GB2035681A - A coated light bulb for a headlamp - Google Patents
A coated light bulb for a headlamp Download PDFInfo
- Publication number
- GB2035681A GB2035681A GB7939115A GB7939115A GB2035681A GB 2035681 A GB2035681 A GB 2035681A GB 7939115 A GB7939115 A GB 7939115A GB 7939115 A GB7939115 A GB 7939115A GB 2035681 A GB2035681 A GB 2035681A
- Authority
- GB
- United Kingdom
- Prior art keywords
- capsule
- coating
- low beam
- beam filament
- filament
- 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.)
- Withdrawn
Links
- 239000011248 coating agent Substances 0.000 claims abstract description 40
- 238000000576 coating method Methods 0.000 claims abstract description 40
- 230000004313 glare Effects 0.000 claims abstract description 21
- 230000005855 radiation Effects 0.000 claims abstract description 11
- 239000002775 capsule Substances 0.000 claims description 66
- 229910052736 halogen Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 8
- 239000011521 glass Substances 0.000 claims description 4
- 238000005286 illumination Methods 0.000 claims description 4
- 230000000903 blocking effect Effects 0.000 claims description 2
- 238000007598 dipping method Methods 0.000 claims description 2
- 238000010304 firing Methods 0.000 claims description 2
- 150000002367 halogens Chemical class 0.000 claims description 2
- 239000007788 liquid Substances 0.000 claims description 2
- 238000005259 measurement Methods 0.000 claims description 2
- 239000000725 suspension Substances 0.000 claims description 2
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01K—ELECTRIC INCANDESCENT LAMPS
- H01K9/00—Lamps having two or more incandescent bodies separately heated
- H01K9/08—Lamps having two or more incandescent bodies separately heated to provide selectively different light effects, e.g. for automobile headlamp
Landscapes
- Non-Portable Lighting Devices Or Systems Thereof (AREA)
Abstract
In a lamp bulb (2), suitable for use in a headlamp, and which contains a low beam filament (5) and a high beam filament (4), the upper forward end of the bulb (2) is coated with an opaque coating (8) in order to shield veiling glare radiation from the low beam filament when the bulb is used in a headlamp. <IMAGE>
Description
SPECIFICATION
Headlight containing shielded lamp capsule
This invention is concerned with automobile headlights comprising a tungsten-halogen lamp within a reflector. Examples of such headlights are disclosed in copending Application Nos. 7097753 and 7914955, (Serial No's 2015822 2019998) the disclosures of which are incorporated herein by reference. The invention is particularly concerned with Type 2 headlights, that is to say, those having both a high beam and a low beam filament, and is especially concerned with reducing veiling glare from the low beam filament. Veiling glare is considered to be the part of the light beam pattern that is in the 10 up to 90 up range, as specified in SAE Standard J579c entitled "Sealed Beam Headlight Units for Motor
Vehicles". The veiling glare problem is discussed in
U.S.A.Patent Specification No. 4,029,985, which discloses the use of a metal shield forward of the filamentto reduce veiling glare. U.S.A. PatentSpecification No. 3,904,904 discloses the use of a metal shield in front of a tungsten-halogen capsule to reduce veiling glare. U.S.A. Patent Specification No.
3,784,861 discloses the use of an opaque coating on the entire forward end of a capsule to reduce veiling glare.
This invention is concerned with solving the veiling glare problem without using extra mechanical parts, such as metal shields, which can cause vibration problems. According to the invention an opaque coating is provided on the forward end of a tungsten-halogen capsule, similar to that disclosed in U.S.A. Patent Specification No. 3,784,861, but the coating is shaped in such a manner as to desirably obtain some direct side lighting from the low beam filament, which the complete circumferential coating of U.S.A. Patent Specification No. 3,784,861 does not provide. U.S.A. Patent Specification No. 3,153,741 discusses the desirability of providing side lighting from a low beam filament and discloses a metal shield for that purpose, there being a cut-out in the shield that permits direct forward illumination from the filament.In said Patent, the shield having the tapering cut-out that provides the desirable side lighting is located below the low beam filament. In the present invention, the shielding coating is located above the low beam filament.
Ths invention is illustrated by way of example in the accompanying drawings, in which:
Figure lisa perspective view of a headlight in accordance with this invention, showing a coated capsule in a reflector,
Figure 2 is a plan view of the capsule, and
Figure 3 is an end view of the coated end of the capsule.
As shown in the drawings, a headlight 1 comprises a tungsten-halogen capsule 2 within a parabolic reflector 3. The capsule 2 contains two filaments, a low beam filament 5 and a high beam filament 4. The capsule 2 has a press seal 6 at one end thereof through which extend lead-in wires 7 for the filaments. The capsule 2 is mounted within the reflector 3 so that the press seal 6 is rearward and one of the filaments is at or near the focus of the reflector 3. The low beam filament 5 is above the high beam filament 4. The upperforward end of the capsule 2 has an opaque coating 8 thereon. The shape and position of the coating 8 is such as to substantially block direct forward radiation from the low beam filament 5 in the 10 up to 90 up direction without substantially blocking direct side lighting from said filament.
