SI21894A

SI21894A - Collecting lens for a projection headlight within a vehicle

Info

Publication number: SI21894A
Application number: SI200400259A
Authority: SI
Inventors: Ales Kralj; Tomaz Logar
Original assignee: Hella Lux Slovenija, Proizvodnja Svetlobne Opremeza Motorna In Druga Vozila, D.O.O.
Priority date: 2004-09-17
Filing date: 2004-09-17
Publication date: 2006-04-30
Also published as: EP1637797A2; EP1637797A3

Abstract

The body of the collecting base (CL) is limited by a smooth surface (SF) and surface (FZF) featuring Fresnel zones, where the Fresnel zone is made by featuring a round or central refraction surface (RRS, CRS) and a round circular surface of the threshold (RCS). Each internal circular edge (ICE) where on the internal side the round refraction surface (RRS) and the adjacent round circular surface (RCF) of the threshold meet, is located on a virtual convex surface (CS), which includes the peripheral edge (PE) of the lens and is convex in the direction of the surface (FZF). The heights (h), measured in the direction parallel to the geometrical lens axis, as well as deviations between the outside circular edges (OCE) and the surface (CS) are as small as possible. The number of N surfaces is defined as 2, smaller or equal to N and smaller or equal to 5. Despite its small weight the collecting lens features excellent properties of a thick collecting lens like high level of light permeability and little dazzle above the light-dark limit, while at the same time it is thin enough that it can also be manufactured by injection moulding from amorphous thermoplastic material.

Description

Izum se nanaša na zbiralno lečo za projekcijski žaromet v cestnem vozilu, katere telo je na vstopni strani omejeno z gladko lečno površino in na izstopni strani s takšno lečno površino s Fresnelovimi zonami, da je prepuščeni svetlobni tok kar največji in se |The invention relates to a collection lens for a projection headlamp in a road vehicle whose body is bounded on the inlet side by a smooth lens surface and on the exit side by such a lens surface with Fresnel zones that the transmittance of light is maximized and is |

zmanjša bleščanje, ki ga zaznajo vozilu nasproti vozeči vozniki, pri čemer ima zbiralna leča majhno maso in se lahko izvede s kratko goriščno razdaljo.Reduces the glare detected by the vehicle opposite the oncoming drivers, whereby the collection lens is small in mass and can be carried out with a short focal length.

Izum je po mednarodni klasifikaciji patentov uvrščen v razred G 02B 03/08.According to the international classification of patents, the invention is classified in class G 02B 03/08.

Naloga izuma je izpopolniti zbiralno lečo za projekcijski žaromet v cestnem vozilu, tako da se pri čim manjši masi zbiralne leče, ki se lahko izvede s kratko goriščno razdaljo, maksimira prepuščeni svetlobni tok in minimira svetlobni tok, ki se na izstopni strani zbiralne leče odkloni iz predvidene smeri.It is an object of the invention to refine the collector lens for a projection headlamp in a road vehicle so as to maximize the transmitted light flux and minimize the light flux deflected at the exit side of the collecting lens at the minimum mass of the collecting lens, which can be carried out with a short focal length predicted directions.

Za projekcijski žaromet v cestnem vozilu se je uveljavila steklena zbiralna leča, ki pa je zaradi postopka izdelave draga komponenta. Na sl. 1 in 2 sta predstavljeni takšni plankonveksna oziroma konkavnokonveksna zbiralna leča z debelino d. Ker ima veliko maso, potrebuje odporno pritrdilno konstrukcijo. Ta je v zadnjem času postala še posebej zahtevna, ker mora biti sklop reflektorja zasučen tako okoli navpične kot tudi vodoravne osi. Zbiralna leča mora imeti še posebej izdelan nosilec, da se fiksira v pravilno lego glede na reflektor in vir svetlobe. Zbiralna leča z manjšo maso bi pripomogla k poenostavitvi celotnega projekcijskega žarometa. V zadnjem času se poskuša nadomestiti stekleno konveksno lečo z zbiralno Fresnelovo lečo.A projector headlamp in a road vehicle has become acclaimed as a glass collector lens, which is an expensive component due to its manufacturing process. In FIG. 1 and 2, such plank-convex or concave-convex collection lenses with thickness d are presented. Because it has a large mass, it requires a robust fastening structure. This has become especially challenging lately because the reflector assembly must be rotated around both the vertical and horizontal axes. The collecting lens must have a specially designed mounting bracket in order to fix it to the correct position with respect to the reflector and the light source. A smaller mass collection lens would help simplify the whole projection headlamp. Recently, an attempt has been made to replace a glass convex lens with a collecting Fresnel lens.

