This invention relates to fog light systems, systems, vehicles and control systems.

There is a general need for improved viewing systems which are able to operate well in conditions of poor visibility associated with fog. The present invention addresses this need. Although the invention is not limited to the field of automobiles, in one aspect the invention addresses a particular problem associated with automobiles. It would be desirable to provide a fog light system which overcomes problems associated with reflection from fog and which is compatible with anti-dazzle systems used with automobile headlights. However, the anti-dazzle headlight systems which have been proposed and which overcome problems caused by road camber and uneven road surfaces utilise circularly polarised light. It has been found that circularly polarised light does not assist in overcoming the problems associated with reflection from fog. Therefore, existing systems are incompatible.

According to a broad first aspect of the invention there is provided a fog light and viewing means associated with the fog light;

in which the fog light has a linear or elliptical polariser attached or incorporated therein having an associated plane of polarisation or handedness so that the fog light projects light of a defined polarisation, and the viewing means includes a linear or elliptical polariser having an associated plane of polarisation or handedness which is oriented so that light from the fog light which is incident on the viewing means after being reflected from water droplets in a fog is substantially blocked.

The fog light polariser may be a linear polariser having an associated plane of polarisation. The viewing means polariser may be a linear polariser having an associated plane of polarisation which is orthogonal to the plane of polarisation of the fog light polariser.

The fog light polariser may be an elliptical polariser having an associated handedness. The viewing means polariser may be an elliptical polariser having an associated handedness which is opposite to the handedness of the fog light polariser. This arrangement is particularly useful with automobiles because it ameliorates problems associated with intense dazzle from oncoming automobiles in the event of a road camber or an uneven driving surface.

The fog light polariser may transmit light of a defined elliptical polarisation resolvable into a major linearly polarised component which is polarised in a first plane and a minor linearly polarised component which is polarised in a second plane orthogonal to the first plane. The viewing means may comprise a linear or elliptical polariser which blocks light incident on the viewing means which is linearly polarised in the first plane. This arrangement can be advantageous with automobiles. It can enable automobiles to use a common and compatible headlight and fog light system. The polariser of the viewing means may be a linear polariser having an associated plane of polarisation which is orthogonal to the first plane. Alternatively, the polariser of the viewing means may be an elliptical polariser having an associated handedness which is opposite a handedness associated with the elliptical polariser of the fog light.

The defined elliptical polarisation of headlight polariser may comprise an associated preferential axis. The preferential axis may be less than 20° from the major linearly polarised component, preferably less than 15°, more preferably in the range 5° to 10°.

The light of a defined polarisation projected by the fog light may be visible light and/or infra-red (IR) light.

The viewing means may comprise an image processor for enhancing or otherwise processing an image obtained using the viewing means.

The viewing means may be attached to the fog light. The fog light may project light generally along a first axis. The viewing means may be attached to the fog light in a fixed orientation so that light propagating along an axis which is parallel to the first axis is incident normal to the polariser of the viewing means.

The fog light system may be associated with or intended to be used in conjunction with a structure such as a vehicle. The system may be moveable independently of any direction of motion of the structure to project light over a range of directions.

The fog light system may be a handheld device such as a torch.

The fog light system may be a spotlight device.

The fog light system may be binocular, monocular, telescope device, aiming device or ranging device such as a rifle scope. The fog light system may be a camera, such as a CCTV camera, other surveillance device, or a broadcast TV camera, or a sensor.

The fog light system may be a helmet having the fog light and the viewing means.

The fog light may comprise a laser. The fog light may comprise any other suitable light source, such as a LED light source.

The viewing means may be a screen, an eyepiece, a visor, spectacles, goggles, and/or includes at least one lens.

The fog light polariser may provide a polarising effect over a first frequency bandwidth and the viewing means polariser may provide a polarising effect over a second frequency bandwidth, wherein the first and second frequency bandwidths at least partially overlap, and preferably overlap completely.

The fog light may prevent light having a frequency outside of the first frequency bandwidth from being projected.

The viewing means may be responsive to light incident thereon having a frequency outside of the second frequency bandwidth thereby enhancing the viewing of ambient light.

Alternatively, the viewing means may not be responsive to light incident thereon having a frequency outside of the second frequency bandwidth.

