ES2182413T3 - Reflector de tubo de destellos luminosos con guia de arco. - Google Patents

Reflector de tubo de destellos luminosos con guia de arco.

Info

Publication number
ES2182413T3
ES2182413T3 ES99103301T ES99103301T ES2182413T3 ES 2182413 T3 ES2182413 T3 ES 2182413T3 ES 99103301 T ES99103301 T ES 99103301T ES 99103301 T ES99103301 T ES 99103301T ES 2182413 T3 ES2182413 T3 ES 2182413T3
Authority
ES
Spain
Prior art keywords
arc guide
reflector
tube
flash tube
reflector structure
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
ES99103301T
Other languages
English (en)
Inventor
Bradley Scott Thomas
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.)
Becton Dickinson and Co
Original Assignee
Becton Dickinson and Co
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
Application filed by Becton Dickinson and Co filed Critical Becton Dickinson and Co
Application granted granted Critical
Publication of ES2182413T3 publication Critical patent/ES2182413T3/es
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V7/00—Reflectors for light sources
    • F21V7/005—Reflectors for light sources with an elongated shape to cooperate with linear light sources
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/10—Shields, screens, or guides for influencing the discharge
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/04—Investigating sedimentation of particle suspensions
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/025—Associated optical elements

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Investigating Or Analysing Biological Materials (AREA)
  • Stroboscope Apparatuses (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Radiation-Therapy Devices (AREA)
  • Discharge Lamps And Accessories Thereof (AREA)
  • Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)

Abstract

UNA COMBINACION DE REFLECTOR (16) Y GUIA DE ARCO PARA UTILIZAR CON UN TUBO DE FLASH DE XENON (18) QUE COMPRENDE UNA ESTRUCTURA REFLECTORA (58) CON UNA SUPERFICIE REFLECTORA (62) ADAPTADA PARA SER COLOCADA EN UNA ORIENTACION PREDETERMINADA CON RESPECTO AL TUBO DE FLASH (18). UNA GUIA DE ARCO ELECTRICAMENTE CONDUCTORA ESTA DISPUESTA Y PREFERIBLEMENTE FORMA UNA SOLA PIEZA CON LA ESTRUCTURA DEL REFLECTOR (58) PARA CONTROLAR EL ARCO EN EL TUBO DE FLASH (18). LA GUIA DE ARCO COMPRENDE UN BORDE ALARGADO (64) QUE SOBRESALE HACIA FUERA DE LA SUPERFICIE REFLECTORA (62) DE LA ESTRUCTURA DEL REFLECTOR (58), Y SE EXTIENDE EN DIRECCION BASICAMENTE PARALELA CON EL EJE LONGITUDINAL DEL TUBO DE FLASH (18). LA ESTRUCTURA DEL REFLECTOR (58) TIENE UN TERMINAL ELECTRICO Y UNA CONEXION ELECTRICA CON LA GUIA DE ARCO PARA PERMITIR QUE SE APLIQUE UN POTENCIAL ELECTRICO A LA GUIA DE ARCO. LA ESTRUCTURA DEL REFLECTOR (58) SE FABRICA PREFERIBLEMENTE DE UN MATERIAL PLASTICO ELECTRICAMENTE CONDUCTOR, PROPORCIONANDO ASICONTINUIDAD ENTRE EL TERMINAL ELECTRICO Y LA GUIA DE ARCO SIN NECESIDAD DE INSTALAR UN CONDUCTOR POR SEPARADO. UNA SUPERFICIE DE REFLECTIVIDAD MODIFICADA, PREFERIBLEMENTE EN FORMA DE UNA SERIE DE RANURAS (68) PUEDEN DISPONERSE EN LA SUPERFICIE REFLECTORA (62) DE LA ESTRUCTURA DEL REFLECTOR (58) PARA DISPERSAR LA INTENSIDAD MAXIMA DEL TUBO DE FLASH (18). EL REFLECTOR QUE SE DESCRIBE (16) ES SENCILLO Y ECONOMICO DE FABRICAR, Y RESULTA ADECUADO PARA UTILIZAR EN SISTEMAS DE HEMATOLOGIA AUTOMATIZADOS EN LAS CUALES UN IMPULSO DE LUZ PROCEDENTE DEL TUBO DE FLASH (18) HACE QUE LAS CAPAS DE CELULAS DE SANGRE TINTADAS DE UN TUBO CAPILAR ADQUIERAN FLUORESCENCIA DE MANERA QUE PUEDA OBTENERSE UN RECUENTO COMPLETO DE LA SANGRE MEDIANTE TECNICAS DE FORMACION DE IMAGEN OPTICA, MIENTRAS QUE SE HACE GIRAR LA MUESTRA DE SANGRE EN UNA CENTRIFUGA.
ES99103301T 1998-03-02 1999-02-19 Reflector de tubo de destellos luminosos con guia de arco. Expired - Lifetime ES2182413T3 (es)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09/032,935 US6030086A (en) 1998-03-02 1998-03-02 Flash tube reflector with arc guide