V patentni prijavi DE 198 56 281 je predstavljen projekcijski žaromet za cestno vozilo s konkavnokonveksno, a v bistvu ukrivljeno planparalelno Fresnelovo lečo. Projekcijski žaromet obsega svetlobni vir LS, elipsoidni reflektor R, senčnik S in tankostensko zbiralno Fresnelovo lečo CL' - poenostavljeno je predstavljena kot ravna zbiralna leča (sl. 3). Ta naj bi bila prednostno iz termoplasta. Zbiralna Fresnelova leča dejansko nudi elegantno možnost, da se izdela lahka zbiralna leča iz polimera ali stekla. Žal pa ima tankostenska zbiralna Fresnelova leča majhno prepustnost svetlobnega toka v željeni smeri in blešči. Lečna površina s Fresnelovimi zonami na izstopni strani je namreč izvedena iz številnih obročastih lomečih površin RRS, ki jih preko zunanjih krožnih robov OCE in notranjih krožnih robov ICE - zaradi ulivanja leče ti robovi niso ostri - povezujejo obročaste površine RSS skoka. Višina h predstavlja izstopanje zunanjih krožnih robov OCE od ravnine notranjih krožnih robov ICE. Odboj in lom tako na obročastih površinah RSS skoka kot na zaobljenih zunanjih in notranjih krožnih robovih OCE oziroma ICE povzročajo izgubo vpadlega svetlobnega toka. Zmanjšanje števila Fresnelovih zon ne zmanjša omenjene izgube, saj se obenem poveča omenjena višina h in s tem obročaste površine RSS skoka, naraste pa tudi masa leče. Zaradi loma in odboja na omenjenih številnih kočljivih površinah prihaja tudi do bleščanja nad svetlo-temno mejo v porazdelitvi žarometovega svetlobnega pramena. Omenjene izgube so še posebno velike pri kratkem projekcijskem žarometu, ki ima majhno razsežnost v smeri optične osi, saj v njem na zbiralno lečo žarki vpadajo pod raznolikimi in tudi velikimi vpadnimi koti.DE 198 56 281 discloses a projection headlamp for a road vehicle with a concave convex but essentially curved planar-parallel Fresnel lens. The projection headlamp comprises an LS light source, an ellipsoidal reflector R, an eyeshadow S, and a thin-walled Fresnel lens CL '- it is simplified to be represented as a flat collection lens (Fig. 3). This should preferably be thermoplastic. The Fresnel collection lens actually offers the elegant option of making lightweight polymer or glass collection lenses. Unfortunately, the thin-walled Fresnel collector lens has a low transmittance of light in the desired direction and glare. The lens surface with Fresnel zones on the outlet is derived from the numerous annular fracturing surfaces of the RRS, which, through the outer circular edges of the OCE and the inner circular edges of the ICE, due to the casting of the lens, these edges are not sharp - link the annular surfaces of the RSS jump. The height h represents the projection of the outer circular edges of the OCE from the plane of the inner circular edges of the ICE. Reflection and refraction, both on the annular surfaces of the RSS jump and on the rounded outer and inner circular edges of the OCE and ICE respectively, cause loss of incident light. Reducing the number of Fresnel zones does not reduce this loss, since at the same time the height of the h and thus the annular surface of the RSS jump increases, and the weight of the lens increases. Due to the refraction and reflection on these many sensitive surfaces, there is also a glare over the light-dark boundary in the distribution of the headlamp beam. The aforementioned losses are especially large in the case of a short projection headlamp, which has a small dimension in the direction of the optical axis, because in it the rays are incident at various and also large incident angles.

