JP4257097B2 - Plasma display device with imaging function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma display device with an imaging function, and more particularly to a plasma display device with an imaging function that can be used in a videophone system, a video conference system, and the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a videophone system or a video conference system, a camera is arranged in the vicinity of a display device, and a subject photographed by each camera is displayed on the other party's television.
[0003]
However, in this method, when a person gazes at the screen, the direction of the line of sight does not face the camera, so that the image of the subject out of line of sight is displayed on the other party's screen. In such a state, the line of sight does not coincide with each other (eye contact state), and a sense of incongruity is great in terms of communication.
[0004]
In order to solve this problem, in recent years, a device in which a small camera is installed on the screen of a display device has been proposed.
[0005]
In addition, a display device in which an image pickup device such as a CCD (charge coupled device) is incorporated has been proposed. In this method, an image sensor is arranged behind a flat CRT, a liquid crystal panel, or a PDP (plasma display panel), and a subject is imaged by this image sensor (see, for example, Patent Document 1).
[0006]
Specifically, when a flat CRT is used, a pinhole lacking a phosphor screen and a light-shielding conductive layer is provided on the screen of the CRT, and a subject is imaged through the pinhole.
[0007]
When a liquid crystal panel is used, a pinhole is provided at the center of one pixel of the liquid crystal panel or at a metal electrode, and a subject is imaged through the pinhole.
[0008]
Further, in the case of using the PDP, a pinhole is provided in the partition wall, and the subject is imaged through the pinhole.
[0009]
[Patent Document 1]
JP 2001-231019 (FIGS. 5 to 11).
[0010]
[Problems to be solved by the invention]
However, the method in which a small camera is installed on the screen of the display device has a problem that the screen is blocked by the camera.
[0011]
Further, in the method of providing a pinhole for imaging on a flat CRT screen, the pinhole always becomes a non-light emitting point, and there is a problem that the portion is lost when displaying a normal image such as a television.
[0012]
In the method of providing a pinhole for imaging at the center of one pixel of the liquid crystal panel or at the metal electrode, there is a problem that the diameter of the pinhole is small and light is not sufficiently transmitted.
[0013]
Similarly, in the method of providing an imaging pin hole in the PDP partition portion, the width of one partition wall is, for example, about 60 μm in a 40-inch PDP, so that the pin hole does not sufficiently transmit light. There is.
[0014]
The present invention has been made in consideration of such circumstances, and a PDP in which a partition wall is formed of a light-transmitting material is used, and an image sensor is disposed behind the PDP, thereby maintaining eye contact. And it aims at ensuring that the transmitted light amount of a panel can fully be ensured.
[0015]
[Means for Solving the Problems]
In the present invention, a large number of pixels having electrodes therein are formed, a part of each pixel is light transmissive, and light can be linearly transmitted from the display surface side to the back surface side through the light transmissive portion. A plasma display panel and a subject positioned on the display surface side of the plasma display panel are imaged through the plasma display panel, in a position where light transmitted from the display surface side to the back side of the plasma display panel can be received. With an image sensor capable of The light-transmitting part of the part of the pixel includes a partition, and the imaging element includes a camera having an imaging lens, and the light transmitted through the partition part of at least one pixel is received by the imaging lens. The camera is attached to the plasma display panel This is a plasma display device with an imaging function.
[0016]
According to the present invention, a part of each pixel uses a light transmissive plasma display panel, and the imaging element is arranged at a position where light transmitted from the display surface side to the back surface side of the plasma display panel can be received. Since the imaging element captures an image of the subject located on the display surface side of the plasma display panel through the plasma display panel, it is possible to secure a sufficient amount of light transmitted through the panel while maintaining sufficient eye contact. A good image can be displayed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, as the PDP, a large number of pixels having electrodes therein are formed, and some of the pixels are light transmissive, and light is linearly passed from the display surface side to the back surface side through the light transmissive portions. As long as it is transparent.
[0018]
The light-transmitting portion of each pixel may be any portion of the pixel. However, in order to minimize the influence on the display, it is desirable that the partition wall for partitioning the pixels be light-transmitting. .
[0019]
The PDP may have any structure such as an AC type, a DC type, a two-electrode structure, a three-electrode structure, a counter discharge type, and a surface discharge type. However, a plurality of PDPs may be provided between a pair of light-transmitting substrates. It is desirable to have a structure in which a light-transmitting barrier rib is formed and a phosphor layer is formed in a pixel region defined by the barrier rib.
[0020]
Examples of the pair of light-transmitting substrates include substrates made of glass, quartz, ceramics, etc., and substrates on which desired components such as electrodes, insulating films, dielectric layers, protective films are formed. .
