JP5061777B2 - Plasma display apparatus and driving method of plasma display panel - Google Patents

Description

  The present invention relates to a plasma display device and a plasma display panel driving method used for a wall-mounted television or a large monitor.

  A typical AC surface discharge type panel as a plasma display panel (hereinafter abbreviated as “panel”) is formed of three discharge cells that emit light in red (R), green (G), and blue (B) colors. Display pixels are arranged in a matrix.

  In recent years, the plasma display device provided with such a panel has not only been used for television broadcasting and viewing of reproduced moving images, but has been expanded to various other fields. For example, taking advantage of the good visibility of a panel, a large screen, and high definition, a plasma display device has been used as a display medium for advertisements and announcements.

  When the plasma display device is used for display of advertisements, etc., not only normal installation (hereinafter, normal installation in which the long axis of the panel is horizontal with respect to the installation surface is referred to as “horizontal placement”). The plasma display device is installed vertically (hereinafter, the installation in which the long axis of the panel is vertical to the installation surface is referred to as “vertical installation”), and the image is displayed vertically. It may be displayed.

In view of this, in order to easily change the installation direction of the plasma display, a technique relating to an attachment device that can rotatably attach the plasma display device is disclosed (for example, see Patent Document 1).
JP 11-24577 A

  When performing advertisements or announcements using a plurality of plasma display devices, for example, one image is divided into a plurality of regions, enlarged and displayed on each of a plurality of plasma display devices installed adjacent to each other. A multi-screen that is displayed as a single image may be configured. In such a case, there is an extension of the image at the seam between adjacent plasma display devices (where the image cannot be displayed such as the outer frame that supports the panel, where the adjacent plasma display devices are adjacent to each other). A joint setting may be performed so that an image corresponding to a joint is not displayed so as not to cause the extension. Thereby, although a part of the image is deficient, it is possible to eliminate a gap between images and display a natural image on a multi-screen.

  However, at this time, when the non-display area of the image is set with a uniform width from the boundary line when dividing the image, the plasma display device installed at the left end, the plasma display device adjacent to the plasma display device, and the right display A difference occurs in the data amount of the image to be displayed between the plasma display device and the plasma display device adjacent thereto.

  For example, when a multi-screen is formed by dividing one image into three, if the data amount of the image in the non-display area of the image set with a predetermined width from the boundary line when dividing the image is Q, the left edge In the plasma display device installed at the right end, the data amount of the image in the non-display area is Q, but in the plasma display device installed in the center, the data amount of the image in the non-display area is 2Q. Accordingly, the data amount of the image to be displayed is reduced.

  In addition, if the position of the boundary line when dividing the image is set by taking into account the difference in the data amount of the non-display area in advance, this time, if the joint setting is not performed, the image displayed between the plasma display devices Difference in the amount of data. Alternatively, in order to equalize the data amount of the image to be displayed, the position of the boundary line must be moved between when the joint setting is performed and when it is not performed.

  The present invention has been made in view of such problems, and when configuring a multi-screen with a plurality of plasma display devices, without moving the position of the boundary line when dividing an image by joint setting, and An object of the present invention is to provide a plasma display device and a panel driving method capable of making image data amounts of images to be displayed equal to each other between plasma display devices constituting a multi-screen regardless of joint settings.

  The plasma display device of the present invention includes a panel in which display pixels formed from a plurality of discharge cells that emit light in red, green, and blue colors are arranged in a matrix in a row direction and a column direction, and an input image signal. The image data is converted into image data arranged in a matrix in the row direction and the column direction, and the image data is divided into at least three regions having boundaries in the column direction, and at least three image memories that can be arbitrarily written and read are used. An image signal processing unit that performs signal processing for displaying on a panel for a preselected one of the regions, and the image signal processing unit is provided with a plurality of plasma display devices arranged side by side. Divide the image into at least three areas and zoom in on the plasma display device corresponding to each area. A boundary between a leftmost region and a region adjacent to the leftmost region among at least three regions based on joint setting for setting whether to display an image of a portion corresponding to a joint of adjacent plasma display devices; and A non-display area that does not display an image is provided at a ratio of 2: 1 at the boundary between the right end area and the area adjacent to the right end area of at least three areas.

  As a result, when configuring a multi-screen by arranging multiple plasma display devices, the multi-screen can be configured without shifting the position of the boundary line when dividing the image by the joint setting and without depending on the joint setting. It is possible to make the image data amounts of the images to be displayed equal among the plasma display devices.

  In the plasma display device of the present invention, the image signal processing unit, when performing signal processing, the boundary between the left end region and the region adjacent to the left end region, and the region adjacent to the right end region and the right end region. A non-display area may be provided by providing an area that is not written to the image memory at a ratio of 2: 1.

  In the plasma display device of the present invention, the image signal processing unit, when performing signal processing, the boundary between the left end region and the region adjacent to the left end region, and the region adjacent to the right end region and the right end region. A non-display area may be provided by providing an area where image data is not read from the image memory at a ratio of 2: 1.

  Further, the panel driving method of the present invention includes a panel in which display pixels formed from a plurality of discharge cells emitting light of red, green, and blue are arranged in a matrix in the row direction and the column direction, and an input image The signal is converted into image data arranged in a matrix in the row direction and the column direction, and the image data is divided into at least three regions having boundaries in the column direction, and an image memory that can be arbitrarily written and read is used. A plasma display device driving method comprising: an image signal processing unit that performs signal processing for displaying on a panel with respect to a preselected one of at least three regions, wherein a plurality of plasma display devices are Installed side-by-side, divides one image into at least three areas and enlarges them on the plasma display device corresponding to each area In the multi-screen configuration, the left edge area and the left edge area of at least three areas based on the joint setting for setting whether to display an image corresponding to the joint of the adjacent plasma display devices And a non-display area that does not display an image is provided at a ratio of 2: 1 at the boundary between the right edge area and the area adjacent to the right edge area of at least three areas.

  As a result, when configuring a multi-screen by arranging multiple plasma display devices, the multi-screen can be configured without shifting the position of the boundary line when dividing the image by the joint setting and without depending on the joint setting. It is possible to make the image data amounts of the images to be displayed equal among the plasma display devices.

  In the panel driving method of the present invention, when signal processing is performed in the image signal processing unit, the boundary between the left end region and the region adjacent to the left end region, and the region adjacent to the right end region and the right end region A non-display area may be provided by providing an area that is not written to the image memory at a ratio of 2: 1.

  In the panel driving method of the present invention, when signal processing is performed in the image signal processing unit, the boundary between the left end region and the region adjacent to the left end region, and the region adjacent to the right end region and the right end region A non-display area may be provided by providing an area where image data is not read from the image memory at a ratio of 2: 1.

  According to the present invention, when a multi-screen is configured with a plurality of plasma display devices, the position of the boundary line when the image is divided is not moved by the joint setting, and the multi-screen is not used. It is possible to provide a plasma display device and a panel driving method capable of making the image data amounts of images to be displayed equal to each other among the plasma display devices constituting the display.

  Hereinafter, a plasma display device according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is an exploded perspective view showing the structure of panel 10 according to Embodiment 1 of the present invention. On the glass front plate 21, a plurality of display electrode pairs 24 including a pair of scanning electrodes 22 and sustain electrodes 23 are formed in parallel to each other. A dielectric layer 25 is formed so as to cover the scan electrode 22 and the sustain electrode 23, and a protective layer 26 is formed on the dielectric layer 25.

  The protective layer 26 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 MgO having excellent properties.

  A plurality of data electrodes 32 are formed in parallel with each other on the back plate 31, a dielectric layer 33 is formed so as to cover the data electrodes 32, and a grid-like partition wall 34 is formed thereon. A phosphor layer 35 that emits light of each color of red (R), green (G), and blue (B) is provided on the side surface of the partition wall 34 and on the dielectric layer 33.

  The front plate 21 and the back plate 31 are arranged to face each other so that the display electrode pair 24 and the data electrode 32 are three-dimensionally crossed with a minute discharge space interposed therebetween, and the outer periphery thereof is sealed with a sealing material such as glass frit. I wear it. In the internal discharge space, a mixed gas of neon and xenon is sealed as a discharge gas. In the present embodiment, a discharge gas having a xenon partial pressure of about 10% is used in order to improve luminous efficiency. The discharge space is partitioned into a plurality of sections by partition walls 34, and discharge cells are formed at the intersections between the display electrode pairs 24 and the data electrodes 32. Then, ultraviolet light is generated by gas discharge in each discharge cell, and phosphors of each color of R, G, and B are excited and emitted by this ultraviolet light, thereby performing color display of images.

  Note that the structure of the panel 10 is not limited to the above-described structure, and for example, the panel 10 may include a stripe-shaped partition wall. Further, the mixing ratio of the discharge gas is not limited to the above-described numerical values, and may be other mixing ratios.

