JP3625588B2 - Display panel and panel type display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display panel such as a PDP or LCD having a matrix screen composed of display elements arranged vertically and horizontally, and a display device using the same.
[0002]
2. Description of the Related Art PDP (Plasma Display Panel) has attracted attention as a large-screen display device for high vision. As the screen size increases, the number of display lines increases, and the time required for line-sequential screen scanning for setting display contents increases.
[0003]
[Prior art]
A PDP is a self-luminous display panel in which a discharge space is formed inside by arranging a pair of substrates facing each other with a minute gap and sealing the periphery. A PDP in a matrix display format, in which a screen (screen) is configured by a set of cells as display elements, has V scan electrodes extending in a line direction (for example, the horizontal direction of the screen) and a column direction (for example, a vertical direction of the screen). And H data electrodes extending in the horizontal direction. V is the number of cells in the column direction (number of lines), and H is the number of cells in the line direction. In particular, a surface discharge AC type PDP suitable for color display has V third electrodes that form a sustain electrode pair together with each scan electrode. For example, in a 21-size color display PDP, the number of lines V is 480 and the number of columns H is 1920 (= 640 × 3).
[0004]
In a PDP in a matrix display format, line sequential addressing is performed for display. That is, a drive voltage is sequentially applied to each scan electrode to select V × H cells H by line, and in parallel with this, each data electrode according to the display content of the selected line A drive voltage is selectively applied to. An address discharge is generated between the scan electrode and the data electrode to which the drive voltage is applied. In the AC type, a predetermined charged state is formed by this address discharge, and a main discharge for display is generated by the subsequent application of a sustain voltage having an alternating polarity, so that cells selectively emit light. In the DC type, the address discharge is the main discharge.
[0005]
On the other hand, in the LCD, a technique is widely adopted in which the data electrode is divided at the center in the column direction and the screen is composed of two partial screens having the same number of lines. By dividing the screen, line-sequential screen scanning can be performed for each partial screen, so that the time required for rewriting the display contents can be reduced to ½. Conventionally, in order to make the boundary between the partial screens inconspicuous, there has been proposed an electrode structure in which the division position of the data electrode is selected so as to shift in the column direction between adjacent electrodes (Japanese Patent Laid-Open No. 63-18331). ).
[0006]
[Problems to be solved by the invention]
Also in the PDP, in order to increase the number of display lines, it is necessary to divide the screen in order to avoid a prolonged addressing. As described above, in order to increase the display speed, it is optimal to divide the screen into two equal parts.
[0007]
However, in the current situation, the number of output terminals of the drive circuit components (scan driver IC) having a withstand voltage suitable for the driving of the PDP of the scan electrode is significantly less than the total number of scan electrodes. For this reason, a drive circuit must be configured using a plurality of scanning driver ICs. It is advantageous in terms of cost to unify the model numbers of all scanning driver ICs. The scanning driver IC is configured such that each output terminal is activated in order from the first number to the last number. Therefore, when the entire screen is divided into two, depending on the number of lines, output terminals that cannot be used are output. The number increases, and the utilization factor of the scanning driver IC decreases. For example, a high-definition full screen with 1125 lines is divided into approximately 1 and 2 partial screens with 563 and 562 lines, respectively, and the number of output terminals is 128 (= 2 7). When driving with a scanning driver IC, a total of 10 scanning driver ICs are required, 5 for each partial screen, and the total number of unusable output terminals is 115 [(= 128 × 5-563) + (128 × 5-562)].
In the case of two equal parts, the boundary between the partial screens constituting the screen (entire screen) is the central part most watched by the user in the entire screen, and the screen quality is noticeable and the display quality deteriorates. End up.
[0008]
The present invention is intended to be utilized effectively for driving the dynamic circuit components. Another purpose is to make the screen splitting inconspicuous.
[0009]
[Means for Solving the Problems]
The data electrodes are divided at offset positions shifted from the center in the column direction on the matrix screen (entire screen). As the division position of that, counting the scan electrode from one end of the array direction, substantially corresponds to the number-th scan electrode and the next scan electrodes to an integral multiple of the number of terminal circuit components for driving the scan electrodes Select a position between. When the division positions of adjacent data electrodes are shifted, the maximum value of the shift is set to a number of scan electrode intervals substantially corresponding to an integral multiple of the number of terminals of the circuit component described above.
