Abstract:
A temperature of the plasma display panel is detected by a temperature sensor. An apparatus includes a display panel, a plate disposed adjacent to a rear surface of the panel, and a board disposed substantially parallel to the plate. A temperature sensor is formed on the board, and the temperature sensor is disposed between the plate and the board.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation application of prior U.S. patent application Ser. No. 10/849,875 filed May 21, 2004, which claims priority under 35 U.S.C. §119 to Korean Application No. P2003-33075 filed on May 23, 2003, whose entire disclosures are hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a plasma display panel, and more particularly, to an apparatus of driving a plasma display panel capable of accurately detecting a temperature of the plasma display panel for a stable driving of the plasma display panel. 
         [0004]    2. Description of the Related Art 
         [0005]    Recently, various flat panel devices have been developed that reduce weight and bulk, which are drawbacks of the cathode ray tube (CRT). Such flat panel display devices include a liquid crystal display (LCD) device, a field emission display (FED) device, a plasma display panel (PDP), an electro-luminescence display (ELD) device, and the like. 
         [0006]    The PDP of these flat panel display devices displays pictures by using a plasma discharge. The PDP has been used for high-resolution televisions, monitors and internal or external advertising display devices because it has a rapid response speed and is suitable for displaying a large-area picture. 
         [0007]    Referring to  FIGS. 1 and 2 , a related art PDP includes a panel  10 , a printed circuit board (PCB)  18  for driving the panel  10  and a heat-proof plate  20  attached to a rear surface of the panel  10 . 
         [0008]    The panel  10  includes: an upper substrate  10   a  having a plurality of scan electrodes and a plurality of sustain electrodes; and a lower substrate  10   b  having a plurality of address electrodes formed in a direction crossing the scan electrodes and the sustain electrodes, and a phosphorous material layer formed on an entire surface of the substrate. A phosphorous material generates a visible ray by a discharge between the scan electrodes and the sustain electrodes, and the address electrodes, and adjusts a transmittance of the visible ray to display a designated picture. 
         [0009]    The heat-proof plate  20  supports the panel  10  and serves to radiate a heat generated upon driving of the panel  10 . The heat-proof plate  20  is made of a metal material with a good thermal conductivity, for example, aluminum (Al), for malting a radiation well. 
         [0010]    The panel  10  requires a plurality of driver integrated circuits (ICs), connected to the scan electrodes and the address electrodes, for supplying a data signal and a scanning signal. The driver ICs include a scan driver IC  3  and a data driver IC 2 . Each of the driver panel  10  in response to a control signal supplied from the PCB  18 . To this end, the PCB  18  and the panel  10  are connected to each other by mean of a flexible printed circuit (FPC)  14 . If the driver ICs are packaged by way of a chip on film (COF) system, one side of the FPC  14  is connected to an IC chip  16  of the scan and the data drivers  3  and  2 , and other side of the FPC  14  is connected to pads  12  connected to driving electrodes of the panel  10 . 
         [0011]    A case  30  is installed to protect the PDP from an external impact when the PDP is produced. 
         [0012]    Such a PDP is driven by a time-divisional scheme in which one frame is divided into various sub-fields having a different emission frequency, so as to realize gray levels of a picture. Each sub-field is again divided into an initialization period for initializing the entire field, an address period for selecting a scan line and selecting the cell from the selected scan line and a sustain period for expressing gray levels depending on the discharge frequency. 
         [0013]    Herein, the initialization period is again divided into a set-up interval during which a rising ramp waveform is supplied and a set-down interval during which a falling ramp waveform is supplied. For instance, when it is intended to display a picture of 256 gray levels, a frame interval equal to 1/60 second (i.e. 16.67 msec) is divided into 8 sub-fields SF 1  to SF 8  as shown in  FIG. 2 . Each of the 8 sub-field SF 1  to SF 8  is divided into the initialization period, the address period and the sustain period as mentioned above. Herein, the initialization period and the address period of each sub-field are equal for each sub-field, whereas the sustain period and the number of sustain pulses assigned thereto are increased at a ratio of 2n (where n=0, 1, 2, 3, 4, 5, 6 and 7) at each sub-field. 
         [0014]      FIG. 4  shows a driving waveform of the PDP applied to two sub-fields. 
         [0015]    In  FIG. 4 , Y represents the scan electrode, Z represents the sustain electrode, and X represents the address electrode. 
