US4678905A — Optical sensors for detecting physical parameters…

Claim 1

Independent Claim 100 words

A transducer apparatus for detecting a physical parameter comprising: a piezoelectric member which transmits light; means for supplying light to the member, so that the light supplied is transmitted through the member; means for vibrating the member in a direction transverse to the light transmitted in the member so that the vibrations of the member is modulated by the physical parameter, and so that said modulations of the vibrations also modulate the intensity of the light transmitted by the member; and means for detecting modulations of the intensity of the light transmitted by the member to detect said physical parameter.

Claim 2

Dependent Claim 100 words

A transducer apparatus for detecting a physical parameter comprising: a piezoelectric member which transmits light; means for supplying light to the member, so that the light supplied is transmitted through the member; means for vibrating the member in a direction transverse to the light transmitted in the member so that the vibrations of the member is modulated by the physical parameter, and so that said modulations of the vibrations also modulate the intensity of the light transmitted by the member; and means for detecting modulations of the intensity of the light transmitted by the member to detect said physical parameter.

Claim 3

Dependent Claim 12 words

The apparatus of claim 1, wherein said member comprises a quartz crystal.

Claim 4

Dependent Claim 18 words

The apparatus of claim 1, wherein said vibrating means includes means for applying a voltage to the member.

Claim 5

Dependent Claim 40 words

The apparatus of claim 1, wherein said vibrating means includes optical and electrical feedback means for applying a voltage to the member, and wherein said voltage varies with the modulations of the intensity of the light transmitted by the member.

Claim 6

Dependent Claim 14 words

The apparatus of claim 1, wherein said member is a tuning fork type transducer.

Claim 7

Dependent Claim 33 words

The apparatus of claim 5, wherein the light is supplied to the member at the base of the fork so that the light is transmitted towards and through the tines of the member.

Claim 8

Dependent Claim 65 words

The apparatus of claim 6, wherein said detecting means includes an optical fiber for receiving light transmitted through the member and emitting from the ends of the tines of the member, and wherein the physical parameter modulates the amount of light emitting from the ends of the tines and received by the optical fiber to modulate the intensity of light received by the optical fiber.

Claim 9

Dependent Claim 47 words

The apparatus of claim 7, wherein the member further comprises a frame integral with the tuning fork, and wherein the optical fiber and the mirror are attached to the frame so that alignment of the fiber and mirror with the tines of the tuning forks is facilitated.

Claim 10

Dependent Claim 74 words

The apparatus of claim 6, wherein one of the tines has a U-shaped portion at its end so that its end bends over to face the end of the other tine, said apparatus further comprising a mirror substantially at the base of said U-shaped portion to reflect light travelling down the tine with the U-shaped portion, so that the physical parameter modulates the light transmitted between the ends of the tines of the member.

Claim 11

Dependent Claim 62 words

The apparatus of claim 8, wherein the indices of refraction of the member and its environment are such that the member acts as light guide to transmit light and wherein the ends of the tines are saw-tooth in shape for focusing the light towards reduced areas for transmission between the tines, thereby increasing the magnitude of light modulation by the physical parameter.

Claim 12

Dependent Claim 81 words

The apparatus of claim 5, said apparatus further comprising a mirror connected substantially at the base of the fork and an optical fiber facing the ends of the two tines, wherein the light is supplied to the ends of the tines through the optical fiber so that the light is reflected by the mirror back towards the ends of the tines to be received by the optical fiber, and wherein the physical parameter modulates the light received by the optical fiber.

Claim 13

Dependent Claim 47 words

The apparatus of claim 11, wherein the member further comprises a frame integral with the tuning fork, and wherein the optical fiber and the mirror are attached to the frame so that alignment of the fiber and mirror with the tines of the tuning forks is facilitated.

Claim 14

Dependent Claim 84 words

The apparatus of claim 5, said apparatus further comprising an optical fiber with one end connected to the base of the fork and a mirror placed facing the ends of the two tines, wherein the light is supplied to one of the tines through the optical fiber so that the light is reflected by the mirror down the other tine to be received by the optical fiber, and wherein the physical parameter modulates the light received by the optical fiber from the other tine.

Claim 15

Dependent Claim 47 words

The apparatus of claim 13, wherein the member further comprises a frame integral with the tuning fork, and wherein the optical fiber and the mirror are attached to the frame so that alignment of the fiber and mirror with the tines of the tuning forks is facilitated.

Claim 16

Dependent Claim 94 words

The apparatus of claim 5, wherein the indices of refraction of the member and its environment are such that the member acts as a light guide, wherein the two tines bend with their ends facing each other, and wherein the light is supplied to the base of the fork towards one of the tines, guided by said tine towards and passes out of its end, transmitted towards and received by the end of the other tine, and guided by the other tine towards the base of the fork for detection by the detection means.

