US3488543A - Projection lamp with elliptical mirror and light source mounting structure - Google Patents

Projection lamp with elliptical mirror and light source mounting structure Download PDF

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Publication number
US3488543A
US3488543A US700479A US3488543DA US3488543A US 3488543 A US3488543 A US 3488543A US 700479 A US700479 A US 700479A US 3488543D A US3488543D A US 3488543DA US 3488543 A US3488543 A US 3488543A
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United States
Prior art keywords
mirror
combination
lamp
filament
light source
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
US700479A
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English (en)
Inventor
Jan De Ridder
Thomas Antonius Corneli Jacobs
Cornelis Prijn
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US Philips Corp
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US Philips Corp
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Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K7/00—Lamps for purposes other than general lighting
    • H01K7/02—Lamps for purposes other than general lighting for producing a narrow beam of light; for approximating a point-like source of light, e.g. for searchlight, for cinematographic projector
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/20—Lamp housings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K1/00—Details
    • H01K1/02—Incandescent bodies
    • H01K1/14—Incandescent bodies characterised by the shape

Definitions

  • a halogen projection lamp having an elliptical condensing mirror on the bulbs inner surface, and a helically wound filament having a length-to-diameter ratio less than 1.5 disposed at a focus point of the mirror, with the axes of the filament and mirror coincident.
  • the invention relates to a combination 'of a condenser mirror and a light source for the illumination of the film gate of a film projector, the reflective surface of this condenser mirror having the form of part of an ellipsoid of revolution and the light source having the form of a helically wound filament which contains one of the two foci of this ellipsoid and the axis of which substantially coincides with the axis of revolution of the mirror.
  • Such a combination is known in the form of a projection lamp, a mirror'coated bulb part of which serves as condenser mirror.
  • the bulb of this lamp is closed by a lamp cap in which the current-supply wires of the filament are incorporated in a usual manner.
  • the cap is located at the top of the ellipsoidal mirror, that is to say at the point at which the axis of revolution of the mirror intersects the same.
  • Such a lamp has the advantage that an accurate orientation of the light source with respect to the mirror is obtained already during the manufacture of the lamp and is therefore independent of the manufacturing tolerances in the construction of a projector in which the lamp is to be used.
  • the orientation of the filament along the axis of revolution of the mirror results in that a large part of the light flux emitted by the light source can be collected by the mirror. With differently orientated filaments, the part of the light flux collected by the mirror will generally be smaller. This is also due to the fact that with this orientation, the comparatively dark terminal apertures of the filaments face the lamp cap and the mirror opening, respectively.
  • the known incandescent lamp described has the disadvantage, however, that it is difiicult or impossible to use a halogen incandescent lamp.
  • a halogen incandescent lamp Under suitable operating conditions of an incandescent lamp, the addition of a halogen to the bulb filling of this lamp results in a chemical conversion cycle regenerating the filament so that the life and the light output of the lamp are considerably improved due to the size of the bulb required for normal projection applications where the bulb serves as a mirror.
  • this combination is characterized in that the rotationsymmetrically wound filament is disposed inside the bulb of a halogen incandescent lamp which is firmly secured to the condenser mirror, the ratio between the length and maximum diameter of the 'helically wound part of the filament being smaller than 1.5.
  • a combination can be manufactured which includes a mirror having a size suitable for film-projection applications (for example, a mirror having a maximum diameter of the order of 5 cm.), the high light output of a halogen incandescent lamp being utilized and a high-quality light distribution (over a film gate or projection cloth illuminated by this combination) being obtained.
  • the unfavourable influence of the unevennesses of the lamp bulb can be considerably suppressed by the steps according to the invention when the lamp and the mirror are relativel accurately orientated.