[0021]
The partition wall only needs to be light transmissive. For example, the partition wall is formed with a groove in a light transmissive substrate, or a partition material such as a transparent low-melting glass is patterned on the light transmissive substrate. May be formed. However, in order to prevent the occurrence of “distortion” in the image of the subject that has passed through the partition wall of the PDP, the light needs to pass through the PDP linearly. From this point of view, the partition wall is preferably formed by cutting a light-transmitting substrate.
[0022]
For the formation of the partition wall by cutting the substrate, either a chemical method or a physical / mechanical method may be used. Chemical methods include wet etching and dry etching. Examples of the physical / mechanical method include a laser cutting method, a sand blasting method, and a cutting method using a cutting tool such as a fine end mill.
[0023]
This partition may be formed on any one of a pair of light transmissive substrates. That is, this partition may be formed on either the front side (display side) substrate or the back side substrate.
[0024]
Further, the shape of the partition wall is not particularly limited, and may be any shape such as a band shape, a lattice shape, a meander shape, and a honeycomb shape in plan view.
[0025]
The pair of light transmissive substrates includes a display surface side substrate and a back surface side substrate, and has a structure in which a louver that shields light generated from the phosphor layer of the PDP is provided on the back surface of the back surface side substrate. Also good.
[0026]
The pair of light transmissive substrates includes a display surface side substrate and a back side substrate, and a phosphor layer is formed on the back side substrate, and a PDP is formed between the phosphor layer and the back side substrate. The light-shielding layer which shields the light emitted from the phosphor layer may be provided.
[0027]
The pixel of PDP should just be divided by the partition etc. and has an electrode inside, for example.
[0028]
The electrodes need only be arranged inside the pixel, and various electrodes known in the art can be applied. Examples of the electrodes include transparent electrodes such as ITO and SnO2, and bus electrodes made of metals such as Ag, Au, Al, Cu, Cr, and laminates thereof (for example, a laminate structure of Cr / Cu / Cr). It is done. These electrodes can be formed with a desired thickness by using a printing method for Ag and Au, and by combining a film forming method such as a vapor deposition method and a sputtering method with an etching method for the others.
[0029]
The image sensor only needs to be disposed at a position where it can receive light transmitted from the display surface side to the back surface side of the PDP. Specifically, for example, it may be arranged behind the PDP. However, when light is guided by a lens, mirror, or optical fiber, it is not necessary to place it behind the PDP, and it may be placed at any position.
[0030]
The imaging element may be any element that can image a subject located on the display surface side of the PDP through the PDP. Various devices such as a camera having a lens, a CCD image sensor, a CMOS image sensor, and the like can be applied as the imaging element. However, for ease of handling, a camera having an imaging lens is used. Is desirable. As this camera, a camera using a CCD or a camera using a photomultiplier tube can be applied.
[0031]
When a camera having an imaging lens is used as the imaging device, the positional relationship between the PDP and the camera is such that the camera is attached to the PDP so that the light transmitted through the partition wall of at least one pixel is received by the imaging lens. It only has to be.
[0032]
The above configuration further includes a driver that applies a voltage for generating discharge to the electrodes in the PDP and a control circuit that controls the driver, and the control circuit has an imaging control unit that controls the imaging operation of the imaging device. In the imaging operation of the image sensor, the display of the PDP may be controlled so that the display of the pixels corresponding to the front surface of the image sensor is stopped.
[0033]
The apparatus further includes a driver that applies a voltage for generating discharge to the electrodes in the PDP, and a control circuit that controls the driver, and the control circuit includes an imaging control unit that controls the imaging operation of the imaging element. When displaying an image of a frame in gradation, one frame is divided into a plurality of subframes weighted for luminance, and in each subframe, an address discharge for selecting a pixel to emit light and a discharge of the selected pixel are maintained. An image may be displayed by performing display discharge, and the imaging operation of the imaging element may be controlled so that the imaging operation is performed during the address discharge period of the subframe.
[0034]
In this case, a configuration may be adopted in which the imaging operation of the imaging element is controlled by the control circuit so that the imaging operation is performed in the address discharge period in the subframe immediately after the subframe with the smallest weight in one frame.
[0035]
Alternatively, the control circuit aggregates a plurality of subframes having a small weight in one frame for displaying a PDP, and after the subframes are completed, imaging is performed during an address discharge period in the next subframe. It is good also as a structure which controls the imaging operation of an image pick-up element so that operation | movement may be performed.
