WO2012114735A1 - プラズマディスプレイ装置 - Google Patents
プラズマディスプレイ装置 Download PDFInfo
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- WO2012114735A1 WO2012114735A1 PCT/JP2012/001191 JP2012001191W WO2012114735A1 WO 2012114735 A1 WO2012114735 A1 WO 2012114735A1 JP 2012001191 W JP2012001191 W JP 2012001191W WO 2012114735 A1 WO2012114735 A1 WO 2012114735A1
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/28—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/28—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels
- G09G3/288—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels
- G09G3/291—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels controlling the gas discharge to control a cell condition, e.g. by means of specific pulse shapes
- G09G3/292—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels controlling the gas discharge to control a cell condition, e.g. by means of specific pulse shapes for reset discharge, priming discharge or erase discharge occurring in a phase other than addressing
- G09G3/2927—Details of initialising
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/30—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/28—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels
- G09G3/288—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels
- G09G3/291—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels controlling the gas discharge to control a cell condition, e.g. by means of specific pulse shapes
- G09G3/294—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels controlling the gas discharge to control a cell condition, e.g. by means of specific pulse shapes for lighting or sustain discharge
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/28—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels
- G09G3/288—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels
- G09G3/296—Driving circuits for producing the waveforms applied to the driving electrodes
- G09G3/2965—Driving circuits for producing the waveforms applied to the driving electrodes using inductors for energy recovery
Definitions
- the present invention relates to a plasma display device using an AC surface discharge type plasma display panel.
- a typical AC surface discharge type panel as a plasma display panel (hereinafter abbreviated as “panel”) has a large number of discharge cells formed between a front substrate and a rear substrate that are arranged to face each other.
- a plurality of pairs of display electrodes composed of a pair of scan electrodes and sustain electrodes are formed in parallel with each other on the front glass substrate.
- a dielectric layer and a protective layer are formed so as to cover the display electrode pairs.
- the back substrate has a plurality of parallel data electrodes formed on the glass substrate on the back side, a dielectric layer is formed so as to cover the data electrodes, and a plurality of barrier ribs are formed thereon in parallel with the data electrodes. ing. And the fluorescent substance layer is formed in the surface of a dielectric material layer, and the side surface of a partition.
- the front substrate and the rear substrate are arranged opposite to each other and sealed so that the display electrode pair and the data electrode are three-dimensionally crossed.
- a discharge gas containing xenon at a partial pressure ratio of 5% is sealed, and a discharge cell is formed in a portion where the display electrode pair and the data electrode face each other.
- ultraviolet rays are generated by gas discharge in each discharge cell, and the phosphors of each color of red (R), green (G) and blue (B) are excited and emitted by the ultraviolet rays. Display an image.
- a subfield method is generally used as a method for displaying an image in an image display area of a panel by combining binary control of light emission and non-light emission in a discharge cell.
- each discharge cell In the subfield method, one field is divided into a plurality of subfields having different emission luminances.
- each discharge cell light emission / non-light emission of each subfield is controlled by a combination according to a desired gradation value.
- each discharge cell emits light with the emission luminance of one field set to a desired gradation value, and an image composed of various combinations of gradation values is displayed in the image display area of the panel.
- each subfield has an initialization period, an address period, and a sustain period.
- an initialization waveform is applied to each scan electrode, and an initialization operation is performed to generate an initialization discharge in each discharge cell.
- wall charges necessary for the subsequent address operation are formed, and priming particles (excited particles for generating the discharge) for generating the address discharge stably are generated.
- the scan pulse is sequentially applied to the scan electrodes, and the address pulse is selectively applied to the data electrodes based on the image signal to be displayed.
- an address discharge is generated between the scan electrode and the data electrode of the discharge cell to emit light, and a wall charge is formed in the discharge cell (hereinafter, these operations are also collectively referred to as “address”). ).
- the number of sustain pulses based on the luminance weight determined for each subfield is alternately applied to the display electrode pairs composed of the scan electrodes and the sustain electrodes.
- a sustain discharge is generated in the discharge cell that has generated the address discharge, and the phosphor layer of the discharge cell emits light (hereinafter referred to as “lighting” that the discharge cell emits light by the sustain discharge, and “non-emitting”). Also written as “lit”.)
- each discharge cell is made to emit light with the luminance according to the luminance weight.
- each discharge cell of the panel is caused to emit light with a luminance corresponding to the gradation value of the image signal, and an image is displayed in the image display area of the panel.
- a weak initializing discharge is generated during the initializing period.
- an erase discharge is generated after the last sustain pulse is generated in the sustain period. Therefore, it is necessary to generate a ramp waveform voltage that gradually rises or falls and applies it to one or both of the display electrode pairs.
- a Miller integration circuit is mainly used (see, for example, Patent Document 1).
- the voltage applied to each electrode tends to be relatively high. Therefore, the maximum voltage tends to be higher in the above-described rising ramp waveform voltage, and the minimum voltage tends to be lower in the falling ramp waveform voltage.
- a scan electrode driving circuit having a simple configuration is desired. It is rare.
- the present invention includes a panel including a plurality of discharge cells having scan electrodes, and a scan electrode driving circuit that applies a drive voltage waveform to the scan electrodes, and includes a plurality of subfields having an initialization period, an address period, and a sustain period. It is a plasma display device that uses one field to display an image on a panel.
- the scan electrode driving circuit includes a down waveform generation circuit that generates a down ramp waveform voltage applied to the scan electrode during the initialization period, and a scan pulse generation that generates a scan pulse applied to the scan electrode during the address period. Circuit.
- the scan pulse generation circuit includes a first power source that generates a positive voltage superimposed on a reference potential of the scan pulse generation circuit, and a plurality of high voltage side transistors that output a high voltage side voltage of the first power source to each of the plurality of scan electrodes. And a plurality of low voltage side transistors for outputting a voltage on the low voltage side of the first power supply to each of the plurality of scan electrodes.
- the downstream waveform generating circuit includes a second power source that generates a positive voltage superimposed on a reference potential, a Miller integrating circuit in which one terminal is connected to the high voltage side of the second power source and the other terminal is connected to the ground potential. And generating a falling ramp waveform voltage that drops to a negative voltage.
- the number of components constituting the scan electrode drive circuit can be suppressed, and a scan electrode drive circuit having a simple configuration can be realized.
- the scan electrode driving circuit includes a resistance dividing circuit and a comparison circuit.
- the resistance dividing circuit resistively divides the output voltage of the power supply having the higher output voltage of the first power supply and the second power supply to generate a voltage equal to the voltage of the power supply having the lower output voltage. Then, the output terminal of the power supply having the lower output voltage is connected to the node where the voltage equal to the voltage of the power supply having the lower output voltage is generated through a diode for preventing backflow.
- the comparison circuit the voltage at the above-mentioned node or the voltage obtained by dividing the voltage at the above-mentioned node by resistance is compared with a predetermined threshold voltage to detect an overvoltage of the first power supply or the second power supply.
- FIG. 1 is an exploded perspective view showing a structure of a panel used in a plasma display device according to an embodiment of the present invention.
- FIG. 2 is an electrode array diagram of a panel used in the plasma display device according to one embodiment of the present invention.
- FIG. 3 is a diagram schematically showing an example of a circuit block constituting the plasma display device in one embodiment of the present invention.
