JP2007333887A - Matrix type display driving device, field emission display using the same, and plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a matrix type display driving device which does not degrade brightness even if the number of scanning lines increases, and can scan so many scanning lines that were difficult to be scanned by a conventional method, to provide a field emission display using the matrix type display driving device and to provide a plasma display panel. <P>SOLUTION: Between a data electrode 15a and a substrate 10, a photo-conductive layer 14, a transperent electrode 13, a plurality of kinds of filters 12a to 12c which are stripe-shaped extending in the direction of X and transmit light of wavelengths different from each other, and stripe-shaped waveguides 11a to 11c extending in the direction of Y perpendicular to the direction of X, are arranged, and the data electrode is divided for each sub-pixel at the intersections of the waveguides and the filters, and the light made incident upon the waveguides passes through any one of the two or more kinds of filters and is made incident upon the photo-conductive layer to reduce a resistance value, and the data voltage applied to the transparent electrode is applied to a desired data electrode. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a matrix type display driving apparatus, a field emission display using the same, and a plasma display panel, and in particular, FED (Field Emission Display), PDP (Plasma Display Panel), The present invention relates to a matrix type display driving device for driving a matrix type display such as an LCD (Liquid Crystal Display) or an ELD (Electro Luminescent Display), a field emission display using the matrix type display driving device, and a plasma display panel.

  In a typical matrix display, the scan electrodes and data electrodes are orthogonal. In the FED, for example, scanning is performed using a gate electrode as a scanning electrode and a cathode electrode as a data electrode. In this case, when a scan voltage is applied to the gate electrode and a data voltage is applied to the cathode electrode, electrons are emitted from the cold cathode to emit light. In the FED, display is normally performed by selecting one scan electrode and applying a data voltage to each data electrode when a scan voltage is applied to the scan electrode.

  In the PDP, a time division gradation display method is used. In order to display an image with 256 gradations, at least eight SFs (subfields) are required in one field. Each SF is composed of an initialization period for making the state of the discharge space of all subpixels uniform, a writing period for selecting light emission for each subpixel, and a display period for light emission.

  In the writing period, addressing is performed by the scan / sustain electrode and the data electrode. In other words, the scan voltage is sequentially applied to the scan / sustain electrodes and the data voltage is applied to the data electrodes to perform the write discharge, and light emission or non-light emission is selected in all the subpixels. Thereafter, in the display period, a voltage is applied alternately to all the scan / sustain electrodes and the sustain electrodes to perform display discharge.

Note that Patent Document 1 describes an optical input device that is used in a liquid crystal display device and inputs a scanning signal with light.
JP-A-6-88968

  In the FED, usually, when one scan electrode is selected and a scan voltage is applied to the scan electrode, display is performed by applying a data voltage to each data electrode. Is one horizontal scanning period (1H). For this reason, when the number of scanning lines increases with the increase in the definition of the display, there is a problem that one horizontal scanning cycle is shortened and display luminance is lowered.

  In the PDP, when the number of scanning lines increases as the display becomes higher in definition, the writing period in each SF becomes longer. In order to perform initialization, writing, and display within one field, the display period must be shortened by an amount corresponding to the length of the writing period, and the luminance is lowered.

  In addition, the voltage pulse that causes the write discharge requires a predetermined time. For example, when a voltage pulse width is 1 μsec, a PDP having 4000 scanning lines and 8 SFs is driven, a writing period of 32 msec is required. Since one field is usually 16.7 msec, there is a problem that it is difficult to perform write discharge to all subpixels within one field.

  The present invention has been made in view of the above points, and does not decrease the luminance even when the number of scanning lines increases, and is a matrix type capable of scanning even with the number of scanning lines that is difficult to scan with the conventional method. It is an object of the present invention to provide a display driving device, a field emission display using the display driving device, and a plasma display panel.

The present invention relates to a matrix-type display driving device that performs addressing by means of stripe-shaped scanning electrodes and data electrodes extending in the X direction.
Between the data electrode and the substrate, a photoconductive layer, a transparent electrode, a plurality of types of filters that transmit light of different wavelengths in stripes extending in the X direction, and orthogonal to the X direction and extending in the Y direction. Provide existing striped waveguide,
The data electrode is divided for each subpixel at the intersection of the waveguide and the filter,
Light having a wavelength incident on the waveguide passes through one of the plurality of types of filters and enters the photoconductive layer to reduce a resistance value, and a data voltage applied to the transparent electrode is applied to a desired data electrode. By applying, the luminance does not decrease even when the number of scanning lines increases, and scanning can be performed with the number of scanning lines that is difficult to scan with the conventional method.

  Further, in the matrix type display driving device, the light incident on the waveguide can have multiple wavelengths.

Further, the present invention provides a cold cathode emitter on the data electrode of the matrix type display driving device,
A cold cathode is provided by providing a gate electrode as the scanning electrode having an opening through which the cold cathode emitter is exposed,
By providing the anode electrode and the phosphor on the surface facing the cold cathode, the luminance does not decrease even when the number of scanning lines of the field emission display increases.

Further, the present invention provides a barrier surrounding the data electrode of the matrix type display driving device, and provides a phosphor at a location surrounded by the barrier,
By providing the scan / sustain electrodes and sustain electrodes as the scan electrodes on the surface facing the data electrodes, scanning is possible even if the number of scan lines in the plasma display panel increases.

  According to the present invention, the luminance does not decrease even when the number of scanning lines is increased, and scanning is possible even with the number of scanning lines that is difficult to scan with the conventional method.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Structure of data voltage application unit>
FIG. 1 shows a structural diagram of an embodiment of a data voltage application section of a matrix type display which is an apparatus of the present invention. In the figure, a plurality of stripe-shaped waveguides 11a, 11b, and 11c extending in the Y direction are provided on a flat rear substrate 10. The waveguides 11a, 11b, and 11c are made of, for example, quartz or silicon. A plurality of stripe-shaped filters 12a, 12b, and 12c that are orthogonal to the waveguide and extend in the X direction are provided on the waveguides 11a, 11b, and 11c. The filters 12a, 12b, and 12c are, for example, dichroic filters.

A transparent electrode 13 such as ITO (indium oxide doped with tin: In ₂ O ₃ : Sn) and a photoconductive layer 14 such as amorphous silicon or amorphous selenium are laminated on the filters 12a, 12b, and 12c. The photoconductive layer 14 has a characteristic that the resistance value at the light incident position decreases. Note that a PIN photodiode or an avalanche photodiode may be used instead of the photoconductive layer.

A plurality of data electrodes 15a, 15b, 15c, etc. are provided on the photoconductive layer 14 so as to be independent at each subpixel at the intersection of the waveguide and the filter. The data electrodes 15a, 15b, 15c are made of chromium, for example. Thereby, the matrix type display drive device 20 is configured.
2A and 2B show a side view and a plan view of a configuration in which light is incident on a waveguide. In the figure, light having a wavelength Aw emitted from a light source 41 is distributed by an optical distributor 44 and is incident on three optical shutters 47a, 47b, and 47c. Similarly, light of wavelengths Bw and Cw emitted from the light sources 42 and 43 is also distributed by the light distributors 45 and 46, and is incident on each of three optical shutters (only 48c and 49c are shown).

  Each optical shutter opens and closes independently, and light of wavelengths Aw, Bw, and Cw passing through the opened shutter among the optical shutters 47c, 48c, and 49c is coupled by the optical coupler 53c and is incident on the waveguide 11c. Similarly, light of wavelengths Aw, Bw, and Cw that has passed through the opened shutter among three optical shutters (47a and 47b are shown) is coupled by optical couplers 53a and 53b, respectively, and is incident on waveguides 11a and 11b. .

  A method of applying the data voltage will be described below with reference to FIG. The pulse width or intensity of light incident on each of the waveguides 11a, 11b, and 11c is image data. The scanning line is orthogonal to the waveguides 11a, 11b, and 11c. Here, consider simultaneously scanning three scanning lines. Light of three wavelengths (wavelengths Aw, Bw, and Cw) is incident on each of the waveguides 11a, 11b, and 11c.

  Further, the sequentially arranged filter 12a transmits only the wavelength Aw, the filter 12b transmits only the wavelength Bw, and the filter 12c transmits only the wavelength Cw, and does not transmit other wavelengths used. A data voltage is applied to the transparent electrode 13. On the other hand, no voltage is applied to all the data electrodes 15.

  When light of wavelength Aw is incident on the waveguide 11b shown in the center of FIG. 1, the light of wavelength Aw is transmitted through the filter 12a, so that the resistance value of the photoconductive layer immediately below the data electrode 15a decreases. At this time, the data electrode 15a and the transparent electrode become conductive, and the voltage value of the data electrode 15a becomes the voltage value applied to the transparent electrode 13. However, since the light having the wavelength Aw does not pass through the filters 12b and 12c, the resistance value of the photoconductive layer immediately below the data electrodes 15b and 15c does not decrease. Therefore, the voltage value of the data electrodes 15 b and 15 c does not become the voltage value applied to the transparent electrode 13.

  Similarly, when light of wavelength Bw or Cw is incident on the waveguide 11b, the voltage value of the data electrode 15b or 15c becomes the voltage value applied to the transparent electrode 13. Therefore, it is possible to independently control whether or not to apply a voltage to the data electrodes 15a, 15b, and 15c by controlling light of three wavelengths incident on the waveguide 11b.

<Embodiment of FED using apparatus of the present invention>
FIG. 3 is an exploded perspective view of an embodiment of an FED using the apparatus of the present invention, and FIG. 4 is a sectional view of a cold cathode of the FED. In this embodiment, the gate electrode is a scan electrode and the cathode electrode is a data electrode.

  3 and 4, the insulating layer 21 provided with the opening 23 on the data electrodes 15a, 15b, 15c and the like formed on the photoconductive layer 14 of the matrix type display driving device 20 and the X direction. A plurality of existing gate electrodes 22a, 22b, and 22c are stacked. The insulating layer 21 is made of, for example, silicon dioxide, and the gate electrodes 22a, 22b, and 22c as scanning electrodes are made of chrome.

  On the data electrodes 15a, 15b, 15c, etc. in the opening 23, a cold cathode emitter 24 is provided so as to be exposed from the opening 23. The cold cathode emitter is formed of carbon nanotubes, silicon, molybdenum or the like.

  An anode electrode 26 and a phosphor 27 are formed on the flat front substrate 25. A vacuum is applied between the front substrate 25 and the rear substrate 10.

FIG. 5 is a plan view of an embodiment of the FED, and FIG. 6 shows an embodiment of a driving waveform of the FED. FIG. 5 shows gate electrodes n to n + 5, waveguides m and m + 1, and the like. Here, the light incident on each of the waveguides m and m + 1 has three wavelengths (wavelengths Aw, Bw, and Cw), and simultaneously scans three consecutive rows of gate electrodes n to n + 2. A cathode voltage _VK is applied to the transparent electrode 13.

At time _{t 0} in FIG. 6, a gate voltage is applied to _{V G} to the gate electrode n to n + 2. Further, the voltage _VL is applied to the light sources of the wavelengths Aw and Cw of the waveguide m and the light source of the wavelength Bw of the waveguide m + 1, and the respective lights are incident on the respective waveguides. If the light incident method shown in FIG. 2 is used, the light source always emits light, and on / off of light incidence in each waveguide is controlled using the optical shutters 47a to 49c.

As a result, the voltage V _K is applied to the cathode electrodes A _em and C _em corresponding to the data electrodes 15a and 15c on the waveguide m and the cathode electrode B _{em + 1} corresponding to the data electrode 15b on the waveguide m + 1.

In the subpixels (m, n), (m, n + 2), and (m + 1, n + 1), the voltage applied to the cold cathode emitter 24 is V _G −V _K > V _E (V _E : emission start voltage). Electrons are emitted from the cold cathode emitter 24. In the subpixels (m, n + 1), (m + 1, n), and (m + 1, n + 2), the voltage applied to the cold cathode emitter 24 is V _G (<V _E ), so that no electrons are emitted from the cold cathode emitter 24. . At this time, since the gate voltage _{V G} to the gate electrodes n + 3 to n + 5 is not applied, no electron emission in the sub-pixel of the gate electrode n + 3~n + 5.

Next, at time _{t 1,} applying a gate voltage _{V G} from the gate electrode n + 3 to n + 5. Further, the voltage _VL is applied to the light sources of the wavelengths Aw and Bw of the waveguide m and the light source of the wavelength Cw of the waveguide m + 1, and each light is incident on each waveguide. As a result, the voltage V _K is applied to the cathode electrodes A _em and B _em corresponding to the data electrodes 15a and 15b on the waveguide m and the cathode electrode C _{em + 1} corresponding to the data electrode 15c on the waveguide m + 1.

Subpixel (m, n + 3), (m, n + 4), the (m + 1, n + 5 ), the voltage applied to the cold cathode emitter 24 is _V G _-V K> _{V E,} the electrons from the cold cathode emitter 24 Released. No electrons are emitted from the subpixels of the subpixels (m, n + 5), (m + 1, n + 3), (m + 1, n + 4), and the gate electrodes n to n + 2. By repeating this, the FED can be scanned.

Here, as shown in FIG. 7, gradation display can be performed by using a pulse width modulation method that adjusts the pulse width of the voltage _VL applied to the light sources having wavelengths Aw, Bw, and Cw incident on the waveguide. .

  In the above-described embodiment, three rows of gate electrodes are simultaneously scanned using light incident on the waveguide as three wavelengths. For this reason, it is possible to triple the period during which electrons are emitted. Since the length of the light emission period is proportional to the luminance, the luminance is tripled by this driving method. In addition, by setting the wavelength of light incident on the waveguide to an i (i is an integer of 2 or more) wavelength, it is possible to simultaneously scan the i rows of gate electrodes and further increase the luminance.

  Although FIG. 4 shows a cold cathode in which an opening 23 is provided in the insulating layer 21 and the gate electrode 22a and a cold cathode emitter 24 is formed on the gate electrode 22a in the opening 23, a focus for focusing an electron beam is shown. The present invention can also be applied to other cold cathodes such as cold cathodes provided with electrodes, MIM cold cathodes, and SCE cold cathodes.

<Embodiment of PDP using apparatus of the present invention>
FIG. 8 shows an exploded perspective view of an embodiment of a PDP using the apparatus of the present invention.

  In FIG. 8, a barrier 30 extending in the Y direction is provided on the photoconductive layer 14 of the matrix display driving device 20, and a phosphor 31 is applied to a portion surrounded by the barrier 30.

  Striped scanning / sustaining electrodes 36a, 36b, 36c and sustaining electrodes 37a, 37b, 37c, which are orthogonal to the waveguides 11a, 11b, 11c and extend in the X direction, are alternately formed on the planar front substrate 35. An insulating layer 38 and an MgO layer 39 are formed.

  Scan / sustain electrodes 36a, 36b, and 36c and sustain electrodes 37a, 37b, and 37c as scan electrodes are a bus electrode such as gold and a transparent electrode such as ITO. A mixed gas such as Ne—Xe is sealed between the front substrate 35 and the rear substrate 10.

FIG. 9 is a plan view of an embodiment of a PDP, and FIGS. 10 and 11 show an embodiment of a driving waveform of the PDP. FIG. 9 shows scan / sustain electrodes n to n + 5, sustain electrodes n to n + 5, waveguides m, m + 1, and the like. Here, the light incident on each of the waveguides m and m + 1 has three wavelengths (wavelengths Aw, Bw, and Cw), and the scanning / sustaining electrodes n to n + 2 in three consecutive rows are scanned simultaneously. A data voltage V _D is applied to the transparent electrode 13.

  FIG. 10 shows a case where one field is divided into eight SFs (subfields) in time division gradation display. Each SF is composed of an initialization period for making the state of the discharge space of all subpixels uniform, a writing period for selecting light emission for each subpixel, and a display period for emitting light. Although the period is the same, the display period is doubled in order from 1SF to 8SF. FIG. 11 shows voltage pulse waveforms in the writing period and the display period in one SF.

Applying a scanning voltage _{V SCAN} to scan and sustain electrodes n to n + 2 at time _{t 1} in FIG. 11. Further, the voltage _VL is applied to the light sources of the wavelengths Aw and Bw of the waveguide m and the light source of the wavelength Cw of the waveguide m + 1, and each light is incident on each waveguide. As a result, the voltage V _D is applied to the data electrodes A _em and B _em corresponding to the data electrodes 15 a and 15 b on the waveguide m and the data electrode C _{em + 1} corresponding to the data electrode 15 c on the waveguide m + 1.

In the subpixels (m, n), (m, n + 1), and (m + 1, n + 2), the potential difference between the data electrode and the scan / sustain electrode is −V _SCAN + V _D > V _B (V _B : discharge start voltage). Therefore, an address discharge occurs in the discharge space. Charges generated by the discharge are accumulated as wall charges. No discharge occurs in the subpixels (m, n + 2), (m + 1, n), and (m + 1, n + 1). At this time, since the scan voltage _{V SCAN} to scan and sustain electrodes n + 3 to n + 5 is not applied, address discharge in the sub-pixel of the scan and sustain electrodes n + 3 to n + 5 does not occur.

Then, at time _{t 2, the} application of a scan voltage _{V SCAN} from the scan and sustain electrodes n + 3 to n + 5. Further, the voltage _VL is applied to the light sources of the wavelengths Aw and Cw of the waveguide m and the light source of the wavelength Bw of the waveguide m + 1, and the respective lights are incident on the respective waveguides. As a result, the voltage V _D is applied to the data electrodes A _em and C _em corresponding to the data electrodes 15a and 15c on the waveguide m and the data electrode B _{em + 1} corresponding to the data electrode 15b on the waveguide m + 1. In the subpixels (m, n + 3), (m, n + 5), and (m + 1, n + 4), the potential difference between the data electrode and the scan / sustain electrode is −V _SCAN + V _D > V _B. Happens. Charges generated by the discharge are accumulated as wall charges.

No discharge occurs in subpixels (m, n + 4), (m + 1, n + 3), and (m + 1, n + 5). Further, since the scan and sustain electrodes n to n + 2 to the scan voltage _{V SCAN} is not applied, address discharge does not occur in the scan and sustain electrodes n to n + 2 of the sub-pixels. By performing this for all the scan / sustain electrodes, light emission or non-light emission of each sub-pixel is selected.

Display discharge is performed from time t4 to t5. Applying a discharge sustain voltage V _SUS alternately to all the sustain electrodes and the scan and sustain electrodes. In the subpixel in which the wall charges are accumulated, discharge occurs and light is emitted. By performing this for 8SF, gradation display can be performed. Here, the description is made using 8SF, but the same number of SFs can be used for driving.

  In the above embodiment, the FED and the PDP have been described as examples. However, the present invention may be applied to an LCD or an ELD.

  In the present invention, since it is possible to scan a plurality of lines simultaneously by performing addressing using light of a plurality of wavelengths in a matrix display, scanning can be easily performed even in a display having a large number of scanning lines, In addition, the luminance is improved. Therefore, this is particularly effective for an ultra-high-definition display or a three-dimensional display having a large number of scanning lines.

It is a structure figure of one Embodiment of the data voltage application part of the matrix type display which is this invention apparatus. It is the side view and top view of a structure which inject light into a waveguide. It is a disassembled perspective view of one Embodiment of FED using the apparatus of this invention. It is sectional drawing of the cold cathode of FED. It is a top view of one embodiment of FED. It is a figure which shows one Embodiment of the drive waveform of FED. It is a figure for demonstrating the gradation display of FED. It is a disassembled perspective view of one Embodiment of PDP using the apparatus of this invention. It is a top view of one Embodiment of PDP. It is a figure for demonstrating the gradation display of PDP. It is a figure which shows one Embodiment of the drive waveform of PDP.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Back substrate 11a, 11b, 11c Waveguide 12a, 12b, 12c Filter 13 Transparent electrode 14 Photoconductive layer 15a, 15b, 15c Data electrode 20 Matrix type display drive device 41, 42, 43 Light source 44, 45, 46 Light distributor 47a, 47b, 47c, 48a, 49a Optical shutter 53a, 53b, 53c Optical coupler 21 Insulating layer 22a, 22b, 22c Gate electrode 23 Opening 24 Cold cathode emitter 25, 35 Front substrate 26 Anode electrode 27, 31 Phosphor 30 Barrier 36a, 36b, 36c Scan / sustain electrode 37a, 37b, 37c Sustain electrode 38 Insulating layer 39 MgO layer

Claims (4)

In a matrix type display driving device that performs addressing by a scanning electrode and a data electrode in a stripe shape extending in the X direction,
Between the data electrode and the substrate, a photoconductive layer, a transparent electrode, a plurality of types of filters that transmit light of different wavelengths in stripes extending in the X direction, and orthogonal to the X direction and extending in the Y direction. Provide existing striped waveguide,
The data electrode is divided for each subpixel at the intersection of the waveguide and the filter,
Light having a wavelength incident on the waveguide passes through one of the plurality of types of filters and enters the photoconductive layer to reduce a resistance value, and a data voltage applied to the transparent electrode is applied to a desired data electrode. A matrix-type display driving device characterized by applying voltage. The matrix type display driving device according to claim 1, wherein
A matrix type display driving device characterized in that light incident on the waveguide has multiple wavelengths. A cold cathode emitter is provided on the data electrode of the matrix type display driving device according to claim 1 or 2,
A cold cathode is provided by providing a gate electrode as the scanning electrode having an opening through which the cold cathode emitter is exposed,
A field emission display comprising an anode electrode and a phosphor provided on a surface facing the cold cathode. A barrier surrounding the data electrode of the matrix type display driving device according to claim 1 or 2 is provided, and a phosphor is provided at a location surrounded by the barrier,
A plasma display panel, wherein a scan / sustain electrode and a sustain electrode as the scan electrode are provided on a surface facing the data electrode.

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