US3874792A - Lamp housing for use in photographic enlargers or the like - Google Patents
Lamp housing for use in photographic enlargers or the like Download PDFInfo
- Publication number
- US3874792A US3874792A US384398A US38439873A US3874792A US 3874792 A US3874792 A US 3874792A US 384398 A US384398 A US 384398A US 38439873 A US38439873 A US 38439873A US 3874792 A US3874792 A US 3874792A
- Authority
- US
- United States
- Prior art keywords
- light
- duct
- walls
- confining device
- plane
- 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
Links
- 241000283986 Lepus Species 0.000 description 12
- 239000000463 material Substances 0.000 description 5
- 238000010276 construction Methods 0.000 description 2
- 241000234435 Lilium Species 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Images
Classifications
-
- 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
- G03B27/00—Photographic printing apparatus
- G03B27/32—Projection printing apparatus, e.g. enlarger, copying camera
- G03B27/52—Details
- G03B27/54—Lamp housings; Illuminating means
- G03B27/545—Lamp housings; Illuminating means for enlargers
Definitions
- ABSTRACT A convertible light confining device for use in lamp housings of photographic projection printers resembles a hollow truncated pyramid through which the light passes in a direction from the top plane toward the base plate or vice versa,
- the sides of the truncated pyramid have rectangular or trapezoidal central portions which are pivotable inwardly about axes located in the top plane to form a second light duct of constant cross-sectional area or a second light duct which resembles a hollow truncated pyramid having a base plane coinciding with the top plane of the first truncated pyramid and a top plane which is smaller than but coplanar with the base plate of the first pyramid.
- the present invention relates to light confining devices in general. and more particularly to improvements in light ducts or light pipes which can he used in lamp housings of photographic projection printers or the like.
- a versatile enlarger should be capable of making enlargements of different sizes. ie. to make larger or smaller prints from a negative.
- the light is not utilized with a satisfactory degree of economy. This is due to the fact that. in such enlargers. only the area of the largest negative is illuminated uniformly and with a maximum degree of efficiency; however. if an enlargement is to be made from a smaller negative. the superfluous illuminated area is covered with opaque masks which results in considerable losses of light energy and prolongs (relatively speaking) the projection time.
- An object of the invention is to provide a photographic projection printer with a novel and improved light confining device which can be used in the lamp housing as a light duct and can be converted to properly illuminate larger or smaller areas of photosensitive material with minimal losses in time and without necessitating even partial dismantling of the lamp housing.
- Another object of the invention is to provide a convertible light confining device which can be used for making enlargements from originals of different sizes and is sufficiently simple to be entrustahle to semiskilled or unskilled persons.
- a further object of the invention is to provide a convertible light confining device which can be installed in existing projection printers as a superior substitute for presently employed sets of light ducts.
- An additional object of the invention is to provide a convertible light confining device which does not occupy more space than a conventional light duct.
- the invention is embodied in a lamp housing for use in photographic projection printers or the like. and more particularly in a light confining and guiding device which forms part of the lamp housing and comprises a plurality of walls movable between first and second positions.
- the light confining device constitutes a first light duct in the form of a hollow truncated pyramid with spaced apart top and base planes and sides which confine light that enters the first duct by passing across one of the planes and issues from the first duct by passing across the other plane.
- the light confining device eonstitutes a second light duct which may form a second hollow truncated pyramid or a hollow shaft of constant or nearly constant cross section from end to end.
- the walls constitute the central portions of the sides ofthe first light duct and are pivotable about a ⁇ e located in the top plane of the first duct.
- One of the light ducts is preferably located within the confines of the other light duct.
- FIG. I is a fragmentary schematic elevational view of a photographic projection printer having a lamp hous' ing with a light duct which embodies the invention:
- FIG. 2 is a diagrammatic perspective view of a light duct which is constructed and assembled in accordance with a first embodiment of the invention
- FIG 3 is a perspective view of a modified light duct
- FIG. 4 is a fragmentary vertical sectional view of the light duct shown in FIG. 3'.
- FIG. 5 is a fragmentary vertical sectional view of the light duct shown in FIG. 2.
- FIG. I there is shown a portion of a photographic projection color printer which is used as an enlarger and embodies a lamp housing including the improved convertible light confining and guiding device.
- the light issuing from a source I is reflected by a reflector 2 so that it passes through a light confining device 4.
