WO2004053817A1

WO2004053817A1 - A highway display

Info

Publication number: WO2004053817A1
Application number: PCT/IE2002/000167
Authority: WO
Inventors: Kevin Grogan; John Gerard Walsh; Kevin Patrick Neville
Original assignee: Textmate Limited
Priority date: 2002-12-10
Filing date: 2002-12-10
Publication date: 2004-06-24
Also published as: AU2002348699A1

Abstract

+ highway display unit (1) for displaying information to motorists comprises a framework (2) carrying a plurality of display panels (3), each display panel having a base support mounting a programmable array of light emitting sources (4). A receiver for receiving program data and a processor for processing data are also provided. A plurality of partition walls arranged in a matrix of rows and columns are provided such that each individual light emitting source in the programmable array is surrounded by a pair of adjacent row partition walls (6) and a pair of adjacent column partition walls (7). Spacing between the column partition walls (7) in adjacent columns and the spacing between row partition walls (6) and adjacent rows and the height of the row and column partition walls define a viewing window within which the light emitting source may be viewed.

Description

"A Highway Display"

Introduction

This invention relates to a highway display unit for displaying information to motorists comprising a framework carrying a plurality of display panels, each display panel having a base support mounting a programmable array of light emitting sources, the light emitting sources being arranged in a matrix of rows and columns on the base support, a receiver for receiving program data and a processor for processing the received program data and configuring the programmable array according to the received program data.

In an effort to improve road safety and motorist awareness, government agencies and road authorities have begun providing programmable highway displays. These highway displays may be controlled remotely to display information relevant to motorists. This information may relate to traffic congestion on a particular route, a modified speed limit in operation or information relating to accidents, road conditions and the like.

Heretofore, these displays have been found to be relatively expensive to manufacture and to maintain. This is largely due to the complexity of the displays and in particular the complexity of the so called "second stage optics" of the display. These second stage optics generally comprises a magnification stage to amplify the light from a primary stage optics which consists of a low power consuming light source. In addition to the magnifying function of the second stage optics they also provide a deflecting function to prevent direct light from the sun or other such source from reflecting off the light source in the primary stage optics. This is very important as light reflected off the light source in the primary stage optics may result in the information on the display becoming illegible. Motorists must be able to read the information on the display at all times, day or night. As already mentioned, these second stage optics significantly increase the overall cost of highway display manufacture and maintenance.

It is an object therefore of the present invention to provide a highway display that is both simple and cost efficient to manufacture, less expensive to maintain and highly legible.

Statements of Invention.

According to the invention there is provided a highway display unit for displaying information to motorists comprising a framework carrying a plurality of display panels, each display panel having a base support mounting a programmable array of light emitting sources, the light emitting sources being arranged in a matrix of rows and columns on the base support, a receiver for receiving program data and a processor for processing the received program data and configuring the programmable array according to the received program data, characterised in that:

there is provided a plurality of partition walls mounted on the base support, the plurality of partition walls being arranged in a matrix of rows and columns such that each individual light emitting source is surrounded by a pair of adjacent row partition walls and a pair of adjacent column partition walls thereby defining an individual display segment, the spacing between column partition walls in adjacent columns and the spacing between row partition walls in adjacent rows and the height of the row partition walls and column partition walls above the light emitting source defining a viewing window within which the light emitting source may be viewed directly.

By providing such a highway display there is no longer a need for expensive second stage optjcs to carry out a deflecting function. The matrix of rows and columns of partition walls will prevent light from entering the individual display segment and reflecting off the light source allowing the information on the display to be viewed from within the viewing window at all times. Light directed at the display from a side will be unable to reflect off the light sources due to the column partition walls. This is a particularly simple and cost efficient display to manufacture and maintain.

In another embodiment of the invention there is provided a highway display unit in which the row partition walls are substantially horizontal with respect to the horizon and the column partition walls are substantially orthogonal thereto. This is seen as particularly preferred as it is simple to construct as well as providing the maximum protection to each of the light sources.

In a further embodiment of the invention there is provided a highway display unit in which the row partition walls protrude a greater distance from the base portion than the column partition walls. In this way the highway display information will be able to be viewed from a wider horizontal viewing window angle allowing motorists more time to read the information as they are travelling past the display. In addition to this a more uniform view of the sign is presented to the motorist.

