Patent Publication Number: US-2012044278-A1

Title: Display apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     1. Technical Field 
     The present disclosure relates to a display apparatus. 
     2. Background Art 
     In general, various electronics such as mobile communication terminals, digital cameras, notebooks, monitors, televisions, etc. are include display apparatuses for displaying images. 
     As our information society develops, needs for diverse forms of display apparatuses are increasing. Accordingly, research has been carried out on various display apparatuses such as liquid crystal display devices (LCDs), plasma display panels (PDPs), electro luminescent displays (ELDs), and vacuum fluorescent displays (VFDs). 
     DISCLOSURE OF THE INVENTION 
     Technical Problem 
     Embodiments provide a display apparatus in which an outer appearance thereof is improved to allow a user to feel an esthetic appearance. 
     Technical Solution 
     In one embodiment, a display apparatus includes: a display module; a thermal reaction pattern changing according to a temperature; a heater generating heat to vary a temperature of the thermal reaction pattern; and a controller controlling the heat generation of the heater, wherein the thermal reaction pattern changes in synchronization with a signal inputted into the controller. 
     In another embodiment, a display apparatus including a display area on which an image is displayed and a non-display area on which an image is not displayed includes: a display module; a thermal reaction pattern disposed on the non-display area, the thermal reaction pattern changing according to a temperature; and a heater generating heat to vary a temperature of the thermal reaction pattern, wherein the thermal reaction pattern is displayed or not displayed on the non-display area according to an image appearing on the display area. 
     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
     Advantageous Effects 
     According to the embodiments, the pattern disposed on the front surface of the display apparatus may change in synchronization with the input signal through the temperature control. Thus, the outer design of the display apparatus may be improved to perform the main function for displaying an image and also improve user&#39;s sensitive satisfaction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a display apparatus according to an embodiment. 
         FIG. 2  is a schematic view illustrating a display area and a non-display area of the display apparatus. 
         FIG. 3  is a sectional view of a structure including a thermal reaction pattern according to an embodiment. 
         FIG. 4  is a graph illustrating results obtained by measuring a temperature change according to constitutions of a heat transfer layer including the thermal reaction pattern. 
         FIG. 5  is a graph illustrating results obtained by measuring a temperature change according to voltages applied to a heater. 
         FIGS. 6 and 7  are views of a thermal reaction pattern according to a first embodiment. 
         FIG. 8  is a view of a heater according to an embodiment. 
         FIG. 9  is a block diagram of a controller according to an embodiment. 
         FIG. 10  is a circuit diagram illustrating a voltage regulator of  FIG. 9  according to an embodiment. 
         FIG. 11  is a circuit diagram illustrating a switching part of  FIG. 9  according to an embodiment. 
         FIG. 12  is a circuit diagram illustrating a power supply part of  FIG. 9  according to an embodiment. 
         FIG. 13  is a circuit diagram illustrating a MICOM of  FIG. 9  according to an embodiment. 
         FIG. 14  is a circuit diagram illustrating a relay of  FIG. 9  according to an embodiment. 
         FIGS. 15 to 18  are views of a thermal reaction pattern according to a second embodiment. 
         FIG. 19  is a view of a heater according to another embodiment. 
         FIG. 20  is view of a thermal reaction pattern according to a third embodiment. 
         FIGS. 21 to 23  are views of a thermal reaction pattern according to a fourth embodiment. 
         FIG. 24  is view of a thermal reaction pattern according to a fifth embodiment. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, that alternate embodiments included in other retrogressive inventions or falling within the spirit and scope of the present disclosure can easily be derived through adding, deleting, and changing, and will fully convey the concept of the invention to those skilled in the art. 
     In the following explanation, the terms “include/comprise” do not exclude different elements or steps from those enumerated. 
       FIG. 1  is a block diagram of a display apparatus according to an embodiment. The display apparatus may include a display module  100 , a controller  110 , a heater  120 , and a thermal reaction pattern  130 . 
     Referring to  FIG. 1 , the display module  100  emits light according to an inputted image signal to display an image. The display module  100  may be a liquid crystal display module. In this case, the display module may include a liquid crystal panel (not shown) and a backlight unit (not shown). 
     The liquid crystal panel (not shown) may display an image using light supplied from the backlight unit (not shown). For this, the liquid crystal panel (not shown) may include a liquid crystal layer, a TFT substrate, and a color filter substrate. Here, the TFT substrate and the color filter substrate face each other with the liquid crystal layer therebetween. 