         [0016]    Referring to  FIG. 4 , the PDP is divided into an initialization period for initializing the full field, an address period for selecting a cell, and a sustain period for sustaining a discharge of the selected cell for its driving. 
         [0017]    In the initialization period, a rising ramp waveform Ramp-up is simultaneously applied to all of the scan electrodes Y in a set-up interval. This rising ramp waveform Ramp-up causes a weak discharge within cells of the full field to generate wall charges within the cells. In the set-down interval, after the rising ramp waveform Ramp-up was supplied, a falling ramp waveform Ramp-down falling from a positive voltage lower than a peak voltage of the rising ramp waveform Ramp-up is simultaneously applied to the scan electrodes Y. The falling ramp waveform Ramp-down causes a weak erasure discharge within the cells, to thereby erase spurious charges of wall charges and space charges generated by the set-up discharge and uniformly leave wall charges required for the address discharge within the cells of the full field. 
         [0018]    In the address period, a negative scanning pulse Scan is sequentially applied to the scan electrodes Y, and, at the same time, a positive data pulse Data is applied to the address electrodes X. A voltage difference between the scanning pulse Scan and the data an address discharge within the cells to which the data pulse Data is supplied. Wall charges are formed within the cells selected by the address discharge. 
         [0019]    Meanwhile, a positive direct current voltage having a sustain voltage level Vs is applied to the sustain electrodes Z during the set-down interval and the address period. 
         [0020]    In the sustain period, a sustaining pulse Sus is alternately applied to the scan electrodes Y and the sustain electrodes Z. Then, a wall voltage within the cell selected by the address discharge is added to the sustain pulse Sus to thereby generate a sustain discharge taking a surface-discharge type between the scan electrode Y and the common sustain electrode Z whenever each sustain pulse Sus is applied. Finally, after the sustain discharge has been finished, an erasing ramp waveform Erase having a small pulse width is applied to the sustain electrode Z to thereby erase wall charges left within the cells. 
         [0021]    However, if the related art PDP is operated at a low temperature, then a brightness point erroneous fire occurs. In other words, as the result of an operation characteristic at a low-temperature, the PDP in accordance with the operation temperature causes the brightness point erroneous fire at a plurality of discharge cells. It has been supposed that such a brightness point erroneous fire occurs because a motion of particles becomes dull at the low temperature. 
         [0022]    More specifically, if a motion of particles becomes dull at a low temperature, then an erasure discharge caused by the erasing ramp waveform Erase may be not normally generated. Wall charges formed in the scan electrode Y and the sustain electrode Z are not Thereafter, in the set-up interval, a positive rising ramp waveform Ramp-up is applied to the scan electrode Y. At this time, since negative wall charges has been formed at the scan electrode Y, that is, since the polarity of a voltage applied to the scan electrode Y is contrary to that of wall charges formed in the scan electrode Y, a normal discharge is not generated in the set-up interval. Thus, a normal discharge is not generated in the set-down interval following the set-up interval. As described above, if the normal discharge does not occur in the initialization period, then wall charges excessively formed in the erasure period make an affect to the address period and the sustain period. In other words, a strong discharge entailing an undesired shape of brightness point is generated in the sustain period due to the wall charges formed excessively in the discharge cells. Thus, in order to prevent the brightness point erroneous fire at the low temperature, the PDP detects a peripheral temperature by a temperature sensor  17  installed in the PCB  18  as shown in  FIG. 2  to apply a driving waveform for a driver to suit with a temperature of the driver, to thereby make to display. 
         [0023]    However, since a voltage property and a waveform property of a module according to the peripheral surrounding are different, all of the driving properties of a panel can be adjusted in accordance with a temperature, but a reference surrounding temperature and an actual temperature of the panel have a lot of difference. That is, since the temperature sensor  17  is built in the PCB  18  and detects the temperature of the panel  10 , it is impossible to detect an accurate temperature and it is difficult to compensate an error caused by the temperature. 
       SUMMARY OF THE INVENTION 
       [0024]    Accordingly, it is an object of the present invention to provide an apparatus of driving a plasma display panel capable of accurately detecting a temperature of the plasma display panel for a stably driving of the plasma display panel. 