- the top part of the device 4 is adjacent to a unit 3 which includes a diffusing screen. means for changing the color of light and a shutter.
- the lower end of the device 4 is adjacent to a further diffusing screen 5.
- the parts 2-5 together constitute a lamp housing for the light source I.
- the light issuing from the device 4 and passing through the diffusing screen 5 thereupon passes through an original 6 and is focussed by an objective lens system 7 so that a portion 6a ofthe original is imaged onto a section 811 of photosensitive print material 8.
- the lens system 7 preferably includes a lens of variable focal length.
- the just described enlarger is of conventional design and is of the type which is used extensively for automatic making of prints from originals. cg. from sticcessivc frames of an exposed and developed photographic roll film.
- Enlargers employing light ducts in place of conventional eondensor lenses are preferred for the making of color prints because the light duct serves as a means for mixing the colors of printing light in accordance with the setting of the color changing means (such as filters) forming part of the unit 3.
- the means for transporting the originals 6 and the photosensitive material 8. the control means for the unit 3 and other conventional parts of the enlarger are not shown in FIG. I.
- the light confining device 4 comprises a light duct in the form of a hollow truncated pyramid which. in the emhodiment of HG. 2. is a regular quadrangular truncated pyramid with a hase plane 42. a top plane 40 which is assumed to he parallel to the hase plane 42. and four trape/oidal sides. I he light en ters h passing across the top plane 40 and issues hy passing across the hase plane 42 which latter is o ⁇ crlapped hy the diffusing screen 5.
- each ofthe four trapc/oidal sides comprises a pi ⁇ otahle trape/oidal central portion or wall 4
- the central portions or walls "IH llf are pivoted from register with the respective corner portions. They constitute a second light duet in the form of a second hollow truncated pyramid having a hase plane coinciding with the top plane 40 of the light duct with the hase plane 42 and four sides t-Ha-4Idl.
- the top plane 4] of the smaller second truncated pyramid is coplanar with or adjacent to the hasc plane 42.
- the edge portions 40a. 40b. 40v. 401/ define pi ⁇ ot a ⁇ es which are located in the plane 40 and ahout which the walls 4lu 4lrl are pivotahle from alignment with the respectne corner portions to the positions shown hy solid lilies in which they constitute the sides ofthc smaller truncated pyramid.
- FIGS. 3 and 4 The details of means for moving slightly modified central portions or walls 4lu' 4lrf' hetween the solidline second positions and the first positions of alignment with the respective corner portions 42u42u'. 42IP4Z/i'. 421 120. 4211-4211" are illustrated in FIGS. 3 and 4.
- the walls -Hu'4ltl' are rectangular so that they may constitute a parallelpiped second light duct with a base plane 40' which is of the same she as the top plane 4!.
- the walls 4lu'4ld' are respectively hiased hy helical springs 43a. 43b. 43.
- Each helical spring is attached to that part of the respective wall which is remote from the corresponding edge portion 40a, 40b. 40:. 4th! and the springs are further secured to fixed retainers 44a. 44b, 44; 44:! on the rigid frame of the enlarger.
- the frame is further rigid with the corner portions 42u-421l'.
- the walls 41a. 4H). 41". 41d are further provided with arcuatc followers 45a. 45/ 451'.
- the wall 4k" is substantially vertical when it forms one side of the smaller light duct and makes an oblique angle with the hasc plane 42' when it forms part of one side ofthe larger duct.
- the larger duct must he provided with additional portions or sills 4811. 48/).
- 48c. 48d which are respectively aligned with and are adjacent to the lower edges of the walls 4lu' 4ld' when the walls form part of the larger duct.
- Such sills are desirahle whenever the angle heta hetween the hase plane 42' aitd a wall 4hr. 4H1. 4h" or 4k!
- the length of a side of the smaller duct should not exceed the length of a side of the larger duct hecause. otherwise. sills must he provided in the larger duct to he aligned with the pivotahle walls in the inner end positions of the walls. Such sills would interfere with the travel of light through the larger duct. Therefore. the angle alpha is smaller than or at most equals the angle heta, i.c.. the inclination ofthe sides of the smaller duct relative to the hase plane of the larger duct should not exceed the inclination of the sides of the larger duct.
- the light confining devices are normally longer than those shown in FIGS. 2 and 3.
