US1697451A - Light-sensitive electric device - Google Patents

Light-sensitive electric device Download PDF

Info

Publication number
US1697451A
US1697451A US276162A US27616228A US1697451A US 1697451 A US1697451 A US 1697451A US 276162 A US276162 A US 276162A US 27616228 A US27616228 A US 27616228A US 1697451 A US1697451 A US 1697451A
Authority
US
United States
Prior art keywords
light
sensitive
cell
temperature
film
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US276162A
Inventor
Baird John Logie
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Baird Television Ltd
Original Assignee
Baird Television Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Baird Television Ltd filed Critical Baird Television Ltd
Application granted granted Critical
Publication of US1697451A publication Critical patent/US1697451A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors

Definitions

  • This invention is for improvements in or relating to light-sensitive electric devices of the type in which light-sensitive materials such as selenium, thallium sulphide, carbon and so forth are used, these beingsubstances which chan e their electrical resistance when expose to radiant energy; the object of the invention is to provide a construction whereby the time-lag of the response of the device is reduced or eliminated, and in-some instances the device is rendered more sensitive.
  • the invention accordingly comprises a light-sensitive cell wherein the light-sensitive substance is in the form of a thin film.
  • the thin film aforesaid of the-light-sensitive substance may, according to another feature of this invention, be made so thin that it cannot support itself, and in this case the film is disposed on an insulating support which is itself of theminimum thickness necessary to provide the mechanical support'for the film.
  • 80 the thin film may conveniently be'ohtained by sputtering it 'on the supporting element.
  • the electrical resistance of selenium and other light-sensitive substances varies with its temperature, and the temperature coefficient itself varies, being positive over some ranges of temperature and negative over others: this variation is independent of the resistance variation due to the action of light,
  • the present invention therefore 40 comprises further the combination with a light-sensitive cell, of means for controlling its temperature whereby it may be operated in circumstances in which the thermal effect is additive to the optical eflect when radiation falls on the cell, and the sensitivity is thereby considerably increased.
  • This invention also comprises the combination with a light-sensitive cell, its circuits and amplifying devices, of means for controlling the temperature of some or all of these parts in order that parasitic currents in the conductors may beaminimized by maintaining them at a low temperature.
  • This invention also comprises a construc- 56 tion of light-sensitive cell in which a sub- A Bnrrrsn COMPANY.
  • stantially closedchamber has a light-sensitive substance dis in the form of a thin coating onits inner surface, and preferably extending all overthat surface: this chamber has an opening through which radlation can enter 1t to impinge on the lightsensitive substance and be entirely absorbed thereby.
  • a light-sensitive cell may be constituted by a light-sensitive fluid or liquid in the form of a thin layer enclosed between two transparent plates or one opaque and.
  • F1gure 1 is a perspective view showing a thin film of light-sensitive material mounted on a supporting element;
  • Flgure 2 shows an alternative construction in which the light-sensitive element is self-supporting
  • Figure 3 is a sectional view showing diagrammatically the ⁇ cell adapted for temperature control.
  • FIGS 4 to 8 show diagrammatically various constructions of light-sensitive cell.
  • a very thin sheet of mica or other insulating material 10' has a thin film of selenium sputtered on to it, for instance, by'means of an electric are, using the material selenium as one electrode. Electrical contacts are provided at the two ends of the strip in any convenient manner, as for example by spring clips 12.-
  • the mica or other insulating support is made of the minimum thickness which will provide suflicient mechanical strength. and rigidity, and the film of selenium is so thin that it would not be mechanically self-supporting.
  • a single large crystal of selenium may have conductors attached to its opposite ends 13, 14, and the intervening material is ground away as at'15 so as to, make it as thin as is consistent with the necessary 6 temperature.
