U.S. patent number 3,691,316 [Application Number 05/034,506] was granted by the patent office on 1972-09-12 for semiconductor stress transducer.
This patent grant is currently assigned to Matsushita Electric Industrial Co.. Invention is credited to Fujio Oda, Shuichi Obata.
United States Patent |
3,691,316 |
|
September 12, 1972 |
SEMICONDUCTOR STRESS TRANSDUCER
Abstract
A semiconductor stress transducing apparatus in which a
semiconductor layer having a large piezo-resistance effect is
deposited by vacuum evaporation on a highly flexible thin-film
substrate of an insulating material and a bending stress is
imparted to the deposited semiconductor layer through a flowable
viscous material, whereby a change in the internal resistance of
the semiconductor layer is detected.
Inventors: |
Fujio Oda (Ashiya, JP),
Shuichi Obata (Kyoto, JP) |
Assignee: |
Matsushita Electric Industrial
Co. (Ltd., Osaka)
|
Family
ID: |
27460323 |
Appl.
No.: |
05/034,506 |
Filed: |
May 4, 1970 |
Foreign Application Priority Data
|
|
|
|
|
May 9, 1969 [JP] |
|
|
44/36830 |
May 9, 1969 [JP] |
|
|
44/36831 |
May 9, 1969 [JP] |
|
|
44/36833 |
May 9, 1969 [JP] |
|
|
44/36832 |
|
Current U.S.
Class: |
369/137; 338/2;
369/152; 369/145; 381/175 |
Current CPC
Class: |
H04R
21/02 (20130101); H04R 21/04 (20130101) |
Current International
Class: |
H04R
21/04 (20060101); H04R 21/02 (20060101); H04R
21/00 (20060101); H04r 001/16 (); H04r 009/12 ();
H04r 011/08 () |
Field of
Search: |
;179/100.41K,100.41V,110B,110D,100.41T ;338/2,5 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Robert L. Griffin
Assistant Examiner: Richard K. Eckert, Jr.
Attorney, Agent or Firm: Stevens, Davis, Miller &
Mosher
Claims
1. A pick-up cartridge, comprising, in combination: a frame member
having a cavity formed therein; a flowable viscous material
contained in said cavity; a cantilever having a needle point at one
end thereof; an insulating film substrate fixed at the other end of
said cantilever and having a plurality of arms extending from the
portion of said substrate fixed to said cantilever; band-shaped
semiconductor elements formed on said plurality of arms by vacuum
evaporation; and electrodes formed at opposite ends of said
semiconductor elements; wherein said plurality of arms are disposed
in said cavity and supported by said flowable viscous material,
such that a vibrational stress transmitted from said needle point
is imparted through said cantilever to said semiconductor elements
as a bending stress to correspondingly change the
2. The pick-up cartridge defined in claim 1, wherein said plurality
of arms comprises two arms extending radially of the longitudinal
axis of said cantilever and substantially perpendicular to each
other in a common plane
3. The pick-up cartridge defined in claim 1, wherein said plurality
of arms comprises four arms extending substantially perpendicular
to each other in a cross shape in a common plane perpendicular to
the longitudinal axis of
4. The pick-up cartridge defined in claim 1, wherein said plurality
of arms extend from said portion fixed to said cantilever parallel
to the longitudinal axis of said cantilever.
Description
The present invention relates to a semiconductor stress transducer
which converts mechanical stress into electricity using a
semiconductor film element.
Various type of sound converting element, utilizing the
piezo-resistance effects of single crystals of silicon and
germanium, have been proposed heretofore. However, in order to
obtain a sufficient effect of conversion and output voltage, any
one of these prior art elements must be fabricated into the shape
of a rod or thin plate having an extremely small cross-sectional
area, such 0.1 mm.sup.2 or smaller, and further it must be bonded
to a mechanical vibration system so as to receive a uniaxial
stress. Such a prior art element using a single crystal is so small
in mechanical compliance that difficulties have frequently been
encountered in the mechanical construction to obtain a converting
apparatus of satisfactory sound characteristic. In addition, the
fabrication of the semiconductor element, involving an extremely
delicate work, has called for a high degree of skill and yet
further, because of the insufficient mechanical strength, the
element thus obtained has frequently become unserviceable during
the process of assembly.
