GB2497757A

GB2497757A - Variable sign with electrochromic layer

Info

Publication number: GB2497757A
Application number: GB1121846.8A
Authority: GB
Inventors: Christopher James Edward Nagle
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-12-19
Filing date: 2011-12-19
Publication date: 2013-06-26
Also published as: GB201121846D0

Abstract

A variable sign comprises an electro-optical layer, in particular an electro-chromic layer, that changes appearance in response to an electrical stimulus, and a stimulator adapted to apply an electrical stimulus to the layer. An external signal may be applied to change the sign, such signal being a clock, a radio control signal, an environmental sensor, a temperature sensor, a light sensor or a traffic sensor. A multilayered sign may be formed having multiple electro-optic layers which can be selectively changed to form a particular sign. The electro-optical layer preferably changes colour or from opaque to transparent, so that the visual detail of the sign is concealed or revealed. Such signs may be used in traffic management applications and for speed limit signs, for example.

Description

SIGN

TECHNICAL FIELD

The present invention relates to signs. In particular, the present invention relates to signs in which the appearance of the sign can be altered. Signs in accordance with some embodiments may be used in traffic management applications and for speed limit signs, for example.

BACKGROUND

Signs are used in many situations, for example to manage foot or vehicle traffic or to provide information. In some situations, such as for example a sign indicating a temporary reduction in the speed limit of a motorway, it can be useful to alter the appearance of a sign.

Previously a remotely operated blind on a frame has been disclosed in GB2370148B, in which a blind can be operated to cover or uncover the frame aperture. The frame is secured to a sign and enables the sign to be covered and uncovered under remote control.

A road sign provided with flaps movable between a first position and a second position under remote control in order to change the appearance of the sign has been disclosed in GB 23201 24B.

The present invention seeks to provide a novel sign.

SUMMARY

In accordance with one aspect of the invention, there is provided a sign having a sign face comprising at least one layer of material that changes appearance in response to an electrical stimulus; and a stimulator adapted or arranged to apply selectively an electrical stimulus to the layer.

In some embodiments the stimulator is provided with a stimulus generator that is adapted to generate the electrical stimulus and to apply the electrical stimulus to the material. The electrical stimulus may be an electrical voltage or an electrical current.

I

A-

In some embodiments the stimulator is provided with a display control operable to receive one or more external input and to cause an electrical stimulus to be generated in response to the one or more external input. In different embodiments the external input may be one or more of: a clock signal; a radio control signal; at least one environment sensor signal. In different embodiments the environment sensor signal may be one or more of: a temperature sensor signal; a light sensor signal; a traffic sensor signal.

In some embodiments at least two electrical stimuli may be applied selectively to a layer, the application of each electrical stimulus resulting in a different appearance of the layer.

In some embodiments the sign face comprises at least a first layer and a second layer, the first and second layer being arranged to be selectively supplied by a respective stimulus, in which the appearance of the first layer when in a stimulated state is different from the appearance of the second layer when in a stimulated state.

In some embodiments an electrical stimulus causes a change in the colour of the corresponding layer in a stimulated state.

In some embodiments an electrical stimulus causes a change in the transparency of the corresponding layer in a stimulated state.

In some embodiments only a portion of the area of the sign face is covered by the at least one layer.

In some embodiments the sign face comprises a sign plate and at least one layer applied thereto such that visual detail on the sign plate can be altered, concealed or revealed in response to an electrical stimulus applied to the at least one layer.

In some embodiments the layer is an electrochromic film.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic cross-sectional diagram showing a sign in accordance with one embodiment of the invention; Figure 2 is a schematic cross-sectional diagram showing a sign in accordance with an alternative embodiment; Figure 3 is a schematic cross-sectional diagram showing a sign in accordance with a further embodiment; Figure 4 is a schematic cross-sectional diagram showing a sign in accordance with a yet further embodiment; Figure 5 is a schematic diagram of one embodiment of a stimulator; Figure 6 is a schematic diagram of an alternative embodiment of a stimulator; Figure 7 is a schematic diagram of a further embodiment of a stimulator; Figures 8a-8d show the appearance of an exemplary sign in different stimulation states.