Navedeni tehnični problem je rešen z zbiralno lečo po izumu za projekcijski žaromet v cestnem vozilu, ki je opredeljena z značilnostmi iz označujočega dela prvega patentnega zahtevka, podzahtevki pa opredeljujejo variantne izvedbene primere.Said technical problem is solved by an assembly lens according to the invention for a projection headlamp in a road vehicle, which is defined by the features of the marking part of the first patent claim, and the sub-claims define variant embodiments.

Z izumom predlagana zbiralna leča za projekcijski žaromet v cestnem vozilu se kljub majhni masi odlikuje z dobrimi lastnostmi debele zbiralne leče, kot so visoka prepustnost svetlobe in malo bleščanja nad svetlo-temno mejo, obenem pa je še dovolj tanka, da se z injekcijskim litjem lahko izdeluje tudi iz amorfnega termoplasta.According to the invention, the collector lens for a projection headlamp in a road vehicle, despite its low mass, is characterized by the good properties of a thick collector lens, such as high light transmittance and low glare above the light-dark boundary, while being thin enough to be cast by injection molding. also made from an amorphous thermoplastic.

Na ugoden način se pri stalnem številu obročastih lomečih površin Fresnelove vrste lahko poljubno zmanjša bleščanje za zbiralno lečo po izumu, s tem da se odebeli predel |In a favorable manner, the constant number of Fresnel annular fracturing surfaces can arbitrarily reduce the glare of the collecting lens of the invention by thickening the region |

med vstopno gladko lečno površino in namišljeno konveksno ploskvijo skozi obodni rob zbiralne leče, pri čemer se zmanjša višina odstopanja zunanjih krožnih robov obročastih lomečih površin glede na namišljeno konveksno ploskev.between the incoming smooth lens surface and the imaginary convex surface through the circumferential edge of the collecting lens, reducing the height of the deviation of the outer circular edges of the annular breaking surfaces relative to the imaginary convex surface.

Zbiralna leča po izumu se odlikuje zlasti pri kratkih goriščnih razdaljah, takšna pa je namenjena za vgraditev v kratek projekcijski žaromet.The collection lens according to the invention is distinguished especially by its short focal lengths, which is intended for mounting in a short projection headlamp.

Izum bo v nadaljnjem podrobno obrazložen na osnovi opisa izvedbenih primerov ter pripadajočega načrta, ki prikazuje na sl. 4 v osnem prerezu zgradbo zbiralne leče po izumu za projekcijski žaromet v cestnem vozilu in sl. 5 geometrijske in optične parametre zbiralne leče po izumu.The invention will now be further explained in detail based on the description of the embodiments and the accompanying plan showing in FIG. 4 is a cross-sectional view of the assembly of the collection lens according to the invention for a projection headlamp in a road vehicle, and FIG. 5 geometric and optical parameters of a collection lens according to the invention.

Telo zbiralne leče CL po izumu za projekcijski žaromet v cestnem vozilu jev osnem prerezu predstavljeno na sl. 4. Na vstopni strani je omejeno z gladko lečno površino SF - s polmerom r pri krogelni površini SF (sl. 5) - in na izstopni strani z lečno površino FZF s Fresnelovimi zonami.The body of the collection lens CL according to the invention for a projection headlamp in a road vehicle in axial cross section is presented in FIG. 4. It is bounded on the inlet side by a smooth lens surface SF - with radius r at the ball sphere SF (Fig. 5) - and on the exit side by a lens surface FZF with Fresnel zones.

Posamezna Fresnelova zona je izvedena z osrednjo lomečo površino CRS ali obročasto lomečo površino RRS in z obročasto površino RS S skoka.The individual Fresnel zone is made with a CRS central breaking surface or an RRS ring breaking surface and an RS S jump ring surface.

