WO2008145250A1

WO2008145250A1 - Liquid crystal display field

Info

Publication number: WO2008145250A1
Application number: PCT/EP2008/003796
Authority: WO
Inventors: Georg Diamantidis; Frederic Tonhofer
Original assignee: Noctron Soparfi S.A.
Priority date: 2007-05-31
Filing date: 2008-05-10
Publication date: 2008-12-04
Also published as: CN101315490B; DE102007025573A1; CN101315490A; EP2158507A1

Abstract

Specified is a liquid crystal display field comprising a liquid crystal panel (12) with a flat viewing face (14) and a large number of drivable liquid crystal cells (18). An illumination device (26), which is designed such that light emitted by the illumination device (26) illuminates the liquid crystal panel (12) on that face (16) which is remote from the viewing face (14), can be used to produce optionally at least light of a first colour, light of a second colour and light of a third colour.

Description

Liquid crystal display panel

The invention relates to a liquid crystal display panel according to the preamble of claim 1.

Such liquid crystal display panels, or liquid crystal screens commonly known as LCD screens, are becoming increasingly popular because of their flat design.

Various techniques for producing color images by means of LCD screens are known. For example, each pixel on the liquid crystal panel can be constructed of three juxtaposed liquid crystal cells, each of which individually represents the color information of the corresponding red, green and blue pixel. The superposition of the light emitted by these three juxtaposed liquid crystal cells results in the total color information of the individual pixel. The overall picture is composed accordingly of a plurality of such pixels shown.

The illumination device emits white light, with which the liquid crystal panel is illuminated areally from its rear side. In order for each liquid crystal cell to reproduce the color assigned to it, a color mask is provided, which must be adapted correspondingly with high precision to the arrangement of the individual liquid crystal cells.

However, such LCD screens are structurally and control technically very expensive, which is why LCD screens, and in particular large-scale LCD screens with high resolution, are relatively expensive. -? -

The object of the invention is therefore to provide a liquid crystal display panel of the type mentioned, which is simpler in structure and whose control is less expensive.

This object is achieved by a liquid crystal display panel having the features specified in claim 1.

Characterized in that by the illumination device optionally at least light of a first color, light of a second

Color and light of a third color, preferably red, green and blue, can be generated, can be dispensed with the mentioned color mask. Also, not every pixel needs to be formed by three juxtaposed liquid crystal cells. Rather, each liquid crystal cell of the liquid crystal panel can represent a pixel of the image to be formed, whereby the resolution can be increased accordingly with the same number of liquid crystal cells.

The color information for a pixel perceptible to the viewer of the liquid crystal display panel can be generated by rapidly adjusting the corresponding liquid crystal cell to a redness transmission value, a green component transmission value, and a blue component transmission value , Corresponding to this sequence, the lighting device is in each case controlled so that it emits red light, green light or blue light at the appropriate time.

Advantageous developments are specified in the dependent claims.

By the measure according to claim 2, three separate _ ^ _^

Light sources are controlled separately, reducing the risk of color interference is reduced.

In order to produce a naturally appearing color image, it is favorable if the lighting means can emit light in the wavelength ranges specified in claim 3.

Advantageously, the lighting means are designed as specified in claim 4. Semiconductor luminescent chips combine high luminosity with low energy consumption and a long service life. In addition, semiconductor light emitting chips advantageously have short response times, i. Semiconductor luminescent chips emit light within a very short time when voltage is applied without having to go through a significant start-up phase. Furthermore, semiconductor luminescent chips do not light up when the voltage application is terminated. Due to these characteristics of semiconductor light emitting chips, the required fast sequence of single color images can be conveniently achieved.

Alternatively, one or more of the lighting means may be formed as indicated in claim 5. The respective primary color of the semiconductor luminescent chips does not have to match the desired first, second or third color of the first, second or third luminescent means. The wavelength of the light emitted from the semiconductor light-emitting chip can be adjusted by the phosphor particles. Phosphor particles absorb incident light from a primary color and emit radiation at least at a different wavelength, ie at a secondary color. With a suitable choice of phosphor particles or phosphor particle mixtures, therefore, the radiation emitted by the respective semiconductor luminescent chip can be converted into radiation with a different spectrum. A uniform illumination of the liquid crystal panel is achieved by the measure according to claim 6.

The measure according to claim 7 ensures that the thickness of the lighting device is not influenced by the arrangement of the lighting means.

It is advantageous as far as the coupling of the light into the plate-shaped light guide element is concerned, if the

Illuminants are arranged, as indicated in the claims 8, 9 and 10.

In order to increase the proportion of the light emitted by the light bulbs, which is coupled into the plate-shaped light guide element, the measure according to claim 11 is advantageous.

The measures according to claims 12 and 13, a good light transmission from the light sources is achieved on the plate-shaped light guide element.

In order to increase the luminous efficacy of the light emitted by the illumination device via its first main surface, the measure according to claim 14 is favorable. It is advantageous if the reflection device is designed according to one of claims 15 to 18. A strong reflection ^¬ effect is achieved in particular by the measures according to claim 16 and / or claim 17.