- FIG. 4 is a diagram schematically showing a configuration example of a scan electrode driving circuit of the plasma display device in one embodiment of the present invention.
- FIG. 5 is a diagram schematically showing an example of a drive voltage waveform applied to each electrode of the panel used in the plasma display device according to one embodiment of the present invention.
- FIG. 6 is a diagram schematically showing a configuration example of an overvoltage detection circuit in the scan electrode driving circuit of the plasma display device in accordance with the exemplary embodiment of the present invention.
- FIG. 1 is an exploded perspective view showing the structure of panel 10 used in the plasma display device according to one embodiment of the present invention.
- a plurality of display electrode pairs 14 each including a scanning electrode 12 and a sustaining electrode 13 are formed on a glass front substrate 11.
- a dielectric layer 15 is formed so as to cover the scan electrode 12 and the sustain electrode 13, and a protective layer 16 is formed on the dielectric layer 15.
- This protective layer 16 has been used as a panel material in order to lower the discharge start voltage in the discharge cell, and has a large secondary electron emission coefficient and durability when neon (Ne) and xenon (Xe) gas is sealed. It is made of a material mainly composed of magnesium oxide (MgO).
- the protective layer 16 may be composed of a single layer or may be composed of a plurality of layers. Moreover, the structure which particle
- a plurality of data electrodes 22 are formed on the rear substrate 21, a dielectric layer 23 is formed so as to cover the data electrodes 22, and a grid-like partition wall 24 is further formed thereon.
- a phosphor layer 25R that emits red (R)
- a phosphor layer 25G that emits green (G)
- a phosphor layer 25B that emits blue (B).
- the phosphor layer 25R, the phosphor layer 25G, and the phosphor layer 25B are collectively referred to as a phosphor layer 25.
- the front substrate 11 and the rear substrate 21 are arranged to face each other so that the display electrode pair 14 and the data electrode 22 intersect each other with a minute space therebetween, and a discharge space is provided in the gap between the front substrate 11 and the rear substrate 21.
- the outer peripheral part is sealed with sealing materials, such as glass frit.
- sealing materials such as glass frit.
- a mixed gas of neon and xenon is sealed in the discharge space as a discharge gas.
- the discharge space is partitioned into a plurality of sections by the barrier ribs 24, and discharge cells constituting pixels are formed at the intersections between the display electrode pairs 14 and the data electrodes 22.
- one pixel is composed of three consecutive discharge cells arranged in the direction in which the display electrode pair 14 extends.
- the three discharge cells are a discharge cell having a phosphor layer 25R and emitting red (R) (red discharge cell), and a discharge cell having a phosphor layer 25G and emitting green (G) (green). And a discharge cell having a phosphor layer 25B and emitting blue (B) light (blue discharge cell).
- the structure of the panel 10 is not limited to the above-described structure, and may be, for example, provided with a stripe-shaped partition wall.
- FIG. 2 is an electrode array diagram of panel 10 used in the plasma display device according to one embodiment of the present invention.
- the panel 10 includes n scan electrodes SC1 to SCn (scan electrode 12 in FIG. 1) extended in the horizontal direction (row direction and line direction) and n sustain electrodes SU1 to SUn (FIG. 1).
- the sustain electrodes 13) are arranged, and m data electrodes D1 to Dm (data electrodes 22 in FIG. 1) extending in the vertical direction (column direction) are arranged.
- m discharge cells are formed on one pair of display electrodes 14 and m / 3 pixels are formed.
- FIG. 3 is a diagram schematically showing an example of a circuit block constituting the plasma display device 30 in one embodiment of the present invention.
- the plasma display device 30 includes a panel 10 and a drive circuit that drives the panel 10.
- the drive circuit includes an image signal processing circuit 31, a data electrode drive circuit 32, a scan electrode drive circuit 33, a sustain electrode drive circuit 34, a timing generation circuit 35, and a power supply circuit (not shown) that supplies necessary power to each circuit block. It has.
- the image signals input to the image signal processing circuit 31 are a red image signal, a green image signal, and a blue image signal. Based on the red image signal, the green image signal, and the blue image signal, the image signal processing circuit 31 sets each gradation value of red, green, and blue (a gradation value expressed by one field) to each discharge cell. To do.
- the input image signal includes a luminance signal (Y signal) and a saturation signal (C signal, or RY signal and BY signal, or u signal and v signal, etc.).
- a red image signal, a green image signal, and a blue image signal are calculated based on the luminance signal and the saturation signal, and then, each gradation value of red, green, and blue is set in each discharge cell. Then, the red, green, and blue gradation values set in each discharge cell are associated with image data indicating lighting / non-lighting for each subfield (light emission / non-light emission corresponds to digital signals “1” and “0”). Data) and output. That is, the image signal processing circuit 31 converts the red image signal, the green image signal, and the blue image signal into red image data, green image data, and blue image data and outputs the converted image data.
- the timing generation circuit 35 generates various timing signals for controlling the operation of each circuit block based on the horizontal synchronization signal and the vertical synchronization signal.
- the generated timing signal is supplied to each circuit block (data electrode drive circuit 32, scan electrode drive circuit 33, sustain electrode drive circuit 34, image signal processing circuit 31, etc.).
- Scan electrode driving circuit 33 includes an upward waveform generation circuit, a downward waveform generation circuit, a sustain pulse generation circuit, and a scan pulse generation circuit (not shown in FIG. 3), and is based on a timing signal supplied from timing generation circuit 35.
- a drive voltage waveform is created and applied to each of scan electrode SC1 through scan electrode SCn.
- the up waveform generation circuit and the down waveform generation circuit generate an initialization waveform to be applied to scan electrode SC1 through scan electrode SCn during the initialization period based on the timing signal.
- the sustain pulse generating circuit generates a sustain pulse to be applied to scan electrode SC1 through scan electrode SCn during the sustain period based on the timing signal.
- the scan pulse generating circuit includes a plurality of scan electrode driving ICs (scan ICs), and generates scan pulses to be applied to scan electrode SC1 through scan electrode SCn during the address period based on a timing signal.
- Sustain electrode drive circuit 34 includes a sustain pulse generation circuit and a circuit (not shown in FIG. 3) for generating voltage Ve, and generates and maintains a drive voltage waveform based on the timing signal supplied from timing generation circuit 35.
- the voltage is applied to each of electrode SU1 through sustain electrode SUn.
- a sustain pulse is generated based on the timing signal and applied to sustain electrode SU1 through sustain electrode SUn.
- voltage Ve is generated based on the timing signal and applied to sustain electrode SU1 through sustain electrode SUn.
- the data electrode drive circuit 32 generates address pulses corresponding to the data electrodes D1 to Dm based on the image data of each color output from the image signal processing circuit 31 and the timing signal supplied from the timing generation circuit 35. . Then, the data electrode drive circuit 32 applies the address pulse to the data electrodes D1 to Dm during the address period.
- FIG. 4 is a diagram schematically showing a configuration example of the scan electrode drive circuit 33 of the plasma display device 30 in one embodiment of the present invention.
- the scan electrode drive circuit 33 includes an overvoltage detection circuit including a resistance dividing circuit and a comparison circuit as will be described later, but the overvoltage detection circuit is omitted in FIG.
