U.S. patent number 3,859,617 [Application Number 05/399,150] was granted by the patent office on 1975-01-07 for turnable, contactless variable resistor.
This patent grant is currently assigned to Matsushita Electric Industrial Co., Ltd.. Invention is credited to Shunji Minami, Shunzo Oka.
United States Patent |
3,859,617 |
Oka , et al. |
January 7, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
TURNABLE, CONTACTLESS VARIABLE RESISTOR
Abstract
A turnable, contactless variable resistor is provided consisting
of a light source and a photoconductive cell, capable of operation
without producing noise and wear as distinguished from conventional
turnable variable resistors having mechanical contact.
Inventors: |
Oka; Shunzo (Osaka,
JA), Minami; Shunji (Osaka, JA) |
Assignee: |
Matsushita Electric Industrial Co.,
Ltd. (Kadoma-shi, Osaka-fu, JA)
|
Family
ID: |
14593005 |
Appl.
No.: |
05/399,150 |
Filed: |
September 20, 1973 |
Foreign Application Priority Data
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Sep 26, 1972 [JA] |
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47-112689[U] |
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Current U.S.
Class: |
338/15;
250/214PR; 257/E31.106 |
Current CPC
Class: |
H01L
31/164 (20130101) |
Current International
Class: |
H01L
31/16 (20060101); H01c 007/08 () |
Field of
Search: |
;338/15,18
;250/211K,211R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Albritton; C. L.
Attorney, Agent or Firm: Burgess, Ryan & Wayne
Claims
What is claimed is:
1. A turntable, contactless variable resistor comprising:
an opaque disk having a shaft that is rotatable about a given
axis;
an opaque upper supporting plate having an opening therethrough for
transmitting light and a bearing for the free turning of said disk
about the shaft axis;
a light source fixed to the upper supporting plate and completely
on one side thereof;
an opaque lower supporting plate having an opening therethrough for
transmitting light from the light source disposed coaxially with
the hole on said upper supporting plate;
a photoconductive cell fixed to the opening of said lower
supporting plate and completely one one side thereof; and
said disk having an opening disposed between said upper and lower
supporting plates at a radial position corresponding to the radial
position of the openings in said supporting plates said supporting
plates being joined as one body with said one side on the outside
of said body, and the conducting resistance of said photoconductive
cell varying by means of a changing amount of light passing through
the openings by turning said rotatable shaft.
2. A turnable, contactless variable resistor as defined in claim 1
wherein, a photoconductive cell is attached on the opening of said
upper supporting plate and a light source on the opening of said
lower supporting plate.
3. A turnable, contactless variable resistor as defined in claim 1
wherein, the opening of the disk is a large comma like shape, whose
radial distance varies with the angular displacement of the disk
about the shaft axis.
4. A turntable, contactless variable resistor as defined in claim 1
wherein:
the upper supporting plate has a second opening for transmitting
light;
the lower supporting plate has a second opening located coaxially
with said corresponding opening on said upper supporting plate;
and
a second light source and a second photoconductive cell are
attached in positions corresponding to those associated with said
first light source and photoconductive cell;
whereby the resistances of the first and second photoconductive
cells may be varied at the same time in response to rotation of the
shaft.
5. A turntable, contactless variable resistor as defined in claim 4
wherein, the opening of the disk is a large comma-like shape, whose
width measured radially varies with angular displacement of the
disk about the shaft axis.
Description
BACKGROUND OF THE INVENTION:
This invention relates to a turnable, contactless variable
resistor, particularly one having a photoconductive cell disposed
opposite the light source, and being provided with a disk having a
slit or an opening for varying the amount of light from the source
to the photoconductive cell.
In general, a variable resistor has a horse shoe shaped resistance
body on which a contact slide is provided; consequently, the life
of the resistance body is shortened due to wear by the sliding of
the contact on the resistance body.
SUMMARY OF INVENTION:
In accordance with the invention, a light source and a
photoconductive cell are disposed facing each other, and
therebetween is placed a disk having a large comma like opening
which controls the amount of light from the light source to the
photoconductive cell.
The object of this invention is to provide a turnable, contactless
variable resistor having a configuration similar to that of a
conventional variable resistor.
Another object of this invention is to provide a turnable,
contactless variable resistor which does not generate any noise as
does the conventional variable resistor.
Still another object of this invention is to provide a turnable,
contactless variable resistor which does not deteriorate due to
wear in the course of operation in a manner similar to that of a
conventional variable resistor.
Further objects and the features of this invention will become
apparent to those skilled in the art as the description thereof
proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be more readily described by reference to
the accompanying drawings in which:
FIG. 1 is the a cross sectional view of the embodiment of this
invention.
FIG. 2 is a perspective view of the embodiment of this
invention.
FIG. 3 is a plan view of the turnable disk of the embodiment of
this invention.
FIG. 4 is another embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to figures, disk 2 having a rotating shaft 1 on one side
of the disk is disposed between an upper supporting plate 3 and a
lower supporting plate 4. On the disk is provided a large
comma-shaped opening whose center line is equi-distant from the
center of the disk and whose width measured radially varies with
the angular position of the disk in accordance with the desired
output characteristic of the device. The center line of the opening
is also between the centers of holes 6 and 8 on the upper
supporting plate 3 and on the lower supporting plate 4. The light
source 7 is placed on the hole 6 on the upper supporting plate. The
leakage of light from the light source is prevented by sealing the
contact between the light source 7 and the upper supporting plate
by means of like material resin like material (not shown). The
photoconductive cell 9 of CdS or CdSe or the like is placed beneath
the hole 8 on the lower supporting disk. To prevent light leakage
from the contact of the photoconductive cell and the lower
supporting plate, the contact is sealed with a resin-like material
(not shown). The two supporting plates are also sealed and made as
one body.
Now the operation of the turnable, contactless variable resistor is
described. When the rotating shaft 1 is turned, the amount of light
from the light source 7 is varied by the opening 5; and the amount
of the light from the light source to the photoconductive cell
changes according to the area of opening. The resistance of the
photoconductive cell changes with the amount of the light received.
Thus, with the turn of the shaft 1, this turnable contactless
variable resistor can be used as a variable resistor.
In FIG. 4 is shown another embodiment of this invention. On the
upper supporting plate are disposed two holes 6 and 10. Beneath the
hole 10 is another hole 11 on the lower supporting plate. On the
upper hole 10 is placed another light source 12 and beneath the
hole 11 on the lower supporting plate is another photoconductive
cell 13. The contacts between them are sealed as in the first
embodiment (Seal is not shown). With the turn of the shaft, the
resistances of two photoconductive cells can be varied. Thus, this
embodiment has the configuration of two contactless variable
resistors.
* * * * *