JP4094536B2 - Display device - Google Patents

Description

  The present invention relates to a display device that employs a matrix type display unit using a display element having a large temperature dependency.

  In recent years, moving images have been projected on a liquid crystal display device that has been used as a display device for computers. This phenomenon is due to the development of models for TV applications in liquid crystal display devices as the size of liquid crystal display devices has increased, and the use of moving images on computers as the performance of computers has improved. is there.

  Here, the major problem with projecting moving images on the liquid crystal module is the slow response speed of the liquid crystal display device. That is, when a moving image is projected on a display device with a slow response speed, an afterimage remains and the display quality is impaired. In particular, in a liquid crystal display device, the response speed between halftone and halftone is further slower than the monochrome response speed, and when a natural image is handled, the display quality of the specific moving image is significantly deteriorated.

  Therefore, as a method for improving the response speed of the liquid crystal, for example, as shown in Patent Document 1, driving methods called overshoot driving and overdrive driving are applied. These driving methods improve response speed by applying a change equal to or greater than the change of input data to the liquid crystal module.

  By the way, in the liquid crystal display device, the temperature in the liquid crystal panel is affected by the ambient environment temperature and also varies during the display operation of the liquid crystal panel. Therefore, the response speed cannot be improved properly unless a change equal to or greater than the change in the input data corresponding to the temperature in the liquid crystal panel is applied, resulting in poor display quality during video display. Will do.

  Therefore, conventionally, for example, in the liquid crystal display device disclosed in Patent Document 2, as shown in FIG. 10, temperature sensors Th1 to Th8 are attached to the periphery of the liquid crystal panel 101, and the temperature of the liquid crystal panel 101 is set to these temperature sensors. By measuring Th1-Th8 and changing the applied voltage to the antiferroelectric liquid crystal based on the measured temperature, the entire luminance variation of the liquid crystal panel 101 due to temperature is corrected.

  Specifically, in this liquid crystal display device, as one method, as a means for correcting a temperature change in the liquid crystal panel 101, the temperature around the liquid crystal panel 101 is measured and an average value thereof is calculated. The temperature of the panel 101 is estimated, and the pulse widths of the scanning voltage and the signal voltage are changed based on the estimated temperatures, so that the response characteristics of the liquid crystal panel correspond to the temperature change. As another method, by measuring the ambient temperature of the liquid crystal panel 101, as shown in FIG. 11, the temperature distribution of each region in four regions obtained by dividing the liquid crystal panel 101 into four regions is estimated, and the estimation is performed. The response characteristics of the liquid crystal panel are made to correspond to the temperature change by changing the pulse widths of the scanning voltage and the signal voltage for each region based on the respective temperatures.

  However, in the liquid crystal display device described above, the temperature change is such that the ambient temperature of the liquid crystal panel 101 is measured, the temperature of the display surface in the liquid crystal panel 101 is estimated, and correction is made every four regions based on the estimated temperature. The correction for is only roughly performed along the estimated temperature, which is the ambient temperature. Therefore, even if it is divided into the four regions, there is a problem that accurate temperature compensation cannot be performed as the drive voltage.

  In order to solve this problem, in the liquid crystal display device disclosed in Patent Document 3, temperature sensors 202a to 202d are provided around the liquid crystal panel 201 as shown in FIG. A temperature sensor 203 for detecting the temperature of one display region position is provided, and the temperature for each predetermined pixel region of the liquid crystal panel 201 is estimated based on the temperature detected by the temperature sensor 203 and the temperature sensors 202a to 202d. Based on the estimated temperature, the actual intensity of the image data signal is corrected so as to become the target intensity at the predetermined temperature of the liquid crystal panel 201 for each predetermined pixel region. A signal voltage is generated based on the corrected image data signal by this correction.

As described above, by providing at least one temperature sensor 203 also in the display area in the liquid crystal panel 201, the luminance of the liquid crystal panel 201 is finely corrected for each predetermined pixel area, so that the temperature distribution of the liquid crystal panel 201 varies. Even if there is, the display surface of the liquid crystal panel 201 is always satisfactorily maintained at the above-mentioned luminance at the predetermined temperature without being affected by this. As a result, the image data signal of the liquid crystal panel can be controlled without being affected by the temperature change on the display surface of the liquid crystal panel.
Japanese Patent Publication No. 63-25556 (published May 25, 1988) Japanese Patent No. 2507713 (issued June 19, 1996) JP 2000-81607 A (published March 21, 2000) Satoshi Mano (Shizuoka Prefectural Industrial Technology Center), Hirohisa Masui (Shizuoka Prefectural Industrial Technology Center), 14 others, “Research on the development of non-contact temperature sensors using infrared rays”, [Online], “Safety sensing technology for automobiles Research and development: Subsidy for R & D expenses for regional activation creation technology for 2000-2014 (Text for announcement of results of SME technology development industry-academia-government collaboration promotion project), [Search July 30, 2003], Internet <URL : http: //www.f-iri.pref.shizuoka.jp/publish/monodukuri.htm,http: //www.f-iri.pref.shizuoka.jp/publish/Chapter2.pdf>

  However, it is considered that the temperature sensor 203 provided at the center position of the liquid crystal panel 201 in the liquid crystal display device disclosed in Patent Document 3 is actually composed of a thermocouple provided on the back side of the liquid crystal panel. That is, the provision of the temperature sensor 203 in the display area disturbs the display, so that it cannot be actually provided on the surface of the liquid crystal panel 201.