For the paper sheet according to claim 18, basis weights have proved favorable, as indicated in claim 19.

To reduce the loss of light from the reflection device is reflected in the direction of the second main surface of the plate-shaped optical waveguide element due to a reflection on this second main surface of the plate-shaped light guide element itself as low as possible, the second main surface of the plate-shaped light guide element is advantageously formed as specified in claim 20 ,

The plate-shaped light guide element preferably consists of one of the materials mentioned in claim 21.

In order to obtain a high luminosity of the illumination device, this can be advantageously designed as specified in claims 22 or 23.

Embodiments of the invention are explained below with reference to the drawings. In these show:

FIG. 1 is a plan view, partly broken away, of a first embodiment of a liquid crystal

Display panel;

Figure 2 is a section through the liquid crystal display panel of Figure 1 along the section line II-II;

Figure 3 is a partially broken away plan view of a second embodiment of a liquid crystal display panel, ^•

Figure 4 is a section through the liquid crystal display panel of Figure 3 along the section line IV-IV there;

Figure 5 is a Figures 2 and 4 corresponding section by a third embodiment of a liquid crystal display panel;

Figure 6 is a partially broken plan view of a fourth embodiment of a liquid crystal display panel;

Figure 7 is a section through the liquid crystal display panel of Figure 6 along the section line VII-VII there; and

Figure 8 is a section corresponding to Figure 7 through a fifth embodiment of a liquid crystal display panel.

In FIGS. 1 and 2, a liquid crystal display panel 10 is shown which comprises a liquid crystal panel 12 having a flat viewing side 14 and a flat rear side 16 remote therefrom (see FIG. 2). The liquid crystal panel 12 comprises a plurality of liquid crystal cells 18, as known per se, of which only five liquid crystal cells are shown schematically in FIG.

The liquid crystal cells 18 may be, for example, TFT cells each comprising a capacitor and a thin film transistor. But all other known techniques with respect to liquid crystal cells are suitable. The liquid crystal panel 12 may be rigid or flexible.

A control unit 20 comprises a processor (not specifically shown) and calculates from image signals which it receives via an input line 22, which liquid crystal cells 18 are switched to display the corresponding image. have to. The liquid crystal cells 18 in question are then driven by the control unit 20 via control lines 24.

In order for the liquid-crystal display panel 10 to display a color image and not just a black-and-white image, a lighting device 26 is provided which is arranged on the rear side 16 of the liquid crystal panel 12 and illuminates it from its rear side 16.

The illumination device 26 includes a light guide plate 28. The light guide plate 28 may be made of transparent acrylic glass or other homogeneously transparent material, such as a glass or an epoxy resin. The light guide plate 28 is preferably clear. The light guide plate 28 can also be made of a flexible, homogeneously transparent material, in particular if the Flussigkristall- panel 12 is flexible.

The light guide plate 28 has a first main surface 30, over which useful light generated by the illumination device 26 is emitted. On the opposite side, the light guide plate 28 has a second main surface 32 (cf., FIG. 2) which has a surface roughness indicated by teeth, which will be discussed in greater detail below.

On two opposite outer edges 34 and 36 carries the light guide plate 28 each have a light bar 38 a and 38 b. The light strips 38a and 38b are explained below only by the example of the light bar 38a closer. The statements apply mutatis mutandis corresponding to the light bar 38b. - -

The light strip 38a comprises a housing 40 with a U-shaped cross section and here not specifically provided with a reference numeral end walls. The respective open side of the housing 40 points in the direction of the correspondingly adjacent outer edge 34 or 36 of the light guide plate 28.

The housing 40 delimits with the outer edge 34 of the optical waveguide plate 28 an interior 42 in which three types of light sources in the form of semiconductor luminescent chips 44, semiconductor luminescent chips 46 and semiconductor luminescent chips 48 are arranged.

When exposed to voltage, the semiconductor luminescent chips 44 emit red light in a wavelength range of about 630 nm to about 670 nm. As semiconductor materials for the semiconductor luminescent chips 44 for the color red, for example, aluminum gallium arsenide (AlGaAs), gallium aluminum arsenide (GaAlAs) or Gallium arsenide phosphide (GaAsP) in question.

When exposed to voltage, the semiconductor light-emitting chips 46 emit green light in a wavelength range from approximately 540 nm to approximately 600 nm. Suitable semiconductor materials for the semiconductor light-emitting chips 46 for the color green are, for example, gallium phosphide (GaP).

The semiconductor light emitting chips 48 emit when exposed to ultraviolet light and blue light in a wavelength range of about 420 nm to about 480 nm. As the semiconductor materials for the semiconductor light emitting chips 46 for the color blue, for example, indium gallium nitride (InGaN) and gallium nitride (GaN) serve.