[0036]
Further, the control circuit may be configured to hide the display of the PDP until afterglow of the phosphor layer of the PDP disappears before the imaging operation of the imaging device.
[0037]
Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. In addition, this invention is not limited by this, A various deformation | transformation is possible.
[0038]
FIG. 1 is an explanatory diagram showing a basic configuration of a plasma display device with an imaging function according to the present invention.
In the present invention, a CCD camera 1 having an imaging lens is attached behind the PDP 10, and the subject H is imaged by the CCD camera 1 via the PDP 10.
[0039]
The partition walls of the PDP 10 are light transmissive, and the CCD camera 1 is attached to the PDP 1 so that the light transmitted through the partition walls of at least one pixel is received by the imaging lens of the CCD camera 1.
[0040]
FIG. 2 is an explanatory view partially showing the configuration of the PDP of the plasma display device with an imaging function of the present invention. This example shows an AC type three-electrode surface discharge type PDP for color display.
[0041]
The PDP 10 includes a front panel assembly including a front substrate 11 and a rear panel assembly including a rear substrate 21. The front substrate 11 and the rear substrate 21 may be light transmissive, and a glass substrate, a quartz substrate, a ceramic substrate, or the like can be used. In this example, a transparent glass substrate is used.
[0042]
On the inner side surface of the substrate 11 on the front side, a plurality of pairs of display electrodes X and Y that are paired in the horizontal direction are formed at intervals of a non-discharge distance. Each of the display electrodes X and Y is made of a wide transparent electrode 12 such as ITO or SnO 2, for example, Ag, Au, Al, Cu, Cr, or a laminated body thereof (for example, a laminated structure of Cr / Cu / Cr). The bus electrode 13 is made of a narrow metal. The display electrodes X and Y are formed in a desired number, thickness, width and interval by using a printing method for Ag and Au, and by combining a film forming method such as a vapor deposition method and a sputtering method with an etching method for others. can do.
[0043]
A dielectric layer 17 is formed on the display electrodes X and Y so as to cover the display electrodes X and Y. The dielectric layer 17 is formed by applying a dielectric paste containing a low melting point glass or the like on the substrate 11 on the front side by a screen printing method and baking it.
[0044]
A protective film 18 is formed on the dielectric layer 17 to protect the dielectric layer 17 from damage caused by ion collision caused by discharge during display. The protective film 18 is made of, for example, MgO, CaO, SrO, BaO or the like.
[0045]
On the inner side surface of the substrate 21 on the back side, a groove portion 24 is formed in a direction intersecting the display electrodes X and Y in a plan view by a cutting method such as a sandblast method. In this sandblasting method, for example, the cutting portion can be sprayed in a state where a partition pattern cutting mask is provided on the substrate 21 on the back surface side, and the groove portion 24 can be formed by cutting the substrate 21 on the back surface side. The groove portion 24 is used as a discharge space, and the convex portion between the groove portion 24 and the groove portion 24 is used as a partition wall 29. Address electrodes A are formed on the bottom surface of each groove 24. The address electrode A generates an address discharge for selecting a light emitting cell at the intersection with the scanning display electrode. For example, Ag, Au, Al, Cu, Cr, and a laminate thereof (for example, Cr / Cu / Cr laminated structure) and the like. As with the display electrodes X and Y, the address electrode A also uses a printing method for Ag and Au, and the other by combining a film forming method such as a vapor deposition method and a sputtering method with an etching method to obtain a desired number and thickness. It can be formed with a width, width and spacing.
[0046]
In each groove 24, red (R), green (G), and blue (B) phosphor layers 28R, 28G, and 28B are formed for each color on the address electrodes A and on the side surfaces of the partition walls 29, respectively. . For the phosphor layers 28R, 28G, and 28B, a phosphor paste containing phosphor powder and a binder is applied in the groove portion 24 by screen printing or a method using a dispenser, and this is repeated for each color, followed by firing. It is formed by doing. The phosphor layers 28R, 28G, and 28B can be formed by a photolithography method using a sheet-like phosphor layer material (so-called green sheet) containing phosphor powder and a binder. In this case, a phosphor sheet of each color can be formed between the corresponding partition walls by applying a sheet of a desired color to the entire display area on the substrate, exposing and developing, and repeating this for each color. it can.
[0047]
In the PDP 10, the front panel assembly and the rear panel assembly described above are arranged so that the display electrodes X and Y and the address electrode A intersect with each other, the periphery is sealed, and the partition 29 is surrounded. It is produced by filling the groove 24 as a discharge space with a discharge gas. In this PDP 10, the groove 24 at the intersection of the display electrodes X and Y and the address electrode A is one cell region (unit light emitting region) which is the minimum unit of display. One pixel is composed of three adjacent R, G, and B cells.
