FI113501B - Variable content traffic sign - Google Patents

Description

1 113501

Variable content traffic sign

Background of the Invention

The invention relates to the application of digital display techniques to traffic signs.

5 Digital displays have also been applied to traffic signs when seeking a sign that can be changed according to, for example, the time of year or the day. A typical case of a road sign with a digital display requires a change in the speed limit sign. Currently, modifiable road signs use displays based on LED technology (Light Emitting Diode) or Reverse Panels. A LED, or light-emitting diode, is a semiconductor component that emits visible light when an electric current is passed through it. LEDs can emit infrared, red, yellow, green and blue colors, but the light they emit is not very bright. The light-emitting diodes can be made into a dot matrix display or a bar-stretched segmental view. 15 Rotating panels provide a segment view.

U.S. Patent No. 6,317,108 B1 discloses an upgradeable traffic sign feature based on electrostatically operated electrode closures whose position can be changed from a light-transmissive to a light-opaque position. According to the publication, such a display can achieve high-20 resolution both day and night with low costs.

The problem with the arrangements described above, however, is that the cost of setting up and moving a traffic sign based on LED technology is * * considerably high. The LED-based road sign is relatively:. ·. clumsy, and this technology also requires a lot of maintenance, being sensitive to 25 faults. In addition, the LED display has poor contrast in bright weather. Segmenttinäy-. : At work, the character selection is limited. For example, a 7-segment display can execute numbers but not all letters. The problem with the arrangement described in US 6,317,108 B1 is that the static electricity display described is susceptible to interference and the large display is updated slowly.

BRIEF DESCRIPTION OF THE INVENTION I: The object of the invention is thus to provide a traffic sign to be changed so that the above problems can be solved. The object of the invention is achieved by a traffic sign which is characterized by what is stated in the independent claim. Preferred embodiments of the invention are claimed in the dependent claims.

2 113501

The invention is based on the fact that the display of the traffic sign to be changed is implemented in a so-called. e-paper. The electrical paper comprises encapsulated pigment particles which, depending on the color, have a positive or negative electrical charge. When applied to the electrical paper, the particles charged in the electric field settle in capsules according to the electric field. An electric field of suitable shape will produce the desired pattern on the screen. The pattern can be changed by changing the electric field, whereupon the charged particles settle in the capsules. Therefore, the design or text of the traffic sign can be changed as needed.

An advantage of the traffic sign according to the invention is that, when implementing the traffic sign 10 on an electric paper display, the installation and operating costs of the traffic sign are low. The display can be attached to existing traffic signs in the same way as a sticker. The text on the screen also stands out in bright sunlight. The power consumption of the e-paper display is low because it requires power only when updating the display and the display is updated quickly. Existing telecommunication connections can be utilized in the implementation of the Kek-15 invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail in connection with preferred embodiments with reference to the accompanying drawings, in which: Figure 1 shows a simplified structure of electrical paper;

Figure 2 shows a simplified traffic sign in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION Electric paper is a display technology based on electrically charged pigment particles and their arrangement according to an electric field. The first applications of e-paper have been advertising signs. Signs can be used to exchange variable information from a central computer. In electrical paper, color contrasts are achieved with an "electrical ink" comprising transparent, diameters of which; also micrometers capsules containing a polymer solution. For example, the solution contains black and white pigment particles having different electrical charge. With a suitably aligned electric field, pigment particles are obtained. Swim on either the surface or the bottom of the capsule, whereby the color of the surface of the capsule can be varied, for example, from dark to light and vice versa. Text or pattern on electric paper can be read without a separate backlight, and maintaining the image does not require continuous electrical power.

3 1125C1 The paper has a minimum working temperature of approximately +5 ° C. At temperatures below this level, the paper may become unusable and therefore not suitable for use in cold climates.

Figure 1 illustrates the working principle of electric paper. Electropa 5 is made of a plastic film 1-2 containing capsules 1-1 containing pigment particles 1-3,1-4. The pigment particles in the electrical paper are positively or negatively charged, for example, with the light particles 1-3 having a positive electrical charge and the dark particles 1-4 having a negative electrical charge, or vice versa. When an electric field is applied to the electrical paper by means of the base electrodes 1-5 and the transparent surface electrode 1-6, the charged particles 1-3, 1-4 are positioned on the surface or the bottom of the capsule 1-1 according to the electric field. The color that is visible from the outside depends on which pigment material settles on the surface of the capsule 1-1 and on the bottom of the capsule 1-1. An electric field that is suitably shaped can provide the desired pattern on the screen. More specifically, the working principle of electric paper is described, for example, in U.S. Patent No. 6,422,687 B1.