The semiconductor light-emitting chips 44, 46, 48 may, for example, each have an n-type layer and a p-type Layer of a III-V semiconductor material such as those mentioned above, as it is known per se. Between such an n-type and such a p-type layer, an MQW layer may be disposed. MQW is the abbreviation for "Multiple Quantum Well". An MQW material is a superlattice which has an electronic band structure altered according to the superlattice structure and correspondingly emits light at other wavelengths. By selecting the MQW layer, the spectrum of the radiation emitted by the pn-semiconductor light-emitting chip can be influenced in a targeted manner. The layers mentioned can be carried, for example, by a sapphire substrate, which in turn can be applied to a glass pane or a metal grid.

The semiconductor light-emitting chips 44, 46 and 48 thus form an RGB chipset 50.

The interior 42 of the housing 40 is filled with a light-conducting liquid in the form of liquid silicone oil 52, which is indicated in the figures in the form of circles and light emitted by the semiconductor light-emitting chips 44, 46 and 48 to the outer edge 34 of the light guide plate 28th passes. In addition, heat generated by the semiconductor luminescent chips 44, 46 and 48 is dissipated to the outside by the silicone oil 52, in particular to the walls of the housing 40. The housing 40 is made of metal, for example, whereby a good heat dissipation is supported to the outside.

The semiconductor light-emitting chips 44 are connected in parallel and can be acted upon by two supply lines 54, 56 with voltage, which lead to the control unit 20 and are fed by the ^¬ ser controlled from an energy source, not shown. The semiconductor light-emitting chips 46 are also connected in parallel and via two supply lines 58, 60 can be acted upon by voltage, which lead in the same way to the control unit 20 and are controlled by the power source fed from this. Accordingly, the semiconductor light-emitting chips 48 are connected in parallel. Their voltage is applied via two supply lines 62, 64, which also lead to the control unit 20 and are controlled by the power source fed.

The semiconductor light-emitting chips 44, 46 and 48 can also each be connected in series.

In the section shown in FIG. 2, one of the semiconductor luminescent chips 46 can be seen for the color green. The supply lines 54 to 64 and the control unit 20 are not shown in FIG. 2 for the sake of clarity.

The inner walls of the housing 40 are provided with a reflection layer 66, whereby light, which is emitted from the semiconductor light-emitting chips 44, 46 and 48 in a direction away from the light guide plate 28 direction, is reflected on the same or its outer edge 34.

As can be seen in particular in Figure 2, the light guide plate 28 sits with its second major surface 32 on here not specifically provided with a reference numeral walls of another housing 68 and forms as it were the lid. The housing 68 and the second main surface 32 of the light guide plate 28 thus define an interior space 70.

On the second main surface 32 of the light guide plate 12, a white paper sheet 72 is applied with a layer 74 of a silicone material, which is also shown in the form of circles.

As silicone material comes, for example, a viscous Silicone oil in question. The white paper sheet 72 is impregnated with the viscous silicone oil of the layer 74 before being applied to the light guide plate 28 and then pressed onto the second main surface 32 of the light guide plate 28 with a roller under pressure. In doing so, care must be taken that all the air bubbles possibly present in the silicone oil of the layer 74 and between the paper sheet 72 and the light guide plate 28 are pressed out by the pressure of the roller. The white paper sheet 72 is fixed on the second main surface 32 of the light guide plate 28 by the adhesion action of the silicone oil of the layer 74.

Instead of thick silicone oil, the layer 74 may also be made of a viscous elastic silicone compound 74. For this purpose, the paper sheet 72 can be soaked before application to the light guide plate 28 with less liquid silicone oil, which was previously mixed with a hardener. As a result, after application of the paper sheet 72 to the light guide plate 28, the silicone oil can cure into an elastic silicone mass, wherein the light transmittance of the silicone material does not suffer as a result.

In a modification, the layer 74 can be made of a resin that is translucent in the cured state, for example, of an epoxy resin or a polyester resin, which should also be indicated by the circles.

For example, a layer 74 of a liquid resin provided with a hardener, is applied to the second main surface 32 of the light ^¬ conductor plate 28. Before the layer 74 of resin cures, the paper sheet 72 is placed, which is then fixed after curing of the resin.

To increase the reflection effect are in the layer 74 of silicone oil or a resin reflector particles 76 in Form of, for example, scandium oxide or zinc sulfide homogeneously distributed. The reflector particles 76 are indicated as points within the circle representing the silicone oil or the resin of the layer 74. The reflector particles 76 increase the reflection effect of the layer 74 or the reflection device 82.

When the layer 74 of the reflective device 82 is made of a resin in which reflector particles 76 are dispersed, the reflection effect against the use of a silicon oil layer 74 is increased and the proportion of the usable light that supports the light guide plate 28 on the first main surface thereof is larger 30 leaves.

The white paper sheet 72 has a basis weight of from 50 g / m ² to 200 g / m ² , preferably from 80 g / m ² to 170 g / m ² , more preferably from 100 g / m ² to 150 g / m ^2, and most preferably from 120 g / m ² .

