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US2163749A - Radial scanning television system - Google Patents

Radial scanning television system Download PDF

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Publication number
US2163749A
US2163749A US70061A US7006136A US2163749A US 2163749 A US2163749 A US 2163749A US 70061 A US70061 A US 70061A US 7006136 A US7006136 A US 7006136A US 2163749 A US2163749 A US 2163749A
Authority
US
United States
Prior art keywords
vibrating
radial
coils
frequency
television system
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
US70061A
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English (en)
Inventor
Forest Lee De
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.)
AMERICAN TELEVISION LAB Inc
AMERICAN TELEVISION LABORATORIES Inc
Original Assignee
AMERICAN TELEVISION LAB Inc
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 AMERICAN TELEVISION LAB Inc filed Critical AMERICAN TELEVISION LAB Inc
Priority to US70061A priority Critical patent/US2163749A/en
Priority to GB8008/37A priority patent/GB492302A/en
Priority to FR819426D priority patent/FR819426A/fr
Application granted granted Critical
Publication of US2163749A publication Critical patent/US2163749A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
    • H04N3/02—Scanning details of television systems; Combination thereof with generation of supply voltages by optical-mechanical means only
    • H04N3/08—Scanning details of television systems; Combination thereof with generation of supply voltages by optical-mechanical means only having a moving reflector

