JP2006184463A - Image display device and driving method for same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device for outputting an image output from a fluorescence face of a display substrate in a stable state without color unevenness and luminance deviation, and a driving method for the same. <P>SOLUTION: In an image processing circuit 4 for supplying an image signal to a display panel 1 of the image display device, a correction circuit 40 comprises; a characteristic arithmetic circuit 40-3 for correcting the image signal on the basis of an input condition (γvalue); a memory 40-2 in which the value to be corrected by the characteristic arithmetic circuit 40-3 is stored; and a memory 40-1 in which a coefficient for correcting the γvalue stored in the memory is stored, and corrects VI characteristics etc. of each pixel for each of arbitrary display pixels by using a correction object (value) which is different for each color component and the correction coefficient or an arithmetic equation for the correction object (value) and suppresses the luminance deviation of each pixel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display device and a display driving method thereof, and more particularly, in an image display device including a display substrate having a phosphor screen and an electron source substrate that emits electrons toward the phosphor screen of the display substrate. The present invention relates to an image display device capable of outputting an image output from a fluorescent screen of a substrate in a stable state without color unevenness or luminance variation, and a driving method thereof.

  As an image display device that replaces a cathode ray tube (CRT), electron-emitting devices (electron sources) are arranged in a planar and matrix form, and electrons are selectively applied to a planar fluorescent screen (front substrate) facing each other at a predetermined interval. 2. Description of the Related Art Image display devices that display an image by emitting light of an arbitrary color from a phosphor screen by irradiating a line have been developed. This type of image display apparatus is called a field emission display (hereinafter referred to as FED). In addition, among FEDs, a display device using a surface conduction type emitter as an electron source is sometimes classified as a surface conduction type electron emission display (hereinafter referred to as SED). As a generic term, the term FED is used.

  The FED can set the gap between the electron source side substrate and the phosphor screen side substrate to several mm or less, and can be made thinner than a known CRT. The thickness can be equal to or less than that of such an image display device. Therefore, it is expected in terms of weight reduction.

  In addition, since it is a self-luminous type similar to a CRT or plasma display, the brightness of the display image is also easy to obtain.

  On the phosphor screen provided on the inner surface of the front substrate, red (R), blue (B), and green (G) phosphors are arranged in a predetermined size and in a predetermined order. An anode electrode for applying a predetermined sweep voltage to each phosphor is connected to each phosphor on the phosphor screen.

  The substrate on the electron source side has a matrix of scanning lines and signal lines for emitting a predetermined amount of electrons from a previously specified emitter for emitting a phosphor screen facing an emitter at an arbitrary position. It is connected to the.

The above-described FED generally includes a display panel and a drive unit that drives the display panel. The display panel is arranged at a plurality of scanning lines extending in the horizontal (horizontal) direction, a plurality of signal lines extending in the vertical (vertical) direction intersecting with each scanning line, and positions where the respective scanning lines and signal lines intersect. A plurality of display pixels (see, for example, Patent Document 1).
JP 2002-221933 A

  By the way, in recent years, a large FED with a large screen such that the size of the display panel exceeds 40 inches diagonally has been widely demanded by users.

  Reproduction (output) when at least one of the element characteristics of the FED phosphor screen, that is, the display pixel of the display panel, particularly the luminance unevenness of the image displayed by each display pixel or the γ characteristic indicating the correlation of the output signal with the input signal is different There is a problem that the color (color tone) and brightness of the image to be set are uneven.

  In particular, in the case where a white image or a light color of intermediate colors obtained by combining R, G, and B is displayed on the entire screen, there is a problem that the above-described unevenness in color and brightness is conspicuous.

  Although the above-described problem of unevenness in color and brightness is improved by performing γ correction independently on each display pixel, there is a problem that a large memory capacity is required.

  An object of the present invention is to provide an image display device comprising a display substrate having a fluorescent screen and an electron source substrate that emits electrons toward the fluorescent screen of the display substrate. The output is in a stable state with no variation in luminance.

