FR2789768A1 - Lighting assembly of LED back lighting apparatus for use in fuel dispenser, has light emitting diodes arranged in matrix configuration so that light emanations from specific diodes overlap with other diodes in array - Google Patents

Abstract

Multiple light emitting diodes are disposed on circuit board assembly (18) in a matrix configuration, to illuminate back lighting surface of liquid display. The light emitting diodes are disposed in an offset manner, such that light emanations from the specific diodes overlap with other light emitting diodes provided in the array.

Description

Technological background of the invention.

  The present invention relates to a lighting device for a rear-lit display, this lighting device comprising a circuit board; a set of light sources distributed on the circuit board

  cooked in a network configuration, this set of sources

  these lights being intended to illuminate the light surface

rear rage of the display.

  The invention relates generally to an apparatus

  rear lighting of an LCD type display and more

  particularly a lighting device using a

  bucket of photo-emissive diodes, offset, to illuminate the liquid crystal display which is preferably part

  of the display integrated into a fuel distribution system

S15 rant.

Description of the prior art.

  Display devices of the type used

  Health LCD displays require some background or background lighting for

  the observer can clearly read the alphanumeric characters-

  risks activated on the display when the light is weak or without ambient light. Efforts to achieve such rear lighting have resulted in a lighting fixture

  which generates an appropriate light beam and directs it

  accurate to the rear LCD surface. One of the zones

  concerned is to prevent the light surfaces from

  centered, known under the name of "hot spots",

  do not appear on the bottom of the liquid crystal display

  of. Their appearance, which is easily distinguished with the naked eye, deteriorates the quality and efficiency of lighting by

  the rear, fitted to the lighting fixture.

  Previous achievements of lighting devices

  rear rage used so-called cathode devices

  cold, with hot channel, to illuminate the LCD display. From-

  very classic fixtures used photo diodes

  emissive LEDs to generate light energy which is then transmitted to the LCD display. These arrangements typically address the hot spot problem using the LED, LCD configurations, avoiding direct projection of LED light onto the rear surface of the LCD display. Through

  example, a reflector structure can be interposed

  be the LED assembly and the display to send the LED emissions to the rear LCD surface. For this, the structure of re-

  flector is typically treated with a coating

  ment of material to reduce the general concentration

  light characteristic of hot spots.

  Although the indirect projection of the image of the LED diodes on the LCD display can reduce hot spots to a certain extent, by experience this improvement results in an increase in cost and in the number of components due to the addition of 'a reflector structure. In addition, the integration of such a reflection characteristic imposes very strict tolerances on the orientation and the spatial relationship of the devices because the imprecise alignment between the different devices can prevent correct lighting of

  the fixed rear light area for the LCD display.

  Another difficulty in such a rear lighting device is the non-uniformity of the LED lighting scheme both from the point of view of

  intensity and degree of coverage. For example, the sche-

  Lighting masts created by conventional LED diode distributions for rear lighting are distinguished by insufficient lighting zones and even black dots without any light. This overlapping of the lighting scheme with such unlit or dimly lit areas results in conventional back lighting unacceptable for most commercial applications based on display units having a LED back light fixture

  as the main interface device for the customer.

Summary of the invention.

  The present invention relates to a lighting device for back lighting of a liquid crystal display (LCD). The lighting device comprises a set of photo-emissive diodes placed on a circuit board according to an array. The network configuration is

  preferably defined by a set of rows formed cha-

  no LEDs and each row of LEDs is pre-

  ference offset from adjacent rows of LED diodes. This offset is sufficient to allow the light

  emitted by each of the LEDs overlap the emission lu-

  at least one other LED diode. This overlap allows the collective light emissions of all the LED diodes to illuminate the rear lighting surface of the LCD display with a composite lighting scheme distinguished by the practically total absence of non-visible areas. shouted out. In addition, the LED network is preferably configured in relation to the LCD display so that the emissions from the LED diodes arrive directly on the rear lighting surface.

  of the LCD display. The lighting device is particularly

  very interesting if it is part of a display unit

  associated with a fuel distribution installation.

  According to one characteristic, the invention comprises a lighting device intended to cooperate for the rear lighting of a display. The lighting device comprises a circuit plate and a set of light sources placed on the circuit plate in a network configuration so that all of the light sources cooperate

  to illuminate the rear lighting surface of the display.

  The network configuration of all light sources

  ses is characterized by at least one distribution of sources

  light sources comprising light sources, offset with respect

  port to at least one other distribution of light sources

  formed from some of the other light sources.

