JP2009288668A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable display device that can prevent the load of a data wiring drive circuit from being increases even when a display part has a large screen. <P>SOLUTION: The liquid crystal display device in which a liquid crystal panel has a plurality of source wiring lines S1 to SM and a plurality of gate wiring lines G1 to GN arrayed in a matrix form, and a plurality of pixels P includes: source drivers 23-1 to 23-5 connected to respective one-end sides of the source wiring lines S1 to SM; source drivers 23-6 to 23-10 connected to respective other-end sides of the source wiring lines S1 to SM; and a temperature detection unit 22 which detects the ambient temperature of the liquid crystal panel 2. A panel control unit 21 limits data signals output from at least the source drivers 23-1 to 23-5 or 23-6 to 23-10 to the source wiring lines S1 to SM using the detection result of the temperature detection unit 22. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device having a display unit in which a plurality of data lines and a plurality of scanning lines are arranged in a matrix.

  In recent years, for example, liquid crystal display devices have been widely used in liquid crystal televisions, monitors, mobile phones, and the like as flat panel displays having features such as thinness and light weight compared to conventional cathode ray tubes. Such a liquid crystal display device includes a liquid crystal panel as a display unit for displaying information such as characters and images. The liquid crystal panel includes a plurality of data wirings (source wirings) arranged in a matrix and a plurality of data wirings. A plurality of pixels having switching elements such as thin film transistors (TFTs) are provided in the vicinity of the intersection of the scanning wiring (gate wiring) and the data wiring and scanning wiring.

In addition, the conventional liquid crystal display device is provided with an ambient temperature detection circuit for detecting the ambient temperature of the liquid crystal panel, for example, as described in Patent Document 1 below, and based on the detected temperature of the ambient temperature detection circuit. A device having a control unit for controlling the output time of the source signal applied to the source wiring from the source driver has been proposed. In this conventional liquid crystal display device, the liquid crystal molecules included in the liquid crystal panel are consumed (charged) at high temperatures more easily than at low temperatures. Electricity could be reduced. That is, in this conventional liquid crystal display device, when the detected temperature is lower than the reference temperature, the source signal application output time is lengthened, and when the detected temperature is higher than the reference temperature, the source signal application output time is shortened. By doing so, it has been said that the power consumption of the liquid crystal display device can be reduced.
JP 2002-351426 A

  However, in the conventional liquid crystal display device as described above, when the screen of the display unit (liquid crystal panel) is enlarged, the load on the source driver (data wiring driving circuit) may increase. An abnormality such as a failure may occur, resulting in a problem that the reliability of the liquid crystal display device is lowered.

  Specifically, in the conventional liquid crystal display device, the source driver is connected to one end side of the source wiring (data wiring) and outputs a source signal (data signal) to the source wiring. For this reason, in this conventional liquid crystal display device, when the source line is extended along with the increase in the screen size of the display unit, the source signal is supplied to the pixel provided on the other end side of the source line. It was necessary to enlarge.

  Therefore, in a conventional liquid crystal display device, the load on the source driver increases and the source driver generates significant heat depending on the ambient temperature, the magnitude of the source signal, or the number of source lines connected to the source driver. There is a risk of exceeding the allowable operating temperature of the source driver. As a result, in the conventional liquid crystal display device, an abnormality such as a failure may occur in the source driver, leading to a decrease in reliability.

  In view of the above problems, an object of the present invention is to provide a display device with excellent reliability capable of preventing an increase in the load of a data wiring driving circuit even when the screen of a display unit is enlarged. And

In order to achieve the above object, a display device according to the present invention is provided in the vicinity of a plurality of data lines and a plurality of scanning lines arranged in a matrix, and an intersection of the data lines and the scanning lines. A display device including a plurality of pixels in a display unit,
A first data line driving circuit connected to one end of the data line and outputting a data signal corresponding to information displayed on the display unit;
A second data line driving circuit connected to the other end of the data line and outputting a data signal corresponding to information displayed on the display unit;
A temperature detection unit for detecting the ambient temperature of the display unit;
A control unit for controlling the driving of the first and second data line driving circuits;
The control unit limits a data signal output from at least one of the first and second data wiring driving circuits to the data wiring using a detection result of the temperature detection unit. is there.

  In the display device configured as described above, the first and second data wiring driving circuits are connected to one end side and the other end side of the data wiring, and the data signal is transmitted to the data wiring from the first and second data wiring lines. 2 is input from the data wiring drive circuit. In addition, a temperature detection unit that detects the ambient temperature of the display unit is provided, and the control unit outputs to the data wiring from at least one of the first and second data wiring driving circuits using the detection result of the temperature detection unit. Limit data signals. Thus, unlike the above-described conventional example, even when the screen of the display unit is enlarged, it is possible to prevent an increase in the load of the data wiring drive circuit and to easily configure a display device with excellent reliability. Can do.

  In the above display device, it is preferable that a plurality of sets of the first and second data line driving circuits are provided.

  In this case, even when the screen of the display unit is enlarged, the load on the plurality of first and second data wiring drive circuits can be surely reduced.