Publications (1)

Publication Number Publication Date
ES2182413T3 true ES2182413T3 (es) 2003-03-01

Family

ID=21867662

Family Applications (1)

Application Number Title Priority Date Filing Date
ES99103301T Expired - Lifetime ES2182413T3 (es) 1998-03-02 1999-02-19 Reflector de tubo de destellos luminosos con guia de arco.

Country Status (6)

Country Link
US (1) US6030086A (es)
EP (1) EP0940627B1 (es)
CA (1) CA2263235C (es)
DE (1) DE69903761T2 (es)
ES (1) ES2182413T3 (es)
NO (1) NO322820B1 (es)

Families Citing this family (92)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040195955A1 (en) * 2001-07-13 2004-10-07 Gil Teva Gas discharge lamp
AU2008304111B2 (en) * 2007-09-27 2014-04-24 Amgen Inc. Pharmaceutical formulations
EP3381445B1 (en) 2007-11-15 2023-10-25 Amgen Inc. Aqueous formulation of antibody stablised by antioxidants for parenteral administration
AU2009206306B2 (en) 2008-01-25 2013-06-06 Amgen Inc. Ferroportin antibodies and methods of use
EP2349332B1 (en) 2008-11-13 2019-10-23 The General Hospital Corporation Methods and compositions for regulating iron homeostasis by modulation bmp-6
US20100273384A1 (en) * 2009-04-27 2010-10-28 Ge Healthcare Bio-Sciences Ab Method for aligning a lamp arc in an optical device
MX344382B (es) 2009-10-23 2016-12-14 Amgen Inc * Adaptador de vial y sistema.
ES2545411T5 (es) 2010-06-07 2024-04-05 Amgen Inc Dispositivo de administración de fármaco
JP2012194304A (ja) * 2011-03-16 2012-10-11 Panasonic Corp ストロボ装置
CA2831100C (en) 2011-03-31 2020-02-18 Mark Dominis Holt Vial adapter and system
CA3021845C (en) 2011-04-20 2022-03-29 Amgen Inc. Autoinjector apparatus
LT3045187T (lt) 2011-10-14 2019-07-10 Amgen Inc. Injekcijų įrenginys ir surinkimo būdas
SI3081249T1 (sl) 2012-11-21 2021-03-31 Amgen Inc. Naprava za dajanje zdravila
TWI580451B (zh) 2013-03-15 2017-05-01 安美基公司 用於注射器之匣盒及使用具有自動注射器及匣盒之自動注射器設備之方法
CN105142695B (zh) 2013-03-15 2020-06-02 安进公司 身体轮廓可调适的自动注射器装置
EP2968503B1 (en) 2013-03-15 2018-08-15 Intrinsic LifeSciences LLC Anti-hepcidin antibodies and uses thereof
EP2968775B1 (en) 2013-03-15 2019-12-18 Amgen Inc. Drug cassette, autoinjector, and autoinjector system
SG11201507878SA (en) 2013-03-22 2015-10-29 Amgen Inc Injector and method of assembly
EP3060281B1 (en) 2013-10-24 2019-01-30 Amgen Inc. Drug delivery system with temperature-sensitive control
EP3421066B1 (en) 2013-10-24 2021-03-03 Amgen Inc. Injector and method of assembly
US9593825B2 (en) * 2013-10-29 2017-03-14 Microscan Systems, Inc. Illumination system
WO2015119906A1 (en) 2014-02-05 2015-08-13 Amgen Inc. Drug delivery system with electromagnetic field generator
JP6640113B2 (ja) 2014-05-07 2020-02-05 アムジエン・インコーポレーテツド 衝撃低減要素を有する自動注入器
CN112237662B (zh) 2014-06-03 2022-10-21 安姆根有限公司 药物递送系统和使用方法
WO2016049036A1 (en) 2014-09-22 2016-03-31 Intrinsic Lifesciences Llc Humanized anti-hepcidin antibodies and uses thereof
WO2016061220A2 (en) 2014-10-14 2016-04-21 Amgen Inc. Drug injection device with visual and audio indicators
US11357916B2 (en) 2014-12-19 2022-06-14 Amgen Inc. Drug delivery device with live button or user interface field
EP3848072A1 (en) 2014-12-19 2021-07-14 Amgen Inc. Drug delivery device with proximity sensor
CA2976935C (en) 2015-02-17 2020-03-10 Amgen Inc. Drug delivery device with vacuum assisted securement and/or feedback