Claim 17

Dependent Claim 33 words

The apparatus of claim 15, wherein the two lines taper towards their ends for focusing the light transmitted between their ends, thereby increasing the magnitude of the modulation caused by the physical parameter.

Claim 18

Dependent Claim 58 words

The apparatus of claim 15, wherein the two tines taper towards their ends for focusing the light transmitted between their ends, wherein their ends are in the shape of two knife edges facing each other, and wherein the vibrations are transverse to the two knife edges, thereby increasing the magnitude of the modulation caused by the physical parameter.

Claim 19

Dependent Claim 30 words

The apparatus of claim 5, wherein the vibrating means vibrates the tines of the tuning fork in directions substantially in the plane containing the two tines in a flexural mode.

Claim 20

Dependent Claim 27 words

The apparatus of claim 5, wherein the vibrating means vibrates the tines of the tuning fork in directions substantially normal to the plane containing the two tines.

Claim 21

Dependent Claim 27 words

The apparatus of claim 5, wherein the vibrating means vibrates the tines of the tuning fork by rotating each of the two tines in a torsional mode.

Claim 22

Independent Claim 69 words

The apparatus of 1, wherein the member comprises a first and a second tuning fork with their tines facing each other, said apparatus further comprising gratings on the tines of the two forks in matching positions, wherein the gratings on the first tuning fork are light absorbent, and wherein the light supplied passes through the first tuning fork between the gratings thereon to impinge on the second tuning fork.

Claim 23

Independent Claim 69 words

The apparatus of 1, wherein the member comprises a first and a second tuning fork with their tines facing each other, said apparatus further comprising gratings on the tines of the two forks in matching positions, wherein the gratings on the first tuning fork are light absorbent, and wherein the light supplied passes through the first tuning fork between the gratings thereon to impinge on the second tuning fork.

Claim 24

Dependent Claim 30 words

The apparatus of claim 21, wherein the gratings on the second tuning fork is light absorbent so that the physical parameter modulates the light transmitted by the second tuning fork.

Claim 25

Dependent Claim 33 words

The apparatus of claim 21, wherein the gratings on the second tuning fork is light reflective so that the physical parameter modulates the light reflected by the gratings on the second tuning fork.

Claim 26

Dependent Claim 45 words

The apparatus of claim 21, wherein the gratings are located near the ends of the tines of the two forks, so that the light transmitted by the member for detecting the physical parameter are modulated by vibrations of the tuning forks in their fundamental frequencies.

Claim 27

Dependent Claim 47 words

The apparatus of claim 21, wherein the gratings are located at or near the center of the tines of the forks, so that the light transmitted by the member for detecting the physical parameter are modulated by vibrations of the tuning forks in their first harmonic frequencies.

Claim 28

Dependent Claim 16 words

The apparatus of claim 21 wherein the first and second tuning forks are closed-end turning forks.

Claim 29

Dependent Claim 47 words

The apparatus of claim 26, wherein the gratings are located at or near the centers of the tines of the two forks, so that the light transmitted by the member for detecting the physical parameter are modulated by vibrations of the tuning forks in their fundamental frequencies.

Claim 30

Dependent Claim 45 words

The apparatus of claim 26, wherein the gratings are located away from the centers of the tines of the forks, so that the light transmitted by the member for detecting the physical parameter is modulated by vibrations of the tuning forks in their harmonic frequencies.

Claim 31

Dependent Claim 194 words

The apparatus of claim 1, wherein the member comprises a portion in the form of a closed-end tuning fork and a second portion in the form of two arms with their bases integral with and originating from the two ends of the elongated space between the two tines extending towards each other with space left therebetween, the two bases or ends of the closed-end tuning fork defining a first and a second side of the member, said apparatus further comprising a mirror connected to the first side of the member, said two tines having fingers extending towards the space between the ends of the two arms, and wherein the light is supplied to the second side of the member so that light is transmitted down one of the two arms, through the space between the two arms and into the other arm, is reflected by the mirror at the first side of the member and transmitted back through the two arms towards the second side of the member so that when the two tines vibrate, the two fingers will modulate the amount of light transmitted between the two arms to detect the physical parameter.

Claim 32

Dependent Claim 54 words

The apparatus of claim 29, wherein the indices of refraction of the member and its environment are such that the two arms act as light guides, and wherein the two arms taper towards their ends, thereby focusing the light transmitted therebetween to increase the magnitude of the light modulation caused by the physical parameter.