- Scan electrode drive circuit 33 includes scan pulse generation circuit 40, sustain pulse generation circuit 50, upstream waveform generation circuit 55, downstream waveform generation circuit 60, and transistor Q59.
- Transistor Q59 is a separation switch. For example, the transistor Q59 is shut off when the down waveform generation circuit 60 is operating. In this way, the upstream waveform generation circuit 55, the sustain pulse generation circuit 50, and the downstream waveform generation circuit 60 are electrically separated to prevent current backflow.
- the scan pulse generation circuit 40 includes a first power supply E41, a high voltage side transistor QH1 to a high voltage side transistor QHn, and a low voltage side transistor QL1 to a low voltage side transistor QLn.
- the high voltage side transistor QH1 to the high voltage side transistor QHn are referred to as “transistor QH1 to transistor QHn”
- the low voltage side transistor QL1 to low voltage side transistor QLn are referred to as “transistor QL1 to transistor QLn”.
- node A the potential at the node indicated by “A” in FIG. 4 is the reference potential of the scan pulse generation circuit 40.
- this node is referred to as “node A”.
- the first power supply E41 superimposes the positive voltage Vp on the voltage at the node A which is the reference potential of the scan pulse generation circuit 40.
- the first power supply E41 is configured using a transformer and a rectifier circuit.
- the first power supply E41 may be a power supply circuit having another configuration.
- the transistors QH1 to QHn are connected to the high voltage side terminal of the first power supply E41, and the high voltage side voltage of the first power supply E41 (that is, the voltage obtained by superimposing the positive voltage Vp on the voltage of the node A). Are applied to scan electrode SC1 through scan electrode SCn.
- the transistors QL1 to QLn are connected to the low voltage side terminal of the first power supply E41, and the low voltage side voltage (that is, the voltage at the node A) of the first power supply E41 is applied to the scan electrode SC1 to the scan electrode SCn. Apply.
- the scan pulse generation circuit 40 Based on the timing signal supplied from the timing generation circuit 35, the scan pulse generation circuit 40 switches on / off the transistors QH1 to QHn and the transistors QL1 to QLn in the write period to generate a scan pulse, and scan Applied to electrode SC1 through scan electrode SCn.
- Sustain pulse generation circuit 50 includes transistor Q51, transistor Q52, and power recovery unit 53.
- the power recovery unit 53 has an inductor and a capacitor for power recovery. Then, the power stored in the interelectrode capacitance of the panel 10 is recovered in the power recovery capacitor by LC resonance between the inductor and the interelectrode capacitance of the panel 10. Further, the electric power stored in the power recovery capacitor is reused for the generation of the sustain pulse by the LC resonance.
- the transistor Q51 clamps the voltage at the node A to the voltage Vs on the high voltage side of the sustain pulse.
- the transistor Q52 clamps the voltage at the node A to the voltage 0 (V) on the low voltage side of the sustain pulse.
- Sustain pulse generation circuit 50 operates while switching transistor Q51, transistor Q52, and power recovery unit 53 during the sustain period based on the timing signal supplied from timing generation circuit 35.
- the sustain pulse is generated by displacing the potential at the node A between the voltage Vs and the voltage 0 (V).
- each transistor for example, an insulated gate bipolar transistor (IGBT), a field effect transistor (Field Effect Transistor: FET), or the like can be used.
- IGBT insulated gate bipolar transistor
- FET Field Effect Transistor
- an insulated gate bipolar transistor is used for each of the transistor Q51, the transistor Q52, and the transistor Q59.
- a diode for bypassing current from the emitter to the collector (current in the direction opposite to the forward current flowing during normal operation) is connected in parallel to each transistor. This is to protect the insulated gate bipolar transistor from reverse current.
- this diode can be omitted. This is because the diode (body diode) built in the field effect transistor can bypass the current in the reverse direction from the emitter to the collector.
- the upstream waveform generating circuit 55 is a Miller integrating circuit composed of a transistor Q55, a capacitor C55, and a resistor R55.
- This Miller integrating circuit is connected to the power source of the voltage Vr, and the upward waveform generating circuit 55 gradually increases the voltage at the node A toward the voltage Vr.
- this Miller integrating circuit generates an upward ramp waveform voltage that gradually rises toward the voltage Vr.
- the downstream waveform generation circuit 60 includes a second power supply E61, a Miller integration circuit, and a transistor Q63.
- the second power supply E61 superimposes the positive voltage Va on the voltage at the node A, which is the reference potential of the scan pulse generation circuit 40.
- the second power supply E61 is configured using a transformer and a rectifier circuit.
- the second power supply E61 may be a power supply circuit having another configuration.
- the Miller integrating circuit includes a transistor Q62, a capacitor C62, and a resistor R62.
- one terminal is connected to the high-voltage side terminal of the second power supply E61, and the other terminal is connected to the ground potential (voltage 0 (V)).
- the terminal on the high voltage side of the second power supply E61 is referred to as “node B”.
- the Miller integration circuit gently decreases the voltage at the node A toward the negative voltage ( ⁇ Va) by gradually decreasing the voltage at the node B toward the voltage 0 (V). Thus, this Miller integrating circuit generates a downward ramp waveform voltage that gently falls toward the negative voltage ( ⁇ Va).
- the transistor Q63 clamps the node B of the second power supply E61 to the ground potential (voltage 0 (V)). As a result, the voltage at the node A is clamped to a negative voltage ( ⁇ Va).
- the transistor Q63 is turned on and the voltage at the node A is clamped to a negative voltage ( ⁇ Va), so that a negative voltage ( ⁇ Va) is applied to the transistors QL1 to QLn.
- a voltage Vc obtained by superimposing the voltage Vp on the negative voltage ( ⁇ Va) can be applied to the transistor QHn.
- the switching element QLh is turned off and the switching element QHh is turned on, whereby the switching element QHh is turned on.
- the voltage Vc can be applied to the scan electrode SCh via.
- the scan electrode drive circuit 33 sets the voltage at the node A, which is the reference potential of the scan pulse generation circuit 40, to the positive voltage Vs, the voltage 0 (V), or the negative voltage ( ⁇ Va). Can do. Further, the rising ramp waveform voltage is generated by raising the voltage at the node A toward the voltage Vr, and the falling ramp waveform voltage is generated by dropping the voltage at the node A toward the negative voltage ( ⁇ Va). be able to.
- the plasma display device in the present embodiment drives the panel 10 by the subfield method.
- the subfield method one field of an image signal is divided into a plurality of subfields on the time axis, and a luminance weight is set for each subfield. Therefore, each field has a plurality of subfields having different luminance weights.
- Each subfield has an initialization period Ti, an address period Tw, and a sustain period Ts. Based on the image signal, light emission / non-light emission of each discharge cell is controlled for each subfield. That is, a plurality of gradations based on the image signal are displayed on the panel 10 by combining the light-emitting subfield and the non-light-emitting subfield based on the image signal.
- an initialization operation is performed in which an initialization discharge is generated in the discharge cell and wall charges necessary for the address discharge in the subsequent address period Tw are formed on each electrode.
- Initialization operation includes “forced initialization operation” that forcibly generates an initializing discharge in all discharge cells regardless of the operation of the immediately preceding subfield and an addressing discharge that occurs in the addressing period of the immediately preceding subfield.