  The network configuration of all the light sources is defined in a form by a set of distribution rows of light sources each having

  one of the sets of light sources and each of these

  light source distribution row sembles is

  offset from other sets of repair rows

  tition of adjacent light sources. The gap between

  each of the different distribution rows of sources

  miners and any of the set of distribution rows of adjacent light sources is sufficient

  to allow light emissions from different sources

  these overlap the light emission from at least one other source in the assembly. The light emissions from all the light sources in one of the forms are effective for illuminating the rear lighting surface of the display with a lighting scheme distinguished by the absence of

  total of unlit areas.

  All the light sources are provided on a circuit board with a referential distribution by

  report to the display so that the light emitted by the

  light sources appear directly on the surface

  back lighting side of the display. All of the

  these lights, in one of the forms, further comprises a

  set of photo-emitting diodes. A means is provided for

  riant to diffuse the light emissions of all the light sources and to directly ensure the emission of diffuse light towards the display at its rear lighting surface. The display, in one of the forms, is

a liquid crystal display.

  According to another characteristic, the invention comprises a lighting device intended to illuminate a display from the rear. The lighting device comprises in combination a circuit plate and a set of light sources carried by the circuit plate, the set of light sources generating a lighting scheme illuminating the rear lighting surface of the display and the 'together

  light sources are distributed so that the

  materials thus generated arriving on the rear lighting surface

  of the display is distinguished by a primary absence

  total of unlit areas.

  All the light sources are distributed, according to one characteristic, in a set of rows

  each having a set of light sources and the different

  rents rows of light sources are staggered

  compared to others. The gap between the sets remains

  pective of rows of light sources and adjacent rows

  centes is preferably sufficient to allow the light emissions from each of the light sources in the assembly to overlap the light emissions by at least

  another light source from the set.

  According to another characteristic, the invention relates to a lighting device intended to back light a display comprising a circuit board and a set of light sources on the circuit board;

  the set of light sources illuminates a light surface

  rage from the rear of the display and all the light sources are distributed so that the light emissions from at least one of the light sources overlap the emissions

  from at least one other light source.

  The set of light sources is distributed in several rows each formed by a respective number of light sources and at least one of the sets of rows of light sources is offset with respect to any

  what other row of adjacent light sources.

  According to a preferred embodiment, each of the sets of rows of light sources is offset with respect to any other row of adjacent light sources. The offset between at least one set of rows of light sources and any other set of rows of adjacent light sources is sufficient to

  that the light pattern generated by all of the sources read

  leafminers falling on the rear lighting surface of the af-

  file is distinguished by a significant absence of zones

  unlit. Light emissions from each of the sets

  Light sources preferably overlap the light emissions of at least one other set of light sources. According to another advantageous characteristic, the invention relates to a fuel distribution system

  including a fuel distribution system for

  intended to actively supply fuel in connection with a vehicle tank filling operation and

  a display for operationally displaying information

  for the tank filling operation of the

  vehicle; this display includes a crystal display

  quides, a circuit board, a set of light sources

  ners distributed on the circuit board according to a configuration

  network, all light sources illuminating

  the rear illumination area of the liquid crystal display

  quides; the network configuration of all the light sources is characterized by at least one distribution of

  light sources comprising one of the light source sets

  miners, arranged offset from at least one other distribution comprising other light sources

from the whole.

  The resonance configuration in light sources

  miners is defined in a form by a set of rows each having a set of light sources and

  each of the rows of light sources offset by relative

  port to each other row of adjacent light sources.

  The offset between the respective rows of light sources

  ses is preferably sufficient to allow the light emissions from each of the sets of light sources to overlap the light emissions from at least one other of the light sources. The light emissions of the whole

  light sources are effective in the form of a

  reading to illuminate the lighting surface from the rear of the liquid crystal display with a light path characterized by an almost total absence of unlit areas. All the light sources are arranged on

  the circuit board preferably being distributed relative to

  port to liquid crystal display for emissions

  of all light sources arrive di-

  directly on the back lighting surface of the display

  or liquid crystal display. All the sources read

  miners according to one embodiment further comprises a

  set of photo-emitting diodes.

  One of the advantages of the invention is that the dis-

  positive lighting effectively generates a practically uniform light pattern which arrives on the rear lighting surface of the LCD display and which is distinguished by the absence

  light points (i.e. mini-lighting zones

mum) and unlit areas.

  - Another advantage of the invention is that the sché-

  my lighting can be selectively formed by the appropriate staggering and spacing of the LED diodes to allow the development of a more uniform illumination of the rear surface of the LCD display compared to distributions

classic tions.

  Another advantage of the invention is that the emissions from the LED diodes can be projected directly onto the LCD assembly, avoiding the use of

  reflectors like those that exist in conventional systems

sics.