DETAILED DESCRIPTION

Embodiments of the present invention will now be described with reference to the accompanying drawings.

Figure 1 is a schematic cross-sectional diagram showing a sign 10 in accordance with a first embodiment of the invention. The sign 10 has a sign face denoted generally by bracket 12 that represents the visual appearance of the sign 10 when viewed from direction A. The sign face 12 comprises a layer 14 formed of a material that changes appearance in response to an electrical stimulus. A stimulator 16 is also provided to apply selectively an electrical stimulus to the layer 14.

The electrical stimulus may in some embodiments correspond to the application of a voltage across the layer 14, or may in other embodiments correspond to the application of a current to the layer 14. In the exemplary embodiment the layer 14 is made from an electrochromic material, which changes transparency when an electric current is passed through the material of layer 14. In some embodiments the material might change colour in response to the application of a different electrical stimulus.

In some embodiments the stimulator 16 may merely be the electrical connection coupling the layer 14 of the sign 10 to the source of electrical stimulus external to the sign. This arrangement may be used in situations where signs are indoors for example in a shopping mall or are otherwise easy to control with a wired installation.

Figure 2 is a schematic cross-sectional diagram of an alternative arrangement in which a stimulator 18 is provided as part of the sign 20. The reference numerals used in this Figure are the same as the reference numerals used for the same or similar features in Figure 1. The sign 20 is shown horizontally in Figure 2 for ease of reference although a skilled person will appreciate that in use the sign will generally be vertical.

As will be discussed with reference to the following drawings, the stimulator 18 is able to generate electrical signals to apply to layer l4so as to alter the appearance of layer 14. This arrangement in which the stimulator 18 generates electrical stimulus is suitable for embodiments implemented in situations where the sign is more remote since the operation of the sign is more self-contained.

A sign 22 in accordance with a further embodiment is shown in Figure 3 which is a cross-sectional view of a schematic diagram of a further embodiment sign. The reference numerals used in this Figure are the same as the reference numerals used for the same or similar features in Figure 1.

The sign 22 in Figure 3 is provided with a sign plate 24 and a first layer 14 and a second layer 26 applied to the surface 28 of the sign plate 24. A stimulator 18 is provided and is coupled to the first layer 14 and the second later 26 in order to apply a respective electrical stimulus to the first layer 14 and the second layer 26 as will be explained in more detail in the following description.

In some embodiments the surface 28 of the face plate is visible for at least part of the time that the sign is in operation, and may be coated with a retro-reflective material.

The electrical stimulus supplied to each layer is typically different, so as to enable a different visual image to be presented on the face 12 of the sign 22 at different times.

The combination of the stimulus applied to the different layers results in visual detail on the sign plate being altered, concealed or revealed.

Typically, a layer will either be in a stimulated state, if the electrical stimulus is being applied, or in a rest state. However, in some embodiments it is envisaged that more than one level or type of electrical stimulus might be applied to a layer, resulting in the creation of more than one stimulated state for a layer.

As will be appreciated by a skilled person, the number of layers used in a sign is a matter of design choice by a skilled person, and embodiments of the invention may be implemented with different numbers of layers on different occasions.

A sign 30 in accordance with a further embodiment is shown in Figure 4, which is a schematic cross-sectional diagram showing a sign in accordance with a further embodiment. The reference numerals used in this Figure are the same as the reference numerals used for the same or similar features in previous Figures.

The sign 30 in Figure 4 is provided with a sign plate 24 and a first layer 14, a second layer 26 and a third layer 32 applied to the surface 28 of the sign plate 24. A stimulator 18 is provided and is coupled to the first layer 14 and the second later 26 and the third layer 32 in order to apply a respective electrical stimulus 34, 36, 38 to the first layer 14, the second layer 26 and the third layer 32 as will be explained in

more detail in the following description.