[0010]
By defining the dividing position by the number of terminals of the circuit component, the number of terminals that cannot be used can be minimized. By separating the division position from the most watched screen center or by shifting the division position of the adjacent data electrode, the influence of the screen division on the display quality is reduced.
[0011]
In this specification, a scan electrode is an electrode that is subject to selective driving in line sequential order. Therefore, for example, in the case of providing control electrodes for stabilizing display at both ends in the column direction of a matrix screen in a PDP, the number of scan electrodes is equal to the number of screen specification lines and the number of scan electrodes provided as control electrodes. Become sum.
[0012]
The panel of the invention of claim 1 includes a scan electrode for selecting each display element of the matrix screen in a row unit, and a data electrode for selecting each display element in a column unit, and each data electrode Is divided into two in the column direction within the display region, so that the display elements can be simultaneously selected in row units in the divided screen, and each data electrode is arranged in the column direction of the display region. a position deviated from the center, and before Symbol said by scan electrodes the number of selected output terminals one set of drive circuit components for selecting the display elements row by row and N, said m as an integer of 1 or more When the scan electrode is counted from one end side of the array, the scan electrode is divided at a position between the (m × N) th scan electrode and the (m × N + 1) th scan electrode.
[0015]
A panel according to a second aspect of the present invention has a third electrode paired with each of the scan electrodes.
According to a third aspect of the present invention, there is provided an apparatus according to the first aspect, comprising: the display panel according to the first aspect; and a drive unit that selectively applies a drive voltage to each display element of the display panel according to display contents The first and second data side driving circuits for applying a driving voltage for selecting each display element to each data electrode in a column unit, and three or more driving circuit components having N selected output terminals And a scan side drive circuit that applies a drive voltage for selecting each display element in a row unit to each scan electrode.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a configuration diagram of a plasma display device 100 according to the present invention.
The plasma display device 100 includes an AC type PDP 1 which is a matrix type color display device, and a drive unit 90 for selectively lighting a large number of cells (display elements) constituting a screen. Used as a receiver.
[0017]
The PDP 1 is a surface discharge type PDP in which a pair of sustain electrodes X and Y are arranged in parallel, and each cell has an electrode matrix having a three-electrode structure in which the sustain electrodes X and Y and the address electrodes A correspond to each other. . The sustain electrodes X and Y extend in the display line direction, and one of the sustain electrodes Y is used as a scan electrode for selecting a cell for each line at the time of addressing. The address electrode A is a data electrode for selecting cells in units of columns and extends in the column direction. However, in the PDP 1, the address electrode A is divided in the display area as described later in order to increase the addressing speed, and includes two partial address electrodes A1 and A2.
[0018]
The drive unit 100 includes a controller 91, a data transfer unit 93, an X driver circuit 94, a Y driver circuit 95, and first and second address driver circuits 96 and 97. Multilevel video data indicating luminance levels of three colors (R, G, B) of each pixel is input to the controller 91 together with various synchronization signals from an external device. Based on the video data, the controller 91 generates binary display data indicating whether or not each cell needs to be turned on and stores it in the image memory 92. At the time of addressing, the data transfer unit 93 reads display data from the image memory 92 one line at a time and transfers it to one address driver circuit 96 (or 97) corresponding to the target line. The address driver circuit 96 (or 97) selectively applies an address pulse to each partial address electrode A1 (or A2) according to the transferred display data. In parallel with this, the Y driver circuit 95 applies a scan pulse to each sustain electrode (scan electrode) Y in accordance with an instruction from the controller. In the sustain period after addressing, the X driver circuit 94 applies a sustain pulse to all the sustain electrodes X, and the Y driver circuit 95 applies a sustain pulse to all the sustain electrodes Y in common. However, the application is alternately performed on the sustain electrode X and the sustain electrode Y.
[0019]
FIG. 2 is a perspective view showing the internal structure of the PDP according to the present invention.