At least one of the fog light polariser and the viewing means polariser may i) provide a polarising effect over a frequency bandwidth which is a subset of the visible spectrum, and ii) transmit visible light which is not within the frequency bandwidth thereby enhancing the viewing of ambient light. The viewing means may comprise a wave plate element positioned behind the linear or elliptical polariser of the viewing means.

The fog light may be fitted with a polariser oriented such that linear or elliptical polarised light is emitted in a particular plane or preferential axis (the plane of polarisation). Typically the plane of polarisation is vertical. In the case of an elliptical polariser the preferential axis may be the main axis.

In one embodiment the effective frequency bandwidth of the fog light and/or the fog light polariser and/or the viewing means polariser may be a defined narrow bandwidth within but not limited to the visible and infrared regions of the electromagnetic spectrum. In the case of the viewing means this allows a greater transmittance of ambient (unpolarised light).

The viewing means may be fitted with a polarising analyser oriented such that polarised light emitted from the light source, when reflected by the water droplets in fog, is blocked by the analyser in the viewing system.

In a further embodiment the viewing means may be fitted with a wave plate or other anisotropic material oriented on the inside (i.e., viewing side) of the viewing means to mitigate any effects of wearing polarised sunglasses (i.e., there would be two wave plates if using a rotating polarising analyser).

The system may be: a) a handheld device; b) fitted to a hull, airframe, vehicle body or any other structure; c) supplied as a helmet comprising a light source and a visor; d) incorporated into a binocular, monocular or telescope; e) incorporated into a mounted device including, but not limited to, CCTV and other surveillance devices; f) extended to include the Infrared range to be incorporated into IR CCTV and other thermal imaging systems; and/or g) extended to include laser light sources

The system will also find utility in many sectors including but not limited to civilian, and aerospace.

According to a second aspect of the invention there is provided a vehicle such as a ship, aircraft or automobile, having a fog light system according to the first aspect of the invention attached thereto or incorporated therein.

The vehicle may further comprise an automated control system for controlling the vehicle, in which the viewing means of the fog light system provides a data input into the automated control system.

The automated control system may be a fully automated control system for driving the vehicle.

Alternatively, the automated control system may be a driver assistance system, such as an emergency braking system.

According to a third aspect of the invention there is provided an automated control system comprising a fog light system according to the first aspect of the invention.

The automated control system may control a vehicle or a robotic device.

According to a fourth aspect of the invention there is provided a vehicle comprising:

at least one headlight having an elliptical polariser attached or incorporated therein which transmits light of a defined elliptical polarisation resolvable into a major linearly polarised component which is polarised in a first plane and a minor linearly polarised component which is polarised in a second plane orthogonal to the first plane;

viewing means comprising a linear or elliptical polariser which blocks light incident on the viewing means which is linearly polarised in the first plane; and at least one fog light having a polariser attached to or incorporated therein so that the fog light projects polarised light, wherein said polariser is either a linear polariser which transmits light polarised in the first plane, or an elliptical polariser which transmits light of a defined elliptical polarisation resolvable into a major linearly polarised component which is polarised in the first plane and a minor linearly polarised component which is polarised in the second plane.

The polariser of the viewing means may be a linear polariser having an associated plane of polarisation which is orthogonal to the first plane.

Alternatively, the polariser of the viewing means may be an elliptical polariser having an associated handedness which is opposite a handedness associated with the elliptical polariser of the headlight and/or the fog light.

The viewing means may be a windscreen.

The defined elliptical polarisation of the elliptical polariser of the headlight and, optionally, one or both of the viewing means polariser and the fog light polariser may comprise an associated preferential axis, and the preferential axis may be less than 20° from the major linearly polarised component, preferably less than 15°, more preferably in the range 5° to 10°.

According to a fifth aspect of the invention there is provided a vehicle comprising: at least one headlight having an elliptical polariser attached or incorporated therein which transmits light of a defined elliptical polarisation resolvable into a major linearly polarised component which is polarised in a first plane and a minor linearly polarised component which is polarised in a second plane orthogonal to the first plane;

viewing means including a linear polariser which substantially blocks light incident on the viewing means which is linearly polarised in the first plane; and at least one fog light having a linear polariser attached or incorporated therein so that the fog light projects linearly polarised light, wherein the linear polariser is oriented so that linearly polarised light from the fog light which is incident on the viewing means after being reflected from water droplets in a fog is substantially blocked by the polariser of the viewing means.

The viewing means may be a windscreen.