- the forced initializing operation the rising ramp waveform voltage and the falling ramp waveform voltage are applied to scan electrode SC1 through scan electrode SCn to generate an initializing discharge in the discharge cells.
- a ramp waveform voltage that falls is applied to scan electrode SC1 through scan electrode SCn, and an initializing discharge is selectively generated in the discharge cells.
- the forced initializing operation is performed in all discharge cells in the initializing period of one subfield, and in the initializing period of the other subfield.
- a configuration for performing the selective initialization operation in all the discharge cells will be described.
- the present invention is not limited to this configuration.
- the configuration may be such that the forced initialization operation is performed only once for a plurality of fields.
- the structure which provides the subfield which has only one initialization period in several subfields, or the structure which provides the subfield which has only one initialization period in several fields may be sufficient.
- the initialization period Ti in which the forced initialization operation is performed is referred to as “forced initialization period”, and the subfield having the forced initialization period is referred to as “forced initialization subfield”.
- the initialization period Ti in which the selective initialization operation is performed is referred to as “selective initialization period”, and the subfield having the selective initialization period is referred to as “selective initialization subfield”.
- subfield SF1 is a forced initialization subfield
- the other subfields are selected initialization subfields.
- the present invention is not limited to the above-described subfields as subfields for forced initialization subfields and subfields for selective initialization subfields.
- the structure which switches a subfield structure based on an image signal etc. may be sufficient.
- a scan pulse is applied to scan electrode SC1 through scan electrode SCn and an address pulse is selectively applied to data electrode D1 through data electrode Dm to generate an address discharge selectively in the discharge cells to emit light. . Then, an address operation is performed to form wall charges in the discharge cells for generating the sustain discharge in the subsequent sustain period Ts.
- sustain pulses of the number obtained by multiplying the luminance weight set in each subfield by a predetermined proportional constant are alternately applied to scan electrode SC1 through scan electrode SCn and sustain electrode SU1 through sustain electrode SUn.
- a sustain operation is generated in the discharge cell that has generated an address discharge during the address period, and a sustain operation for emitting light from the discharge cell is performed.
- This proportionality constant is a luminance multiple.
- the luminance weight represents a ratio of the luminance magnitudes displayed in each subfield, and the number of sustain pulses corresponding to the luminance weight is generated in the sustain period in each subfield. Therefore, for example, the subfield with the luminance weight “8” emits light with a luminance about eight times that of the subfield with the luminance weight “1”, and emits light with about four times the luminance of the subfield with the luminance weight “2”. Therefore, for example, if the subfield with the luminance weight “8” and the subfield with the luminance weight “2” are emitted, the discharge cell can emit light with the luminance corresponding to the gradation value “10”.
- each discharge cell emits light with various gradation values by selectively emitting light in each subfield by controlling light emission / non-light emission of each discharge cell for each subfield in a combination according to the image signal. That is, a gradation value corresponding to an image signal can be displayed on each discharge cell, and an image based on the image signal can be displayed on the panel 10.
- one field is composed of eight subfields from subfield SF1 to subfield SF8, and (1, 2, 4, 8) is assigned to each subfield from subfield SF1 to subfield SF8. , 16, 32, 64, 128) will be described. Then, the subfield SF1 is set as a forced initialization subfield, and the subfields SF2 to SF8 are set as selective initialization subfields.
- the number of subfields constituting one field, the frequency of occurrence of forced initialization operation, the luminance weight of each subfield, and the like are not limited to the above-described numerical values.
- the structure which switches a subfield structure based on an image signal etc. may be sufficient.
- FIG. 5 is a diagram schematically showing an example of a drive voltage waveform applied to each electrode of the panel 10 used in the plasma display device 30 in one embodiment of the present invention.
- FIG. 5 shows scan electrode SC1 that performs the address operation first in the address period, scan electrode SCn that performs the address operation last in the address period (for example, scan electrode SC1080), data electrode D1 to data electrode Dm, and sustain electrode SU1 to The drive voltage waveform applied to each of the sustain electrodes SUn is shown.
- Scan electrode SCi, sustain electrode SUi, and data electrode Dk in the following represent electrodes selected based on image data (data indicating light emission / non-light emission for each subfield) from among the electrodes.
- FIG. 5 shows a subfield SF1 that is a forced initialization subfield, a subfield SF2 and a subfield SF3 that are selective initialization subfields.
- the waveform shapes of the drive voltages applied to scan electrode SC1 through scan electrode SCn in the initialization period are different.
- each subfield except subfield SF1 is a selective initialization subfield, and substantially the same drive voltage waveform in each period except the number of sustain pulses. Is generated.
- the voltage 0 (V) is applied to the data electrodes D1 to Dm, and the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn. ) Is applied.
- a voltage Vp is applied to scan electrode SC1 through scan electrode SCn after voltage 0 (V) is applied, and an upward ramp waveform voltage that gradually rises from voltage Vp to (voltage Vp + voltage Vr) is applied.
- voltage Vp is set to a voltage lower than the discharge start voltage with respect to sustain electrode SU1 through sustain electrode SUn, and (voltage Vp + voltage Vr) is a discharge start voltage with respect to sustain electrode SU1 through sustain electrode SUn. Set the voltage to exceed.
- scan electrode drive circuit 33 when an upward ramp waveform voltage is applied to scan electrode SC1 through scan electrode SCn will be described.
- the transistor Q52 and the transistor Q59 are turned on, and the voltage at the node A is clamped to the voltage 0 (V). Then, the transistors QH1 to QHn are turned on, the transistors QL1 to QLn are turned off, and a voltage obtained by superimposing the voltage Vp on the voltage of the node A is applied to the scan electrodes SC1 to SCn. Thus, voltage Vp is applied to scan electrode SC1 through scan electrode SCn.
- the transistor Q52 is turned off. Then, a current is supplied to the transistor Q55 through the resistor R55, and the Miller integrating circuit of the upward waveform generating circuit 55 is operated. As a result, the voltage at the node A gradually increases from the voltage 0 (V) toward the voltage Vr. A voltage obtained by superimposing voltage Vp on voltage at node A is applied to scan electrode SC1 through scan electrode SCn via transistor QH1 through transistor QHn. Therefore, an upward ramp waveform voltage that gradually increases from voltage Vp toward (voltage Vp + voltage Vr) can be applied to scan electrode SC1 through scan electrode SCn.
- the wall voltage on the electrode represents a voltage generated by wall charges accumulated on the dielectric layer covering the electrode, the protective layer, the phosphor layer, and the like.
- a positive voltage Ve lower than the voltage Vs is applied to the sustain electrodes SU1 to SUn.
- the voltage 0 (V) is kept applied to the data electrodes D1 to Dm.
- a downward ramp waveform voltage that gently decreases from voltage Vs to negative voltage Vi is applied to scan electrode SC1 through scan electrode SCn.
- Voltage Vs is set to a voltage lower than the discharge start voltage for sustain electrode SU1 to sustain electrode SUn
- voltage Vi is set to a voltage exceeding the discharge start voltage for sustain electrode SU1 to sustain electrode SUn.
- scan electrode drive circuit 33 when a downward ramp waveform voltage is applied to scan electrode SC1 through scan electrode SCn will be described.
- the transistor Q55 is turned off to stop the operation of the Miller integrating circuit of the upstream waveform generating circuit 55.