Definitions

  • This invention relates to a television system in which a single vibrating mirror may be used to scan both dimensions of the transmitted or reproduced image.
  • it relates f.- to the use of such a single vibrating mirror system in such manner as to provide stereoscopic television images, that is images which have the visual effect of a third dimension or depth.
  • An essential feature of both aspects of my invention I is the use of a vibrating mirror which is rotated at the same time that it is vibrating, causing it to scan the image on the reproducing screen in radial lines. I have therefore called my new invention a radial scanning television system, in
  • An object of my invention is to provide a television system which will be economical and efficient in construction and operation and which will give increased detail and greater illumination at the center of the viewing screen, and which may produce stereoscopic images.
  • a feature of my invention is the provision of a mirror mounted on a torsional vibrating member having a fixed resonant frequency, providing means to excite the vibrating system at its resonant frequency, and mounting the entire mirror,
  • vibrating system and exciting means for rotation at a constant frequency bearing a fixed relationship to the picture frequency of the system and to the resonant frequency of the vibrating member.
  • Another feature of my invention is the provision of means cooperating with the rotating means just discussed to produce an exciting frequency equal to the resonant frequency of the torsional vibrating element.
  • Another feature of my invention is the provision of means for causing the radial scanning device to scan an area of rectangular shape, or any other desired shape.
  • Another feature of my invention is the provision of a double radial scanning transmitter and double radial scanning receiver of television signals to produce a stereoscopic effect.
  • Figure 1 is a side elevation of a radial scanner in accordance with the present invention.
  • Figure 2 is a front view of the device of Figure 1, looking from the right in that figure;
  • Figure 3 is a diagrammatic view of means for causing the rotating element of my radial scanner to produce an electric current of a frequency equal to the resonant frequency of the vibrating element and to supply this current to coils which excite the vibrating element;
  • Figure 4 is a diagrammatic View illustrating the manner in which my radial scanner will scan 5 an image
  • Figure 5 is a diagrammatic view of means for causing my radial scanner to scan a rectangular area
  • Figure 6 is a curve illustrating the envelope of 10 the grid potentials on the amplifier 5
  • Figure 7 is a plan view of an alternative shape for my distorting condenser of Figure 5;
  • Figure 8 is a plan View of another alternative 15 shape for my distorting condenser of Figure 5;
  • Figure 9 is a schematic diagram of the transmitter of a radial scanning television system designed to produce stereoscopic images
  • Figure 10 is a schematic diagram of a receiver 20 in my radial scanning television system for reproducing stereoscopic images
  • Figure 11 is a diagrammatic View illustrating a viewing screen and the manner in which the images produced by the apparatus of Figure 10 25 are projected on such a screen;
  • Figure 12 is a diagrammatic view of another manner of projecting images and using a double radial scanning system such as illustrated in Figures 9 and 10. 30
  • FIGS 1 and 2 I show a synchronous motor 21 which may be operated from a power network.
  • a disc 23 Keyed to the shaft 22 of the motor is a disc 23 which may be of non-magnetic material. Carried on the disc 23 for rotation therewith is a 35 magnetic system consisting of a magnetic core 24 having four pole pieces 25, 26, 21 and 28 which are surrounded respectively by coils 29, 30, 3
  • may be caused to rotate at any 5 desired frequency, say, for example, twenty-five revolutions per second. As it rotates it carries with it the disc 23 and the entire vibrating and magnetic system mounted on that disc, including all the elements numbered from 24 to 31, inclu- 55 sive. Slip rings (not shown) are provided in order to supply direct current to the coils 29 and 3!. Additional slip rings (also not shown) are provided in order to supply an alternating current to the coils 30 and 32 of a frequency equal to the resonant frequency of the torsional vibrating member 35.
  • the apparatus of Figures 1 and 2 is to be used at both the transmitting and receiving ends of a television system and of course to cooperate with suitable light sources, optical systems, viewing screens, etc., such as are illustrated in connection with Figures 9 and 10.
  • a source of light, optical system, photoelectric cell, amplifier, modulator, and wire or radio transmitting system would be used similar to the corresponding elements numbered and marked 68, 69, 13, Amp, Radio transmitter, 15, in Figure 9.
  • One-half cycle later that is of a second later, it will scan another line corresponding to the line 39 of Figure 4, etc., until in of a second the motor has completed a revolution and one frame of the image will be scanned.
  • the image will appear to be circular and it may be viewed on a circular screen or it may be masked out by placing a black non-reflecting mask over the screen, such as illustrated by the cross-hatched area 20 of Figure 12.
  • Figure 3 I have illustrated one method of producing a current of a frequency corresponding to the resonant frequency of the vibrating system 35 without the use of slip rings, and in which the necessity for transmitting synchronizing impulses is eliminated provided the synchronous motors at the transmitting and receiving station are driven from the same power network.
  • the disc 23 which in this case will be of magnetic material, has mounted on its periphery a plurality of poles 4% carrying coils 45. The disc, as before, has mounted on it the coils 3i? and 32 around the poles 26 and 28 to which the current of the resonant frequency of the vibrating system is to be supplied.