It is, therefore, the object of the present invention to provide a
semiconductor stress transducer which utilizes the piezo-resistance
effect of a semiconductor layer deposited on a flexible thin-film
of an insulating material, and which, therefore, can be produced by
a simple process.
According to the present invention, a bending stress is imposed on
the semiconductor piezo-resistance element uniformly continuously
through a flowable viscous material and local concentration of an
excessively large stress can be avoided. Therefore, a breakage of
the element can be avoided. Further, any desired damping effect can
be obtained by suitable selecting the configuration of the
insulating film base, the configuration of a supporting structure
and the type of the flowable viscous material. In other words, the
damping effect, compliance and output voltage can be designed very
easily. Another advantage of the present invention is that, since
the semiconductor piezo-resistance element is a pure resistor, it
will not be subjected to a detrimental induction and furthermore,
since it is formed by vacuum evaporation, it can be provided in an
extremely small size and can be used with stability, even on
excitation of high frequencies. A further excellent advantage of
the present invention is that the element can be produced in a
large quantity of a single process, so that the elements of uniform
quality can be obtained at low costs, and moreover the construction
thereof is simple.
Further features of the present invention will become apparent from
the following description of the embodiments of the invention when
taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a cross-sectional view exemplifying the semiconductor-
deposited film element to be used in the semiconductor stress
transducer of the present invention;
FIG. 2 is a diagram for explaining the basic construction and
operation of the apparatus according to the invention;
FIGS. 3a-3c are a set of views showing different forms of the
semiconductor-deposited film element;
FIG. 4 is a cross-sectional view showing an embodiment of the
pickup cartridge according to the invention;
FIG. 5 is a perspective view of the pickup cartridge showing the
construction inside thereof;
FIG. 6 is an exploded perspective view of the pickup cartridge;
FIG. 7 is a front view of the semiconductor-deposited film
element;
FIGS. 8 and 9 are front views of the other forms of the
semiconductor-deposited film element respectively;
FIG. 10 is a cross-sectional view of another embodiment of the
pickup cartridge according to the invention;
FIG. 11 is a perspective view of the pickup cartridge of FIG. 10,
with the front cap thereof removed;
FIG. 12 is an exploded perspective view of the pickup cartridge of
FIG. 10;
FIGS. 13 and 14 are front views of the other forms of the
semiconductor deposited film element respectively;
FIG. 15 is a cross-section view of still another embodiment of the
pickup cartridge according to the invention;
FIG. 16 is a perspective view of the pickup cartridge of FIG.
15;
FIG. 17 is an exploded perspective view of the pickup cartridge of
FIG. 15;
FIG. 18 is a front view of the semiconductor-deposited film element
of the embodiment of FIGS. 15-17; and
FIGS. 19 and 20 are cross-sectional views of a microphone in which
the present invention is embodied.
Referring first to FIG. 1, there is shown an embodiment of the
semiconductor-deposited film element used in the apparatus of this
invention. In the Figure, reference numeral 1 designates a
substrate which consists of a heat-resistant, insulating and highly
flexible film made of such material as polyimide, polyamide or
mica, and having a thickness of about several tens microns.
Reference numerals 2,2' designate electrodes which are provided on
the base plate 1 by depositing a metal, such as nickel, chromium or
gold, by vacuum evaporation. Reference numeral 3 designates a
semiconductor piezo-resistance element which is formed by
depositing a semiconductor material of large piezo-resistance
effect, e.g., silicon, germanium, indium, antimony or the like with
a suitable quantity of a selected impurity blended therein, by
vacuum evaporation in the shape of a band bridging the electrodes
2, 2', using a suitable mask. Therefore, when the semiconductor
piezo-resistance element 3 undergoes a tension change in the
direction to connect the electrodes 2, 2' or a deformation under a
bending stress exerted on the entire body thereof, a change occurs
in the resistance across the electrode terminals due to a
mechanical deflection. FIG. 2 is a view to explain the principle of
a stress converting apparatus incorporating the
semiconductor-deposited film element constructed as described
above. Reference numeral 4 designates an insulating holder
supporting one end, i.e. the electrode 2, of the
semiconductor-deposited film element and 5 designates another
holder supporting the other end of the same. The holder 5 is
provided with a cavity 6 in which are received the other electrode
2' and the semiconductor piezo-resistance element 3 of the
semiconductor-deposited film element. The cavity 6 is filled with a
viscous material 7 consisting of a silicon-base grease or the like,
and the other end portion of the semiconductor-deposited film
element is supported by the holder 5 through said flowable viscous
material 7.