- the transistors Q51 and Q59 are turned on to clamp the voltage at the node A to the voltage Vs.
- the transistors QH1 to QHn are turned off, the transistors QL1 to QLn are turned on, and the voltage Vs that is the voltage at the node A is applied to the scan electrodes SC1 to SCn.
- the transistor Q51 and the transistor Q59 are turned off. Then, a current is supplied to the transistor Q62 through the resistor R62, and the Miller integrating circuit of the downward waveform generating circuit 60 is operated. As a result, the voltage at the node B gradually decreases from (voltage Vs + voltage Va) toward the voltage 0 (V), and the voltage at the node A gradually decreases from voltage Vs toward the negative voltage ( ⁇ Va). .
- a voltage at node A is applied to scan electrode SC1 through scan electrode SCn via transistor QL1 through transistor QLn. Therefore, it is possible to apply a downward ramp waveform voltage that gently drops from voltage Vs toward negative voltage ( ⁇ Va) to scan electrode SC1 through scan electrode SCn.
- scan electrode drive circuit 33 when the downward ramp waveform voltage is applied to scan electrode SC1 through scan electrode SCn.
- the above voltage waveform is a forced initializing waveform that generates an initializing discharge in the discharge cell regardless of the operation of the immediately preceding subfield.
- the operation for applying the forced initialization waveform to scan electrode SC1 through scan electrode SCn is the forced initialization operation.
- the forced initialization operation in the initialization period of the forced initialization subfield (subfield SF1) is completed.
- the initializing discharge is forcibly generated in all the discharge cells in the image display area of the panel 10, and the wall charge necessary for the address discharge generated in the subsequent address period Tw1 is obtained. Formed on each electrode.
- scan electrode drive circuit 33 when (voltage Vp ⁇ voltage Va) is applied to scan electrode SC1 through scan electrode SCn will be described.
- the transistor Q63 is turned on, and the voltage at the node B is clamped to the voltage 0 (V). As a result, the voltage at the node A is clamped to a negative voltage ( ⁇ Va).
- scan electrode drive circuit 33 when (voltage Vp ⁇ voltage Va) is applied to scan electrode SC1 through scan electrode SCn.
- a negative scan pulse with a negative voltage ( ⁇ Va) is applied to the first (first row) scan electrode SC1 from the top in terms of arrangement.
- a positive address pulse of a positive voltage Vd is applied to the data electrode Dk of the discharge cell that should emit light in the first row of the data electrodes D1 to Dm.
- the transistor QH1 is turned off and the transistor QL1 is turned on.
- sustain electrode SU1 since voltage Ve is applied to sustain electrode SU1 through sustain electrode SUn, sustain electrode SU1 in a region intersecting data electrode Dk is induced by a discharge generated between data electrode Dk and scan electrode SC1. Discharge also occurs between scan electrode SC1 and scan electrode SC1. Thus, address discharge is generated in the discharge cells (discharge cells to emit light) to which the scan pulse voltage Va and the address pulse voltage Vd are simultaneously applied.
- a positive wall voltage is accumulated on the scan electrode SC1
- a negative wall voltage is accumulated on the sustain electrode SU1
- a negative wall voltage is also accumulated on the data electrode Dk.
- the transistor QH1 is turned on, the transistor QL1 is turned off, and the voltage applied to the scan electrode SC1 is returned from the voltage ( ⁇ Va) to (voltage Vp ⁇ voltage Va), and the address operation in the discharge cells in the first row is completed.
- a scan pulse having a negative voltage ( ⁇ Va) is applied to the second scan electrode SC2 from the top (second row) in terms of arrangement, and data corresponding to the discharge cell to emit light in the second row.
- An address pulse of voltage Vd is applied to the electrode Dk.
- the transistor QH2 may be turned off and the transistor QL2 may be turned on.
- address discharge occurs in the discharge cells in the second row to which the scan pulse and address pulse are simultaneously applied.
- the address operation in the discharge cells in the second row is performed.
- the transistor Q63 is turned off, the transistors Q52 and Q59 are turned on, and the voltage at the node A is clamped to the voltage 0 (V). Then, the transistors QH1 to QHn are turned off, the transistors QL1 to QLn are turned on, and the voltage 0 (V) that is the voltage of the node A is applied to the scan electrodes SC1 to SCn.
- the writing period Tw1 of the subfield SF1 ends.
- address discharge is selectively generated in the discharge cells to emit light, and wall charges for sustain discharge are formed in the discharge cells.
- voltage Ve applied to sustain electrode SU1 through sustain electrode SUn in the latter half of initialization period Ti1 and voltage Ve applied to sustain electrode SU1 through sustain electrode SUn in the address period may have different voltage values.
- the voltage 0 (V) is applied to the sustain electrodes SU1 to SUn. Then, sustain pulse of positive voltage Vs is applied to scan electrode SC1 through scan electrode SCn.
- the voltage difference between the scan electrode SCi and the sustain electrode SUi exceeds the discharge start voltage, and is maintained between the scan electrode SCi and the sustain electrode SUi. Discharge occurs.
- the phosphor layer 25 of the discharge cell in which the sustain discharge has occurred emits light by the ultraviolet rays generated by the sustain discharge.
- a negative wall voltage is accumulated on scan electrode SCi
- a positive wall voltage is accumulated on sustain electrode SUi.
- a positive wall voltage is also accumulated on the data electrode Dk.
- the sustain discharge does not occur in the discharge cells in which the address discharge has not occurred in the address period Tw1.
- sustain pulses of the number obtained by multiplying the luminance weight by a predetermined luminance multiple are alternately applied to scan electrode SC1 through scan electrode SCn and sustain electrode SU1 through sustain electrode SUn.
- the discharge cells that have generated the address discharge in the address period Tw1 generate the number of sustain discharges corresponding to the luminance weight, and emit light with the luminance corresponding to the luminance weight.
- scan electrode drive circuit 33 when this upward ramp waveform voltage is applied to scan electrode SC1 through scan electrode SCn will be described.
- the transistors Q52 and Q59 are turned on, and the voltage at the node A is clamped to a voltage of 0 (V). Then, the transistors QH1 to QHn are turned off, the transistors QL1 to QLn are turned on, and the voltage 0 (V) that is the voltage of the node A is applied to the scan electrodes SC1 to SCn.
- the transistor Q52 is turned off. Then, a current is supplied to the transistor Q55 through the resistor R55, and the Miller integrating circuit of the upward waveform generating circuit 55 is operated. As a result, the voltage at the node A gradually increases from the voltage 0 (V) toward the voltage Vr. A voltage at node A is applied to scan electrode SC1 through scan electrode SCn via transistor QL1 through transistor QLn. Therefore, an upward ramp waveform voltage that gently rises from voltage 0 (V) toward voltage Vr can be applied to scan electrode SC1 through scan electrode SCn.
- the sustain of the discharge cell that has generated the sustain discharge is maintained while the rising ramp waveform voltage applied to scan electrode SC1 through scan electrode SCn exceeds the discharge start voltage.
- a weak discharge (erase discharge) is continuously generated between the electrode SUi and the scan electrode SCi.
- the charged particles generated by this weak discharge are accumulated as wall charges on the sustain electrode SUi and the scan electrode SCi so as to reduce the voltage difference between the sustain electrode SUi and the scan electrode SCi.