The stimulator 18 comprises a display control 40 and a stimulus generator 42. The display control 40 is arranged to determine the required appearance of the face 12 of the sign 30 (not shown in Figure 4). The display control 40 is coupled to receive external inputs 44 and to use those external inputs to determine the required appearance of the face 12 of the sign 30. The display control 40 is also coupled to the stimulus generator 42 to supply a display instruction 46. In response to the receipt of a new display instruction 46, the stimulus generator generates the required electrical stimulus 34, 36, and 38 as appropriate.

Embodiments of the stimulator 18 will now be explained with reference to Figures 5- 7. The reference numerals used in this Figure are the same as the reference numerals used for the same or similar features in previous Figures. Clearly, the different embodiments shown in Figures 5-7 are not exhaustive and may be used separately, or may be combined with each other and with other arrangements, as seems appropriate to a skilled person.

In the embodiment of the stimulator 18 shown in Figure 5, a clock 50 provides a clock timer signal as an external input for the display control 40 to determine the required appearance of the sign. This enables the appearance of the sign to be altered remotely or automatically based on the time. One example of a situation in which this might be used is to lower the speed limit or adjust other traffic control signs in the vicinity of a school around the start and end of the school day.

In the embodiment of the stimulator 18 shown in Figure 6, one or more environmental sensors 52 provide an environment sensor signal 54 as an external input for the display control 40 to determine the required appearance of the sign. In the exemplary embodiment the environmental sensors 52 comprise a temperature sensor 54; a light sensor 56; and a traffic sensor 58.This enables the appearance of the sign to be altered remotely or automatically based on the sensed environment.

One example of a situation in which this might be used is to lower the speed limit or adjust other traffic control signs in the cold or bad weather, or in response to a sensed traffic load.

In the embodiment of the stimulator 18 shown in Figure 7, a radio controller 60 provides a received radio signal as an external input for the display control 40 to determine the required appearance of the sign. This enables the appearance of the sign to be altered remotely or automatically.

In embodiments of the invention use of a layer of electrochromic material having an appearance that can be changed in response to an electrical stimulus enables in the simplest application, the sign to be obscured when not required and revealed when needed. In more complex applications, for example with the use of multiple layers of electrochromic material that can be separately electrically stimulated, detail on the sign can be altered to present variable messages.

One such embodiment in which a sign is provided with three layers is shown in Figure 8a-8d. This may be implemented using an arrangement shown in Figure 4 in an exemplary embodiment. These Figures indicate the potential variable message application and the simple obscuration application of an electrochromic film.

Figure 8a shows the appearance of the sign in a first state in which none of the layers are in a stimulated state through the application of an electrical stimulus. With no layers active, the image on the sign plate 24 of Figure 4, which may be made of coloured retro-reflective material in the exemplary embodiment, is visible as shown in Figure 8a.

In the sign shown in this embodiment, the first numeral may be provided by either of two layers of electrochromic film, for example layer 26 and layer 32 of Figure 4.

Figure 8b shows the appearance of the sign when a first layer, in which a numeral 6 is made visible, is activated by stimulating the first layer e.g. layer 26 in Figure 4, with an electrical stimulus causing the 6' to appear..

Figure 8c shows the appearance of the sign when a second layer, in which a numeral 4 is made visible, is activated by stimulating the second layer e.g. layer 32 in Figure 4, with an electrical stimulus causing the 4' to appear.

Figure 3d shows the appearance of the sign when the whole sign face is obscured as a result of stimulating a third layer e.g. layer 14 in Figure 4, with an electrical stimulus.

The layer of material that changes appearance in response to an electrical stimulus used in embodiments of the present invention may be implemented in different ways, as will be apparent to a skilled person. In embodiments of the invention the layer is provided by a film of electrochromic material affixed to the sign plate or previously applied electro-chromic material film. In some embodiments a layer of for example electrochromic film in the exemplary embodiments is sandwiched between suitably framed glass or plastic sheets. In some embodiments a sign plate is not used and the material layer, for example the electrochromic film itself forms the sign.

Electrochromism is the phenomenon displayed by some materials of reversibly changing colour or transparency, for example by application of an electric current.