In the construction described above, when the holder 4 or 5 is
displaced in the direction of the arrow 8, a bending stress occurs
in the semiconductor piezo-resistance element 3 due to the braking
effect of the member 7. As a result, the semiconductor
piezo-resistance element 3 is pulled or compressed and the internal
resistance thereof varies according to the displacement of the
holder 4. It will, therefore, be understood that, when a
direct-current source 9, such as a battery, and a load resistance
10 are connected in series with the semiconductor piezo-resistance
element 3 to form a closed circuit, the resistance change of said
semiconductor piezo-resistance element 3 is detected as a voltage
change at the terminal end of the load resistance 10 and the
resultant alternating-current component is taken out through a
capacitor 11. The resistance of the semiconductor piezo-resistance
element 3 can be changed similarly by displacing the holder 5 in
the direction of the arrow 12, while holding the holder 4
stationary.
The construction of the semiconductor-deposited film element 3 can
vary widely as exemplified in FIG. 3. For instance, the
semiconductor- deposited film element 3 may be constructed as shown
in FIG. 3 a wherein two semiconductor piezo-resistance elements 3,
3' are formed on an insulating film base plate 1, with one ends
thereof connected to electrodes 2, 2" respectively and with the
other ends connected to a common electrode 2', so as to be used in
series, or as shown in FIG. 3b wherein the insulating film
substrate 1 is provided with recesses 13, 13' on both side edges
thereof so as to make large the resistance change of the
semiconductor piezo-resistance elements 3, 3' caused by a bending
stress imposed on said insulating film substrate 1, or further as
shown in FIG. 3c wherein an electrode 2", connected to an electrode
2' is provided in side-by-side relation with an electrode 2 so as
to facilitate the connection of the electrodes with the external
elements. Besides those described above, many other constructions
can of course be employed.
Now, the practical construction of the pick-up cartridge according
to the present invention will be described hereunder:
With reference to FIGS. 4, 5 and 6, reference numeral 13 designates
a needle point which traces the sound track of a phonograph record
to detect the vibration; 14 a cantilever to transmit the vibration
of the needle point 13 to a mechano-electrical transducing unit,
said cantilever being made of a light alloy material; and 15 an
ultrafine wire constituting a fulcrum of vibration when said needle
point 13 and said cantilever 14 vibrate according to the sound
track. The ultrafine wire 15 is securely supported at one end by a
spacer 16 which is fitted into the inner end of the cantilever
14.
Reference numeral 17 designates a supporting member to secure the
ultrafine wire 15 to the main body, i.e. the mounting block, of the
cartridge. The supporting member 17 is fixed on the ultrafine wire
15, with a slight gap of 1 mm or smaller between it and the inner
end of the cantilever 14, so as to provide for free vibration of
the needle point 13 and the cantilever 14 about the ultrafine wire
15.
Reference numeral 18 designates a supporting member which clamps
between it and a damping support material 20, consisting of an
elastic material or the like, an insulating film substrate 19
having a semiconductor film deposited thereon.
Reference numeral 21 designates a cylindrical mounting block made
of an insulating material and having a recess 22 formed in one end
face thereof. The bottom of the recess 22 is formed with a recess
23 at a portion thereof for receiving one end of the damping
support material 20. An elongate hole 25 is bored from the center
of the recess 23, communicating said recess 23 with a recess 24
provided in the other end face of the mounting block 21.
On the other hand, terminal rods 26 are embeded in the mounting
block 21, with the opposite ends thereof projecting into the recess
22 in one end face and the recess 24 in the other end face of said
mounting block respectively, and the ends projecting into the
recess 24 are connected with lead terminals 28 respectively which
are provided on a terminal plate 27 securely fitted in said recess
24.
