EP1591984A2 - Système d'éclairage pour panneau d'affichage électromagnetique - Google Patents

Système d'éclairage pour panneau d'affichage électromagnetique Download PDF

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Publication number
EP1591984A2
EP1591984A2 EP05007968A EP05007968A EP1591984A2 EP 1591984 A2 EP1591984 A2 EP 1591984A2 EP 05007968 A EP05007968 A EP 05007968A EP 05007968 A EP05007968 A EP 05007968A EP 1591984 A2 EP1591984 A2 EP 1591984A2
Authority
EP
European Patent Office
Prior art keywords
light
display
illumination
display pixel
electromagnetic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05007968A
Other languages
German (de)
English (en)
Other versions
EP1591984A3 (fr
Inventor
Janez Pirs
Silvija Pirs
Milan Bavec
Franc Justin
Silvano Medizza
Janez Ropret
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Iskra Mehanizmi Industrija mehanizmov aparatov in sistemov dd
Original Assignee
Iskra Mehanizmi Industrija mehanizmov aparatov in sistemov dd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Iskra Mehanizmi Industrija mehanizmov aparatov in sistemov dd filed Critical Iskra Mehanizmi Industrija mehanizmov aparatov in sistemov dd
Publication of EP1591984A2 publication Critical patent/EP1591984A2/fr
Publication of EP1591984A3 publication Critical patent/EP1591984A3/fr
Withdrawn legal-status Critical Current

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/37—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being movable elements
    • G09F9/375—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being movable elements the position of the elements being controlled by the application of a magnetic field
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F13/00—Illuminated signs; Luminous advertising
    • G09F13/20—Illuminated signs; Luminous advertising with luminescent surfaces or parts