In another embodiment still of the invention there is provided a highway display unit in which the height and spacing of the vertical column partition walls is such that the horizontal viewing window angle is between 15° and 27°. Preferably, the height and spacing of the vertical columns is such that the horizontal viewing angle is approximately 20 °. This is seen as sufficient to allow motorists enough time to view the displayed information as well as the information remaining legible whilst still providing adequate protection to the light source. By preventing viewing from an angle of greater than 27° the display will not distract motorists once they have passed the viewing angle and furthermore will help to obviate misinformation to motorists reading the sign from an obtuse angle.

In a further embodiment of the invention there is provided a highway display unit in which the vertical columns are 25mm in height and spaced 20mm apart.. These dimensions are preferred as the structure remains lightweight and simple to manipulate thereby facilitating maintenance work.

In one embodiment of the invention there is provided a highway display unit in which the height and spacing of the horizontal partition rows is such that the vertical viewing window angle is between 4 ° and 10 °. Preferably, the height and spacing of the horizontal partition rows is such that the vertical viewing window angle is approximately 6 °. This angle is seen as preferred as motorists will be able to view the displayed information from considerable distances whilst the light sources remain protected from direct light reflecting off them.

In one embodiment there is provided a highway display unit in which the height of the horizontal rows is 30mm and the spacing between adjacent horizontal rows is 10mm. Again, by having these dimensions the entire structure will remain lightweight and simple to manipulate thereby facilitating both construction and maintenance.

In another still embodiment of the invention there is provided a highway display unit in which the partition walls are covered in a matt coating. This will further reduce the possibility of reflection of light off the light source. The matt finish will absorb the light incidental on the partition walls thereby preventing the light travelling beyond the partition walls onto the light source.

In one embodiment of the present invention there is provided a highway display unit in which the light emitting sources are provided by light emitting diodes (LEDs). These are seen as particularly preferred as they are robust as well as being relatively cheap in terms of purchase and operation. In one embodiment there are provided amber LEDs having a minimum brightness in the range of 4 to 5.5 candellas. Preferably though they will have a minimum brightness of 4 candellas. This will ensure that they can be seen at all times when illuminated whilst only using the minimum amount of power. In another embodiment there are provided red LEDs having a minimum brightness in the range of 3 to 4.5 candellas. Preferably though they will have a minimum brightness of 3 candellas. By having a highway display with LEDs with these brightness ratings the highway display does not have to be provided with a magnification stage for the light source display to be viewed from great distances whilst also being sufficiently bright to allow the sign to be viewed in all conditions. The use of these LEDs also helps to reduce the overall cost of manufacture of the highway display.

In a further embodiment of the invention there is provided a highway display unit in which there are provided light emitting sources of two different colours. By providing two different colours more flexibility is given to the individual sending program data to the programmable array and detailed pictorial information may be displayed, This may be particularly useful for displaying speed limits or warning notices using the instantly recognisable Highway Code pictorial images. In a further embodiment of the invention. there are provided red LEDs and amber LEDs, the red LEDs having a minimum brightness of 3 candellas and the amber LEDs having a minimum brightness of 4 candellas. This will reduce the time spent by motorists reading the information and will further enhance road safety.

In one embodiment of the invention there is provided a highway display unit in which light emitting sources of one colour are placed in one row of the array and the next adjacent row of the array is populated with light emitting sources of the other colour. This is seen as particularly useful as the highway display will be simpler to both construct and to program. Additionally greater flexibility in pictorial image generation is provided.

in a further embodiment still of the invention there is provided a highway display unit in which the spacing between the light emitting sources in adjacent columns is twice the spacing between light emitting sources in adjacent rows. By using this configuration, uniform, clear pictorial images may be shown on the highway display.