  Therefore, even in the technique disclosed in Patent Document 3, since the actual temperature of the display element is not measured, only the pulse width of the scanning voltage and the signal voltage can be changed by the approximate temperature based on the estimated temperature. Has a problem.

  In this problem, since the response speed is improved for each pixel by overshoot driving, the temperature management of the liquid crystal element is important in controlling the correction voltage.

  The present invention has been made in view of the above-described conventional problems, and its object is to grasp the temperature of a display element provided in an actual pixel, improve response speed, and improve display quality. It is to provide a display device.

  In order to solve the above problems, the display device of the present invention is provided at intersections of a plurality of scanning signal lines, a plurality of data signal lines to which video signals are supplied as data signals, and the scanning signal lines and the data signal lines. Correspondingly, in a display device having a display unit in which pixels connected via a switch unit are arranged in a matrix, a temperature sensor provided in at least one pixel in a display region of the display unit, and the temperature A lead wire embedded in the display unit for guiding a detection signal from the sensor to the periphery of the display unit, a temperature detection control unit for detecting a temperature based on the detection signal from the temperature sensor, and a temperature detection control unit from the temperature detection control unit Data signal line driving means for outputting a data signal to the data signal line based on the temperature in the pixel is provided.

  According to the above invention, the display device is provided with the temperature sensor in at least one pixel in the display area of the display unit. A detection signal from the temperature sensor is guided to the periphery of the display unit by a lead wire embedded in the display unit.

  A temperature detection control unit is provided around the display unit, and the temperature detection control unit detects the temperature based on a detection signal from the temperature sensor. The data signal line driving means outputs a data signal to the data signal line based on the temperature in the pixel from the temperature detection control means.

  Therefore, the actual temperature in the pixel is reflected in the data signal to the data signal line. Therefore, gradation control based on the actual temperature of the display element, not the estimated temperature, can be performed for the response speed that is easily affected by temperature changes, so that the display area of the display unit is based on an appropriate response speed. Display is performed.

  Therefore, it is possible to provide a display device that can grasp the temperature of a display element provided in an actual pixel, improve response speed, and improve display quality.

  In the display device according to the present invention, in each of the display devices described above, each data signal line is provided with a ladder-shaped spare wiring for avoiding data signal disconnection due to disconnection of the data signal line. The spare wiring is used as the lead wire.

  The display device of the present invention is characterized in that, in the display device described above, the temperature sensor is a thermistor type sensor formed by forming an element film in a pixel formation process.

  According to the above invention, the temperature sensor is formed by sequentially forming the element films in the pixel forming process. As a result, the temperature sensor is completed by manufacturing the display device. For this reason, manufacture of a temperature sensor is easy. In addition, the temperature sensor is a thermistor type sensor built in the pixel formation process, so that it can be formed as a thin film and is compact. Therefore, even if it exists inside the display element, display is not hindered. Further, since the temperature sensor is a thermistor type sensor, the power consumption is low. Therefore, it is suitable as a temperature sensor for a display device.

  According to the display device of the invention, in the display device described above, the data signal line driving unit supplies a data signal voltage higher than the data signal voltage corresponding to the gradation value indicated by the video signal to the data signal line. It is characterized by that.

  According to the above invention, the data signal line driving means supplies a data signal voltage larger than the data signal voltage corresponding to the gradation value indicated by the video signal to the data signal line. That is, overshoot drive is adopted.

  Therefore, since overshoot driving is easily affected by temperature, it is necessary to grasp the pixel temperature. Therefore, the effect of providing the temperature sensor in the pixel is great.

  The display device of the present invention is characterized in that in the display device described above, the temperature sensor is provided in the vicinity of the scanning signal line or the data signal line.

  According to the above invention, since the shielding member is usually provided in the vicinity of the scanning signal line or the data signal line, the temperature sensor can be hidden. In addition, when a temperature sensor is provided at the center of the pixel, it is necessary to provide a shielding member in order to prevent the temperature sensor from being seen. However, the aperture ratio decreases. However, in the present invention, since the temperature sensor is provided in the vicinity of the scanning signal line or the data signal line, the aperture ratio does not decrease.