- the wall voltage on scan electrode SCi and the wall voltage on sustain electrode SUi are weakened while the positive wall voltage on data electrode Dk remains.
- unnecessary wall charges in the discharge cell are erased.
- sustain period Ts1 of subfield SF1 ends.
- the voltage 0 (V) is applied to the data electrodes D1 to Dm, and the voltage Ve is applied to the sustain electrodes SU1 to SUn.
- the down-slope waveform voltage that falls at the same gradient as the down-slope waveform voltage generated during the forced initialization period is applied to scan electrode SC1 through scan electrode SCn from a voltage that is less than the discharge start voltage toward negative voltage Vi.
- the voltage Vi is set to a voltage exceeding the discharge start voltage.
- scan electrode drive circuit 33 when applying this downward ramp waveform voltage to scan electrode SC1 through scan electrode SCn will be described.
- the transistor Q52 and the transistor Q59 are turned on, and the voltage at the node A is clamped to the voltage 0 (V). Then, the transistors QH1 to QHn are turned off, the transistors QL1 to QLn are turned on, and the voltage 0 (V) that is the voltage of the node A is applied to the scan electrodes SC1 to SCn.
- the transistor Q52 and the transistor Q59 are turned off. Then, a current is supplied to the transistor Q62 through the resistor R62, and the Miller integrating circuit of the downward waveform generating circuit 60 is operated. As a result, the voltage at node B gradually drops from (voltage 0 (V) + voltage Va) toward voltage 0 (V), and the voltage at node A changes from voltage 0 (V) to a negative voltage ( ⁇ Va). Descent gently toward A voltage at node A is applied to scan electrode SC1 through scan electrode SCn via transistor QL1 through transistor QLn. Therefore, it is possible to apply a downward ramp waveform voltage that gently drops from voltage 0 (V) to negative voltage ( ⁇ Va) to scan electrode SC1 through scan electrode SCn.
- the negative wall voltage on scan electrode SCi and the positive wall voltage on sustain electrode SUi are weakened.
- an excessive portion of the positive wall voltage on the data electrode Dk is discharged.
- the wall voltage in the discharge cell is adjusted to a wall voltage suitable for the address operation in the address period.
- the above voltage waveform is a selective initialization waveform in which an initializing discharge is selectively generated in a discharge cell that has performed an address operation in the address period (here, address period Tw1) of the immediately preceding subfield.
- the operation of applying the selective initialization waveform to scan electrode SC1 through scan electrode SCn is the selective initialization operation.
- the same drive voltage waveform as that in the address period Tw1 of the subfield SF1 is applied to each electrode.
- the number of sustain pulses corresponding to the luminance weight is alternately applied to scan electrode SC1 through scan electrode SCn and sustain electrode SU1 through sustain electrode SUn.
- each subfield after subfield SF3 the same drive voltage waveform as in subfield SF2 is applied to each electrode except for the number of sustain pulses generated in the sustain period.
- the gradient of the rising ramp waveform voltage is about 1.3 V / ⁇ sec, and the gradient of the falling ramp waveform voltage is about ⁇ 1.5 V / ⁇ sec.
- the specific numerical values such as the voltage value and gradient described above are merely examples, and the present invention is not limited to the numerical values described above for each voltage value and gradient.
- Each voltage value, gradient, and the like are preferably set optimally based on the discharge characteristics of the panel and the specifications of the plasma display device.
- subfield SF1 is a forced initialization subfield for performing a forced initialization operation
- other subfields are a selective initialization subfield for performing a selective initialization operation
- the present invention is not limited to this configuration.
- the subfield SF1 may be a selective initialization subfield and other subfields may be forced initialization subfields, or a plurality of subfields may be forced initialization subfields.
- scan electrode drive circuit 33 in the present embodiment includes scan pulse generation circuit 40, sustain pulse generation circuit 50, upstream waveform generation circuit 55, and downstream waveform generation circuit 60.
- Sustain pulse generation circuit 50 generates a sustain pulse by displacing the potential of node A, which is the reference potential of scan pulse generation circuit 40, between voltage Vs and voltage 0 (V).
- the upward waveform generation circuit 55 gently increases the potential of the node A toward the voltage Vr to generate an upward slope waveform voltage.
- the downward waveform generation circuit 60 generates a downward ramp waveform voltage by gently dropping the potential of the node A toward the negative voltage ( ⁇ Va).
- the scan pulse generation circuit 40 includes a first power supply E41, transistors QH1 to QHn, and transistors QL1 to QLn.
- the first power supply E41 superimposes the positive voltage Vp on the potential of the node A.
- the transistors QH1 to QHn are high-voltage transistors that output the voltage on the high-voltage side of the first power supply E41, that is, the voltage obtained by superimposing the positive voltage Vp on the potential of the node A to each of the scan electrodes SC1 to SCn. .
- the transistors QL1 to QLn are low voltage transistors that output the voltage on the low voltage side of the first power supply E41, that is, the voltage at the node A, to each of the scan electrodes SC1 to SCn.
- the downstream waveform generation circuit 60 includes a transistor Q63, a second power supply E61, and a Miller integration circuit.
- the second power supply E61 superimposes the voltage Va on the potential of the node A.
- Transistor Q63 has one terminal connected to node B on the high voltage side of second power supply E61 and the other terminal connected to voltage 0 (V), which is the ground potential.
- the transistor Q63 clamps the voltage on the high voltage side of the second power supply E61 to the voltage 0 (V), thereby clamping the voltage at the node A to the negative voltage ( ⁇ Va).
- the Miller integrating circuit of the downstream waveform generating circuit 60 one terminal is connected to the node B, and the other terminal is connected to the voltage 0 (V) which is the ground potential.
- This Miller integrating circuit gradually lowers the potential of the node B toward the voltage 0 (V), thereby lowering the potential of the node A toward the negative voltage ( ⁇ Va). Generate voltage.
- the downstream waveform generating circuit 60 is configured as described above, so that the transistor Q62 of the Miller integrating circuit and the transistor Q63 connected in parallel to the transistor Q62 are not power supplies that generate a negative voltage.
- a negative voltage ( ⁇ Va) scan pulse and a falling ramp waveform voltage that decreases toward the negative voltage Vi can be generated. That is, the down waveform generation circuit 60 can be configured with a simple configuration as shown in FIG. 4 without using a power source that generates a negative voltage.
- an overvoltage detection circuit for the first power supply E41 and the second power supply E61 can be simply configured.
- the overvoltage detection circuit is a circuit that detects when the voltage generated by the first power supply E41 or the second power supply E61 is higher than the set voltage, and is a protection circuit in the scan electrode drive circuit 33. .
- FIG. 6 is a diagram schematically showing a configuration example of an overvoltage detection circuit in the scan electrode drive circuit 33 of the plasma display device 30 in one embodiment of the present invention. In FIG. 6, only the circuit relating to the overvoltage detection circuit is shown, and other circuits are omitted.
- the overvoltage detection circuit shown in FIG. 6 is an overvoltage detection circuit for the first power supply E41 and the second power supply E61.
- the overvoltage detection circuit has a resistance dividing circuit 70 and a comparison circuit 80.
- the resistance dividing circuit 70 includes a resistor R71, a resistor R72, a resistor R73, a diode Di71, and a diode Di72.