  • the disc 23 also has the torsional vibrating member 35 mounted thereon which again carries the crosspiece 36 and mirror 37.
  • stator 45 On which are mounted a plurality of pole pieces 31 carrying stator coils 48 which are excited by a direct current.
  • a current of the resonant frequency of the vibrating member 35, or a sub-multiple thereof, is excited in the windings Q5 and is supplied direct to the windings 30 and 32.
  • stator poles may be made of permanent magnets, avoiding the necessity of using windings or a source of direct current, and inasmuch as the mirror vibrating coils may be excited at a sub-multiple of the resonant frequency the stator poles may be few in number and therefore made relatively large.
  • the armature 52 of a rotating condenser whose stator 53 of square shape is mounted so that the armature 52 rotates within the frame of the stator.
  • This condenser 52, 53 has for convenience been shown separated from the motor 2
  • a brush 54 makes contact with the rotor of this condenser.
  • the leads from the condenser 55 and 56 are connected to the grid-filament circuit of an oscillator 51 which may be of any conventional type, such as a triode as shown.
  • the plate circuit of the oscillator is made oscillating by means of the variable condenser 58 connected across the lower portion of the coil 56.
  • is connected in the plate circuit of the oscillator 51.
  • a periodic change in the capacity of the oscillating grid circuit of the oscillator 51 occurs. This periodic change approximates in magnitude the geometric relationship between the square armature 53 and the motion of the rotating armature 52.
  • This periodic change of capacity produces a corresponding change in the amplitude of the oscillations generated by the triode 51, which in turn is represented by a corresponding change in current in the plate circuit of this triode and consequently by a corresponding change in potential across the resistance 66.
  • the resistance 66 is connected across the grid and filament of the amplifier 5! so that the grid of this amplifier is biased in proportion to the variations in potential across this resistance, and therefore in proportion to the capacity of the condenser 52, 53.
  • a grid biasing battery 62 may be used to provide a desired initial bias of the amplifier 5
  • is thus modulated in accordance with the shape and motion of the condenser 52, 53 and consequently in accordance with the shape of the image to be projected on the screen.
  • is supplied by means of a pair of brushes 63, 64 to the coils 30 and 32 through the slip rings 65 and 66. These brushes 63 and 64 are shown twice in this figure. At the right of the figure they are shown connected to the output circuit of the amplifier 5
  • is supplied back tothe coils 30 and 32 by means of the brushes as shown at the left of the figure.
  • the brushes 63, 64, slip rings 65, 66, coils 30, 32, crosspiece 36, and mirror 31 are shown at the right of the figure for convenience of illustration but actually there are only the single elements of these members as illustrated at the left of the figure where all of them, except, of course, the brushes, rotate with the disc 23.
  • the beam of light is thereby caused to traverse a square area instead of a circular area.
  • the useful illuminated area upon the viewing screen is thus economized and made more intense.
  • FIG 9 I have illustrated my radialscanning television system in use as a transmitter 01 stereoscopic television images.
  • my radial scanners consisting each of a motor 2
  • the object to be scanned is illustrated at 61.
  • I have a source of light 68 which is projected through a suitable optical system indicated at 69 upon the mirror 31 of the upper scanner and reflected in radial scanning lines upon the image 61 which is to be transmitted.
  • I may provide a mask 12 with an opening just large enough to permit the two radial scanning cones of light to pass therethrough.
  • the two radial scanners shown in this figure are turned at an angle pointing to the object 61 and separated laterally to permit the stereoscopic viewing of the object by the two vibrating mirrors 31.
  • the light reflected from the light sources 68 and 10 is picked up respectively by two photoelectric cells 13 and 14 which are connected through suitable amplifiers and radio transmitters to the radiating antennas 15 and 16 respectively. It would, of course, be possible to use a single motor to operate the two radial scanners by suitable gearing and also to use a single radio transmitter and single antenna from which the two radio frequencies would both be radiated,
  • Figure 10 I have illustrated a television receiver for my stereoscopic signals transmitted with the apparatus illustrated in Figure 9.
  • an antenna 11 in which the two frequencies transmitted from the apparatus of Figure 9 are received, a radio frequency amplifier, and two filter systems for separating the two frequencies, Each of these frequencies is supplied to an optical device, such, for example, as Kerr cells 18, 19.
  • an optical device such, for example, as Kerr cells 18, 19.
  • suitable optical systems such as lenses 82, 83 and Nicol prisms 84, 85
  • I may also use my double radial scanning system, as illustrated in Figures 9 and 10, to increase the definition and light on a viewing screen by simply superimposing the images on one another, exhibiting them as a single square as illustrated in Figure 12.
  • I will place my transmitting scanners close together and cause them to scan the same area and also place my receiving scanners close together and cause them to scan the same area.
  • I may cause the lines to be projected in any suitable angular relation to one another, as for example at right angles, so that the lines projected from different scanners will be projected along different lines of the screen at any instant. I may also cause the lines to interlace, thus getting twice the definition at the extremities of the image.