  In the display device, when the control unit determines that the detection result from the temperature detection unit is equal to or higher than a first threshold temperature, the control unit sends the first and second data wiring drive circuits. A data signal is output from one of the first and second data wiring driving circuits to a predetermined number of data wirings among the plurality of connected data wirings, and to the remaining data wirings, A data signal may be output from the other of the first and second data line driving circuits.

  In this case, the load of the first and second data wiring drive circuits can be appropriately distributed, and heat generation in each of the first and second data wiring drive circuits can be reliably suppressed.

  In the display device, when the control unit determines that the detection result from the temperature detection unit is equal to or higher than a second threshold temperature, the control unit detects the first and second data wiring drive circuits. Of these, it is preferable to output a data signal from only one of the data wiring driving circuits to the data wiring.

  In this case, since the other of the first and second data line driving circuits is stopped, the power consumption of the display device can be reduced.

  In the display device, it is preferable that the one of the data line driving circuits is provided below the gravity direction of the first and second data wiring driving circuits.

  In this case, of the first and second data wiring driving circuits, only the data wiring driving circuit having the lower ambient temperature is driven, and the data wiring driving circuit having the higher ambient temperature is stopped. It is possible to easily prevent an abnormality such as a failure due to temperature and heat generated by driving from occurring in the data wiring driving circuit.

  In the display device described above, a liquid crystal panel including a pair of transparent substrates and a liquid crystal layer sandwiched between the pair of transparent substrates may be used for the display unit.

  In this case, the control unit can appropriately operate the liquid crystal layer according to the detection result.

  According to the present invention, it is possible to provide a display device with excellent reliability capable of preventing an increase in the load on the data line driving circuit even when the screen of the display unit is enlarged.

  Hereinafter, preferred embodiments of a display device of the present invention will be described with reference to the drawings. In the following description, the case where the present invention is applied to a transmissive liquid crystal display device will be described as an example. Moreover, the dimension of the structural member in each figure does not faithfully represent the actual dimension of the structural member, the dimensional ratio of each structural member, or the like.

[First Embodiment]
FIG. 1 is a schematic cross-sectional view illustrating a liquid crystal display device according to a first embodiment of the present invention. In the figure, the liquid crystal display device 1 according to the present embodiment includes a liquid crystal panel 2 as a display unit installed on the upper side of the figure as a viewing side (display side), and a non-display side of the liquid crystal panel 2 (lower side of the figure). And an illuminating device 3 that generates illumination light that illuminates the liquid crystal panel 2.

  The liquid crystal panel 2 includes a liquid crystal layer 4, an active matrix substrate 5 and a color filter substrate 6 as a pair of transparent substrates sandwiching the liquid crystal layer 4, and active matrix substrate 5 and color filter substrate 6 on respective outer surfaces. Provided polarizing plates 7 and 8 are provided. Further, the liquid crystal panel 2 is provided with a driver device 9 for driving the liquid crystal panel 2 and a drive circuit device 10 connected to the driver device 9 via the flexible printed circuit board 11. The liquid crystal layer 4 can be driven pixel by pixel. In the liquid crystal panel 2, the polarization state of the illumination light incident through the polarizing plate 7 is modulated by the liquid crystal layer 4 and the amount of light passing through the polarizing plate 8 is controlled, so that a desired image is displayed. Is done.

  Note that the liquid crystal mode and the pixel structure of the liquid crystal panel 2 are arbitrary. Moreover, the drive mode of the liquid crystal panel 2 is also arbitrary. That is, as the liquid crystal panel 2, any liquid crystal panel that can display information can be used. Therefore, the detailed structure of the liquid crystal panel 2 is not shown in FIG.

  The illuminating device 3 is provided with a bottomed chassis 12 opened on the upper side (liquid crystal panel 2 side) in the figure, and a frame-like frame 13 installed on the liquid crystal panel 2 side of the chassis 12. The chassis 12 and the frame 13 are made of metal or synthetic resin and are sandwiched by a bezel 14 having an L-shaped cross section in a state where the liquid crystal panel 2 is installed above the frame 13. Thereby, the illuminating device 3 is assembled to the liquid crystal panel 2 and integrated as a transmissive liquid crystal display device 1 in which illumination light from the illuminating device 3 enters the liquid crystal panel 2.

  The illumination device 3 is provided on the inner surface of the chassis 12, the diffusion plate 15 installed so as to cover the opening of the chassis 12, the optical sheet 17 installed on the liquid crystal panel 2 side above the diffusion plate 15. And a reflective sheet 19. In the lighting device 3, a plurality of, for example, six cold cathode fluorescent tubes 20 are provided inside the chassis 12 on the lower side of the liquid crystal panel 2 to constitute a direct-type lighting device 3. And in the illuminating device 3, the light from each cold cathode fluorescent tube 20 is radiate | emitted as the said illumination light from the light emission surface of the illuminating device 3 arrange | positioned facing the liquid crystal panel 2. FIG.

  In the above description, the configuration using the direct illumination device 3 has been described. However, the present embodiment is not limited to this, and an edge light illumination device having a light guide plate may be used. . Moreover, the illuminating device which has other light sources, such as hot cathode fluorescent tubes other than a cold cathode fluorescent tube, and LED, can also be used.