In assembling the pickup cartridge, the supporting member 18 is
fitted on the terminal end of the cantilever 14 at first and then
the insulating film base plate 19 and the damping support material
20 are fitted in such a manner as to clamp the insulating film
substrate 19 between said supporting member 18 and said damping
support 20. Thereafter, the supporting member 17 is inserted into
the hole 25 in the mounting block 21, while holding the damping
support 20 in pressure contact with the bottom of the recess 23,
and is secured to said mounting block 21 by means of an adhesive or
the like. Here, the insulating film substrate 19 corresponds to the
substrate 1 shown in FIGS. 1 and 2, and has integral arms 29, 30
lying in the same plane in substantially perpendicular relation to
each other to form a V-shape as shown in FIG. 6. The insulating
film substrate 19 is provided with a hole 31 at the flexed portion
thereof, through which the supporting member 17 is inserted, and is
clamped between the supporting member 18 and the damping support
20.
As shown in FIG. 7, on each of the arms 29, 30 are formed by vacuum
evaporation semiconductor piezo-resistance elements 36, 36' or 37,
37' of the same conditions as that shown in FIG. 1, with one ends
thereof connected with electrodes 34, 34' or 35, 35' and the other
ends connected with a common electrode 32 or 33. The arms 29, 30,
provided with the semiconductor piezo-resistance elements 36, 36'
and 37, 37' respectively, are positioned within the recess 22 of
the mounting block 21 with an air space between them and the bottom
wall of said recess, sand said recess 22 is filled with a flowable
viscous material 38. Thus, it will be seen that the arms 29, 30 are
held by the mounting block 21 through the flowable viscous material
38. The electrodes 34, 34' and 35, 35' are connected with the
terminal rods 26 respectively and the two semiconductor
piezo-resistance element 36, 36' or 37, 37' are connected in series
with each other. Reference numeral 39 designates a front cap of the
pickup cartridge.
The operation of the pickup cartridge of the invention having the
construction as described above will be briefly explained hereunder
with reference to FIG. 5.
When a vibration is imparted to the needle point 13 as indicated by
the arrows 40, said needle point 13 and the cantilever 14 are moved
in the same directions. Therefore, the semiconductor
piezo-resistance elements 36, 36', parallel to the arrows 40
undergo a vibration as indicated by the arrows 43, so that a
bending stress is created in said semiconductor piezo-resistance
element 36, 36' by the flowable viscous material 38. As a result,
the internal resistance of the semiconductor piezo-resistance
elements 36, 36' across the electrodes thereof varies according to
the stress change, and the mechanical vibration of the needle point
13 is detected as an electric signal.
On the other hand, the other semiconductor piezo-resistance
elements 37, 37' undergo a rotational force about the dotted line
axis as indicated by the arrows 44. Therefore, a bending stress is
not substantially imposed on the semiconductor piezo-resistance
elements 37, 37' and hence a change in internal resistance is very
minor.
It will be obvious that the above-described condition will be
reversed when the needle point 13 vibrates in a direction at right
angles to the arrows 40.
Besides the construction shown in FIG. 7, the
semiconductor-deposited film element may be of the construction as
shown in FIG. 8 wherein each of the arms 29, 30 of the insulating
film base plate 19 is provided with a pair of electrodes 45, 45' or
46, 46' and a semiconductor piezo-resistance element 47 or 48; or
of the construction as shown in FIG. 9 wherein a notch 49 is formed
in the insulating film base plate 19 extending to the central
portion of the latter and semiconductor piezo-resistance element
51, 52 are formed on the arms 29, 30 respectively, with one ends
connected to a common electrode 50 and the other ends connected to
electrodes 53, 54 respectively, said electrodes 53, 54 being
extended so as to facilitate connection with the terminal rods; or
of any other construction.
Another embodiment of the pickup cartridge according to the
invention will be described with reference to FIGS. 10, 11 and 12.
In these Figures, reference numeral 113 designates a needle point
which traces the sound track of a photograph record to detect a
vibration and 114 designates a cantilever to transmit the vibration
of the needle point 113 to the mechano-electrical transducing unit,
said cantilever being made of a light alloy material. Reference
numeral 115 designates a holder made of an elastic material and
adapted to hold a semiconductor-deposited film element between it
and a supporting member to be described later. The holder 115 is
provided with an axial hole 116 through the center thereof.