     However, exemplary embodiments are not limited to the above-described liquid crystal display apparatus. For example, the exemplary embodiments may be applied to various display apparatuses such as plasma display panels (PDPs), electro luminescent displays (ELDs), and vacuum fluorescent displays (VFDs). 
     The controller  110  may generate a control signal for controlling the heater  120  using a signal inputted from the display module  100 . Also, the controller  110  may supply the control signal into the heater  120  to control heat generation of the heater  120 . 
     The heater  120  may generate heat according to the control signal inputted from the controller  110  to apply the heat to the thermal reaction pattern  130 . Then, the thermal reaction pattern  130  may be changed in temperature by the applied heat. 
     The thermal reaction pattern  130  may be disposed on a front surface of the display apparatus to allow a user to view the inside of the display apparatus. Also, the thermal reaction pattern  130  may include a thermochromic pigment that changes in color on the basis of a preset critical temperature. 
     The thermal reaction pattern  130  may vary in temperature by the heat generated from the heater  120 . In detail, the thermochromic pigment may change in color according to a temperature change, and thus the thermal reaction pattern  130  including the thermochromic pigment may vary in temperature. 
     For example, the thermal reaction pattern  130  may include a thermochromic pigment that changes in color on the basis of a critical temperature. Also, the thermal reaction pattern  130  may change in color so that specific patterns, characters, or numerals appear or disappear according to a temperature change due to the heat generated in the heater  120 . 
     The thermochromic pigment may be one of thermo pigments. That is, the thermochromic pigment is a special pigment that changes from a colorlessness into a color or from a color to other colors when the temperature exceeds a reference temperature on the basis of a predetermined reference temperature range. A color change temperate range may vary according to production conditions. However, a generally allowable temperature range may be about 15 degrees below zero to about 70 degrees above zero. A color concentration may vary according mixing conditions of pigments. 
     Also, as described above, the thermal reaction pattern  130  may change in synchronization with a signal inputted to the controller  110 . The signal inputted to the controller  110  may be a signal inputted from the outside of the display apparatus or a signal generated in the display apparatus. 
     For example, the signal inputted to the controller  110  may be a signal having information with respect to a power on/off state of the display apparatus, a signal having information with respect to an inputted image or voice signal, a signal generated in the display apparatus such as a signal having information with respect to an external input mode, a signal inputted by a user through a user input unit such as a remote controller or on screen display (OSD), or a signal inputted from an external apparatus of the display apparatus. 
     In the display apparatus according to an embodiment, the controller  110  may control the heater  120  so that the thermal reaction pattern  130  changes in synchronization with the operation of the display apparatus. 
     That is, the controller  110  may receive a signal supplied from the display module  100 , e.g., a signal having information with respect to the operation of the display module  100  to generate a control signal according to the inputted signal, thereby supplying the control signal into the heater  120 . Then, the heater  120  may generate heat according to the supplied control signal to change a temperature of the thermal reaction pattern  130 . As a result, the thermal reaction pattern  130  may change in synchronization with the operation of the display module  100 . 
     According to the current embodiment, the thermal reaction pattern  130  may change in synchronization with the operation of the display module  100  at an operation time point of the display module  100 . That is, the controller  110  may receive information with respect to the present operation state of the display module  100  to control the heater  120  so that the thermal reaction pattern  130  is displayed during a preset specific operation period of the display module  100 . For example, the controller  110  may apply the control signal to the heater  120  to apply the heat to the thermal reaction pattern so that patterns depending on the thermal reaction pattern  130  appear during a predetermined time from a time point at which the supply of a power into the display module  100  starts. 
     According to another embodiment, the thermal reaction pattern  130  may change in synchronization with an image displayed on the display module  100 . In this case, the controller  110  may receive information with respect to the present image displayed on the display module  100  to control the heater  120  so that the thermal reaction pattern  130  changes to correspond to the displayed image. For example, when a preset specific image is displayed on the display module  100 , the controller  110  may control the heater  120  so that a pattern corresponding to the specific image appears using the thermal reaction pattern  130 . 
     According to further another embodiment, the thermal reaction pattern  130  may change in synchronization with a kind of signal inputted to the display module  100 . That is, the controller  110  may receive information with respect to the signal inputted to the display module  100  to control the heater  120  so that the thermal reaction pattern  130  changes to correspond to a kind of inputted signal. That is, when an image corresponding to a preset kind of signal is displayed on the display module  100 , the controller  110  may control the heater  120  so that a pattern corresponding to the signal appears using the thermal reaction pattern  130 . 