  • Figure 3 illustrates diagrammatically a light-sensitive j cell in which provision is made for regulating the temperature. It comprises a light-sensitive element 16 which may for example be similar to that illustrated in Figure 1, and it is enclosed in a double-walled chamberlT. A glass, quartz or other transparent window 18 is provided in this chamber to permit the entry of the radiant energy which is to act on the. lightsensitive material. The space between the double walls may be used for. circulating a cooling or heating fluid through pipe-connections 19, or alternatively or additionally a suitable resistance element 20 may be provided for electrically heating the vessel.
  • This construction provides a device in which the temperature of the light-sensitive g element 16 can be positively controlled so that it is operated at the most advantageous When light or other radiant energy is to be measured by means of a selenium or similar light-sensitive cell, it is advantageous that the whole of the energy falling on the light-sensitive material should be absorbed thereby, and none lost by reflection or diffusion, as the sensitivity is thereby increased. 7
  • the light-sensitive cell may be constructed as illustrated dia- 4 the whole of its interior with the light-sensigrammatically in Figure 4, in which a sub-' stantially closed chamber 21 is coated over tive material.
  • a small opening 22 is provided to admit the radiation and with this arrangement it is ensured that all the energy entering the chamber is absorbed, because any energy reflected from the surface is subjected to repeated reflection until it is all absorbed.
  • the current which is varied by the variation in resistance of the light-sensitive material, is arranged to traverse the whole of the material, the circuitbeing established by means of two leading-1n wires 23, 24 which -are connected to two points on the inner coating spaced apart, for example diametrically opposite one another.
  • the chamber 25 maybe made of metal or other conducting material coated on its'inner surface with a layer 26 of light-sensitive material.
  • The. aperture 27 by which the light enters the cell is closedby glass, quartz or other material transparent to the radiation which is-being used.
  • the current 1s made to traverse the thickness of the layer or film 26 in a radial direction, one pole of the cell being constituted by the chamber 25 to which a connection 37 is made, and the other by a centrally-disposed nium is used as the end wall of a vessesl 30.
  • One connection may be made directly to the outside surface of the plate 29, and the vessel is filled with a conducting liquid in which a terminal 31 constitutes the other pole of the cell.
  • the walls of the vessel and the liquid are of course: such as to be transparent to the radiation-which is being used.
  • the liquid on that side of the partition 32 whichis not exposed to the radiation may be any suitable conducting liquid, opaque to means 'for controlling their temperature during working in order that they may be caused to operate over a suitable temperature range is which the maximum sensitivity is obtained and parasitic currents are reduced.
  • the whole or any desired part of the circuits associated with the cell are preferably also provided with means for maintaining them at a low temperature for the purpose of avoiding or minimizing parasitic currents.
  • the temperature control of the whole apparatus may be effected in any desired manner, for example by enclosing the whole of the apparatus in a suitable chamber whereof the temperature can be controlled.
  • a resistance unit variable by the action of light comprising an opaqueinsulating hollow body provided with an aperture therein for the passage of light, and having a thinfilm of light sensitive material. deposited on the interior thereof.
  • a resistance unit variable by the action: of light comprising an opaque insulating hollow body provided with an a erture therein for the passage of light, and aving a thin film of light sensitive material deposited on the interior thereof, and means for controlling the temperature of said body.
  • a resistance unit variable by the action of light comprising an opaque insulating hollow body provided with an aperture therein, and having 'a film of light sensitive material deposited on the interior thereof, a transparent member forming aclosure for said aperture for permitt-in passage of light to the interior of said body and for retaining conducting fluid therein, an electrode extending into said conducting fluid, and anelectrical connection to said light sensitive film.
  • a resistance unit variable by the action of'light comprising an opaque insulating hollow body provided with an aperture therein, and having a film'of light sensitive material deposited on the interior thereof, a
  • transparent member forming a closure for said aperture for permitting passage of light to the interior of said body and for retaining a conducting fluid therein, an electrode extending into said conducting fluid, a ter-- of light comprising an opaque hollow bodyof substantially spherical shape provided with'an aperture therein for the passage of light, and having a film of light-sensitive material deposited on the major portion of the interior thereof.