Po izumu vsak notranji krožni rob ICE, po katerem se na notranji strani stikata obročasta lomeča površina RRS in sosednja obročasta površina RS S skoka, leži na namišljeni konveksni ploskvi CS.According to the invention, each inner circular edge of the ICE, by which the annular breaking surface RRS and the adjacent annular surface RS of the jump S are connected on the inside, lies on an imaginary convex plane CS.

Na sl. 4 je predstavljen izvedbeni primer po izumu, pri katerem je konveksna ploskev CS krogelna ploskev s polmerom r'.In FIG. 4 is an embodiment of the invention in which the convex plane CS is a sphere with radius r '.

Namišljena konveksna ploskev CS je po izumu najprej opredeljena, s tem da vključuje obodni rob PE zbiralne leče CL in da je izbočena v smeri proti lečni površini FZF s Fresnelovimi zonami.The intended CS convex surface is first defined according to the invention by incorporating the peripheral edge of the PE collecting lens CL and projecting towards the FZF lens surface with Fresnel zones.

Namišljena konveksna ploskev CS je po izumu nadalje opredeljena, s tem daje višina h odstopanja zunanjih krožnih robov OCE od namišljene konveksne ploskve C S kar se da majhna. Višina h se meri v smeri, ki je vzporedna z geometrijsko osjo zbiralne leče CL.The imaginary convex plane CS is further defined according to the invention, so that the height h is the deviation of the outer circular edges of the OCE from the imaginary convex plane C S as small as possible. The height h is measured in a direction parallel to the geometric axis of the CL collection lens.

V prednostnem izvedbenem primeru po izumu je lečna površina FZF s Fresnelovimi zonami izvedena z majhnim številom N obročastih lomečih površin RRS. Število N naj bo enako ali večje od dva in manjše od ali enako pet (2 < N < 5). Pri tem gre za kom5 promis med želj enim prihrankom pri masi zbiralne leče CL po izumu in tehnološkimi omejitvami.In a preferred embodiment of the invention, the FZF lens surface with Fresnel zones is made with a small number of N annular breakable RRS surfaces. The number N should be equal to or greater than two and less than or equal to five (2 <N <5). This is a com5 promis- sion between the desired weight savings of the CL collection lens according to the invention and technological limitations.

V nadaljnjem prednostnem izvedbenem primeru po izumu vsi zunanji krožni robovi OCE odstopajo od namišljene konveksne ploskve CS za enako višino h.In a further preferred embodiment of the invention, all OCE outer circumferential edges deviate from the imaginary convex plane CS by the same height h.

Vstopna gladka površina SF zbiralne leče CL po izumu je lahko konkavna, konveksna ali ravna. Polmer r ukrivljenosti gladke površine SF, če je le-ta krogelne oblike, pa se določi tako, da se maksimira skozi zbiralno lečo CL prepuščeni svetlobni tok.The inlet smooth surface of the SF collection lens CL according to the invention can be concave, convex or straight. However, the radius r of the curvature of the smooth surface SF, if it is of a spherical shape, is determined by maximizing the light transmission through the collecting lens CL.

Predstavljena zbiralna leča CL ima goriščno razdaljo f. Posamezni odseki površine so natančno izoblikovani tako, da po prehodu skozi zbiralno lečo svetlobni žarki iz gorišča Φ tvorijo vzporeden snop žarkov (sl. 5).The presented CL collection lens has a focal length f. The individual sections of the surface are precisely shaped so that, after passing through the collection lens, the light rays from the focus Φ form a parallel beam of beams (Fig. 5).

Zbiralna leča CL po izumu se izdela iz amorfnega termoplasta ali stekla. Za zbiralno lečo iz amorfnega termoplasta se največja debelina d leče določi tako, daje čas ohlaja( nja ulitka leče s stališča produktivnosti še sprejemljiv.The CL collection lens according to the invention is made of an amorphous thermoplastic or glass. For an amorphous thermoplastic collector lens, the maximum thickness d of the lens is determined so that the cooling time (from a productivity point of view, is still acceptable from a lens point of view).