  The diffusion plate 15 is made of, for example, a rectangular synthetic resin or glass material having a thickness of about 2 mm. The diffusion plate 15 diffuses light from the cold cathode fluorescent tube 20 and emits the light to the optical sheet 17 side. The diffusion plate 15 is mounted on a frame-like surface provided on the upper side of the chassis 12 on the four sides, and the surface of the chassis 12 and the surface of the frame 13 are interposed with an elastically deformable pressing member 16 interposed therebetween. It is incorporated in the lighting device 3 in a state of being held between the inner surface and the inner surface. Further, the diffusion plate 15 is supported at its substantially central portion by a transparent support member (not shown) installed inside the chassis 12, and is prevented from bending inside the chassis 12.

  Further, the diffusion plate 15 is movably held between the chassis 12 and the pressing member 16, and the diffusion plate is affected by heat such as heat generation of the cold cathode fluorescent tube 20 and temperature rise inside the chassis 12. 15, even when expansion (plastic) deformation occurs, the pressing member 16 is elastically deformed so that the plastic deformation is absorbed and the diffusibility of light from the cold cathode fluorescent tube 20 is not reduced as much as possible. Yes. Further, the use of the diffusion plate 15 made of a glass material that is more resistant to heat than the synthetic resin is preferable in that warpage, yellowing, thermal deformation, and the like due to the influence of the heat are less likely to occur.

The optical sheet 17 includes a light collecting sheet made of, for example, a synthetic resin film having a thickness of about 0.5 mm, and is configured to increase the luminance of the illumination light to the liquid crystal panel 2. The optical sheet 17 may be appropriately laminated with known optical sheet materials such as a prism sheet, a diffusion sheet, and a polarizing sheet for improving display quality on the display surface of the liquid crystal panel 2 as necessary. It has become. The optical sheet 17 converts the light emitted from the diffusion plate 15 into planar light having a predetermined luminance (for example, 10000 cd / m ² ) or more and uniform luminance, and is used as illumination light for the liquid crystal panel 2. It is comprised so that it may inject into the side. In addition to the above description, for example, an optical member such as a diffusion sheet for adjusting the viewing angle of the liquid crystal panel 2 may be appropriately stacked above the liquid crystal panel 2 (display surface side).

  Further, in the optical sheet 17, for example, a protruding portion that protrudes to the left in FIG. 1 is formed in the central portion on the left end side in FIG. 1 that is on the upper side when the liquid crystal display device 1 is actually used. In the optical sheet 17, only the protruding portion is sandwiched between the inner surface of the frame 13 and the pressing member 16 with the elastic material 18 interposed therebetween. The optical sheet 17 can be expanded and contracted inside the lighting device 3. Built in state. Thereby, in the optical sheet 17, even when expansion / contraction (plastic) deformation occurs due to the influence of the heat such as the heat generation of the cold cathode fluorescent tube 20, free expansion / contraction deformation based on the protruding portion becomes possible. The optical sheet 17 is configured to prevent wrinkles and deflections from occurring as much as possible. As a result, in the liquid crystal display device 1, it is possible to prevent the display quality of the liquid crystal panel 2 from being deteriorated as much as possible due to the bending of the optical sheet 17 or the like on the display surface of the liquid crystal panel 2.

  Each cold cathode fluorescent tube 20 has a straight tube shape, and electrode portions (not shown) provided at both ends thereof are supported outside the chassis 12. Each of the cold cathode fluorescent tubes 20 is a thin tube having a diameter of about 3.0 to 4.0 mm and excellent in luminous efficiency. Each cold cathode fluorescent tube 20 is a light source holder (not shown). Thus, the distance between each of the diffusion plate 15 and the reflection sheet 19 is held in the chassis 12 in a state where the distance is maintained at a predetermined distance. Further, the cold cathode fluorescent tube 20 is arranged so that its longitudinal direction is parallel to a direction orthogonal to the direction of gravity action. As a result, in the cold cathode fluorescent tube 20, mercury (vapor) enclosed therein is prevented from gathering on one end side in the longitudinal direction due to the action of gravity, and the lamp life is greatly improved. Yes.

  The reflection sheet 19 is made of a metal thin film having a high light reflectance such as aluminum or silver having a thickness of about 0.2 to 0.5 mm, for example, and reflects the light from the cold cathode fluorescent tube 20 toward the diffusion plate 15. To function as a reflector. Thereby, in the illuminating device 3, the light emitted from the cold cathode fluorescent tube 20 can be efficiently reflected to the diffusion plate 15 side, and the use efficiency of the light and the luminance at the diffusion plate 15 can be increased. In addition to this description, a reflective sheet material made of synthetic resin is used in place of the metal thin film, or the inner surface of the chassis 12 is reflected by applying a paint having a high light reflectance such as white. It can also function as a plate.

  Next, with reference to FIG. 2 and FIG. 3 as well, the configuration of the main part of the liquid crystal display device 1 of the present embodiment will be specifically described.