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)

Description

Jan. 1, 1929. v
J. L. BAIRD LIGHT SENSITIVE ELECTRIC DEVICE Filed Ma 8, 1928 IIYYFITM I IS A w Patented Jan. ;1,- 1929.
UNITED STATES- PATENT oFFlCEa JOHN Loam BAIBD, or LONDON, ENGLAND,- assIeNon r 'rnmivrsroN Lnrrrnn, or
LONDON, ENG AND;
men'r-saNsrrrvn Application filed Kay 8, 1928, Serial No.
I This invention is for improvements in or relating to light-sensitive electric devices of the type in which light-sensitive materials such as selenium, thallium sulphide, carbon and so forth are used, these beingsubstances which chan e their electrical resistance when expose to radiant energy; the object of the invention is to provide a construction whereby the time-lag of the response of the device is reduced or eliminated, and in-some instances the device is rendered more sensitive.
The invention accordingly comprises a light-sensitive cell wherein the light-sensitive substance is in the form of a thin film.
which provides the maximum active area with the minimum weight and heat capacity, so that any response of the material due to change in temperature may, where suitable, be utilized in a'ddition'to the photoelectric effect. I
The thin film aforesaid of the-light-sensitive substance, may, according to another feature of this invention, be made so thin that it cannot support itself, and in this case the film is disposed on an insulating support which is itself of theminimum thickness necessary to provide the mechanical support'for the film. With this arrangement, 80 the thin film may conveniently be'ohtained by sputtering it 'on the supporting element. The electrical resistance of selenium and other light-sensitive substances varies with its temperature, and the temperature coefficient itself varies, being positive over some ranges of temperature and negative over others: this variation is independent of the resistance variation due to the action of light, The present invention therefore 40 comprises further the combination with a light-sensitive cell, of means for controlling its temperature whereby it may be operated in circumstances in which the thermal effect is additive to the optical eflect when radiation falls on the cell, and the sensitivity is thereby considerably increased. This invention also comprises the combination with a light-sensitive cell, its circuits and amplifying devices, of means for controlling the temperature of some or all of these parts in order that parasitic currents in the conductors may beaminimized by maintaining them at a low temperature.
This invention also comprises a construc- 56 tion of light-sensitive cell in which a sub- A Bnrrrsn COMPANY.
nnnc'rarc mivrcn.
278,162, t in Great-Britain-Iay 7, i927.-
stantially closedchamber has a light-sensitive substance dis in the form of a thin coating onits inner surface, and preferably extending all overthat surface: this chamber has an opening through which radlation can enter 1t to impinge on the lightsensitive substance and be entirely absorbed thereby. I y
According-to another feature of this invention a light-sensitive cell may be constituted by a light-sensitive fluid or liquid in the form of a thin layer enclosed between two transparent plates or one opaque and.
one transparent plate.
In the accompanying drawings, which illustrate this invention diagrammatically F1gure 1 is a perspective view showing a thin film of light-sensitive material mounted on a supporting element;
Flgure 2 shows an alternative construction in which the light-sensitive element is self-supporting;
Figure 3 is a sectional view showing diagrammatically the {cell adapted for temperature control; and
Figures 4 to 8 show diagrammatically various constructions of light-sensitive cell.
In the construction illustrated in" Figure 1, a very thin sheet of mica or other insulating material 10' has a thin film of selenium sputtered on to it, for instance, by'means of an electric are, using the material selenium as one electrode. Electrical contacts are provided at the two ends of the strip in any convenient manner, as for example by spring clips 12.- The mica or other insulating support is made of the minimum thickness which will provide suflicient mechanical strength. and rigidity, and the film of selenium is so thin that it would not be mechanically self-supporting.
In the construction illustrated in Figure 2, a single large crystal of selenium may have conductors attached to its opposite ends 13, 14, and the intervening material is ground away as at'15 so as to, make it as thin as is consistent with the necessary 6 temperature.
strip is but small, the heat-capacity of the terminals is not of such great importance.
Figure 3. illustrates diagrammatically a light-sensitive j cell in which provision is made for regulating the temperature. It comprises a light-sensitive element 16 which may for example be similar to that illustrated in Figure 1, and it is enclosed in a double-walled chamberlT. A glass, quartz or other transparent window 18 is provided in this chamber to permit the entry of the radiant energy which is to act on the. lightsensitive material. The space between the double walls may be used for. circulating a cooling or heating fluid through pipe-connections 19, or alternatively or additionally a suitable resistance element 20 may be provided for electrically heating the vessel. This construction provides a device in which the temperature of the light-sensitive g element 16 can be positively controlled so that it is operated at the most advantageous When light or other radiant energy is to be measured by means of a selenium or similar light-sensitive cell, it is advantageous that the whole of the energy falling on the light-sensitive material should be absorbed thereby, and none lost by reflection or diffusion, as the sensitivity is thereby increased. 7