     For example, the signal inputted to the display module  100  may be distinguished according to whether the signal is an image signal or a voice signal such as a DVD signal, an AVI signal, an SD image signal, an HD image signal, and an MP3 signal, or distinguished according to a resolution when the signal is the image signal. Thus, the pattern corresponding to a kind of distinguished input signal may appear using the thermal reaction pattern  130 . 
       FIG. 2  is a schematic view illustrating a display area and a non-display area of the display apparatus. That is,  FIG. 2  illustrates a front surface of the display apparatus  200 , i.e., a shape of the display apparatus  200  when viewed from a user side. 
     Referring to  FIG. 2 , the display apparatus  200  may include a display area  210  on which an image is displayed on the display apparatus  200  and a non-display area  220  on which an image is not displayed. The non-display area  220  may be disposed on an outer area of the display apparatus  200  to surround the display area  210 . In general, a light blocking pattern may be disposed on the non-display area. 
     Thus, mechanisms disposed outside the display area  210  within the display apparatus  200  except for an image to be displayed may be not seen by the user due to the non-display area  220 . 
     According to the current embodiment, as shown in  FIG. 1 , the thermal reaction pattern  130  may be disposed on the non-display area  220  on which an image is not displayed to improve an outer appearance of the display apparatus  200  without affecting the image to be watched by the user. 
       FIG. 3  is a sectional view of a structure including the thermal reaction pattern  130  according to an embodiment. 
     Referring to  FIG. 3 , a transparent window  300  may be disposed on a front surface of the display module  100  to transmit light emitted from the display module  100 . Also, the transparent window  300  may protect the display module  100  against an external impact. For example, the transparent window  300  may be formed of a plastic material such as acrylic or a glass material having impact resistance and light transmittance. Also, the transparent window  300  may be formed of a film material such as polyethylen terephthalate (PET) and attached to the front surface of the display module  100 . 
     As described above, the heater  120  may generate heat according to a heating voltage supplied from the controller  110  to change a temperature of the thermal reaction pattern  130  according to the heat generation of the heater  120 . 
     The heater may include a plurality of film heaters. Here, a thin film may be coated with carbon heaters connected to each other in parallel and an electrode may be disposed using a cooper film, and then the films may be laminated to manufacture each of the film heaters. When a voltage is applied to the film heaters, the carbon heaters connected in parallel generate heat. As a result, the heater  120  may generate heat. 
     In this case, the control signal supplied from the controller  110  to the heater  120  may be realized as a heating voltage applied to the film heaters. Thus, the controller  110  may control the heating voltage to control the heat generation of the heater  120 . 
     A heat transfer layer  310  may be disposed between the transparent window  300  and the heater  120 . The thermal reaction pattern  130  may be disposed on one surface of the heat transfer layer  310 . The heat generated in the heater  120  may be transferred into the thermal reaction pattern  130  through the heat transfer layer  310 . 
     For example, since the thermochromic pigment exists in powder or compressed form at room temperature, the thermochromic pigment may be mixed with a diluting agent to change into ink form and then the mixture may be printed on one surface of the heat transfer layer  310  using a silk screen or spray injection process to manufacture the heat reaction pattern  130 . 
     As described above, the thermal reaction pattern  130  may include the thermochromic pigment that changes in color on the basis of the critical temperature. Thus, when the heater  120  may heat to reach the critical temperature, the thermal reaction pattern  130  may change so that patterns, characters, or numerals printed with the thermochromic pigment appear. 
     For example, the thermochromic pigment constituting the thermal reaction pattern  130  may show a black color at the preset critical temperature and a colorlessness at a temperature greater than the critical temperature. Thus, the thermochromic pigment may be printed on the non-display area to form the thermal reaction pattern  130 . 
     In this case, when the thermal reaction pattern  130  has a temperature less than the critical temperature, the thermochromic pigment may show the black color. Thus, the pattern printed with the thermochromic pigment may not visually appear. However, when the thermal reaction pattern  130  has a temperature greater than the critical temperature by the heating of the heater, the pattern printed with the thermochromic pigment may appear. 
     Also, the thermochromic pigment may change into different colors except for the black color at a temperature greater than the critical temperature. 
     As described above, to change the thermal reaction pattern  130  in synchronization with the operation of the display module  100 , the heater  120  may generate heat under the control of the controller  110  to allow a temperature of the thermal reaction pattern  130  to reach the critical temperature. 
     That is, to prevent the temperature of the thermal reaction pattern  130  from reaching the critical temperature due to external parameters except for the heating of the heater  120  under the control of the controller  110 , e.g., an increase of an ambient temperature of the display apparatus  200 , the thermochromic pigment may have a critical temperature greater than an allowable maximum temperature of the ambient temperature. 