  FIG. 2 is a diagram for explaining a main configuration of the liquid crystal display device, and FIG. 3 is a plan view showing a specific arrangement of source drivers and gate drivers in the liquid crystal display device.

  2 and 3, the liquid crystal display device 1 (FIG. 1) includes a panel control unit 21 that performs drive control of the liquid crystal panel 2 (FIG. 1) as the display unit that displays information such as characters and images, There is provided a temperature detection unit 22 that detects the ambient temperature of the liquid crystal panel 2 and outputs the detection result to the panel control unit 21. In addition, the liquid crystal display device 1 operates based on an instruction signal from the panel control unit 21 serving as a control unit, for example, ten source drivers 23-1, 23-2, ... 23-9, 23-10. (Hereinafter collectively referred to as “23”) and a plurality of, for example, three gate drivers 24-1, 24-2, and 24-3 (hereinafter collectively referred to as “24”).

  The panel control unit 21 is provided in the drive circuit device 10 (FIG. 1), and receives a video signal from the outside of the liquid crystal display device 1. In addition, the panel control unit 21 performs predetermined image processing on the input video signal to generate each instruction signal to the source driver 23 and the gate driver 24, and the input video signal. A frame buffer 21b capable of storing display data for one frame included. The panel control unit 21 performs drive control of the source driver 23 and the gate driver 24 according to the input video signal, so that information corresponding to the video signal is displayed on the liquid crystal panel 2.

  A temperature sensor is used for the temperature detection unit 22, detects the ambient temperature of the liquid crystal panel 2, and outputs the detected temperature data (detection result) to the panel control unit 21. And in the panel control part 21, using the detection result from the temperature detection part 22, the source drivers 23-1 to 23-5 and 23- provided on the upper side and the lower side of the effective display area A of the liquid crystal panel 2, respectively. The source signal (data signal) output from 6 to 23-10 is limited (details will be described later).

  The source driver 23 and the gate driver 24 are installed on the active matrix substrate 5. Specifically, as shown in FIG. 3, the source drivers 23-1 to 23-5 are arranged on the surface of the active matrix substrate 5 in the outer region above the effective display region A of the liquid crystal panel 2. It is installed in a straight line along the horizontal direction. Further, the source drivers 23-6 to 23-10 are located below the effective display area A of the liquid crystal panel 2 on the surface of the active matrix substrate 5 so as to face the source drivers 23-1 to 23-5, respectively. It is installed in a straight line along the lateral direction of the liquid crystal panel 2 in the outer region. These source drivers 23-1 to 23-5 and 23-6 to 23-10 are arranged above and below the direction of gravity when the liquid crystal display device 1 is used, respectively. Yes.

  Further, the gate drivers 24-1 to 24-3 are linearly arranged on the surface of the active matrix substrate 5 so as to be along the vertical direction of the liquid crystal panel 2 in the outer area of the effective display area A.

  The source driver 23 and the gate driver 24 are drive circuits that drive a plurality of pixels P provided in the liquid crystal panel 2 in units of pixels. The source driver 23 and the gate driver 24 include a plurality of source lines S1 to SM. (M is an integer of 10 or more, hereinafter collectively referred to as “S”) and a plurality of gate wirings G1 to GN (N is an integer of 3 or more, and hereinafter collectively referred to as “N”). It is connected. In each source driver 23-1 to 23-10, the same number of source wirings (data wirings) S are connected, and the source drivers 23-1 to 23-5 and 23-6 to 23-10 are respectively First and second data wiring drive circuits are configured. In each of the gate drivers 24-1 to 24-3, the same number of gate wirings (scanning wirings) G are connected, and the gate drivers 24-1 to 24-3 constitute a scanning wiring driving circuit. .

  Specifically, one end side of (M / 5) source lines S is connected to each source driver 23-1 to 23-5, and each source driver 23-6 to 23-10 is connected to each source driver 23-1 to 23-5. The other end side of the (M / 5) source lines S is connected. The source drivers 23-1 to 23-5 and 23-6 to 23-10 are connected to one end side and the other end side of the same source wiring S, respectively, and in accordance with an instruction signal from the panel control unit 21, liquid crystal Source signals (data signals) corresponding to information displayed on the panel 2 can be output simultaneously. Further, (N / 3) gate wiring lines G are connected to the gate drivers 24-1 to 24-3, and the gate drivers 24-1 to 24-3 are connected in a predetermined scanning direction (for example, the liquid crystal panel 2). The scanning operation is performed by sequentially outputting gate signals (scanning signals) along the direction from the upper side to the lower side of the signal.

  The source lines S and the gate lines G are arranged in a matrix form at least in the effective display area A, and the areas of the plurality of pixels P are formed in the areas partitioned in the matrix form. ing. More specifically, as illustrated in FIG. 2, the source wiring S includes source wiring main body portions S1b, S2b, S3b,... Arranged in parallel to the vertical direction of the liquid crystal panel 2, and these source wiring main body portions. Connection wires S1a, S2a, S3a,... That connect the source drivers 23-1 to 23-5 corresponding to S1b, S2b, S3b,. Further, the source wiring S is connected to a source wiring main body S1b, S2b, S3b,... Corresponding to the source drivers 23-6 to 23-10 so that the distance is not as long as possible (not shown). It is included.