[0048]
The display was first selected by using the display electrode group on the Y side as scan electrodes and sequentially applying a scan voltage to each display electrode Y and applying an address voltage to a desired address electrode A during that time. A light emitting cell is selected by generating an address discharge between the address electrode A and the display electrode Y. Usually, this period is called an address period. As a result of this discharge, wall charges are formed on the dielectric layer corresponding to the light emitting cell. Next, the display voltage (sustain voltage, or alternately) is alternately displayed between the Y-side display electrode group and the X-side display electrode group. A cell is caused to emit light by applying a discharge (also referred to as a sustain discharge) or a discharge (also referred to as a display discharge, a sustain discharge, or a sustain discharge) again in the cell in which the wall charges are accumulated. Usually, this period is called a display period. This cell emits light by exciting the phosphor with ultraviolet rays generated by display discharge and generating visible light of a desired color from the phosphor. In general, this method is called an address display separation driving method.
[0049]
In this PDP 10, the partition walls 29 are transparent. However, the ultraviolet light generated in each cell has a short wavelength, and therefore does not pass through the glass partition walls 29. On the other hand, since the fluorescence of the phosphor layers 28R, 28G, and 28B excited by the ultraviolet light passes through the partition walls 29, the mixed colors of R, G, and B are generated in an appropriate state.
[0050]
The display is performed by generating a display discharge between the display electrode X and the display electrode Y (hereinafter also referred to as the display electrode pair X and Y, or simply referred to as X and Y electrodes) as described above. The area between the X and Y electrodes where this discharge occurs is also called a light emitting slit, which is a light emitting area, but the area between the display electrode pair X, Y and the display electrode pair X, Y is also called a non-light emitting slit. Non-discharge region).
[0051]
Normally, when performing display, the PDP 10 holds the display electrodes X and Y in the horizontal direction and the address electrodes A in the vertical direction. In FIG. 1 and the subsequent drawings, the groove portion 24 and the partition wall 29 are shown. Therefore, a cross section parallel to the display electrodes X and Y is shown.
[0052]
FIG. 3 is a block diagram showing the configuration of the PDP drive circuit.
As shown in this figure, the drive circuit includes a Y scan driver circuit 31, an address driver circuit 32, a Y common driver circuit 33, an X common driver circuit 34, and a control circuit 35.
[0053]
The Y scan driver circuit 31 is a circuit that sequentially applies a scan voltage to the display electrodes Y1, Y2, Y3,. The address driver circuit 32 is a circuit for applying an address voltage to desired address electrodes A1, A2, A3,..., Am in the same address period.
[0054]
The Y common driver circuit 33 is a circuit that applies the display voltage to the Y-side display electrode group at the same time during the display period. In addition, the X common driver circuit 34 is a circuit that applies a display voltage to the display electrode group on the X side in the same display period.
[0055]
The control circuit 35 is a circuit that controls the Y scan driver circuit 31, the address driver circuit 32, the Y common driver circuit 33, and the X common driver circuit 34. The control circuit 35 includes a display data control unit 36 having a frame memory 36a, and a panel drive control unit 37 having a scan driver control unit 37a and a common driver control unit 37b.
[0056]
The panel drive control unit 37 receives the vertical synchronization signal VSYNC and the horizontal synchronization signal HSYNC. Then, a control signal is sent from the scan driver control unit 37 a to the Y scan driver circuit 31. Further, a control signal is sent from the common driver circuit 37 b to the Y common driver circuit 33 and the X common driver circuit 34. Further, a timing signal for controlling the Y scan driver circuit 31 is given to the display data control circuit 36.
[0057]
The display data control unit 36 receives the clock signal CLOCK and the data signal DATA. Then, the data signal for at least one frame is stored in the frame memory 36a. Further, in accordance with the timing of the Y scan driver circuit 31, data for one frame is sent to the address driver circuit 32 as an address data control signal for each line.
[0058]
A pulse power source 38 applies a pulse waveform voltage to the display electrodes X and Y and the address electrode A.
[0059]
FIG. 4 is an explanatory diagram showing the configuration of one frame for performing gradation display. This figure shows the structure of one field when one frame is composed of a plurality of fields such as an odd field and an even field.
[0060]
In the above-described driving of the PDP, usually, one frame is divided into a plurality of subframes (hereinafter referred to as SF) and displayed in order to display gradation. Then, for each SF, an address period for generating an address discharge for selecting a light emitting cell and a display period for continuously generating a display discharge in the light emitting cell to maintain the light emission of the cell are set. The number of display discharges is made different so that gradation is expressed by a combination of SFs.