  FIG. 2 is an electrode array diagram of panel 10 in accordance with the first exemplary embodiment of the present invention. In panel 10, n scanning electrodes SC1 to SCn (scanning electrode 22 in FIG. 1) and n sustaining electrodes SU1 to SUn (sustaining electrode 23 in FIG. 1) long in the row direction are arranged and long in the column direction. (3 × m) (hereinafter abbreviated as 3 × m = m ′) data electrodes D1 to Dm ′ (data electrodes 32 in FIG. 1) are arranged. A discharge cell is formed at a portion where a pair of scan electrode SCi (i = 1 to n) and sustain electrode SUi intersects one data electrode Dj (j = 1 to m ′), and the discharge cell is a discharge space. M ′ × n are formed therein.

  Next, a driving voltage waveform for driving the panel 10 and an outline of the operation will be described. In the plasma display device in this embodiment, one field period is divided into a plurality of subfields, and gradation display is performed by controlling light emission / non-light emission of each discharge cell for each subfield.

  FIG. 3 is a schematic waveform diagram showing a subfield configuration in the first embodiment of the present invention. FIG. 3 shows an outline of a drive waveform in one field period, and details of the drive voltage waveform will be described later.

  In this embodiment, one field period is divided into a plurality of subfields, for example, one field is divided into 10 subfields (first SF, second SF,. The panel 10 is driven by the subfield method for performing gradation display. Each subfield has an initialization period, an address period, and a sustain period. In the initializing period, initializing discharge is generated, and wall charges necessary for the subsequent address discharge are formed on each electrode. In the address period, an address pulse voltage is selectively applied to the discharge cells to be lit in the subsequent sustain period to generate an address discharge, thereby selectively forming wall charges. In the sustain period, a sustain pulse is alternately applied to the display electrode pair 24 to generate a sustain discharge in the discharge cell in which the address discharge is generated, thereby causing the phosphor layer 35 of the corresponding discharge cell to emit light. Display.

  This subfield method uses the principle that as the number of sustain discharges generated within one field period increases, the display cell (discharge cell used for image display) appears to emit light brighter, and is maintained. The brightness of the display image can be controlled by controlling the number of sustain pulses in the period.

  For example, the reference number of sustain pulses (hereinafter referred to as “luminance weight”) from the first SF to the 10th SF constituting one field is (1, 2, 3, 6, 11, 18, 30, 44, 60), respectively. 80), the number of sustain pulses from the first SF to the 10th SF is doubled (hereinafter, a proportional constant for multiplying the number of sustain pulses is referred to as “luminance magnification”) (2, 4, 6 , 12, 22, 36, 60, 88, 120, 160) or three times the luminance magnification (3, 6, 9, 18, 33, 54, 90, 132, 180, 240) Can be changed to 2 times or 3 times. As described above, in this embodiment, the brightness is adjusted by changing the luminance magnification to control the number of times of light emission in the sustain period.

  In the present embodiment, the number of subfields and the luminance weight of each subfield are not limited to the above values, and the subfield configuration may be switched based on an image signal or the like.

  In this embodiment, the luminance magnification is changed according to the average brightness (APL: Average Picture Level) of the image.

  FIG. 4 is a schematic diagram showing the relationship between APL and luminance magnification in Embodiment 1 of the present invention.

  In this embodiment, as shown in FIG. 4, the luminance magnification of the sustain pulse when displaying an image of 100% APL is set to 1 and the luminance magnification when displaying an image of APL 20% or less is set to 5 times. The luminance magnification is gradually increased from 1 to 5 times from% image display to APL 20% image display. In the present embodiment, the luminance magnification of 1 to 5 at this time is divided into 120 steps.

  Thus, the reason why the luminance magnification is increased as the APL of the image to be displayed is decreased is that a dark image can be displayed brighter by increasing the luminance magnification when the APL is low. .

  In addition, since an image with a high APL is an image with a high luminance value as a whole, even if the luminance magnification is increased and the peak luminance is increased, the dynamics of the image are not changed so much only by increasing the overall luminance. Furthermore, when the peak luminance is further increased in an image having a high APL, there is a problem that the power consumption increases accordingly. On the other hand, an image with a low APL often has a low luminance value as a whole, or an image in which a region with a high luminance value exists in a low overall luminance value. By increasing the luminance, the luminance difference between the dark portion and the bright portion can be further increased, and a more dynamic and powerful image can be displayed.

  That is, by changing the luminance magnification according to APL as shown in FIG. 4, it is possible to display a dynamic and powerful image while suppressing power consumption.

  Here, the maximum value of the luminance magnification is set to 5 times, but this merely sets an upper limit value in relation to the luminance weight, the pulse width of the sustain pulse, and the time length that can be assigned to the sustain period. It is not limited to this value. The maximum value of the luminance magnification and the relationship between the luminance magnification and the APL may be set optimally according to the panel characteristics, the specifications of the plasma display device, and the like.

  Next, details of the drive voltage waveform will be described. FIG. 5 is a waveform diagram of drive voltage applied to each electrode of panel 10 in the first exemplary embodiment of the present invention. FIG. 5 shows driving voltage waveforms of two subfields, that is, a subfield that performs the all-cell initializing operation and a subfield that performs the selective initializing operation. Further, scan electrode SCi, sustain electrode SUi, and data electrode Dk in the following represent electrodes selected from the respective electrodes based on image data.

  First, the first SF that performs the all-cell initialization operation will be described.

  In the first half of the initializing period of the first SF, 0 (V) is applied to each of the data electrodes D1 to Dm ′ and the sustain electrodes SU1 to SUn, and the scan electrodes SC1 to SCn start discharging to the sustain electrodes SU1 to SUn. A ramp waveform voltage that gently rises from a voltage Vi1 equal to or lower than the voltage toward a voltage Vi2 that exceeds the discharge start voltage is applied.

  While this ramp waveform voltage rises, weak initializing discharges are continuously generated between scan electrodes SC1 to SCn, sustain electrodes SU1 to SUn, and data electrodes D1 to Dm '. Negative wall voltage is accumulated on scan electrodes SC1 to SCn, and positive wall voltage is accumulated on data electrodes D1 to Dm ′ and sustain electrodes SU1 to SUn. The wall voltage above 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.

  In the latter half of the initialization period, positive voltage Ve1 is applied to sustain electrodes SU1 to SUn, 0 (V) is applied to data electrodes D1 to Dm ′, and sustain electrodes SU1 to SCn are applied to scan electrodes SC1 to SCn. A ramp waveform voltage that gently decreases from voltage Vi3 that is equal to or lower than the discharge start voltage to voltage Vi4 that exceeds the discharge start voltage is applied to SUn. During this time, weak initializing discharges are continuously generated between scan electrodes SC1 to SCn, sustain electrodes SU1 to SUn, and data electrodes D1 to Dm '. Then, the negative wall voltage above scan electrodes SC1 to SCn and the positive wall voltage above sustain electrodes SU1 to SUn are weakened, and the positive wall voltage above data electrodes D1 to Dm ′ is adjusted to a value suitable for the write operation. Is done. Thus, the all-cell initializing operation for performing the initializing discharge on all the discharge cells is completed.

  Note that, as shown in the initialization period of the second SF in FIG. 5, a drive voltage waveform in which the first half of the initialization period is omitted may be applied to each electrode. In this initializing operation, a weak initializing discharge occurs in a discharge cell that has undergone a sustain discharge in the sustain period of the immediately preceding subfield, and a discharge cell that has not caused a sustain discharge in the immediately preceding subfield does not discharge. The wall charges at the end of the initialization period of the previous subfield are maintained as they are. Thus, the initializing operation in which the first half is omitted is a selective initializing operation in which initializing discharge is performed on the discharge cells in which the sustaining operation has been performed in the sustain period of the immediately preceding subfield. In addition, by selectively performing the initializing discharge on the discharge cell that has undergone the sustain discharge in the immediately preceding subfield, it is possible to reduce light emission not related to gradation display as much as possible and improve the contrast ratio.

  In the subsequent address period, voltage Ve2 is first applied to sustain electrodes SU1 to SUn, and voltage Vc is applied to scan electrodes SC1 to SCn.

  Then, a negative scan pulse voltage Va is applied to the scan electrode SC1 in the first row, and the data electrode Dk (k = 1 to m ′) of the discharge cell to be emitted in the first row among the data electrodes D1 to Dm ′. A positive write pulse voltage Vd is applied to. Thereby, a discharge is generated between data electrode Dk and scan electrode SC1, and this discharge is triggered to generate a discharge between sustain electrode SU1 and scan electrode SC1 in a region intersecting with data electrode Dk. . Thus, an address discharge occurs in the discharge cell to emit light, a positive wall voltage is accumulated on scan electrode SC1, a negative wall voltage is accumulated on sustain electrode SU1, and a negative wall voltage is also accumulated on data electrode Dk. Accumulated.