Oblikovanje zbiralne leče CL po izumu iz amorfnega termoplasta se postopno izvede takole.The design of the CL collection lens of the invention from an amorphous thermoplastic is progressively carried out as follows.

Najprej se glede na čas, ki je potreben za ohladitev ulitka z debelino d, oceni največja, s stališča produktivnosti še sprejemljiva debelina d leče. Ulitek iz amorfnega termoplasta z debelino stene 4 mm se ohlaja 25 sekund. Potreben čas za ohladitev se povečuje približno sorazmerno s kvadratom debeline ulitka: 20 mm debela plankonveksna leča iz amorfnega termoplasta se ohlaja vsaj 600 sekund. Pri plankonveksni leči z debelino do 10 mm lahko pričakujemo čas hlajenja pod 150 sekundami, ob uporabi tem6 periranega kalupa z nihajočo temperaturo pa celo pod 120 sekundami. To že omogoča minimalno sprejemljivo produktivnost pri izdelavi zbiralne leče CL po izumu.First, the maximum thickness, acceptable from the point of view of productivity, of the lens d is considered, given the time required to cool the casting with thickness d. An amorphous thermoplastic mold with a wall thickness of 4 mm is cooled for 25 seconds. The required cooling time increases approximately in proportion to the square of the casting thickness: a 20 mm thick plank-convex lens from an amorphous thermoplastic cools for at least 600 seconds. With a plankonvex lens up to 10 mm thick, a cooling time of less than 150 seconds can be expected, and a tempered mold with a fluctuating temperature of up to 120 seconds can be expected. This already allows for minimal acceptable productivity in the manufacture of the CL collection lens according to the invention.

V naslednjem koraku se pri izbrani debelini d zbiralne leče CL po izumu izbere število N obročastih Fresnelovih zon in s številom N povezana višina h odstopanja zunanjih krožnih robov OCE od namišljene konveksne ploskve CS. Z večanjem števila N pri stalni debelini d se sicer višina h manjša - veča se namreč obosna razdalja med ploskvama SF in CS - in dosežejo se boljše teoretične optične lastnosti leče, toda povečuje se število neostrih zunanjih in notranjih krožnih robov OCE oziroma ICE, na katerih se svetloba lomi iz predvidene smeri. Kot optimalna se izkaže izbira števila N med 2 in 5. Pri manjšem številu Nje večja osrednja lomeča površina CRS in večja je aktivna višina a leče, ki se meri od spodnjega roba leče do vrha osrednje lomeče površine CRS (sl. 5); v projekcijskem žarometu z elipsoidnim reflektorjem Rje namreč s senčnikom S opredeljena svetlo-temna meja zasenčenega svetlobnega pramena (sl. 1), ta pa uporablja le spodnji dve tretjini zbiralne leče.In the next step, at the selected thickness d of the collection lens CL according to the invention, the number of N annular Fresnel zones is selected and the number N associated with the height h is the deviation of the outer circular edges of the OCE from the imaginary convex plane CS. By increasing the number N at a constant thickness d, the height h decreases - the axial distance between the SF and CS surfaces increases - and better theoretical optical properties of the lens are achieved, but the number of sharp outer and inner circular edges of the OCE and ICE at which the light is refracted from the intended direction. The choice of N between 2 and 5 is optimal. For smaller numbers of N, the larger the CRS central breaking surface and the greater the active height a of the lens, which is measured from the bottom edge of the lens to the top of the CRS central breaking surface (Fig. 5); in the projection headlamp with the ellipsoid reflector Rje, namely, with the S shade, the light-dark boundary of the shaded light is defined (Fig. 1), which uses only the lower two thirds of the collection lens.