WO2016138434A1 (en) 2015-02-27 2016-09-01 Amgen Inc. Drug delivery device having a needle guard mechanism with a tunable threshold of resistance to needle guard movement
WO2017039786A1 (en) 2015-09-02 2017-03-09 Amgen Inc. Syringe assembly adapter for a syringe
ES2755717T3 (es) 2015-12-09 2020-04-23 Amgen Inc Autoinyector con tapa de señalización
US11154661B2 (en) 2016-01-06 2021-10-26 Amgen Inc. Auto-injector with signaling electronics
US11200298B2 (en) 2016-03-15 2021-12-14 Amgen Inc. Reducing probability of glass breakage in drug delivery devices
US11541168B2 (en) 2016-04-29 2023-01-03 Amgen Inc. Drug delivery device with messaging label
WO2017192287A1 (en) 2016-05-02 2017-11-09 Amgen Inc. Syringe adapter and guide for filling an on-body injector
EP3455142B1 (en) 2016-05-13 2023-08-09 Amgen Inc. Vial sleeve assembly
US11238150B2 (en) 2016-05-16 2022-02-01 Amgen Inc. Data encryption in medical devices with limited computational capability
US11541176B2 (en) 2016-06-03 2023-01-03 Amgen Inc. Impact testing apparatuses and methods for drug delivery devices
WO2018004842A1 (en) 2016-07-01 2018-01-04 Amgen Inc. Drug delivery device having minimized risk of component fracture upon impact events
WO2018034784A1 (en) 2016-08-17 2018-02-22 Amgen Inc. Drug delivery device with placement detection
US20200261643A1 (en) 2016-10-25 2020-08-20 Amgen Inc. On-body injector
WO2018136398A1 (en) 2017-01-17 2018-07-26 Amgen Inc. Injection devices and related methods of use and assembly
US11752258B2 (en) 2017-02-17 2023-09-12 Amgen Inc. Drug delivery device with sterile fluid flowpath and related method of assembly
US11369736B2 (en) 2017-02-17 2022-06-28 Amgen Inc. Cannula insertion and retraction mechanisms
CA3050927A1 (en) 2017-03-06 2018-09-13 Brian Stonecipher Drug delivery device with activation prevention feature
KR102627069B1 (ko) 2017-03-07 2024-01-18 암겐 인코포레이티드 과압에 의한 바늘 삽입
EP3592404A1 (en) 2017-03-09 2020-01-15 Amgen Inc. Insertion mechanism for drug delivery device
EP3570871B1 (en) 2017-03-20 2020-11-18 H. Hoffnabb-La Roche Ag Method for in vitro glycoengineering of an erythropoiesis stimulating protein
KR102651078B1 (ko) 2017-03-28 2024-03-22 암겐 인코포레이티드 플런저 로드 및 주사기 조립 시스템 및 방법
JP7200134B2 (ja) 2017-06-08 2023-01-06 アムジエン・インコーポレーテツド トルク駆動式薬物送達デバイス
US11590294B2 (en) 2017-06-08 2023-02-28 Amgen Inc. Syringe assembly for a drug delivery device and method of assembly
JP7195276B2 (ja) 2017-06-22 2022-12-23 アムジエン・インコーポレーテツド デバイス起動による衝突／衝撃の低減
MA49461A (fr) 2017-06-23 2020-04-29 Amgen Inc Dispositif électronique d'administration de médicament comprenant un bouchon activé par un ensemble commutateur
MA49562A (fr) 2017-07-14 2020-05-20 Amgen Inc Système d'insertion-rétractation d'aiguille présentant un système à ressort en double torsion
EP3655063A1 (en) 2017-07-21 2020-05-27 Amgen Inc. Gas permeable sealing member for drug container and methods of assembly
MA49677A (fr) 2017-07-25 2021-04-21 Amgen Inc Dispositif d'administration de médicament avec module d'engrenage et procédé d'assemblage associé
US11484648B2 (en) 2017-07-25 2022-11-01 Amgen Inc. Drug delivery device with container access system and related method of assembly
MA49838A (fr) 2017-08-09 2020-06-17 Amgen Inc Systèm de administration de médicaments avec pression hydraulique-pneumatique de chambre
WO2019036181A1 (en) 2017-08-18 2019-02-21 Amgen Inc. BODY INJECTOR WITH STERILE ADHESIVE PATCH
US11103636B2 (en) 2017-08-22 2021-08-31 Amgen Inc. Needle insertion mechanism for drug delivery device