  The present invention holds a first substrate holding an electron beam source, and a phosphor layer that outputs light of a predetermined color when irradiated with an electron beam output from the electron beam source. And a correction target value different for each color component in a display panel driving method comprising: a second substrate opposed to each other at a predetermined interval; and a sidewall having the first substrate and the second substrate as a sealed structure. A driving method of an image display device, wherein a correction coefficient or an arithmetic expression for a target value is used to correct a VI characteristic of each pixel for each arbitrary display pixel and suppress a luminance variation of each pixel. .

  According to another aspect of the present invention, a plurality of scanning lines, a plurality of signal lines intersecting with the plurality of scanning lines, a plurality of scanning lines and a plurality of signal lines are disposed at intersections of the plurality of scanning lines and the plurality of signal lines, respectively. A plurality of display pixels driven corresponding to pixel voltages between the signal lines, a scanning line driver that sequentially drives the plurality of scanning lines, and a period during which each of the plurality of scanning lines is driven by the scanning line driver A signal line driver that drives the plurality of signal lines, a first storage unit that holds a different correction target value for each color component, and a correction coefficient for the correction target value held in the first storage unit or A second storage unit holding an arithmetic expression, and using the correction coefficient or the arithmetic expression stored in the second storage unit, the correction target value held in the first storage unit , For each display pixel, for each pixel Such as to correct the I characteristic, there is provided an image display device characterized by having a suppressing correction circuit luminance variation of each pixel.

  According to another aspect of the present invention, a plurality of scanning lines, a plurality of signal lines intersecting with the plurality of scanning lines, a plurality of scanning lines and a plurality of signal lines are disposed at intersections of the plurality of scanning lines and the plurality of signal lines, respectively. A driving method of an image display device comprising a plurality of display pixels driven corresponding to pixel voltages between signal lines, wherein the plurality of scanning lines are sequentially driven, and each of the plurality of scanning lines is driven. A plurality of signal lines are driven during the period, and the plurality of signal lines are corrected for each arbitrary display pixel by using different correction target values for each color component and correction coefficients or arithmetic expressions for the correction target values. The driving method is characterized in that the driving voltage is supplied to each of the pixels as a pixel voltage.

  According to the present invention, in an image display device comprising a display substrate having a phosphor screen and an electron source substrate that emits electrons toward the phosphor screen of the display substrate, the color (color) of the image output from the phosphor screen of the display substrate An image display device capable of displaying in a stable state with less variation in taste and brightness is obtained.

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

  FIG. 1 shows an example of a circuit configuration of a flat image display device to which the present invention is applied.

  The image display device shown in FIG. 1 is a field emission display (FED) device in which, for example, horizontal 1280 × vertical 768 display pixels are formed. The image display device includes a display panel 1, an X driver (signal line driving circuit) 2, a Y driver (scanning line driving circuit) 3, and a video signal processing circuit 4.

  The display panel 1 includes 768 scanning lines Y (m = 768, Y1 to Ym) provided substantially parallel to the horizontal (horizontal or Y) direction, and a vertical (vertical or X) orthogonal to the scanning lines Y1 to Ym. ) × 1280 signal lines X (n = 1280, X1 to Xn) provided in the direction.

  At the intersections of the scanning lines Y1 to Ym and the signal lines X1 to Xn, m × n (= about 2.76 million) display pixels PX are provided. Each display pixel PX includes three display pixels PX (R, G, B) adjacent in the horizontal direction.

  Each of the individual display pixels PX (R, G, and B) of the display panel 1 is red (R) that emits light by the surface conduction electron-emitting device 11 and the electron beam emitted from the individual electron-emitting device 11. It includes green (G) and blue (B) phosphors 12.

  Each scanning line Y1 to Ym is connected to the electron-emitting device 11 of the display pixel PX in the corresponding horizontal line (row) and used as a scanning electrode. Each signal line X1 to Xn is connected to the electron-emitting device 11 of the display pixel PX in the corresponding column (vertical direction) and used as a signal electrode.

  The signal line driving circuit 2, the scanning line driving circuit 3, and the video signal processing circuit 4 are arranged around the display panel 1 as a display driving unit. For example, a control signal and a control signal are transmitted from a timing controller (not shown) provided outside. The image is displayed on the display panel 1 by supplying the image signal.