With this object in view the light-sensitive cell may be constructed as illustrated dia- 4 the whole of its interior with the light-sensigrammatically in Figure 4, in which a sub-' stantially closed chamber 21 is coated over tive material. A small opening 22 is provided to admit the radiation and with this arrangement it is ensured that all the energy entering the chamber is absorbed, because any energy reflected from the surface is subjected to repeated reflection until it is all absorbed.
In this arrangement, the current, which is varied by the variation in resistance of the light-sensitive material, is arranged to traverse the whole of the material, the circuitbeing established by means of two leading- 1n wires 23, 24 which -are connected to two points on the inner coating spaced apart, for example diametrically opposite one another.
In the construction illustrated in Figure 5 the chamber 25 maybe made of metal or other conducting material coated on its'inner surface with a layer 26 of light-sensitive material. The. aperture 27 by which the light enters the cell is closedby glass, quartz or other material transparent to the radiation which is-being used. In this case the current 1s made to traverse the thickness of the layer or film 26 in a radial direction, one pole of the cell being constituted by the chamber 25 to which a connection 37 is made, and the other by a centrally-disposed nium is used as the end wall of a vessesl 30.
One connection may be made directly to the outside surface of the plate 29, and the vessel is filled with a conducting liquid in which a terminal 31 constitutes the other pole of the cell. The walls of the vessel and the liquid are of course: such as to be transparent to the radiation-which is being used. A modified construction of such a Cell'is illustrated in Figure 7, in which the selenium vplate32 constitutes a partition in a vessel separating two bodies of liquid which'constitute the electrodes of the cell. The liquid on that side of the partition 32 whichis not exposed to the radiationmay be any suitable conducting liquid, opaque to means 'for controlling their temperature during working in order that they may be caused to operate over a suitable temperature range is which the maximum sensitivity is obtained and parasitic currents are reduced. Also, the whole or any desired part of the circuits associated with the cell, such for example, as the amplifying devices are preferably also provided with means for maintaining them at a low temperature for the purpose of avoiding or minimizing parasitic currents. The temperature control of the whole apparatus may be effected in any desired manner, for example by enclosing the whole of the apparatus in a suitable chamber whereof the temperature can be controlled.
I claim 1. A resistance unit variable by the action of light, comprising an opaqueinsulating hollow body provided with an aperture therein for the passage of light, and having a thinfilm of light sensitive material. deposited on the interior thereof. f
A resistance unit variable by the action: of light, comprising an opaque insulating hollow body provided with an a erture therein for the passage of light, and aving a thin film of light sensitive material deposited on the interior thereof, and means for controlling the temperature of said body. 3. A resistance unit variable by the action of light, comprising an opaque insulating hollow body provided with an aperture therein, and having 'a film of light sensitive material deposited on the interior thereof, a transparent member forming aclosure for said aperture for permitt-in passage of light to the interior of said body and for retaining conducting fluid therein, an electrode extending into said conducting fluid, and anelectrical connection to said light sensitive film.
4. A resistance unit variable by the action of'light, comprising an opaque insulating hollow body provided with an aperture therein, and having a film'of light sensitive material deposited on the interior thereof, a
transparent member forming a closure for said aperture for permitting passage of light to the interior of said body and for retaining a conducting fluid therein, an electrode extending into said conducting fluid, a ter-- of light comprising an opaque hollow bodyof substantially spherical shape provided with'an aperture therein for the passage of light, and having a film of light-sensitive material deposited on the major portion of the interior thereof.
In testimony whereof I aflix mysignature.
' JOHN LOGIE BAIRD.
US276162A 1927-05-07 1928-05-08 Light-sensitive electric device Expired - Lifetime US1697451A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB653827X 1927-05-07
GB1697451X 1927-05-07