Claim 33

Dependent Claim 26 words

The apparatus of claim 7, wherein the indices of refraction of the member and its environment are such that the member acts as a light guide.

Claim 34

Dependent Claim 47 words

The apparatus of claim 7, said appratus further comprising gratings on the ends of the two tines or on the ends of at least one tine and the optical fiber to increase the magnitude of the modulations of the intensity of light detected by the detecting means.

Claim 35

Independent Claim 13 words

The apparatus of claims 1, 5, 7, wherein said physical parameter is pressure.

Claim 36

Dependent Claim 83 words

The apparatus of claim 33, said apparatus being suitable for measuring pressure at a location, said apparatus further comprising: a housing for said member, said housing having an opening at one end adapted for reaching said location; a diaphragm sealing said opening, said diaphragm being flexible so that when said end of the housing is placed at said location, the pressure at said location will influence the density of a gas inside the housing which in turn influences the vibration of the member.

Claim 37

Independent Claim 13 words

The apparatus of claims 1, 5, 7, wherein said physical parameter is temperature.

Claim 38

Independent Claim 15 words

The apparatus of claims 1, 5, 7, wherein said physical parameter is a chemical substance.

Claim 39

Dependent Claim 23 words

The apparatus of claim 36, further comprising a chemically active compound on said member, said compound having an affinity for said chemical substance.

Claim 40

Independent Claim 13 words

The apparatus of claims 1, 5, 7, wherein said physical parameter comprises particles.

Claim 41

Dependent Claim 15 words

The apparatus of claim 38, further comprising a compound having an affinity for said particles.

Claim 42

Independent Claim 14 words

The apparatus of claims 26 or 29, wherein said physical parameter is a force.

Claim 43

Dependent Claim 21 words

The apparatus of claim 40, wherein the force is applied to one end of the one or more closed-end tuning forks.

Claim 44

Independent Claim 67 words

The apparatus of claims 26 or 29, wherein said physical parmeter is a displacement, said apparatus further comprising a spring connected to one end of the one or more closed-end tuning forks, wherein said displacement is applied to said one end of the tuning forks through the spring, so that the displacement causes the spring to apply a force to said one end of the tuning forks.

Claim 45

Independent Claim 58 words

The apparatus of claims 26 or 29, wherein said physical parameter is acceleration, said apparatus further comprising a mass in contact with one end of the one or more closed-end tuning forks, wherein said acceleration is applied to said mass, so that the acceleration of the mass applies a force to said one end of the tuning forks.

Claim 46

Independent Claim 63 words

The apparatus of claims 1, 5, 7, wherein said physical parameter is pressure, and wherein said member is surrounded by a gas and is held at a substantially constant temperature so that the pressure of the gas is indicated by the modulations of the intensity of the light transmitted by said member as influenced by the condensation of the gas on the member.

Claim 47

Dependent Claim 95 words

A transducer apparatus for detecting a physical parameter comprising: a piezoelectric member which transmits light; means for supplying light to the member, so that the light supplied is transmitted through the member; electrical means for moving the member in a direction transverse to the light transmitted in the member so that the movement of the member is modulated by the physical parameter, and so that said modulations of the vibrations also modulate the light transmitted by the member; and means for detecting modulations of the light transmitted by the member to detect said physical parameter.

Claim 48

Dependent Claim 95 words

A transducer apparatus for detecting a physical parameter comprising: a piezoelectric member which transmits light; means for supplying light to the member, so that the light supplied is transmitted through the member; electrical means for moving the member in a direction transverse to the light transmitted in the member so that the movement of the member is modulated by the physical parameter, and so that said modulations of the vibrations also modulate the light transmitted by the member; and means for detecting modulations of the light transmitted by the member to detect said physical parameter.

Claim 49

Dependent Claim 42 words

The apparatus of claim 45, wherein said physical parameter is a light signal, and wherein said electrical means is responsive to said signal for converting said light signal to an electrical signal which is applied to said member for moving said member.

Claim 50

Dependent Claim 44 words

The apparatus of claim 45, wherein said physical parameter is a group of electrons, and wherein said electrical means is responsive to said group of electrons thereby converting said group to an electrical signal which is applied to said member for moving said member.

Claim 51

Dependent Claim 42 words

The apparatus of claim 45, wherein said physical parameter is an X-ray signal, and wherein said electrical means is responsive to said signal for converting said X-ray signal to an electrical signal which is applied to said member for moving said member.

Claim 52

Dependent Claim 41 words

The apparatus of claim 45, wherein said physical parameter is a radiation signal, and wherein said electrical means is responsive to said signal for converting said signal to an electrical signal which is applied to said member for moving said member.

