US2248559A - Scanning disk for television transmission - Google Patents

Scanning disk for television transmission Download PDF

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Publication number
US2248559A
US2248559A US221318A US22131838A US2248559A US 2248559 A US2248559 A US 2248559A US 221318 A US221318 A US 221318A US 22131838 A US22131838 A US 22131838A US 2248559 A US2248559 A US 2248559A
Authority
US
United States
Prior art keywords
image
disk
line
spiral
lines
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
US221318A
Other languages
English (en)
Inventor
Schlesinger Kurt
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.)
LOEWE RADIO Inc
Original Assignee
LOEWE RADIO 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
Priority to NL50096D priority Critical patent/NL50096C/xx
Priority to BE415945D priority patent/BE415945A/xx
Priority to CH194301D priority patent/CH194301A/de
Priority to CH207046D priority patent/CH207046A/de
Priority to US83705A priority patent/US2227006A/en
Priority claimed from US83705A external-priority patent/US2227006A/en
Priority to GB16091/36A priority patent/GB476181A/en
Priority to FR808318D priority patent/FR808318A/fr
Application filed by LOEWE RADIO Inc filed Critical LOEWE RADIO Inc
Priority to US221318A priority patent/US2248559A/en
Application granted granted Critical
Publication of US2248559A publication Critical patent/US2248559A/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
    • H04N5/00—Details of television systems
    • H04N5/04—Synchronising
    • H04N5/06—Generation of synchronising signals
    • 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
    • H04N3/04—Scanning details of television systems; Combination thereof with generation of supply voltages by optical-mechanical means only having a moving aperture also apertures covered by lenses
    • 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
    • H04N3/36—Scanning of motion picture films, e.g. for telecine
    • 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
    • H04N3/36—Scanning of motion picture films, e.g. for telecine
    • H04N3/38—Scanning of motion picture films, e.g. for telecine with continuously moving film