  • I may use the principle of beat frequencies, by employing two sources of high frequency current, both of which are impressed upon the coils of the vibrating magnet; one frequency may be 5000 cycles and the other 4900 cycles or one frequency may be 5050 and the other frequency 4950 cycles.
  • the beat frequency between these two is cycles, which means that if the mirror is rotating at the rate of 25 revolutions per second, then 4 times for each revolution the mirror will be subject to a force of maximum amplitude, corresponding roughly to the corners of the square picture, and 4 times per revolution subject to a minimum impulse, corresponding to the 4 sides of the square of the picture frame.
  • this beat frequency principle the shape of the picture may be made to approximate a square.
  • a radial scanner for a television system comprising a rotating member, a pair of coils mounted on said member, a plurality of teeth mounted on the periphery of said member, a plurality of coils surrounding said teeth, means for exciting an alternating current in said coils surrounding said teeth, and means for supplying said current to said first mentioned coils.
  • a radial scanner for a television system comprising a rotating member, a vibrating member mounted on said rotating member, a pair of coils for exciting said vibrating member into vibration, means mounted on said rotating member for generating a current having a frequency equal to the resonant frequency of said vibrating member, and means for supplying said current to said coils.
  • a television system comprising a rotating member, a vibrating member mounted on said rotating member, means mounted on said rotating member for exciting said vibrating member, means mounted on said rotating member whereby it acts as the rotor of an alternator, a stator for said alternator, and means for supplying the currents produced by said alternator to said exciting means.
  • a radial scanner for a television system comprising a rotating member, a vibrating member mounted on said rotating member, a condenser having a rotor mounted on said rotating member, an oscillator, means for causing said condenser to vary the amplitude of oscillations of said oscillator, a resistance connected in the circuit of said oscillator, means cooperating with said rotating member to generate a current having a frequency equal to the resonant frequency of said vibrating member, an amplifier supplied with said current, electrical connections between said amplifier and the resistance in the circuit of said oscillator whereby said current is modulated in proportion to the variation in potential across said resistance, and means for supplying said modulated current to the means which causes said vibrating member to vibrate.
  • a television system comprising a rotating member, a vibrating member mounted on said rotating member, means for exciting said vibrating member, means mounted on said rotating member whereby said rotating member acts as the rotor of an alternator, a stator for said alternator, means for distorting the electrical currents produced in said alternator, and means for supplying said distorted currents to said exciting means.
  • a television system comprising a rotating member, a vibrating member mounted on said rotating member, means for exciting said vibrating member, a stator, means whereby said rotating member causes electrical currents to be generated in said stator, means for distorting said currents, and means for supplying said distorting currents to said exciting means.
  • a television system comprising a rotating member, a vibrating member mounted on said rotating member, means mounted on said rotating member for exciting the said vibrating member, means for generating electrical current of a frequency equal to the resonant frequency of said Vibrating member, means for amplifying said current, means mounted on said rotating member for modulating the current in said amplifier, and means for supplying said modulated current to said exciting means.
  • a tortional member which moves in one plane, a mirror mounted on said member, and means for moving said tortional member continuously in one direction.
  • a tortional member the axis of which is designed to 5 move in one plane only, a mirror mounted on said member, and means for moving the torti'onal member continuously in one direction.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)
  • Mechanical Optical Scanning Systems (AREA)
US70061A 1936-03-21 1936-03-21 Radial scanning television system Expired - Lifetime US2163749A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US70061A US2163749A (en) 1936-03-21 1936-03-21 Radial scanning television system
GB8008/37A GB492302A (en) 1936-03-21 1937-03-18 Improvements in and relating to television scanning systems
FR819426D FR819426A (fr) 1936-03-21 1937-03-19 Système de télévision à exploration radiale

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US70061A US2163749A (en) 1936-03-21 1936-03-21 Radial scanning television system

Publications (1)

Publication Number Publication Date
US2163749A true US2163749A (en) 1939-06-27

Family

ID=22092878

Family Applications (1)

Application Number Title Priority Date Filing Date
US70061A Expired - Lifetime US2163749A (en) 1936-03-21 1936-03-21 Radial scanning television system

Country Status (3)

Country Link
US (1) US2163749A (fr)
FR (1) FR819426A (fr)
GB (1) GB492302A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2838602A (en) * 1952-06-28 1958-06-10 Ibm Character reader
US3223777A (en) * 1962-11-26 1965-12-14 Jack A Crawford Scanner system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE912368C (de) * 1938-10-08 1954-05-28 Aeg Vorrichtung zur gleichzeitigen Beobachtung von vorzugsweise verschiedenfoermigen Oszillogrammen, die auf vier verschiedenen Bildschirmen aufgezeichnet werden

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2838602A (en) * 1952-06-28 1958-06-10 Ibm Character reader
US3223777A (en) * 1962-11-26 1965-12-14 Jack A Crawford Scanner system

Also Published As

Publication number Publication date
FR819426A (fr) 1937-10-19
GB492302A (en) 1938-09-19

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