- Resistance R71, resistance R72, and resistance R73 are connected in series. One terminal of the resistor R73 is connected to the node A, and the other terminal of the resistor R73 is connected to one terminal of the resistor R72.
- node D a connection point between the resistor R73 and the resistor R72 is referred to as “node D”.
- the other terminal of the resistor R72 is connected to one terminal of the resistor R71, and the other terminal of the resistor R71 is connected to a terminal on the high voltage side of the second power supply E61 via a diode Di71 for backflow prevention. Therefore, a voltage obtained by superimposing the voltage Va on the voltage at the node A is applied to the other terminal of the resistor R71.
- node C the connection point between the resistor R72 and the resistor R71 is referred to as “node C”.
- a node on the high voltage side of the first power supply E41 is connected to a node C which is a connection point between the resistor R72 and the resistor R71 via a diode Di72 for preventing backflow. Therefore, a voltage obtained by superimposing the voltage Vp on the voltage at the node A is applied to the node C.
- the high-voltage side terminal of the second power source E61 is connected to the resistor R71, and the low-voltage side terminal of the second power source E61 is connected to the resistor R73. Therefore, the voltage at the node C is a voltage obtained by dividing the voltage Va, which is the output voltage of the second power supply E61, by the resistor R71, the resistor R72, and the resistor R73.
- the resistance values of the resistor R71, the resistor R72, and the resistor R73 are set so that the voltage at the node C is substantially equal to the voltage Vp that is the output voltage of the first power supply E41.
- the voltage at the node D is a voltage obtained by dividing the voltage Vp, which is the output voltage of the first power supply E41, by the resistors R72 and R73.
- the comparison circuit 80 includes a Zener diode Di81, a transistor Q81, a photocoupler PC85, and a resistor R86.
- the anode of the Zener diode Di81 is connected to the base of the transistor Q81, and the cathode is connected to the node D.
- the emitter of the transistor Q81 is connected to the node A, and the collector of the transistor Q81 is connected to the light emitting diode Di85 of the photocoupler PC85.
- the voltage at the node D at which the transistor Q81 is turned on is referred to as “threshold voltage”.
- the transistor Q81 is not turned on and no current flows through the phototransistor Q85.
- the voltage output from the circuit 80 is voltage 0 (V) (low level).
- the voltage at the node D does not exceed the Zener voltage of the Zener diode Di81.
- the resistance values of the resistor R71, the resistor R72, and the resistor R73 are set so that the transistor Q81 is not turned on. Therefore, if the output voltage of the first power supply E41 and the output voltage of the second power supply E61 are both normal voltages, the voltage at the node D is less than the “threshold voltage”, and the overvoltage detection signal SOS output from the comparison circuit 80. Is a voltage 0 (V) (low level).
- the output voltage of the second power supply E61 rises above the normal voltage
- the backflow of the current to the first power supply E41 is prevented by the action of the diode Di72 for backflow prevention, so the voltage at the node D rises.
- the transistor Q81 is turned on, and the overvoltage detection signal SOS output from the comparison circuit 80 becomes high level.
- the output voltage of the first power supply E41 rises above the normal voltage
- the backflow of current to the second power supply E61 is prevented by the action of the diode Di71 for backflow prevention, so the voltage at the node D rises.
- the transistor Q81 is turned on, and the overvoltage detection signal SOS output from the comparison circuit 80 becomes high level.
- the voltage at the node D increases.
- the voltage at the node D rises above a predetermined “threshold voltage” determined by the Zener diode Di81 and the transistor Q81, the transistor Q81 is turned on. Accordingly, the light emitting diode Di85 of the photocoupler PC85 emits light, the phototransistor Q85 is turned on, and the overvoltage detection signal SOS becomes high level.
- the scan electrode drive circuit 33 includes an overvoltage detection circuit that detects an overvoltage when the output voltage of the first power supply E41 or the second power supply E61 becomes an overvoltage. .
- the overvoltage detection circuit divides the output voltage Va of the second power supply E61 by the resistors R71, R72, and R73 so that a voltage equal to the voltage Vp of the first power supply E41 is generated at the node C. Then, the voltage Vp of the first power supply E41 is connected to the node C via the diode Di72. Then, the voltage at the node D obtained by resistance-dividing the voltage at the node C is compared with a predetermined “threshold voltage”.
- the scan electrode drive circuit 33 can detect the overvoltage by one overvoltage detection circuit.
- the resistance dividing circuit is configured as shown in FIG. did.
- the connection point of the output terminal of the first power supply E41 and the connection point of the output terminal of the second power supply E61 are shown in FIG. What is necessary is just to make it the structure replaced with the structure shown.
- each resistance value of resistance R71, resistance R72, and resistance R73 which comprise a resistance division circuit should just be set so that the voltage of the node C may become a voltage equal to the output voltage of the 2nd power supply E61.
- the voltage at the node D obtained by resistance-dividing the voltage at the node C is compared with a predetermined “threshold voltage”, whereby the output voltage of the first power supply E41 or the output voltage of the second power supply E61.
- An overvoltage detection circuit was configured to detect the overvoltage.
- the present invention is not limited to this configuration.
- the overvoltage detection circuit is configured to compare the “threshold voltage” set so that the overvoltage can be detected when the voltage at the node C becomes an overvoltage with the voltage at the node C. It may be configured.
- the scan electrode drive circuit 33 in the present embodiment may include an overvoltage detection circuit having the following configuration.
- the overvoltage detection circuit is configured to resistively divide the output voltage of the power supply with the higher output voltage of the first power supply E41 and the second power supply E61, and to generate a voltage equal to the voltage of the power supply with the lower output voltage.
- a comparison circuit In the resistor divider circuit, the output terminal of the power supply having the lower output voltage is connected to the node C where the voltage equal to the voltage of the power supply having the lower output voltage is generated via a diode for preventing backflow.
- the comparison circuit the voltage at the node C or the voltage at the node D obtained by resistance-dividing the voltage at the node C is compared with a predetermined “threshold voltage”. Then, the comparison circuit is configured so that the overvoltage detection signal SOS becomes high level when the output voltage of the first power supply E41 or the output voltage of the second power supply E61 becomes an overvoltage. Thus, the overvoltage of the first power supply E41 or the second power supply E61 is detected. In the present embodiment, the overvoltage of the first power supply E41 and the second power supply E61 can be detected by one overvoltage detection circuit in this way.
- the reference potential in the scan electrode driving circuit 33 is the potential at the node A, and the reference potential of the circuit that receives the overvoltage detection signal SOS is the ground potential (voltage 0 (V)).
- the reference potential is different between the scan electrode drive circuit 33 and the circuit that receives the overvoltage detection signal SOS. Therefore, in this embodiment, the photocoupler PC85 is used for the comparison circuit 80, and two circuits having different reference potentials are connected via the photocoupler PC85.
- the number of subfields constituting one field, subfields to be forced initialization subfields, luminance weights of each subfield, and the like are not limited to the above-described numerical values. Moreover, the structure which switches a subfield structure based on an image signal etc. may be sufficient.
- the drive voltage waveform shown in FIG. 5 is merely an example in the embodiment of the present invention, and the present invention is not limited to this drive voltage waveform.