     Also, since the maximum temperature may be different according to national or local area, the thermal reaction pattern  130  may be manufactured using thermochromic pigments having critical temperatures different from each other according to the national or local area. 
     For example, when it is assumed that a maximum temperature of summer in Korea is about 38 degrees, the thermochromic pigment may be manufactured to have a critical temperature greater than about 38 degrees. When the display apparatus  200  is used for an area having a temperature less than the maximum temperature such as Russia, the thermochromic pigment may be manufactured to have a critical temperature less than about 38 degrees, thereby reducing power consumption for displaying the thermal reaction pattern  130 . Also, in case of an area having a high maximum temperature such as Africa, the thermochromic pigment may be manufactured to have a critical temperature greater than about 40 degrees. 
     Regardless of the control of the controller  110 , as the ambient temperature of the display apparatus  200  increases above the critical temperature of the thermal reaction pattern  130 , it may be necessary to prevent the thermal reaction pattern  130  from being displayed at an undesired time point. 
     For this, the display apparatus  200  according to the current embodiment may further include a temperature measurement part (not shown) for measuring a temperature of the thermal reaction pattern  130  and a cooling part (not shown). 
     For example, the temperature measurement part (not shown) measures a temperature of the thermal reaction pattern  130  or the heat transfer layer  310  on which the thermal reaction pattern  130  is printed. When the measured temperature increases to approach the critical temperature, it is determined whether the temperature increases by heat generated in the heater  120  according to the control signal outputted from the controller  110 , i.e., whether a heating start signal for starting the heating of the heater  120  is outputted from the controller  110 . 
     When the determination result shows that the temperature of the thermal reaction pattern  130  approaches the critical temperature even though the heating start signal is not outputted from the controller  110 , the cooling part (not shown) cools the thermal reaction pattern  130  to decrease the temperature of the thermal reaction pattern  130 . Thus, it may prevent the thermal reaction pattern  130  from changing by the increase of the ambient temperature at the undesired time point. 
     Also, when excessive heat is generated from the heater  120  to allow the temperature of the thermal reaction pattern  130  to reach the critical temperature, driving circuits may be damaged by the heat of the heater  120  to affect the operation of the display module  100 . Thus, to prevent the heat from affecting the operation of the display module  100 , the thermochromic pigment included in the thermal reaction pattern  130  may have a critical temperature equal to or less than about 50 degrees. 
     The heat transfer layer  310  may be formed of one of paper, acrylic, aluminum (Al), and copper (Cu). 
     When the heat transfer layer  310  is formed of one of paper, Al, and Cu, the thermal reaction pattern  130  may be disposed on a front surface of the heat transfer layer  310  to allow the user to see the thermal reaction pattern  130 . 
     Also, when the heat transfer layer  310  is formed of transparent acrylic, the thermal reaction pattern  130  may be disposed on a back surface of the heat transfer layer  310 . 
     The front surface of the heat transfer layer  310  represents a surface adjacent to the transparent window  300  of both sides of the heat transfer layer  310 , and the back surface represents a surface adjacent to the heater  120 . 
       FIG. 4  illustrates experimental results obtained by measuring a temperature change depending on a time at each of the paper, Al, and Cu constituting the heat transfer layer  310 . That is,  FIG. 4  illustrates results obtained by measuring a temperature change of each materials when a voltage having about 15V is applied to the heater  120  constituted by the film heaters. 
     Referring to  FIG. 4 , all of the paper, Al, and Cu may reach a temperature of about 38 degrees to about 50 degrees that are critical temperature within about 3 seconds. However, when the heat transfer layer  310  formed of paper, Al, or Cu is disposed between the thermal reaction pattern  130  and the heater  120 , a thermal resistance may occur. Also, the more the thermal resistance increases, the more a time for which a temperature of the thermal reaction pattern  130  reaches the critical temperature by the heating of the heater  120  increases. 
     Al may generate a thermal resistance of about 0.05° C./w, and Cu may generate a thermal resistance of about 0.026° C./w. On the other hand, since the paper may form the thermal transfer layer  310  having a thickness of a micro unit, i.e., a thickness significantly less than that of Al or Cu, the thermal resistance may be very less. Thus, a time for which a temperature of the thermal reaction pattern  130  reaches the critical temperature may be reduced. 
     According to the current embodiment, a structure including the thermal reaction pattern  130  described with reference to  FIG. 3  may be disposed on the non-display area of the display apparatus  200 . 