Claim 53

Dependent Claim 41 words

The apparatus of claim 45, wherein said physical parameter is a force signal, wherein said electrical means is responsive to said signal for converting said force signal to an electrical signal which is applied to said member for moving said member.

Claim 54

Dependent Claim 12 words

The apparatus of claim 50, said electrical means is a piezoelectric element.

Claim 55

Dependent Claim 43 words

The apparatus of claim 45, wherein said physical parameter is a varying magnetic field signal, and wherein said electrical means is responsive to said signal for converting said signal to an electrical signal which is applied to said member for moving said member.

Claim 56

Dependent Claim 12 words

The apparatus of claim 52, wherein said electrical means is an inductor.

Claim 57

Dependent Claim 15 words

The apparatus of claim 1 further comprising means for controlling the temperature of the member.

Claim 58

Dependent Claim 24 words

The apparatus of claim 54, wherein said temperature controlling means comprises a narrow band light absorbent coating on the member and a light source.

Claim 59

Independent Claim 81 words

A method for detecting a physical parameter comprising: supplying light to a light transmitting, light reflecting or light blocking piezoelectric member; moving the member so that the movement of the member is modulated by the physical parameter, and so that said modulations of the movement also modulate the intensity of the light transmitted, reflected or blocked by the member; and detecting the modulations of the intensity of the light transmitted, reflected or blocked by the member to detect said physical parameter.

Claim 60

Independent Claim 81 words

A method for detecting a physical parameter comprising: supplying light to a light transmitting, light reflecting or light blocking piezoelectric member; moving the member so that the movement of the member is modulated by the physical parameter, and so that said modulations of the movement also modulate the intensity of the light transmitted, reflected or blocked by the member; and detecting the modulations of the intensity of the light transmitted, reflected or blocked by the member to detect said physical parameter.

Claim 61

Independent Claim 81 words

A method for detecting a physical parameter comprising: supplying light to a light transmitting, light reflecting or light blocking piezoelectric member; vibrating the member so that the vibration of the member is modulated by the physical parameter, and so that said modulations of the vibration also modulate the intensity of the light transmitted, reflected or blocked by the member; and detecting the modulations of the intensity of the light transmitted, reflected or blocked by the member to detect said physical parameter.

Claim 62

Independent Claim 81 words

A method for detecting a physical parameter comprising: supplying light to a light transmitting, light reflecting or light blocking piezoelectric member; vibrating the member so that the vibration of the member is modulated by the physical parameter, and so that said modulations of the vibration also modulate the intensity of the light transmitted, reflected or blocked by the member; and detecting the modulations of the intensity of the light transmitted, reflected or blocked by the member to detect said physical parameter.

Claim 63

Dependent Claim 47 words

The method of claim 57, wherein said vibrating step includes: supplying light to a cell in the vicinity of the member, said cell capable of transforming the light supplied thereto into electrical current; supplying the electrical current from the cell to the member to vibrate the member.

Claim 64

Independent Claim 87 words

An apparatus for detecting a physical parameter comprising: a light transmitting, reflecting or blocking piezoelectric member; means for supplying light to the member; means for vibrating the member so that the vibration of the member is modulated by the physical parameter, and so that said modulations of the vibration also modulate the intensity of the light transmitted, reflected or blocked by the member; and means for detecting the modulations of the intensity of the light transmitted, reflected or blocked by the member to detect said physical parameter.

Claim 65

Independent Claim 87 words

An apparatus for detecting a physical parameter comprising: a light transmitting, reflecting or blocking piezoelectric member; means for supplying light to the member; means for vibrating the member so that the vibration of the member is modulated by the physical parameter, and so that said modulations of the vibration also modulate the intensity of the light transmitted, reflected or blocked by the member; and means for detecting the modulations of the intensity of the light transmitted, reflected or blocked by the member to detect said physical parameter.

Claim 66

Independent Claim 61 words

The apparatus of claims 1 or 59, wherein said vibrating means includes: a cell in the vicinity of the member, said cell capable of transforming light into electrical current, wherein said means for supplying light to the member also supplies light to the cell; and means for supplying the electrical current from the cell to the member to vibrate the member.

Claim 67

Independent Claim 55 words

The apparatus of claims 1 or 59, wherein said vibrating means includes: a cell in the vicinity of the member, said cell capable of transforming light into electrical current; a second means for supplying light to the cell; and means for supplying the electrical current from the cell to the member to vibrate the member.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-07-06	1991-01-05	1991-07-07	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-07-06	1995-01-05	1995-07-07	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-07-06	1999-01-05	1999-07-07	$7700.00	Window Closed / Lapsed

Optical sensors for detecting physical parameters utilizing vibrating piezoelectric elements

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