  Similarly, the gate wiring G includes gate wiring main body portions G1b, G2b,... Arranged in parallel to the horizontal direction of the liquid crystal panel 2, and gate drivers 24-1 corresponding to these gate wiring main body portions G1b, G2b,. To 24-6 so as to prevent the distance from becoming as long as possible.

  The plurality of pixels P include red, green, and blue pixels. Further, these red, green, and blue pixels are sequentially arranged in parallel with the gate wiring main body portions G1b, g2b,.

  Further, the gate of the switching element 25 provided for each pixel P is connected to the gate wiring main body portions G1b, g2b,. On the other hand, the source of the switching element 25 is connected to the source wiring body portions S1b, S2b, S3b,. A pixel electrode 26 provided for each pixel P is connected to the drain of each switching element 25. In each pixel P, the common electrode 27 is configured to face the pixel electrode 26 with the liquid crystal layer 4 (FIG. 1) provided on the liquid crystal panel 2 interposed therebetween. The gate driver 24 sequentially outputs gate signals for turning on the gates of the corresponding switching elements 25 to the gate lines G1 to GN based on the instruction signal from the image processing unit 21a. On the other hand, the source driver 23 outputs a source signal (gradation voltage) corresponding to the luminance (gradation) of the display image to the corresponding source lines S1 to SM based on the instruction signal from the image processing unit 21a.

  Here, the operation of the liquid crystal display device 1 configured as described above will be specifically described with reference to FIGS. In the following description, the operation in which the source driver 23 outputs the source signal to the source line S according to the instruction signal from the panel control unit 21 will be mainly described.

  FIG. 4 is a block diagram showing a main configuration of the source driver. FIG. 5 is a diagram for explaining an operation example of the source driver in the liquid crystal display device, and FIG. 6 is a diagram for explaining another operation example of the source driver in the liquid crystal display device.

  First, with reference to FIG. 4, the configuration of the main part of the source driver 23 and its basic operation will be described.

  As illustrated in FIG. 4, the source driver 23 includes a shift register 23a, a sampling memory 23b, a hold memory 23c, a level shifter 23d, a DA converter 23e, and an output circuit 23f that are sequentially connected to the shift register 23a. The source signal is output to the source line S connected to the output circuit 23f.

  The shift register 23a performs a shift operation based on an instruction signal from the panel control unit 21 to select data to be output to the connected source wiring S with respect to the data of the video signal from the outside. The sampling memory 23b samples and stores data selected by the shift register 23a from a data latch (not shown).

  The hold memory 23c collectively latches and stores the data stored in the sampling memory 23b based on the instruction signal from the panel control unit 21. The level shifter 23d shifts the data stored in the hold memory 23c to a predetermined level and outputs it to the DA converter 23e.

  The DA converter 23e converts the data from the level shifter 23d into an analog signal and outputs the analog signal to the output circuit 23f. The output circuit 23f uses a voltage follower having an operational amplifier ejection force buffer, and outputs a corresponding analog signal from the DA converter 23e to each of the connected (M / 5) source lines S. . Thereby, a source signal corresponding to information to be displayed on the corresponding pixel of the liquid crystal panel 2 is supplied. In addition, a three-state buffer is used as the output buffer, and the output of the analog signal (source signal) to the source line S can be appropriately stopped according to the instruction signal from the panel control unit 21.

  Next, the output operation of the source signal from the source driver 23 to the source line S will be specifically described with reference to FIGS.

  In FIG. 5, when the detection result from the temperature detection unit 22 is notified that the detection result is lower than the first threshold temperature (for example, lower than 5 ° C.), the panel control unit 21 causes the upper source drivers 23-1 to 23-. 5 and lower source drivers 23-6 to 23-10 are driven at the same time, the source drivers 23-1 to 23-5 and 23-6 to 23-10 are damaged due to heat generated by an increase in load. It is determined that there is no abnormality such as. Therefore, as shown in FIG. 5A, the panel control unit 21 supplies the source wiring S from the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10. Output the source signal.

  Specifically, for example, in the source driver 23-1, as shown in FIGS. 5B and 5C, the output timing of the source signal to the source wiring S1 is set at the time T1 to T2, and the time At T1, the source signal is output to one end side of the source line S1. Thereafter, in the source driver 23-1, the output timing of the source signal to the source line S2 is set at time points T3 to T4, and after the source signal is output to one end side of the source line S2 at time point T3, the time points T5 to T6. , The output timing of the source signal to the source line S3 is set, and at time T5, the source signal is output to one end side of the source line S3.

  Then, in the source driver 23-1, the output timing of the source signal to the source line S4 is set at the time T7 to T8, and after the source signal is output to one end side of the source line S4 at the time T7, the time T9 to T10. , The output timing of the source signal to the source line S5 is set, and at time T9, the source signal is output to one end side of the source line S5.

  Note that, at a timing when the source signal is not output, for example, between time points T2 and T3, the panel control unit 21 changes the state of the three-state buffer in the output buffer to a high impedance state in order to stop the output of the source signal. In this state, the source signal is prevented from being output to the source line S.