[0061]
Specifically, as shown in FIG. 4B, a period of one frame is weighted, for example, 1T: 2T: 4T: 8T: 16T: 32T: 64T: 128T (T: reference time). Is divided into 8 SFs having the brightness ratio. The period of one frame is 1/60 = 16.7 ms when the frame frequency is 60 Hz.
[0062]
Then, as shown in FIG. 4A, in each SF period, a cell corresponding to the luminance of the SF to be executed is selected in the address period (non-display period) TA. Next, display discharge of the selected cell is performed in the display period TS. In the figure, for example, if there are 480 display lines and the address period is 1.5 ms, the scanning time for one line is about 3 μs (1.5 ms / 480 = 3.125 μs). This address period TA has the same length regardless of the weight of the SF.
[0063]
In this way, by selecting a cell corresponding to the luminance of the SF to be executed, 256 colors of R, G, and B are used. ^Three The gray scale display is performed. In this example, the order of the SF weights is set in ascending order. However, the order is not limited to this, and can be set in an arbitrary order.
[0064]
FIG. 5 is an explanatory diagram showing a state in which light transmitted through the partition wall is imaged. In this figure, the substrate on the front side of the PDP is omitted.
As described above, the partition walls 29 of the substrate 21 on the back side of the PDP are formed by cutting directly from a transparent glass substrate, and the partition walls 29 are transparent. Thereby, since the width of the groove 24 and the width of the partition wall 29 are in a ratio of about 8: 2, the entire screen of the PDP has a light transmittance of about 20%.
[0065]
The light L from the subject passes through the partition wall 29 of the substrate 21 on the back side, is converged by the imaging lens 1a of the CCD camera 1, and forms an image on the CCD array 1b as the imaging device.
[0066]
The distance between the imaging lens 1a of the CCD camera 1 and the substrate 21 on the back side is sufficiently smaller than the focal length of the imaging lens 1a. Therefore, the partition walls 29 of the substrate 21 on the back side are not imaged on the CCD array 1b. do not become.
[0067]
FIG. 6 is an explanatory view showing the state of light emitted from the phosphor layer.
Since the substrate 21 on the back side of the PDP is transparent, the light K from the phosphor layer formed in the groove 24 is also emitted behind the PDP. Therefore, the image on the CCD array 1b is covered with the light K from the phosphor layer. In order to shield the light K from the phosphor layer, there are methods of Embodiments 1 to 5 described below.
[0068]
Embodiment 1
FIG. 7 is an explanatory diagram showing an example in which a louver is attached to a PDP.
In this example, the louver 2 is provided to shield the light K emitted from the phosphor layer of the PDP.
[0069]
The louver 2 is formed by patterning an opaque metal such as chromium (Cr) or manganese (Mn) on the back side of the substrate 21 on the back side, or by directly applying a black pigment on the back side of the substrate 21 on the back side. . Patterning of metals such as Cr and Mn can be performed by combining a film forming method such as a vapor deposition method or a sputtering method with an etching method. The black pigment can be applied by applying a screen printing method or the like.
[0070]
The louver 2 may be provided on the entire surface of the substrate 21 on the back side, or may be provided only in front of the imaging lens 1 a of the CCD camera 1.
[0071]
Thus, in order to reduce the fog from the phosphor layer, the louver 2 for shielding light is provided on the back surface of the substrate 21 on the back surface side of the PDP. Thereby, the emitted light from the phosphor layer entering the imaging lens 1a can be shielded, and the fogging of the image can be suppressed.
[0072]
Embodiment 2
FIG. 8 is an explanatory view showing an example in which a phosphor layer light shielding layer of PDP is formed.
In this example, the light shielding layer 3 is provided to shield light emitted from the phosphor layers 28R, 28G, and 28B of the PDP 10.
[0073]
The light shielding layer 3 is formed by directly applying a black pigment to the back side of the phosphor layers 28R, 28G, 28B. The black pigment can be applied by applying a screen printing method or the like.
[0074]
The light shielding layer 3 may be made of a material that absorbs light for shielding light, but in order to improve the luminance in the front direction, it is better to use a completely reflective layer.
[0075]
Thus, in order to reduce the fog from the phosphor layer, the light shielding layer 3 is provided on the back side of the phosphor layer of the PDP. Thereby, the emitted light from the phosphor layer entering the CCD camera 1 can be shielded, and the fogging of the image can be suppressed.