  Another advantage of the invention is that the dis-

  positive lighting can be achieved with a lower number

  LED diodes while providing the same lighting as

  classic stages, optimally realizing the structure

  LED diodes by an appropriate selection of

  different parameters such as the particular shape of the deca-

  the distance between the different rows of LEDs, the radius and

  the angle of the light emitted, the separation in space

  be the LED diode array and the illuminated surface

  rière LCD as well as the separation in space between the

  different LEDs and rows of LEDs.

Summary description of the drawings.

  The present invention will be described below from

  in more detail using exemplary embodiments

  shown schematically in the accompanying drawings in the-

which:

  - Figure 1 is a perspective view from above of a dis-

  positive lighting according to an embodiment of the present invention,

  - Figure 2 is a top plan view of the light scheme

  neux generated by a group not representative of LED diodes

  of the lighting device according to FIG. 1 to explain

  ter how to overlap between broadcasts

  LED diode annuities according to a characteristic of the present invention, - Figure 3 is a top view of the lighting scheme generated by a group not representative of LED diodes by the lighting device shown in Figure 1 to illustrate a condition d minimal interference between

  emissions of the different LED diodes in another way

  of the present invention, - Figure 4 is a side elevational view showing the emissions of two representative LED diodes in the same row of the LED array for the lighting device of Figure 1, - Figure 5 is a diagram of a representative assembly of

  LED diodes of an LED network according to Figure 1 for explanation-

  ter the necessary separation between the photo-

  emissive to have a circular light output diagram

laire on 360.

  - Figure 6A is a plan view of the general lighting scheme

  created by a representative group of LED diodes from

  shot from the assembly of figure 3 to illustrate the criteria

  LED matrix design that will allow the development

  development of such a light scheme, - Figure 6B is a plan view of the light scheme generated by the representative group of LED diodes according to another form of LED assembly for the lighting device of Figure 1 associated with a condition d 'interference

  according to a characteristic of the present invention

  tion and illustrating the design criteria of a ma-

  LED diode to develop such a light scheme, - Figure 7 is an exploded view of a liquid crystal display showing how to provide lighting by

  the back of an LCD display with the lighting device

  Figure 1 rage, - Figure 8 is a block diagram showing a system of

  fuel distribution using the lighting device

  rabies of Figure 1, according to another embodiment of

the present invention.

  - In the drawings, the same references will be used in the different figures. The examples developed below

  are illustrations of a preferred embodiment

  tiel of the invention in some form, without limiting

  the scope of the invention. Detailed description of the invention.

  According to the drawings, and in particular according to the

  gure 1, there is a perspective view from above of a lighting assembly 10 composed of several light sources carrying

  as a whole, the reference 12 on a circuit board 14 intended to illuminate the rear lighting surface of a display such as a liquid crystal display according to an embodiment of the invention.

  Figure 2 is a top view of the lighting scheme created by a representative group of sources

  of the lighting device 10, to show the

  emission of different light sources

  neighbors according to a feature of the present invention.

  As will be discussed in more detail below,

  all the light sources 12 are preferably distributed

  ti according to a network or a matrix configuration with

  adjacent rows of light sources, arranged in fifteen

  designed or offset from each other.

  The lighting diagram shown in Figure 2 shows a

  form of such an offset distribution and separation spa-

  corresponding between the different LEDs and

  the rows of LED diodes, to facilitate the presentation of the overlap between the light emissions generated by the different light sources. These light sources 12 are preferably photo-emissive diodes (LEDs). Referring briefly to Figure 7 we see the device

  10 according to FIG. 1 which preferably makes

  differential, part of a display system 16 for lighting

  the rear lighting surface of a liquid crystal display

  quides 18 as will be detailed below.

  According to FIG. 1, all of the light sources

  neuses 12, shown on the circuit board 14, is distributed

  ti in a network or array configuration (hereinafter called

  after LED network) defined according to an exemplary embodiment by

  a set of discrete rows each having a distribution

  respective tion of light emitting diodes. The golden way-

  ganizing the LED array 12 is preferably chosen so that each row of LED diodes is offset (staggered) relative to the other rows of adjacent LED diodes. For example, the distribution of LED diodes as shown for the 2nd row is offset from the distribution of LED diodes of the 1st and 3rd adjacent rows. According to one

  preferred form, individual LED diodes are deca-

  linked in an equivalent alternate manner. The matrix configuration as shown is given by way of example and does not constitute a limitation to the present invention; he

  It is clear that other standard distributions may be around

  in the context of the present invention. In addition, the

  number of photo-emissive diodes presented corresponds only-

  by way of example and any other number of light sources

neuses is possible.