     In this case, the heat transfer layer  310  contacting the heater  120  may be manufactured using a paper having a black color. Then, the thermochromic pigment may be printed on the front surface of the heat transfer layer  310  formed of the black paper to manufacture the thermal reaction pattern  130 . Also, since the thermochromic pigment has a black color at a temperature less than the critical temperature and a colorlessness at a temperature greater than the critical temperature, the pattern printed with the thermochromic pigment may be visually seen by the user only when the temperature of the thermal reaction pattern  130  reaches the critical temperature. 
     The thermochromic pigment may have colors different from the black color except for the above-described colorlessness at a temperature greater than the critical temperature. 
     The heat transfer layer  310  formed of the paper may have a light block effect for covering the non-display area  220  of the display apparatus  200 . For this, the heat transfer layer  310  formed of the paper may have a thickness d of about 0.15 mm or more. 
     Also, the heat transfer layer  310  should have a low thermal resistance enough to allow a temperature of the thermal reaction pattern  130  to reach a critical temperature greater than about 38 degrees within three seconds. For this, the heat transfer layer  310  formed of the paper may have a thickness d of about 0.5 mm or less. 
       FIG. 5  is a graph illustrating results obtained by measuring a temperature change according to voltages applied to the heater  12 . For example,  FIG. 5  illustrates results obtained by measuring temperatures changing by supplying heating voltages of about 5V, 10V, 15V, and 20V to the heater  120  constituted by the film heaters described with reference to  FIG. 3 . 
     Referring to  FIG. 5 , when a voltage of about 10V or more is supplied to the heater  120 , a temperature of the heater  120  may reach a temperature of about 38 degrees or more that is the critical temperature of the thermal reaction pattern  130  with three seconds. However, when a voltage greater than about 15V is supplied to the heater  120 , a temperature of the heater  130  may reach a high temperature approaching about 70 degrees. Thus, the display module  100  may be affected in operation by the temperature. 
     Thus, to allow a temperature of the thermal reaction pattern  130  to reach the critical temperature within a quick time, e.g., three seconds without affecting the operation of the display module  100 , a voltage supplied from the controller  110  to the heater  120  may range about 10 V to about 15 V. 
       FIG. 6  is a view of a thermal reaction pattern appearing on a front surface of a display apparatus according to a first embodiment. 
     Referring to  FIG. 6 , a thermal reaction pattern  400  formed of a thermochromic pigment such as a thermo pigment may be disposed on a non-display area  220  of a front surface of a display apparatus  200 . In detail, a paper printed with the thermochromic pigment may be disposed on a back surface of a transparent window exposed toward a user as described with reference to  FIG. 3 , and a heater for generating heat may be disposed on a back surface of the paper. 
     Referring to  FIG. 6 , a specific pattern may be printed using the thermochromic pigment such as thermo pigment on a side of the non-display area  220  to manufacture the thermal reaction pattern  400 . Thus, the thermal reaction pattern  400  may change in temperature by heat generated in the heater  120  disposed adjacent thereto. 
     That is, the heater  120  may generate heat under the control of a controller  110 . Thus, the thermal reaction pattern  400  may increase in temperature by the generated heat. When a temperature of the thermal reaction pattern  400  reaches a preset critical temperature, the thermochromic pigment may change in color. 
     In more detail, the non-display area  200  of the display apparatus  200  has a black color, and the thermochromic pigment printed with the specific pattern on the non-display area  220  may have a black color at a temperature less than the critical temperature and a specific color, e.g., a pink color at a temperature greater than the critical temperature. 
     In this case, the controller  110  may supply a heating voltage to a temperature of the heater  120 , and thus a temperature of the thermochromic pigment constituting the thermal reaction pattern  400  may reach the critical temperature with several seconds to show the pattern of thermal reaction pattern  400  printed with the thermochromic pigment. 
     The pattern of the thermal reaction pattern  400  printed with the thermochromic pigment as shown in  FIG. 6  may be shown in synchronization with an operation time point of the display module  100 . 
     According to an embodiment, the pattern of the thermal reaction pattern  400  printed with the thermochromic pigment may appear for a predetermined time after a voltage is supplied to the display apparatus. 
     For example, when the user pushes a power switch of the display apparatus, the power supply into the display module  100  may start. Then, the controller  110  may receive a signal for informing the start of the power supply from the display module  100 . Thereafter, the controller  110  may supply a preset heating voltage to the heater  120  to generate heat through the heater  120 . 
     When a temperature of the thermochromic pigment constituting the thermal reaction pattern  400  reaches a critical temperature by the heat generated by the heater  120 , a pattern of the thermal reaction pattern printed with the thermochromic pigment may appear. Also, after a predetermined time elapses, the controller  110  may stop the supply of the heating voltage. Thus, the heating of the heater  120  may be stopped to decrease the temperature of the thermochromic pigment to a temperature less than the critical temperature. As a result, after a predetermined time elapses after a voltage is supplied to the display apparatus, the visibly appearing pattern of the thermal reaction pattern  400  printed with the thermochromic pigment may disappear. 