  On the other hand, no address discharge occurs at the intersections between the data electrodes D1 to Dm ′ to which the address pulse voltage Vd is not applied and the scan electrode SC1. The above address operation is performed until the discharge cell in the nth row, and the address period ends.

  In the subsequent sustain period, first, positive sustain pulse voltage Vs is applied to scan electrodes SC1 to SCn, and 0 (V) is applied to sustain electrodes SU1 to SUn. Then, in the discharge cell in which the address discharge has occurred, a sustain discharge occurs between scan electrode SCi and sustain electrode SUi, and phosphor layer 35 emits light due to the ultraviolet rays generated at this time. Then, a negative wall voltage is accumulated on scan electrode SCi, and a positive wall voltage is accumulated on sustain electrode SUi. Further, a positive wall voltage is accumulated on the data electrode Dk. In the discharge cells in which no address discharge has occurred during the address period, no sustain discharge occurs, and the wall voltage at the end of the initialization period is maintained.

  Subsequently, 0 (V) is applied to scan electrodes SC1 to SCn, and sustain pulse voltage Vs is applied to sustain electrodes SU1 to SUn. Then, the sustain discharge occurs again in the discharge cell in which the sustain discharge has occurred, the negative wall voltage is accumulated on the sustain electrode SUi, and the positive wall voltage is accumulated on the scan electrode SCi. Thereafter, similarly, the sustain electrodes of the number obtained by multiplying the luminance weight by the luminance magnification are alternately applied to the scan electrodes SC1 to SCn and the sustain electrodes SU1 to SUn, and a potential difference is given between the electrodes of the display electrode pair 24, thereby writing. The sustain discharge is continuously performed in the discharge cell that has caused the address discharge in the period.

  At the end of the sustain period, a ramp waveform voltage that gradually increases from 0 (V) toward voltage Vers is applied to scan electrodes SC1 to SCn. As a result, a weak erasure discharge is continuously generated, and part or all of the wall voltage on the scan electrode SCi and the sustain electrode SUi is erased while leaving the positive wall voltage on the data electrode Dk.

  Subsequent subfield operations are substantially the same as those described above except for the number of sustain pulses in the sustain period, and thus description thereof is omitted. The above is the outline of the drive voltage waveform applied to each electrode of panel 10 in the present embodiment.

  Next, the configuration of the plasma display device in the present embodiment will be described. FIG. 6 is a circuit block diagram of the plasma display device in accordance with the first exemplary embodiment of the present invention. The plasma display apparatus 1 includes a panel 10, an image signal processing circuit 41, a data electrode drive circuit 42, a scan electrode drive circuit 43, a sustain electrode drive circuit 44, a timing generation circuit 45, and a power supply circuit that supplies necessary power to each circuit block. (Not shown).

  An image signal processing circuit 41 serving as an image signal processing unit converts the input image signal sig into image data corresponding to the number of pixels of the panel 10. For example, when the plasma display device 1 is used in a normal landscape orientation, the image signal processing circuit 41 performs image data based on the input image signal sig (for example, if the image signal sig is in a so-called 525p format, Matrix-like image data (for example, image data of 1920 pixels in the row direction × 1080 pixels in the column direction) based on the number of display pixels of the panel 10 is generated from (720 pixels in the direction × 480 pixels in the column direction). In the present embodiment, the plasma display apparatus 1 can be used in a vertical position. However, when the plasma display apparatus 1 is used in a vertical position, the image signal processing circuit 41 is configured to input the input image. The image data of a predetermined area is once cut out from the image data based on the signal, the cut out image data is enlarged according to the number of display pixels of the panel 10, and then the enlarged image data is rotated by 90 degrees. Details of this series of processing will be described later. Since one display pixel is composed of three discharge cells of R, G, and B, one image data is light emission for each subfield of each of the R, G, and B discharge cells that form one display pixel.・ Has information on non-light emission.

  The image signal processing circuit 41 has an APL detection unit 47, and the APL detection unit 47 uses a generally known method such as accumulating the luminance value of the input video signal over one field period or one frame period. Thus, the APL representing the average brightness of the image is detected. Further, the image signal processing circuit 41 calculates the luminance magnification shown in FIG. 4 based on the detected APL.

  The timing generation circuit 45 generates various timing signals for controlling the operation of each circuit block on the basis of the horizontal synchronization signal H, the vertical synchronization signal V, and the luminance magnification output from the image signal processing circuit 41. Supply to block.

  In the present embodiment, the plasma display device 1 can be used in a vertical position, and one plasma image can be obtained by arranging three plasma display devices 1 in a vertical position. It is possible to configure a multi-screen that is enlarged and displayed in three parts. Then, the timing generation circuit 45 outputs a timing signal corresponding to the installation direction of the plasma display device 1 to the data electrode drive circuit 42, the scan electrode drive circuit 43, and the sustain electrode drive circuit 44.

  The data electrode drive circuit 42 converts the image data for each subfield into a signal corresponding to each data electrode D1 to Dm ', and drives each data electrode D1 to Dm'.

  Scan electrode driving circuit 43 applies an initialization waveform generator (not shown) for generating an initialization waveform voltage to be applied to scan electrodes SC1 to SCn in the initialization period, and applies to scan electrodes SC1 to SCn in the sustain period. A sustain pulse generator (not shown) for generating a sustain pulse, and a scan pulse generator (not shown) for generating a scan pulse voltage to be applied to scan electrodes SC1 to SCn in the address period, Each of the scan electrodes SC1 to SCn is driven based on the signal. Sustain electrode drive circuit 44 includes a sustain pulse generator (not shown) and a circuit for generating voltage Ve1 and voltage Ve2, and drives sustain electrodes SU1 to SUn based on a timing signal.

  Next, a configuration when the plasma display device 1 in the present embodiment is placed vertically will be described.

  FIG. 7 is a schematic diagram showing an example of image display when the plasma display device according to Embodiment 1 of the present invention is placed vertically. Note that the two broken lines shown on the panel 10 placed horizontally in FIG. 7 are auxiliary lines for clearly showing the configuration of dividing the screen into three, and are not displayed on the actual display screen.

  As shown in FIG. 7, in the present embodiment, a normal image displayed when the plasma display device 1 is placed horizontally is divided into three in the column direction (vertical direction in the drawing), one of which is For example, the center image of the three divided images can be enlarged and displayed on the plasma display device 1 placed vertically.

  As described above, when the plasma display device 1 is used in a vertical position, an image that is vertically long by rotating the camera 90 degrees or the like at the time of photographing is used as an image to be displayed on the plasma display device 1 that is vertically placed. It was necessary to prepare in advance.

  However, in the present embodiment, a normal horizontally long image can be divided into three parts, and one of them can be extracted and displayed in an enlarged manner, so that not only a dedicated image photographed for vertical placement but also FIG. As shown, even a normal landscape image can be displayed and used on the plasma display device 1 placed vertically.

  FIG. 8 is a schematic diagram showing an example of image display when three plasma display devices placed vertically are installed side by side in Embodiment 1 of the present invention.

  As shown in FIG. 8, in this embodiment, three plasma display devices placed vertically are arranged side by side, and a normal image displayed when placed horizontally is displayed in the column direction (vertical direction in the drawing). It is also possible to divide the image into three and display each image in an enlarged manner on each of the three plasma display devices 1 placed vertically. As a result, a multi-screen can be configured in which a single image is divided into three parts and enlarged and displayed by three plasma display devices arranged side by side.

  Next, an operation when the plasma display device in the present embodiment is placed vertically will be described.

  FIG. 9 is a flowchart showing an example of operation steps of the plasma display device 1 in the first exemplary embodiment of the present invention.

  As shown in FIG. 9, the installer first selects whether to place the plasma display device 1 vertically or horizontally (S1). This setting can be performed using, for example, a so-called remote controller used for remotely operating the plasma display device 1. As a more specific example, various settings of the plasma display device 1 can be performed using the remote controller. This can be done by opening an installation direction setting screen for selecting an installation direction from a menu screen for setting, and setting whether or not to place it vertically (not shown). At this time, by setting the initial setting in the plasma display device 1 horizontally, it is possible to perform this setting only when the plasma display device 1 is placed vertically.

  If the horizontal setting is made in step S1 (No in step S1), the plasma display device 1 performs a normal operation of displaying the input image signal on the panel 10 as it is (S2).

  If the vertical setting is set in step S1 (Yes in step S1), it is subsequently selected whether or not to cut out an image (S3). For example, when a vertically dedicated image prepared for the vertically placed plasma display device 1 is displayed, the image is not cut out (No in step S3), and the process proceeds to step S2 to input image signal. Is displayed on the panel 10 as it is.