[0076]
In the above, the method of physically shielding the emitted light from the phosphor layer in order to reduce the fog from the phosphor layer has been described, but in the following, the emitted light from the phosphor layer is controlled by the control circuit. How to eliminate the influence of.
[0077]
Embodiment 3
FIG. 9 is a block diagram showing a configuration of a driving circuit of a PDP in which a circuit for reducing the influence of radiated light from the phosphor layer is incorporated.
This circuit is basically the same as the circuit of FIG. Therefore, only different components will be described. In this circuit, a camera control unit 41 as an imaging control unit is provided in the control circuit 35. The camera control unit 41 sends a shutter trigger signal to the CCD camera 1 and sends control signals to the display data control unit 36 and the panel drive control unit 37.
[0078]
In addition, it receives imaging data from the CCD camera 1, processes the imaging data, and outputs it as data DATA.
[0079]
FIGS. 10A, 10B, and 10C are explanatory diagrams illustrating a control method that eliminates light emission before the lens of the camera. 10A shows a display example of the entire screen, FIG. 10B is an enlarged view of the black spot P, and FIG. 10C is a side view of the CCD camera 1 located at the black spot P portion.
[0080]
In this example, in order to eliminate the influence of the radiated light from the phosphor layer, during the imaging operation of the CCD camera 1, display of pixels located on the front side of the imaging lens 1 a of the CCD camera 1 is not performed. As described above, as a control for not displaying pixels, an address data control signal is not sent from the display data control unit 36 to pixels that are not displayed.
[0081]
When this control is performed, a portion corresponding to the imaging lens of the camera on the screen appears as a black spot P as shown in FIG. However, as shown in FIGS. 10B and 10C, even if this black point P exists, the size of the imaging lens 1a of the CCD camera 1 is several millimeters, so the size of the black point P is also several. It is small and is not worrisome from the whole screen.
[0082]
When the CCD camera 1 is not used, since all the pixels of the PDP are displayed, the black point P is not displayed.
[0083]
Embodiment 4
FIG. 11 is an explanatory diagram illustrating an example in which an imaging operation is performed during an address period.
The SF when displaying the PDP screen is divided into an address period TA and a display period TS as shown in FIG. Using this feature, the CCD camera performs imaging during the address period TA, which is a non-display period. In FIG. 11, the SF arrangement order is in descending order. For example, as described above, SFs with small weights are collected before the imaging operation, and the address period TA of SF8 with the smallest luminance weight among them is collected. ₁ The CCD camera is controlled so that the image pickup operation is performed during the period.
[0084]
In this imaging operation, when the camera control unit 41 receives a timing signal for generating a scan signal from the panel drive control unit 37, it detects that it is the address period TA, and the camera control unit 41 responds to the CCD camera 1 accordingly. In response, a shutter trigger signal is sent.
[0085]
In this way, if the CCD camera is imaged during the address period TA, the PDP does not emit light, and therefore the captured image is affected by the radiation from the phosphor layer when the CCD camera is imaged. There is no.
[0086]
In this case, as shown in FIG. 12, the afterglow time of the R, G, and B phosphor layers of the PDP may be long due to the characteristics of the phosphors. For this reason, even after the address period TA, afterglow in the immediately preceding display period may remain. In this case, the pixels on the front surface of the CCD camera 1 are not displayed before the imaging operation of the CCD camera 1 is performed for a time longer than the afterglow time of the phosphor.
[0087]
FIG. 13 is an explanatory diagram showing an example of the SF arrangement and the light emission intensity during the display period. Since the afterglow of the phosphor layer is proportional to the emission intensity within the afterglow time, the SF is arranged as follows.
That is, before the start of the imaging operation of the CCD camera, that is, before the image is captured, SFs with small weights are collected, and SFs with small weights, for example, SF5, SF6, and SF7 are set in a pause state (not displayed). Then, after the afterglow of SF4 disappears in the rest period of SF5, SF6, and SF7, the period t ₁ ~ T ₂ By taking an image with a CCD camera during this period, the influence of afterglow by the phosphor layer is eliminated. The number of SFs to be in the resting state may be appropriately set in consideration of the afterglow time of the R, G, B phosphor layers.
[0088]
Thus, before the start of the imaging operation of the CCD camera, the display of the PDP is not displayed for a time longer than the afterglow time of the phosphor. This non-display may be performed for all the pixels of the PDP or only for the pixels in front of the CCD camera.
[0089]
When a non-displayed SF is provided, that is, when the SF is controlled to be thinned out, the number of gradations when the subject is imaged is reduced. Since the range is as small as a few millimeters, it does not affect the overall display. When displaying a normal image, the display discharge is also performed for all the SFs on the pixels on the front surface of the CCD camera, so the number of gradations does not decrease.