ii

Nato se izbere polmer r ukrivljenosti gladke lečne površine SF, skozi katero žarki vstopajo v zbiralno lečo CL, in sicer tako da se približno izenačita vstopni kot vsakega žarka v lečo in izstopni kot tega žarka iz leče, s čimer se minimirajo svetlobne izgube zaradi odbojev na vstopni in izstopni površini zbiralne leče. Pri zbiralnih lečah z goriščno razdaljo f pod 50 mm je gladka lečna površina SF konkavna (sl. 2), z goriščno razdaljo med 50 mm in 60 mm je približno ravna (sl. 1) in z goriščno razdaljo nad 60 mm konveksna. Optimalen polmer r ukrivljenosti gladke lečne površine SF se določi z računalniškimi simulacijami po postopku Monte Carlo na komercialnem programskem paketu, pri čemer se upoštevajo optične značilnosti svetlobnega vira LS, elipsoidnega reflektoija R in senčnika S. Zbiralna leča CL po izumu se odlikuje zlasti pri kratkih goriščnih razdaljah in je zato primerna za konstruiranje kratkih žarometov. Zelo je primerna za žaromet za meglo, kije še posebno prostorsko omejen.Then, the radius r of curvature of the smooth lens surface SF through which the rays enter the collecting lens CL is chosen to approximate the angle of inlet of each ray into the lens and the exit angle of that beam from the lens, thereby minimizing light losses due to reflections on the inlet and outlet surfaces of the collection lens. For collection lenses with focal length f below 50 mm, the smooth lens surface SF is concave (Fig. 2), with a focal length between 50 mm and 60 mm approximately flat (Fig. 1) and a focal length above 60 mm convex. The optimal radius r of curvature of the smooth lens surface SF is determined by computer simulations using the Monte Carlo method on a commercial software package, taking into account the optical characteristics of the LS light source, the ellipsoidal reflectance R and the shade S. The CL collection lens is particularly distinguished for short focal points distances and is therefore suitable for constructing short headlamps. It is very suitable for fog lamps, which are especially limited in space.

Fresnelove lomeče površine RRS in CRS se nato natančno izoblikujejo z računskim postopkom za minimiranje sferične aberacije pri debelih lečah. Višine h odstopanja zunanjih krožnih robov OCE od namišljene konveksne ploskve CS šele sedaj dobijo dokončne vrednosti.The Fresnel refractive surfaces of RRS and CRS are then precisely formed by a computational procedure to minimize spherical aberration in thick lenses. The heights of the deviation of the outer circular edges of the OCE from the imaginary convex CS plane are only now getting definitive values.

Za izdelavo zbiralne leče CL po izumu so primerni prozorni amorfni termoplasti iz skupine polimetil metakrilimidov, na primer PLEXIMID 8805, izjemoma za projekcijski žaromet s halogenskim svetlobnim virom za meglo, kjer se modra svetloba lahko odfiltrira že pred zbiralno lečo, da se izogne Rayleighovemu sipanju modre svetlobe na delcih megle, pa tudi iz skupine polikarbonatnih kopolimerov, na primer APEC 9359/7. Prednost drugih je v šibkejši absorpciji v infrardečem področju, prednost prvih pa predvsem v majhni odvisnosti lomnega količnika od valovne dolžine svetlobe v vidnem področju.For the manufacture of the CL collection lens according to the invention, transparent amorphous thermoplastics of the polymethyl methacrylimide group, for example PLEXIMID 8805, are exceptionally suitable for a projection headlamp with a halogen fog light source, where blue light can be filtered out before the collection lens to avoid Rayleigh scattering of fog particles as well as polycarbonate copolymers such as APEC 9359/7. The advantage of the latter is the weaker absorption in the infrared region, and the advantage of the former is primarily the small dependence of the refractive index on the wavelength of light in the visible field.

Zbiralna leča CL po izumu pa se na osnovi opisane geometrije lahko izdela tudi iz steklenih materialov. Dosežejo se opisani koristni optični učinki in prihranek na masi.The CL collection lens according to the invention can also be made of glass materials based on the geometry described. The described beneficial optical effects and mass savings are achieved.

