GB2069121A - A main headlamp for motor vehicles - Google Patents

Abstract

The lens (10) of a headlamp for the combined main beam and asymmetric dipped beam has a sector (12) which refracts the incident light rays downwards and towards the vertical central plane (18). A region (21) which has no or only slight optical effect is arranged below the sector (12). <IMAGE>

Description

SPECIFICATION A main headlamp for motor vehicles State of the Art The sector known as a wedge on the lenses of motor vehicle headlamps for the usual main and dipped beam bends the light rays directed upwardly inclined above the horizontal central plane downwards and within the narrow angle from the outer edge of the road to the centre of the road. In so doing, the quality of the dipped beam is improved especially during right-hand turns.

So that dipped beam rays do not fall on the horizontally dispersing lenses below the sector, the sector must extend downwards to a sufficient extent. Were this not the case then glare would prevail.

Since the main beam is also influenced optically by the sector in a similar manner, that is to say the light rays are refracted towards the centre and downwards it produces a greater uniformity of illumination of the road ahead whereby the quality of the main beam is impaired.

Advantages of the Invention The quality of the main beam is improved with the headlamp for motor vehicles according to the invention without the existence of rays causing glare on dipped beam. The portion of the direct rays of the dipped beam falling on the region assists in providing the dipped beam in a predetermined manner and the portion of the direct rays of the main beam falling on the region improves the main beam because these rays fall further forwards Advantageous further developments of the invention are described in the sub-claims. With the construction of headlamp according to claim 2, the lens is released from the pressing tool after the pressing operation.

Drawing An embodiment of Tha invention is illustrated in the drawing and is described in detail in the following specification. The single figure shows the inside view of a lens of a motor vehicle headlamp for the combined asymmetrical dipped beam and main beam to a smailer scale.

Description of the Embodiment The single figure shows a circular lens 10 of a motor vehicle headlamp for the combined full beam and asymmetric dipped beam, comprising an external rim 1 1, a sector 12 with prisms wedge-shaped in cross-section, an inner area 1 3 and an annular area 14 both of which have horizontally dispersing lenses. The lens 10 covers the outlet of a reflector lying in front of the plane of the drawing which has a main beam hot filament at its focal point and in addition has a hot filament for the asymmetrical dipped beam defocused with respect thereto.

The sector 12 extends in a horizontal direction substantially between the centre of the lens and the edge 11 of the lens facing the on-coming traffic and in a horizontal direction between a parallel 1 5 extending slightly above the horizontal central plane 1 6 and a line 1 7 which, proceeding from the vertical central plane 1 8 below the HV point 19, extends substantially at 1 50 with a downward inclination with respect to the edge 11.

The prisms of the sector 1 2 deflect the incident dipped beam rays downwards and in a narrow angle from the outer edge of the road towards the centre of the road; thereby, dazzling of the oncoming traffic, chiefly during right-hand turns, is prevented and the light on the centre of the road is intensified.

A region 21 has substantially the form of a rectangle which is bounded by the line 17, a line 20 parallel thereto, the edge 11 and the vertical central plane 1 8. The line 20 can also extend in a divergent manner with respect to the line 1 7 towards the edge 11 so that the region 21 is trapezoidal. This is either optically ineffective or has ribs 22 (not shown) with only a slight optical effect.

With the dipped beam hot filament switched in, the direct light beam from the lenses of the upper half of the lens is dispersed substantially horizontal, is dispersed downwardly by the prisms of the sector 12 and deflected towards the horizontal central plane 1 8 and the portion of the beam falling on the region 21 passes through the latter substantially un-refracted. With the main beam hot filament switched in, the direct light beam is dispersed by the lenses of the areas 13 and 14 in a horizontal direction, is dispersed by the sector 12 in the above-described manner and is refracted towards the vertical central plane and that portion of the main beam which falls on the region 21 passes therethrough substantially unrefracted.

1. A headlamp for motor vehicles comprising the features: a) a reflector has a hot filament for the main beam at the focal point and a hot filament arranged out of focus for the asymmetrical dipped beam, b) a lens covering the outlet from the reflector has a sector-like section provided with light deflecting means, the section - extends substantially between the vertical central plane and the edge of the lens facing the on-coming traffic and - lies mainly below the horizontal central plane of the lens, c) the lower region of the sector-like section has no or only slight optical effect.

2. A headlamp according to claim 1 comprising the feature: d) the region has moulded ribs which are substantially opticaliy ineffective.