[0090]
Embodiment 5
FIG. 14 is a graph showing the relationship between emission intensity and afterglow intensity.
In the PDP, there is a certain relationship between the light emission intensity of the pixel and the afterglow intensity. Therefore, in this example, the afterglow intensity is calculated from the emission intensity, and this afterglow intensity is subtracted from the captured image signal by image processing. Thereby, the influence of the afterglow by a fluorescent substance layer is removed.
[0091]
Ultraviolet light emission is t ₀ , The emission intensity at the time t of the pixel emitting with the emission intensity (luminance) y is F = (y, tt ₀ ).
[0092]
If the pixel numbers in front of the imaging lens of the CCD camera are i to j, the total amount of light due to the afterglow incident on the imaging lens 1a is
L (t) = ΣF (y _k , Tt ₀ )
Can be predicted. Using this L (t), the captured image is corrected. Specifically, t ₀ Y _k , L (t) is calculated based on the data, and the emission intensity at time t is obtained.
[0093]
When this method is used, in principle, the subject may be imaged at any timing without using the method of the first to fourth embodiments, but it can be freely combined with any of the first to fourth embodiments. May be used.
[0094]
FIG. 15 is an explanatory diagram showing an image processing circuit for removing afterglow of the phosphor layer from a captured image.
In this figure, 41a is a frame memory provided in the camera control unit 41, and 41b is a darkest point detection data expansion circuit provided in the camera control unit 41.
[0095]
When performing this process, the image captured by the CCD camera 1 is stored in the frame memory 41a, and the afterglow component of the phosphor layer is removed from the stored image by the darkest point detection data expansion circuit 41b. .
[0096]
FIG. 16A to FIG. 16D are explanatory diagrams showing display examples of emission intensity before and after removal of afterglow components and actual images.
The image including the afterglow component of the phosphor layer is in a state where the afterglow component of the phosphor layer is covered, as shown in FIG. 16A, and the emission intensity at this time is shown in FIG. As described above, the afterglow component of the phosphor layer is included. Therefore, the afterglow component of the phosphor layer is removed from this image as shown in FIG. As a result, a clear image as shown in FIG.
[0097]
As a method for evaluating the afterglow component, the afterglow component may be predicted from the light emission pattern of the pixel using a numerical model of the afterglow characteristics of the phosphor, and correction may be performed.
[0098]
In addition, as a method of predicting the afterglow component, the light amount (light emission intensity) at the end of the last light emission is actually measured, and the light amount is predicted by the attenuation rate up to the actual image capture time. May be.
[0099]
In this way, the PDP barrier ribs are directly cut from the glass substrate, so that the PDP barrier ribs are formed of light-transmitting glass, and a camera is attached to the back of the PDP, and light emission from the PDP phosphor layer By removing the influence of the above, it is possible to provide a plasma display device with an imaging function for a video phone or a video conference capable of eye contact.
[0100]
Plasma display devices are characterized by a large screen and high definition, and by using these systems, it is possible to obtain a real feeling as if they existed there.
[0101]
【The invention's effect】
According to the present invention, an image sensor is arranged behind a PDP that allows light to pass linearly, and a subject located on the display surface side of the PDP is imaged by the image sensor via the PDP. Can be obtained. Further, a sufficient amount of light transmitted through the panel can be ensured, and an image with good image quality can be displayed.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a basic configuration of a plasma display device with an imaging function according to the present invention.
FIG. 2 is an explanatory view partially showing a configuration of a PDP of a plasma display device with an imaging function of the present invention.
FIG. 3 is a block diagram showing a configuration of a PDP drive circuit in the embodiment.
FIG. 4 is an explanatory diagram showing a configuration of one frame for performing gradation display.
FIG. 5 is an explanatory diagram showing a state in which light transmitted through a partition wall in the embodiment forms an image.
FIG. 6 is an explanatory diagram showing a state of light emitted from the phosphor layer in the embodiment.
FIG. 7 is an explanatory diagram showing an example in which louvers are attached to the PDP in the embodiment.
FIG. 8 is an explanatory diagram showing an example in which a light shielding layer is formed on the phosphor layer of the PDP in the embodiment.
FIG. 9 is a block diagram showing a configuration of a driving circuit of a PDP incorporating a circuit for reducing the influence of light emitted from a phosphor layer in the embodiment.
FIG. 10 is an explanatory diagram showing a control method for eliminating light emission before the lens of the camera in the embodiment.