A pair of sustain electrodes X and Y are arranged for each line L on the inner surface of the front glass substrate 11. Each of the sustain electrodes X and Y includes a transparent conductive film 41 and a metal film 42, and is covered with a dielectric layer 17 for AC driving. A protective film 18 made of MgO is deposited on the surface of the dielectric layer 17. On the inner surface of the glass substrate 21 on the back side, a base layer 22, an address electrode A, an insulating layer 24, a partition wall 29, and three color (R, G, B) phosphor layers 28R, 28G, 28B for color display. Is provided. Each partition wall 29 is linear in plan view. The partition walls 29 divide the discharge space 30 into sub-pixels in the line direction, and the gap size of the discharge space 30 is defined to a constant value. One pixel of display consists of three subpixels arranged in the line direction. Since the arrangement pattern of the barrier ribs 29 is a stripe pattern, the portion corresponding to each column in the discharge space 30 is continuous in the column direction across all the lines. The emission colors of the subpixels in each column are the same. A structure within the range of each sub-pixel is a cell C (see FIG. 3).
[0020]
In the PDP 1, the address electrode A and the sustain electrode Y are used for selection (addressing) of lighting (light emission) / non-lighting of the sub-pixel as described above. That is, screen scanning (line selection) is performed by applying a scan pulse to h ( h is the number of lines) sustain electrodes Y, and the sustain electrodes Y and the address electrodes A selected according to the display contents A predetermined charged state is formed for each line L by the counter discharge (address discharge) between the two. After addressing, when a sustain pulse having a predetermined peak value is alternately applied to the sustain electrode X and the sustain electrode Y, a surface discharge (sustain discharge) is generated in a cell in which a predetermined amount of wall charges existed at the end of addressing.
[0021]
Next, the division position of the address electrode A, which is a feature of the present invention, will be described. In the following, it is assumed that the number of lines in the effective display area (the number of lines in the screen specification) is 1125 suitable for high vision, and one control line is provided on each side of the effective display area in the column direction. That is, the number h of lines to be selected and driven is set to 1127. The control line is used for suppressing unnecessary light emission caused by, for example, a partition pattern. In that case, addressing is performed to turn off each cell of the control line.
[0022]
FIG. 3 is a schematic diagram of screen division according to the first embodiment.
When the number of lines m is 1127, the center position in the column direction of the effective display area ES which is a substantial matrix screen is the 564th line when counted from the top line including the control line. In this embodiment, the address electrode is 2 at a position shifted by 76 lines from the center of the screen, that is, at a position between the 640th sustain electrode Y and the next 641st sustain electrode Y (indicated by a circle). It is divided into two partial address electrodes A1, A2.
[0023]
On the other hand, the Y driver circuit 95 has a total of nine scan drivers (integrated circuit components) 951 to 959 having the same model number as scan pulse output means. The number N of output terminals of each of the scan drivers 951 to 959 is 128, and the total number of output terminals in the Y driver circuit 95 is 1152. The scan drivers 951 to 959 are configured to output scan pulses from the output terminals in the order of No. 1 to No. 128 in synchronization with the clock when the chip select signal is active.
[0024]
A total of 1127 sustain electrodes Y are connected to output terminals of predetermined scan drivers 951 to 959 one by one in order from the first corresponding to the first line. In the eight scan drivers 951 to 958, all the output terminals are connected (used) to the sustain electrode Y, and in one scan driver 959, the output terminals from No. 1 to No. 103 are used, and the remaining 25 output terminals are not used. The usage rate of the output terminal is about 98 (= 1127/1152)%.
[0025]
The address electrode division position is such that the number (640) of sustain electrodes Y intersecting one partial address electrode A1 is an integral multiple of the number N of output terminals for one of the scan drivers 951 to 959 (in the example shown in the figure). 5 times). That is, the address electrode A is divided so that the number of output terminals that cannot be used is minimized. If the address electrode A is divided between the 564th sustain electrode Y near the center of the screen and the next sustain electrode Y, it is necessary to assign a total of 10 scan drivers to each of the upper and lower partial screens. The number of output terminals that cannot be used is 153. In this case, the usage rate of the output terminal is 88 (= 1127/1280)%.
[0026]
FIG. 4 is a waveform diagram of an applied voltage showing an example of a driving method.
The display period of one screen (scene) includes a reset period TR, an address period TA, and a sustain period TS.