On the side remote from the silicone oil 74 side of the paper sheet 72, an additional reflective layer 78 is provided, which may be provided for example in the form of a self-adhesive mirror film or a white plastic film.

This sandwich arrangement of the reflective layer 78, the paper sheet 72 and the layer 74 of viscous silicone oil is covered by the housing 68, wherein the bottom 80 rests against the reflective layer 78. The housing 66, the paper sheet 72, the viscous silicone oil 74 and the reflective layer 78 together form a reflection device 82 for the light, which leaves the light guide plate 28 on its second major surface 32.

The illumination device 26 is on the back 16 of the Liquid crystal panel 12 arranged so that the first main surface 30 of the light guide plate 28 is parallel to the rear side 16 of the liquid crystal panel 12 extends. Between the first main surface 30 of the light guide plate 28 and the back 16 of the liquid crystal panel 12, a layer 84 of a thick silicone oil or of an elastic silicone composition is provided. The silicone material is also indicated here by circles. The layer 84 of the elastic silicone composition can be obtained by adding a hardener to a more fluid silicone oil. The layer 84 is in direct contact with the first main surface 30 of the light guide plate 28 and with the surface of the liquid crystal panel 12 on the rear side 16 thereof.

In a modification, the layer 84 may also be made of a resin, for example of an epoxy resin or a polyester resin. In this case, the layer 84 can be obtained by curing a liquid applied resin, to which a hardener has been added, as it is known per se.

By means of the illumination device 26, a uniform high-intensity light is emitted via the first main surface 30 of the light guide plate 28, which is transferred to the liquid crystal panel 12 via the layer 84 of silicone oil or a viscous silicone compound and illuminates it from its rear side 16.

FIGS. 3 and 4 show a further exemplary embodiment in the form of a liquid crystal display panel 10 '.

Components already explained with reference to FIGS. 1 and 2 carry the same reference numbers in FIGS. 3 and 4 and the comments made above apply mutatis mutandis, unless stated otherwise. The supply lines 54 to 64 and the control unit 20 are shown in FIG. - IA -

not shown.

As can be seen in particular in FIG. 4, the liquid-crystal display panel 10 'differs from the liquid-crystal display panel 10 according to FIGS. 1 and 2 in that an RGB chip set 50c with semiconductor light-emitting chips 44, 46 and 48 and the associated supply lines 54 to 64 within a recessed from the second major surface 32 of the light guide plate 28 groove 86 is arranged. Inside the groove 84, the semiconductor light-emitting chips 44, 46 and 48 are likewise surrounded by silicone oil 74. The silicone oil 74, however, no reflector particles 76 are mixed here, so the silicone oil 74 is shown in Figures 3 and 4 as white circles.

In a modification, the RGB chipsets 50a and 50b provided in the liquid crystal display panel 10 shown in FIGS. 1 and 2 at the respective outer edges 34 and 36 of the light guide plate 28 may be provided also in the liquid crystal display panel 10 '. Therefore, the RGB chipsets 50a and 50b are shown in broken lines in FIGS. 3 and 4.

This measure leads, in particular in the case of a large-area liquid-crystal panel 12, to a homogeneous illumination of the rear side 16 of the liquid-crystal panel 12.

FIG. 5 shows a modification of the liquid crystal display panel 10 'shown in FIGS. 3 and 4. In the case of this liquid-crystal display panel 10 ", components already explained with reference to FIGS. 1 to 4 bear the same reference numerals and the comments made above apply mutatis mutandis, unless stated otherwise. The supply lines 54 to 64 and the control unit 20 are not shown in FIG. 5 for the sake of clarity. In the liquid crystal display panel 10 '', the RGB chipset 50c is disposed in a light-transmissive housing 88. The light bar 38c thus formed sits snugly in the groove 86th

The groove 86 is covered on the side of the second main surface 32 of the light guide plate 28 with a translucent cover 90. The cover 90 has, on its side remote from the groove 86, a surface roughness which corresponds to that of the second main surface 32 of the light guide plate 28. The cover 90 is about 1, 0 mm thick.

The housing 88 of the light bar 38c is filled with silicone oil 52. In the silicone oil 74 between the paper sheet 72 and the light guide plate 28, reflector particles 76 in the form of scandium oxide are homogeneously distributed, whereby the reflection of the light leaving the light guide plate 28 on its second major surface 32 is increased, without the scandium oxide 76 the semiconductor luminescent chips 44, 46 and 48 of the

RGB chipset 50c immediately surrounds. The latter could prevent the light emitted from the RGB chip set 50c from being evenly coupled into the light guide plate.

In a modification, the housing 88 of the light bar 38c is dispensed with. Preferably, then, instead of the silicone oil 52, a viscous elastic silicone compound 52 is used. For this purpose, thinner silicone oil is mixed with a hardener, whereby this silicone oil can cure after insertion into the groove 86 to an elastic silicone composition, wherein the light transmission of the silicone material does not suffer.

