GB2395468A

GB2395468A - Distance indicating device

Info

Publication number: GB2395468A
Application number: GB0223408A
Authority: GB
Inventors: Maxwell Riley
Original assignee: B D I ON U Ltd
Current assignee: B D I ON U Ltd
Priority date: 2002-10-09
Filing date: 2002-10-09
Publication date: 2004-05-26
Also published as: GB0223408D0

Abstract

A distance indicating device 10 indicates to a viewer (36, fig 9) a particular distance from a transparent screen (35, fig 9) through which the viewer (36) can see a target area (38, fig 9). The device 10 comprises a base 11, 12 and an indicator 14, which is less dark than a top portion 11 of the base, so that an image of the indicator 14 may be reflected in the screen (35). The device 10 is adjacent to the screen (35) and the image is superimposed on the image of the target area (38) at a position equivalent to the particular distance. The device 10 may be mounted on a dashboard to indicate a safe braking distance to a driver, the image being reflected in a windscreen . Several horizontal bar indicators (23, fig 4) on a disk 13 rotatably mounted on a lower portion 12 of the base may be provided corresponding to braking distances at different speeds. It is envisaged that the position of the indicator may be dynamically adjusted according to the speed. A partly transparent card (45, fig 10) comprising distance markers (47, fig 10) may be provided for educational purposes.

Description

1- 2395468

Distance Indicatinn Device The present invention relates to a device for indicating distance, and in particular to a device for providing a visual marker of a particular distance 5 from a viewer's location. In a currently preferred embodiment it relates to a braking distance indicating device for vehicles, but has various other uses.

There is a need for simple distance marking equipment that is cheap to produce and effective in its operation. One important particular use for such a device would be in the visual indication to drivers of braking distances in 10 moving vehicles. GB 2 223 464 shows one method of indicating to a driver the braking distance, at some speeds, but this involved a complex two mirror arrangement that was difficult to set up and required a driver to look away from the road - which is not desirable for safety considerations.

According to the present invention there is provided an indicating device for use by a viewer to indicate a particular distance from a viewer by way of a transparent screen through which the viewer can see a target area, which device comprises a base member, an indicator for marking the distance from the viewer and which is furnished on the base member, and location means for positioning the base member adjacent the transparent screen such 20 that there is an image of the indicator reflected by the transparent screen toward the viewer's eye, whereby the reflected image of the indicator is superimposed in the viewer's eye on the image in the eye of the target area, at a position equivalent to the particular distance from the screen.

The present invention makes use of the human eye's perception that 25 an image produced by reflection originates from a position that is an Àaa a c sea a ea.

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- 2 extrapolation of the path of the light from the reflective surface to the eye.

Therefore, as in a mirror, the image appears behind the reflective surface rather than where it actually originates.

As mentioned above the present invention may find much use in 5 indicating to a driver or others the braking distance of a moving vehicle at particular speeds. In such an embodiment the device may be adapted for mounting on (or inclusion in) the dashboard of a vehicle such that the indicator reflects off the windscreen and appears at a suitable point on the driver's view of the road ahead - in the form of a head up display. The location means may 10 utilise adhesive or hook and loop fasteners to fix the base to the dashboard.

The base member is preferably an unobtrusive colour and/or shape such that its reflection is minimised. Conversely the indicator is formed from a contrasting and more reflective material such that it is visible to the driver.

The indicator might for example be a polished metal bar and the remainder of 15 the base might be formed from matt black plastic.

The indicator may be an elongate bar, with the length of the bar having a significance when viewed in reflection. When used as a vehicle braking distance indicator, the indicator bar may have a length that provides a reflective image that equates to the width of a standard road lane (12 feet in 20 the UK) when viewed at the correct distance. This can provide a quick verification that the image is correctly viewed if the image appears between the lines marking that lane. In effect the image can be locked in between the lines marking the lane to verify that the indicator is shown in the correct position. As movement of the viewer's head can alter the perceived position Àe À À À. À a À À. . . . .. À À À À À À À.

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- 3 of the indicator this positioning in the lane will allow that problem to be removed or drastically reduced.

The indicator may be adjustable such that the distance marker may be altered. A plurality of indicator bars may be provided to simultaneously or 5 selectively indicate a variety of distances. The selection or adjustment of the indicator bar may be done manually or may be achieved automatically. For example when used as a braking distance indicator the braking distance will vary dependent on the speed of the vehicle. The present invention may be connected to the vehicle speedometer to automatically position the indictor 10 bar appropriately as the speed of the car changes. The indicator may be electronically generated for example by lights, instead of being a physical entity. The indicator must be able to reflect or emit sufficient light such that it will cause a reflection of the transparent screen.

