US3652892A - Illuminating lamp having concave segments on exterior bulb surface - Google Patents

Illuminating lamp having concave segments on exterior bulb surface Download PDF

Info

Publication number
US3652892A
US3652892A US873517A US3652892DA US3652892A US 3652892 A US3652892 A US 3652892A US 873517 A US873517 A US 873517A US 3652892D A US3652892D A US 3652892DA US 3652892 A US3652892 A US 3652892A
Authority
US
United States
Prior art keywords
bulb
segment
illuminating lamp
segments
angle
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
US873517A
Other languages
English (en)
Inventor
Naeyoshi Nameda
Tetsuhiro Kano
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.)
Toshiba Corp
Original Assignee
Tokyo Shibaura Electric Co 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
Priority claimed from JP1968097517U external-priority patent/JPS472552Y1/ja
Application filed by Tokyo Shibaura Electric Co Ltd filed Critical Tokyo Shibaura Electric Co Ltd
Application granted granted Critical
Publication of US3652892A publication Critical patent/US3652892A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K1/00—Details
    • H01K1/28—Envelopes; Vessels
    • H01K1/30—Envelopes; Vessels incorporating lenses

Definitions

  • ABSTRACT An illuminating lamp wherein the bulb is fabricated into a complicated fon'n characterized by a large number of surface irregularities so as to disperse light from a luminous source without losing its original brilliance and afford comfortable ornamental illumination by projecting light over a broad area from the various convex and concave segments of the bulb surface utilizing the primary refraction caused by the lenticu- A lar and prismatic action of said segments.
  • FIG.3D F1035 F-l-G.3F
  • PATENTED HAH 2 8 I972 3, 6 52.8 9 2 saw on HF 10 BY W z/fw PATENTEnmze 1972 3,652,892 sum 05 0F 10 INVENTOR.
  • a luminous source lacking a dispersing function for example, a transparent bulb lamp
  • illumination therefrom has an intense glare and dazzles the naked eye, causing discomfort.
  • a process of frosting a bulb or globe covering the luminous source In the case where the lamp member is frosted, light is dispersed after being subjected to complicated refraction, so that the bulb or globe as a whole looks bright, or the luminous source appears to grow large. Since, however, the original brilliance of light decreases, use of a bulb having complicated surface irregularities only results in beauty of form and not beauty of brilliance rendering such type of lamp suitable for ornamental illumination.
  • the present invention uses a novel type of bulb having a complicated shape with surface irregularities in covering a luminous source, disperses the source light only by primary refraction without subjecting it to complicated refraction as is the case with the prior art lamps, and makes an apparent luminous source look large, bright and beautiful without dazzling the naked eye.
  • the present invention is characterized in that a luminous source is covered with a bulb, there are formed in the outer surface of the bulb a large number of convex and concave segments so as to disperse the source light, both end portions of each segment have a plane inclined at an angle of about 8 [8 1 (1r/2 A)] (where 1; represents the angle of incidence of the source light and A denotes the critical angle of said light refracting through the segment) and the area defined between said end portions is formed into a curved or flat plane.
  • the lenticular and prismatic action of the aforesaid numerous convex and concave segments enables the source light to be dispersed over as broad an area as possible simply by primary refraction without causing it to lose its original brilliance.
  • the main object of the present invention is to provide an illuminating lamp free from a dazzling effect and adapted for ornamental illumination wherein the aforesaid lenticular and prismatic action of the segments of the bulb surface affords brilliance as if from numerous dot-like luminous sources.
  • FIGS. 1A to 5C are optical illustrations of the principle underlying the present invention.
  • FIGS. 6A to 6K are perspective views of various modifications of the bulb segments used in the present invention.
  • FIGS. 7A and 7B are the side and bottom views respectively of an illuminating lamp according to an embodiment of the invention.
  • FIGS. 8A to 8C are enlarged views of the main part of said embodiment.
  • FIG. 9 is an elevation, with part broken away, of an illuminating lamp according to another embodiment.
  • FIG. l0' shows the related positions of the filament and segments of the lamp shown in FIG. 9;
  • FIG. 11 is a cross sectional view, with part enlarged, of the bulb used in the lamp of FIG. 9;