In a modification of the liquid crystal display panel 10 '' according to FIG. 5, at the respective outer edge 34 and 36, respectively the light guide plate 28 also be provided the light strips 38a and 38b. Therefore, the light bars 38a, 38b are shown with the RGB chipsets 50a and 50b in FIG. 5 in dashed lines.

In the figures 6 and 7, another embodiment in the form of a liquid crystal display panel 10 '' 'is shown. Components already explained with reference to FIGS. 1 to 5 bear the same reference numerals in FIGS. 6 and 7, and the comments made above apply mutatis mutandis, unless stated otherwise. The supply lines 54 to 64 and the control unit 20 are not shown in FIG. 7 for the sake of clarity.

As can be seen in particular in FIG. 7, the housing 40 of each light strip 38a, 38b also comprises here two intermediate walls 92, which subdivide the housing 40 into three inner regions 94, 96 and 98, so that the housing 40 together with the respective outer edge 34 and 36 of the optical waveguide plate 28 limits three mutually insulated interiors. The inner regions 94, 96 and 98 are arranged one behind the other in the direction from the first main surface 30 to the second main surface 32 of the light guide plate 28.

In the interior regions 94 to 98, a plurality of semiconductor luminescent chips 100 are respectively arranged, which emit light of a primary color, for example blue light in a wavelength range from about 420 nm to about 480 nm, when ^exposed to voltage. For the semiconductor light-emitting chips 100, the semiconductor materials already mentioned above are indium gallium nitride (InGaN) and / or gallium nitride (GaN).

The semiconductor light-emitting chips 100 in the inner regions 94, 96 and 98 of the housing 40 are each connected in parallel, but may also be connected in series. In the supervision of FIG. 6, only the semiconductor light-emitting chips 100 can be seen in the inner region 94 of the housing 40. The supply lines 58 to 64 leading to the semiconductor luminescent chips 100 which are not visible in FIG. 6 in the inner regions 96 and 98 of the housing 40 are shown in dashed lines in FIG.

The inner regions 94, 96 and 98 of the housing 40 are filled with silicone oil 52, which is again shown in the form of circles. In the silicone oil 52 in the inner region 94 of the housing 40 phosphor particles 102 are homogeneously distributed, which are made of color center having transparent solid state materials. Such phosphor particles absorb incident light of a primary color and emit light of a secondary color. The phosphor particles 102 are indicated in the form of hexagons. The phosphor particles 102 absorb the light impinging on them and emit red light. For example, the phosphor particles 102 may emit light in a wavelength range of about 630 nm to about 680 nm.

In the silicone oil 52 in the inner region 96 of the housing 40 phosphor particles 104 of another type are homogeneously distributed, which are shown as squares. The phosphor particles 104 absorb the light impinging on them and emit green light. For example, the phosphor particles 104 may emit light in a wavelength range of about 540 nm to about 600 nm.

In the silicone oil 52 in the inner region 98 of the housing 40, other phosphor particles 106 are again homogeneously distributed, which are shown in the form of triangles. The phosphor particles 106 absorb the light impinging on them and emit blue light. For example, the phosphor particles 104 may have light in a wavelength range of about 420 nm emit to about 480 nm.

The phosphor particles 102, 104 and 106 may each be a mixture of several different phosphor particles. By the suitable choice of phosphor particles or phosphor particle mixtures, therefore, the radiation emitted by the light strips 38a, 38b can be converted into a radiation having a spectrum which is adapted to a desired spectrum.

The semiconductor light-emitting chips 100 with the phosphor particles 102, the semiconductor light-emitting chips 100 with the phosphor particles 104 and the semiconductor light-emitting chips 100 with the phosphor particles 106 each form light sources for a first, second or third color.

8 shows another embodiment in the form of a liquid crystal display panel 10 ^{II? l} shown. Components already explained with reference to FIGS. 1 to 7 carry the same reference symbols in FIG. 8 and the comments made above apply mutatis mutandis, unless stated otherwise. The supply lines 54 to 64 and the control unit 20 are not shown in FIG. 8 for the sake of clarity.

The liquid crystal display panel lO ¹ ^{'1 1} of Figure 8 differs from the liquid crystal display panel 10''' according to Figures 6 and 7, among other things, that the light guide plate 28 has three channels 108, 110 and 112th The channels 108, 110 and 112 are parallel to the outer edges 34 and 36 and to the first and second major surfaces 30, 32 of the light guide plate 28. Both in the direction from the outer edge 34 to the outer edge 36 and in the direction of the first main surface 30 to the second major surface 32 of the light guide plate 28, the channels 108, 110 and 112 are offset to _ ^ _

arranged one another, as can be clearly seen in Figure 8.

In the channel 108 is a light bar 114, in the channel 110, a light bar 116 and in the channel 112, a light bar 118 is inserted. Each light bar 114, 116 and 118 comprises a translucent housing 120, which surrounds a plurality of semiconductor light-emitting chips 100 connected in parallel and filled with silicon oil 52, which is shown again in the form of white circles. The housing 120, the semiconductor light-emitting chips 100 and the silicone oil 52 are provided only with the light bar 114 with reference numerals.