Reference numeral 117 designates the semiconductor-deposited film
element comprising a cross-shaped insulating film substrate 123
having four arms 118, 119, 120 and 121 lying in the same plane at
substantially right angles to each other, and provided with a
through-hole 122 at the center thereof; and two semiconductor
piezo-resistance elements 124 and 124', 125 and 125', 126 and 126'
or 127 and 127' provided side by side on each of said arms, with
one ends thereof connected to a common electrode 128, 129, 130 or
131 and the other ends connected to electrodes 132 and 132', 133
and 133', 134 and 134' or 135 and 135' respectively.
Reference numeral 136 designates a cylindrical support member
having a stepped, reduced diameter portion 137 at one end thereof.
The reduced diameter portion 137 is provided therein with a hole
138 for receiving the inner end of the cantilever 114 therein.
Reference numeral 139 designates an insulating mounting block
serving simultaneously as a cartridge housing. The insulating
mounting block 139 has recesses 140, 141 in the opposite end faces
thereof, and an axial hole 143 extending between the centers of
said recesses 140, 141 for receiving the supporting member 136
therein. Terminal rods 143 are embedded in the mounting block 139
with the opposite ends thereof projecting into the recesses 140,
141 respectively and a terminal plate 145 having terminal rods 144
extending therethrough is securely fitted in the recess 141, said
terminal rods 144 being connected to the ends of the terminal rods
143 projecting into said recess 141 respectively.
The pickup cartridge of the construction described above is
assembled in the following manner: First of all, the reduced
diameter portion 137 of the supporting member 136 is inserted into
the through-hole 122 formed in the insulating film substrate 119 of
the semiconductor-deposited film element 117 and the holder 115 is
fitted on said reduced diameter portion 137, with the latter
received in the axial hole 116 of the former, thereby to clamp the
semiconductor-deposited film element 117 between said holder 115
and the shoulder 146 connecting the reduced diameter potion with
the larger diameter portion of the supporting member 136.
Then, the cantilever 114 is inserted into the axial hole 138 of the
supporting member 136 with pressure and the supporting member 136
carrying the cantilever 114 is inserted into the hole 142 of the
insulating mounting block 139 and secured therein as by an adhesive
or the like.
In the assembled state, the arms 118, 119, 120 and 121 of the
semiconductor-deposited film element 117 are positioned within the
recess 140 of the insulating mounting block 139 and said recess 140
closed with a front cap 147 is filled with a flowable viscous
material 148. Therefore, the arms 118, 119, 120 and 121 are
supported by the cartridge housing, composed of the insulating
mounting block 139 and the front cap 147, through the flowable
viscous material 148.
On the other hand, the electrodes 132, 132'; 133, 133'; 134, 134'
and 135, 135' on the semiconductor-deposited film element 117 are
connected with the terminal rods 143 respectively in this
state.
The operation of the pickup cartridge constructed as described
above will be briefly explained hereunder with reference to FIG.
12. The semiconductor-deposited film element 117 is integral with
the cantilever 114. Therefore, a vibration transmitted to the
cantilever from the needle point 113 is propagated in four
directions from the supporting member 136 in a cross shape.
When a vibration as indicated by the arrows 149 is given to the
needle point 113, said needle point 113 and the cantilever 114
vibrate in the same direction as that indicated by the arrows 149,
with the center of vibration located at the supporting member
136.
As the cantilever 114 vibrates in the manner described, the arms
118 and 120 of the semiconductor-deposited film element 117, which
are parallel to the arrows 149, undergo a vibration as indicated by
the arrows 150, 151 respectively and hence the semiconductor
piezo-resistance elements 124, 124' and 126, 126' formed on said
respective arms 118, 120 are subjected to a bending stress caused
by the braking force of the flowable viscous material 148. The
resultant changes in the internal resistances of the semiconductor
piezo-resistance elements 124, 124' and 126, 126' are detected
through the terminal rods 144, which correspond to the vibration of
the needle point 113.
On the other hand, the other arms of the semiconductor-deposited
film element 117, i.e. the arms 119 and 121 extending perpendicular
to the arrows 149, undergo a rotational force about the dotted line
axis as indicated by the arrows 142, 153. Therefore, the
semiconductor piezo-resistance elements 125, 125' and 127, 127'
provided on these arms 119, 121 are subjected to substantially no
bending stress and, therefore, a change in internal resistance
thereof is very small.
