse portions of the light beam, and means controlled in accordance with the modulation of the successive transverse portions of the light beam for producing a likeness of the object.

14. An electric system having, in combination, means mechanically vibratory in response to sound waves, means for focusing sound waves from an object upon the mechanically vibratory means, means responsive to the mechanical vibrations of the mechanically vibratory means and controlled in accordance with the intensity of the sound waves for impressing a voltage upon the mechanically vibratory means in order to enhance the mechanical vibrations of the mechanically vibratory means, and means controlled in accordance with the enhanced mechanical vibrations of the mechanical vibratory means for producing a likeness of the object.

15. 'An electric system having, in combination, completely closed cell means mechanically vibratory to set up standing waves therein, means mechanically vibratory in response to sound waves and mechanically connected to the cell means to vibrate the cell means, means for focusing sound waves from an object upon the mechanically vibratory means to set up in the cell means standing waves corresponding to the distribution of sound energy in the focused sound waves, and means controlled in accordance with the standing waves to produce a likeness of the object.

16. An electric system having, in combination,

a medium that is mechanically vibratory in response to sound waves, piezo-electric means connected to the medium to vibrate the medium, means for focusing sound waves from an object upon the piezo-electric means to vibrate the medium in accordance with the distribution of the energy in the focused sound waves, and means controlled in accordance with the vibration of the medium for producing a likeness of the object.

17. An electric system having, in combination, a medium that is mechanically vibratory in response to sound Waves, piezo-electric means connected to the medium to vibrate the medium, means for focusing sound waves from an object upon the piezo-electric means to vibrate the medium in accordance with the distribution of the energy in the focused sound waves, and lightmodulation means controlled in accordance with the vibration of the medium for producing a likeness of the object.

18. An electric system having, in combination, a medium mechanically vibratory in response to sound waves, means for polarizing successive transverse portions of a light beam, means for passing the successive transverse portions of the polarized light beam to corresponding successive portions of the medium, means for focusing sound waves from an object upon the successive portions of the medium to cause the resulting mechanical vibrations of the successive portions of the medium to effect modulation of the corresponding successive transverse portions of the polarized light beam in accordance with the focused sound waves, and means controlled in accordance with the modulation of the successive transverse portions of the polarized light beam for producing a likeness of the object.

19. An electric system having, in combination, a bank of mechanically vibratory elements, a bank of piezo-electric elements, one mechanically connected to each of the vibratory elements, means for passing a light beam to the vibratory elements, means for focusing sound waves from an object upon the piezo-electric elements to cause the resulting vibrations of the respective vibratory elements to effect modulation of the light beam in accordance with the sound energy of the sound waves focused upon the respective piezo-electric elements, and means controlled in accordance with the modulation of the light beam for producing a likeness of the object.

20. An electric system having, in combination, a plurality of cells, a plurality of piezo-electric elements, one connected to each of the cells, means for impressing a voltage upon the elements, means for impressing sound waves upon the elements to convert the impressed sound waves into sound disturbances in the cells, and means controlled by the sound disturbances in the cells for producing a likeness corresponding to the sound energy impressed upon the elements.

21. An electric system having, in combination,

a plurality of vibratory sound-receiving elements, a electric oscillatory means for vibrating the elements, means for impressing sound waves upon the elements to modify the vibration thereof, and means controlled in accordance with the modified vibrations of the elements for producing a likeness corresponding to the sound energy impressed upon the elements.

22. A method of the character described that comprises passing successive transverse portions of a light beam through corresponding successive portions of a refractive medium, focusing sound waves from an object upon the medium, causing the focused sound waves to vibrate the successive portions of the medium so that the vibrations of the successive portions of the medium alter their refractive index, and thereby effect modulation of the successive transverse portions of the light beam in accordance with the sound waves focused from the object, and producing a likeness of the object in accordance with the modulation of the successive transverse portions of the light beam.

23. In a system having a refractive medium that is transparent to light along a predetermined direction and that when ultrasonically vibrated to produce standing waves therein has its refractive index modified, a method of the character described that comprises passing through the medium along the predetermined direction a bundle of light waves, polarizing the light prior to its passage through the medium, analyzing the light after its passage through the medium to a degree such that the light is extinguished in the absence of ultrasonic vibration, and impinging ultrasound waves upon the medium.

24. An electric system having, in combination, a bank of sound-receiving elements for receiving a distribution of sound waves from an object, a bank of refractive elements corresponding to the bank of sound-receiving elements and mechanically vibratory in response to the sound waves received by the sound-receiving elements, means for passing a light beam through the refractive elements, means for focusing sound wavesfrom an object upon the bank of sound-receiving elements to cause the resulting mechanical vibrations of the refractive elements to alter the refractive index of the refractive elements thereby to effect modulation of the light beam in accordance with the focused sound waves, and means responsive to the light modulation for producing a likeness of the object.