  As described, the use of a network or a matrix to define the organization of all the diodes

  photo-emissive 12 should be understood to include no

  carries what ordered or random distribution or disposition

  LED diodes on a circuit board 14, appropriately

  required according to the development of the desired light emissions

  tees to illuminate the destination structure, usually the

  rear lighting surface of a liquid crystal display

  of. The choice of a distribution of particular LED diodes

  can be done taking into account factors such as deter-

  mination of the adequate relationship and / or interaction between the emanations of the various LEDs to generate a desired lighting scheme. To this end, the array of LED diodes 12 preferably takes the form shown in FIG. 1

  in which the different rows of LED diodes are de-

  wedged and spaced from each other by a ma-

  sufficient to create a desired overlap between the different LEDs as shown in Figure 2. Alternatively, the offset and spacing between the different

  LEDs and between discrete rows can be chosen

  located to create different lighting schemes like those shown in the different views of Figure 3 and in] l Figures 6A-6B corresponding to other distributions of

LED diodes.

  It is clear that the offset presented in FIG. 1 corresponds only to an example and should not be considered as a limitation of the present invention since other forms of offset are possible within the scope of the present invention following the type of light pattern that

  we wish to generate with the network of LED diodes 12.

  By way of example, it will be examined below, in conjunction with FIG. 2, how to choose the offset for

  generate a compound light pattern characterized by an ab-

  significant sence of unlit areas, namely developing

  causing an overlap between the light emissions of each LED and the light emissions of each nearest neighboring LED in the same row and in

  any row directly adjacent. This scheme of

  lighting gives more uniformity to the distribution of information

  light density in its coverage of the surface, compared

  use of the classic lighting scheme comprising inappropriate lighting zones and dark spots mixed with lighting zones. Although the type of offset presented

  in the drawings gives a gap between the different ran-

  distribution diodes of LED diodes, this description is not

  given only as an example since the use of offset or displacement as described must be considered to include any type of spacing between any

  which LEDs without necessarily being limited to deca-

* staggered row between two rows. For example, while each row of LEDs can be offset from the other row, the distribution of LEDs in the same

  row can be done in different subgroups in the-

  which each time there is a scaling relation.

  The expression "circuit board" used in

  the description should be considered to include any

  what structure or training that provides a

  LED diode bucket 12 and which includes, without limitation, a substrate, a generally planar structure which receives in itself the LED diodes, a platform intended to hold the LED diodes and an integrated circuit plate which includes other components in addition to the network of LED diodes 12. In

  in addition, the circuit board may include the diode network

  LEDs 12 alone or in combination with other devices such as an integrated circuit configuration. The wiring and the power source of the LED diodes can be on the plate or be ensured by any known means

specialists.

  The expression "light source" used here should be understood to include any device, component, or other structure capable of emitting

  electromagnetic energy, preferably or in an ap-

  suitable for back lighting. So the e-

  light energy preferably corresponds to the visible spectrum although other spectral zones can be used in particular applications. The light source includes

  non-limiting manner of the photo-emissive diodes. The differ-

  LED diodes can be of any suitable type

  required such as T1 or surface mount diodes.

  According to Figure 2 there is a top view of the dryer

  my luminous generated by a grouping representative of the LED diodes of the rows 1-3 of the network of LED diodes 12 of the figure

  1, offset according to a characteristic of the present invention

  tion to give an overlapping lighting scheme.

  The LEDs are distributed so that the light emissions

  its from each of the different overlapping photo-emissive diodes

  the light emissions of the various other photoemissive diodes of the LED network 12. In particular, the light

  emitted by the representative diode LED, 20 of row 2 che-

  the light emitted by the LED diodes directly adjacent

  centers in the same row (i.e. LEDs 34, 36); this light also overlaps the light emitted by the LEDs closest to the adjacent row,

  i.e. LEDs 22, 24 in row 1 and the diodes

  26, 28 of row 2. This form of overlap, when performed for the entire array of LED diodes 12, develops a pattern of compound, incident light, on the rear lighting surface of the display (usually a liquid crystal display); this scheme is characterized by the almost total absence of unlit areas. The net result of this overlap is the creation of a scheme

  more uniform lighting than conventional lighting schemes with multiple black dots (i.e. areas not

  illuminated) and bright spots (usually

  minimal lighting surfaces). The overlap removes ef-

  effectively all these light points and these non-illuminated areas

  otherwise exist in the lighting

  generated by classic light distributions.