  The video signal processing circuit 4 is supplied from an external signal source and processes a video signal including R, G, and B signals in a digital format. The scanning line driving circuit 3 sequentially drives the scanning lines Y1 to Ym using the scanning signal, and the signal line driving circuit 2 displays video while each of the scanning lines Y1 to Ym is driven by the scanning line driving circuit 3. In response to the video signal from the signal processing circuit 4, the signal lines X1 to Xn are driven.

  The video processing circuit 4 includes a correction circuit 40 that corrects VI characteristics and the like of each pixel and suppresses luminance variation of each pixel.

  The X driver (signal line drive circuit) 2 samples and holds a video signal for one horizontal line supplied from the video processing circuit 4 in synchronization with the horizontal synchronization signal HD, and the line memory 20 Drive signal generation unit 21 for generating n drive signals respectively corresponding to video signals for one horizontal line output in parallel from.

  The drive signal generation unit 21 generates n pulse width modulation circuits 22 that generate pulse signals having a pulse width proportional to the gradation level of the video signal of each corresponding pixel, and pulses from the corresponding pulse width modulation circuits 22. It includes n output buffers (AMP) 23 that output the reference voltage Vref from the drive reference voltage terminal to the signal lines X1 to Xn at a predetermined timing for a period equal to the pulse width of the signal.

  The pulse width modulation circuit 22 and the output buffer 23 function as a drive signal output unit for one signal line X. That is, as the pulse signal generated from the pulse width modulation circuit 22, for example, the reference voltage Vref is output and supplied to the n pulse width modulation circuits 22.

  The Y driver (scanning line driving circuit) 3 supplies a scanning signal to each of the corresponding scanning lines Y1 to Ym via m output buffers (AMP) 32 connected to the shift register 31. That is, a scanning signal is supplied to every scanning line Y1, Y2, Y3,..., Ym-1, Ym in order for each line.

  Accordingly, the image signal (luminance signal) Vf is supplied through the arbitrary AMP (buffer) 23 of the X driver 2 in a state where the scanning signal is supplied to the arbitrary scanning line, so that the respective lines intersect. The electron-emitting device (electron source or emitter) 11 of the display pixel PX at the position is selectively turned on, and light of a predetermined color is output from the corresponding pixel PX.

  By the way, in the horizontally long display panel 1 that is demanded by users today, as already described, there are 1280 × 768 display pixels PX (the total number is three times that in R, G, B units). ). For this reason, it is substantially difficult to align the display color and brightness (luminance) for each pixel in each display pixel PX.

  For this reason, it is necessary to correct the video signal to be supplied to the X driver 2 in the correction circuit 40 of the video processing circuit 4.

  As shown in FIG. 2, the correction circuit 40 has a characteristic calculation circuit (calculation unit) 40-3 that corrects a video signal based on an input condition (γ value), for example, and γ to be corrected by the characteristic calculation circuit 40-3. A coefficient for correcting the γ value stored in the memory 2 (second storage unit, that is, the correction target characteristic holding unit) 40-2 in which values (independent of R, G, and B) are stored Is stored in memory 1 (first storage unit, that is, correction coefficient holding unit) 40-1.

  In other words, the correction circuit 40 uses a different γ value (stored in the memory 2) for each color component and a correction coefficient or an arithmetic expression (stored in the memory 1) for the γ value to display an arbitrary display. The characteristics are corrected for each pixel.

  Thereby, the nonuniformity (unevenness) of the color (color tone) and brightness (luminance) for each pixel is corrected at the same ratio. As shown in FIG. 3, for example, the memory constant selection circuit 44S can select a suitable memory constant from among a plurality of correction patterns (constants) prepared as memories 44-1, 44-2,. The memory capacity (number) can be reduced as compared with the method of selecting.

  Note that different characteristics (parameters) can be similarly corrected by preparing a plurality of arithmetic expressions and correction targets (γ values) in accordance with the type and number of correction targets.

  4 and 5 show an example of the structure of the display panel incorporated in the image display device shown in FIG.

  The display panel 1 is opposed to an electron source side substrate (first substrate, hereinafter referred to as a rear panel) 100 having an electron emitting element (electron source or emitter) 11 at a predetermined interval and output from the emitter 11. And a phosphor screen side substrate (second substrate, hereinafter referred to as a face plate) 200 including a phosphor screen (R, G, B phosphor 12) that outputs fluorescence when irradiated with an electron beam.