  If the selection to cut out the image is made in step S3 (Yes in step S3), which of the images divided into three in the column direction shown in FIG. Is selected (S4). This setting can be performed, for example, using a remote controller in the same manner as in step S1. As a more specific example, a display image can be displayed from a menu screen for performing various settings of the plasma display device 1 using the remote controller. This can be done by opening a display image selection screen for selection and selecting any one of “right, center, left” (not shown). At this time, if the initial setting in the plasma display apparatus 1 is set to “center”, it is possible to perform this setting only when selecting the right end or left end image of the three divided images.

  Subsequently, it is selected whether to use the plasma display device 1 alone or to arrange a plurality of (here, three) plasma screens to form a multi-screen (S5).

  Subsequently, image data corresponding to the image selected in step S4 is cut out from the image data generated based on the input image signal sig, and an enlargement process corresponding to the number of display pixels on the panel 10 is performed. Further, the enlarged image data is rotated by 90 degrees, and the vertical direction of the vertically placed plasma display device 1 is aligned with the vertical direction of the displayed image (S6). This series of processing of cutting out, enlarging, and rotating the image data is performed by writing / reading image data to / from a semiconductor memory element (for example, RAM: Random Access Memory, not shown) included in the image signal processing circuit 41. This can be done by controlling, but the details will be described later. Note that in this embodiment mode, a configuration in which image data processing is performed using a semiconductor storage element such as a so-called RAM has been described; however, for example, a configuration using a magnetic storage device, an optical storage device, or the like may be used.

  Subsequently, the joint is turned on / off (S7). This joint refers to a joint of adjacent plasma display devices 1 when three plasma display devices 1 placed in a vertical arrangement are arranged to form a multi-screen (where a portion such as an outer frame of a panel that cannot display an image is adjacent to each other) ). FIG. 10 is a schematic diagram for explaining on / off of joint setting in the first embodiment of the present invention. For example, when the joint setting is turned on, as shown in the upper diagram of FIG. 10, an image corresponding to the seam of the adjacent plasma display devices 1 is not displayed. Image display can be performed. When the joint setting is turned off, as shown in the lower diagram of FIG. 10, all the divided images to which each plasma display device 1 is assigned are displayed regardless of the joint of the adjacent plasma display devices 1. As a result, the image is extended at the joint portion of the adjacent plasma display devices 1, but the display image is not defective.

  It can be considered that the joint setting is turned on only when a multi-screen is configured. Therefore, when joint setting is turned on in step S7, the setting in step S5 is automatically set to the multi-screen. You can configure it.

  Subsequently, image quality adjustment such as brightness, contrast, hue, color density, edge enhancement of the display image is performed (S8 in FIG. 9). At this time, when three plasma display devices 1 are arranged side by side to form a multi-screen, the three plasma display devices 1 are adjusted so that the image quality of the display images is aligned with each other.

  Subsequently, fine adjustment is performed on the display position and display size of the display image (S9 in FIG. 9), and the series of processing ends. At this time, when three plasma display devices 1 are arranged to form a multi-screen, the three plasma display devices are adjusted so that the positions of the display images are aligned with each other. In addition, each setting in step S8 and step S9 uses the remote controller similarly to step S1, for example, the setting screen which adjusts the image quality of a display image from the menu screen which performs various settings of the plasma display apparatus 1, or a display image This can be done by opening a setting screen for adjusting the position and size.

  In addition, each setting performed using the remote controller described above is realized, for example, by operating a program written to perform these processes on a microcomputer (not shown) built in the plasma display device 1. can do.

  The configuration for performing each setting using the remote controller described above is merely an example, and is not necessarily limited to this configuration. For example, the configuration is performed using a switch or the like provided in the plasma display device 1. Also good.

  Each setting performed in each step described above is stored in a storage device (for example, a semiconductor storage element or the like, not shown) included in the microcomputer described above, and the power supply to the next plasma display device 1 is stored. It is possible to save the trouble of repeating the series of settings described above by reading the stored contents and automatically resetting them when they are turned on.

  Although not shown here, the rotational speed of a fan (not shown) for radiating heat inside the casing of the plasma display device 1 is controlled when the vertical installation is set in step S1. It can also be configured as follows. The convection generated in the casing of the plasma display device 1 due to the heat generated by driving the panel 10 changes depending on whether the plasma display device 1 is placed vertically or horizontally. Changes. However, the effect of heat dissipation can be enhanced by controlling the rotational speed of the fan according to the installation direction.

  FIG. 11 is a circuit block diagram showing an example of the internal configuration of the image signal processing circuit 41 according to Embodiment 1 of the present invention.

  The image signal processing circuit 41 includes an APL detection unit 47, an installation direction selection unit 50, an image division unit 51, a display image selection unit 52, a maximum value detection unit 53, a single / multi setting unit 54, a luminance magnification setting unit 57, a display image. A cutout unit 60, an enlargement unit 61, a 90-degree rotation unit 62, a conversion unit 64, a selector 55, a selector 56, a selector 63, and a semiconductor memory element (not shown) for writing / reading image data are provided.

  The installation direction selection unit 50 opens an installation direction setting screen on a menu screen for performing various settings of the plasma display device 1, and the installer uses the remote controller, for example, to place the plasma display device 1 vertically or horizontally. You can set what to do. Based on the setting result by the installer, the selector 56 and the selector 63 are switched. In addition, if the initial setting in the installation direction selection unit 50 is set horizontally, this setting may be performed only when the plasma display device 1 is set vertically.

  The image division unit 51 divides the input image signal into three in the column direction (three divisions in the vertical direction in the drawing shown in the upper diagram of FIG. 7. (Referred to as “image”, “center image”, and “left image”).

  The display image selection unit 52 opens the display image selection screen in the above-described menu screen, and the installer uses, for example, a remote controller to change the display image to the “right image” or “center image”. Alternatively, it is possible to set whether to set the “left image”. Based on the setting result by the installer, one of the images divided by the image dividing unit 51 is selected. If the initial setting in the display image selection unit 52 is set to “center image”, this setting may be performed only when the display image is set to “right image” or “left image”.

  The APL detection unit 47 detects the APL of each image divided by the image division unit 51, the APL of the image selected by the display image selection unit 52, and the APL of the input image signal. The APL detection unit 47 may be configured to detect each APL by using one APL detection unit 47 in a time-sharing manner, or may be configured to provide as many APL detection units 47 as necessary.

  The maximum value detecting unit 53 detects the maximum value among the APLs detected from the images divided into three by the image dividing unit 51.

  The single / multi setting unit 54 opens a setting screen for setting whether to use a single screen or a multi-screen configuration on a menu screen for performing various settings of the plasma display device 1, and the installer uses the remote controller, for example, to set the plasma display device 1. It is possible to set whether to use a single unit or to configure a multi-screen by arranging three units. Then, the selector 55 is switched based on the setting result by the installer. If the initial setting in the single / multi setting unit 54 is set to single use, this setting may be performed only when three plasma display devices 1 are arranged to form a multi-screen.

  The selector 55 switches the output to the subsequent stage based on the setting result in the single / multi setting unit 54. Specifically, when the single use of the plasma display apparatus 1 is set in the single / multi setting unit 54, the APL detected from the image selected in the display image selection unit 52 is output, and the single / multi setting unit 54 When the multi-screen configuration is set at 54, the APL detected by the maximum value detection unit 53 is output.

  The selector 56 switches the output to the subsequent stage, that is, the luminance magnification setting unit 57, based on the setting result in the installation direction selection unit 50. Specifically, when the horizontal orientation of the plasma display device 1 is set in the installation direction selection unit 50, the APL detected from the input image signal is output, and the vertical installation of the plasma display device 1 is performed in the installation direction selection unit 50. Is set, APL output from the selector 55 is output.

  The luminance magnification setting unit 57 calculates the luminance magnification based on the APL output from the selector 56. In calculating the luminance magnification, for example, a conversion table (for example, the relationship shown in FIG. 4) in which the APL and the luminance magnification are associated with each other in advance is created, and the conversion table is referred to based on the input APL. Can be used.

  Here, when a multi-screen is configured using three vertically arranged plasma display devices 1, if the luminance magnification is set based on the brightness of the displayed image, the brightness of each plasma display device 1 depends on the image. The magnifications are different from each other, resulting in variations in brightness. Alternatively, when the luminance magnification is calculated in accordance with the APL of the input image signal and each plasma display device 1 is uniformly set to the luminance magnification, depending on the image (for example, a window pattern or the like, the APL is low, but a part of A bright image), and a plasma display apparatus 1 that is set to a high luminance magnification even though the display image is a sufficiently bright image occurs. However, in the present embodiment, with the above-described configuration, the luminance magnification of each plasma display device 1 is set according to the brightest image among the three divided images when the multi-screen is configured. Therefore, it is possible to prevent the occurrence of the problem as described above.