3. A headlamp according to claim 1 or 2 with the following feature: e) the region is formed sector-like.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A main headlamp for motor vehicles State of the Art The sector known as a wedge on the lenses of motor vehicle headlamps for the usual main and dipped beam bends the light rays directed upwardly inclined above the horizontal central plane downwards and within the narrow angle from the outer edge of the road to the centre of the road. In so doing, the quality of the dipped beam is improved especially during right-hand turns. So that dipped beam rays do not fall on the horizontally dispersing lenses below the sector, the sector must extend downwards to a sufficient extent. Were this not the case then glare would prevail. Since the main beam is also influenced optically by the sector in a similar manner, that is to say the light rays are refracted towards the centre and downwards it produces a greater uniformity of illumination of the road ahead whereby the quality of the main beam is impaired. Advantages of the Invention The quality of the main beam is improved with the headlamp for motor vehicles according to the invention without the existence of rays causing glare on dipped beam. The portion of the direct rays of the dipped beam falling on the region assists in providing the dipped beam in a predetermined manner and the portion of the direct rays of the main beam falling on the region improves the main beam because these rays fall further forwards Advantageous further developments of the invention are described in the sub-claims. With the construction of headlamp according to claim 2, the lens is released from the pressing tool after the pressing operation. Drawing An embodiment of Tha invention is illustrated in the drawing and is described in detail in the following specification. The single figure shows the inside view of a lens of a motor vehicle headlamp for the combined asymmetrical dipped beam and main beam to a smailer scale. Description of the Embodiment The single figure shows a circular lens 10 of a motor vehicle headlamp for the combined full beam and asymmetric dipped beam, comprising an external rim 1 1, a sector 12 with prisms wedge-shaped in cross-section, an inner area 1 3 and an annular area 14 both of which have horizontally dispersing lenses. The lens 10 covers the outlet of a reflector lying in front of the plane of the drawing which has a main beam hot filament at its focal point and in addition has a hot filament for the asymmetrical dipped beam defocused with respect thereto. The sector 12 extends in a horizontal direction substantially between the centre of the lens and the edge 11 of the lens facing the on-coming traffic and in a horizontal direction between a parallel 1 5 extending slightly above the horizontal central plane 1 6 and a line 1 7 which, proceeding from the vertical central plane 1 8 below the HV point 19, extends substantially at 1 50 with a downward inclination with respect to the edge 11. The prisms of the sector 1 2 deflect the incident dipped beam rays downwards and in a narrow angle from the outer edge of the road towards the centre of the road; thereby, dazzling of the oncoming traffic, chiefly during right-hand turns, is prevented and the light on the centre of the road is intensified. A region 21 has substantially the form of a rectangle which is bounded by the line 17, a line 20 parallel thereto, the edge 11 and the vertical central plane 1 8. The line 20 can also extend in a divergent manner with respect to the line 1 7 towards the edge 11 so that the region 21 is trapezoidal. This is either optically ineffective or has ribs 22 (not shown) with only a slight optical effect. With the dipped beam hot filament switched in, the direct light beam from the lenses of the upper half of the lens is dispersed substantially horizontal, is dispersed downwardly by the prisms of the sector 12 and deflected towards the horizontal central plane 1 8 and the portion of the beam falling on the region 21 passes through the latter substantially un-refracted. With the main beam hot filament switched in, the direct light beam is dispersed by the lenses of the areas 13 and 14 in a horizontal direction, is dispersed by the sector 12 in the above-described manner and is refracted towards the vertical central plane and that portion of the main beam which falls on the region 21 passes therethrough substantially unrefracted. CLAIMS

1. A headlamp for motor vehicles comprising the features: a) a reflector has a hot filament for the main beam at the focal point and a hot filament arranged out of focus for the asymmetrical dipped beam, b) a lens covering the outlet from the reflector has a sector-like section provided with light deflecting means, the section - extends substantially between the vertical central plane and the edge of the lens facing the on-coming traffic and - lies mainly below the horizontal central plane of the lens, c) the lower region of the sector-like section has no or only slight optical effect.

2. A headlamp according to claim 1 comprising the feature: d) the region has moulded ribs which are substantially opticaliy ineffective.

3. A headlamp according to claim 1 or 2 with the following feature: e) the region is formed sector-like.

4. A headlamp according to claim 1 or 2 with the following feature: f) the region is made strip-like.

5. A headlamp for motor vehicles substantially as herein described with reference to the accompanying drawing.