  As shown in FIG. 5, each of the rear panel 100 and the face plate 200 includes a rectangular back surface (electron source side) glass substrate 101 and a front surface (phosphor screen side) 201 each having a predetermined area. A predetermined number of electron sources (electron-emitting devices) and phosphors (light-emitting devices) are provided in the main portions of the base materials 101 and 201, that is, the display region corresponding portions.

Both substrates 100 and 200 are opposed to each other with a gap (interval) of 1 to 2 mm, and are joined to each other by a side wall 301 provided at the peripheral edge of both substrates 100 and 200. That is, the display panel 1 becomes an envelope 401 having a sealed structure by the two substrates 100 and 200 and the side wall 301. The inside of the envelope 401 is maintained at a degree of vacuum of about 10 ⁻⁴ Pa, for example.

  Between the glass substrates of the rear panel 100 and the face plate 200, a large number of spacers 501 formed in a plate shape or a column shape are provided in order to resist the atmospheric pressure acting on each of them in the assembled state as the envelope 401. Has been placed.

  On one surface of the glass substrate 201 used for the face plate 200, that is, the surface facing inward when assembled as the envelope 401, the phosphors 12 of R, G, and B described above are arranged in a predetermined order. Arranged phosphor screens 211 are provided. The phosphor screen 211 is provided with a metal thin film (metal back layer) that functions as an anode electrode, as will be described in detail later. A sweep voltage of 10 to 15 kV, for example, is applied between the electron source and the anode electrode.

  As shown in FIGS. 4 and 5, the phosphor screen 211 has three types of phosphors 12-that emit R, G, B light when electrons emitted from the individual emitters of the rear panel 100 collide with each other. 1 (R), 12-2 (G), and 12-3 (B), and a light shielding layer (black mask) 221 arranged in a matrix partitioning each phosphor.

  Each phosphor 12-1, 12-2, 12-3 has a longitudinal direction of the face plate 200 (glass substrate 201) in the first direction (X direction) and a width direction orthogonal to the X direction (longitudinal direction). In the case of two directions (Y direction), for example, it is formed in a stripe shape extending in the Y direction. In addition, although each fluorescent substance 12-1 to -3 demonstrated previously, three are arranged as 1 unit.

The light shielding layer 221 is, for example, a mixture of carbon and a binder material, and its resistance value is set to, for example, 10 ³ to 10 ⁸ [Ω]. The content of the binder material is regulated to 80% at maximum.

  As can be easily understood from FIGS. 4 and 5, the light shielding layer (black mask) 221 is arranged in 1280 × 3 columns and 768 rows in the X direction (column direction) and the Y direction (row direction), respectively. Suppose that For example, if the size of one pixel is 0.6 mm square, with respect to the Y direction in which each phosphor layer extends in a band shape, the thickness of the region corresponding to the width (X direction) is the thickness of the horizontal line portion. Compared with narrow. As an example, the width of the vertical line portion is 20 to 100 μm, more preferably 40 to 50 μm, between one pixel composed of R, G and B, that is, between B (12-3) and R (12-1). Then, the remaining portion, that is, between R (12-1) and G (12-2) or between G (12-2) and B (12-3) is 20 to 100 μm, more preferably 20 to 30 μm. On the other hand, the width | variety of a horizontal line part is 150-450 micrometers, More preferably, it is 300 micrometers.

  The phosphor screen 211 is provided on the entire surface covering the phosphor regions 12-1, 12-2, and 12-3 partitioned by the light shielding layer 221, and the phosphor region having an uneven surface is described below. As described above, a thin metal layer, that is, a metal back layer 231 that functions as an anode electrode and is used to reflect light emitted from each phosphor region toward the glass substrate 201 is formed to a predetermined thickness. . Although the term metal back layer is used, this layer is not limited to metal (metal) as long as it can function as an anode, and various materials can be used. . In addition, before the metal back layer 231 is formed, a smoothing layer capable of mutually fixing phosphor particles such as a resin may be provided on the entire surface of the phosphor region.