In one embodiment of the invention there is provided a highway display unit in which there is provided means to detect the failure of a light emitting source, and the processor further comprises means to determine the position in the display panel where the displayed information according to the program data is to be positioned, means to ascertain whether on determining the position where the displayed information is to be placed that the necessary light emitting sources are operational and can display the desired information according to a predefined display criteria and means to interactively reject a position and determine an alternative position until a position satisfying the display criteria is determined and using the position that satisfies the display criteria for placement of the information on the display panel. This is seen as particularly preferred as the display can adapt to provide displayed information that conforms to the predetermined display criteria. This will allow the information to be viewed correctly even when several of the light emitting sources have failed. The information is simply moved to a position on the highway display where it can be viewed clearly. This will further help to reduce the maintenance costs of the highway display as replacement of light sources and general maintenance can be carried out at less frequent intervals. Again, this is seen as particularly advantageous. In another embodiment of the invention there is provided a highway display unit in which each display panel is releasably connected to the framework so that the individual display panel may added to or removed from the framework when necessary. In this way each panel may be replaced in a simple and efficient manner if it should fail or if a certain number of LEDs on the panel should fail. This will allow for a highway display unit that is simple to maintain as a single display panel can be changed without having to take the entire highway display out of commission. Furthermore, the provision of releasably connected display panels will allow for the display unit to be constructed in a modular format allowing varying numbers of display panels to be used for different units.

Detailed Description.

The invention will be more clearly understood from the following description of some embodiments thereof given by way of example only and with reference to the accompanying drawings in which:-

Fig. 1 is a perspective view of a highway display unit according to the invention;

Fig. 2 is a front view of a display panel according to the invention;

Fig. 3 is a side view of the display panel of Fig. 2;

Fig. 4 is a top plan view of the display panel of Fig. 2;

Fig. 5 is a rear view of the display panel of Fig. 2;

Fig. 6 is an enlarged part sectional view of the top plan view shown in

Fig. 4;

Fig. 7 is an enlarged part sectional view of the side view shown in Fig. 3; and Fig. 8 is a flow diagram outlining the procedure for positioning information on the display according to the present invention.

Referring now to the drawings and initially to Fig. 1 thereof there is shown a highway display unit, indicated generally by the reference numeral 1 comprising a framework 2 having a plurality of display panels 3 mounted thereon. Each of said display panels 3 has a programmable array of light emitting sources 4. A receiver (not shown) for receiving program data and a processor (not shown) for processing the program data and configuring the programmable array according to the received program data are additionally provided.

Referring now to Figs. 2 - 7 inclusive of the drawings there is shown various different detailed views of the display panel 3. The display panel 3 comprises a base portion 5 having the programmable array of light emitting sources 4 mounted thereon. The programmable array of light emitting sources is arranged into an array of rows and columns. A plurality of partition walls, more specifically a plurality of horizontal row partition walls 6 and a plurality of vertical column partition walls 7 are also mounted on the base support 5. The row partition walls 6 and the column partition walls 7 are arranged to form a matrix of rows and columns such that, each individual light source 4 is surrounded by a pair of adjacent row partition walls 6 and column partition walls 7. The height of the row and column partition walls and the spacing between adjacent pairs of row partition walls 6 and the spacing between the adjacent pairs of column partition walls 7 define a viewing window within which the light emitting source may be viewed directly.

The row partition walls 6 are spaced a distance d apart and the column partition walls 7 are spaced a distance 2.d apart. In this way, a pair of adjacent light emitting sources in one column of the programmable array are spaced apart twice the distance separating a pair of adjacent row light emitting sources. In this embodiment, the row partition walls 6 are spaced 10mm apart and the column partition walls 7 are spaced a distance 20mm apart. The row partition walls 6 have a height of 30mm above the light emitting source whereas the column partition walls 7 have a height of 25mm above the light emitting source 4. This leads to a horizontal viewing window angle α, in this case approximately 20° and a vertical viewing window angle β , in this case approximately 6°. The partition walls are covered in a matt coating to prevent reflection of any light incident thereon onto the light source. Instead of being reflected on to the light source, the light is simply diffused.

The light emitting sources 4 are provided by way of light emitting diodes (LEDs). Two different colours of LEDs 4a and 4b, are provided in the programmable array of light sources to allow for greater flexibility in information presentation. LEDs 4a of all one colour populate a row of the programmable array where LEDs 4b of the other colour populate the next adjacent row. In this way the programmable array will have rows of LEDs alternating in colour. In the embodiment shown the colours of the LEDs are amber and red. The amber LEDs have a minimum brightness rating of 4 candellas whereas the red LEDs have a minimum brightness rating of 3 candellas.