         [0025]    In order to achieve these and other objects of the invention, an apparatus of driving a plasma display panel according to an embodiment of the present invention includes: a display panel; a heat-proof plate attached on a rear surface of the panel; a heat carrying sheet, attached on a rear surface of the heat-proof plate, for carrying a temperature of the panel; and a temperature sensor, installed in a substrate, for detecting a temperature of the heat carrying sheet. 
         [0026]    The apparatus further includes; a polarity of protrusions, installed on the rear of the heat-proof plate, for fixing the heat-proof plate to the substrate; and a double-sided tape, attached on the rear of the heat-proof plate, for attaching the protrusions to the heat-proof plate. 
         [0027]    The apparatus further includes a molding product formed between the protrusions and the double-sided tape. 
         [0028]    In the apparatus, the molding product uniformly keeps a gap between the heat-proof plate and the substrate. 
         [0029]    In the apparatus, the heat carrying sheet is formed as an insulator and includes a resin, having a heat transfer coefficient more than approximately 1.5 W/mk. 
         [0030]    The apparatus further includes: a driving circuit part for driving the panel; and a controller for controlling the driving circuit part. 
         [0031]    In the apparatus, the controller supplies a control signal depending on the temperature of the panel detected from the substrate to the driving circuit part. 
         [0032]    In the apparatus, the driving circuit part supplies a driving waveform depending on the control signal supplied from the controller to the panel. 
         [0033]    The apparatus further includes a detection circuit, installed on the substrate, for converting an analog temperature signal of the display panel supplied by the temperature sensor into a digital temperature signal. 
         [0034]    The apparatus further includes: a plurality of holes, formed on the substrate, in which the protrusions are inserted, respectively; and a connector for supplying an output signal of the detection circuit to the controller. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0035]    These and other objects of the invention will be apparent from the following detailed description of the embodiment of the present invention with reference to the accompanying drawings, in which: 
           [0036]      FIG. 1  is a perspective view illustrating a related art plasma display panel; 
           [0037]      FIG. 2  is a sectional view illustrating a plasma display panel shown in  FIG. 1 ; 
           [0038]      FIG. 3  is a configuration representing a frame constitution of 8-bit default code for realizing 256 gray levels; 
           [0039]      FIG. 4  is a waveform diagram representing a driving method of a plasma 
           [0040]      FIG. 5  is a configuration of an apparatus of driving a plasma display panel according to an embodiment of the present invention; 
           [0041]      FIG. 6  is a configuration of the plasma display panel shown in  FIG. 5  rotated by 180°; 
           [0042]      FIG. 7A  is a configuration illustrating a sensor PCB shown in  FIG. 5 ; 
           [0043]      FIG. 7B  is a configuration illustrating a heat-proof plate shown in  FIG. 5 ; and 
           [0044]      FIG. 8  is a combination of the configurations shown in  FIG. 7A  and  FIG. 7B . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0045]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawing. 
         [0046]    Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to  FIGS. 5 to 8 . 
         [0047]      FIG. 5  is a configuration of an apparatus of driving a plasma display panel according to an embodiment of the present invention, and  FIG. 6  is a configuration of the plasma display panel shown in  FIG. 5  rotated by 180°. 
         [0048]    Referring to  FIGS. 5 and 6 , a PDP according to the present invention includes: a panel  30 ; a heat-proof plate  40 , attached on a rear surface of the panel  30 , for dissipating a heat generated upon driving the panel  30 ; a sensor PCB  50  having a temperature sensor  50  installed thereon for detecting a temperature of the panel  30 ; a controller  60  for producing different control signals in accordance with the temperature of the panel detected by the sensor PCB  50 ; and a driving circuit part  70  supplying different driving waveforms to the panel  30  in accordance with the control signals from the controller  60 . 
         [0049]    The panel  30  includes: an upper substrate  30   a  having a plurality of scan electrodes and a plurality of sustain electrodes; and a lower substrate  30   b  having a plurality of address electrodes formed in a direction crossing the scan electrodes and the sustain electrodes, and a phosphorous material layer formed on an entire surface of the substrate. A phosphorous material generates a visible ray by a discharge between the scan electrodes and the sustain electrodes and the address electrodes, and adjusts a transmittance of the visible ray to display a designated picture. 