WO2019070472A1 (en) 2017-10-04 2019-04-11 Amgen Inc. FLOW ADAPTER FOR MEDICATION DELIVERY DEVICE
CN111132711B (zh) 2017-10-06 2022-07-01 安进公司 带有联锁组件的药物递送装置及相关组装方法
MA50348A (fr) 2017-10-09 2020-08-19 Amgen Inc Dispositif d'administration de médicament comprenant un ensemble d'entraînement et procédé d'assemblage associé
WO2019090086A1 (en) 2017-11-03 2019-05-09 Amgen Inc. Systems and approaches for sterilizing a drug delivery device
US20200261648A1 (en) 2017-11-06 2020-08-20 Amgen Inc. Drug delivery device with placement and flow sensing
IL273664B1 (en) 2017-11-06 2026-02-01 Amgen Inc Full-fledged assemblies and related methods
IL319987A (en) 2017-11-10 2025-06-01 Amgen Inc Plungers for drug delivery devices
SG11202003004RA (en) 2017-11-16 2020-04-29 Amgen Inc Door latch mechanism for drug delivery device
AU2018368338B2 (en) 2017-11-16 2024-07-25 Amgen Inc. Autoinjector with stall and end point detection
CN112351841B (zh) 2018-05-04 2023-08-15 泽农公司 提供均匀光能的反射器
US10835685B2 (en) 2018-05-30 2020-11-17 Amgen Inc. Thermal spring release mechanism for a drug delivery device
US11083840B2 (en) 2018-06-01 2021-08-10 Amgen Inc. Modular fluid path assemblies for drug delivery devices
WO2020023220A1 (en) 2018-07-24 2020-01-30 Amgen Inc. Hybrid drug delivery devices with tacky skin attachment portion and related method of preparation
WO2020023336A1 (en) 2018-07-24 2020-01-30 Amgen Inc. Hybrid drug delivery devices with grip portion
CA3103681A1 (en) 2018-07-24 2020-01-30 Amgen Inc. Delivery devices for administering drugs
WO2020023451A1 (en) 2018-07-24 2020-01-30 Amgen Inc. Delivery devices for administering drugs
EP3829692A1 (en) 2018-07-31 2021-06-09 Amgen Inc. Fluid path assembly for a drug delivery device
EP3856284A1 (en) 2018-09-24 2021-08-04 Amgen Inc. Interventional dosing systems and methods
MA53718A (fr) 2018-09-28 2022-01-05 Amgen Inc Ensemble d'activation d'échappement de fil de muscle pour un dispositif d'administration de médicament
MX2021003492A (es) 2018-10-02 2021-06-18 Amgen Inc Sistemas de inyeccion para la administracion de farmacos con transmision de fuerza interna.
JP7547325B2 (ja) 2018-10-05 2024-09-09 アムジエン・インコーポレーテツド 投薬量インジケータを有する薬物送達デバイス
AU2019359801B2 (en) 2018-10-15 2025-01-02 Amgen Inc. Platform assembly process for drug delivery device
SG11202103800RA (en) 2018-10-15 2021-05-28 Amgen Inc Drug delivery device having damping mechanism
MA54057A (fr) 2018-11-01 2022-02-09 Amgen Inc Dispositifs d'administration de médicament à rétraction partielle d'élément d'administration de médicament
TWI831847B (zh) 2018-11-01 2024-02-11 美商安進公司 部分針頭縮回之藥物遞送裝置及其操作方法
ES3010833T3 (en) 2018-11-01 2025-04-04 Amgen Inc Drug delivery devices with partial drug delivery member retraction
AU2020263289B2 (en) 2019-04-24 2025-05-22 Amgen Inc. Syringe sterilization verification assemblies and methods
MX2022002149A (es) 2019-08-23 2022-03-17 Amgen Inc Dispositivo de suministro de farmacos con componentes de acoplamiento de capuchon de aguja configurable y metodos relacionados.
MX2023013640A (es) 2021-05-21 2023-11-30 Amgen Inc Metodo de optimizacion de una receta de llenado para un contenedor de medicamento.
KR20250099137A (ko) 2022-11-02 2025-07-01 에프. 호프만-라 로슈 아게 당단백질 조성물의 생산 방법
WO2026030152A1 (en) 2024-07-29 2026-02-05 Amgen Inc. System and method for assessing transferability of a fill recipe