  • the combination is found to have a high light output per unit of supplied power.
  • the dimensions of the filament of the combination according to the invention used in such a projector can be chosen so that the aperture of the objective of this projector is substantially filled by the light beam to be emitted by this combination through the film gate of the projector. Consequently, the objective is fully utilized.
  • the filament may be wound from covered wire.
  • the accurate relative orientation of the light source and the mirror during the manufacture of a combination according to the invention may be obtained in an ei'ficacious manner, for example, by means of an apparatus by which the light distribution brought about on a screen by the combination through a film gate and an objective is measured.
  • the image surface on the screen and the film gate may have the usual rectangular shape. It is found in general that with an optimum orientation of the light source and the mirror of a given combination, the light distribution over such a rectangular image surface depends also on the angular position about the optical axis of the measuring device occupied by this combination during the measurement.
  • the condenser mirror 7 is provided with an annular fitting rim which extends transversely of its axis of revolution and is used for centering the combination with respect to the optical axis passing through the film gate of the projector, so that the angular position of the combination about this optical axis which is the optimum for the light distribution can be fixed in a simple manner.
  • this embodiment is characterized in that the mirror is provided at or in the proximity of its fitting rim with a mark, preferably in the form of an abutment cam or groove.
  • a cam or groove should co-operate with an associated groove or cam of said projector.
  • FIGURE 1 is an elevation of this combination, the mirror being shown in a longitudinal sectional view.
  • FIGURE 2 is an elevation similar to that of FIG- URE 1, but viewed in a direction which is shifted by 90 with respect to the direction of view of FIGURE 1.
  • the mirror is shown in a longitudinal sectional view taken on the line XX of FIGURE 1.
  • FIGURE 3 is a front elevation and FIGURE 4 is a rear elevation of the combination.
  • the embodiment shown comprises a concave condenser mirror body 1 (in this case made of glass) which has on the inner side an ellipsoidal surface which is provided with a thin reflective layer 2.
  • This reflective layer 2 preferably acts as a so-called cold-light mirror.
  • the axis of the ellipsoid of revolution (at the same time the optical axis of the combination) is denoted by XX and one of the two foci by F.
  • the maximum diameter D of the mirror will be of the order of 5 cm.
  • the filament 9 of the halogen lamp 3 is helically wound, preferably from covered wire, and in this embodiment has a cylindrical shape.
  • the filament 9 is suspended in the bulb 4 of the halogen lamp 3 by means of the stay wires 8 which are secured to the foils 6 received by the pinch 5 of the lamp. Furthermore, the current-supply pins 7 are connected to the foils 6.
  • the bulb 4 also has the sealing tip 10. After being accurately orientated with respect to the mirror, the lamp is permanently secured in the neck 14 of the mirror body 1 by means of a suitable cement material 11.
  • the helically wound part of the filament 9 has a length l and a maximum diameter d.
  • the ratio between I and d is smaller than 1.5. Also due to this fact, the advantages mentioned in the preamble with respect to the light output and the uniform light distribution over an image surface illuminated by the combination can be obtained in the combination according to the invention.
  • the mirror body 1 is further provided with an annular fitting rim 12 which, when the combination is secured in a suitable projector, ensures that the combination is satisfactorily centered with respect to the optical axis of the projector.
  • the fitting rim 12 is provided with an abutment cam 13 which indicates the angular position about the optical axis XX in which during manufacture the lamp and the mirror of the combination are relatively orientated so that the combination actually brings about a light distribution of the greatest possible uniformity over an illuminated image field.
  • the abutment cam 13 should co-operate with an associated groove or opening in this projector so that the said optimum angular position of the combination is reproduced with the optimum accuracy.
  • halogen incandescent lamp for use with a film projector to illuminate the film gate thereof, the improvement in combination with the bulb thereof comprising:

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Non-Portable Lighting Devices Or Systems Thereof (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Projection Apparatus (AREA)
US700479A 1967-02-01 1968-01-25 Projection lamp with elliptical mirror and light source mounting structure Expired - Lifetime US3488543A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL6701519.A NL156827B (nl) 1967-02-01 1967-02-01 Projectie-eenheid, bestaande uit een condensorspiegel en een halogeengloeilamp.

Publications (1)

Publication Number Publication Date
US3488543A true US3488543A (en) 1970-01-06

Family

ID=19799186

Family Applications (1)

Application Number Title Priority Date Filing Date
US700479A Expired - Lifetime US3488543A (en) 1967-02-01 1968-01-25 Projection lamp with elliptical mirror and light source mounting structure

Country Status (7)

Country Link
US (1) US3488543A (de)
AT (1) AT272840B (de)
CH (1) CH471398A (de)
DE (1) DE1278233B (de)
FR (1) FR1557948A (de)
GB (1) GB1143914A (de)
NL (1) NL156827B (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3917939A (en) * 1972-07-05 1975-11-04 Bosch Gmbh Robert Sealed-beam headlight employing a halogen lamp
US3936686A (en) * 1973-05-07 1976-02-03 Moore Donald W Reflector lamp cooling and containing assemblies
US3987326A (en) * 1973-05-10 1976-10-19 Robert Bosch G.M.B.H. Sealed-beam headlight
US4081708A (en) * 1975-06-18 1978-03-28 U.S. Philips Corporation Incandescent lamp-reflector unit
US4156271A (en) * 1976-05-05 1979-05-22 General Electric Company Reflector lamp
EP0137200A2 (de) * 1983-08-25 1985-04-17 General Electric Company Lampeneinheit mit Glasreflektorglied mit zurückstehendem Basisende
EP0470496A2 (de) * 1990-08-07 1992-02-12 Toshiba Lighting & Technology Corporation Glühlampe und Projektionslampe vom Reflektortyp
US5178712A (en) * 1989-09-27 1993-01-12 Toshiba Lighting & Technology Corp. Lamp device and method of bonding mirror reflector to lamp

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3700881A (en) * 1971-04-29 1972-10-24 Gen Electric Lamp and reflector assembly
NL179433C (nl) * 1976-06-21 1986-09-01 Philips Nv Elektrische lamp.
HU183426B (en) * 1981-05-08 1984-05-28 Egyesuelt Izzolampa Projecting lamp consisting of incandescent lamp and condensor mirror mounted rigidly to the lamp
JPH06160766A (ja) * 1992-11-25 1994-06-07 Canon Inc 投射型表示装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2233486A (en) * 1939-12-13 1941-03-04 Michael P Portnow Headlight
US3365604A (en) * 1965-12-01 1968-01-23 Sylvania Electric Prod Projection reflector lamp
US3381575A (en) * 1965-12-03 1968-05-07 Sylvania Electric Prod Electric projection lamp
US3390262A (en) * 1965-05-24 1968-06-25 Sylvania Electric Prod Multizone high power light reflector

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH238312A (de) * 1943-02-08 1945-07-15 Texis Societe Anonyme Textile Verfahren zur Herstellung künstlicher Gebilde aus Zellulose- oder Zellulosederivat-Xanthogenaten.
DE3417717A1 (de) * 1984-05-12 1985-11-21 HOLTEC Gölz, Sänger & Massierer GmbH & Co KG, 5374 Hellenthal Vorrichtung zur vermessung von rundholz

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2233486A (en) * 1939-12-13 1941-03-04 Michael P Portnow Headlight
US3390262A (en) * 1965-05-24 1968-06-25 Sylvania Electric Prod Multizone high power light reflector
US3365604A (en) * 1965-12-01 1968-01-23 Sylvania Electric Prod Projection reflector lamp
US3381575A (en) * 1965-12-03 1968-05-07 Sylvania Electric Prod Electric projection lamp

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3917939A (en) * 1972-07-05 1975-11-04 Bosch Gmbh Robert Sealed-beam headlight employing a halogen lamp
US3936686A (en) * 1973-05-07 1976-02-03 Moore Donald W Reflector lamp cooling and containing assemblies
US3987326A (en) * 1973-05-10 1976-10-19 Robert Bosch G.M.B.H. Sealed-beam headlight
US4081708A (en) * 1975-06-18 1978-03-28 U.S. Philips Corporation Incandescent lamp-reflector unit
US4156271A (en) * 1976-05-05 1979-05-22 General Electric Company Reflector lamp
EP0137200A2 (de) * 1983-08-25 1985-04-17 General Electric Company Lampeneinheit mit Glasreflektorglied mit zurückstehendem Basisende
EP0137200A3 (en) * 1983-08-25 1986-01-02 General Electric Company Lamp unit having glass reflector member with recessed base end
US5178712A (en) * 1989-09-27 1993-01-12 Toshiba Lighting & Technology Corp. Lamp device and method of bonding mirror reflector to lamp
EP0470496A2 (de) * 1990-08-07 1992-02-12 Toshiba Lighting & Technology Corporation Glühlampe und Projektionslampe vom Reflektortyp
EP0470496A3 (en) * 1990-08-07 1992-08-26 Toshiba Lighting & Technology Corporation Incandescent lamp and reflector type projection lamp

Also Published As

Publication number Publication date
GB1143914A (en) 1969-02-26
NL156827B (nl) 1978-05-16
FR1557948A (de) 1969-02-21
DE1278233B (de) 1968-09-19
NL6701519A (de) 1968-08-02
CH471398A (de) 1969-04-15
AT272840B (de) 1969-07-25

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