Definitions

  • the objective of the present invention is the concept of illumination of electromagnetic display panels, which minimizes the light reflection from the dark background, as well as the reflections from the outer transparent protective cover and emphasizes only the light emerging from the bright luminescent surface layer on the activated display pixels.
  • the proposed illumination of electromagnetic display panels is based on the use of the luminescent dyes in absorbing light in the near-UV light range and upon absorbing the UV light reemitting the light in the visible spectral range.
  • the advantage of the new concept is that the reflected light, used for the display panel illumination, is hardly visible to the human eye and so the direct reflections from the dark, nonactivated background as well as from the outer transparent display panel protective cover is extremely low. This in turn results in extremely high display panel contrast in poor lighting conditions. As the light emitted from the display pixels is emitted in random directions, the angular visibility of such a display is excellent.
  • the technical field of the invention is the illumination of the large, bistable electromagnetic display panels, used for traffic signs, buses' and trains' destination displays, large information display panels in airports, train and bus stations and sporting events in poor lighting conditions.
  • the patent application is classified in the groups G09F 3/4 and G09F 9/37. As the visibility of these display panels is of prime importance, excellent angular visibility, visual perception and high contrast are necessary.
  • the technical problem solved by the present invention is to provide a novel, low production cost concept of illumination of the electromagnetic displays, which should provide excellent angular visibility in poor or no ambient light conditions, reduce the haze and glare caused by light scattering from the protective cover as well as light reflections from the background and display casing, which adversely affect the display contrast.
  • the electromagnetic display panels have been known for over two decades and are playing an important role in niche applications, where relatively large size, medium information content display panels, with high contrast and excellent visibility even at oblique angles in rather high ambient lighting conditions are required.
  • the bistable electromagnetic display panels (US 3,871,945, US 4,577,427, US 4,860,470, EP 0 084 959, EP 0 731 435 A1,7), used for traffic signs, buses' and trains' destination displays, large information display panels in airports, bus and railway stations and sporting events seem to comply very well with the above requirements.
  • Using bright reflective paints on the selected picture elements ("ON" state) and mate black on the nonselected areas (“OFF” state) these displays feature good contrast and excellent angular visibility in high ambient light conditions.
  • the patent solves the above-specified technical problems using external UV rather than standard visible light illumination of the electromagnetic display panels.
  • the use of color dyes absorbing light in the near-UV light range and reemitting it in the visible spectral range is necessary on the selected picture elements either in the form of UV luminescent paint or plastic material used for display pixels having the said dyes directly imbedded/dissolved in them.
  • the UV light illuminated paints with luminescent dyes are quite commonly used in various light shows (entertainment, advertisement,). No use of this display illumination concept has however been reported, where the above concept is used to reduce the haze and glare of the electromagnetic display panels resulting in increased contrast of these devices.
  • the electromagnetic displays are typically made as large matrix arrays of preferably square display pixels with movable flaps and built-in solenoids.
  • the "ON” and “OFF” state of the flaps is indicated by visually highly contrasting colors.
  • By rotating the flap around the axis by means of the magnetic field one can display arbitrary patterns.
  • the magnetic driving of the pixels provides for the inherent memory, which is essential for keeping the power consumption within the required limits.
  • the goal of the invention is achieved by using invisible UV light illumination of the display panel, which is possible, if one uses UV fluorescent dyes in the paints or plastic material for the reflective surface of the selected pixel element instead of the regular visible light reflective ones.
  • the said dyes absorb the invisible near-UV light and upon absorbing it reemit the light in the visible range - see Fig. 1.
  • Such a display panel illumination concept results in excellent contrast, as there is no visible light scattering from the background or protective top covers resulting in haze and glare.
  • the appearance / perception of the displayed characters remains unchanged in the high as well as in the low or "dark" ambient light conditions.
  • the major advantage resulting from the use of the said near-UV light illumination is not so much the bright color under UV light illumination (- any bright, properly illuminated reflective paint can do the same) but rather the lack of illumination light scattering from the background surface and display protective covers, which normally significantly degrade the standard electromagnetic display panel contrast.
  • the effect is evident even in regular illumination conditions (additional UV light increases the brightness) and is especially present in the dark ambient situations, where the electromagnetic displays according to the invention exhibit extremely high contrast without any haze due to the scattered illumination light.
  • the use of color dyes absorbing light in the near-UV light range and reemitting it in the visible spectral range is necessary in the top layer of the selected ("ON") display pixel surface either in the form of UV luminescent paint or by imbedding/dissolving the said UV luminescent dyes in plastic material used for display pixels.
  • the selected ("ON") display pixel surfaces have to reflect the visible light as well. There are several possibilities to achieve this goal, which however vary to some extent with the display pixel operation principle (see Fig. 2a, 2b and the corresponding " Detailed description " to follow).
  • the electromagnetic display panel using the display pixels made according to the above described concept behaves just like any present state-of-the-art reflective electromagnetic display panels, however if additionally illuminated with near-UV light, its brightness can be improved. It is the dark ambient condition, where the possibility of using the invisible near-UV light illumination brings the most profit, since the electromagnetic displays according to the invention exhibit extremely high contrast without any haze and glare due to the scattered visible illumination light as opposed to the present state-of-the-art solutions using illumination with standard fluorescent lights.
  • the realization of the active illumination of the electromagnetic display according to the invention is very similar to the standard concept of illumination with regular fluorescent lights. If the latter are replaced for example by the "black ray" fluorescent lights used in entertainment, advertisement etc. (See Fig. 4) or any other near-UV light source (UV LED,....), an important increase of contrast as well as important reduction of haze and glare is achieved as a result of the lack of illumination light scattering from the background surface and display protective covers, which normally significantly degrade the standard electromagnetic display panel contrast..
  • the proposed technical solution of illumination of the electromagnetic display panels by means of the invisible near-UV rather than visible light solves the problem of extending the operation of electromagnetic display panels in low and/or dark ambient light conditions in a simple, cheap and yet very efficient way.
  • the said solution strongly reduces the haze and glare of the display panel and therefore increases its contrast.
  • the proposed illumination concept can be applied generally irrespectively of the operational concept of the electromagnetic display pixels.
  • the details of the implementation however vary to some extent with the display pixel operation principle.
  • the use of color dyes absorbing light in the near-UV light range and reemitting it in the visible spectral range is necessary in the top layer of the selected ("ON") display pixel surface either in the form of UV luminescent paint or by imbedding/dissolving the said UV luminescent dyes in plastic material used for display pixel surface layer manufacturing.
  • the selected ("ON") display pixel surfaces have to reflect the visible light as well.