In a modification, the housing 120 is dispensed with. Preferably, instead of thinner silicone oil 52, a viscous elastic silicone compound 52 is used.

In the silicone oil 52 in the housing 120 of the light bar 114 are phosphor particles 102, in the silicone oil 52 in the housing 120 of the light bar 116 are phosphor particles 104 and in the SiIi- konöl 52 in the housing 120 of the light bar 118 Phosphor ^¬ particles 106 are each homogeneously distributed. As a result, the light strips 114, 116 and 118 emit light when exposed to voltage, as described above for the phosphor strips 102, 104 and 106 shown in FIGS. 6 and 7.

In a modification of the liquid crystal display panel 10 ^{1 1 1 1} , instead of the channels 108, 110 and 112 in the light guide plate 28 and three recessed from the second major surface 32 of the light guide plate 28 grooves vorgese ^¬ hen, which are formed differently deep. These then each receive one of the light strips 114, 116 and 118 and can be covered with one of the cover 90 corresponding to the light-permeable cover shown in FIG. In a further modification of the liquid crystal display panel 10 ^{1 1 1 1} , the light strips 114, 116 and 118 in a single from the second main surface 32 of the light guide plate 28 recessed groove arranged one behind the other. In this case, each light bar 114, 116 118 must be at least largely transparent to the light emitted by its adjacent light bars 114, 116 and 118, respectively. The latter can also be provided in all other explained embodiments of a liquid crystal display panel.

In the case of the liquid crystal display panel 10 ^{III f} and the modifications explained above, the light strips 38a, 38b according to FIGS. 6 and 7 can also be provided on the respective outer edge 34 or 36 of the light guide plate 28. Therefore, the light bars 38a and 38b are shown by broken lines in FIG.

In the illustrated liquid crystal display panels 10, 10 ', 10'',10''' and 1O ¹ '', the semiconductor light-emitting chips 44, 46 and 48 and 100 are respectively arranged so that they are based on the light guide plate 28 between ' the predetermined by the first main surface 30 level and the predetermined by the second main surface 32 level are arranged.

As mentioned above, the second major surface 32 of the lightguide plate 28 is roughened. This surface roughness is on the order of the wavelength of the light which is reflected by the reflecting means 82. Preferably, the roughness is on the order of 100 microns to 700 microns, preferably from 200 microns to 600 microns, and more preferably from 300 microns to 500 microns.

Due to this surface roughness of the second main surface 32 the light guide plate 28 is achieved an anti-reflection effect, whereby the light reflected by the reflection means 82 again in the direction of the light guide plate 28 light is not partially reflected back through the light guide plate 28 itself and thus can not be used. Thus, the overall yield of the light guide plate 28 is finally increased via the first main surface 30 leaving light increases.

In all embodiments of the liquid crystal display panel 10, 10 ', 10'',10' ¹ ', 1O ^{1 1} ''is the SiIi- konöl 52, which the semiconductor luminescent chips 44, 46 and 48 and 100 in the housings 40th This ensures that the light emitted by the semiconductor light-emitting chips 44, 46 and 48 is reliably coupled into the light guide plate 28. Without the silicone oil 52, there would be a risk that a larger proportion of the light emitted by the semiconductor light-emitting chips 44, 46 and 48 would be reflected by the respective outer edge 34 or 36 of the light guide plate 28 and would not be usable.

The control unit 20 controls the RGB chipsets 50 of the illumination device 26 and the liquid crystal cells 18 of the liquid crystal panel 12 matched to each other. Each on the liquid crystal display panels 10, 10 ', 10'',10''' or 1O ¹ '''picture to be displayed is created for the viewer of a sequence of a red image, a green image and a blue image, which are rapidly generated in succession.

For this purpose, the processor of the control unit 20 calculates, on the basis of an incoming image signal, a corresponding red image, a corresponding green image and a corresponding blue image, the superposition of which gives the desired color image. -? ? _

First, the liquid crystal cells 18 of the liquid crystal panel 12 are driven as necessary for displaying the red image detected by the control unit 20. At the same time, the red light-emitting semiconductor light-emitting chips 44 are supplied with voltage via the supply lines 54 and 56, whereas the semiconductor light-emitting chips 46 and 48 remain inactive for the color green or blue.

Then, the liquid crystal cells 18 of the liquid crystal panel 12 are driven as necessary for displaying the green image detected by the control unit 20. At the same time, the green light-emitting semiconductor luminescent chips 46 are supplied with voltage via the supply lines 58 and 60, whereas the semiconductor luminescent chips 44 and 48 remain inactive for the color red or blue.

As a result, the liquid crystal cells 18 of the liquid crystal panel 12 are driven as necessary for displaying the blue image detected by the control unit 20. At the same time, the blue light-emitting semiconductor light-emitting chips 48 are supplied with voltage via the supply lines 62 and 64, whereas the semiconductor light-emitting chips 44 and 46 remain inactive for the color red or green.

The sequence of three Einfarbbilder (red image, green image and blue image) is performed at least so fast that the menschli ^¬ che eye can no longer dissolve in the individual images in the colors red, green and blue the sequence.

The sequence of the three single-color images takes place here in about 1/25 second, ie each single color image (red image, green image and blue color image). image) is generated within about 3/75 seconds. Therefore, the viewer perceives only a full color image, which results from the superimposition of the three frames in the colors red, green and blue and corresponds to the desired color image to be generated.

When viewing a movie, it usually produces 24 or 25 frames per second. Thus, the liquid crystal display panels 10, 10 ', 10 ", 10" "and 10" "described above are suitable for displaying films.

The above-explained liquid crystal display panels 10, 10 ', 10'',10''' and 10 ¹ ' ¹ ' are simple and in particular inexpensive to produce. Even with large-area liquid crystal display panels 10, 10 ', 10'',10''' and 10 ' ¹ ' ¹ with screen diagonals of 100 inches to 200 inches or more, the color contrast is very good.

The liquid crystal display panels 10, 10 ', 10'',10''' and 10 '''', as explained above, also be made flexible. It is understood that then the other components of the liquid crystal display panels 10, 10 ', 10'', 1O ¹ ''and 10 ¹ ' ¹ ', in particular the housing 40 of the light strips 38 a and 38 b, the housing 68 of the illumination device 26th and the reflection layer 78 and also the light strips 114, 116 and 118 are designed to be correspondingly flexible. Flexible liquid crystal display panels 10, 10 ', 10', 10 '' and 1O ¹ '''can be rolled up for transport to save space. Such thin and flexible screens with a screen diagonal of several meters can be realized.

In addition, the above-explained liquid crystal display panels 10, 10 ', 10'',10''' and 10 ' ^{1 1} ' can be manufactured with low weight. A liquid crystal display panel 10, 10 ', 10'',10' ^• 'and 10' ^II? with a picture diagonal from 50 inches can weigh only about 4 to 5 kg.

The liquid crystal display panels 10, 10 ', 10' ', 10' '' and 10 '' '' are also suitable for small display panels, such as those used in mobile phones or watches. The light strips 38 and 114, 116 and 118 can be manufactured with a thickness of less than 2.5 mm.

Claims

^ ^ Claims

1. Liquid crystal display panel with

a) a liquid crystal panel (12) having a flat viewing side (14) and a plurality of controllable liquid crystal cells (18);

b) an illumination device (26) which is set up such that light emitted by the illumination device (26) illuminates the liquid crystal panel (12) on the side (16) remote from the visible side (14),

characterized in that

c) by the illumination device (26) optionally at least light of a first color, light of a second color and light of a third color can be generated.

2. Liquid crystal display panel according to claim 1, characterized in that the illumination device (26) at least first light-emitting means (44; 100, 102) which emit light of the first color when voltage is applied, second light-emitting means (46; Voltage application emit light of the second color, and third light sources (48, 100, 106), which emit light of the third color when subjected to voltage.

3. A liquid crystal display panel according to claim 2, characterized in that the lighting means (44; 100, 102) for the first color red light in a wavelength range from about 630 nm to about 670 nm, the second color illuminants (46; 100,104) are green light in a wavelength range of about 540 nm to about 600 nm, and the third color light sources (48; 100,106) are blue Emit light in a wavelength range of about 420 nm to 480 nm.

4. Liquid crystal display panel according to claim 2 or 3, characterized in that the first lighting means (44) at least one light of the first color emitting semiconductor light-emitting chip (44), the second light-emitting means (46) at least one light of the second color-emitting semiconductor Luminescent chip (46) and / or the third lighting means (48) at least one. Light of the third color emitting semiconductor light chip (48).

5. Liquid crystal display panel according to one of claims 2 to 4, characterized in that

a) the first lighting means (100, 102) at least one

Semiconductor light-emitting chip (100), which emits light in a primary color and at least partially surrounded by light of the first color-generating phosphor particles (102);

b) the second lighting means (100, 104) comprise at least one semiconductor light-emitting chip (100) which emits light in a primary color and is surrounded at least partially by light of the second color-producing phosphor particles (104);

and or

c) the third lighting means (100, 106) comprise at least one semiconductor light-emitting chip (100), which light in _ ₀ 7 _

a primary color emitted and at least partially surrounded by light of the third color-generating phosphor particles (106).

6. Liquid crystal display panel according to one of claims 1 to 5, characterized in that

a) the illumination device (26) comprises a light guide element (28), which by a first main surface (30) and a second spaced parallel to this second

Main surface (32) is limited and on the side facing away from the visible side (14) (16) of the liquid crystal panel (12) is arranged;

b) the luminous means (44, 46, 48, 100, 102, 100, 104, 100, 106) are arranged in such a way that the luminous means (44, 46, 48, 100, 102, 100, 104, 100, 106) emitted light in the plate-shaped light guide element (28) is coupled.

7. A liquid crystal display panel according to claim 6, characterized in that the lighting means (44; 100, 102) for the first color, the lighting means (46; 100, 104) for the second color and / or the lighting means (48; 106) for the third color relative to the plate-shaped

Light guide element (28) between the plane defined by the first main surface (30) and the plane defined by the second main surface (32) are arranged.

8. The liquid crystal display panel according to claim 7, characterized in that the lighting means (44; 100, 102) for the first color, the lighting means (46; 100, 104) for the second color and / or the lighting means (48; 106) for the third color are arranged laterally next to an outer edge (34, 36) of the plate-shaped light guide element (38).

9. Liquid crystal display panel according to one of claims 6 to 8, characterized in that the lighting means

(44, 100, 102) for the first color, the second color lamps (44, 100, 104) and / or the illuminants

(44; 100, 106) for the third color are arranged in a groove (84) which is provided in one of the main surfaces (30, 32) of the plate-shaped light guide element (28), preferably in its second main surface (32).

10. Liquid crystal display panel according to one of claims 6 to 9, characterized in that the lighting means

(44, 100, 102) for the first color, the second color bulbs (44, 100, 104) and / or the third color bulbs (44; 100, 106) in a channel (108, 110, 112 ), which is provided in the plate-shaped light guide element (28).

11. The liquid crystal display panel according to claim 6, wherein at least one side of each of the first color lamps (44, 100, 102) for the first color, the second color lamps (46, 100, 104), and / or or the luminous means (48; 100, 106) for the third color is at least partially opposite a reflection layer (66), which light emitted by the respective luminous means (44, 46, 48; 100, 102; 100, 104; 100, 106) Direction to the interior of the plate-shaped light guide element (28) reflected.

12. Liquid crystal display panel according to one of claims 6 to 11, characterized in that the luminous means (44; 100, 102) for the first color, the luminous means (44; 100, 104) for the second color and / or the luminous means ( 44; 100, 106) for the third color are surrounded by a light-conducting material (52) which forms the plate-shaped Light conductor element (28) contacted directly.

13. Liquid crystal display panel according to claim 12, characterized in that the light-conducting material (52) is a silicone material, in particular a silicone oil or an elastic silicone compound.

14. Liquid crystal display panel according to one of claims 6 to 13, characterized in that on the side of the second main surface (32) of the plate-shaped light guide element (28), a reflection means (82) is provided, which of the second main surface (32) of the plate-shaped Light guide element (28) reflected light in the direction of the interior of the plate-shaped light guide element (28).

15. Liquid crystal display panel according to claim 14, characterized in that the reflection device (82) comprises a reflection layer (78), in particular a mirror foil or a white foil.

16. Liquid crystal display panel according to claim 14 or 15, characterized in that the reflection means

(82) a layer (74) of silicone material, in particular of viscous silicone oil or of an elastic

Silicone composition, or of a resin, in particular of an epoxy resin or of a polyester resin, which directly contacts the second main surface (32) of the plate-shaped light guide element (28).

17. Liquid crystal display panel according to claim 16, characterized in that in the layer (74) of silicone material or of a resin, a reflector material (76), in particular scandium oxide or zinc sulfide, is largely homogeneously distributed.

18. A liquid crystal display panel according to claim 17, characterized in that the reflection means (82) comprises a white paper sheet (72) formed between the reflective layer (78) and the layer (74)

Silicone material or a resin is arranged.

19. A liquid crystal display panel according to claim 18, characterized in that the paper sheet (72) has a basis weight of from 50 g / m ² to 200 g / m ² , preferably from 80 g / m ² to 170 g / m ² , more preferably from 100 g / m ² to 150 g / m ² and especially preferably 120 g / m ² .

20. Liquid crystal display panel according to one of claims 6 to 19, characterized in that the second

Main surface (32) of the plate-shaped light guide element (28) at least partially a surface roughness in the order of 100 .mu.m to 700 .mu.m, preferably from 200 .mu.m to 600 .mu.m, more preferably from 300 .mu.m to 500 .mu.m and particularly preferably in the order of the wavelength of the light, which is reflected by the reflecting means (82).

21. Liquid crystal display panel according to one of claims 6 to 20, characterized in that the plate-shaped

Light guide element (28) made of glass or acrylic glass or epoxy resin is made.

22. Liquid crystal display panel according to one of claims 4 to 21 with reference to claim 4, characterized in that the first lighting means (44) a plurality of light chips (44) for the first color, the second light means (46) a plurality of light-emitting chips (46) for the second color and / or the third luminous means (48) comprise a plurality of luminous chips for the third color. _

23. Liquid crystal display panel according to one of claims 5 to 22 with reference to claim 5, characterized in that the first lighting means (100, 102) comprises a plurality of light-emitting chips (100) for the primary color, the second light-emitting means (100; 104) a plurality of light-emitting chips (100; 100) for the primary color and / or the third luminous means (100, 106) comprise a plurality of luminous chips for the primary color.