Thus, the lower half of the forward end of the capsule 2 should be substantially free of opaque coating.
In one example, the capsule 2 was a tubular glass envelope about 9!16" diameter by 1 1/4" long (including the press seal 6 but excluding the exhaust tip 9).
The filament 5 was substantially orthogonal to, and about 1116" above, the axis ofthe capsule 2 and was 3/8" from the forward end of the capsule 2. The opaque coating 8 was applied to the upper forward end of the capsule 2 by positioning the capsule 2 at an angle of about 30 from the horizontal and dipping the capsule, upper forward end lowermost, into a liquid opaquing suspension at that angle. The coating 8 was then bonded to the glass by firing at 500 to 600"C for a few minutes. As shown in Figure 2 and Figure 3, the coating 8 extended about 3/8" back on the upper surface of the capsule 2 and about 3/16" down on the forward end of the capsule 2.
A comparison of veiling glare radiation from capsules with, and without, opaque coating in accordance with this invention was made. At 10 above the horizontal, the candlepower of the capsules without coating averaged 98 against only 42 for the coated capsules. At 20 , the respective measurements were 60 candlepower against 12 candlepower and at 40", 50 candlepower against 5 and at 60", 12 candlepower against 5. Thus, veiling glare radiation was significantly reduced, without significantly reducing the desired main beam illumination.
1. A tungsten-halogen capsule comprising a transparent envelope containing a low beam filament and a high beam filament, one end of the envelope having an opaque coating thereon such that, in operation in a headlight, the coating shields veiling glare radiation from the low beam filament without shielding direct side lighting therefrom.
2. A capsule as claimed in Claim 1, wherein said coating covers part of the upper surface at the forward end of the capsule.
3. A capsule as claimed in Claim 1, wherein said coating covers part of the upper half of the forward end of the capsule.
4. Atungsten halogen capsule substantially as described herein with reference to the accompanying drawings.
5. A headlight comprising a lamp capsule within a reflector, the capsule containing a low beam filament, the upper and forward end of the capsule being partially coated with an opaque coating.
6. A headlight as claimed in Claim 4, wherein the opaque coating is above and forward of the low beam filament.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (1)
- **WARNING** start of CLMS field may overlap end of DESC **.SPECIFICATION Headlight containing shielded lamp capsule This invention is concerned with automobile headlights comprising a tungsten-halogen lamp within a reflector. Examples of such headlights are disclosed in copending Application Nos. 7097753 and 7914955, (Serial No's 2015822 2019998) the disclosures of which are incorporated herein by reference. The invention is particularly concerned with Type 2 headlights, that is to say, those having both a high beam and a low beam filament, and is especially concerned with reducing veiling glare from the low beam filament. Veiling glare is considered to be the part of the light beam pattern that is in the 10 up to 90 up range, as specified in SAE Standard J579c entitled "Sealed Beam Headlight Units for Motor Vehicles". The veiling glare problem is discussed in U.S.A.Patent Specification No. 4,029,985, which discloses the use of a metal shield forward of the filamentto reduce veiling glare. U.S.A. PatentSpecification No. 3,904,904 discloses the use of a metal shield in front of a tungsten-halogen capsule to reduce veiling glare. U.S.A. Patent Specification No.3,784,861 discloses the use of an opaque coating on the entire forward end of a capsule to reduce veiling glare.This invention is concerned with solving the veiling glare problem without using extra mechanical parts, such as metal shields, which can cause vibration problems. According to the invention an opaque coating is provided on the forward end of a tungsten-halogen capsule, similar to that disclosed in U.S.A. Patent Specification No. 3,784,861, but the coating is shaped in such a manner as to desirably obtain some direct side lighting from the low beam filament, which the complete circumferential coating of U.S.A. Patent Specification No. 3,784,861 does not provide. U.S.A. Patent Specification No. 3,153,741 discusses the desirability of providing side lighting from a low beam filament and discloses a metal shield for that purpose, there being a cut-out in the shield that permits direct forward illumination from the filament.In said Patent, the shield having the tapering cut-out that provides the desirable side lighting is located below the low beam filament. In the present invention, the shielding coating is located above the low beam filament.Ths invention is illustrated by way of example in the accompanying drawings, in which: Figure lisa perspective view of a headlight in accordance with this invention, showing a coated capsule in a reflector, Figure 2 is a plan view of the capsule, and Figure 3 is an end view of the coated end of the capsule.As shown in the drawings, a headlight 1 comprises a tungsten-halogen capsule 2 within a parabolic reflector 3. The capsule 2 contains two filaments, a low beam filament 5 and a high beam