A base may be provided with a rotatable plate on which are mounted a 15 variety of differently positioned indicators that are adapted to mark different distances. These indicators can be arranged at varying radial distances from the centre of the plate and rotation of the plate may place them selectively at a viewing position. The base may further comprise a cover portion that hides the parts of the plate other than that which displays the chosen indicator at the 20 viewing position. Alternatively the indicator may move with respect to the viewer and screen such that the perceived image also moves.

The base may actually comprise an integral part of whatever it is fixed to. For example in a car the device may be constructed as part of the dashboard of a new car. Such an integral construction would need to provide Àe À e.. e Àe À À À À À À À

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- 4 means by which the indicator could be calibrated for different head positions of the viewer.

The indicator may also have an associated descriptive item or legend that is also visible in reflection. For example when used as a braking distance 5 indicator the/or each indicator may have the speed at which the braking distance is effective. For example a 40mph marker line, which would be displayed nearer the car than a 70mph marker line, could be marked accordingly to ensure that the driver is aware. This would be provided such that in reflection the orientation was correct for reading.

10 In many situations the eye position of different users will vary, and this will change the place in which the image of the indicator appears. Therefore the device may need calibration by (for example) correct positioning adjacent the screen for different users. An easy way to achieve this is to set the device in the best place using a reference marker at the correct distance as datum.

15 Selection of different speed/distance indicators should not require further calibration, as the viewer's eye position will remain constant.

The present invention if used for braking distance indication might be adapted to display standardised (or vehicle specific) braking distances for a range of speeds. For example it might be adapted to show indicators for 30 to So 150 mph (or kph).

In order that the present invention may be better understood, one particular embodiment will now be described in detail with reference to the accompanying drawings in which: .. . . .. . ....

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- 5 Figure 1 is a perspective view of an embodiment of device according to the present invention intended for indicating braking distances to a driver of a vehicle; Figure 2 is plan view of the same device; 5 Figure 3 is plan view of the indicator plate of the embodiment of Figures 1 and 2; Figure 4 is a plan view of the rotator plate of the embodiment of Figures 1 and 2, which cooperates with the indicator plate of Figure 3; Figure 5A is an exploded cross-section through the device; 10 Figure 5B is the same cross-section, but in a correct construction; Figure 6 is the embodiment of device located in a display/storage box; Figure 7 shows the device being correctly positioned on the dashboard of a vehicle; Figure 8 shows a different view of the same device being positioned on 15 a dashboard; Figure 9 shows a schematic view of how such a device works; and, Figure 10 shows a flat card that may be used to demonstrate the concept of the device.

Referring to Figure 1 and 2, the distance indicating device 10 has a 20 base member comprising a shell (having an upper part 11 and a lower part 12) and a rotating disc 13 on which are indicators 14 (only one visible). The disc has a knurled edge 15 to aid rotation thereof by hand and it comprises an interconnected rotator plate and indicator plate. The upper shell part 11 conceals all but one of the indicators, but rotation of the disc 13 will alter the 25 indicator that is shown.

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- 6 Figure 3 shows the indicator plate 2O, which is connected to the underside of the rotator plate 21, which is shown in Figure 4. The raised parts 22 of the indicator plate project through the corresponding apertures 23 in the rotator plate 21 to form the indicators 14. Clearly the indicators could simply 5 be attached to or be part of the rotator plate.

The cross-sections in Figure 5A and 5B shows these parts in relation.

The upper and lover shell parts 11 and 12 are connected together centrally and provide a bearing around which the disc 13 may rotate. The under side of the lower shell part 12 has a projection 25 which is used to locate the device to on a dashboard (not shown) by means such as self adhesive two part hook and loop fasteners.

The device 10 is shown in a display case 30 in Figure 6. The clam or bivalve shaped case has an upper part, on the inner surface of which is displayed a simulation of a road. This can be used to display to a potential 15 purchaser how the device functions. Such a case might also be provided with a screen wipe tissue to aid in setting up of the device.

The device must be correctly located to ensure that the perceived image is shown at the correct relative position. Figure 7 and 8 show ways in which the device may be so located. For example a person could sit in the 20 driving seat of a car in their normal driving position and place a reference marker (or a helpful person) at the correct distance from the stationary car.

The person in the car can then move the device until the image reflected on the windscreen corresponds to that reference position and then fix the device to the dashboard.