In use, program data is sent from a control centre (not shown) to the highway display unit where it is received by the receiver. The receiver passes the program data to the processor where the data is processed and the processor configures' the programmable array to display the information relating to the program data. The information displayed may then be displayed to passing motorists.

Referring now to Fig. 8 of the drawings there is shown a flow diagram outlining the process for positioning information on the highway display programmable array. In step 11 , the receiver receives program data from the control centre. This program data is then passed to the processor where in step 12 the program data is processed and the information to be displayed is ascertained by the processor. In step 13 the processor accesses a look-up table in processor memory (both not shown) to select a position on the programmable array for placement of the information. The look-up table contains a preferred position on the programmable array for the information to be displayed including a list of all light emitting sources that will have to be illuminated for that particular information and position. The highway display unit has means to detect the failure of a light emitting source (not shown), and a table of failed light emitting sources is further stored in processor memory. In step 14, the processor checks the availability of the^{" "}chosen ^"position ^" by comparing the ^"look-up table containing the list of all light emitting sources necessary to display the information in the selected position with the table of failed light emitting sources. The processor thereby determines whether a predetermined set of display criteria have been met. If the display criteria have not been met, the processor returns to step 13 where the next most suitable position for the information to be displayed is selected. If, however, the position is in fact available, or in other words that the display criteria have been met, the processor proceeds to step 15 where it configures the programmable array. The process then proceeds to step 16 where the processor awaits further program data.

What must be understood is that the display unit has means to determine the position of the information to be displayed on the programmable array. It checks whether the selected position has a sufficient number of light emitting sources operational to meet the display criteria and if there are insufficient light emitting sources working then the display unit selects another position. There is described a table of positions in order of preference from which the position is chosen, however, the highway display unit could have a constant starting position for all types of information and would simply shift the starting position of the information on the programmable array and therefore the entire position of the displayed information by a predetermined number of rows and/or columns of the programmable array. What is important is that there is a highway display in which if the information cannot be correctly displayed in the preferred position at least one attempt is made to display the information in another position where it can be displayed correctly. By having such a display unit, there is introduced a certain degree of redundancy to the display unit so that it will continue to display the information even if certain components fail.

Indeed, failure of the light emitting source need not mean that the light emitting source is no longer operational. It could in fact be that the light emitting source has been on or alternatively constantly on for a predetermined length of time.

The vertical viewing window angle of the highway display is preferably 6°, however, it has been found to be acceptable to have a vertical viewing window angle of between 4° and 10°. Similarly, although the preferred horizontal viewing window angle is 20°, angles between 15 ° and 27 ° have been found to be adequate in certain cases. The vertical and horizontal viewing angles may vary depending on whether or not the highway display itself has been offset to the vertical or horizontal planes. The LEDs should have a minimum brightness of 4 candellas for amber LEDs and 3 candellas for red LEDs. The amber LEDs could have a minimum brightness in the range of 4 to 5.5 candellas and the red LEDs could have a minimum brightness in the range of 3 to 4.5 candellas. In this specification the term "light sources" and "light emitting sources" have been used interchangeably and are deemed equivalent in every way.

It is envisaged that any number of display panels could be mounted on the framework. In this way they can be providedirrar odular fastτioH^"a-τd1he^~appropriate^~πQτn ϊe^"rόf^" display panels may be provided for each display. The modular units can then be replaced individually without requiring the entire highway display to be replaced.^' It is further envisaged that each individual unit may be provided with a handle or suitable indentation in its body for ease of manipulation of the unit.

In this specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms "include, includes, included, and including" or any variation thereof are all deemed to be totally interchangeable and should be afforded the widest possible interpretation.

This invention is in no way limited to the embodiments hereinbefore described and may varied in- both construction and detail within the scope of the claims.

Claims

Claims.