The defined elliptical polarisation of the elliptical polariser of the headlight and, optionally, one or both of the viewing means polariser and the fog light polariser may comprise an associated preferential axis, and the preferential axis may be less than 20° from the major linearly polarised component, preferably less than 15°, more preferably in the range 5° to 10°.

According to a sixth aspect of the invention there is provided an IR imaging system including;

an IR imaging device having a circular or elliptical IR polariser attached to or incorporated therein which transmits IR light of a defined handedness incident thereon with a first efficiency, and transmits light of the opposite handedness incident thereon with a second efficiency, in which the second efficiency is substantially lower than the first efficiency; and

a vehicle having at least one headlight and/or IR projection device having a circular or elliptical IR polariser attached to or incorporated therein so that the headlight and/or the IR projection device outputs IR light of the opposite handedness.

In this way, problems related to IR 'dazzle' associated with IR night vision imaging systems can be reduced or alleviated. The IR 'dazzle' may be caused by IR light from oncoming headlights and/or IR light from IR projection devices on oncoming vehicles.

The second efficiency may be 0% or close to 0%.

The IR polarisers may be of a type described in my co-pending UK patent application 1319420.4 and International patent application WO2014/122424.

Typically, the IR imaging device comprises part of the vehicle itself. However, in principle, the IR imaging device may be differently provided, for example as a visor, spectacles, or other device worn by an occupant of the vehicle.

Generally, the circular or elliptical IR polarisers each include an IR retarder and an IR linear polariser.

Whilst the invention has been described above, it extends to any inventive combination of the features set out above, or in the following description, drawings or claims.

Embodiments of systems in accordance with the invention will now be described with reference to the accompanying drawings, in which:- Figure 1 shows (a) the general principles of an anti-fog dazzle system of the invention and (b) the general principles of a "near-linear elliptical" polarisation anti-fog dazzle system suitable for automobiles;

Figure 2 shows (a) a handheld device incorporating an opto-electronic system;

Figure 3 shows a spotlight device;

Figure 4 shows a CCTV device;

Figure 5 shows a safety helmet;

Figure 6 shows a selective band pass polariser system;

Figure 7 shows a near-linear elliptical polarisation state suitable for use with a combined fog light/headlight anti-dazzle system in a vehicle;

Figure 8 shows a narrow band pass filter system to reduce the effect of noise from external light sources;

Figure 9 shows spectral intensity for images obtained (a) without and (b) with a fog light system of the invention (c) with an image processing step (d) with a further image processing step and (e) with a final imaging processing step; and

Figure 10 is a schematic diagram of an automated vehicle.

Figure 1 (a) shows a first general embodiment of the invention which uses linearly polarised light. Figure 1 (a) shows a fog light system, depicted generally at 10, which comprises a fog light source 12 which produces light 14. In the embodiment shown in Figure 1 (a), the light 14 is unpolarised. The unpolarised light 14 passes through a polariser arrangement which comprises a light transmitting structure 16 formed from glass or another suitable isotropic material and a linear polariser 18. The linear polariser 18 ensures that light 20 emanating from the fog light is preferentially polarised in a desired plane. In the system shown in Figure 1 (a), by way of example only, the light 20 is vertically polarised. Some of the light 20 emanating from the fog light is subsequently reflected. Light 22 reflected from objects is usually substantially unpolarised. In contrast, when any linearly polarised light is reflected from water droplets in fog, the reflected light retains the linear polarisation state. In the example shown in Figure 1 (a), the vertically polarised light 20 is reflected from water droplets in fog as vertically polarised light 24. The fog light system further comprises a viewing device for preferentially viewing light reflected from objects and rejecting light reflected from water droplets in fog which would otherwise appear as a dazzling light. The viewing device comprises a polariser 26, a structure 30 formed from glass or another suitable isotropic material, and, optionally, a ¼ wave retarder 28. In this way, unpolarised ambient light (including light reflected from objects) can be passed by the viewing device (as polarised light). In contrast, the light 24 reflected from water droplets in fog is substantially blocked. Approximately 99% of the horizontally polarised light can be routinely blocked using this arrangement. The optional ¼ wave retarder 28 may be provided to prevent orthogonal interaction with polarised sunglasses used by a viewer of the fog light system. The polarisers 18, 26 may be provided as an interlayer or an outer layer of the fog light and viewing device. As described in more detail below, viewing enhancement and image processing systems may be provided to process the images obtained using the present invention. Figure 1 (b) shows a second general embodiment of the invention which uses elliptically polarised light. Figure 1 (b) shows a fog light system depicted generally at 34, which comprises a fog light source 36 which produces unpolarised light 38. The unpolarised light 38 passes through a structure 40 formed of glass or another suitable isotropic material and then passes through an elliptical polariser arrangement which comprises a linear polarising element 42 and an elliptical retarder element 44. In this way, the fog light system produces elliptically polarised light 46. Some of the light 46 is subsequently reflected. Light reflected from objects is generally unpolarised in nature. When the elliptically polarised light 46 is reflected from water droplets in fog, elliptical polarisation is generally retained. The fog light system 34 further comprises a viewing device. The viewing device comprises an elliptical polariser which is made up of an elliptical retarder element 52 and a linear polariser element 54. The viewing device further comprises an optional ¼ wave retarder 56 and a structure 58 formed from glass or another suitable isotropic material. The elliptical polariser formed from the elliptical retarder element 52 and the linear polariser element 54 are configured to block the polarisation state associated with the light 50 reflected from water droplets in fog. In this way, approximately 99% of the light 50 reflected from water droplets in fog can be routinely blocked. In contrast, ambient light 60, which includes light emanating from the fog light which has reflected from objects, is allowed to pass through the fog light system for viewing purposes. It will be appreciated that the ambient light is passed through the viewing device as polarised light. The polarising elements of the fog light system 34 may be provided as an interlayer or an outer layer. Figures 2 to 5 shows embodiments of the invention which use the general principles designed with reference to Figures 1 (a) and 1 (b).

Figure 2 shows a handheld fog light device 70. The device 70 comprises a main body 72 having a handgrip 74 attached thereto. Main body 72 houses a fog light source (not shown) and a polariser 76. The polariser 76 is configured so that the device 70 produces a polarised light output 78. The polarised light output may be either linearly or elliptically polarised. Some of the polarised light 78 produced by fog light device 70 is reflected and returns to the fog light device 70 as reflected light 80. The reflected light 80 is recorded by a camera 84. The reflected light 80 passes into the camera 84 through a polariser 82. The polariser 82 is selected so that it optimally blocks the linear or elliptically polarisation state associated with light 78. The images in the camera 84 are processed using an image processor 86. Processed images can be viewed by the user on a display 88. The handheld device 70 is an opto-electronic device. It is also possible to provide a handheld optical fog light device which does not utilise a camera and image processor.

Figure 3 shows a mounted fog light system, depicted generally at 90. The mounted fog light system comprises a main body 92 which is attached to a support 94 which may be a tripod or another suitable structure. The main body 92 may be moveably mounted on the support 94 such as via a pivoting arrangement. The main body 92 comprises a fog light source (not shown) and a polariser 96. The polariser 96 may be a linear or elliptical polariser so that the device 90 produces polarised light 98. A proportion of the light 98 is reflected as light 100. The light 100 is received by a viewing system 102. The viewing system 102 includes a polariser (not shown). The configurations of the polariser 96 and the polariser of the viewing system 102 are such that the polarised component of the reflected light 100 which has been reflected off water droplets in fog is substantially blocked by the polariser of the viewing system 102. The skilled reader will appreciate that the mounted fog light device 90 can be implemented in a number of forms. For example, the device 90 can be provided as a spotlight device. Additionally, or alternatively, the mounted device may be mounted to a fixed structure, such as a building, or a moving structure, such as a land vehicle or a ship.

Figure 4 shows an anti-fog camera device, depicted generally at 1 10. The camera device 1 10 is mounted to a structure such as a wall 1 12 via an attachment structure 1 16. The camera 1 10 may be moveable, and the movement may be controllable remotely. The camera 1 10 comprises a main camera body 1 14 which is attached to the attachment structure 1 16. The main body 1 14 has a fog light source 1 18 mounted on a lower surface thereof. The light source 1 18 has a linear or elliptical polariser 120 attached to it so that the fog light source 1 18 produces linearly or elliptically polarised light 122. A component 124 of the polarised light 122 is reflected. The reflected light 124 is detected by a camera which is housed in the main camera body 1 14. The reflected light 124 enters the camera through a linear or elliptical polariser 126. The configurations of the polarisers 120 and 126 are such that any component of the light 124 which has been reflected from water droplets in fog is substantially blocked by the polariser 126. The camera 1 10 further comprises an image processor 128. The anti-fog device 1 10 can be provided as a CCTV system or as another type of camera device. Devices which are configured to act as sensors are also possible.

Figure 5 shows a helmet-based fog light system 130 comprising a helmet 132 and a fog light projector 134 which includes a fog light source (not shown). A linear or elliptical polariser 136 is positioned over the light emitting portion of the fog light projector 134 so that the fog light projector 134 produces linearly or elliptically polarised light 138. The helmet 132 has a visor 142 which is configured to be in the eye line of a wearer of the helmet 132. Some of the light 138 projected by the device 130 may return as reflected light 140. The visor 142 comprises a linear or elliptical polariser (not shown). The configurations of the polariser 136 and the polariser of the visor are selected so that any component of the reflected light 140 which has been reflected from water droplets in fog is substantially blocked by the polariser of the visor 142. It is possible to provide an opto-electronic version of a wearable device such as a helmet. In these embodiments, an assisted vision viewing device is provided which may comprise image enhancements and/or image processing capabilities and a suitable display. The assisted vision viewing device may be provided as a visor or as goggles.

The invention provides significantly improved viewing and/or image detection in fog. Results may be further enhanced with image processing. Figure 9 shows improvements obtained using image collection and processing of the invention. Figure 9(a) shows spectral data obtained in fog without using the dazzle reduction techniques of the invention. High levels of white energy from light which is reflected from the fog are evident. This high white energy content significantly suppresses the target image data. Figure 9(b) shows spectral data after a "first pass" in which a polariser based system of the invention is used. Fog reflection data are removed, and the basic target image data are now evident. Figure 9(c) shows spectral data obtained after a "second pass" in which software is used to perform image processing. The target image data now have an associated range of frequencies which are more dynamically centred. Figure 9(d) shows spectral data obtained after a "third pass" using a further software processing step. Data which are not associated with the real image have now been discarded. Figure 9(e) shows spectral data obtained after a "fourth pass" using a further software processing step. The contrast ratio and dynamic range are now increased to produce a final enhanced image.

The invention also provides autonomous and semi-autonomous vehicles which utilise images obtained using fog light systems of the type described herein. Autonomous vehicles use a number of techniques to sense their surroundings. Techniques such as radar, lidar, GPS and computer vision may be used. Examples of autonomous vehicle systems can be found in US8139109 and US2012/0083960, the entire contents of both of which are herein incorporated by reference. Another system developed by Toyota uses a forward facing camera and a millimetre wave radar to input into to a system which then controls the vehicle steering to keep the vehicle in lane. Figure 10 is a schematic diagram of an autonomous vehicle 200. The vehicle 200 comprises a control device 202, typically a computer, which controls a vehicle steering system 204 in response to input data received from a sensing system 206. For simplicity of presentation, the sensing system 206 is shown as a single feature in Figure 10. However, in practice, the sensing system may comprise a number of separate components, such as described above. The vehicle 200 further comprises fog lights 208 in accordance with the invention having linear or elliptical polarisers. The vehicle 200 further comprises a camera 210 which is also in accordance with the invention, i.e., the camera 210 is also provided with a linear or elliptical polariser which is configured to substantially reject light from the fog lights 208 which is reflected by fog. The images obtained by the camera 210 are input into the control device 202. In this way, an autonomous driving system is provided which has improved capability to perform in foggy conditions. It will be appreciated that the control device 202 may provide autonomous control of other driving functions in addition to the steering of the vehicle. Semi-autonomous vehicles might also be provided.

The wavelengths of the polarised light emitted by the fog light and the incoming light accepted by the viewing system may be selected, such as through use of band pass filters. Figure 6 shows one embodiment using a selective bandwidth. Figure 6(a) shows the spectral output of a white LED which may be used in a fog light system of the invention. In this embodiment, a band pass polariser is used so that only polarised light in the bandwidth 150 is emitted from the fog light. Therefore, in the fog light, light of wavelengths outside of the bandwidth 150 are blocked. A band pass polariser is used in connection with the viewing device so that (Figure 6(b)) the viewing device polariser is only active in the bandwidth 152, where the bandwidths 150, 152 are similar or identical. Light of wavelengths outside of the bandwidth 152 is allowed to pass with no polarisation selection and therefore no loss of light. In this way, more ambient light is allowed to pass through the viewing device, and this improves ambient visibility in low light conditions. A colour correcting filter may be applied to maintain neutral density in the selective band pass polariser.