filament 4. The capsule 2 has a press seal 6 at one end thereof through which extend lead-in wires 7 for the filaments. The capsule 2 is mounted within the reflector 3 so that the press seal 6 is rearward and one of the filaments is at or near the focus of the reflector 3. The low beam filament 5 is above the high beam filament 4. The upperforward end of the capsule 2 has an opaque coating 8 thereon. The shape and position of the coating 8 is such as to substantially block direct forward radiation from the low beam filament 5 in the 10 up to 90 up direction without substantially blocking direct side lighting from said filament.Thus, the lower half of the forward end of the capsule 2 should be substantially free of opaque coating.In one example, the capsule 2 was a tubular glass envelope about 9!16" diameter by 1 1/4" long (including the press seal 6 but excluding the exhaust tip 9).The filament 5 was substantially orthogonal to, and about 1116" above, the axis ofthe capsule 2 and was 3/8" from the forward end of the capsule 2. The opaque coating 8 was applied to the upper forward end of the capsule 2 by positioning the capsule 2 at an angle of about 30 from the horizontal and dipping the capsule, upper forward end lowermost, into a liquid opaquing suspension at that angle. The coating 8 was then bonded to the glass by firing at 500 to 600"C for a few minutes. As shown in Figure 2 and Figure 3, the coating 8 extended about 3/8" back on the upper surface of the capsule 2 and about 3/16" down on the forward end of the capsule 2.A comparison of veiling glare radiation from capsules with, and without, opaque coating in accordance with this invention was made. At 10 above the horizontal, the candlepower of the capsules without coating averaged 98 against only 42 for the coated capsules. At 20 , the respective measurements were 60 candlepower against 12 candlepower and at 40", 50 candlepower against 5 and at 60", 12 candlepower against 5. Thus, veiling glare radiation was significantly reduced, without significantly reducing the desired main beam illumination.1. A tungsten-halogen capsule comprising a transparent envelope containing a low beam filament and a high beam filament, one end of the envelope having an opaque coating thereon such that, in operation in a headlight, the coating shields veiling glare radiation from the low beam filament without shielding direct side lighting therefrom.2. A capsule as claimed in Claim 1, wherein said coating covers part of the upper surface at the forward end of the capsule.3. A capsule as claimed in Claim 1, wherein said coating covers part of the upper half of the forward end of the capsule.4. Atungsten halogen capsule substantially as described herein with reference to the accompanying drawings.5. A headlight comprising a lamp capsule within a reflector, the capsule containing a low beam filament, the upper and forward end of the capsule being partially coated with an opaque coating.6. A headlight as claimed in Claim 4, wherein the opaque coating is above and forward of the low beam filament.7. A headlight as claimed in Ciaim 5, wherein the coating shields the 10 up to 90 up light radiation from the low beam filament without significantly shielding the direct side light radiation therefrom.9. The features as herein described, or their equivalents, in any novel selection.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96037578A | 1978-11-13 | 1978-11-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2035681A true GB2035681A (en) | 1980-06-18 |
Family
ID=25503091
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7939115A Withdrawn GB2035681A (en) | 1978-11-13 | 1979-11-12 | A coated light bulb for a headlamp |
Country Status (6)
| Country | Link |
|---|---|
| BE (1) | BE879923A (en) |
| DE (1) | DE2945242A1 (en) |
| FR (1) | FR2441795A1 (en) |
| GB (1) | GB2035681A (en) |
| IT (1) | IT1124940B (en) |
| NL (1) | NL7908253A (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3153741A (en) * | 1960-07-08 | 1964-10-20 | Gen Motors Corp | Vehicle headlamp filament shield |
| US3784861A (en) * | 1971-02-25 | 1974-01-08 | Philips Corp | Lamp with opaque screen |
| DE2321709C3 (en) * | 1973-04-28 | 1975-10-16 | Philips Patentverwaltung Gmbh, 2000 Hamburg | Electric spotlights, in particular for use as vehicle headlights, and method for their production |
| IT1026581B (en) * | 1974-11-27 | 1978-10-20 | Philips Spa | RECEIVER FOR BINARY PULSE SIGNAL TRANSMISSION SYSTEM INCLUDING A CIRCUIT FOR THE AUTOMATIC CORRECTION OF DISTURBANCES IN THE DIRECT CURRENT LEVEL |
-
1979
- 1979-11-09 DE DE19792945242 patent/DE2945242A1/en active Granted
- 1979-11-09 IT IT27154/79A patent/IT1124940B/en active
- 1979-11-09 BE BE2/58196A patent/BE879923A/en not_active IP Right Cessation
- 1979-11-12 FR FR7927822A patent/FR2441795A1/en active Granted
- 1979-11-12 NL NL7908253A patent/NL7908253A/en not_active Application Discontinuation
- 1979-11-12 GB GB7939115A patent/GB2035681A/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| NL7908253A (en) | 1980-05-16 |
| BE879923A (en) | 1980-03-03 |
| FR2441795A1 (en) | 1980-06-13 |
| IT7927154A0 (en) | 1979-11-09 |
| IT1124940B (en) | 1986-05-14 |
| FR2441795B3 (en) | 1981-08-21 |
| DE2945242C2 (en) | 1989-01-12 |
| DE2945242A1 (en) | 1980-05-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |