JP2000148095A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To let a display device composed of a transmission type display panel and light sources brightly display in color without color mixture. SOLUTION: A time efficiency is improved by extending a lighting period of linear color light sources, and a bright and high chroma display is realized by constituting the light sources of those linear R light sources 60a-60s, linear G light sources 61a-61s, and linear B light sources 62a-62r which are parallel to scanning lines and thinned by using organic EL elements, and selecting scanning lines of an area corresponding to each linear color light sources and lighting them simultaneously when liquid crystal finishes responding, and improves the time efficiency, and realizes a color display with bright and high saturation. Moreover, a higher quality color display without color mixture is achieved by setting a distance between the display panel and the light sources properly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix type display device, and more particularly to a time-division color display type display device.

[0002]

2. Description of the Related Art Conventionally, a color transmission type display device combines a color transmission type display panel having color filters and a white light source, and the display panel has an information signal line (or information electrode) and a scanning signal line (or scanning electrode). The scanning signal lines are sequentially selected by a scanning signal line driving circuit arranged in a two-dimensional matrix and arranged around the panel.
The R, G, and B color image display data is transferred to pixels having color filters of (red), G (green), and B (blue) through the information signal lines. The selection of the scanning signal lines and the driving of the information signal lines are repeated in order from the upper side to the lower side in the display panel as a unit of operation, and a color display is performed by constantly turning on a white light source from the back of the panel. As the white light source, a fluorescent tube, an LED (light emitting diode), or an organic EL (light emitting) element as disclosed in Japanese Patent Application Laid-Open No. 9-50031 is used.

In a color pixel array of such a display device, one scanning signal line and three information signal lines for three colors are required per color pixel, for example, in a vertical stripe pixel array. Further, a color filter with fine processing is also required.

On the other hand, in a monochrome transmission / reception type display device for monochrome display, a display panel does not require a color filter with fine processing corresponding to pixels, and one scanning signal line and one information signal line per monochrome pixel. The number of wirings in a two-dimensional matrix is reduced, and the number of driving circuits for driving them is also small.

[0005]

In a color transmission type display panel, the number of pixels, the number of wirings and the number of driving circuits for driving pixels in the display panel are larger than those of a monochrome transmission type display panel. However, expensive color filters are required for each of the R, G, and B pixels, the panel structure is complicated, and the production yield is affected. Further, the transmittance of each color constituting one pixel is about 20 to 30% on average, and there is a problem that the transmittance of the color filter pixel is 1/3 to 1/4 as compared with the monochrome pixel. Was.

As a method for solving these problems, Japanese Patent Publication No. 63-41078 discloses a black and white transmissive display panel having black and white pixels corresponding to the area of a color pixel.
From the R, G, and B color image display data,
Discloses a method of performing color display by selecting one color image display data, sending it to a black-and-white transmissive display panel, displaying an image, and sequentially controlling lighting of a planar color light source of a color corresponding to the display data in chronological order. Have been.

However, when a planar color light source is used, in order to perform a correct color display, scanning is sequentially performed to complete writing of color information, and lighting is performed only during the time until writing of the next color information is started. Therefore, there is a problem that the effective display time becomes very short and the display becomes dark.

As means for solving this problem, Japanese Patent Application Laid-Open
As disclosed in JP-80716-A, fluorescent tubes and LEs
A light source scanning system has been considered in which D is divided into a plurality of parts in parallel with the scanning electrodes, and these are sequentially scanned in synchronization with the driving of the display panel, and display is possible even during the scanning time.

However, even in this method, the light source in each area cannot be turned on until scanning in each area is completed. Therefore, when a fluorescent tube or LED is used as a color light source, the number of divisions is limited due to the limitation of the shape of the light source. 5 and there is still a problem that the time efficiency is low. In addition, the color light source requires a distance from the display panel due to the nature of the light source, so that it is easy to mix colors with the upper and lower divided areas, and there is a problem in image quality.

The present invention has been made in view of the above problems, and has as its object to irradiate a display panel with high time efficiency.
It is an object of the present invention to provide a display device which is bright, has no color mixture, and can perform color display with high saturation.

[0011]

According to the present invention, there is provided a black-and-white transmissive display panel having a plurality of pixels arranged in a two-dimensional matrix and displaying images by time division driving, and color image display data for each color. First means for selecting and sending each data to the display panel in a time-division manner, and an organic EL element corresponding to the color of the color image display data, and corresponding to a plurality of scanning lines parallel to the scanning lines. And
A plurality of linear color light sources each corresponding to the display panel, and second means for controlling lighting of the linear color light sources according to a display image of the display panel based on the color image display data. A display device having one screen, sequentially transmitting data for one screen to the display panel for each color, sequentially selecting scanning lines for each color, writing pixels for one screen, and corresponding to each linear color light source. This is a display device characterized by being sequentially turned on in synchronization with selection of a scanning line.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a display panel can be a simple black-and-white transmissive display panel by using a light source composed of an organic EL element.
Since the light source can be thinned, the display area can be divided into a large number of areas, the time efficiency can be improved, the lighting period of the light source can be lengthened, and a bright display can be realized. Further, by appropriately setting the distance between the display panel and the light source, it is possible to prevent color mixture of the displayed image. Hereinafter, the present invention will be described in detail.

FIG. 1 is a schematic sectional view of an embodiment of the display device of the present invention. In FIG. 1, 1 is a display panel, 2
Is a diffusion plate, and 3 is a light source. In the present embodiment, the display panel 1 is a liquid crystal element in which liquid crystal is sandwiched between two glass substrates, and is an active matrix display element in which an active element is provided for each pixel. The diffusion plate 2 is made of a film having diffusivity, and is used by giving a thin transparent film of, for example, polycarbonate or the like with appropriate roughness.

The light source 3 is configured by arranging a plurality of R, G, and B linear color light sources in parallel to a scanning line, and each light source is composed of an organic EL element of each color. The surface of the light source 3 is flat. The display panel 1 and the diffusion plate 2 are adhered to each other with an adhesive or the like, and an appropriate space is provided between the diffusion plate 2 and the light source 3. In the present invention, the diffusion plate 2 is not always necessary, but by disposing the diffusion plate 2 between the display panel 1 and the light source 3, the light from the light source 3 can be uniformly irradiated on the display panel 1. Therefore, when a light source having a flat surface is used, it is desirable to use the diffusion plate.

Next, FIG. 2 shows a block diagram of a drive circuit of the display device of the present embodiment. 2, the same members as those in FIG. 1 are denoted by the same reference numerals. 5 is a drive signal generation circuit, 6 is a scan lighting circuit, 7 is a dynamic controller (ASIC), 10 is an information signal line drive circuit, and 11 is a scan signal line drive circuit. In accordance with a control signal from the dynamic controller 7, pixels of each scanning line of the display panel 1 are sequentially scanned by the scanning signal line driving circuit 11, and in synchronization with this, the linear color light sources of the light sources 3 are sequentially lit by the scanning lighting circuit 6. I do. At this time, each image signal is supplied by each information signal line drive circuit 10 so that the image signal is appropriately supplied to the pixels of each scanning line.

Further, a digital RGB image signal (RGB serial) and the like are input to the drive signal generation circuit 5 from a control circuit by a control microcomputer (not shown), and a clock, a control signal and the like are input to the dynamic controller 7. still,
The digital RGB image signal is read out from an image frame memory (not shown) by one for each of R, G, and B.
This is an image signal converted into a field signal.

FIG. 3 schematically shows an example of the configuration of the liquid crystal element used in the present embodiment. This configuration is an example in which a TFT (thin film transistor) is used as an active element and an antiferroelectric liquid crystal (hereinafter, referred to as “AFLC”) is used as a liquid crystal. In the drawing, the same members as those in FIG. 2 are denoted by the same reference numerals. Reference numeral 12 denotes an information signal line (source line), 13 denotes a scanning signal line (gate line), 14 denotes a TFT, and 15 denotes a pixel electrode.

In the configuration shown in FIG. 3, an information signal voltage (source voltage) corresponding to display data is applied from the information signal line drive circuit 10 to the source electrode of the TFT 14 via the information signal line 12, and the scanning signal line drive circuit From 11, a scanning signal voltage (gate voltage) corresponding to the scanning timing is applied to the gate electrode of the TFT 14 via the scanning signal line 13.

The AFLC preferably used in the present construction is
This is an AFLC having no threshold value (hereinafter, referred to as “TAFLC”). As illustrated in FIG. 4, the transmittance continuously changes with a change in applied voltage, and does not have a clear threshold value. Therefore, the transmittance can be continuously changed by controlling the voltage applied to the liquid crystal.

FIG. 5 is a schematic sectional view of a display pixel as an example of the active matrix type liquid crystal element. In FIG. 5, 21 and 31 are glass substrates, 22 is a gate electrode, 2
3 is a gate insulating film, 24 is a semiconductor layer, 25 is an ohmic contact layer, 26 is a source electrode, 27 is a drain electrode, 28 is a channel protective film, 29 is a storage capacitor electrode, 30
And 33 are alignment films, 32 is a common electrode, and 34 is a liquid crystal. In this configuration, for example, the common electrode 32 and the pixel electrode 15 are formed of a transparent conductive material such as ITO, and the semiconductor layer 24 is made of amorphous Si (a-Si) or polycrystalline Si.
(Poly-Si) is used. The on-resistance R _{on of the} TFT 14 is formed, for example, to about 1 kΩ. Further, n ⁺ a-Si or the like is used for the ohmic contact layer 25. Further, the gate insulating film 23 and the channel protective film 28
, Silicon nitride (SiN) or the like is used. Alignment film 3
Polyimide or the like is used for 0 and 33.

FIG. 6 is a partially enlarged view of a light source used in the display device of the present invention. In FIG. 6, 60a, 60b
Is a linear color light source that emits red light (linear R light source);
1a and 61b are linear G light sources emitting green light, 62a and 6
2b is a linear B light source that emits blue light. Each linear color light source is arranged parallel to the scanning line, and its width corresponds to a plurality of scanning lines. Here, assuming that the number of pixels of the liquid crystal element of this embodiment is 90 × 90 and the width of the linear color light source is five scanning lines, the light source of this embodiment has R, G, There are 18 sets of B linear color light sources. However, since extra linear color light sources are required one by one above and below the display panel, the light source is composed of 3 × 18 + 2 = 56 linear color light sources. FIG. 7 shows the positional relationship. As shown in FIG. 7, the light source includes a linear R light source 60a at the upper part of the display panel 1 and a linear G light source 61s at the lower part.
The linear R light sources are 60a to 6
0s, 19 linear G light sources, 61a-61s,
Eighteen linear B light sources 60a to 60r are used. By arranging the linear color light sources in this manner, it is possible to irradiate the entire display panel with each of R, G, and B colors.

The organic EL device constituting the linear color light source is formed by laminating an anode, a hole transport layer, an electron transport layer (light-emitting layer), and a cathode in this order on a substrate such as glass. The substrate surface that is not used faces the display panel side. As an anode material of such an organic EL element, a material having a large work function is desirable, and in addition to ITO, tin oxide,
Gold, platinum, palladium, selenium, iridium, copper iodide, and the like can be used. Also, as a cathode material,
It is desirable that the work function is small, and Mg / Ag (alloy)
In addition, Mg, Al, Li, In, or an alloy thereof can be used. As the electron transport layer, R light source is DCM-doped tris (8-quinolinol) aluminum (hereinafter referred to as “Alq ³ ”) or Nile red-doped Alq ³ , and G light source is Alq ³ or coumarin. Alq ³ and B light sources were N, N'-bis (3-
Methylphenyl) -N, N'-diphenyl- (1,1 '
-Biphenyl) -4,4'-diamine (hereinafter "TP")
) And an Alq ³ layer, and a laminate in which a tetraphenylbutadiene (hereinafter, referred to as “TPB”) layer is provided, bis (8-quinolinolate) phenolate aluminums, and the like can be used.

FIG. 8 is a schematic sectional view showing the positional relationship between the linear color light source and the display panel. FIG. 8 is a cross-sectional view in the direction perpendicular to the scanning lines, and the linear color light source 81 shows one of R, G, and B colors. 2 is a diffusion plate. When the diffusion plate 2 is used, since it is used in close contact with the display panel, it is considered that the distance from the light source to the display panel is substantially equal to the distance to the diffusion plate 2. Here, the distance between the linear color light source 81 and the diffusion plate 2 (that is, the display panel) is d ₁ , and the linear color light source 8 is
The width of 1 (direction perpendicular to the scanning line) is a ₁ , the angle of the light emitted from the linear color light source 81 with respect to the normal direction of the linear color light source 81 is φ, and the angle φ from the end of the linear color light source is φ. the emitted light is the distance in the scanning direction to reach the diffusion plate 2 and a _2.
The distance from the linear color light source 81 refers to the distance from the display panel to the substrate surface where no light emitting layer exists.

At this time, when a ₁ ≦ a ₂ = d ₁ × tan φ is satisfied, even if the linear color light sources 81 of each color divided into three in area are lit in time series, no irradiation is performed. Since there is no portion, the entire surface of the diffusion plate 2 is uniformly irradiated, and the diffused light is uniformly irradiated from the diffusion plate 2 to the display panel. However, since the color mixing and light from the same color of the linear color light sources close to the unlimited increase the a _2, a distance from the ends of the linear color light source 81 to the midpoint of the same color linear color light sources and a ₃ Then, it is preferable that a ₂ ≦ a ₃ . In particular, a ₂
By setting = 2 × a ₁ , only the area illuminated by the light obliquely emitted from the linear color light source 81 is illuminated twice, and the uneven brightness is improved.

The linear color light source used in the present invention preferably has a concave shape in order to enhance the directivity of the emitted light and improve the uniformity. FIG. 11 is a schematic cross-sectional view of a light source having a concave shape in a cross section in a direction perpendicular to a scanning line. Since the organic EL element can be manufactured irrespective of the shape of the substrate, it can be processed into a shape suitable for irradiation of the display panel. With such a concave shape, the directivity of the emitted light is enhanced to reduce color mixing, and the uniformity is enhanced to eliminate the need for a diffusion plate, thereby enabling brighter display without loss due to the diffusion plate. 12 to 14
This is an embodiment of the present invention. As shown in FIGS. 13 and 14, by forming a concave shape on a large number of planes, it is possible to produce a combination of strip-shaped flat substrates, and processing is easy.

In the present invention, the widths of the R, G, and B linear color light sources can be made unequal according to their luminance values. For example, linear R
If the light source has a lower brightness than the other linear color light sources, the width of only the linear R light source is widened and the other linear color light sources are narrowed.

FIG. 9 is a timing chart of the scanning timing of the display panel and the scanning lighting timing of each linear color light source of the light source having the configuration shown in FIG. 7 in the display device of this embodiment.
Shown in In the figure, (a) is a scanning timing chart,
During the screen period (one frame) T _1, for each color indication, R scanning, G scan, three scans of B scan is performed. Each linear color light source is sequentially turned on in synchronization with the scanning of each color. FIG. 9B is a lighting timing chart of the linear color light source, where ON indicates lighting and OFF indicates non-lighting. The lighting timing is after the scanning of the scanning line irradiated by each linear color light source is completed and the response of the liquid crystal of the pixel of the line is completed. The linear R light source 60a and the linear G light source 61s located at the end of the light source irradiate five scan lines, and the linear G light source 61a and the line G located at the second end from the light source end. Since the area to be irradiated with the shape R light source 60s is equivalent to 10 scanning lines, the period for selecting the scanning line of the corresponding area is shorter than that of another linear color light source where the area to be irradiated is equivalent to 15 scanning lines. Therefore, the lighting timing is faster. In FIG. 9B, B
L ₁ is a linear R light source 60a, BL ₂ linear G light source 61a
Of, BL ₃ is linear B light source 62a, a period is completed response of the liquid crystal of the pixels in the selected and corresponding line scan line of the corresponding region.

FIG. 10 shows, in chronological order, the lighting timing of the linear B light source 62a located at the uppermost position of the display panel and the voltage waveform for driving the pixels of the scanning line in the area irradiated by the linear B light source. The illustrated timing chart is shown. Figure 10 (a) scanning signal voltage waveform applied to the scan signal lines G ₁ ~G ₁₅ of the region, (b) the information signal voltage waveform applied to the information signal line S _1, (c) of G ₁ a voltage waveform applied to the liquid crystal of the pixel located at the intersection of S _1, (d) the liquid crystal response of the pixel, a lighting timing of (e) is a linear B light sources.

As shown in FIG. 10, each linear color light source
After passing through appropriate sequentially selects the scanning lines of the scanning region in the selection period _{H 1 (H 1 × 15 =} SC 1), time to liquid crystal response of a pixel of the last scan line finishes (LR _1), It is lit. After a predetermined period of time on, at the same time G ₁ selection for the next R display starts, the linear B light source 62a is turned off. Of the scanning lines (G _{1 to} G ₁₅ for the scanning signal lines) which are the irradiation area of the linear B light source 62 a, the scanning lines irradiated to the linear R light source 60 a in the next R display are the scanning signal lines G _{1 to} G. ₅ , the scanning line selection period is as short as H ₁ × 5, and the linear R light source 6
The lighting period of 0a becomes longer accordingly. Moreover, since the scanning lines emitted to the linear B light source 61a in the next B display of the R display is 10 duty corresponding to the scanning line G ₁ ~G _10, the selection period of the scan line H ₁ × 10 Becomes

As described above, in the display device of the present invention, the scanning line is sequentially selected for each color, and the linear color light source is turned on at the same time when the selection of the scanning line in the corresponding area and the response of the liquid crystal are completed. By turning off the light at the same time as selecting the next color display of the scan line in the corresponding area, during the period when the pixels of each scan line are not illuminated by the linear color light source,
(Selection period of the scanning line of width of the linear color light source × 3 + response period of the liquid crystal) × 3, that is, BL ₃ in FIGS. Therefore, by using a thinned linear color light source, the irradiation period of the light source is greatly improved, and a bright display is possible.

In the above embodiment, TAFLC has been described as an example, but the present invention is not limited to this. In the present invention, a display device having a fast response speed can be formed by using a liquid crystal element using a smectic liquid crystal for a display panel. For example, in addition to the above-mentioned TAFLC, an antiferroelectric material exhibiting three-state stability can be provided. Liquid crystal or DHF (D
reformed Helix Ferroelectric
ic) Nematic liquid crystal such as liquid crystal, surface-stabilized ferroelectric liquid crystal, and VA (Vertical Alignment) liquid crystal having a high response speed can be used.

Further, in the above-described embodiment, an example in which a TFT which is a three-terminal element is used as the active element has been described. However, a two-terminal element such as an MIM can be used. It is also possible to use a simple matrix configuration.

[0033]

EXAMPLE A display device was manufactured using a 90 × 90 pixel active matrix type liquid crystal element using TAFLC as a display panel. The size of one pixel is 560μm × 560μ
m. The TAFLC used was spontaneous polarization Ps at 30 ° C.
Is 150 × 10 ⁻⁹ C / cm ² , the tilt angle θ from the rubbing direction is 30 °, and the dielectric constant ε is 5. The liquid crystal element of this embodiment has a sectional structure shown in FIG. The manufacturing procedure will be described below.

TFT having semiconductor layer made of a-Si
A polyimide precursor polyamic acid ("LP" manufactured by Toray Industries, Inc.) is formed on a substrate on which a pixel electrode made of ITO and ITO is formed.
-64 ") to NMP (N-methylpyrrolidone): nB
1% by weight in a 2: 1 mixed solvent of C (n-butylcellorub)
The coating solution prepared by adding so that
Spin coating was performed for 20 seconds. This board
After drying the solvent in an oven at 80 ° C for 5 minutes,
It was baked for 1 hour in an oven at 200 ° C. for imidization. The obtained polyimide film was about 10 nm thick, and this film was rubbed to form an alignment film. afterwards,
An IPA (isopropyl alcohol) solution in which silica beads having an average particle size of 2.2 μm are dispersed at 0.008% by weight is spin-coated on the surface of the substrate under the conditions of 25 rotations / second and 10 seconds, and the dispersion density is 300 particles / Bead spacers were scattered at about ² mm. On the other substrate, a similar alignment film is formed on the common electrode, and the substrates are bonded together so that the rubbing directions are opposite to each other on the upper and lower substrates.
The cells were cured by heating in an oven at 90 ° C. for 90 minutes. The TAFLC was injected into the obtained cell and sealed. The thickness (cell gap) of the liquid crystal layer was about 2.0 μm.

Next, a procedure for manufacturing a linear color light source will be described.
ITO is used as an anode on a glass substrate by sputtering.
0 mm thick, then TPD as a hole transport layer
And the following electron transport layers were sequentially deposited by vacuum evaporation at 500 °. The degree of vacuum during the deposition was 2.7 × 10
^{−4 to} 4.0 × 10 ⁻⁴ Pa, and the deposition rate is 0.2 to
0.3 nm / s. Finally, as a cathode, Mg and Ag
Are co-deposited at a deposition rate ratio of 10: 1, and Mg / Ag is 10
/ 1 alloy was formed to a thickness of 2000 mm. At this time, the deposition rate was 1 nm / s. The electron transport layer has a linear R
The light source is Alq ³ doped with DCM (4- (dicyanomethylene) -2-methyl-6- (4-dimethylamino-styryl) -4H-pyran), the linear G light source is Alq ³ , and the linear B light source is TPD. A laminate having a TPB layer of about 200 ° between the layer and the Alq ³ layer was used. The respective peak wavelengths were 625 nm, 514 nm, and 460 nm.
Further, by optimizing the applied current and voltage, the linear R light source is 1000 cd / m ² and the linear G light source is 3500 cd / m ² .
m ² and a linear B light source of 500 cd / m ² were obtained.

The width of the linear color light source is 2.8 mm,
The scanning line of the corresponding area is 2.8 mm / 0.56 mm = 5
It is a book. The light source of the present embodiment has the configuration of FIG.
Eighteen sets of G and B linear color light sources, and one extra linear R light source and one extra linear G light source are arranged above and below the display panel.
Further, the surface of the light source was flat, and a diffusion plate having a surface of a polycarbonate film provided with irregularities of an appropriate roughness was disposed on the light source side of the display panel in close contact with an adhesive.

The light sources were arranged on the display panel at intervals of 1 mm. Therefore, in the present embodiment, d ₁ = 1 m
m, a ₁ = 2.8 mm, and φ = 80 °. Therefore, a ₁ ≦ a ₂ = d ₁ × tan φ ≒ 2.84. Since d ₁ × tan φ ≦ a ₃ = 2.5a ₁ , d ₁ ≦ 2.46. In the present embodiment, the color mixture is reduced by setting the distance between the display panel and the light source to 2.46 mm or less. It was found to be prevented. Further, if d ₁ = 2 mm in the present embodiment, a ₂ ≒ 5.67 mm
≒ 2 × a ₁ , and luminance unevenness is further improved.

The display was driven according to the timing charts of FIGS. In this embodiment, one frame T ₁ = 15 ms, and the selection period H ₁ = 5 for each scanning line.
5.6 μs, time required for liquid crystal response completion LR ₁ = 26
μs, BL ₁ = 55.6 × 5 + 26 = 304 μs,
BL ₂ = 55.6 × 10 + 26 = 582 μs, BL ₃ =
55.6 × 15 + 26 = 860 μs. Also, V _g
= 20V, V _SS = 0V, V _C = 8V, V _S1 = 14V, V
_{S2 was set to} 2V. As a result, a brighter and higher-saturation display than ever before was obtained.

[0039]

As described above, according to the present invention, a light source using an organic EL element capable of thinning is combined with a black-and-white transmissive display panel that does not require fine processing such as a color filter. Accordingly, the lighting period of the light source is lengthened, the time efficiency is improved, and a bright and highly saturated color display is realized. By appropriately setting the distance between the display panel and the light source, a higher quality color display without color mixture can be obtained. Also, by making the shape of the light source concave,
The directivity and uniformity of the emitted light are improved, a display with less color mixture is obtained, and a bright display can be performed since a diffuser plate is not required.

Further, by using a smectic liquid crystal element for the display panel, a display panel having a high response speed can be obtained. By using an active element, the selection period can be shortened to increase the speed. , The display time can be increased to provide a bright display.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of one embodiment of a display device of the present invention.

FIG. 2 is a block diagram of a driving circuit of the display device according to the embodiment of the present invention.

FIG. 3 is a schematic plan view illustrating a configuration of a display panel according to an embodiment of the present invention.

FIG. 4 is a diagram showing a voltage-transmittance characteristic of a liquid crystal according to one embodiment of the present invention.

FIG. 5 is a schematic sectional view illustrating a configuration of an example of a display pixel according to an embodiment of the present invention.

FIG. 6 is a partially enlarged view of a light source used in the present invention.

FIG. 7 is a schematic plan view illustrating a positional relationship between a light source and a display panel according to an embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view showing a positional relationship between a linear color light source and a diffusion plate according to an embodiment of the present invention.

FIG. 9 is a lighting timing chart of a linear color light source according to an embodiment of the present invention.

FIG. 10 is a timing chart of a lighting timing of a linear B light source and a drive voltage waveform of a pixel in an area irradiated by the light source according to the embodiment of the present invention.

FIG. 11 is a schematic sectional view of another embodiment of the display device of the present invention.

FIG. 12 is a sectional view of a linear color light source constituting the light source of FIG.

FIG. 13 is a sectional view of another example of the linear color light source used in the present invention.

FIG. 14 is a sectional view of another example of the linear color light source used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display panel 2 Diffusion plate 3 Light source 5 Drive signal generation circuit 6 Scanning lighting circuit 7 Dynamic controller 10 Information signal line drive circuit 11 Scan signal line drive circuit 12 Information signal line 13 Scan signal line 14 TFT 15 Pixel electrode 21, 31 Glass substrate Reference Signs List 22 gate electrode 23 gate insulating film 24 semiconductor layer 25 ohmic contact layer 26 source electrode 27 drain electrode 28 channel protective film 29 storage capacitor electrode 30, 33 alignment film 32 common electrode 34 liquid crystal 60a-60s linear R light source 61a-61s linear G light source 62a-62r Linear B light source 81 Linear color light source

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/20 641 G09G 3/20 641E 5G435 642 642J 3/30 3/30 J H05B 33/14 H05B 33 / 14 A F-term (reference) 2H091 FA44Z FD06 FD22 GA11 LA18 2H093 NA42 NA56 NB10 ND08 ND17 ND24 NE10 NF17 NF20 3K007 AB02 AB04 AB17 BA00 CA01 CB01 DA01 DB03 EB00 FA02 GA02 5C006 AA22 AC02 AF42 AF12 AF12 BC12 BC13 BF02 EA01 FA11 FA21 FA41 FA54 5C080 AA10 BB05 CC03 DD05 DD06 DD22 EE30 FF11 FF12 JJ02 JJ04 JJ06 5G435 AA03 AA16 BB12 BB15 CC12 DD13 EE26 EE30 FF11 GG24 GG26 GG27

Claims (10)

[Claims] 1. A black-and-white transmissive display panel having a plurality of pixels arranged in a two-dimensional matrix and displaying images by time-division driving, and color image display data are sorted by color. A first means for dividing the image data into the display panel, and an organic EL element corresponding to the color of the color image display data, the scanning means being parallel to the scanning lines and corresponding to a plurality of scanning lines; A display device comprising: a linear color light source in which a plurality of each color is arranged; and second means for controlling lighting of the linear color light source in accordance with a display image of the display panel based on the color image display data. The data for the screen is sequentially transmitted to the display panel for each color, the scanning lines are sequentially selected for each color, and the pixels for one screen are written, and each linear color light source is selected in the same manner as the selection of the corresponding scanning line. A display device which is turned on sequentially in anticipation. 2. The width of the linear color light source in the direction perpendicular to the scanning line is a ₁ , the distance between the linear color light source and the display panel is d ₁ , the emission angle of Shako phi, and the distance to the midpoint of the nearest same color linear color light source from an end portion of the linear color light sources and a _3, claims satisfies _{a 1 ≦ d 1 × tanφ ≦} a 3 Item 2. The display device according to Item 1. 3. The display device according to claim 1, wherein the display panel side surface of the color light source has a concave shape in a cross section in a direction perpendicular to a scanning line. 4. The display device according to claim 3, wherein the concave shape is formed by a curved surface. 5. The display device according to claim 3, wherein the concave shape is formed by a plurality of planes. 6. The display device according to claim 1, wherein the display panel is a liquid crystal element having a liquid crystal sandwiched between a pair of substrates. 7. The display device according to claim 6, wherein the liquid crystal is a smectic liquid crystal. 8. The display device according to claim 6, wherein the liquid crystal element is an active matrix type element in which an active element is provided for each pixel and a matrix is formed by scanning signal lines and information signal lines orthogonal to each other. . 9. The display device according to claim 1, further comprising a diffusing optical film between the display panel and the linear color light source. 10. The display device according to claim 9, wherein the optical film is in close contact with a display panel.