Now, when the needle point 113 is caused to vibrate in the
direction of the arrows 154 perpendicular to the direction of
arrows 149, the internal resistances of the semiconductor
piezo-resistance elements 125, 125' and 127, 127' are varied
largely and those of the semiconductor piezo-resistance element
124, 124' and 126, 126' are not substantially varied, as will be
readily understood.
FIGS. 13 and 14 show other forms of the semiconductor-deposited
film element 117. In the form shown in FIG. 13, each of the four
arms 118, 119, 120 and 121 of the cross-shaped insulating film base
plate 123 is provided with one semiconductor piezo-resistance
element 155, 156, 157 or 158 and its electrodes 159, 159'; 160,
160'; 161, 161' or 162, 162'. The form shown in FIG. 14 is similar
to that of FIG. 13 in that each of the arms 118, 119, 120 and 121
is provided with one semiconductor piezo-resistance element 155,
156, 157 or 158, but is different from the latter in that one ends
of the semiconductor piezo-resistance elements 156, 157 are
connected to a common electrode 163 and one ends of the other
semiconductor piezo-resistance elements 158, 155 are connected to
another common electrode 164.
Still another embodiment of the pickup cartridge according to the
invention will be described in detail with reference to FIGS. 15,
16 and 17. Referring to FIGS. 15, 16 and 17, reference numeral 213
designates a needle point to detect a vibration by tracing the
sound track of a phonograph record and 214 designates a cantilever
made of a light alloy material and adapted to transmit the
vibration of the needle point 213 to a mechano-electrical
transducer unit. Reference numeral 215 designates an ultrafine wire
to constitute a center of vibration when the needle point 213 and
the cantilever 214 vibrate according to the sound track. The
ultrafine wire 215 is fixedly supported by a spacer 216 fitted into
the inner end of the cantilever 214. Reference numeral 217
designates a supporting member to secure the ultrafine wire 215 to
the main body of the cartridge, i.e. a mounting block. The
supporting member 217 is fixed to the ultrafine wire 215, with a
slight gap of 1 mm or smaller being maintained between it and the
inner end of the cantilever 214, so as to provide for free
vibration of the needle point 213 and the cantilever 214 about said
ultrafine wire 215.
Reference numeral 218 designates a supporting member to hold
between it and a damping support 220 of an elastic material a
semiconductor- deposited film element having layers of
semiconductor deposited thereon.
As shown in the front view of FIG. 18, the semiconductor-deposited
film element 219 comprises an insulating film substrate 224 having
two integral arms 221, 222 arranged at substantially right angles
to each other and having a through-hole 223 bored at the root
portions of said arms, and on each arm 221 or 222 are formed tow
semiconductor piezo-resistance element 225, 225' or 226,
226.degree. side by side by vacuum evaporation, with one ends
thereof connected to electrodes 227, 228 or 229, 230 and the other
ends connected to a common electrode 231 or 232. Namely, the
semiconductor piezo-resistance elements 225, 225' or 226, 226' are
connected with each other in series. The arms 221 and 222 are
flexed at their roots in the same direction to extend parallel to
each other as best shown in FIG. 17.
Reference numeral 233 designates an insulating mounting block which
can be split into two pieces, i.e. a main body 234 and a fragment
239, and which is cylindrical in shape in the assembled state. The
inside of the main body 234 of the mounting block is formed with
two axially extending surfaces perpendicular to each other and one
ends of said surfaces are recesses as at 235, 236. Slightly
inwardly of the other end of the main body 234 is formed a cavity
237 and a through-hole 238 is bored axially centrally from one end
face of the main body 234 to open in said cavity 237.
On the other hand, the fragment 239 is so shaped that when it is
fitted on the main body 234, the recessed portions 235, 236 of the
main body open only in one end face of the mounting block.
Reference numeral 240 designates terminal rods embedded in the
fragment 239 of the mounting block 233, with one ends thereof
projecting from one end face of said fragment and the other ends
projecting inwardly at locations slightly inwardly of the other end
face of the same. Reference numeral 241 designates terminal rods
extending through the end wall of the main body 234 for connection
with an external element.
The pickup cartridge of the construction described above is
assembled in the following manner. First of all, the holder 218 is
fitted on the inner end of the cantilever 214 and then the
semiconductor-deposited film element 219 is mounted on the
cantilever 214, with the latter extending through the through-hole
223 formed in the insulating film substrate 224 of the former.