  Further, in the source driver 23-6 to which the same source wiring S as the source driver 23-1 is connected, as shown in FIGS. 5D and 5E, the source driver S1 is connected to the source wiring S1 at time points T1 to T2. The output timing of the source signal is set, and at time T1, the source signal is output to the other end side of the source wiring S1. Thereafter, in the source driver 23-6, the output timing of the source signal to the source line S2 is set at time points T3 to T4, and after the source signal is output to the other end side of the source line S2 at time point T3, At T6, the output timing of the source signal to the source line S3 is set, and at time T5, the source signal is output to the other end side of the source line S3.

  Then, in the source driver 23-6, the output timing of the source signal to the source line S4 is set at the time T7 to T8, and after the source signal is output to the other end side of the source line S4 at the time T7, the time T9 to At T10, the output timing of the source signal to the source line S5 is set, and at time T9, the source signal is output to the other end side of the source line S5.

  Further, when the detection result from the temperature detection unit 22 is lower than the first threshold temperature, both the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10 are used. Since the source signal is supplied from the source line S to the source line S, the source voltage can be appropriately charged in each pixel even at a low temperature when the liquid crystal layer 4 is relatively difficult to be charged.

  In addition, in FIG. 6, when notified from the temperature detection unit 22 that the detection result is equal to or higher than the first threshold temperature, the panel control unit 21 displays the upper source drivers 23-1 to 23-5 and the lower side driver. When both of the source drivers 23-6 to 23-10 are driven at the same time, the source drivers 23-1 to 23-5 and 23-6 to 23-10 may be abnormal due to heat generation due to an increase in load. Judge that there is. Therefore, as illustrated in FIGS. 6A to 6E, the panel control unit 21 includes the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10. Are alternately intermittently operated, and source signals are output from the source drivers 23-1 to 23-5 and 23-6 to 23-10 to the source wiring S.

  Specifically, for example, in the source driver 23-1, as shown in FIGS. 6B and 6C, the output timing of the source signal to the source line S1 is set at the time T11 to T12, and the time At T11, the source signal is output to one end side of the source line S1. Thereafter, in the source driver 23-6, as shown in FIG. 6D and FIG. 6E, the output timing of the source signal to the source line S2 is set from time T13 to time T14, and the source signal is output at time T13. It is output to the other end side of the source wiring S2.

  Subsequently, in the source driver 23-1, as shown in FIG. 6B and FIG. 6C, the output timing of the source signal to the source line S3 is set at time T15 to T16, and the source signal at time T15. Is output to one end of the source line S3. Thereafter, in the source driver 23-6, as shown in FIG. 6D and FIG. 6E, the output timing of the source signal to the source line S4 is set from time T17 to T18, and the source signal is output at time T17. It is output to the other end side of the source wiring S4.

  Then, in the source driver 23-1, as shown in FIGS. 6B and 6C, the output timing of the source signal to the source line S5 is set from time T19 to T20, and the source signal is output at time T19. It is output to one end side of the source wiring S5.

  As described above, when the detection result from the temperature detection unit 22 is equal to or higher than the first threshold temperature, the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10 are alternately arranged. In intermittent operation, the source signal is supplied to the source line S, and the liquid crystal layer 4 is charged with the source voltage in each pixel.

  In the liquid crystal display device 1 of the present embodiment configured as described above, upper and lower source drivers (first and second data line driving circuits) on one end side and the other end side of the source line (data line) S. ) 23-1 to 23-5 and 23-6 to 23-10 are connected, and the source signal (data signal) is supplied to the source line S from the source drivers 23-1 to 23-5 and 23-6 to 23-6. 23-10 is input. Further, in the liquid crystal display device 1 of the present embodiment, the temperature detection unit 22 that detects the ambient temperature of the liquid crystal panel (display unit) 2 is provided, and the panel control unit (control unit) 21 detects the detection result of the temperature detection unit 22. Is used to limit the source signal output to the source line S from at least one of the source drivers 23-1 to 23-5 and 23-6 to 23-10. As a result, in the liquid crystal display device 1 of the present embodiment, unlike the conventional example, even when the screen of the liquid crystal panel 2 is increased, the load on the source driver 23 is prevented from increasing, and the tolerance of the source driver 23 is allowed. It is possible to reliably prevent the operating temperature from being exceeded. As a result, in the present embodiment, the liquid crystal display device 1 having excellent reliability can be easily configured.

  Further, in the liquid crystal display device 1 of the present embodiment, when the panel control unit 21 determines that the detection result from the temperature detection unit 22 is equal to or higher than the first threshold temperature, the upper source drivers 23-1 to 23- 5 and the lower source drivers 23-6 to 23-10 are alternately operated intermittently. Thereby, in the liquid crystal display device 1 of the present embodiment, the loads of the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10 can be appropriately distributed. Heat generation in the drivers 23-1 to 23-10 can be reliably suppressed.