Figure 8 shows an alternative embodiment. Figure 8(a) shows the output of the fog light using a white LED light source. As with the embodiment shown in Figure 6, the polariser in the fog light has an associated bandwidth 160 over which polarised light is allowed to pass. Light of wavelengths outside of the bandwidth 160 is blocked. In the viewing device, incoming light within the bandwidth 162 is allowed to pass (Figure 6(b)) where the bandwidth 162 is similar or identical to the bandwidth 160. Wavelengths outside of the bandwidth 162 are blocked. The system will only respond to light in the bandwidth 160 of the fog light, thereby reducing noise from external sources. In this way, an improved daylight response can be obtained. In either of the embodiments shown in Figures 6 and 8, the selective bandwidths may be any desired bandwidth in the visible or IR regions of the electromagnetic spectrum.

To avoid problems associated with changing angles off the orthogonal caused by camber in the road and uneven road surfaces etc, it has not proven practical to use a linear polarising system as an anti-dazzle utility in auto vehicles. Instead systems based on the use of circularly polarised light have been proposed - for example, a left-handed projector in the headlight might be used in combination with a right-handed analyser in the windscreen.

For this reason it is not been possible to use an anti-fog system based on linear polarisers and an anti-dazzle system of the above-described type at the same time in automobiles as they each require a different type of analyser. A further disadvantage with anti-fog systems which use linear polarisers in automobiles is that dazzle produced by equivalent systems in oncoming automobiles can be undesirably intense in the event of a road camber or an uneven driving surface.

The present inventor has realised that what is required is a polarising system that exhibits qualities of both linear and circular polarisers in such a way as to utilise the desired effects of both. This problem has been solved by providing a 'hybrid' system based on one or more elliptical polarisers. It is preferred to use a 'near linear' elliptical polariser which provides enough linearity to be used in an anti-fog utility, combined with enough properties of a circular polariser to allow for a sufficient anti-dazzle effect at the angles away from the orthogonal which can be reasonably expected to be experienced in an automotive utility.

A 'near linear' elliptical polariser is now described with reference to Figure 7. The elliptical polariser is provided such that narrow, near linear elliptical polarised light is produced, such as shown in Figure 7. For example, an angled ¼ wave plate can be used in conjunction with a linear polariser. The preferential angle of the ¼ wave plate may be of the order of, but not limited to, 5-10 degrees from an angle that would leave the linear polarised light produced by the associated (co-located) linear polariser unchanged. This produces an elliptical polarisation with a preferential axis at angle ø. The angle ø can be in the range of 5°-10°, although larger values of ø, for example, up to 20°, might be contemplated. Other optical elements having retardation properties, such as 1/8 wave plates and 1/32 wave plates may be used at an appropriate effective orientation angle to an associated linear polariser. An elliptical polariser of this type may be used as part of a light projector (e.g. in an oncoming vehicle headlight, fog light or other light projector). The viewing device or analyser may comprise a linear polariser oriented to be orthogonal to the ellipse preferential axis and thus block most of the elliptical polarised light and create an anti-fog and anti-dazzle effect. The blocking linear polariser may instead be oriented slightly away from the axis which is orthogonal to the ellipse preferential axis, for example, by up to ± ø. In another embodiment, the analyser or viewing device may comprise a 'near linear' elliptical polariser having an ellipse preferential axis which is orthogonal to the ellipse preferential axis of the light projector. The fog light in the vehicle may be fitted with a linear or a 'near linear' elliptical polariser oriented such that the light projected through it and subsequently reflected back by the water droplets in fog, is blocked by the polariser of the analyser or viewing device. For an auto utility the analyser may be a high transmittance polariser of the type described in my co-pending UK patent application numbers GB1302020.1 and 1319420.4 and International patent application WO2014/122424.

By creating a narrow, 'near linear' ellipse, a polariser has been created that has qualities approaching that of a circular polariser in that the anti-dazzle effect is less reduced at angles away from the orthogonal, as well as properties approaching that of a linear polariser. As a result, a linear analyser can be used to block light which is polarised with a polarisation state defined by the narrow ellipse. The combination narrow elliptical polariser will find utilities within the auto, marine, rail and aerospace sectors.