  FIG. 3 shows a lighting diagram generated by a representative group of LED diodes corresponding to a

  variant of distribution of LED diode network 12; this sche-

  ma is characterized by minimal interference between the light emanations from each LED and the light emanations from adjacent LEDs in the same row as well as the adjacent LEDs, which are adjacent to the nearest row. The lighting scheme contrasts with that of the

  Figure 2 in that the emissions from each LED diode overlap

  See adjacent LED diodes in the same row and diodes

  adjacent LEDs adjacent to the nearest row. This particular lighting scheme does not include a hot spot because of the significant absence of overlap between the

  emissions from the different LEDs. As noted, the

  appears from the array of LED diodes 12, the distribution of the LED diodes 12 presented in a representative manner in FIG. 3 results in that each LED diode can generate a circular output lighting scheme over practically 3600. A

  further examination of this arrangement is described in relation to the fi-

gure 6A.

  According to Figure 4, there is shown, for purposes

  analysis, a schematic side view of the light emissions

  its as an example coming from two LED diodes 30, 32 ad-

  adjacent, belonging to the same row of an array of LED diodes 12. This diagram shows in particular the relationship between the design parameters p (angle of light emission by the

  LED diode, i.e. the viewing angle); h (the height separa-

  the LED diode array 12 and the illuminated surface

  laugh that is illuminated; w (the distance between the LEDs in the same row). Using classical trigonometry we obtain the following formulas: tan a = (w / 2) / h. The half

  angle a is equal to p / 2 so that the equation gives the rela-

  next tion: w = 2h * tan (ç / 2). FIG. 5 shows, for analysis, a schematic top view of a distribution of LED diodes with offset rows to illustrate the spatial separation D necessary between the adjacent rows to give an output diagram

  circular on 360 for each LED diode. This pattern of exit

  tie is presented for example for the LED network in figure

  3. A condition of such a fully circulating output scheme

  the word is that each respective LED is separated from the adjacent LEDs of the same row and from each of the neighboring LEDs, the closest to the adjacent row by at least the distance "w", the meaning of which is given in Figure 4 For example, the representative LED 20, is separated from the LEDs 34 and 36 of the same row by a distance "w" as well as by the distance "w" relative to each of the neighboring LEDs 22, 24 the closer and diodes 26, 28 of the adjacent rows. Using classical trigonometry we establish the following relation:

2 2 (1/2)

  D = (w w / 4) Figures 6A and 6B show, for the analysis,

  a pair of schematic top views representing the mo-

  lighting elements associated respectively with a condition

  minimum interference and a maximum interference condition

  mum for the light pattern arriving on the light surface

  rear rage of the LCD display. These

  diagrams facilitate the determination of the values of the separation

  spatial division between adjacent LEDs in the same row and the spatial separation between adjacent rows

  to give the interference conditions set out above.

  These views each show, for the distribution of the LEDs, the illumination diagram at height "h" above the

  LED diodes referenced in connection with Figure 4.

  Referring first to FIG. 6A, it can be seen that the use of trigonometry leads to the following expressions for w (the distance which separates the LEDs from the same row) and D (the distance which separates from the rows

2 2 (1/2)

  adjacent LEDs): w = 2r and D = (w - w / 4) (/), which is the same expression as that found in connection with Figure 5.

  According to FIG. 6B, by trigonometry, we obtain

  holds the following expressions for w '(the distance separating the LED diodes of a same row) and D' (the distance separating rows of adjacent LED diodes): w '= 2r * cos (30) and D' = [r + r * sin (30)],

  in these formulas, "r" represents the radius of the exit diagram

  circular tie at height "h" above the diode array

LED 12.

  Figure 7 is an exploded perspective view

  a display system 16 comprising a set of lights

  rage 10 appropriately arranged to provide light

  rear rage of the set 18 of the liquid crystal display

  quides (LCD) according to another embodiment of the

  vention. The LCD assembly as shown 18 comprises, according to an example, an LCD graphic display 38, an LCD display with

  7 segments 40 and another display 42; these different affi-

  cheurs are of classical construction. To illuminate this world

  tage of LCD structure the lighting assembly 10 is used in the form presented, comprising a network of first LEDs 44 to illuminate the graphic display LCD 38 and a second network of LEDs 46 to light the LCD display 7 segments as well as the display structure 42. The

  first and second arrays of LED diodes 42, 44 such as re-

  shown each have a respective set of diodes

  discrete LEDs distributed on a circuit board 14 and rea

  read according to the principles of the present invention, given above in the case of the LED array 12, according to FIGS. 1 to

  6 to facilitate correct lighting of the structures

LCD liquid rates.

  The assembly indicated for the LCD assembly 18 is only given by way of example and specialists will know that the LCD assembly 18 can be provided in different forms capable of being illuminated at their rear lighting surface, with the appropriate configuration of

  the lighting assembly 10, namely by selecting the con-

  adequate LED network representation. In addition, the LCD assembly 18 can be produced in the integrated form of FIG. 7 or in the form of a set of assembly of separate LCD panels.