- the ratio ofthe maximum transverse dimensions to the height or length of a light confining device depends on the characteristics of the light source I. on the characteristics of the reflector means 2. and/or on the type of the unit 3.
- the inner sides of the ducts are coated with light reflecting material.
- the improved convertible light confining device can he used in automatic copying apparatus as well as in many other optical apparatus. such as projectors. viewers or light hoses serving to illuminate differently di mensioned slides. frames or motion picture film or the like. This renders it possihle to operate a projector without necessitating a replacement oi interchange of condensor lenses.
- the hasc and top planes of the smaller and larger ducts need not he rectangles or squares.
- the im proved light confining device may have any desired polygonal crosssectional outline.
- a light confining and guiding device comprising a plurality of walls movahlc hetween first positions in which said device constitutes a first light duct in the form of a first hollow truncated pyramid with spaced apart top and base planes and contiguous sides which confine light that enters said first duct by passing across one of said planes and issues from said first duct by passing across the other of said planes.
- a light confining device as defined in claim 1. wherein the length of said first light duct. as considered in the direction of the passage of light therethrough. is identical with the length of said second light duct.
- each side of said first light duct further contprises eorner portions flanking the respective all in the first position of such wall.
- a light confining device as defined in claim 9. further comprising a frame which is rigid with said corner portions.
- a light confining de ⁇ ice as defined in claim I. further comprising means for simultaneoush moving said walls between said first and second positions.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Light Sources And Details Of Projection-Printing Devices (AREA)
- Non-Portable Lighting Devices Or Systems Thereof (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2238944A DE2238944C3 (de) | 1972-08-08 | 1972-08-08 | Beleuchtungsvorrichtung in einem Kopiergerät |
Publications (1)
Publication Number | Publication Date |
---|---|
US3874792A true US3874792A (en) | 1975-04-01 |
Family
ID=5852986
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US384398A Expired - Lifetime US3874792A (en) | 1972-08-08 | 1973-08-01 | Lamp housing for use in photographic enlargers or the like |
Country Status (4)
Country | Link |
---|---|
US (1) | US3874792A (de) |
CH (1) | CH560406A5 (de) |
DE (1) | DE2238944C3 (de) |
IT (1) | IT995162B (de) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4009383A (en) * | 1974-10-31 | 1977-02-22 | Agfa-Gevaert A.G. | Light chute arrangement |
US4077716A (en) * | 1975-09-22 | 1978-03-07 | Durst Ag. Fabrik Fototechnischer | Illuminating equipment for a photographic enlarging or copying apparatus |
US4136948A (en) * | 1976-09-09 | 1979-01-30 | Rollei-Werke Franke & Heidecke | Photographic enlarger |
US4194834A (en) * | 1975-12-02 | 1980-03-25 | Zelacolor Systems Establishment | Unit for reproducing transparent originals, or the like |
US4255045A (en) * | 1979-03-28 | 1981-03-10 | Ciba-Geigy Ag | Removable light box |
US4493551A (en) * | 1983-03-24 | 1985-01-15 | Fine Richard A | Illumination means for 3-D printing apparatus |
US5045877A (en) * | 1990-02-21 | 1991-09-03 | Orren J. Lucht | Photographic printer |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4592649A (en) * | 1984-04-04 | 1986-06-03 | Agfa-Gevaert Ag | Photographic roller copying apparatus |
US4949120A (en) * | 1988-04-21 | 1990-08-14 | Ricoh Company, Ltd. | Illuminating device |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1088030A (en) * | 1912-12-26 | 1914-02-24 | Charles Carley Leeds | Enlarging attachment for cameras. |
US1184613A (en) * | 1916-01-05 | 1916-05-23 | James L Boyd | Light-reflector for engine-cabs. |
US3161107A (en) * | 1960-09-20 | 1964-12-15 | Durst S P A Fabrica Macchine E | Illuminating system for photographic enlarger |