  Next, a circuit block that processes image data will be described. In addition, in order to show the processing of image data in an easy-to-understand manner, a description will be given here with a schematic drawing of a display image. FIG. 12 is a diagram schematically showing processing of image data in the first embodiment of the present invention.

  The display image cutout unit 60 cuts out the image selected by the display image selection unit 52, that is, one of the “right image”, “center image”, and “left image” from the image data based on the input image signal (see FIG. 12 shows a state in which the center image is cut out as an example).

  As shown in FIG. 12, the enlargement unit 61 converts the image data cut out by the display image cutout unit 60 into image data corresponding to the number of display pixels of the panel 10 (for example, an image of 1080 pixels in the row direction × 1920 pixels in the column direction). Data).

  As shown in FIG. 12, the 90-degree rotation unit 62 rearranges the image data arranged in the row direction in the column direction and the image data arranged in the column direction in the row direction (for example, 1920 pixels in the row direction). X image data of 1080 pixels in the column direction) and the image data is rotated 90 degrees. Thereby, the display image can be rotated 90 degrees.

  The converter 64 converts the input image signal into image data corresponding to the number of display pixels of the panel 10 (for example, image data of 1920 pixels in the row direction × 1080 pixels in the column direction).

  The selector 63 switches the output image data based on the setting result in the installation direction selection unit 50. Specifically, when the horizontal orientation of the plasma display device 1 is set in the installation direction selection unit 50, the image data output from the conversion unit 64 is output, and the vertical direction of the plasma display device 1 is output in the installation direction selection unit 50. When the setting is set, the APL output from the 90-degree rotating unit 62 is output.

  Even when the plasma display device 1 is used in a vertical position, when displaying a vertically dedicated image, it is not necessary to cut out, enlarge, and rotate the display image, so the installation direction selection unit 50 Preferably, the selector 56 is configured to output the APL detected from the input image signal, and the selector 63 is configured to output the image data output from the conversion unit 64.

  Each setting relating to the above-described image cropping, installation direction, single use / multi-screen, etc. is stored in a storage device provided in the above-described microcomputer (not shown), and the next time the plasma display device 1 is turned on. It is desirable that the stored contents are read and automatically set.

  Each process in the display image cutout unit 60, the enlargement unit 61, and the 90-degree rotation unit 62 is performed using a semiconductor memory element (not shown) generally called a RAM, which can arbitrarily write / read data by address control. (Hereinafter, RAM used for processing image signals is abbreviated as “image memory”). Next, control of the image memory at the time of image data cutout, enlargement, and 90 ° rotation will be described.

  FIG. 13 is a schematic diagram showing an image signal in one frame period and a write range to the image memory in Embodiment 1 of the present invention.

  As shown in FIG. 13, in this embodiment, the number of pixels in one horizontal synchronization period of an input image signal is H_TOTAL, and the number of horizontal synchronization periods in one vertical synchronization period (hereinafter referred to as “number of lines”) is V_TOTAL. The number of pixels A in one horizontal synchronization period and the number of lines in one vertical synchronization period to be written in the image memory based on the effective display area of the image signal (the area where valid image information exists. B is determined.

  FIG. 14 is a diagram schematically showing writing of image data to the image memory in the effective display area in the first embodiment of the present invention.

  As described above, in this embodiment, since the number of pixels in one horizontal synchronization period of the effective display area is A and the number of lines in the vertical synchronization period is B, A in the row direction (horizontal direction in the drawing). Image data arranged in an A × B matrix of B, ie, (1, 1) to (A, B) in the column direction (vertical direction in the drawing) is written in the image memory.

  Next, an operation for dividing the image data based on the input image signal into three and cutting out the image selected by the display image selection unit 52, that is, the “right image”, the “center image”, or the “left image” will be described. To do.

  FIG. 15 is a diagram schematically showing writing of image data cut out into three parts in the image memory according to Embodiment 1 of the present invention. Here, as an example, a state where the “center image” is cut out is shown.

  For example, when clipping of “center image” is selected in the display image selection unit 52, 1 × A × B image data written in the image memory from (1, 1) to (A, B) is 1 A / 3 pieces of image data from (A / 3 + 1,1) to (2 × A / 3,1) are read out as image data on the line, and are read into another area of the image memory or another image memory. Written. Subsequently, A / 3 pieces of image data from (A / 3 + 1, 2) to (2 × A / 3, 2) as the image data of the second row are similarly converted to (A / 3 + 1, B) of the B row. ) To (2 × A / 3, B) are sequentially read out and written to another area of the image memory or another image memory. In this way, the image data corresponding to the “center image” is cut out from the image data based on the input image signal (region indicated by hatching in the drawing). Further, when “right image” or “left image” is selected in the display image selection unit 52, image data corresponding to “right image” or “left image” is cut out by the same operation.

  Next, an operation for enlarging the cut-out image data to image data corresponding to the number of display pixels of the panel 10 will be described.

  FIG. 16 is a diagram schematically showing the enlargement of the cut-out image data in the first embodiment of the present invention.

  In the present embodiment, as shown in FIG. 16, the cut out image data (here, A / 3 pixel × B pixel) is enlarged in accordance with the number of pixels of panel 10 (here, n pixel × m pixel). . Therefore, n × 3 / A magnification is performed in the row direction and m / B magnification is performed in the column direction.

  FIG. 17 is a diagram schematically showing the enlargement in the row direction of the clipped image data in the first embodiment of the present invention.

  As shown in FIG. 17, when the cut out image data is enlarged in the row direction in accordance with the number of pixels of the panel 10, the image data read from the image memory may be multiplied by n × 3 / A times. Is repeatedly read a predetermined number of times (for example, 3 to 4 times), and an optimum interpolation filter (for example, LPF: Low Pass Filter or the like) according to the enlargement ratio is applied. Thus, the change between adjacent image data can be smoothed, and the read A / 3 image data can be expanded to n image data.

  FIG. 18 is a diagram schematically showing the expansion in the column direction of the cut-out image data in the first embodiment of the present invention.

  As shown in FIG. 18, when the cut out image data is enlarged in the column direction in accordance with the number of pixels of the panel 10, the number of lines of the image data read from the image memory may be increased by m / B times. Data is repeatedly read a predetermined number of times (for example, 3 to 4 times) in line units, and an optimal vertical interpolation filter (for example, LPF) according to the enlargement ratio is applied. In this way, the change between the image data adjacent in the column direction can be smoothed, and the read B-row image data can be expanded to m-row image data.

  FIG. 19 is a diagram schematically showing writing of the enlarged image data to the image memory in the first embodiment of the present invention.

  As shown in FIG. 18, the A / 3 × B image data cut out from the A × B image data is enlarged in accordance with the number of pixels of the panel 10, and from (1, 1) to (n, m). N × m pieces of image data up to and written to the image memory.

  Next, an operation for rotating the image data enlarged in accordance with the number of pixels of the panel 10 by 90 degrees will be described.

  FIG. 20 schematically shows a 90-degree rotation of the enlarged image data according to the first embodiment of the present invention.

  In the present embodiment, as shown in FIG. 20, image data (here, n pixels × m pixels) enlarged in accordance with the number of pixels of panel 10, and image data arranged in the row direction are arranged in the column direction. The image data arranged in the column direction is rearranged in the row direction, and the image data is rotated by 90 degrees.

  FIG. 21 is a diagram schematically showing writing of the enlarged image data to the image memory in the first embodiment of the present invention, and FIG. 22 is an image memory of the enlarged image data in the first embodiment of the present invention. FIG. 23 is a diagram schematically showing image data rotated by 90 degrees in the first embodiment of the present invention.

  In this embodiment, as shown in FIG. 21, image data (here, n pixels × m pixels) enlarged in accordance with the number of pixels of panel 10 is converted from (1, 1) to (n, From 1) to (1, m) to (n, m) in the m-th row, data are sequentially written in the image memory as indicated by arrows in the drawing. Specifically, after sequentially writing the image data from the first column (1, 1) of the first row to the image data of the last column (n, 1), the image data of the second row is subsequently written in the same order. After that, the image data from the third line to the m-th line are sequentially written in the same order.

  Subsequently, in the present embodiment, as shown in FIG. 22, the image data written in the image memory is changed from (1, m) to (1,1) in the first column to (n, m) in the nth column. ) To (n, 1) are sequentially read from the image memory as indicated by arrows in the drawing. Specifically, after sequentially reading from the image data of the last row (1, m) of the first column to the image data of the first row (1, 1), the image data of the second column is subsequently changed in the same order, That is, reading is performed from the last row to the first row, and thereafter the image data from the third column to the n-th column are sequentially read in the same order.