     When a power is supplied to the display module  100 , a power on sequence period for displaying an image exists. Here, an image is not displayed for the power one sequence period. Thus, it may take about ten seconds until the image is displayed after the user pushes the power switch of the display apparatus. 
     Thus, the controller  110  may allow the pattern printed with the thermochromic pigment to appear on the non-display area  220  after a power is supplied to the display module  100  and also allow the pattern to disappear before the image is displayed to control the pattern of the thermal reaction pattern  400  printed with the thermochromic pigment so that the pattern appears for about three seconds to about six seconds. 
     As described above, since the pattern allow the user to feel an esthetic appearance may be visibly expressed on the non-display area  220  for a time until the image is displayed after the power is supplied, it may prevent the user from feeling boring for the standby time. 
     Referring to  FIG. 7 , the thermal reaction pattern  400  may be divided into a plurality of areas. The divided areas may independently change in temperature by the control of the controller  110 . 
     For example, the heater disposed under the heat transfer layer on which the thermal reaction pattern  400  is printed may include a plurality of heating units independently controlled by the controller  110 . As described above, since the heater is divided into the plurality of heating units, the thermal reaction pattern  400  may be divided into a plurality of areas corresponding to the heating units. 
     That is, when the heater includes n heating units, the thermal reaction pattern disposed above the heater may be divided into n areas. Here, the divided n areas and the n heating units may overlap each other in position. 
     Referring to  FIG. 7 , the divided areas of the thermal reaction pattern  400  may be successively operated with a time interval. Thus, a portion of the pattern printed with the thermochromic pigment may visibly appear according to a time and then the whole pattern may gradually appear. 
     According to an embodiment, a lowermost portion of the pattern printed with the thermochromic pigment may visibly appear at an initial time point at which the thermal reaction pattern  400  appears as shown in  FIG. 7A . Thereafter, as shown in  FIGS. 7B to 7E , upper portions of the pattern may successively appear. Then, as shown in  FIG. 7F , the whole pattern printed with the thermochromic pigment may appear at a final time point. 
     As described above, since the thermal reaction pattern  400  may be divided in the plurality of area and successively operated, the pattern printed with the thermochromic pigment may gradually appear. Thus, this may allow the user to feel an esthetic appearance to further improve the design effect of the display apparatus. 
       FIG. 8  is a view of the heater  120  according to an embodiment. As described above,  FIG. 8  illustrates a structure of a heater  120  in which a thermal reaction pattern  400  is divided into a plurality of areas and independently operated. 
     Referring to  FIG. 8 , the heater  120  may include a plurality of heating units  500  to  590 . The plurality of heating units  500  to  590  may receive a control signal from a controller  110  and be independently operated. Also, the plurality of heating units  500  and  590  may be disposed on positions corresponding to the plurality of divided areas of the thermal reaction pattern  400 . 
     For example, as shown in  FIG. 8 , when the heater  120  includes ten heating units  500  to  590 , the thermal reaction pattern  400  may be displayed on ten areas corresponding to the heating units  500  to  590 , respectively. In this case, the controller  110  may supply a heating voltage to the heating unit disposed at a position corresponding to a specific area of the thermal reaction pattern  400  to visibly show the specific area of the thermal reaction pattern  400 . 
     That is, the heating voltage may be successively supplied from a lower end toward an upper end into the heating units  500  to  590  with a predetermined time interval to allow the pattern printed with the thermochromic pigment to gradually appear on a non-display area as shown in  FIG. 7 . In more detail, when the pattern printed with the thermochromic pigment is gradually expressed for five seconds using the ten heating units  500  to  590 , the controller may successively supply the heating voltage into the heating units  500  to  590  with a time interval of about 0.5 seconds. 
     Also, each of the heating units  500  to  590  may include one or more film heaters. 
     The present disclosure is not limited to the control method described with reference to  FIGS. 7 and 8 . That is, the visibly appearing order of the divided areas of the thermal reaction pattern  400  or the position and number of the heating units included in the heater  120  may vary as necessary. 
       FIG. 9  is a block diagram of a controller  110  according to an embodiment. The controller may include an adapter  111 , a switching part  112 , a voltage regulator  113 , a power supply part  114 , a MICOM  115 , and a plurality of relays  116  to  118 . 