  For operation, the first network of dio-

  LEDs 44 and the second array of LEDs 46 are activated

  each in a conventional manner to generate light emissions

  neuses according to respective patterns which arrive on the

  rear lighting face of the LCD assembly 18, namely the respective lower surface of the LCD graphic display 38, of the 7-segment LCD display 40 and of the display structure 42. The LED diodes of the first and from the second network

  LED diodes 42, 44 can be activated in a controlled manner

  Dedicated and selective by a programmable controller (not shown

  sensed), provided in the form of dedicated wiring or a microprocessor intended to connect the LED diodes by

  conventional means. Other known variants of specialties

  your can be used to activate the first and second

set of LED diodes 42, 44.

  According to another characteristic of the present invention shown in Figure 7, the lighting assembly is appropriately placed in a location and with an orientation relative to the LCD assembly 18 so that the rear lighting is done by transmission direct light emissions from the lighting assembly 10 to the lower surface of the LCD assembly 18. This propagation

  differs from other light sources

  stages in which there is, in the intermediate position, a reflector structure which returns the light emissions to effect an indirect projection of light on the

  LCD rear surface. As described, the expressions "propa-

  direct gation "and" direct transmission "are used interchangeably and must be understood with

  other equivalent expressions such as encompassing communication

  cation of light between the lighting assemblies 10 and the rear lighting surface of the LCD assembly 18 along a propagation path that is practically without reflection. For it,

  the first and second set of LED diodes 42, 44 defi

  preferably create a generally planar configuration located at a distance and generally parallel and behind the rear lighting surfaces, associated with

  the LCD assembly 18 so that the LED arrays 42, 44 produce

  feels emissions in concordance for lighting in direct light with their respective rear lighting surface of the LCD assembly 18. However, it is clear that the present

  invention also allows other variants with a struc-

  A reflector structure suitably interposed between the lighting assembly 10 and the LCD assembly 18 to return the light emissions from the LEDs on the rear LCD lighting surface. The integration of such a reflector structure does not interfere or limit the functional character or the effectiveness of all the characteristics of the present invention, in particular the development of a

  appropriate lighting scheme as described above in use

  the proper offset and spacing of the LED diodes to

  create an appropriate overlap of light emissions, avoid-

  both for example the appearance of lighting points and

unlit surfaces.

  Figure 8 shows a block diagram of an ins-

  fuel distribution plant 50 with a dispensing device 52 connected to an interactive display module 54 comprising a lighting device 10 according to FIGS. 1 to 7 corresponding to another embodiment of the present invention. The fuel dispenser 52 is of conventional construction and generally works to

  supply fuel as part of a tank refill

  view of vehicle. The display module 54 includes a display

  liquid crystal cleaner 56 in the service station; this display is analogous to the LCD assembly 18 of FIG. 7; it is illuminated from the rear by a lighting device 10 as described above with reference to Figures 1

  to 7. A touch screen 58, accessible to the user and sus-

  ceptible to be activated by it, allows the operator to submit different requests and issue orders to the fuel dispenser 52 through the

control circuit 60.

  These instructions and orders relate to the tank filling operation. The signals from the touch screen 58 are supplied to the lighting device 10 in an appropriate format to allow the selective activation of the associated LED networks so that the user's orders, the responses of the controller of this petrol station and / or the other characteristic information is displayed for the operator in the LCD station 56. The touch screen 58 can be produced by other means which actuate the elements

  LEDs and thus generate the rear lighting of the LCD screen 56.

  The characteristic shape and the way of integrating the lighting device 10 into the fuel distribution system 50 are not limited to the embodiment of FIG. 8; it is clear that this realization may include

  other assemblies in addition to other types of distribution systems

  fuel contribution. In addition, although the lighting device 10 according to the present invention is integrated into a fuel distribution system according to one embodiment

  preferential, the invention is not limited to this application.

  cation and can be extended to other applications that require

both the lighting of a surface.

  Alternatively, the lighting of the

  board to complete the organization with LEDs of type re-

  bucket, shown in Figures 1 to 7; in this montage the

  LED diode bucket is located at least partially in the interior space of the circuit board 14. In addition, a structure

  semi-opaque diffuser may be interposed between the

  lighting sitive 10 and the LCD assembly 18 to diffuse the emissions from the LED diodes and provide the diffused light to the

  rear surface of the LCD assembly 18. The broadcasting activity

  sion corresponds to the direct propagation of light from the LED diode networks to the LCD rear lighting surface.