- circuit configurations shown in FIGS. 3, 4, and 6 are merely examples in the embodiment of the present invention, and the present invention is not limited to these circuit configurations.
- the specific numerical values shown in the embodiment of the present invention are set based on the characteristics of the panel 10 having a screen size of 50 inches and the number of display electrode pairs 14 of 1024. It is just an example.
- the present invention is not limited to these numerical values, and each numerical value is desirably set optimally in accordance with panel specifications, panel characteristics, plasma display device specifications, and the like. Each of these numerical values is allowed to vary within a range where the above-described effect can be obtained.
- the number of subfields constituting one field, the luminance weight of each subfield, etc. are not limited to the values shown in the embodiment of the present invention, and the subfield configuration is based on the image signal or the like. It may be configured to switch.
- the present invention is useful as a plasma display device because the number of parts constituting the scan electrode drive circuit can be suppressed and a scan electrode drive circuit having a simple configuration can be realized.
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Abstract
Description
図1は、本発明の一実施の形態におけるプラズマディスプレイ装置に用いるパネル10の構造を示す分解斜視図である。
11 前面基板
12 走査電極
13 維持電極
14 表示電極対
15,23 誘電体層
16 保護層
21 背面基板
22 データ電極
24 隔壁
25,25R,25G,25B 蛍光体層
30 プラズマディスプレイ装置
31 画像信号処理回路
32 データ電極駆動回路
33 走査電極駆動回路
34 維持電極駆動回路
35 タイミング発生回路
40 走査パルス発生回路
50 維持パルス発生回路
53 電力回収部
55 上り波形発生回路
60 下り波形発生回路
70 抵抗分割回路
80 比較回路
C55,C62 コンデンサ
R55,R62,R71,R72,R73,R86 抵抗
Di71,Di72 ダイオード
Di81 ツェナダイオード
Di85 発光ダイオード
Q85 フォトトランジスタ
PC85 フォトカプラ
Q51,Q52,Q55,Q59,Q62,Q63,Q81,QH1~QHn,QL1~QLn トランジスタ
E41 第1電源
E61 第2電源
SOS 過電圧検出信号
A,B,C,D 節点
Claims (2)
- 走査電極を有する放電セルを複数備えたプラズマディスプレイパネルと、
前記走査電極に駆動電圧波形を印加する走査電極駆動回路とを備え、
初期化期間、書込み期間、および維持期間を有するサブフィールドを複数用いて1フィールドを構成して前記プラズマディスプレイパネルに画像を表示するプラズマディスプレイ装置であって、
前記走査電極駆動回路は、
前記初期化期間に前記走査電極に印加する下り傾斜波形電圧を発生する下り波形発生回路と、
前記書込み期間に前記走査電極に印加する走査パルスを発生する走査パルス発生回路とを備え、
前記走査パルス発生回路は、
前記走査パルス発生回路の基準電位に重畳する正の電圧を発生する第1電源と、
前記第1電源の高圧側の電圧を複数の前記走査電極のそれぞれに出力する複数の高圧側トランジスタと、
前記第1電源の低圧側の電圧を複数の前記走査電極のそれぞれに出力する複数の低圧側トランジスタとを有し、
前記下り波形発生回路は、
前記基準電位に重畳する正の電圧を発生する第2電源と、
一方の端子が前記第2電源の高圧側に接続され、他方の端子が接地電位に接続されたミラー積分回路とを有し、負の電圧まで降下する下り傾斜波形電圧を発生する
ことを特徴とするプラズマディスプレイ装置。 - 前記走査電極駆動回路は、抵抗分割回路と比較回路とを有し、
前記抵抗分割回路は、前記第1電源および前記第2電源のうち出力電圧が高い方の電源の出力電圧を抵抗分圧して出力電圧が低い方の電源の電圧に等しい電圧を発生し、前記出力電圧が低い方の電源の電圧に等しい電圧が発生した節点に、前記出力電圧が低い方の電源の出力端子を、逆流防止用のダイオードを介して接続し、
前記比較回路においては、前記節点の電圧、または前記節点の電圧を抵抗分圧した電圧を所定の閾値電圧と比較し、前記第1電源または前記第2電源の過電圧を検出する
ことを特徴とする請求項1に記載のプラズマディスプレイ装置。
Priority Applications (4)
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KR1020137020272A KR20130098435A (ko) | 2011-02-24 | 2012-02-22 | 플라즈마 디스플레이 장치 |
JP2013500889A JPWO2012114735A1 (ja) | 2011-02-24 | 2012-02-22 | プラズマディスプレイ装置 |
CN2012800049290A CN103299357A (zh) | 2011-02-24 | 2012-02-22 | 等离子显示装置 |
US13/983,531 US20130313981A1 (en) | 2011-02-24 | 2012-02-22 | Plasma display device |
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JP2011-038067 | 2011-02-24 |
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JP (1) | JPWO2012114735A1 (ja) |
KR (1) | KR20130098435A (ja) |
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JP2010175771A (ja) * | 2009-01-29 | 2010-08-12 | Panasonic Corp | プラズマディスプレイ装置 |
JP2011191235A (ja) * | 2010-03-16 | 2011-09-29 | Hitachi Automotive Systems Ltd | 電圧異常検出回路 |
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KR100390887B1 (ko) * | 2001-05-18 | 2003-07-12 | 주식회사 유피디 | 교류형 플라즈마 디스플레이 패널의 구동회로 |
EP1449191A1 (en) * | 2001-11-30 | 2004-08-25 | Matsushita Electric Industrial Co., Ltd. | Suppression of vertical crosstalk in a plasma display panel |
KR20060086767A (ko) * | 2005-01-27 | 2006-08-01 | 엘지전자 주식회사 | 플라즈마 표시 패널의 에너지 회수 회로 |
US7808452B2 (en) * | 2005-07-14 | 2010-10-05 | Panasonic Corporation | Plasma display panel driving method and plasma display device |
CN101356560B (zh) * | 2006-08-10 | 2010-12-29 | 松下电器产业株式会社 | 等离子显示装置以及等离子显示面板的驱动方法 |
JP2009192779A (ja) * | 2008-02-14 | 2009-08-27 | Panasonic Corp | プラズマディスプレイ装置およびプラズマディスプレイパネルの駆動方法 |
CN101727822B (zh) * | 2008-12-29 | 2011-12-07 | 四川虹欧显示器件有限公司 | 用于等离子显示器的扫描电极驱动电路和驱动方法 |
JP5169960B2 (ja) * | 2009-04-08 | 2013-03-27 | パナソニック株式会社 | プラズマディスプレイパネルの駆動方法およびプラズマディスプレイ装置 |
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- 2012-02-22 JP JP2013500889A patent/JPWO2012114735A1/ja active Pending
- 2012-02-22 CN CN2012800049290A patent/CN103299357A/zh active Pending
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JP2010175771A (ja) * | 2009-01-29 | 2010-08-12 | Panasonic Corp | プラズマディスプレイ装置 |
JP2011191235A (ja) * | 2010-03-16 | 2011-09-29 | Hitachi Automotive Systems Ltd | 電圧異常検出回路 |
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JPWO2012114735A1 (ja) | 2014-07-07 |
US20130313981A1 (en) | 2013-11-28 |
KR20130098435A (ko) | 2013-09-04 |
CN103299357A (zh) | 2013-09-11 |
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