25. An electric system having, in combination, light transparent means having a refractive index, vibratory means responsive to sound waves and disposed in mechanical contact with the light transparent means, means for passing successive transverse portions of a polarized light beam through corresponding successive portions of the light transparent means, means for impinging sound waves from an object upon the vibratory means to vibrate the vibratory means and to index of the successive portions of the light transparent means, and analyzing means for detecting the effect upon the successive transverse portionsof the light beam of the mechanical vibration of the corresponding successive portions of the light transparent means, thereby to produce a likeness of the object.

26. In an electric system having a light-transparent medium mechanically vibratory in response to sound waves, a method of the character, described that comprises passing successive transverse portions of a polarized light beam to corresponding successive portions of the medium, focusing sound waves from corresponding successive portions of an object upon the successive portions of the medium to cause 'the resulting mechanical vibrations toeffect modulation of the corresponding successive transverse portions of the polarized light beam in accordance with the sound waves focused from the corresponding successive portions of the object and causing the modulation of the successive transverse portions of the polarized light beam to produce a likeness of the object.

27. An electric system having, in combination, piezoelectric means, means for converging sound energy emanating from an object upon the piezoelectric means to set the piezo-electric means into mechanical vibration, piezo-electric-oscillator means comprising the piezo-e1ectric means for enhancing the mechanical vibrations set up in the piezo-electric means, and means responsive to the enhanced mechanical vibrations set up in the piezo-electric means for producing a likeness of the object.

28. An electric system having, in combination, piezoelectric means, means for converging sound energy emanating from an object upon the piezoelectric means to set the piezo-electric means into mechanical vibration, piezo-electric-oscillator means comprising the piezo-electric means for enhancing the mechanical vibrations set up in the piezo-electric means, and light-modulation means responsive to the enhanced mechanical vibrations set up in the piezo-electric means for producing a likeness of the object.

29. An electric system having, in combination, mechanically vibratory means adapted to be set into mechanical vibration in response to sound energy impinging thereon, means ior-converging sound energy emanating from an object upon the mechanically vibratory means to set the mechanically vibratory means into mechanical vibration, means for converting the energy oi. the mechanical vibration of the mechanically vibratory means into electric energy, means responsive to the electric energy for enhancing the mechanical vibrations set up in the mechanically vibratory means to enhance furtherthe electric energy into which the energy of the mechanical vibration 01' the mechanically vibratory means is converted, and light-modulation means controlled in accordance with the enhanced mechanical ponent parts of the object the sound emanating from which impinges upon them, electric-circuit means, means for connecting the piezo-electric elements to the electric-circuit means to provide piezo-electric-oscillator means for enhancing the mechanical vibrations set up in the piezo-electric elements, and means responsive to the enhanced mechanical vibrations set up in the piezo-electric elements to produce portions of a likeness of the object corresponding to the sound energy impinging upon the respective piezo-electric elements.

31. An electric system having, in' combination, a plurality of piezo-electric sound-receiving elements, means for converging sound emanating from an object upon the piezo-electric elements to set the piezo-electric elements into mechanical vibration, the piezo-electric elements respectively corresponding to respective component parts of the object the sound emanating from which impinges upon them, electric-circuit means, means for connecting the piezo-electric elements to the electric-circuit means to provide piezo-electricoscillator means for enhancing the mechanical vibrations set up in the piezo-electric elements, and light-modulation means responsive to the enhanced mechanical vibrations set up in the piezo-electric elements to produce portions of a likeness of the object corresponding to the sound energy impingin upon the respective piezoelectric elements.

32. 'An electric system having, in combination, piezo-electric means, means for converging sound energy eman'ating from an object upon the piezoelectric means to set the piezo-electric means into mechanical vibration, means for enhancing the mechanical vibrations set up in the piezo-electric means, and means controlled in accordance with the enhanced mechanical vibrations of the piezoelectric means for producing a likeness of the object.

33. An electric system having, in combination, a plurality of piezo-electric sound-receiving elements, means for converging sound energy emanating from an object upon the piezo-electric elements to set the piezo-electric elements into mechanical vibration, means for enhancing the mechanical vibrations set up in the piezo-electric elements, and means controlled in accordance with the enhanced mechanical vibrations of the piezo-electric elements for producing a likeness of the object.

ROBERT HARVEY RINES.

REFERENCES CITED The following references are of record in the file of this patent:

.UNITED STATES PATENTS Number Name Date 1,565,566 Hartley Dec. 15, 1925 1,760,383 Thomas May 27, 1930 1,996,449 Zworykin Apr. 2, 1935 2,031,884 Gray Feb. 25, 1936 2,212,845 Nicolson Aug. 27, 1940 2,216,949 Kellogg Oct. 9, 1940 2,411,146 Clement Nov. 19, 1946 2,424,976 Golay Aug. 5, 1947 2,453,502 Dimmick Nov. 9, 1948 FOREIGN PATENTS Number Country Date 347,022 Great Britain Apr. 23, 1931 541,959 Great Britain Dec. 19, 1941

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