Definitions

  • the receiving station if upon the reception the relaxation oscillations commences and ends upon each second relaxation period to theextent of'the width of one line higher or lower than the preceding period.
  • the vertical relaxation oscillation must perform in addition .to the normal Scanning movement a rocking movement of the height of a line width, i. e. the so-called line jump.
  • this line jump it was necessary to transmit from the sending end image-change impulses, of which each second one was produced by a line period earlier or later respectively as compared with an exactly isochronous sequence. It was accordingly necessary to transmit the image-change signals in the form of a group each comprising two anisochronous part-impulses.
  • Fig. 5 serves to explain an operation of a spiral disk of several turns
  • Fig. 6 shows an arrangement of producing synchronisation impulses, to which further reference is made in the following paragraphs.
  • each group of lines comprises one and a half lines.
  • the first group of lines comprises the lines in and (12, the second group of lines the lines in and b2.
  • the group of lines I) is disposed in the intermediate spaces of the group of lines a without it being necessary for the vertical Screen apparatus to depart from the two limiting points; 0, the upper edge of the image, and d, the lower edge of the image.
  • An oscillation of this kind between two fixed lines of limitation can be The number of lines is fractional in respect of each part-image.
  • Fig. 2 there is shown a scanning disk suitable for the transmission of 239 full lines.
  • the sectional area on to which the film image is projected is designated 2.
  • the same is formed by two radii 3 and 4, which are taken through the holes I and 239, the two extreme image holes of a two turns spiral.
  • the spiral is an Archimedian spiral running continuously from number I to number 239 without interruption and without irregularities.
  • the angle a between two subsequent radii of a disk of this kind is represented in the case of 2 holes by This angle amounts for example in the case of a disk having 239 holes to 3 45".
  • a transmission with a disk of this kind will be performed with advantage in conjunction with the so-called self-synchronising image point method.
  • each image element must traverse a starting line 5 at the edge of the image on the left hand side. This is accentuated in relation to the image by particularly bright lighting and provides the line synchronisation signal with excess of amplitude.
  • a spiral diaphragm which is designated 6 in Fig. 2 and rotates in the same direction at half the velocity.
  • the disk rotates for example at 6000 R. P. M. and the diaphragm 6 at 3000 R. P. M.
  • the diaphragm may rotate in the plane of an intermediate air image for avoiding loss of light or lack of sharpness.
  • an image-change synchronisation In addition to the line synchronisation, which is effected by the starting line, there is also required an image-change synchronisation. This is obtained by a single synchronisation slot 1.
  • This synchronisation slot cuts a projection 5' of the starting line 5, which may be regulated by means of a shiftable gap, so that the intensity of both synchronizing signals is equal.
  • the image-change slot 1 on each occasion when it passes through the starting line 5', is freed up to the photo-cell.
  • the shading diaphragm 6 is furnished with two openings 8 and 9 which are generously dimensioned in the peripheral direction.
  • the length of the slot 1 determines the duration of darkening of the vertical return line. I It has been found that in the television art a duration of the return amounting to 1% is fully adequate. 1 may accordingly have the length of 1-3 line periods.
  • Fig. 3 there is to be seen in what manner the reproduction of the original film passes over the decomposing points of the disk and both sections move one against the other.
  • the movement of the film image 6 is divided into 7 phases.
  • the image moves evenly from the bottom towards the top and the image holes of the disk move at the same rate but in opposition from the top towards the bottom.
  • the disk contains seven holes and decomposes the film into 2 3.5 lines.
  • phase a there operates the hole 4. Up to the phase I) it has scanned the topmost line I of the reproduction of the film.
  • phase b there commences the hole 5, and up to phase 0 it has scanned the line 3.
  • phase 0 there commences the hole 6 which up to phase d has scanned the line 5.
  • phase (Z the lowermost hole I scans line I of the original. It does not complete this, however, but moves away from the original image at the lower edge after completion of a halfline. At this moment there requires to commence the image-change impulse.
  • the commencement of the image change signal is entered as 1. By reason of the jump in the disk section from the hole 1 to the following hole I there is initiated the scanning of, the second group of lines.
  • the first scanning of a single film image begins when its upper end has reached the middle of the film gate, is made by the inner turn of the spiral and is finished when the image covers the gate; now begins the second scanning which is made by the outer turn of the spiral.
  • the diaphragm 6 runs at 1,500 revs.
  • This shading diaphragm may be arranged either close to the disk, so that it throws a comparatively sharp shadow on the disk, or it may also be arranged in the plane of an air image of the disk.
  • the plane of the disk is designated 23 in Fig. 5.
  • the film 25 is reproduced sharply on this disk by means of a lens 2 3.
  • an auxiliary lens 25' there is again produced from the image on the disk 23 an air image 25 and in this image plane the said diaphragm 6. Behind this there may be connected the photo-cell I I either in direct fashion or with the interposition of a collimator ID.
  • the frame synchronisation is eifected by means of a synchronisation slot 1.
  • the slot 1 must commence with the same central angle either with the hole I or with the middle point
  • the slot is uncovered as many times as partimages are to be disposed one over the other.
  • the slot is uncovered twice upon four revolutions of the main disk.
  • each part-image is scanned to the extent of one-half of a line period too late as compared with the preceding one, and I a starting line, also be effected by means of a light chopper consisting of a row of slots M (Fig. 4:).
  • a slot l4 In order to obtain the line synchronisation frequency a slot l4 must be provided for each radius taken from an image point to the central point,
  • This frequency reduction is produced preferably by electric means.
  • Fig. 6 there is shown an arrangement of this kind.
  • the disk having 4 or 2 spirals and rotating with 6,000 or 3,000 revolutions generates by its apertures M in conjunction with a light source 15, a photo-cell i6 and an amplifier H a control frequency.
  • This is not capable of being employed in direct fashion for synchronisation of the received image.
  • it is .passed to a frequency reducer l8.
  • This frequency reducer i8 may consist of a relaxation generator in which a condenser 49 is charged by a resistance 20 with a frequency of A1 or /2 of the aforesaid slot frequency.
  • an impulse series may accordingly be tapped as sub-harmonic. This may be employed, possibly after filtering, in immediate fashion for synchronisation of the receiver.
  • An advantage of this method is the fact that no rotating screening diaphragm is required.
  • Scanning disk for television transmission for scanning a continuously moved film with interlaced lines rotating at a higher speed than 1) times per image, p being the number of part images, and having a spiral of 2 points equally distributed over the spiral, 2 being the total number of lines of an image, p and 2 having no common factor, and a shutter for uncovering at once one of said turns.
  • Scanning disk for television transmission for scanning a continuously moved film with interlaced lines rotating twice per image, two being the number of part images, and having a spiral of a points equally distributed over the spiral, 2 being the total number of lines of an image, being an odd number, and a shutter for uncovering at once one of said turns.
  • Scanning disk for television transmission for scanning a continuously moved film with interlaced lines rotating p times per image, p being the number of part images, and having a spiral of 2 points equally distributed over the spiral, a being the total number of lines of an image, 12 and 2 having no common factor, and a shutter for uncovering at once one of said turns, said disk being further provided with a special slot for producing one frame change signal per revolution.
  • Scanning disk for television transmission for scanning a continuously moved film With interlaced lines rotating in times per image, 1) being the number of part images, and having a spiral of 2 points equally distributed over the spiral, 2 being the total number of lines of an image, p and 2 having no common factor, a shutter for uncovering at once one of said turns, and means for projecting a small light bundle of great brightness at the margin of the image on. said disk for producing the line change signals when scanned by said holes.
  • Scanning disk for television transmission for scanning a continuously moved film with interlaced lines rotating 10 times per image, 1) being the number of part images, and having a spiral of 2 points equally distributed over the spiral, 2 being the total number of lines of an image, p and 2 having no common factor, said disk being further provided with "a separate rim of 2 slots for producing p impulses per revolution, and a frequency reducer for reducing said 1oz impulses to 2 line synchronizing impulses per image.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Details Of Television Scanning (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)
US221318A 1934-09-29 1938-07-26 Scanning disk for television transmission Expired - Lifetime US2248559A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
NL50096D NL50096C (en(2012)) 1935-06-11
BE415945D BE415945A (en(2012)) 1935-06-11
CH194301D CH194301A (de) 1934-09-29 1935-08-09 Fernsehübertragungsverfahren und Anordnung zur Durchführung desselben.
CH207046D CH207046A (de) 1935-06-11 1936-06-03 Fernsehübertragungsverfahren und Anordnung zur Durchführung desselben.
US83705A US2227006A (en) 1935-06-11 1936-06-05 Scanning device
GB16091/36A GB476181A (en) 1935-06-11 1936-06-09 Scanning disc for television transmitters
FR808318D FR808318A (fr) 1935-06-11 1936-06-09 Disque de décomposition pour émetteurs de télévision
US221318A US2248559A (en) 1935-06-11 1938-07-26 Scanning disk for television transmission