  The strategy to be adopted according to the present invention

  tion to illuminate the rear lighting surface of a

  display structure (usually a crystal display

  quides) consists in providing a set of photo-diodes

  emitting as a light source and to distribute this set of LEDs in a suitable way to develop a

  appropriate lighting scheme arriving on the lighting surface

  rear rage. For example by distributing all the LEDs in a network configuration with an offset

  between the respective LEDs (generally between the ran-

  adjacent rows there is an offset from one row to the other) and by choosing the distance appropriately

  separating the LED diodes of the same row and the distance se-

  paring the adjacent rows of LED diodes, we obtain a lighting scheme by the LED network. This lighting scheme

  can for example be carried out appropriately to give

  ner an overlap between the light emissions of the diff

  different LEDs and create a compound lighting scheme, characterized by the almost total absence of black dots

  and minimizing the illuminated areas which, by

  parison, appear in the classic lighting diagrams

  ques. This overlap facilitates the creation of lighting

  rear more evenly distributed and more evenly distributed

  compared to conventional lighting schemes

  which are distinguished by a nesting of unlit surfaces

  areas and dimly lit areas with regions

sufficient lighting.

  The various factors can be taken into account to determine the particular shape of the array of LED diodes including without limitation the type of LED diode used, the angle and the radius of the light emitted by each LED diode, the separation in the space between the

  LED diode array and LCD panel, extension and de-

  desired degree of overlap (or non-interference) between the different emissions of LED diodes, spatial separation

  between the LEDs, the spatial separation between the groups

  pes of individual networks (in general the rows of LED diodes), the desired density (which depends on the radius and the angle of

  the light emitted) and the desired clarity (which depends on the

  light intensity of the LEDs). Clear,

  certain factors influence the choice of other parameters.

  Manipulating these variables to arrive at a certain degree of nesting can, for example, allow the manufacturer to actually reduce the necessary number of LED diodes without this being to the detriment of the quality of the lighting. For example, the offset can be confused to give a certain lighting power by requiring fewer LEDs

  than an unstaged distribution. This advantage can be attributed to the light interference characteristics accompanying the overlapping of the light emission patterns by the LEDs.

Claims (26)