  In this way, the image data of m rows and n columns expanded in accordance with the number of pixels of the panel 10 is converted into image data of n rows and m columns as shown in FIG. 23, thereby rotating the display image by 90 degrees. Can do.

  In this embodiment, when the joint setting is turned on in the multi-screen, the non-display area of the image is set by limiting the writing range to the image memory, and the image corresponding to the joint of the adjacent plasma display devices 1 is set. Is not displayed.

  FIG. 24 is a diagram schematically showing a writing range of image data to the image memory when joint setting is turned on in the first embodiment of the present invention. Here, the range to be written to the image memory is indicated by oblique lines, and the area not to be written to the image memory is indicated by white.

  In the present embodiment, when the joint setting is turned on, an area that is not written in the image memory is not taken with a uniform width from the boundary line of the three divided images, as shown in FIG. ”And“ center image ”at a ratio of 2: 1, and at the boundary between“ center image ”and“ right image ”at a ratio of 1: 2.

  If an area that is not written to the image memory is set with a uniform width from the boundary line of each of the three divided images and a non-display area of the image is set, for example, a predetermined width from the boundary line when dividing the image is set. When the image data amount in the non-display area of the set image is Q, the image data amount in the non-display area in the “left image” and the “right image” is Q, whereas the non-display area in the “center image”. The amount of image data in the display area is 2Q, and the amount of image data to be displayed is reduced accordingly. In addition, if the position of the border is set with the difference in the amount of image data in the non-display area set in advance, the “left image”, “right image”, and “center image” are displayed when the joint setting is turned off. A difference occurs in the amount of image data. Alternatively, in order to equalize the amount of image data to be displayed, the position of the boundary line must be moved when the joint setting is turned on and off.

  However, in the present embodiment, as shown in FIG. 24, the ratio between the “left image” and the “center image” is 2: 1, and at the boundary between the “center image” and the “right image”. Since the non-display area of the image is set by providing an area that is not written in the image memory at a ratio of 1: 2, the position of the boundary line when the image is divided into three parts is moved without changing the joint setting. Regardless of the setting ON / OFF, it is possible to make the writing range (width in the horizontal direction in the drawing) equal to each other for each of “center image”, “right image”, and “left image”. Become. That is, when three plasma display devices are arranged to form a multi-screen and the joint setting is turned on, the leftmost plasma display device, the rightmost plasma display device, and the central plasma display device write to the image memory. The writing range of image data can be made equal to each other, and the image data amounts of images to be displayed can be made equal among the plasma display devices constituting the multi-screen.

  As described above, in the present embodiment, a normal image signal is cut out by dividing it into three parts, and the cut out image data is enlarged according to the number of pixels of the panel 10 and rotated by 90 degrees. When the image is used in a vertical position, it is possible to use not only a dedicated image having an aspect ratio of portrait but also a normal landscape image. Furthermore, since setting such as setting of the installation direction, selection of a display image, and ON / OFF of joint setting can be performed using a remote controller, each setting when the plasma display device 1 is placed vertically can be easily performed. . Further, a multi-screen can be easily configured by arranging three vertically arranged plasma display devices 1, and the luminance magnification of each plasma display device 1 is set to the luminance magnification in the plasma display device 1 having the brightest display image. Therefore, variations in the brightness of the screen can be prevented.

  In the present embodiment, the example in which the image dividing unit 51 divides the input image signal into three in the column direction and the three plasma display devices form a multi-screen of three screens has been described. Thus, in the configuration in which the image is divided into three, one plasma display device in which the “center image”, which is located in the center portion of the image and appears to have a relatively high frequency of displaying the viewer's gaze portion, is placed vertically. In addition, when the multi-screen configuration is used, there is an advantage that the joint between the plasma display devices and the loss due to the joint do not occur in the central portion of the screen. However, the present invention is not limited to this configuration, and one screen may be further divided into more regions to configure a larger multi-screen. For example, it is possible to divide one screen into N × M regions, which are divided into N in the column direction and M in the row direction, and configure an N × M multi-screen using N × M plasma display devices. it can. In this case, since the number of pixels in each region is A / N pixels in the row direction and B / M pixels in the column direction, the divided image data is n × N / in the row direction. The image data is multiplied by A, multiplied by m × M / B in the column direction, and expanded to image data of n pixels in the row direction and m pixels in the column direction.

  FIG. 25 is a diagram showing another example of the multi-screen configuration according to Embodiment 1 of the present invention. For example, as shown in the upper part of FIG. 25, the input image signal is divided into 12 parts, and the divided images are displayed on 12 plasma display devices as shown in the lower part of FIG. Can also be configured. Even with such a configuration, a multi-screen can be configured with the aspect ratio maintained at a value close to 16: 9, as in the case of the above-described three divisions. In this case, since one screen is divided into six in the column direction and divided into two in the row direction, the number of pixels in each region is A / 6 pixels in the row direction and B / in the column direction. 2 pixels. Therefore, after writing this image data into the image memory, each image data is repeatedly read from the image memory a predetermined number of times so as to be n × 6 / A times in the row direction and m × 2 / B times in the column direction. By applying an interpolation filter to the read image data, the image data is enlarged to n pixels in the row direction and m pixels in the column direction. Furthermore, the display image can be rotated 90 degrees by rearranging the image data arranged in the row direction in the column direction and the image data arranged in the column direction in the row direction, respectively. Can be displayed.

  In this embodiment, as shown in FIG. 22, the image data written in the image memory is changed from the image data of the last row (1, m) of the first column to the first row (1, 1). After sequentially reading up to the image data, the image data in the second column is subsequently read out in the same order, that is, from the last row to the first row, and thereafter the image data from the third column to the nth column in the same order. The configuration for reading sequentially has been described. As a result, as shown in FIG. 23, the image data can be rotated 90 degrees so that the left side (in the drawing) becomes the upper side (in the drawing). In this case, when the plasma display device 1 is installed, as shown in FIG. 12, the panel 10 is vertically placed so that the left end (in the drawing) is on the lower side (in the drawing). Becomes normal.

  However, by changing the reading order of the image data written in the image memory, when the plasma display device 1 is placed vertically so that the right end (in the drawing) of the panel 10 is in the lower side (in the drawing), It is also possible to rotate the image data by 90 degrees so that the vertical direction is normal. FIG. 26 is a diagram schematically showing another example of reading image data from the image memory according to the first embodiment of the present invention, and FIG. 27 is rotated by 90 degrees according to the first embodiment of the present invention. It is a figure which shows the other example of image data roughly. For example, as shown in FIG. 26, after sequentially reading from the image data of the first row (n, 1) of the nth column to the image data of the last row (n, m), the (n-1) th column. Are read in the same order, that is, from the first row to the last row, and thereafter the image data from the (n-2) th column to the first column are sequentially read in the same order. In this way, as shown in FIG. 27, the image data can be rotated 90 degrees so that the right side (in the drawing) becomes the upper side (in the drawing). In this case, when the plasma display device 1 is installed, the vertical orientation of the image becomes normal (not shown) by placing it vertically so that the right end of the panel 10 is on the lower side.

  In the present embodiment, as shown in FIG. 24, when the joint setting is turned on, the “center image” and the “center image” are “2: 1” at the boundary between the “left image” and the “center image”. The configuration has been described in which an area not written in the image memory is provided at a ratio of 1: 2 at the boundary with the “right image”. However, instead of providing an area that is not written to the image memory, when all image data of the selected image area is once written to the image memory and the image data is read from the image memory, this corresponds to the area that is not written to the image memory. The same effect can be obtained by not reading the area. In addition, when the joint setting is turned on, the configuration relating to the region that is not written to the image memory or the region that is not read from the image memory is not limited to the configuration in which one screen is divided into three, and one screen is divided into three or more regions. This is effective in the configuration of dividing into two.

(Embodiment 2)
In recent years, the amount of signals that must be processed per unit time has increased dramatically as the resolution of images has further increased. Therefore, a very high frequency clock signal, such as several hundred MHz, for example, for processing an image signal (a rectangular waveform signal used to synchronize the operation of each processing circuit when performing signal processing digitally) Has to be used. However, when the frequency of the clock signal increases, problems such as heat generated during signal processing and increased power consumption occur. Therefore, the circuit should be configured so that signal processing can be performed with a clock signal having the lowest possible frequency. Is desirable.

  Therefore, in the second embodiment, a configuration will be described in which when image data is rotated 90 degrees, image data is processed using a plurality of image memories and the frequency of a clock signal used for the processing is reduced.

  28, 29, and 30 are schematic diagrams showing the operation of the image memory when rotating the image data by 90 degrees according to the second embodiment of the present invention.