FIG. 11 is an explanatory diagram illustrating an example in which an imaging operation is performed during an address period in the embodiment.
FIG. 12 is a graph showing the afterglow time of light emission of the phosphor layer.
FIG. 13 is an explanatory diagram showing an example of the SF arrangement in the embodiment and the emission intensity during the display period.
FIG. 14 is a graph showing the relationship between emission intensity and afterglow intensity.
FIG. 15 is an explanatory diagram showing an image processing circuit for removing afterglow of a phosphor layer from a captured image in the embodiment.
FIG. 16 is an explanatory diagram showing a display example of emission intensity and an actual image before and after the removal of afterglow components.
[Explanation of symbols]
1 CCD camera
1a Imaging lens
1b CCD array
2 louvers
3 Shading layer
10 PDP
11 Front side board
12 Transparent electrode
13 bus electrode
17 Dielectric layer
18 Protective film
21 Back side substrate
24 groove
28R, 28G, 28B phosphor layer
29 Bulkhead
31 Y scan driver circuit
32 Address driver circuit
33 Y common driver circuit
34 X common driver circuit
35 Control circuit
36 Display data controller
36a frame memory
37 Panel drive controller
37a Scan driver controller
37b Common driver controller
38 Pulse power supply
41 Camera control unit
41a frame memory
41b Darkest point detection data expansion circuit
A Address electrode
L Light from subject
X, Y display electrode

Claims (9)

A plasma display panel in which a large number of pixels having electrodes therein are formed, a part of each pixel is light transmissive, and light can be transmitted linearly from the display surface side to the back surface side through the light transmissive portion. When,
An image sensor that is arranged at a position where light transmitted from the display surface side of the plasma display panel to the back surface side can be received and can image a subject located on the display surface side of the plasma display panel through the plasma display panel It equipped with a door,
The light-transmitting portion of a part of the pixel includes a partition, the imaging element includes a camera having an imaging lens, and the light transmitted through the partition portion of at least one pixel is received by the imaging lens. A plasma display device with an imaging function in which a camera is attached to a plasma display panel . The plasma display panel has a structure in which a plurality of light-transmitting barrier ribs are formed between a pair of light-transmitting substrates, and a phosphor layer is formed in a pixel region defined by the barrier ribs,
The plasma display device with an imaging function according to claim 1, wherein the partition wall is formed by cutting one of the pair of light-transmitting substrates. The pair of light transmissive substrates includes a display surface side substrate and a back surface side substrate, and a louver that shields light generated from a phosphor layer of the plasma display panel is provided on the back surface of the back surface side substrate. Item 3. A plasma display device with an imaging function according to Item 2 . The pair of light transmissive substrates includes a display surface side substrate and a back side substrate, a phosphor layer is formed on the back side substrate, and a plasma display panel is formed between the phosphor layer and the back side substrate. The plasma display device with an imaging function according to claim 2, wherein a light shielding layer for shielding light generated from the phosphor layer is provided. A driver for applying a voltage for generating discharge to the electrodes in the plasma display panel, and a control circuit for controlling the driver;
The control circuit has an imaging control unit that controls the imaging operation of the imaging device, and controls the display of the plasma display panel so that the display of the pixels corresponding to the front surface of the imaging device is stopped during the imaging operation of the imaging device. The plasma display device with an imaging function according to claim 1. A driver for applying a voltage for generating discharge to the electrodes in the plasma display panel, and a control circuit for controlling the driver;
The control circuit has an image pickup control unit that controls the image pickup operation of the image pickup element, and when displaying an image of one frame in gradation, the frame is divided into a plurality of subframes weighted to luminance, and each subframe is divided into An image is displayed so that an image is displayed by performing an address discharge for selecting a pixel to emit light and a display discharge for maintaining the discharge of the selected pixel so that an imaging operation is performed during the address discharge period of the subframe. The plasma display device with an imaging function according to claim 1, which controls an imaging operation. The plasma display with an imaging function according to claim 6 , wherein the control circuit controls the imaging operation of the imaging device so that the imaging operation is performed during an address discharge period in a subframe immediately after the subframe with the smallest weight in one frame. apparatus. The control circuit aggregates a plurality of subframes having a low weight in one frame for displaying the plasma display panel, and after those subframes are completed, the image is captured during the address discharge period in the next subframe. The plasma display device with an imaging function according to claim 6, wherein the imaging operation of the imaging device is controlled so that the operation is performed. The plasma display device with an imaging function according to claim 6 , wherein the control circuit hides the display of the plasma display panel until afterglow of the phosphor layer of the plasma display panel disappears before the imaging operation of the imaging device.

Images