  Further, in the liquid crystal display device 1 of the present embodiment, as shown in FIGS. 5 and 6, the panel control unit 21 uses the detection result from the temperature detection unit 22, and the upper source drivers 23-1 to 23-. 5 and the lower source drivers 23-6 to 23-10 are changed, the panel control unit 21 can appropriately operate the liquid crystal layer 4 according to the detection result.

  In the above description, the case where the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10 are intermittently operated alternately has been described as an example. However, the liquid crystal display device 1 is not limited to this. That is, in the liquid crystal display device 1 according to the present embodiment, when the panel control unit 21 determines that the detection result from the temperature detection unit 22 is equal to or higher than the first threshold temperature, the panel control unit 21 detects the upper source driver 23. -1 to 23-5 and upper source drivers 23-1 to 23-23 with respect to a predetermined number of source lines S among the plurality of source lines S connected to the lower source drivers 23-6 to 23-10. -5 and one of the lower source drivers 23-6 to 23-10 are output, and the upper source drivers 23-1 to 23-5 and the lower source drivers S A source signal may be output from the other of the source drivers 23-6 to 23-10.

[Second Embodiment]
FIG. 7 is a diagram for explaining a main configuration of a liquid crystal display device according to the second embodiment of the present invention. In the figure, the main difference between this embodiment and the first embodiment is that when the panel control unit determines that the detection result from the temperature detection unit is equal to or higher than the second threshold temperature, the panel control unit Is that a source signal is output to the source wiring from only one of the upper source driver and the lower source driver. In addition, about the element which is common in the said 1st Embodiment, the same code | symbol is attached | subjected and the duplicate description is abbreviate | omitted.

  That is, as shown in FIG. 6, in the liquid crystal display device 1 of the present embodiment, a panel control unit 21 'is provided. In the panel control unit 21 ′, as in the case of the first embodiment, an image that performs predetermined image processing on the input video signal and generates each instruction signal to the source driver 23 and the gate driver 24. A processing unit 21a ′ and a frame buffer 21b ′ capable of storing display data for one frame included in the input video signal are provided.

  In addition, when the detection result from the temperature detection unit 22 is less than the second threshold temperature (for example, less than 5 ° C.), the panel control unit 21 ′ is similar to that of the first embodiment in FIG. As illustrated, both the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10 are simultaneously driven to output source signals to the source line S.

  On the other hand, when the detection result from the temperature detection unit 22 is equal to or higher than the second threshold temperature, the panel control unit 21 ′ uses the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23. −10, source signals are output to the source line S only from the lower source drivers 23-6 to 23-10 provided on the lower side of the gravity direction.

  Here, with reference to FIG. 8, the operation of the liquid crystal display device 1 of the present embodiment configured as described above will be specifically described. In the following description, the operation of the panel control unit 21 ′ when the detection result of the temperature detection unit 22 is equal to or higher than the second threshold temperature will be mainly described.

  FIG. 8 is a diagram for explaining an operation example of the source driver in the liquid crystal display device shown in FIG.

  In FIG. 8, when the detection result from the temperature detection unit 22 is notified that the detection result is equal to or higher than the second threshold temperature, the panel control unit 21 ′ displays the upper source drivers 23-1 to 23-5 and the lower source source. When both of the drivers 23-6 to 23-10 are driven at the same time, the source drivers 23-1 to 23-5 and 23-6 to 23-10 may be abnormal due to heat generation due to an increase in load. Judge that there is. Therefore, as illustrated in FIGS. 8A to 8E, the panel control unit 21 ′ stops driving the upper source drivers 23-1 to 23-5 and lowers the source. Source signals are output to the source line S only from the drivers 23-6 to 23-10.

  More specifically, as shown in FIG. 8B, the panel control unit 21 ′, for example, in order to stop the output of the source signal in the source driver 23-1, the three-state buffer in the output buffer. Is set to a high impedance state. As a result, as shown in FIG. 8C, the source driver 23-1 does not output a source signal.

  On the other hand, for example, in the source driver 23-6, as shown in FIG. 8D and FIG. 8E, the output timing of the source signal to the source line S1 is set at time T21 to T22, and the source signal at time T21. Is output to the other end of the source line S1. Thereafter, the source driver 23-6 sets the output timing of the source signal to the source line S2 at time points T23 to T24, and after the source signal is output to the other end side of the source line S2 at time point T23, At T26, the output timing of the source signal to the source line S3 is set, and at time T25, the source signal is output to the other end side of the source line S3.

  Then, in the source driver 23-6, the output timing of the source signal to the source line S4 is set at time T27 to T28, and after the source signal is output to the other end side of the source line S4 at time T27, At T30, the output timing of the source signal to the source line S5 is set, and at time T29, the source signal is output to the other end side of the source line S5.

  With the above configuration, the present embodiment can achieve the same operations and effects as the first embodiment. In the liquid crystal display device 1 of the present embodiment, when the panel control unit 21 ′ determines that the detection result from the temperature detection unit 22 is equal to or higher than the second threshold temperature, the upper source drivers 23-1 to 23-23. −5 and the lower source drivers 23-6 to 23-10, source signals are sent from only the lower source drivers 23-6 to 23-10 provided on the lower side in the direction of gravity. Is output. Thereby, in this embodiment, the power consumption of the liquid crystal display device 1 can be reduced. Further, among the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10, the upper source drivers 23-1 to 23-5 having a high ambient temperature are stopped. It is possible to easily prevent the upper source drivers 23-1 to 23-5 and the lower source drivers 23-6 to 23-10 from malfunctioning due to the ambient temperature and heat generated by driving. it can.