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- 7 Figure 9 is intended to show schematically how the device functions.

The image reflected from the device 10 bounces off a windscreen 35 toward the eye 36 of a person driving the car 37. The driver's eye perceives the reflection to emanate from ahead of the car 37 in line with a position 38 on the 5 road 39 - thus superimposing it on the driver's image of the road. The reflected image is unobtrusive and will not interfere with the driving of the car, but will allow the driver to have a ready visual guide of how close he or she should be driving to the vehicle in front.

Figure 10 shows a display card 45, with a transparent region 46.

10 Displayed in this region 46 are markers 47 that simulate the appearance of the indicators of the present invention without needing to mount the device in a car. If this card 45 is held up at arms length a person may look through the transparent region 46 toward a road. The markers 47 will be overlaid on the view to indicate how the device 10 might operate. This can be used for 15 promotional and educational purposes, and might include advertising thereon.

Whilst the present invention has been discussed almost exclusively with respect to the indication of braking distance in vehicles, other uses are clearly possible. For example the distance marker could be used in ships or planes to indicate the distance of objects. Furthermore the device could, by 20 the provision of an integral screen, be used by others such as photographers or marksmen to indicate approximate distance from their point of origin. Use of a device according to the present invention is also envisaged for police speed enforcement operations. For example the provision of the device or one working on the same principle, in a police car, or even a helicopter, could 25 be used for recording dangerous driving for later prosecution. For example, À À e À À À, À '

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- 8 the device could be fitted to project an image into a camera rather than a viewer's eye.

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Claims

- 9 - Claims

1. A distance indicating device for use by a viewer to indicate a particular 5 distance from a transparent screen through which the viewer can see a target area, which device comprises a base member for positioning adjacent the transparent screen and an indicator for marking the distance from the viewer, which indicator is furnished on the base member such that there is an image of the indicator reflected by the transparent screen toward the viewer's eye, 10 whereby the reflected image of the indicator is superimposed on the image in the viewer's eye of the target area, at a position equivalent to the particular distance from the screen.

2. A distance indicating device as claimed in claim 1, wherein the base member is adapted for releasable attachment to the dash board of a vehicle in 15 an area between the windscreen and the driver such that a distance in front of the vehicle is indicated to the driver.

3. A distance indicating device as claimed in claim 2, wherein the base is provided with releasable attachment means such as adhesive or hook and loop fasteners.

20

4. A distance indicating device as claimed in claim 1, wherein the base member is part of, or is permanently incorporated in a vehicle such that a distance in front of the vehicle is indicated to the driver of that vehicle.

5. A distance indicating device as claimed in any of the preceding claims wherein a plurality of indicators are provided to mark different distances.

25

6. A distance indicating device as claimed in any of the preceding claims, wherein the or each indicator is an elongate bar.

- 10

7. A distance indicating device as claimed in any of the preceding claims wherein each indicator is formed form material that is visibly distinct from the remainder of the device.

8. A distance indicating device as claimed in any of the preceding claims, 5 wherein the device indicates a distance in front of a vehicle travailing along a traffic lane or road, and the length of the or each indicator is configured such that it reflects an image that corresponds to the width of the traffic lane or road at the appropriate distance.

9. A distance indicating device as claimed in any of the preceding claims, 10 wherein the or each indicator is linear.

10. A distance indicating device as claimed in any of the preceding claims wherein a rotatable plate is mounted on the base and the or each indicator is mounted on that plate.

11. A distance indicating device as claimed in claim 10, wherein the base 1s includes a cover that extends over the plate and obscures all but the indicator that is currently required, and rotation of the plate will change the desired indicator.

12. A distance indicating device as claimed in claims 10 or 11, wherein each indicator is mounted on a respective radius of the plate and perpendicularly To thereto, and the radial distance of each indicator from the centre of the plate is inversely related to the distance indicated.

13. A distance indicating device as claimed in any of the preceding claims, wherein the or each indicator displays a reference legend that is correctly orientated when reflected into the viewer's eye.

- 11

14. A distance indicator as claimed in any of the preceding claims wherein a single indicator is moveably relative to the base to alter the distance indicated to the viewer.

15. A distance indicator as claimed in claim 14 and for use in a vehicle, in 5 which device the movement of the indicator is coupled to speed reading apparatus in the vehicle such that the indicator will automatically alter to dynamically indicate the correct braking distance for the vehicle at a given speed.

16. A distance indicator as claimed in claim 1 and substantially as herein 10 described with reference to and as illustrated in the accompanying drawings.