  • FIG. 12 is a longitudinal sectional view, with part enlarged, of the bulb used in the lamp of FIG. 9;
  • FIG. 13 is a diagram of the relationship between the ratio of the lengthwise to the crosswise length of each segment and the ratio of the filament length to the bulb radius;
  • FIG. 14 is a diagram of the relationship of the angle of inclination of the prescribed plane of each segment versus the distance between the filament and the inner wall surface of the bulb.
  • the source light is to be dispersed simply by primary refraction, then it is only necessary to form, by customary process, on the outer surface of a bulb covering a luminous source, a plurality of segments capable of performing a lenticular and prismatic action.
  • an illuminating lamp is desired which will display a more advanced effect which fully meets the aforesaid object, then it is necessary that the source light be subjected to refraction and dispersion over a broad area by each segment and that even when the bulb is looked at from a position or angle involved in a broader area than has been possible with the prior art, and the lights are recognized from a larger number of segments, namely, a larger number of segments are made to look bright.
  • angle 1; of incidence and angle 6 of refraction respectively denote angles of inclination with respect to an axis 1 perpendicular to a plane passing point A before inclined as described above, namely, the plane S represented by the outer surface of the glass plate Q. If, in this case, the angle 8 of refraction or the angle of inclination defined by the plane S passing point A with the aforementioned axis 1 is designated as positive when it rotates leftward and as negative when it rotates rightward, then said angle 8 of refraction may be given by the following equation:
  • the degree of inclination of the upper and lower end portions of each segment of the bulb surface is defined in accordance with the above equation (I) and the area between said upper and lower end portions has a flat and/or curved plane, then said segment can disperse the source light over as broad a range as possible in the vertical direction.
  • the angles 0,, and 0 of incidence from the luminous source P to the bulb Q are 3l and 2150 respectively, and the refractive index is 1.47, the angles 1; and 11 of incidence at points a and b are 2030 and 1440 respectively. Accordingly, it is seen from the above equation (1) that it is only required to set the angle 1 of inclination at point a at 6730 when the source light refracts upward and at --2630' in the case of downward refraction, and the angle 17 of inclination at point b at 5740 when the source light refracts upward and at 3620 in the case of downward refraction. In this connection, therefore,
  • FIGS. 3A to 3F there may be contemplated, as shown in FIGS. 3A to 3F, various types of surface segments having straight and/or curved line with the above-mentioned angles of inclination so as to refract lights in opposite directions to each other through tangentially contacting said flat planes covered with fiat and/or curved planes therebetween.
  • numeral 1 represents a transparent cylindrical bulb 5 mm. thick made of soda lime glass.
  • One end of the bulb l is sealed flat to form a bottom section 2 and the other end is sealed to form a conical section 3 open at the end.
  • a stem 5 which supports by means of a conductor 6 a filament 7 presenting a color temperature of 2,700 K. at the time of lighting, for example, with 100 v., 40 w.
  • Said filament 7 is positioned at the center of the bulb 1.
  • the sealed part of the stem 5 is covered with a base cap.
  • the above-mentioned arrangement disperses the light given forth by the filament 7 (a luminous source) over a broad area after it is subjected to primary refraction. Accordingly, larger number of segments formed all over the outer surface of the bulb l are beautifully illuminated, or appear to form luminous sources by themselves, thus affording optimum illumination for ornamental purposes without a dazzling, uncomfortable effect on the naked eye. Moreover, since dispersion can be carried out over a broadest possible area, the image of a filament as a luminous source is concealed from view.
  • the lamp of FIG. 9 is characterized in that where the length l of the filament is relatively larger to the radius L of the bulb, the length (a) of each segment parallel to the lengthwise plane of the filament and its width (b) in a perpendicular direction thereto bear a ratio (a/b) of more than 1.2, and that there are formed segments whose inclined plane defines an angle 0 of more than 30 with the outer surface of the bulb.
  • the bulb 21 is made of, for example, light transmissive material such as glass.
  • the other ends (not shown) of the lead-in wires 23 are extended to be electrically connected to the base cap 25 so as to form terminals.
