GB2220735A - Light emitting diode torch - Google Patents
Light emitting diode torch Download PDFInfo
- Publication number
- GB2220735A GB2220735A GB8815842A GB8815842A GB2220735A GB 2220735 A GB2220735 A GB 2220735A GB 8815842 A GB8815842 A GB 8815842A GB 8815842 A GB8815842 A GB 8815842A GB 2220735 A GB2220735 A GB 2220735A
- Authority
- GB
- United Kingdom
- Prior art keywords
- torch
- light emitting
- emitting diode
- led
- torch according
- 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- Withdrawn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
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21L—LIGHTING DEVICES OR SYSTEMS THEREOF, BEING PORTABLE OR SPECIALLY ADAPTED FOR TRANSPORTATION
- F21L4/00—Electric lighting devices with self-contained electric batteries or cells
- F21L4/02—Electric lighting devices with self-contained electric batteries or cells characterised by the provision of two or more light sources
- F21L4/022—Pocket lamps
- F21L4/027—Pocket lamps the light sources being a LED
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- F21Y2115/00—Light-generating elements of semiconductor light sources
- F21Y2115/10—Light-emitting diodes [LED]
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Illuminated Signs And Luminous Advertising (AREA)
Abstract
The torch uses a light emitting diode (LED) in place of a bulb and produces a light which may be red, green or yellow. The LED may be wired directly into the torch or fitted into a screw, bayonet or other bulb fitting in place of the bulb. The LED in such a fitting may also be used with a limiting resistor.
Description
IMPROVEMENTS IN TORCHES
This invention relates to an improved torch particularly. though not exclusively, for use by military personnel on night exercises.
In army exercises conducted by night, a low level of light is required for map reading, but the light needs to be red in colour i order to avoid attracting attention to the usr of the torch. Conventional torches issued to servicemen are relatively bulky, ad have an incandescent filament bulb. For night exercises, that bulb has to be viewed through a red filter, which means that the light and hence the power store in the battery is used inefficiently. The weight of -the heavy torch and batteries contributes to fatigue on a long march.
Th irlventiorl relates to a torch fitted with an ultra-bright or high intensity light emitting diode.
The light emitting diode may emit green or yellow light. but red is preferred. Peak wavelengths are about 635 rim (red), 565 n. (green) and 583 nm(yellow). A high intensity LED has an intensity at IFtyp of 25-30 mcd, whereas the corresponding intensity for an ultra-bright LED is 124-140 mcd. A low intensity LED emits about 4 mcd at Tftyp, The diode may be fitted into a small pocket torch of generally cylindrical form powered by two AA (HP 7) or AAA (HP 16) cells and may have a pen-type clip for fitting into a jacket pocket, rather than having to be carried in the bergen or webbing It is much lighter and smaller than a conventional torch for this purpose.
The use of light emitting diodes brings a number of advantages. Owing to the low current consumption of the LEd.
the batteries of the torch can last about 10-20 times as long at in a conventional torch with an incandescent filament bulb. Since there is no incandescent bulb, there is no filament to break, the torch is more robust and replacement bulbs do not have to be carried. The light produced is of the intensity required for night map reading and is more diffuse than the light from an incandescent bulb. Replacemerlt batteries are also smaller.
Because of the low current drain, the torch is likely to romain usalçle if left on accidentally overnight. and will run on batteries that are considered flat for other pirpo';es I t is believed that a pent wight torch will run for about 2 days continuous use whereas an normal army torch if fitted with an LED could last for about 16 days continuous use. A conventional torch produces 3 volts from its batteries. The working voltage range of the LED is 2.2-5 volts, and it will continue to operate when the batteries are considered flat for an incandescent bulb.In an incandescent bulb, the illumination produced depends on the square of the curren-t through the filament. so that once the battery voltage starts to drop. the bulb quickly dims.
Current is also limited by the internal resistance of the battery. With an LED, current drain is minimal compared to that of an incandescent lamp, battery resistance is less significartt. and a good light output is obtained provided that the working voltage of the diode is available.