  As described above, according to the present invention, in the video processing circuit, a variation in color (color) or luminance (brightness) in an arbitrary display pixel uses a correction coefficient and a γ value to be corrected. Correction is performed for each pixel by the calculation by the characteristic calculation unit. Further, by preparing a plurality of arithmetic expressions and correction targets in accordance with the type and number of correction targets, different characteristics (parameters) can be similarly corrected.

  In each of the above-described embodiments, the drive signal may be a voltage amplitude drive system or a pulse width modulation drive system. Moreover, it is applicable also when using both drive systems together.

  The present invention is not limited to the above-described embodiments, and various modifications or changes can be made without departing from the scope of the invention when it is implemented. Moreover, each embodiment may be implemented in combination as appropriate as possible, and in that case, the effect of the combination can be obtained.

Schematic which shows an example of the circuit structure of the image display apparatus with which this invention is applied. Schematic which shows an example of the correction circuit which correct | amends the characteristic of the pixel of the image display apparatus shown in FIG. Schematic which shows an example of the correction circuit which correct | amends the characteristic of the pixel of the image display apparatus shown in FIG. Schematic which shows an example of the structure of the display panel of the image display apparatus shown in FIG. Schematic which shows an example (cross section) of the structure of the display panel of the image display apparatus shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Display panel, 11 ... Surface conduction electron-emitting device, 12 ... Phosphor, 12-1 ... Phosphor (R), 12-2 ... Phosphor (G), 12-3 ... Phosphor (B), 2 ... Signal line driving circuit, 3 ... scanning line driving circuit, 4 ... video signal processing circuit, 40 ... correction circuit, 40-1 ... correction coefficient holding unit, 40-2 ... correction target characteristic holding unit, 40-3 ... calculation unit 44 ... Correction circuit 44-1, 44-2, ..., 44-n ... Memory, 44S ... Memory constant selection circuit, 100 ... Rear panel (electron source side substrate, first substrate), 101 ... Base of first substrate 200: Face plate (phosphor surface side substrate, second substrate), 201: Base material of the second substrate, 211 ... Fluorescent surface, 221 ... Light shielding layer (black mask), 231 ... Metal back layer (metal thin film, Sweep voltage application unit), 241... Getter (impurity adsorption) layer, 301. 01 ... sealing structure (envelope), 501 ... spacer.

Claims (3)

A first substrate holding an electron beam source and a phosphor layer that outputs light of a predetermined color by being irradiated with an electron beam output from the electron beam source are held on the first substrate at predetermined intervals. In a method for driving a display panel, comprising: an opposed second substrate; and a sidewall having the first substrate and the second substrate as a sealed structure.
Using different correction target values for each color component and correction coefficients or arithmetic expressions for the correction target values, correcting the VI characteristics and the like of each pixel for each arbitrary display pixel, thereby suppressing the luminance variation of each pixel A driving method of an image display device characterized by the above. A plurality of scan lines;
A plurality of signal lines intersecting the plurality of scanning lines;
A plurality of display pixels disposed at intersections of the plurality of scanning lines and the plurality of signal lines and driven according to pixel voltages between the pair of scanning lines and the signal lines, respectively;
A scanning line driver for sequentially driving the plurality of scanning lines;
A signal line driver that drives the plurality of signal lines while each of the plurality of scanning lines is driven by the scanning line driver;
A first storage unit that holds a different correction target value for each color component; and a second storage unit that holds a correction coefficient or an arithmetic expression for the correction target value held in the first storage unit. The correction target value held in the first storage unit is used for each arbitrary display pixel by using a correction coefficient or an arithmetic expression stored in the second storage unit. And a correction circuit that suppresses luminance variation of each pixel;
An image display device comprising: A plurality of scan lines;
A plurality of signal lines intersecting the plurality of scanning lines;
A driving method for an image display device, comprising: a plurality of display pixels disposed at intersections of the plurality of scanning lines and the plurality of signal lines, each driven according to a pixel voltage between the pair of scanning lines and the signal lines. Because
The plurality of scanning lines are sequentially driven, and a plurality of signal lines are driven while each of the plurality of scanning lines is driven. The plurality of signal lines have different correction target values for each color component and their corrections. A driving method, wherein a driving voltage corrected for each arbitrary display pixel using a correction coefficient or an arithmetic expression for a target value is supplied to each of the pixels as a pixel voltage.

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