  • the realization of the active illumination of the electromagnetic display panel 13 (Fig 4, 5) according to the invention is very similar to the standard concept of illumination with regular fluorescent lights. If the latter are replaced for example by the "black ray” fluorescent lights 11 used in entertainment, advertisement etc. (See Fig. 4) or any other near-UV light source (UV LED,....), an important increase of contrast is achieved. In order to focus as much light on the display panel 13 an additional light reflector 10 is typically used. Irrespective of the optimization of the form of such a reflector the near-UV illumination of the UV luminescent paint covering the "ON" sections of the display pixels 13 P (Fig. 4), strongly depends on the distance between the "black ray" fluorescent light 11 and a particular section of the display panel 13 .
  • the intensity of the visible light emitted by the fluorescent dyes varies accordingly since it is proportional to the near-UV illumination.
  • the uniformity of the UV light illumination is obtained by the addition of the adequately variable gray filter 12 (see Fig 4).
  • the electromagnetic display panel is made as NxM matrix array (N-number of rows; M-number of columns) of display pixel elements, where the number of columns is typically significantly larger than the number of rows (few lines of ⁇ -numeric characters).
  • NxM matrix array N-number of rows; M-number of columns
  • the embodiments of the proposed invention mainly depend on the choice of the method of inducing the UV luminescent properties to the display pixel surface 13 P , when the display pixel is in the "ON" state, as well as on the operational principle of the electromagnetic display pixels, used in a particular application. Typical working embodiments are described in the four Examples and illustrated in the Fig. 3a, b, c and d as follows:
  • the basic operational principle of the display pixels used in this embodiment of the said "bus or train destination" electromagnetic display panel is based on the movable pixel flap 2 rotating around the pivoting axis 5 through the center of the flap 2 , which actually represents the display pixel element - the operational concept #1, as described above (see page 7 and Fig. 2a).
  • the flap 2 In order to display either "ON” or "OFF” position of the display pixel, the flap 2 has to rotate for ⁇ 180° around its pivoting axis so both sides of the flap must exhibit highly contrasting colors.
  • the flap is in this embodiment manufactured using black mate material 6 P (typically black pigmented ABS) preferably the same as used in the main body 6 of the display pixel element. So the "OFF" side 2 b of the flap exhibits black mate appearance without any further processing.
  • the "ON" side 2 a of the flap 2 is painted first with the layer (typically 10 ⁇ m thick) of paint 7 VIS containing visible light reflecting dye and finally covered with the layer of paint 7 UV containing high concentration of UV luminescent dye (for example: HOS Y3G). The latter absorbs light in the near-UV spectral range and upon absorbing reemits the light in the visible spectral range (see Fig. 1) that preferably matches the reflection spectrum of the first layer paint 7 VIS - see Fig. 3a.
  • the realization of the active illumination of the electromagnetic display panel 13 is achieved by using the "black ray" fluorescent lights 11 positioned along one or both long sides of the electromagnetic display panel 13 (See Fig. 4).
  • a light reflector 10 shaped to illuminate the display panel surface as evenly as possible, is added.
  • the near-UV illumination of the UV luminescent paint covering the display pixels 13p strongly depends on the distance between the "black ray" fluorescent light 11 and a particular section of the display panel 13 . As a result of this the intensity of the visible light emitted by the fluorescent dyes varies accordingly.
  • Uniformity of the electromagnetic display panel 13 illumination can be in principle improved by displacing the light sources away from the display panel surface, however the increase of the distance between the "black ray" fluorescent light source 11 and the display panel 13 is usually very limited by the overall constraints of the display panel 13 dimensions and mounting options. Therefore the uniformity of the UV light illumination cannot be obtained by optimizing the form of the light reflector 10 alone. In order to optimize the results optionally an adequately variable gray filter 12 is added (see Fig 4).
  • the said display panel can be manufactured so that the rotatable display pixel flaps are manufactured from a plastic material 7 having UV luminescent dyes according to the invention imbedded/dissolved in it rather than using the same material 6p, as used for the manufacturing of the body 6 of the display pixel.
  • the plastic material 7 In order that the plastic "body" of the flap 2 , made of the said material 7 , reflects bright visible light, when illuminated either by visible or near-UV light, the plastic material 7 has to be more or less transparent in the visible light spectrum and the surface of this flap opposite to the incoming light being painted with a layer 7 VIS fully reflecting the light in the visible spectrum, while the UV luminescent dyes imbedded/dissolved in the material 7 have to emit the absorbed light in preferably the same visible spectral range as the layer 7 VIS .
  • the basic operational principle of the display pixels used in this embodiment of the said "bus or train destination" electromagnetic display panel is based on display pixels, which are divided into two parts - the static display pixel surface 1a , 1b and the movable flap 2 covering only one half of the display pixel - the operational concept #2, as described above (see page 7 and Fig. 2b).
  • the asymmetric tilting flap 2 In order to display either "ON” or "OFF” state of the display pixel, the asymmetric tilting flap 2 has to rotate for ⁇ 180° around its pivoting axis. So both sides of the flap 2 a and 2 b as well as the sections of the static display pixel surface 1 a and 1 b covered by the flap 2 must exhibit highly contrasting colors in either one of its bistable positions.
  • the flap is manufactured using black mate material 6 P preferably the same as used in the main body 6 of the display pixel element. So the "OFF" side of the flap 2 b and the “OFF" section of the static display pixel surface 1 b exhibit black mate appearance without any further processing.
  • the "ON" side of the flap 2 a and the “ON” side the static display pixel surface 1 a are painted first with the layer (typically 10 ⁇ m thick) of paint 7 VIS containing visible light reflecting dye and covered with the layer of paint 7 UV containing high concentration of UV luminescent dye, which absorbs light in the near-UV spectral range and upon absorbing reemits the light in the visible spectral range (see Fig. 1).
  • the spectrum of the light emitted by the UV-luminescent dyes preferably matches the reflection spectrum of the first layer paint 7 VIS - see Fig. 3c. Tilting the flap 2 from one to another bistable position results in switching between the "ON" (bright) and "OFF” (dark) state of the display pixel.
  • the said display panel can be manufactured so that the rotatable display pixel flaps 2 as well as the static display pixel surface plate 1 (see Fig. 2b and Fig 3d) are manufactured from a plastic material 7 having UV luminescent dyes according to the invention imbedded/dissolved in it rather than using the same material 6 P , as used for the manufacturing of the body 6 of the display pixel.
  • the plastic material 7 has to be more or less transparent in the visible light spectrum and the surface of the flap 2 b has to be covered by the layer of paint 7 VIS , which fully reflects the light in the visible spectrum.
  • the display pixel surface is composed of the flap surface 2a and the section 1 a of the static display pixel surface plate 1, the latter also has to be covered on the side opposite to the incoming light by the layer of paint 7 VIS , which fully reflects the light in the visible spectrum.
  • the UV luminescent dyes imbedded/dissolved in the material 7 emit the absorbed near-UV light in preferably the same visible spectral range as the layer 7 VIS , the said display pixel exhibits intense bright state ("ON" state) under UV or visible light.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Illuminated Signs And Luminous Advertising (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)
EP05007968A 2004-04-28 2005-04-12 Système d'éclairage pour panneau d'affichage électromagnetique Withdrawn EP1591984A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SI200400128 2004-04-28
SI200400128A SI21767A (sl) 2004-04-28 2004-04-28 Osvetljevanje elektromagnetnega prikazovalnika