Various types of materials and structures used to construct electrochromic devices are available to the skilled person and can be selected by a skilled person depending on the specific application. For example, electrochromic materials available to the skilled person include tungsten oxide (Wa3), which is the main chemical used in the production of electrochromic windows or smart glass.

Although the exemplary embodiment described with reference to Figures 8a-8d refers to the different numerals viewable in Figure 8b and 8c and to the obscuring of the sign face in Figure 8d, in other embodiments a change in colour of one or more layers in response to stimulation of that layer may be used to change the appearance of the sign presented to a viewer.

In some embodiments the stimulus is applied to the layer to change the layer at least from a non-stimulated state to the stimulated state. In other embodiments the stimulus is continually applied to maintain the layer in the stimulated state.

As will be apparent to a skilled person, in some embodiments the layer of material that changes appearance in response to the stimulus may extend over the entire surface of the sign face, as for example is shown in Figure 8d. In other embodiments, the layer of material that changes appearance in response to the stimulus might not extend over the entire surface of the sign face, as for example is shown in Figures Sb and 8c in which the layer of material is formed over only the area forming the changing numbers.

As will be apparent to a skilled person a new sign is described herein that can be used in many different applications, including but not limited to speed limit signs and traffic management signs.

Claims

<claim-text>CLAIMS1. A sign having a sign face comprising at least one layer of material that changes appearance in response to an electrical stimulus; and a stimulator adapted or arranged to apply selectively an electrical stimulus to the layer.</claim-text> <claim-text>2. The sign as claimed in any preceding claim in which the stimulator is provided with a stimulus generator that is adapted to generate the electrical stimulus and to apply the electrical stimulus to the material.</claim-text> <claim-text>3. The sign as claimed in any preceding claim in which the stimulator is provided with a display control operable to receive one or more external input and to cause an electrical stimulus to be generated in response to the one or more external input.</claim-text> <claim-text>4. The sign as claimed in claim 3 wherein an external input is a clock signal.</claim-text> <claim-text>5. The sign as claimed in claim 3 wherein an external input is a radio control signal.</claim-text> <claim-text>6. The sign as claimed in claim 3 wherein an external input is at least one environment sensor signal.</claim-text> <claim-text>7. The sign as claimed in claim 6 in which an environment sensor signal is a temperature sensor signal.</claim-text> <claim-text>8. The sign as claimed in claim 6 or 7in which an environment sensor signal is a light sensor signal.</claim-text> <claim-text>9. The sign as clafrned in one of claims 6-8 in which an environment sensor signal is a traffic sensor signal.</claim-text> <claim-text>1O.The sign as claimed in any preceding claim in which at least two electrical stimuli may be applied selectively to a layer, the application of each electrical stimulus resulting in a different appearance of the layer.</claim-text> <claim-text>11.The sign as claimed in any preceding claim, in which the sign face comprises at least a first layer and a second layer, the first and second layer being arranged to be selectively supplied by a respective electrical stimulus, in which the appearance of the first layer when in a stimulated state is different from the appearance of the second layer when in a stimulated state.</claim-text> <claim-text>12.The sign as claimed in any preceding claim in which the electrical stimulus is an electrical voltage.</claim-text> <claim-text>13.The sign as claimed in any preceding claim in which the electrical stimulus is an electrical current.</claim-text> <claim-text>14.The sign as claimed in any preceding claim in which an electrical stimulus causes a change in the colour of the corresponding layer in a stimulated state.</claim-text> <claim-text>15. The sign as claimed in any preceding claim in which an electrical stimulus causes a change in the transparency of the corresponding layer in a stimulated state.</claim-text> <claim-text>16.The sign as claimed in any preceding claim in which only a portion of the area of the sign face is covered by at least one layer.</claim-text> <claim-text>17.The sign as claimed in any preceding claim in which the sign face comprises a sign plate and at least one layer applied thereto such that visual detail on the sign plate can be altered, concealed or revealed in response to a stimulus applied to the at least one layer.</claim-text> <claim-text>18.The sign as claimed in any preceding claim where the layer is an electrochromic film.</claim-text>