V priloženi tabeli so zbrani rezultati računskih simulacij za pet zbiralnih leč - primera 5 in 6 se nanašata na zbiralno lečo CL po izumu - z goriščno razdaljo f = 25 mm in premerom leče 50 mm v projekcijskem žarometu z žarnico HI 1 s svetilnostjo 1.000 lm kot svetlobnim virom in aluminiziranim elipsoidnim reflektoijem, ki je prirejen za rabo v žarometu za meglo z ravno svetlo-temno mejo. Simulacija za posamezen primer je zajela 2.000.000 iz žarnice izstopajočih žarkov in jih je spremljala pri odbojih in lomih do izstopa iz zbiralne leče.The accompanying table summarizes the results of computational simulations for five collection lenses - Examples 5 and 6 refer to the collection lens CL of the invention - with a focal length f = 25 mm and a lens diameter of 50 mm in a projection headlamp with a HI 1 lamp with a luminous intensity of 1,000 lm. a light source and an aluminized ellipsoid reflector adapted for use in a front fog lamp with a flat light-dark boundary. The case-by-case simulation captured 2,000,000 from the bulb of protruding rays and monitored them in reflections and refractions until they exited the collecting lens.

Primera 1 in 2 se nanašata na stekleno oziroma termoplastno klasično zbiralno lečo.Examples 1 and 2 refer to a glass or thermoplastic classic collection lens.

Primer 3 se nanaša na termoplastno klasično zbiralno lečo, ki pa ima konkavno vstopno površino, kar se ugodno odrazi na večji svetlobni prepustnosti leče.Example 3 relates to a thermoplastic classic collecting lens, which has a concave inlet surface, which is advantageously reflected in the greater light transmission of the lens.

Primer 4 se nanaša na Fresnelovo lečo po stanju tehnike. Ta leča izkazuje velik prihranek na masi, vendar ima nizko svetlobno prepustnost in močno blešči.Example 4 relates to a Fresnel lens according to the prior art. This lens shows great mass savings, but has low light transmittance and shines brightly.

Primer št. Example no. 1 1 2 2 3 3 4 4 5 5 6 6 Slika Image 1 1 1 1 2 2 3 3 4 4 4 4 Material Material steklo glass Apec 9359/7 Apec 9359/7 Apec 9359/7 Apec 9359/7 Apec 9359/7 Apec 9359/7 Apec 9359/7 Apec 9359/7 Apec 9359/7 Apec 9359/7 Gorišč. razd. f Attics. diff. f 25 mm 25 mm 25 mm 25 mm 25 mm 25 mm 25 mm 25 mm 25 mm 25 mm 25 mm 25 mm Debelina d Thickness d 20,3 mm 20,3 mm 19,3 mm 19,3 mm 19,9 mm 19,9 mm 2 mm 2 mm 9,7 mm 9,7 mm 8,8 mm 8,8 mm Masa leče The mass of the lens 57,3 g 57,3 g 27 g 27 y 27 g 27 y 4g 4g 14 g 14 y 13 g 13 y Celoten prepuščeni svetlobni tok Total transmitted light output 255,4 lm 255,4 lm 254,7 lm 254.7 lm 255,3 lm 255,3 lm 217,7 lm 217.7 lm 236,7 lm 236.7 lm 235,0 lm 235,0 lm Doseženi vrh osvetljenosti Brightness peak reached 7,3 lx 7,3 lx 7,2 lx 7,2 lx 7,4 lx 7,4 lx 4,9 lx 4,9 lx 6,1 lx 6,1 lx 5,9 lx 5,9 lx Bleščanje v zoni HV* nad sv.-t. mejo Glitter in HV * zone above sv.-t. the border < 0,007 lx <0.007 lx < 0,007 lx <0.007 lx < 0,007 lx <0.007 lx 0,1 lx 0,1 lx 0,03 lx 0,03 lx 0,04 lx 0,04 lx r r oo oo cc cc 200 mm 200 mm 00 00 100 mm 100 mm 100 mm 100 mm r' r ' 37 mm 37 mm 41 mm 41 mm h h 1 mm 1 mm 2,68 mm 2,68 mm 2,78 mm 2.78 mm N N 0 0 0 0 0 0 15 15 3 3 3 3