Publications (2)

Publication Number Publication Date
EP1591984A2 true EP1591984A2 (fr) 2005-11-02
EP1591984A3 EP1591984A3 (fr) 2006-08-16

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EP05007968A Withdrawn EP1591984A3 (fr) 2004-04-28 2005-04-12 Système d'éclairage pour panneau d'affichage électromagnetique

Country Status (4)

Country Link
EP (1) EP1591984A3 (fr)
CN (1) CN1691094A (fr)
RU (1) RU2289168C2 (fr)
SI (1) SI21767A (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8998434B2 (en) 2010-09-30 2015-04-07 Hewlett-Packard Development Company, L.P. Reflective color pixel
US9014417B1 (en) 2012-10-22 2015-04-21 Google Inc. Method and apparatus for themes using photo-active surface paint
US9164596B1 (en) 2012-10-22 2015-10-20 Google Inc. Method and apparatus for gesture interaction with a photo-active painted surface
US9195320B1 (en) 2012-10-22 2015-11-24 Google Inc. Method and apparatus for dynamic signage using a painted surface display system
US9646562B1 (en) 2012-04-20 2017-05-09 X Development Llc System and method of generating images on photoactive surfaces

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4914427A (en) * 1988-11-03 1990-04-03 The Staver Company Inc. Matrix display system and method
GB2297185A (en) * 1995-01-17 1996-07-24 Mark Iv Ind Ltd Display device with electromagnetically operated movable element and hall effect device operated light switching

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4914427A (en) * 1988-11-03 1990-04-03 The Staver Company Inc. Matrix display system and method
GB2297185A (en) * 1995-01-17 1996-07-24 Mark Iv Ind Ltd Display device with electromagnetically operated movable element and hall effect device operated light switching

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8998434B2 (en) 2010-09-30 2015-04-07 Hewlett-Packard Development Company, L.P. Reflective color pixel
US9646562B1 (en) 2012-04-20 2017-05-09 X Development Llc System and method of generating images on photoactive surfaces
US9014417B1 (en) 2012-10-22 2015-04-21 Google Inc. Method and apparatus for themes using photo-active surface paint
US9164596B1 (en) 2012-10-22 2015-10-20 Google Inc. Method and apparatus for gesture interaction with a photo-active painted surface
US9195320B1 (en) 2012-10-22 2015-11-24 Google Inc. Method and apparatus for dynamic signage using a painted surface display system
US9576551B2 (en) 2012-10-22 2017-02-21 X Development Llc Method and apparatus for gesture interaction with a photo-active painted surface
US9804683B1 (en) 2012-10-22 2017-10-31 X Development Llc Method and apparatus for gesture interaction with a photo-active painted surface

Also Published As

Publication number Publication date
SI21767A (sl) 2005-10-31
EP1591984A3 (fr) 2006-08-16
RU2289168C2 (ru) 2006-12-10
RU2004134002A (ru) 2006-05-10
CN1691094A (zh) 2005-11-02

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