     The adapter  111  supplies a heating voltage supplied from the controller  110  into the heater  120 , and the voltage regulator  113  drops down the supplied voltage to supply the down voltage into the switching part  112 . 
       FIG. 10  is a view of the voltage regulator  113  according to an embodiment. The voltage regulator  113  drops down a voltage of about 12 V supplied from the adapter  111  into about 5 V to supply the voltage to the switching part  112 . 
     Also,  FIG. 11  is a view of the switching part  112  according to an embodiment. When the switching part  112  is turned on, a voltage is supplied into the plurality of relays  116  to  118  through the power supply part  114  as shown in  FIG. 12 . 
     The MICOM  115  controls the plurality of relays  116  to  118  using the voltage of about 12 V supplied from the power supply part  114 .  FIG. 13  is a view of the MICOM  115  according to an embodiment. 
     The plurality of relays  116  to  118  may correspond to the heating units independently operated as described above, respectively. That is, as shown in  FIG. 8 , when the heater  120  includes the ten heating units  500  to  590 , the ten relays may be connected corresponding to the ten heating units  500  to  590 . 
     The plurality of relays  116  to  118  may supply a heating voltage to the corresponding heating units under the control of the MICOM. That is, according to a control signal inputted from the MICOM  115 , the plurality of relays  116  to  118  may supply a heating voltage into the whole heating units or a portion of the heating units, or successively supply a heating voltage into the heating units. 
     Since the method in which the plurality of relays  116  to  118  supply the heating voltage under the control of the MICOM  115  is equal to the control method of the controller  110  as described with reference to  FIGS. 7 and 8 , its descriptions will be omitted. 
       FIG. 14  is a view illustrating one of the relays  116  to  118  according to an embodiment. One heating unit may be connected to the illustrated relay  600 . The heating unit may include a plurality of film heaters  610  to  640  connected to each other. 
     Referring to  FIG. 14 , the plurality of film heaters  610  to  640  may be connected to an output terminal of the relay  600 . The relay  600  may supply a heating voltage of about 12 V supplied through the power supply part  114  into the plurality of film heaters  610  to  640  according to a control signal inputted from the MICOM  115 . 
       FIGS. 15 to 18  are views of a thermal reaction pattern according to a second embodiment. The thermal reaction pattern may change in synchronization with an image displayed on a display module  100 . 
     Referring to  FIGS. 15 to 18 , characters such as “Antenna”, “Cable”, “External input”, and “HDMI” may be printed on a lower end of a non-display area of a display apparatus using a thermochromic pigment such as thermo pigment to manufacture a thermal reaction pattern. 
     In the case, a controller  110  may receive a signal informing an input mode of a presently displayed image from the display module  100  to control a heater  120  according to the inputted signal, thereby change a thermal reaction pattern disposed on a non-display area. 
     For example, when the presently displayed image is an image inputted through the antenna from the display module  100 , the controller  110  may supply a heating voltage to a heating unit  700  of a plurality of heating units  700  to  730  corresponding to an area on which the character “Antenna” is printed using the thermochromic pigment as shown in  FIG. 19 . In this case, as shown in  FIG. 15 , the character “antenna” informing the image input mode may appear on a lower end of the non-display area. 
     As shown in  FIGS. 16 to 18 , for informing an image input mode such as “Cable”, “External input”, or “HDMI” on the lower end of the non-display area using the thermal reaction pattern, the controller  110  may supply a heating voltage to the corresponding heating unit of the plurality of heating units  700  to  730 . 
       FIG. 20  is view of a thermal reaction pattern according to a third embodiment. The thermal reaction pattern may change in synchronization with a time set by a user. 
     Referring to  FIG. 20 , a tune-off time of a display apparatus may be previously set through reservation set-up of a user. When a power supply into a display module  100  is blocked at the corresponding time, a character “Power off” printed with the thermochromic pigment may appear on an upper end of the non-display area. 
     In this case, the heater  120  may be disposed on only an area of the thermal reaction pattern printed with the thermochromic pigment of the upper end of the non-display area. The controller  110  may supply a hating voltage to the heater  120  at a time set by the user to display the character “Power off” on an upper portion of the non-display area as shown in  FIG. 20 . 
       FIGS. 21 to 23  are views of a thermal reaction pattern according to a fourth embodiment. The thermal reaction pattern may change in synchronization with a kind of signal inputted into a display module from the outside. 
     For example, the controller  110  may receive information with respect to a kind of input signal from the display module  100  and selects one of a plurality of heating units according to the kind of input signal to supply the heating voltage to the selected heating unit. 