  In FIG. 28, FIG. 29, and FIG. 30, the odd-numbered image data is shaded for easy understanding of the image data processing. In this embodiment, a configuration using two image memories, that is, a first image memory and a second image memory will be described. In FIG. 28, both the first image memory and the second image memory are used. Only the region in the first row is shown. Further, the A / 3 × B image data cut out from the A × B image data is converted into n × m image data from (1, 1) to (n, m) according to the number of pixels of the panel 10. Since a series of processes until the enlargement is the same as the series of processes shown in FIG. 19 in the first embodiment, description thereof is omitted here. In this embodiment, the frequency of a basic clock signal used for processing image data is represented as “CK1”. In the following description, the frequency is set lower than that of the basic clock signal (here, about 1/2 of CK1), and the frequency of the clock signal used for controlling the image memory for 90 ° rotation is set to “ CK2 ".

  In this embodiment mode, the first image memory and the second image memory that perform writing and reading with a clock signal having a relatively large capacity but a low frequency, and temporary data at the time of writing to or reading from the image memory A configuration will be described in which image data is rotated 90 degrees using a buffer memory that can be used for storage and can be written and read with a clock signal having a high frequency but has a relatively small capacity. Specifically, the first image memory and the second image memory perform writing / reading with a clock signal having the frequency CK2, and have at least a half capacity of the image data. The buffer memory performs writing / reading with a clock signal having a frequency CK and has a capacity of at least one row of image data (n pixels), and here, two of them are used.

  First, among the image data expanded in m rows and n columns from (1, 1) to (n, m) in accordance with the number of pixels of the panel 10, (1, 1) to (n, 1) in the first row. ) Is written to the first buffer memory. Subsequently, the image data from (1, 2) to (n, 2) on the second line is written into the second buffer memory. In these processes, a clock signal having a frequency CK is used.

  Next, the image data from (1, 1) to (n, 1) written in the first buffer memory is read and written in the first image memory. At the same time, the image data from (1, 2) to (n, 2) written in the second buffer memory is read out and written in the second image memory. Since these processes use a clock signal having a frequency of CK2, the image data from (1, 1) to (n, 1) written in the first buffer memory is stored in the first image memory. The time until writing (hereinafter, the length of this time is abbreviated as “T”) is the time until image data from (1, 1) to (n, 1) is written to the first buffer memory. It takes about twice as long as, i.e., about 2T.

  However, the operation of writing the image data from (1, 1) to (n, 1) written in the first buffer memory to the first image memory and the data written in the second buffer memory (1, 2 ) To (n, 2) are simultaneously performed with the operation of writing the image data from (1, 1) to (n, 2) to the first image memory and The operation of writing to each of the second image memories can be completed in substantially a time of about 2T.

  On the other hand, after the image data from (1, 1) to (n, 1) is written to the first buffer memory, the image data from (1, 2) to (n, 2) is written to the second buffer memory. Since the time until writing is also about 2T, a certain delay necessary for a series of processing occurs. However, without increasing the delay, the clock signal of frequency CK2 can be used to change from (1, 1) to (n, 2 ) Can be written in the first image memory and the second image memory.

  The above operations are sequentially performed, and the image data up to the m-th row is written into the first image memory and the second image memory. As a result, as shown in FIG. 29, the odd-numbered image data is written in the first image memory, and the even-numbered image data is written in the second image memory.

  Next, as indicated by an arrow in FIG. 29, the image data written in the first image memory is changed from the image data of the last row (1, m−1) in the first column to the first row (1, 1). Are sequentially read out. At substantially the same time, the image data written in the second image memory is sequentially read from the image data of the last row (1, m) in the first column to the image data of the first row (1, 2). These processes are performed using a clock signal having a frequency of CK2.

  Then, as shown in FIG. 29, the image data read from the first image memory and the image data read from the second image memory can be switched, for example, by a clock signal having a frequency CK. Using a selector etc. At this time, adjustment is performed so that the image data read from the second image memory is first output from the selector.

  These processes are sequentially performed in the same order from the second column to the n-th column as shown in FIG. Thereby, the image data of m rows and n columns can be converted into the image data of n rows and m columns similar to that shown in FIG. 23, and the display image can be rotated by 90 degrees.

  As a specific example, for example, in the present embodiment, when processing a high-definition image signal called 1080i, a clock signal having a frequency CK of about 300 MHz is used as a basic clock signal. This converts a 74.25 MHz digital signal into a 148.5 MHz digital signal by so-called I / P conversion (converting an interlaced signal into a progressive signal), and processes the 148.5 MHz digital signal. For this reason, the frequency of the basic clock signal is doubled to 148.5 MHz. In this embodiment, with the above-described configuration, the first image memory and the second image memory are generated using a clock signal in which the frequency CK2 is set to about 162 MHz that is about 1/2 of the frequency CK. Writing / reading is performed.

  In the present embodiment, the configuration in which the buffer memory is used when writing to the first image memory and the second image memory has been described. However, the buffer memory is used when reading from the first image memory and the second image memory. It can also be set as the structure using.

  FIGS. 31 and 32 are schematic diagrams showing another example of the operation of the image memory when rotating the image data by 90 degrees according to the second embodiment of the present invention.

  In FIG. 31 and FIG. 32, the image data in the odd-numbered columns are shaded to show the state of the image data processing in an easily understandable manner.

  First, among the image data enlarged from (1, 1) to (n, m) in accordance with the number of pixels of the panel 10, the image data of the first column (1, 1) in the first row is used as the first image. Write to memory. Next, the image data of the second column (1, 2) in the first row is written into the second image memory. Subsequently, the image data of the third column (1, 3) in the first row is written to the first image memory, and then the image data of the fourth column (1, 4) in the first row is written to the second image. Write to memory. In this way, the odd-numbered column image data is written into the first image memory, and the even-numbered column image data is written into the second image memory.

  At this time, a clock signal having a frequency of CK2 is used for this processing. Therefore, the time required to write one image data to the image memory corresponds to the processing time of about 2 clocks of the clock of the frequency CK, that is, the processing time of about 2 pixels of the original image data. Since the image data and the even-numbered image data are alternately written in the first image memory and the second image memory, a certain delay necessary for a series of processing occurs, but the delay is increased. Instead, the image data can be written into the first image memory and the second image memory with the clock signal having the frequency CK2.

  Next, as indicated by the arrows in FIG. 32, the image data written in the first image memory is changed from the image data of the last row (1, m) in the first column to the image of the first row (1, 1). Data is read sequentially and written to the first buffer memory. At almost the same time, the image data written in the second image memory is sequentially read from the image data of the last row (2, m) in the first column to the image data of the first row (2, 1), and the second Write to buffer memory. At this time, a clock signal having a frequency of CK2 is used for this processing.

  Next, the image data written in the first buffer memory is sequentially read out, and after the reading is completed, the image data written in the second buffer memory is successively read out sequentially. At this time, a clock signal having a frequency of CK is used for this processing.

  Here, the time taken to sequentially read the image data written in the image memory and write to the buffer memory, that is, until the image data for one column is written to the buffer memory using the clock signal with the frequency set to CK2. Is 2T ′.

  At this time, the image data written in the first image memory is sequentially read and written in the first buffer memory, and the image data written in the second image memory is sequentially read and written in the second buffer memory. Thus, the operation of writing the image data for two columns in the buffer memory can be substantially completed in a time of 2T ′.

  On the other hand, the time for reading the image data written in the first buffer memory with the clock signal having the frequency CK is about half of 2T ′, that is, about T ′, so the image data written in the first buffer memory has the frequency CK. The time until the image data written in the second buffer memory is read out with the clock signal of frequency CK after being read out with the clock signal is about 2T ′, and a certain delay necessary for a series of processing occurs. The processing can proceed without increasing the value.

  As shown in FIG. 32, these processes are sequentially performed in the same order from the second column to the last column in both the first image memory and the second image memory. Thereby, the image data of m rows and n columns can be converted into the image data of n rows and m columns similar to that shown in FIG. 23, and the display image can be rotated by 90 degrees.

  As described above, according to the present embodiment, the use of the first image memory, the second image memory, and the buffer memory causes a certain delay necessary for a series of processes. The image data can be rotated by 90 degrees with the clock signal having the frequency CK2.

  Each operation described above may have a configuration in which the operations are performed in parallel within a range in which processing does not fail, for example, a configuration in which reading is performed simultaneously while writing to the buffer memory.

  In this embodiment, the configuration using two buffer memories having a capacity of at least one row of image data (n pixels) is described. However, at least two rows of image data (2 × n pixels) are used. It is also possible to use a buffer memory having the capacity of 2 and capable of reading or writing two data simultaneously. Further, if the writing / reading is controlled so that the data writing process does not overtake the data writing process, the capacity of the buffer memory is not necessarily limited to the capacity of two rows (2 × n pixels) of the image data. In addition, the same processing as described above can be performed with a buffer memory having a capacity smaller than two lines (2 × n pixels) of image data.