Figure 2 is a simplified representation of a variable traffic sign with an electric paper display 2-2 according to a first preferred embodiment of the invention. Display 2-2 is mounted on the back of the traffic sign 2-1, for example, as a sticker. The electric field applied to the display pigment-containing capsules is preferably implemented at a voltage of 5 V from the power supply. The pattern 2-3 formed from the capsules can be changed by changing the electric field of the electrical paper, whereby the charged pigment particles in the capsules are resettled by the new electric field. This allows you to change the shape or text of the traffic sign as needed. The sign is controlled by a control panel '': 25 signal that controls the electric field applied to the display. Brand.; j can also operate independently, preferably being pre-programmed by others. \: to adjust the screen pattern, for example, by date.

According to a preferred embodiment of the invention, a heating element comprising a temperature measuring sensor and a heater for keeping the temperature of the display in a suitable temperature range are connected to the traffic sign; which depends on the properties of the paper used. Typically, this refers to a temperature of at least 10 ° C in order to keep the electrical paper functional. The heater is, for example, a heat film of the glass heater type; operation is based on the warming up of a thin resistance wire network. In order to prevent the magnetic field formed by the operation of the heating element from interfering with the operation of the display paper, a transparent insulating board or the like having a low electrical conductivity is preferably installed between the display and the heating element.

According to a further preferred embodiment of the invention, the cold resistance of the electric paper used in the road sign is improved by adding to the invisible pigment capsules an antifreeze agent such as an alcohol. Examples of typical antifreeze agents are ethylene glycol and propylene glycol.

According to a further preferred embodiment of the invention, the electric paper display of the traffic sign is protected against the effects of weather and vandalism or other wear and tear. This is done by placing a transparent Plexiglas or similar on the screen. It is preferably made of a material having good impact resistance and / or low reflectivity. The plexiglass used to protect the sun from the harmful effects of ultraviolet radiation preferably has a filtering feature of ultraviolet rays. In order to prevent the Plexiglas from accentuating the sun-warming effect of the sun in warm weather and, on the other hand, the cold-weathering effect of cold weather, the Plexiglas used is preferably made of a material with low thermal conductivity.

According to a further preferred embodiment of the invention, the electrical paper used in the road sign contains a light reflecting agent to improve the visibility of the 20 electrical paper displays in the dark. The reflectivity may be based, for example, on phosphorescence by using a phosphorescent pigment in an electrical paper such as an alkali metal sulfide or zinc sulfide. A: Although the invention has been described above using, as an example, an embodiment of an electric paper comprising two pigments of different colors, it is not intended to: limit the invention to this embodiment, but the traffic sign of the invention may also be implemented colored pigment, · mentholed paper. Preferred embodiments of the invention are not intended to be limited to use on road signs alone, but may be contemplated for use in any subject where electrical paper requires improved cold resistance and / or visibility in poor lighting conditions; Sessa. An example of such an electronic paper application is outdoor advertising. * 'Set.

It will be obvious to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims.

* I ♦ »»

Claims (5)

5, 112501 A road sign with a removable display, comprising a backing portion (2-1) mounted on a removable display (2-2), characterized in that said removable display (2-2) is an electrical paper comprising at least 5 pigments (1). -3, 1-4) containing pigment capsules (1-1), wherein the pattern (2-3) displayed on the changeable display (2-2) is changeable by changing the position of the pigment (1-3,1-4) in the capsules (1-1) electric field. A traffic sign according to claim 1, characterized in that it comprises a heating element for controlling the temperature 10 of the display (2-2) to be changed. Traffic sign according to claim 1 or 2, characterized in that said pigment capsules (1-1) contain an antifreeze display (2-2) for improving cold resistance. A traffic sign according to claim 1, 2 or 3, characterized in that the display (2-2) to be changed is covered with a protective plate. A traffic sign according to any one of claims 1 to 4, characterized in that said pigment capsules (1-1) contain at least one phosphorescent and / or reflective agent to improve the visibility of the traffic sign in low light. t · »• I · I 1 I ·» 6 113EC1