[0027]
The reset period TR is a period in which the charged state of the dielectric layer 17 is made uniform in order to prevent the influence of the previous lighting state. The address pulse PW is applied to the sustain electrodes X of all lines, and at the same time, the pulse Paw (the same polarity as the address pulse PW) is applied to all the partial address electrodes A1 and A2. In response to the rise of the write pulse PW, a strong surface discharge occurs in all lines, and wall charges are temporarily accumulated in the dielectric layer 17. However, in response to the fall of the write pulse PW, so-called self-discharge occurs due to wall charges, and the wall charges of the dielectric layer 17 disappear. The pulse Paw is applied to suppress the accumulation of wall charges on the wall surface on the back side.
[0028]
The address period TA is a period for performing line sequential addressing. The sustain electrode X is biased to the positive potential Vax with respect to the ground potential. In this state, each line is selected in order from the first line to the 640th line, and each line is selected line by line from the 641st to the 1127th line at the same time as the first and 641st lines. Then, a negative scan pulse Py is applied to the sustain electrode Y of the selected line. That is, the controller 91 sequentially activates each set of the scan driver 951 and the scan driver 956, the scan driver 952 and the scan driver 957, the scan driver 953 and the scan driver 958, the scan driver 954 and the scan driver 959, and then selects simultaneously. The scan driver 955 corresponding to 128 lines from the 513th to the 640th that cannot be made active. Simultaneously with the selection of the line, a positive address pulse Pa having a peak value Va is applied to the partial address electrodes A1, A2 corresponding to the cells to be lit (emitted). In the selected line, in the cell to which the address pulse Pa is applied, an address discharge occurs between the partial address electrodes A1 and A2 and the sustain electrode Y. Since the sustain electrode X is biased to the potential Vax having the same polarity as the address pulse Pa, the address pulse Pa is canceled by the bias, and no discharge occurs between the sustain electrode X and the partial address electrodes A1 and A2.
[0029]
The sustain period TS is a period in which the lighting state set by addressing is maintained in order to ensure luminance. In order to prevent counter discharge, all the partial address electrodes A1 are biased to a positive potential (for example, Vs / 2), and first, a positive sustain pulse Ps having a peak value Vs is applied to all the sustain electrodes Y. Thereafter, a positive sustain pulse Ps having a peak value Vs is alternately applied to the sustain electrode X and the sustain electrode Y. Each time the sustain pulse Ps is applied, a surface discharge is generated in the cell in which wall charges are accumulated in the address period TA.
[0030]
In the present embodiment, the 487 × 2 sustain electrodes Y including the first to 487 (= 1127−640) th sustain electrodes Y and the 641st to 1127th sustain electrodes Y are simultaneously selected. The remaining 153 sustain electrodes Y are excluded from simultaneous selection. The address period TA slightly increases by 1.13 (≈640 / 564) times when 1127 is divided into approximately 264 and 563, but the scan drivers 951 to 959 are used effectively as described above. be able to.
[0031]
FIG. 5 is a schematic diagram of screen division according to the second embodiment. In the figure, components corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals regardless of differences in shape. The same applies to the following drawings.
[0032]
In the example of FIG. 5, the address electrode adjacent to the 512th sustain electrode Y, which is four times the number N of output terminals, and the next 640th sustain electrode Y, which is 640th, which is five times the number N of output terminals. Each address electrode A is divided into two partial address electrodes A1 and A2 so that the division positions of A are irregularly shifted. By irregularly shifting the division positions, the boundaries between the upper and lower partial screens can be made inconspicuous.
[0033]
In the entire effective display area ES, the maximum deviation of the division position of each address electrode A is a distance of 128 lines corresponding to the number N of output terminals for one of the scan drivers 951 to 959. That is, the number of lines that cannot be selected simultaneously with the other lines of the h lines is 128. In the example of FIG. 5, the driving method of FIG. 4 can be applied as in the example of FIG.
[0034]
FIG. 6 is a schematic diagram of screen division according to the third embodiment.
In the example of FIG. 6, one of the adjacent address electrodes A is between the 512th sustain electrode Y, which is four times the number of output terminals N, and the next 513th sustain electrode Y, and the other is the number of output terminals. Between the 640th sustain electrode Y, which is five times N, and the 641st sustain electrode Y, the second partial address electrodes A1 and A2 are divided. That is, each address electrode A is divided alternately at different positions so as to be shifted by 128 lines corresponding to the number N of output terminals.