  • the interior of the bulb 21 is evacuated, filled with inert gas and sealed airtight.
  • On the outer surface of the bulb 21 are formed a plurality of segments 28 having such surface irregularities as illustrated. These irregularities eliminate the dazzling effect of the filament 22 and conceal its shape from view, thus offering a pleasant visual appeal.
  • the same parts of FIG. 10 as those of FIG. 9 are denoted by the same numerals.
  • the length of the filament 22 is designated as l, the
  • the filament has a length of more than about 5 mm. and the ratio l/L is more than l/ 10, and in consequence the ratio all; is more than 1.2 and the angle of inclination defined by the end portion of the segment at the lengthwise portion thereof with the assumed fiat plane of the outer surface of the bulb which would be presented if there were not formed any segments thereon, namely, the angle of inclination 0 is more than 30,then it has been experimentally confirmed that there can be prevented the dazzling effect of the filament 22 and light therefrom is dispersed over a broad area, to give good illumination.
  • FIG. 11 shows a lamp as viewed in the direction of the central axis of the bulb.
  • the width (b) of the segment may be determined in consideration of the bulb radius L, bulb thickness t, depth of depression (At t/2),
  • FIG. 12 shows a lamp as viewed in a horizontal direction.
  • the longitudinal length a of the segment may be determined from the bulb radius L, filament length l, I, At and other factors mentioned before (at 2, At const.).
  • FIG. 13 indicates the relationship of a/b and l/L derived from the aforementioned conditions in FIGS. 11 and 12. Practical application is obtainable in hatched scope of FIG. 13.
  • the segment will assume a shape approximating a square or horizontally elongated rectangle. Then no matter how the angle of inclination 0 at the end portion of the segment is varied, the broadened image of a filament will be readily projected outside of the bulb.
  • the broadened width of the image corresponds to the degree of the angle 0 because a prismatic effect increases with the angle 0. A decreased angle 0 will lead to the occurrence of a striped pattern, whereas an increased angle 6 will lead to a continuous luminous area on the bulb surface. And in both cases, the object of the present invention can not be attained. If the ratio U1.
  • the filament may be regarded approxi mately as a dot-like luminous source, so that the size of the segment or a/b need not be more than 1.2.
  • the length of a straight filament is defined within the range of 3 to 50 mm. from the standpoint of the construction of a mount. Accordingly, if the ratio l/L of more than l/lO is employed in practical application, then the ratio a/b more than 1.2 of the longitudinal to the transverse length of the segment is the range required for the case where the length of the filament can not be overlooked.
  • FIG. 14 represents the relationship of the angle of the inclined plane of the segment and the distance L between the inner wall surface of the bulb and the filament. It is necessary from the standpoint of manufacturing a lamp that the distance L between the filament and bulb be more than 7 to 8 mm. Further, the angle 0 of the inclined plane of the segment is required to be more than 30", because if said angle is smaller than 30 then light will fail to be effectively dispersed from the filament and in consequence tend to be dazzling to the naked eye.
  • FIG. 14 indicates the relationship of L and 0 in case At and t are defined in the same way as described above.
  • the refractive index of bulb glass in practical use is from 1.45 to 1.50 or almost the same as the aforementioned value.
  • the foregoing embodiment has an effect of dispersing without a reflector the source light over a broad area, preventing the filament image from being directly projected and offering beautiful and comfortable illumination free from glare.
  • the present invention is not confined to the aforesaid embodiment.
  • some of the segments may be frosted as an exception to the rule of the previously mentioned equation (1) so as partly to remove brilliance.
  • the bulb may assume a spherical or square pyramidic form.
  • the segments formed on a bulb of such particular shape are desired to display a lenticular and prismatic action, the segments may be so formed for working convenience as to allow tangential lines at both ends of the segment to have an equal angle of inclination or such an angle of inclination as has been averaged from the normally different angles defined by said tangential lines.
  • each of the segments formed at least in one portion of the bulb surface is partly frosted.