     In more detail, when the input signal is a DVD image/voice signal, the controller  110  may receive a signal having information that an input signal is the DVD image/voice signal from the display module  100  to supply a heating voltage into the heating unit corresponding to an area on which a character “DVD” is printed with the thermochromic pigment. Thus, as shown in  FIG. 21 , the character “DVD” that informs the kind of input signal may appear on a right side of the non-display area. 
     Also, as shown in  FIGS. 22 and 23 , when the input signal is an AVI signal or MP3 voice signal, the controller  110  may supply a heating voltage into the heating unit corresponding to an area on which a character informing a kind of corresponding input signal is printed with the thermochromic pigment to express the kind of input signal on a right side of the non-display area. 
     Although the thermal reaction pattern is disposed on the non-display area  220  of the display apparatus  200  according to the current embodiment, the thermal reaction pattern may be disposed on a front surface of the display apparatus  200  including a display area  210 . 
       FIG. 24  is view of a thermal reaction pattern according to a fifth embodiment. Here, the thermal reaction pattern may be disposed on the entire area of a front surface of the display apparatus  200 . 
     Referring to  FIG. 24 , the thermal reaction pattern may be disposed on the front surface of the display apparatus  200  including a display area  210 . As a temperature of the thermal reaction pattern increases at a temperature greater than a critical temperature, the thermal reaction pattern disposed on the front surface of the display apparatus  200  may be displayed. 
     However, light emitted from the display module  100  should be emitted through a front surface of the display area  210 . Thus, the thermochromic pigment constituting the thermal reaction pattern may not visibly appear because the thermochromic pigment is transparent at a temperature less than the critical temperature. Also, the thermochromic pigment may have a special color at a temperature greater than the critical temperature. In addition, a heater  120  may be disposed on a non-display area  220  to increase a temperature of the thermal reaction pattern. 
     Also, the thermal reaction pattern may be directly printed on one surface of a transparent window  300  disposed on a front surface of the display module  100 . Alternatively, the thermal reaction pattern may be printed on one surface of a transparent heat transfer layer disposed under the transparent window, e.g., an acrylic plate. 
     When the heater  120  is disposed on the non-display area  220 , heat may be not well transferred into a portion away from the non-display area  220 , e.g., a thermochromic pigment printed on a central portion. Thus, a layer on which the thermal reaction patter is printed may be formed of a material having high conductivity as well as high light transmittance. 
     Also, when the heater  120  includes a transparent layer having high transmittance, the heater  120  may be disposed on the entire front surface of the display apparatus  200 , e.g., a front surface of the transparent window including the thermal reaction pattern. 
     As shown in  FIG. 24 , the thermal reaction pattern disposed on the front surface of the display apparatus  200  may be displayed at a time point at which the display apparatus  200  becomes power-off. 
     For example, the controller  110  may control the heat generation of the heater  120  so that the thermal reaction pattern is displayed from a time point at which the display apparatus  200  becomes power-off to a time point at which the display apparatus  200  becomes power-on. 
     Also, the thermal reaction pattern may be displayed on the front surface of the display apparatus  200  according to a user&#39;s input. For example, when the user inputs a specific key through an input unit disposed on a remote control or the display apparatus  200 , the thermal reaction pattern may appear or disappear on the front surface of the display apparatus  200  as shown in  FIG. 12 . 
     Also, the user may set a specific time period in which the thermal reaction pattern is displayed through an on screen display menu of the display apparatus  200 . Alternatively, the user may set so that the thermal reaction pattern is displayed for a predetermined time from a time point at which the display apparatus  200  becomes power-off. 
     However, at the time point at which the display apparatus  200  become power-on, the controller  110  may control the heater  120  to stop the heat generation of the heater  120  so that the thermal reaction pattern displayed on the front surface disappears. Also, in the state of the power-on of the display apparatus  200 , the controller  110  may control the heater  120  so that the thermal reaction pattern is not displayed even though the user&#39;s input or reservation set-up is performed. 
     As described above, the thermal reaction pattern of the pattern that allow the user to feel the esthetic appearance may be displayed on the front surface of the display apparatus  200  during the power-on of the display apparatus  200 . Also, an interior function such as a picture frame in addition to the function of the display apparatus  200  may be added during the power-off of the display apparatus  200  to improve the outer appearance and utilization of the display apparatus  200 . 
     According to the embodiments, the pattern disposed on the front surface of the display apparatus may change in synchronization with the input signal through the temperature control. Thus, the outer design of the display apparatus may be improved to perform the main function for displaying an image and also improve user&#39;s sensitive satisfaction. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 
     INDUSTRIAL APPLICABILITY