  In this embodiment, by using the same method as described above, it is possible to use three or more image memories and the same number of buffer memories as the image memory, and further reduce the frequency of the clock signal to be used. is there. However, it is desirable to use an even number of image memories from the viewpoint of ease of control.

  In the embodiment of the present invention, the configuration related to the cutout, enlargement, and 90-degree rotation of the selected image is not limited to the order shown in FIG. 12 of Embodiment 1, and the same effect can be obtained. The range may be implemented in any order.

  In the embodiment of the present invention, the configuration in which the RAM is used for the image memory has been described. However, for example, a semiconductor storage element such as a so-called FIFO (First In First Out) can be used. Further, the present invention is not limited to the semiconductor memory element, and a configuration using a magnetic memory device, an optical memory device, or the like that can be arbitrarily written / read may be used.

  Note that each operation described in the embodiment of the present invention may be performed using a dedicated LSI that performs each operation, and a program described to perform the same operation is executed by a microcomputer. May be. Alternatively, a dedicated LSI and a microcomputer may be used together.

  The specific numerical values shown in the embodiment of the present invention are set on the basis of a 50-inch panel having 1080 pairs of display electrodes used in the experiment, and only an example of the embodiment is shown. It's just a thing. The present invention is not limited to these numerical values, and is preferably set to an optimum value according to the characteristics of the panel, the specifications of the plasma display device, and the like. Each of these numerical values is allowed to vary within a range where the above-described effect can be obtained.

  The present invention configures a multi-screen without moving the position of the boundary line when dividing an image according to the joint setting when the multi-screen is constituted by a plurality of plasma display devices. Since the plasma display devices can be made equal in the amount of image data to be displayed, it is useful as a driving method for the plasma display device and the panel.

The disassembled perspective view which shows the structure of the panel in Embodiment 1 of this invention. Electrode arrangement of the panel Schematic waveform diagram showing a subfield configuration in the first embodiment of the present invention Schematic showing the relationship between APL and luminance magnification in Embodiment 1 of the present invention Drive voltage waveform diagram applied to each electrode of panel in embodiment 1 of the present invention Circuit block diagram of plasma display device according to Embodiment 1 of the present invention Schematic showing an example of image display when the plasma display device is placed vertically Schematic showing an example of image display when three vertically arranged plasma display devices in Embodiment 1 of the present invention are installed side by side The flowchart which shows an example of the operation | movement step of the plasma display apparatus in Embodiment 1 of this invention. Schematic for explaining ON / OFF of joint setting in Embodiment 1 of the present invention 1 is a circuit block diagram showing an example of an internal configuration of an image signal processing circuit according to Embodiment 1 of the present invention. The figure which shows schematically the process of the image data in Embodiment 1 of this invention Schematic diagram showing an image signal in one frame period and a write range to the image memory in Embodiment 1 of the present invention The figure which shows schematically the writing to the image memory of the image data in the effective display area in Embodiment 1 of this invention The figure which shows schematically the writing to the image memory of the image data cut out by dividing into 3 in Embodiment 1 of this invention The figure which shows schematically the expansion of the cut-out image data in Embodiment 1 of this invention The figure which shows schematically the expansion of the row direction of the cut-out image data in Embodiment 1 of this invention The figure which shows schematically the expansion in the column direction of the cut-out image data in Embodiment 1 of this invention The figure which shows schematically the writing to the image memory of the enlarged image data in Embodiment 1 of this invention The figure which shows roughly 90 degree rotation of the enlarged image data in Embodiment 1 of this invention The figure which shows schematically the writing to the image memory of the enlarged image data in Embodiment 1 of this invention The figure which shows schematically reading from the image memory of the enlarged image data in Embodiment 1 of this invention The figure which shows roughly the image data rotated 90 degree | times in Embodiment 1 of this invention The figure which shows schematically the writing range to the image memory when the joint setting in Embodiment 1 of this invention is turned on The figure which showed the other example of the multi-screen structure in Embodiment 1 of this invention The figure which shows schematically the other example of the reading from the image memory of Embodiment 1 of this invention The figure which shows schematically the other example of the image data rotated 90 degree | times in Embodiment 1 of this invention Schematic diagram showing the operation of the image memory when rotating the image data by 90 degrees in the second embodiment of the present invention Schematic diagram showing the operation of the image memory when rotating the image data by 90 degrees in the second embodiment of the present invention Schematic diagram showing the operation of the image memory when rotating the image data by 90 degrees in the second embodiment of the present invention Schematic which shows the other example of operation | movement of the image memory at the time of rotating the image data in Embodiment 2 of this invention 90 degree | times. Schematic which shows the other example of operation | movement of the image memory at the time of rotating the image data in Embodiment 2 of this invention 90 degree | times.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plasma display apparatus 10 Panel 21 Front plate (made of glass) 22 Scan electrode 23 Sustain electrode 24 Display electrode pair 25, 33 Dielectric layer 26 Protective layer 31 Back plate 32 Data electrode 34 Partition 35 Phosphor layer 41 Image signal processing circuit 42 data electrode drive circuit 43 scan electrode drive circuit 44 sustain electrode drive circuit 45 timing generation circuit 47 APL detection unit 50 installation direction selection unit 51 image division unit 52 display image selection unit 53 maximum value detection unit 54 single unit / multi setting unit 55, 56, 63 Selector 57 Luminance magnification setting unit 60 Display image cutout unit 61 Enlargement unit 62 90 degree rotation unit 64 Conversion unit

Claims (6)

A plasma display panel in which display pixels formed from a plurality of discharge cells emitting light in red, green, and blue colors are arranged in a matrix in a row direction and a column direction;
An image memory that converts input image signals into image data arranged in a matrix in the row direction and the column direction, divides the image data into at least three regions having boundaries in the column direction, and can arbitrarily write and read And an image signal processing unit that performs signal processing for displaying on the plasma display panel with respect to a preselected one of the at least three regions,
The image signal processor is
In a multi-screen configuration in which a plurality of plasma display devices are installed side by side and one image is divided into the at least three regions and enlargedly displayed on the plasma display device corresponding to each region
Based on a joint setting for setting whether or not to display an image of a portion corresponding to a joint of adjacent plasma display devices, a boundary between a leftmost region and a region adjacent to the leftmost region among the at least three regions; and A plasma display comprising a non-display area in which an image is not displayed at a ratio of 2: 1 at a boundary between a right end area of the at least three areas and an area adjacent to the right end area. apparatus. The image signal processor is
When performing the signal processing, at the boundary between the left end region and the region adjacent to the left end region and the boundary between the right end region and the region adjacent to the right end region, the ratio is 2: 1. The plasma display device according to claim 1, wherein the non-display area is provided by providing an area that is not written in the image memory. The image signal processor is
When performing the signal processing, at the boundary between the left end region and the region adjacent to the left end region and the boundary between the right end region and the region adjacent to the right end region, the ratio is 2: 1. 2. The plasma display device according to claim 1, wherein the non-display area is provided by providing an area from which image data is not read from the image memory. A plasma display panel in which display pixels formed from a plurality of discharge cells emitting light in red, green, and blue colors are arranged in a matrix in a row direction and a column direction;
An image memory that converts input image signals into image data arranged in a matrix in the row direction and the column direction, divides the image data into at least three regions having boundaries in the column direction, and can arbitrarily write and read And a method of driving a plasma display device comprising an image signal processing unit that performs signal processing for displaying on the plasma display panel for a preselected one of the at least three regions,
In a multi-screen configuration in which a plurality of plasma display devices are installed side by side, and one image is divided into the at least three regions and enlargedly displayed on the plasma display device corresponding to each region, the adjacent plasma display devices Based on the joint setting for setting whether or not to display an image of a portion corresponding to the joint, a boundary between the leftmost region of the at least three regions and a region adjacent to the leftmost region, and the at least three regions A method for driving a plasma display panel, characterized in that a non-display area that does not display an image is provided at a ratio of 2: 1 at a boundary between a right end area and an area adjacent to the right end area. When performing the signal processing in the image signal processing unit, at the boundary between the left end region and the region adjacent to the left end region, and the boundary between the right end region and the region adjacent to the right end region, 5. The method of driving a plasma display panel according to claim 4, wherein the non-display area is provided by providing an area not written to the image memory at a ratio of 2: 1. When performing the signal processing in the image signal processing unit, at the boundary between the left end region and the region adjacent to the left end region, and the boundary between the right end region and the region adjacent to the right end region, 5. The method of driving a plasma display panel according to claim 4, wherein the non-display area is provided by providing an area in which image data is not read from the image memory at a ratio of 2: 1.

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