1. A highway display unit (1) for displaying information to motorists comprising a framework (2) carrying a plurality of display panels (3), each display panel having a base support mounting a programmable array of light emitting sources (4), the light emitting sources being arranged in a matrix of rows and columns on the base support, a receiver for receiving program data and a processor for processing the received program data and configuring the programmable array according to the received program data, characterised in that:

there is provided a plurality of partition walls mounted on the base support, the plurality of partition walls being arranged in a matrix of rows and columns such that each individual light emitting source is surrounded by a pair of adjacent row partition walls (6) and a pair of adjacent column partition walls (7) thereby defining an individual display segment, the spacing between column partition walls in adjacent columns and the spacing between row partition walls in adjacent rows and the height of the row partition walls and column partition walls above the light emitting source defining a viewing window within which the light emitting source may be viewed directly.

2. A highway display unit (1) as claimed in claim 1 in which the row partition walls (6) are substantially horizontal with respect to the horizon and the column partition walls (7) are substantially orthogonal thereto.

3. A highway display unit (1) as claimed in claim 1 or 2 in which the row partition walls (6) protrude a greater distance from the base portion than the column partition walls (7).

4. A highway display unit (1) as claimed in any preceding claim in which the height and spacing of the vertical column partition walls (7) is such that the horizontal viewing window angle is between 15° and 27°.

5. A highway display unit (1) as claimed in claim 4 in which the height and spacing of the vertical columns (7) is such that the horizontal viewing window angle is approximately 20°.

6. A highway display unit (1) as claimed in claim 5 in which the vertical columns (7) are 25mm in height and spaced 20mm apart.

7. A highway display unit (1) as claimed in any preceding claim in which the height and spacing of the horizontal partition rows (6) is such that the vertical viewing window angle is between 4° and 10°.

8. A-- highway display unit (1) as claimed in claim 7 in which the height and spacing of the horizontal rows (6) is such that the vertical viewing window angle is approximately 6 °.

9. A highway display unit (1) as claimed in claim 8 in which the height of the horizontal rows (6) is 30mm and the spacing between adjacent horizontal rows is 10mm.

10. A highway display unit (1) as claimed in any preceding claim in which the partition walls (6,7) are covered in a matt coating.

11. A highway display unit (1) as claimed in any preceding claim in which the light emitting sources are provided by light emitting diodes (LEDs).

12. A^'highway display unit (1) as claimed in claim 11 in which there are provided amber LEDs, the amber LEDs having a minimum brightness in the range of 4 to 5.5 candellas.

13. A highway display unit (1) as claimed in claim 12 in which the amber LEDs have a minimum brightness of 4 candellas.

14. A highway display unit (1) as claimed in claim 11 in which there are provided red LEDs, the red LEDs having a minimum brightness in the range of 3 to 4.5 candellas.

15. A^'highway display unit (1 ) as claimed in claim 14 in which the red LEDs have a minimum brightness of 3 candellas.

16. A highway display unit (1) as claimed in any preceding claim in which there are provided light emitting sources of two different colours.

17. A highway display unit (1) as claimed in claim 16 in which there are provided red LEDs and amber LEDs, the red LEDs having a minimum brightness of 3 candellas and the amber LEDs having a minimum brightness of 4 candellas.

18. A highway display unit (1) as claimed in claim 16 or 17 in which light emitting sources of one colour are placed in one row of the array and the next adjacent row of the array is populated with light emitting sources of the other colour.

19. A highway display unit (1) as claimed in claim 18 in which the spacing between the light emitting sources in adjacent columns is twice the spacing between light emitting sources in adjacent rows.

20. A highway display unit (1) as claimed in any preceding claim in which there is provided means to detect the failure of a light emitting source (4), and the processor further comprises means to determine the position in the display panel (3) where the displayed information according to the program data, is to be positioned, means to ascertain whether on determining the position where the displayed information is to be placed that the necessary light emitting sources are operational and can display the desired information according to a predefined display criteria and means to itteratively reject a position and determine an alternative position until a position satisfying the display criteria is.- determined and using the position that satisfies the display criteria for placement of the information on the display panel.

21. A highway display unit (1) as claimed in any preceding claim in which each display panel (3) is releasably connected to the framework so that individual display panels (3) may be added to or removed from the framework when necessary.

LK/prelim14.PS0221