  In the above description, the case where the second threshold temperature is set to the same temperature as the first threshold temperature is described as an example. However, the liquid crystal display device 1 of the present embodiment is not limited to this, A temperature different from the first threshold temperature may be set as the second threshold temperature. In addition to the above description, the first and second embodiments may be combined. In other words, the panel control unit may perform driving control of the upper and lower source drivers using the first and second threshold temperatures different from each other.

  The above embodiments are all illustrative and not restrictive. The technical scope of the present invention is defined by the claims, and all modifications within the scope equivalent to the configurations described therein are also included in the technical scope of the present invention.

  For example, in the above description, the case where the present invention is applied to a transmissive liquid crystal display device has been described. However, the display device of the present invention is not limited to this, and a transflective or reflective liquid crystal display device. Or it can apply to various display apparatuses, such as an organic EL (Electronic Luminescence) element, an inorganic EL element, and a field emission display.

  In the above description, the case where five upper and lower source drivers (first and second data wiring driving circuits) are provided for M source wirings (data wirings) has been described. Is connected to one end side and the other end side of the data wiring, respectively, and outputs first and second data wiring driving circuits for outputting data signals according to information displayed on the display unit, and the ambient temperature of the display unit. A temperature detecting unit for detecting, and the control unit uses the detection result of the temperature detecting unit to limit a data signal output to the data wiring from at least one of the first and second data wiring driving circuits. The number of installed data lines and the number of connected data lines and the first and second data line drive circuits are not limited to the above.

  However, in the case where a plurality of sets of first and second data wiring drive circuits are provided as in the above-described embodiments, the plurality of sets of the first and second sets can be provided even when the display section is enlarged. This is preferable in that the load on each data wiring drive circuit 2 can be reliably reduced.

  The present invention is useful for a display device with excellent reliability capable of preventing an increase in the load on the data wiring drive circuit even when the screen of the display unit is enlarged.

It is a schematic sectional drawing explaining the liquid crystal display device concerning the 1st Embodiment of this invention. It is a figure explaining the principal part structure of the said liquid crystal display device. It is a top view which shows the specific arrangement | positioning of the source driver and gate driver in the said liquid crystal display device. It is a block diagram which shows the principal part structure of the said source driver. It is a figure explaining the operation example of the source driver in the said liquid crystal display device. It is a figure explaining another example of operation of a source driver in the above-mentioned liquid crystal display. It is a figure explaining the principal part structure of the liquid crystal display device concerning the 2nd Embodiment of this invention. It is a figure explaining the operation example of the source driver in the liquid crystal display device shown in FIG.

Explanation of symbols

1 Liquid crystal display device (display device)
2 Liquid crystal panel (display unit)
21, 21 'Panel control unit (control unit)
22 temperature detector 23-1 to 23-5 source driver (first data wiring drive circuit)
23-6 to 23-10 Source driver (second data line driving circuit)
S1 to SM source wiring (data wiring)
G1 to GN Gate wiring (scanning wiring)
P pixel

Claims (6)

A display device including a plurality of data lines and a plurality of scan lines arranged in a matrix and a plurality of pixels provided in the vicinity of an intersection of the data lines and the scan lines in a display unit,
A first data line driving circuit connected to one end of the data line and outputting a data signal corresponding to information displayed on the display unit;
A second data line driving circuit connected to the other end of the data line and outputting a data signal corresponding to information displayed on the display unit;
A temperature detection unit for detecting the ambient temperature of the display unit;
A control unit for controlling the driving of the first and second data line driving circuits;
The control unit limits a data signal output to the data line from at least one of the first and second data line driving circuits using a detection result of the temperature detection unit.
A display device characterized by that. The display device according to claim 1, wherein a plurality of sets of the first and second data line driving circuits are provided. When the control unit determines that the detection result from the temperature detection unit is equal to or higher than a first threshold temperature, the control unit transmits the plurality of data connected to the first and second data line driving circuits. Among the wirings, a data signal is output from one of the first and second data wiring driving circuits to a predetermined number of data wirings, and the first and second data wirings are output to the remaining data wirings. The display device according to claim 1, wherein a data signal is output from the other of the data line driving circuits. When the control unit determines that the detection result from the temperature detection unit is equal to or higher than the second threshold temperature, the control unit selects either one of the first and second data wiring drive circuits. The display device according to claim 1, wherein a data signal is output to the data wiring only from a wiring driving circuit. 5. The display device according to claim 4, wherein one of the data line driving circuits is provided on a lower side of the first and second data line driving circuits in the direction of action of gravity. The display device according to claim 1, wherein the display unit includes a liquid crystal panel including a pair of transparent substrates and a liquid crystal layer sandwiched between the pair of transparent substrates.

Images