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE207046X 1935-06-11
CH194301T 1936-06-03
US83705A US2227006A (en) 1935-06-11 1936-06-05 Scanning device
US221318A US2248559A (en) 1935-06-11 1938-07-26 Scanning disk for television transmission

Publications (1)

Publication Number Publication Date
US2248559A true US2248559A (en) 1941-07-08

Family

ID=32074436

Family Applications (1)

Application Number Title Priority Date Filing Date
US221318A Expired - Lifetime US2248559A (en) 1934-09-29 1938-07-26 Scanning disk for television transmission

Country Status (6)

Country Link
US (1) US2248559A (en(2012))
BE (1) BE415945A (en(2012))
CH (1) CH207046A (en(2012))
FR (1) FR808318A (en(2012))
GB (1) GB476181A (en(2012))
NL (1) NL50096C (en(2012))

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2525891A (en) * 1947-07-17 1950-10-17 Gen Precision Lab Inc Television recording or transmitting apparatus using constant speed film

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE743667C (de) * 1937-04-12 1943-12-30 Fernseh Gmbh Abtasteinrichtung fuer die Fernsehuebertragung

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2525891A (en) * 1947-07-17 1950-10-17 Gen Precision Lab Inc Television recording or transmitting apparatus using constant speed film

Also Published As

Publication number Publication date
GB476181A (en) 1937-12-03
NL50096C (en(2012))
FR808318A (fr) 1937-02-03
BE415945A (en(2012))
CH207046A (de) 1939-09-15

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