         [0050]    The heat-proof plate  40  supports the panel  30  and serves to radiate a heat generated upon driving of the panel  30 . On a rear surface of the heat-proof plate  40 , a plurality of protrusions for fixing the heat-proof plate  40  to the sensor PCB  50  as shown in  FIG. 5  are installed, and a double-sided tape for attaching the protrusions  41  to the heat-proof plate  40  is attached. Also, when the sensor PCB  50  including the temperature sensor  52  is directly contacted to the rear surface of the heat-proof plate  40 , a heat carrying sheet  43  is attached to the heat-proof plate  40  in order to reduce an effect of vibration while effectively detecting a temperature. The heat carrying sheet  43  is contacted with the temperature sensor  52  installed in the sensor PCB  50  to carry the temperature of the panel to the sensor PCB  50 . The protrusions  41  is used to fix the sensor PCB  50  including the temperature  52 , but if a height of the protrusions  41  is low, a molding product  44  is used to uniformly keep a gap between the sensor PCB  50  and the heat-proof plate  40 . The molding proof plate  40  is made of a metal material with a good thermal conductivity, for example, aluminum (Al), for making a radiation well. 
         [0051]    Meanwhile, the protrusions  41  have a shape of a mushroom so that they are easily inserted in the sensor PCB  40  and do not easily come out from the sensor PCB  40  when they are inserted once. The heat carrying sheet  43  serves as an insulator in order to efficiently detect a temperature of the panel  30 , and includes a resin, having a heat transfer coefficient more than approximately 1.5 W/mk, where, W represents the watt, m represents a thickness, and k represents the Kelvin temperature. 
         [0052]    The sensor PCB  50  serves to detect the temperature of the panel. A plurality of holes  51  are formed to insert the protrusions  41  attached on the heat proof plate  40  in the sensor PCB  50  as shown  FIG. 6 . Also, installed on the rear surface of the sensor PCB  50  are a temperature sensor  52  for detecting a temperature of the panel  30 , a detection circuit part  53  for converting the detected temperature in a type of analog into a digital temperature, and a connector  54  for supplying the detected temperature to the controller. Meanwhile, the temperature sensor  52  contacts with the heat carrying sheet  42  attached on the rear surface of the heat-proof plate  40  to detect a temperature of the panel. 
         [0053]    The controller  60  receives the temperature of the panel detected by the connector  54  installed in the sensor PCB  50  and then supplies a control signal depending on the temperature of the panel detected by a detection circuit part  53  to the driving circuit part  70 . Once again, the control signals from the controller  60  differ from each other in accordance with the detected temperature of the panel. 
         [0054]    The driving circuit part  70  supplies a driving waveform depending on the control signal, that is, the detected temperature of the panel  30 , supplied from the controller  60  to the panel  30 . Once again, the driving waveforms from the driving circuit part  70  differ from each other in accordance with the control signal from the controller  60 . 
         [0055]    As set forth above, according to the present invention of the apparatus of driving the PDP, the sensor PCB  50  having the temperature sensor  52  as shown in  FIG. 7A  is directly contacted to the heat-proof plate  40  attached on the rear surface of the panel  30  as shown in  FIG. 7B . Accordingly, as shown in  FIG. 8 , the temperature sensor  52  installed in the sensor PCB  50  is contacted with the heat carrying sheet  43  attached on the heat-proof plate  40 . The analog temperature of the panel detected by the temperature sensor  52  is converted into a digital temperature through the detecting circuit part  53  and then the digital temperature is supplied through the connector  54  to the controller  60 . The driving circuit part  70  supplies the driving waveforms different from each other depending on the control signals different from each other supplied from the controller  60 , that is, the detected temperature of the panel, to the panel  30 . Accordingly, it is possible to stably drive by supplying the driving waveforms depending on the detected temperature of the panel  30  to the panel  30 . 
         [0056]    As described above, the apparatus of driving the PDP according to the present invention is capable of accurately detecting a temperature of a panel by contacting the temperature sensor installed in the sensor PCB with the heat carrying sheet attached on the heat-proof plate in order to reduce an effect of vibration and effectively detect a temperature of a panel. Therefore, it is possible to stably drive by supplying the driving waveforms in accordance with an accurately detected temperature of the panel to the panel. 
         [0057]    Although the present invention has been explained by the embodiments shown in the drawings described above, it should be understood to the ordinary skilled person in the art that the invention is not limited to the embodiments, but rather that various changes or modifications thereof are possible without departing from the spirit of the invention. Accordingly, the scope of the invention shall be determined only by the appended claims and their equivalents.