Thereafter, the damping support material 220 is mounted in such a
manner as to bridge the inner end of the cantilever 214 and the
supporting member 217, whereby the semiconductor-deposited film
element 219 is clamped between the holder 218 and the damping
support 220.
Upon completion of this, the supporting member 217 is inserted into
the hole 238 of the main body 234 of the mounting block 233, while
simultaneously inserting the arms 221, 222 of the
semiconductor-deposited film element 219 into the cavities 235, 236
respectively while keeping them out of contact with the inner walls
of said cavities. The supporting member 214 thus inserted is
secured in the hole 238 of the main body 234 as by means of a screw
242. In this case, the electrodes 227, 228, 229 and 230 of the
semiconductor-deposited film element 219 are connected with the
terminal rods 240 and said terminal rods 240 are in turn connected
with the terminal rods 241 respectively.
After insertion of the arms 221, 222 of the semiconductor-deposited
film element 219, the cavities 235, 236 are filled with a flowable
viscous material 243 and said arms 221, 222 are supported by the
mounting block 233 through said flowable viscous material 243.
The operation of the pickup cartridge thus assembled will be
briefly explained hereunder. Since the semiconductor-deposited film
element 219 is fixed at substantially the terminal end of the
cantilever 214, a vibration transmitted from the needle point 213
is propagated in the directions of a V-shape. When a vibration is
given to the needle point 213 as indicated by the arrow 244 in FIG.
17, said needle point 213 and the cantilever 214 vibrate in the
same direction as that of the arrow 244 with respect to the center
of vibration constituted by the ultrafine wire 215. Therefore, the
arm 222 of the insulating film base plate 224 of the
semiconductor-deposited film element 219, which lies in a plane
crossing the arrow 244, is caused to vibrate and the semiconductor
piezo-resistance elements 226, 226' on said arm 222 undergo a
bending stress by being braked by the flowable viscous material
243. As a result, the internal resistances of the semiconductor
piezo-resistance elements 226, 226' are varied according to the
vibration of the needle point 213 and the variations in the
internal resistances are detected through the terminal rods
241.
In this case, the other semiconductor piezo-resistance elements
225, 225' undergo the stress of vibration in the direction of the
plane in which they lie and, therefore, no change occurs in the
internal resistances thereof.
On the other hand, when the needle point 213 is vibrated in the
direction of the arrow 246 which is perpendicular to the direction
of the arrow 244, the semiconductor piezo-resistance elements 225,
225' undergo a bending stress and the semiconductor
piezo-resistance element 226, 226' do not undergo a bending stress
at all. Therefore, the internal resistance changes of the
semiconductor piezo-resistance element 225, 225' are detected.
Although in the embodiment described above, the two sets of the
mechano-electrical transducing means provided on the semiconductor-
deposited film element are each composed of two semiconductor
piezo-resistance elements, the same may be composed of only one
semiconductor piezo-resistance element or may be of any other
construction.
Now, a description will be given on a microphone to which the
present invention is applied.
FIGS. 19 and 20 exemplify microphones incorporating the
semiconductor stress converting apparatus based upon the principle
described hereinabove. Referring first to FIG. 19, the microphone
shown is of the same construction as that of FIG. 2 wherein the
holder 4 is to be displaced. Reference numeral 314 designates a
diaphragm which is vibrated by a sound. The diaphragm 314 is
connected to a semiconductor-deposited film element 315. The
opposite edges of the semiconductor-deposited film element 315 are
respectively supported in recesses 318, 318' through a flowable
viscous material 319, 319', which recesses are formed opposite to
each other in the inner peripheral wall of a central hole 317
formed in a mounting block 316. Reference numeral 320 designates a
casing in which a protecting perforated plate 321 and the
respective elements described above are mounted.
The microphone shown in FIG. 20 is of the same type as that of FIG.
2 wherein the holder 5 is to be displaced. In FIG. 20, similar
parts are indicated by same numerals. A diaphragm 314 has fixed
thereto a movable member 323 which defines recesses 322, 322' on
both sides thereof, while a fixed member 324 has two semiconductor
deposited film elements 315, 315' fixed thereto at one ends
thereof, and the other ends of said semiconductor-deposited film
elements are supported in said recesses 322, 322' respectively
through a flowable viscous material 319, 319'.
* * * * *