Family Cites Families (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3199775A (en) * 1963-11-26 1965-08-10 Kenneth G Drucker Sedimentation rate centrifuge and method determining sedimentation rate
US3741011A (en) * 1971-05-28 1973-06-26 Evertz E Method and apparatus for measuring the internal volume of moulds and similar cavity members
FR2270557B1 (es) * 1974-05-10 1976-12-24 Anvar
US4027660A (en) * 1976-04-02 1977-06-07 Wardlaw Stephen C Material layer volume determination
US4156570A (en) * 1977-04-18 1979-05-29 Robert A. Levine Apparatus and method for measuring white blood cell and platelet concentrations in blood
JPS5455821U (es) * 1977-09-27 1979-04-18
FR2484077B1 (fr) * 1980-06-06 1984-07-06 Inst Nat Sante Rech Med Procede et dispositif de mesure de la deformabilite de cellules vivantes, notamment des globules rouges du sang
US4434385A (en) * 1980-06-30 1984-02-28 Matsushita Electric Works, Ltd. Discharge lamp device
JPS5861469A (ja) * 1981-10-08 1983-04-12 Mochida Pharmaceut Co Ltd 免疫学的反応装置
US4558947A (en) * 1983-11-07 1985-12-17 Wardlaw Stephen C Method and apparatus for measuring blood constituent counts
US4555183A (en) * 1984-02-06 1985-11-26 Reese Scientific Corporation High speed test tube agitator apparatus
US4567754A (en) * 1985-03-29 1986-02-04 Wardlaw Stephen C Measurement of small heavy constituent layer in stratified mixture
US4774965A (en) * 1987-07-01 1988-10-04 Becton Dickinson And Co., Inc. Material layer volume determination with correction band
US4823624A (en) * 1987-07-01 1989-04-25 Becton Dickinson & Company Material layer volume determination with correction band
EP0324651A1 (en) * 1988-01-14 1989-07-19 Gte Products Corporation High intensity discharge light sources utilizing magnetic or electric field for control of arc position
US5195825A (en) * 1988-05-09 1993-03-23 Gene-Trak Systems Device for mixing at least one aqueous fluid substance
US4848917A (en) * 1988-08-26 1989-07-18 E. I. Du Pont De Nemours And Company Automatic vortex mixer
US5293021A (en) * 1991-08-02 1994-03-08 Tasman Manor Pty. Ltd. Egg poacher for microwave oven
US5380087A (en) * 1992-09-23 1995-01-10 Habley Medical Technology Corporation Pharmaceutical mixing container with rotationally mounted housing
US5888184A (en) 1997-03-10 1999-03-30 Robert A. Levine Method for rapid measurement of cell layers
US5889584A (en) 1997-03-10 1999-03-30 Robert A. Levine Assembly for rapid measurement of cell layers