Landscapes

  • Non-Portable Lighting Devices Or Systems Thereof (AREA)
US873517A 1968-11-04 1969-11-03 Illuminating lamp having concave segments on exterior bulb surface Expired - Lifetime US3652892A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP8025268 1968-11-04
JP1968097517U JPS472552Y1 (enrdf_load_stackoverflow) 1968-11-11 1968-11-11

Publications (1)

Publication Number Publication Date
US3652892A true US3652892A (en) 1972-03-28

Family

ID=26421290

Family Applications (1)

Application Number Title Priority Date Filing Date
US873517A Expired - Lifetime US3652892A (en) 1968-11-04 1969-11-03 Illuminating lamp having concave segments on exterior bulb surface

Country Status (3)

Country Link
US (1) US3652892A (enrdf_load_stackoverflow)
DE (1) DE1955421A1 (enrdf_load_stackoverflow)
FR (1) FR222560A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4656386A (en) * 1985-03-13 1987-04-07 General Electric Company R lamp having an improved dome portion for increasing the useful light output
USD321404S (en) 1990-03-29 1991-11-05 Falburg Films Corporation Light bulb
WO2011030335A2 (en) 2009-09-10 2011-03-17 Yosef Shterenberg Light bulbs with surface patterns
EP3678160A1 (en) * 2018-10-19 2020-07-08 Duraluce di Coianiz Fabio Lamp with shielding in form of text or graphical symbols

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR421040A (fr) * 1909-10-04 1911-02-13 Ernest Leon Frenot Réflecteur pour ampoules électriques
GB425485A (en) * 1933-09-15 1935-03-15 Bertram Bernard Fenn Improvements in or relating to incandescent electric lamps
US2973451A (en) * 1959-09-03 1961-02-28 Westinghouse Electric Corp Electric lamp
GB1082841A (en) * 1964-08-14 1967-09-13 Gen Electric Co Ltd Improvements in or relating to electric lamps having vitreous silica envelopes

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR421040A (fr) * 1909-10-04 1911-02-13 Ernest Leon Frenot Réflecteur pour ampoules électriques
GB425485A (en) * 1933-09-15 1935-03-15 Bertram Bernard Fenn Improvements in or relating to incandescent electric lamps
US2973451A (en) * 1959-09-03 1961-02-28 Westinghouse Electric Corp Electric lamp
GB1082841A (en) * 1964-08-14 1967-09-13 Gen Electric Co Ltd Improvements in or relating to electric lamps having vitreous silica envelopes

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4656386A (en) * 1985-03-13 1987-04-07 General Electric Company R lamp having an improved dome portion for increasing the useful light output
USD321404S (en) 1990-03-29 1991-11-05 Falburg Films Corporation Light bulb
WO2011030335A2 (en) 2009-09-10 2011-03-17 Yosef Shterenberg Light bulbs with surface patterns
EP3678160A1 (en) * 2018-10-19 2020-07-08 Duraluce di Coianiz Fabio Lamp with shielding in form of text or graphical symbols

Also Published As

Publication number Publication date
DE1955421A1 (de) 1970-07-16
FR222560A (enrdf_load_stackoverflow)

Similar Documents

Publication Publication Date Title
US4118763A (en) Variable transmission prismatic refractors
US3721818A (en) Ceiling mounted luminaire and light-transmitting enclosure therefor
US5363009A (en) Incandescent light with parallel grooves encompassing a bulbous portion
US4855886A (en) Luminaire having a faceted reflecting surface
US3329812A (en) Luminaire optical assembly
US3020395A (en) Lighting device
US2904673A (en) Light diffusors for illuminating devices
US3234376A (en) Glare-free lighting fixture
CA1095575A (en) Ellipsoidal reflector lamp
US2591661A (en) Reflector for controlling at a predetermined angle direct and reflected rays from a light source
JPH03173005A (ja) リフレクタ並びにそれを含む照明装置
US2318716A (en) Luminaire
JP2000511688A (ja) 照明器具
US2418195A (en) Luminaire
JPH1166917A (ja) 自動車用指示灯
US3283140A (en) Street luminaire
US2486558A (en) Street lighting luminaire and refractor therefor
EP0071230A1 (en) Lighting apparatus
US3652892A (en) Illuminating lamp having concave segments on exterior bulb surface
US5278744A (en) Illumination device and luminaire for use therein
CN112254026A (zh) 一种防眩灯具以及采用该灯具的照明布置方法
US1981329A (en) Lamp
US3001062A (en) Light refractor
USRE30832E (en) Ellipsoidal reflector lamp
US2782297A (en) Light projection device