R E V E N D I C A T I ON S   1) Lighting device intended for a rear-lit display, this lighting device comprising: - a circuit board (14), - a set of light sources distributed over the circuit board according to a network configuration, this set of light sources being intended to illuminate the rear lighting surface of the display, characterized in that   the network configuration of all light sources   ses has at least one distribution of light sources including certain light sources, offset from   at least another distribution of light sources including   taking other light sources.   2) Device according to claim 1, characterized in that the light emitted by at least one of the sets of light sources overlaps the light emitted by at least one of   other sets of light sources.   3) Device according to claim 2, characterized in that the offset between at least one assembly of light sources   and at least one other mounting of light sources is sufficient   health to at least partially ensure the overlap of the lights emitted by at least one of the sets of sources with the light emitted by at least one of the other sets sources.   4) Device according to claim 3, characterized in that   the network configuration of all light sources   ses is defined by a set of light source distribution rows, each corresponding respectively to   one of multiple light sources and each of the   appears rows of light source distribution being offset from any of the other sets   rows of adjacent light sources.    ) Device according to claim 4, characterized in that the offset between each of the sets of rows of light sources and any other set of rows of distribution of adjacent light sources is sufficient to allow the light emitted by each of the sets light sources overlap the light emitted by at   minus one of the sets of light sources.   6) Device according to claim 5, characterized in that the light emitted by all of the light sources is   intended to illuminate the rear lighting surface of the af-   file with a light pattern characterized by an absence noticeable in unlit areas.   7) Device according to claim 4, characterized in that all of the light sources is arranged on the circuit board to be positioned relative to the display of   so that the light emitted by all light sources   neuses propagates directly towards the ar- of this display.   8) Lighting device according to claim 7, characterized in that all of the light sources further comprises:   - a set of photo-emitting diodes.   9) Lighting device according to claim 7, characterized in that it further comprises:   - a means of broadcasting light emissions from the   looks like light sources and to directly ensure   the light emission diffused towards the display of the rear lighting side.    ) Device according to claim 8, characterized in that the display further comprises:   - a liquid crystal display.   11) Device according to claim 1, characterized in that   the network configuration of all light sources   ses is defined by a set of mounting rows of light sources, each comprising a respective one of the set of light sources and each respective of the set of mounting rows of light sources being offset one with respect to the other of all rows   for mounting adjacent light sources.   12) Device according to claim 11, characterized in that   the offset between each of the respective distribution rows   tion of light sources and each of the sets of rows   distribution of light sources is sufficient to   set the light emission from these sources to illuminate the rear lighting surface of the display according to a light pattern which is distinguished by the practically total absence unlit areas.   13) Device according to claim 12, characterized in that the light emissions from each of the different light sources overlap the light emissions by at least   another of the different light sources.   14) Device according to claim 13, characterized in that all of the light sources as placed on the circuit board is distributed relative to the display so that the light from this set of light sources is propagated   directly to the rear lighting surface of the af-   fileer. ) Device according to claim 1, characterized in that   the offset between at least one distribution of light sources   and at least one other distribution of light sources   ses is sufficient to allow light emissions to illuminate the rear lighting surface of the display with   a light scheme which is distinguished by the practical absence-   total of unlit areas.   160) Device according to claim 15, characterized in that the light emissions from each of the different light sources of the assemblies overlap the light emissions   at least one other source from one of the light sources.   17) Device according to claim 16, characterized in that   the network configuration of all the light sources   neuse is defined by a set of rows each having   light sources and each of the rows of light sources   leafminers is offset from the neighboring row of sour- these adjacent lights.   18) Device according to claim 1, characterized in that all of the light sources are distributed over the circuit board while being distributed relative to the display so that the light emitted by all of the light sources comes directly to the rear lighting area of the display.   19) Device according to claim 18, characterized in that   the offset between at least one distribution of light sources   and at least one other distribution of light sources   its is sufficient to allow the light emissions from each of the different light sources to overlap the   light emissions from at least one other light source.    ) Lighting device intended to illuminate a display from the rear, characterized in that it comprises: - a circuit board - a set of light sources provided on the circuit board, these different light sources being used to generate a light pattern illuminating the rear lighting surface of the display, - all the light sources are distributed so that   the light pattern generated arriving on the light surface   rear rage of the display is distinguished by an absence   practically total of unlit areas.   21) Device according to claim 20, characterized in that   all the light sources are distributed according to more   seir rows each formed from a set of light sources   and each row is offset from any other row in the two-row set adjacent light sources.   22) Device according to claim 21, characterized in that the offset between one of the sets of rows of light sources and the adjacent one of this set is sufficient   to allow light emissions from each of the sources   these respective bright of the whole overlap the   light emissions from at least one other light source.   23) Lighting device intended to backlight a display, this lighting device comprising: - a circuit board,   - a set of light sources on the circuit board   cooked, this set of light sources being intended to illuminate the rear lighting surface of the display, - the set of light sources being distributed so that   light emissions from at least one of the sources   miners overlap light emissions by at least another of the light sources.   24) Device according to claim 23, characterized in that   all the light sources are distributed according to more   their rows each formed of a set of light sources neuses,   - at least one of the rows of light sources being de-   set relative to each other sets of rows of adjacent light sources.    ) Device according to claim 24, characterized in that   the staged relationship between at least one of the sets of ran-   light sources and at least one other set of rows of adjacent light sources is sufficient to   that the light pattern generated by all of the sources read   miners arriving on the rear lighting surface of the display is distinguished by an almost total absence areas without light.   26) Device according to claim 25, characterized in that the light emissions from each of the different light sources overlap the light emissions by at least another light source.   27) Device according to claim 26, characterized in that   each of the sets of rows of light sources is de-   calibrated against any other row of sources adjacent lights.   28) Fuel dispensing system comprising - a fuel dispensing installation intended to actively supply fuel in connection with a vehicle tank filling operation and   - a display for operationally displaying information   concerning the vehicle tank filling operation, with - a liquid crystal display, a circuit board, and - a set of light sources distributed on the circuit board according to a network configuration, all of the   light sources illuminating the rear lighting surface   of the liquid crystal display,   - the network configuration of all the light sources   neuses being characterized by at least one distribution of light sources comprising certain light sources, arranged in a manner offset from at least one other distribution comprising other light sources of the set.   29) Fuel distribution system according to the claim tion 28, characterized in that   the network configuration of all light sources   ses is defined by several rows each having a set of   ble of light sources and each of the sets of rows   of light sources is offset from any   which of the sets of rows of adjacent light sources   your. ) System according to claim 29, characterized in that the offset between each of the sets of respective rows of light sources and any of the sets of rows of adjacent light sources is sufficient to   allow the light emissions from each set respec-   tif among sets of overlapping light sources   light emissions from at least one other light source neuse of the whole.   31) System according to claim 30, characterized in that the light emissions from the set of light sources make it possible to eliminate the rear lighting surface of the liquid crystal display according to a lighting scheme distinguished by the practically total absence of unlit areas. 32) System according to claim 29, characterized in that   all the light sources as placed on the plate   that the circuit is distributed with respect to the display   liquid rates so that the light emissions of the whole   light sources propagate directly towards the   back lighting side of the liquid crystal display.   330) System according to claim 30, characterized in that the set of light sources further comprises:   - a set of photo-emitting diodes.