Also Published As

Publication number Publication date
DE69903761D1 (de) 2002-12-12
NO990993D0 (no) 1999-03-01
CA2263235A1 (en) 1999-09-02
NO990993L (no) 1999-09-03
DE69903761T2 (de) 2003-07-17
NO322820B1 (no) 2006-12-11
US6030086A (en) 2000-02-29
CA2263235C (en) 2002-07-30
EP0940627B1 (en) 2002-11-06
EP0940627A1 (en) 1999-09-08

Similar Documents

Publication Publication Date Title
US9551480B2 (en) Tubular LED lamp with flexible circuit board
US9170007B2 (en) LED lighting device and system
CA2263235A1 (en) Flash tube reflector with arc guide
ATE330169T1 (de) Beleuchtungseinrichtung
CN102472433A (zh) 具有发光二极管的发光装置
KR20070034952A (ko) 축방향 정렬에서 직접 옵티칼 커플링을 갖는 ｌｅｄ 램프
US10107460B2 (en) Method and system for retrofitting luminaires
EP2341279A2 (en) Optical light guide
TW201248061A (en) Connecting member and LED lamp using the same
JP5016587B2 (ja) Ｌｅｄランプ
US20200217462A1 (en) Light-emitting diode-type illumination device
EP3361148B1 (en) Frame for supporting a light guide panel and luminaire comprising the frame
JP2025090850A (ja) 滑走路埋込型閃光装置及び熱伝導部材
CN105428547A (zh) 具有分段oled二极管的多功能发光模块
WO2019062884A1 (en) LED BULB
CN1625666A (zh) 用于边界照明的装置及其制造方法
JP4812828B2 (ja) Ｌｅｄ照明装置
CN104373907A (zh) 连接件以及照明装置
EP1893913B1 (en) Replaceable vehicle lamp with led light sources
AU2020204248B2 (en) Led lamp
CN107166232A (zh) 照明器具
CN217057187U (zh) 外壳表面自发光的照明装置
CN101101090A (zh) 照明装置
CN102667308B (zh) 照明装置
CN213177794U (zh) 一种防眩光条形灯