According to a further feature of the invention the
LED may be used as a direct replacement in a conventional torch having an incandescent bulb. For that purpose, the LED is fitted to a contact thimble having a screw or bayonet fitting e.g. an 11 mm MEAS L23 or 5 mm LES L25 screw fitting or an 11 mm MBC L24 bayonet fitting. It may be used in a service torch type bulb holder where there is a metal body having a lip around its top edge. It may also be a replacement for a vehicle panel indicator light bulb, though it may require to be used in association with R lirt!iting resisLor so that the lED is compatible with the 12-volt system of a vehicle. The lED may be used in a repl acemeril for a bulb of the pre-focused type.
Although the initial use of the torch has been considered to be military, the torch could be used for night.
map reading in a car or lorry where its low red light would minimally distract the driver, and it could be used by hikers and mountaineers and for other recreational purposes.
Claims (13)
1. A torch fitted with an ultra-bright or high
intensity light emitting diode.
2. A torch according to claim 1, wherein the LED emits
light at about 635 nm.
3. A torch according to claim 1 or 2, wherein the light
emitting diode is a high intensity LED having an intensity
at iptyp of 25-30 mcd.
4. A torch according to claim 1 or 2, wherein the
light emitting diode is an ultra-bright LED having an
intensity at IFmax of 124-140 mcd.
5. A small pocket torch according to any of claims 1- '1, which is of generally cylindrical form and is powered by
two AA (P 7) or AAA (HP 16) cells.
6. A small pocket torch according to claim 5 which
has a pen-type clip for fitting into a pocket.
7. A torch according to any preceding claim. wherein
the t.F.D T t. fitted to a contact thi mhl e having a screw or
bayonet fitting.
8. A torch according to claim 7, wherein the contact thimble has an 11 mm MAS L23 or 5 mm LES L25 fitting.
9. The use of a torch as claimed in any of claims 108 for map reading.
10. A torch bulb contact thimble fitted with an LED in place of an incandescent bulb.
11. A torch fitted with a light emitting diode.
12. A torch according to claim 11, wherein the Light emitting diode is has an intensity at Iptyp of at least 15 mcd.
13. A torch according to claim 11 or 12 which is a pocket torch.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8815842A GB2220735A (en) | 1988-07-04 | 1988-07-04 | Light emitting diode torch |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8815842A GB2220735A (en) | 1988-07-04 | 1988-07-04 | Light emitting diode torch |
Publications (2)
Publication Number | Publication Date |
---|---|
GB8815842D0 GB8815842D0 (en) | 1988-08-10 |
GB2220735A true GB2220735A (en) | 1990-01-17 |
Family
ID=10639822
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8815842A Withdrawn GB2220735A (en) | 1988-07-04 | 1988-07-04 | Light emitting diode torch |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2220735A (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE9101795U1 (en) * | 1991-02-16 | 1991-09-12 | Strathausen, Gerold, 8301 Bruckberg | Grave light |
ES2056713A2 (en) * | 1991-11-25 | 1994-10-01 | Lintled S L | Portable electric lighting system |
WO1995023313A1 (en) * | 1994-02-23 | 1995-08-31 | Adm-Delta Limited | Warning light |
GB2336657A (en) * | 1998-04-09 | 1999-10-27 | Iain Sinclair | Overrunning maximum voltage/current levels of a hight resistance LED in a light. |
WO2000060277A1 (en) * | 1999-04-03 | 2000-10-12 | Buenting Gerd | Signalling light with light-emitting diode |
GB2327753B (en) * | 1997-07-07 | 2000-10-18 | Paul Murley | Firefighter's Hand Lamp |
GB2361378A (en) * | 2000-04-14 | 2001-10-17 | Trevor Beale | Mobile phone incorporating a high output led torch |
US6357890B1 (en) | 2000-09-01 | 2002-03-19 | Armament Systems And Procedures, Inc. | Miniature LED flashlight |