Publications (1)

Publication Number Publication Date
US1697451A true US1697451A (en) 1929-01-01

Family

ID=59713397

Family Applications (1)

Application Number Title Priority Date Filing Date
US276162A Expired - Lifetime US1697451A (en) 1927-05-07 1928-05-08 Light-sensitive electric device

Country Status (2)

Country Link
US (1) US1697451A (en)
FR (1) FR653827A (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2426494A (en) * 1943-12-20 1947-08-26 Rca Corp Heat detection device
US2442396A (en) * 1943-05-05 1948-06-01 Mississippi Valley Res Lab Inc Magneto-optic light rotator
US2448517A (en) * 1944-02-09 1948-09-07 Univ Northwestern Photocell
US2572079A (en) * 1947-03-13 1951-10-23 Standard Telephones Cables Ltd Radiation-sensitive cells and method of making same
US2606215A (en) * 1948-11-26 1952-08-05 Weston Electrical Instr Corp Encased and hermetically sealed photocell
US2674677A (en) * 1951-03-17 1954-04-06 Comb Control Corp Photoconductive cell
US2779811A (en) * 1952-04-21 1957-01-29 Vitro Corp Of America Photo-cell construction
US2898525A (en) * 1955-03-15 1959-08-04 Gen Electric Light responsive system
US2918584A (en) * 1955-10-20 1959-12-22 Burroughs Corp Light responsive electrical device
US4313024A (en) * 1977-04-05 1982-01-26 Horne William E Conversion of solar to electrical energy
US6018124A (en) * 1998-01-15 2000-01-25 Lidow; Nicholai Hart Selenium photo generator cell with fluid top electrode

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2442396A (en) * 1943-05-05 1948-06-01 Mississippi Valley Res Lab Inc Magneto-optic light rotator
US2426494A (en) * 1943-12-20 1947-08-26 Rca Corp Heat detection device
US2448517A (en) * 1944-02-09 1948-09-07 Univ Northwestern Photocell
US2572079A (en) * 1947-03-13 1951-10-23 Standard Telephones Cables Ltd Radiation-sensitive cells and method of making same
US2606215A (en) * 1948-11-26 1952-08-05 Weston Electrical Instr Corp Encased and hermetically sealed photocell
US2674677A (en) * 1951-03-17 1954-04-06 Comb Control Corp Photoconductive cell
US2779811A (en) * 1952-04-21 1957-01-29 Vitro Corp Of America Photo-cell construction
US2898525A (en) * 1955-03-15 1959-08-04 Gen Electric Light responsive system
US2918584A (en) * 1955-10-20 1959-12-22 Burroughs Corp Light responsive electrical device
US4313024A (en) * 1977-04-05 1982-01-26 Horne William E Conversion of solar to electrical energy
US6018124A (en) * 1998-01-15 2000-01-25 Lidow; Nicholai Hart Selenium photo generator cell with fluid top electrode
US6078007A (en) * 1998-01-15 2000-06-20 Lidow; Nicholai Hart Selenium photo generator cell with fluid top electrode

Also Published As

Publication number Publication date
FR653827A (en) 1929-03-28

Similar Documents

Publication Publication Date Title
US1697451A (en) Light-sensitive electric device
US2629757A (en) Method of construction of sensitive thermopiles
JP6442068B2 (en) Sensing device
GB1262435A (en) Pyroelectric detector array
US2711511A (en) Electrical hygrometer
US3693011A (en) Ion implanted bolometer
US2877284A (en) Photovoltaic apparatus
US3075386A (en) Radiation detectors
US2556991A (en) Light-sensitive electric device
US3602721A (en) Photoelectric device with enhanced photoconductive sensitivity and storage effect of input radiation
US3054917A (en) Heat imaging device
US2999941A (en) Solid-state image intensifier
US4469943A (en) Pyroelectric detector
GB587996A (en) An improved means for measuring flow of heat
US3221508A (en) Flexible cold side for thermoelectric module
US2999177A (en) Infra-red-sensitive mosaic
US3354309A (en) Infrared detecting device of the thermopile type
US3143655A (en) Photosensitive switching device in a waveguide
US1714578A (en) Electric heating apparatus
US2953621A (en) Photovoltaic apparatus
USRE22052E (en) Light-sensitive device
US3568010A (en) Thin film capacitive bolometer and temperature sensor
US1375474A (en) Photo-electric apparatus
US3011019A (en) Flying spot camera tube
JPS5899647A (en) Solar heat collector with solar cell