US3669538A (en) * | 1970-08-31 | 1972-06-13 | Ibm | Illumination system |
US3684371A (en) * | 1970-11-06 | 1972-08-15 | Berkey Photo Inc | Light head with interchangeable mixing chambers for high speed enlarger |
US3831021A (en) * | 1972-06-09 | 1974-08-20 | Durst Ag | Illuminating device, particularly for photographic enlarging apparatus |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2014789A1 (de) * | 1969-12-24 | 1971-07-01 | Durst Ag, Fabrik Fototechnischer Apparate, Bozen (Italien) | Kopiereinnchtung, insbesondere für fotografische Zwecke |
-
1972
- 1972-08-08 DE DE2238944A patent/DE2238944C3/de not_active Expired
-
1973
- 1973-08-01 US US384398A patent/US3874792A/en not_active Expired - Lifetime
- 1973-08-03 CH CH1127773A patent/CH560406A5/xx not_active IP Right Cessation
- 1973-08-07 IT IT27636/73A patent/IT995162B/it active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1088030A (en) * | 1912-12-26 | 1914-02-24 | Charles Carley Leeds | Enlarging attachment for cameras. |
US1184613A (en) * | 1916-01-05 | 1916-05-23 | James L Boyd | Light-reflector for engine-cabs. |
US3161107A (en) * | 1960-09-20 | 1964-12-15 | Durst S P A Fabrica Macchine E | Illuminating system for photographic enlarger |
US3669538A (en) * | 1970-08-31 | 1972-06-13 | Ibm | Illumination system |
US3684371A (en) * | 1970-11-06 | 1972-08-15 | Berkey Photo Inc | Light head with interchangeable mixing chambers for high speed enlarger |
US3831021A (en) * | 1972-06-09 | 1974-08-20 | Durst Ag | Illuminating device, particularly for photographic enlarging apparatus |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4009383A (en) * | 1974-10-31 | 1977-02-22 | Agfa-Gevaert A.G. | Light chute arrangement |
US4077716A (en) * | 1975-09-22 | 1978-03-07 | Durst Ag. Fabrik Fototechnischer | Illuminating equipment for a photographic enlarging or copying apparatus |
US4194834A (en) * | 1975-12-02 | 1980-03-25 | Zelacolor Systems Establishment | Unit for reproducing transparent originals, or the like |
US4136948A (en) * | 1976-09-09 | 1979-01-30 | Rollei-Werke Franke & Heidecke | Photographic enlarger |
US4255045A (en) * | 1979-03-28 | 1981-03-10 | Ciba-Geigy Ag | Removable light box |
US4493551A (en) * | 1983-03-24 | 1985-01-15 | Fine Richard A | Illumination means for 3-D printing apparatus |
US5045877A (en) * | 1990-02-21 | 1991-09-03 | Orren J. Lucht | Photographic printer |
Also Published As
Publication number | Publication date |
---|---|
DE2238944C3 (de) | 1981-10-29 |
CH560406A5 (de) | 1975-03-27 |
DE2238944B2 (de) | 1980-10-30 |
IT995162B (it) | 1975-11-10 |
DE2238944A1 (de) | 1974-02-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2940358A (en) | Image reversing optical system | |
US3684371A (en) | Light head with interchangeable mixing chambers for high speed enlarger | |
US3874792A (en) | Lamp housing for use in photographic enlargers or the like | |
US3584952A (en) | Lens strip optical scanning system | |
US3099195A (en) | Camera with lenticulated mask | |
US3312143A (en) | Photographic method and system | |
US2086182A (en) | Method of and apparatus fob pro | |
US3506344A (en) | Optical projection system | |
US3558225A (en) | Optical photo opposing apparatus | |
US1808274A (en) | Projection printer | |
US3458254A (en) | Colour printing apparatus | |
US3719419A (en) | Selective single lens projecting system | |
US3224327A (en) | Apparatus for producing uniform exposure across the width of light sensitive sheets | |
JPS62151834A (ja) | 写真複写装置 | |
US3890043A (en) | Enlarging apparatus for use in a bright room | |
US2480101A (en) | Illuminating system for photographic enlargers | |
JPS6242255B2 (de) | ||
US2147434A (en) | Apparatus for reproducing congruent images of one-shot films | |
CA1162584A (en) | Illumination system for microfilm printer | |
US3160083A (en) | Adapter kit for cameras | |
US4286867A (en) | Light source unit assembly for photographic enlarger | |
US1917408A (en) | Film gate for motion picture apparatus | |
US4914470A (en) | Device to be particularly fitted onto color photocopying machines for obtaining reproductions also from diapositives | |
US2518727A (en) | Transparency-positioning device for photographic apparatus | |
US4712911A (en) | Exposure mask for micro camera |