* po ECE normi* according to ECE standard

Primera 5 in 6 se nanašata na zbiralno lečo CL po izumu (sl. 4 in 5). Glede na Fresnelovo lečo iz primeru 4 zbiralna leča CL po izumu izkazuje višjo svetlobno prepustnost in manj blešči. To seje doseglo z zmanjšanjem površine in števila neugodnih površin, kot so obročaste površine RS S skoka in površine zaobljenih zunanjih in notranjih krožnih robov OCE oziroma ICE. Glede na klasično zbiralno lečo po primerih 2 in 3 pa ima zbiralna leča po izumu okoli 50 % prihranka na masi.Examples 5 and 6 refer to the collection lens CL of the invention (Figures 4 and 5). According to the Fresnel lens of Example 4, the CL collection lens according to the invention exhibits higher light transmittance and less glare. This session was achieved by reducing the surface area and the number of unfavorable surfaces such as the RS S jump ring surfaces and the surfaces of the rounded outer and inner circular edges of OCE and ICE respectively. According to the classic collection lens according to Examples 2 and 3, however, the collection lens according to the invention has about 50% mass savings.

Claims

Patent claims

1. A collection lens (CL) for a projection headlamp in a road vehicle whose body is bounded on the inlet side by a smooth lens surface (SF) and on the outlet face by a lens surface (FZF) with Fresnel zones, the Fresnel zone being made by an annular or a central breaking surface (RRS, CRS) and an annular surface (RS S) of jump, characterized in that each inner circular edge (ICE) through which the annular breaking surface (RRS) and the adjacent annular surface (RSS) interact ) of the jump, lies on an imaginary convex plane (CS) including the circumferential edge (PE) of the collecting lens (CL) and protruding toward the lens surface (FZF) with Fresnel zones, and that the heights (h) measured in the direction parallel to the geometric axis of the collecting lens (CF), the deviations of the outer circular edges (OCE) from the imaginary convex plane (CS) as small as possible.

Collecting lens (CL) according to claim 1, characterized in that the lens surface (FZF) with Fresnel zones is made with a small number of N annular breaking surfaces (RRS), so that 2 <N <5.

Collecting lens (CF) according to claim 1 or 2, characterized in that all outer circular edges (OCE) deviate from the imaginary convex surface (CS) by the same height (h) measured parallel to the geometric axis of the collecting lens (CL) .

Collection lens (CL) according to one of Claims 1 to 3, characterized in that the smooth lens surface (SF) is concave.

Collecting lens (CF) according to one of Claims 1 to 3, characterized in that the smooth lens surface (SF) is convex.

Collection lens (CL) according to one of Claims 1 to 3, characterized in that the smooth lens surface (SF) is flat.

Collecting lens (CL) according to one of Claims 4 to 6, characterized in that the curvature of the smooth lens surface (SF) is determined by maximizing the light transmission through the collecting lens (CL).

Collection lens (CL) according to one of the preceding claims, characterized in that it is made of an amorphous thermoplastic.

Vehicle headlamp assembly (CL) according to claim 8, characterized in that its maximum thickness (d) is determined by the cooling time of the casting of the lens, which is still acceptable from a productivity standpoint.

Vehicle headlamp assembly (CL) according to claim 8 or 9, characterized in that j

is made of polymethyl methacrylimide.

Vehicle headlamp assembly (CL) according to claim 8 or 9, characterized in that it is made of a polycarbonate copolymer.

Collecting lens (CL) according to one of Claims 1 to 7, characterized in that it is made of glass.

Collection lens (CL) according to any one of the preceding claims, characterized in that the imaginary convex surface (CS) is a spherical surface.