US6749317B1 (en) | 1999-01-06 | 2004-06-15 | Armament Systems And Procedures, Inc. | Miniature led flashlight |
US6786616B1 (en) | 1999-01-06 | 2004-09-07 | Armament Systems And Procedures, Inc. | LED flashlight with switch separate from panel |
US6796672B2 (en) | 1999-01-06 | 2004-09-28 | Armament Systems And Procedures, Inc. | LED flashlight with interlocking clip |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4228484A (en) * | 1978-12-04 | 1980-10-14 | Johnstone Malcolm D | LED flasher for battery cell-powered lamp |
US4409643A (en) * | 1982-03-23 | 1983-10-11 | Frank Alan M | Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings |
WO1985005432A1 (en) * | 1984-05-16 | 1985-12-05 | The Commonwealth Of Australia Care Of The Secretar | A low-light miniature flash light |
US4808261A (en) * | 1986-04-29 | 1989-02-28 | Sgs Microelettronica S.P.A. | Fabrication process for EPROM cells with oxide-nitride-oxide dielectric |
-
1988
- 1988-07-04 GB GB8815842A patent/GB2220735A/en not_active Withdrawn
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4228484A (en) * | 1978-12-04 | 1980-10-14 | Johnstone Malcolm D | LED flasher for battery cell-powered lamp |
US4409643A (en) * | 1982-03-23 | 1983-10-11 | Frank Alan M | Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings |
WO1985005432A1 (en) * | 1984-05-16 | 1985-12-05 | The Commonwealth Of Australia Care Of The Secretar | A low-light miniature flash light |
US4808261A (en) * | 1986-04-29 | 1989-02-28 | Sgs Microelettronica S.P.A. | Fabrication process for EPROM cells with oxide-nitride-oxide dielectric |
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE9101795U1 (en) * | 1991-02-16 | 1991-09-12 | Strathausen, Gerold, 8301 Bruckberg | Grave light |
ES2056713A2 (en) * | 1991-11-25 | 1994-10-01 | Lintled S L | Portable electric lighting system |
WO1995023313A1 (en) * | 1994-02-23 | 1995-08-31 | Adm-Delta Limited | Warning light |
GB2327753B (en) * | 1997-07-07 | 2000-10-18 | Paul Murley | Firefighter's Hand Lamp |
GB2336657B (en) * | 1998-04-09 | 2001-01-24 | Iain Sinclair | Improvements in or relating to electric lights |
GB2336657A (en) * | 1998-04-09 | 1999-10-27 | Iain Sinclair | Overrunning maximum voltage/current levels of a hight resistance LED in a light. |
US6951410B2 (en) | 1999-01-06 | 2005-10-04 | Armament Systems And Procedures, Inc. | LED flashlight with die-struck panel |
US6991344B2 (en) | 1999-01-06 | 2006-01-31 | Armament Systems & Procedures, Inc. | LED flashlight having a clip made of a resilient material |
US6959997B2 (en) | 1999-01-06 | 2005-11-01 | Armament Systems & Procedures, Inc. | LED flashlight having a dissimilar frame and panel |
US6749317B1 (en) | 1999-01-06 | 2004-06-15 | Armament Systems And Procedures, Inc. | Miniature led flashlight |
US6786616B1 (en) | 1999-01-06 | 2004-09-07 | Armament Systems And Procedures, Inc. | LED flashlight with switch separate from panel |
US6796672B2 (en) | 1999-01-06 | 2004-09-28 | Armament Systems And Procedures, Inc. | LED flashlight with interlocking clip |
US6857757B2 (en) | 1999-01-06 | 2005-02-22 | Armament Systems And Procedures, Inc. | LED flashlight with side panels inside structure |
US6860615B2 (en) | 1999-01-06 | 2005-03-01 | Armament Systems And Procedures, Inc. | LED flashlight with integral keyring clip |
US6945667B2 (en) | 1999-01-06 | 2005-09-20 | Armament Systems & Procedures, Inc. | LED flashlight with medallion in panel |
WO2000060277A1 (en) * | 1999-04-03 | 2000-10-12 | Buenting Gerd | Signalling light with light-emitting diode |
GB2361378A (en) * | 2000-04-14 | 2001-10-17 | Trevor Beale | Mobile phone incorporating a high output led torch |
US6357890B1 (en) | 2000-09-01 | 2002-03-19 | Armament Systems And Procedures, Inc. | Miniature LED flashlight |
Also Published As
Publication number | Publication date |
---|---|
GB8815842D0 (en) | 1988-08-10 |
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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) |