[0035]
Since the division positions are shifted, the boundaries between the upper and lower partial screens are not noticeable. In addition, since the division positions are regular, it is easy to inspect the formation state of the address electrode A when manufacturing the PDP. In the case of irregularities, it takes time to distinguish between intentional division and disconnection during production. In the example of FIG. 6 as well, the driving method of FIG. 4 can be applied as in the examples of FIGS.
[0036]
FIG. 7 is a schematic diagram of a modified example of the Y driver circuit.
In the first to third embodiments described above, the output terminals of the scan drivers 951 to 959 and the sustain electrodes Y are associated with each other on a one-to-one basis. However, when the drive capability of the scan driver is large The set of sustain electrodes Y that are simultaneously selected can be commonly connected to one output terminal.
[0037]
In FIG. 7, the Y driver circuit 95b has a total of five scan drivers 961 to 965 of the same model number. The number N of output terminals of each of the scan drivers 961 to 965 is 128.
[0038]
The address electrode A is divided at the same position as in the example of FIG. You may divide | segment similarly to the example of FIG. 3 or FIG. The four scan drivers 961 to 964 drive the first to 512th sustain electrodes Y and the 641st to 1127th sustain electrodes Y. A pair of sustain electrodes Y selected at the same time, such as first, 641, second, 642,... 487, and 1127, are connected in common to output terminals of predetermined scan drivers 961 to 964, respectively. The scan driver 965 drives 128 sustain electrodes Y from the 513th to the 640th.
[0039]
The present invention can be applied not only to the surface discharge type PDP 1 but also to a display panel having a number of scan electrodes that requires three or more drive devices, such as a counter discharge type PDP and an LCD. The number h of scan electrodes and the number N of output terminals are not limited to the illustrated numbers. In the case of performing refresh driving for maintaining display contents in a line sequential format, the present invention is also useful when dividing the data electrode in order to increase the refresh time per line and increase the luminance.
[0040]
【The invention's effect】
According to the first to third aspects of the invention, the number of terminals that cannot be connected to the scan electrodes in the drive circuit can be minimized. Further, the screen division can be made inconspicuous.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a plasma display device according to the present invention.
FIG. 2 is a perspective view showing an internal structure of a PDP according to the present invention.
FIG. 3 is a schematic diagram of screen division according to the first embodiment.
FIG. 4 is a waveform diagram of an applied voltage showing an example of a driving method.
FIG. 5 is a schematic diagram of screen division according to the second embodiment.
FIG. 6 is a schematic diagram of screen division according to the third embodiment.
FIG. 7 is a schematic diagram of a modified example of the Y driver circuit.
[Explanation of symbols]
1 PDP (display panel)
90 drive unit 96 address driver circuit (first data side drive circuit)
97 Address driver circuit (second data side driving circuit)
95, 95b Y driver circuit (scan side drive circuit)
100 Plasma display device (panel type display device)
951-959 Scan driver (Drive circuit components)
961-965 Scan driver (drive circuit components)
A Address electrode (data electrode)
A1, A2 Partial address electrode C cell (display element)
ES effective display area (display area)
X Sustain electrode (third electrode paired with scan electrode)
Y scan electrode (sustain electrode)

Claims (3)

A scan electrode for selecting each display element of the matrix screen in a row unit and a data electrode for selecting each display element in a column unit, and each data electrode is arranged in the column direction within the display region. A display panel configured to enable simultaneous selection of display elements in units of lines in a split screen by dividing,
Each of the data electrodes is
The number of selected output terminals for one drive circuit component for selecting each display element in a row unit by the scan electrode is N, where m is a position shifted from the center in the column direction of the display region. It is divided at a position between the (m × N) th scan electrode and the (m × N + 1) th scan electrode when the scan electrode is counted from one end side of the array as an integer of 1 or more. Characteristic display panel. The display panel of claim 1 Symbol placement had a third electrode forming the respective scan electrode and a counter. Is composed of a display panel according to claim 1 Symbol mounting, a drive unit for selectively applying a driving voltage according to the display content to the display elements of the display panel,
The drive unit is
First and second data side driving circuits for applying a driving voltage for selecting each display element in a column unit to each data electrode;
A scan side drive circuit comprising three or more drive circuit components having the same number N of selected output terminals and applying a drive voltage for selecting each display element in a row unit to each scan electrode; A panel type display device characterized by having.

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