  The display device of the present invention is characterized in that, in the display device described above, the temperature sensor is shielded by a shielding member.

  According to the above invention, since the temperature sensor is shielded by the shielding member, the temperature sensor can be surely hidden.

  Further, in the display device according to the present invention, in the display device described above, when the height of the display area of the display unit is H, the temperature sensor is respectively configured from the upper and lower ends in the display area to H / 4. In addition to being provided in a plurality of pixels, the temperature detection control means averages the detection signals from the plurality of temperature sensors to obtain an in-pixel temperature.

  According to the above invention, the temperature sensor is provided in a plurality of pixels excluding the upper and lower ends and H / 4 in the display area. Therefore, a display area having a small temperature change can be excluded from measurement.

  The temperature detection control means averages the detection signals from the plurality of temperature sensors to obtain the temperature within the pixel. Therefore, it is possible to obtain the pixel temperature reflecting the entire display region where the temperature change in the display unit is large.

  The display device according to the present invention is the display device described above, wherein the temperature sensors are two-dimensionally scattered in the display area, and the projection horizontal intervals of the temperature sensors are set to be equal to each other. It is characterized by being.

  According to the above invention, since the projection horizontal intervals of the temperature sensors scattered two-dimensionally in the display area are set to be equal to each other, the pixel temperature that uniformly reflects the horizontal direction of the display unit is obtained. be able to.

  The display device of the present invention is characterized in that, in the display device described above, the intervals of the data signal lines in the display region where the temperature sensor is arranged are equal.

  According to the above invention, since the intervals of the data signal lines are equal, it is possible to reliably obtain the pixel temperature that reflects the horizontal direction of the display unit evenly.

  The display device of the present invention is characterized in that, in the display device described above, the distances between the temperature sensors in the vertical direction in the display area are equal to each other.

  According to the above invention, the distance between the temperature sensors in the vertical direction within the display area is also equal to each other, and the temperature distribution can be obtained two-dimensionally and uniformly.

  In the display device of the present invention, a temperature sensor is provided in at least one pixel in the display area of the display unit, and a detection signal thereof is guided to the periphery of the display unit by a lead wire embedded in the display unit. A data signal is output to the data signal line based on the temperature in the pixel by temperature detection based on the temperature sensor.

  Therefore, the actual temperature in the pixel is reflected in the data signal to the data signal line. Therefore, gradation control based on the actual temperature of the display element, not the estimated temperature, can be performed for the response speed that is easily affected by temperature changes, so that the display area of the display unit is based on an appropriate response speed. Display is performed.

  Therefore, it is possible to provide a display device that can grasp the temperature of the display element provided in the actual pixel, improve the response speed, and improve the display quality.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 9 as follows.

  As shown in FIG. 2, a liquid crystal display device 1 as an active matrix display device according to the present embodiment includes a display panel 2 as a display unit, a scanning signal line driving unit 3 that outputs a scanning signal, and a video signal. It comprises a data signal line driving unit 4 as data signal line driving means for applying a certain data signal. The display panel 2 includes, for example, a pair of upper and lower glass substrates parallel to each other, a polarizing plate formed on the outer surfaces of both glass substrates, and a transparent electrode formed on the inner surfaces of the glass substrates. An alignment film formed on the transparent electrode, a sealing resin that hermetically seals the outer peripheral portions of both glass substrates, and a liquid crystal sealed in a space formed by the glass substrate and the sealing resin. Yes.

  For example, the transparent electrodes are formed in common on the upper substrate, whereas, on the lower substrate, the transparent electrodes are arranged in a matrix corresponding to each pixel.

  On the lower substrate, a large number of data signal lines 5 parallel to one direction and a large number of scanning signal lines 6 orthogonal to the data signal lines 5 are provided in parallel. The data signal line 5 and the scanning signal line 6 intersect with each other in an electrically insulated state. In each region surrounded by the data signal line 5 and the scanning signal line 6, a pixel electrode 7 is provided. The pixel electrode 7 is connected to a TFT (Thin Film Transistor) 8 serving as a switching unit.

  The data signal line 5 is connected to the data signal line driving unit 4 through a signal line terminal 5a, and a data signal is applied to the data signal line 5. On the other hand, the scanning signal line 6 is connected to the scanning signal line driving unit 3 through a scanning line terminal 6a, and a scanning signal is applied to the scanning signal line 6.

  As shown in FIG. 3, the TFT 8 has a gate electrode 9, a gate insulating film 22, a semiconductor layer 23, a channel protective layer 24, a source electrode 10, and an n + -Si layer serving as the drain electrode 11 on a glass substrate 21. It has the structure laminated | stacked in this order. The gate electrode 9 of the TFT 8 is connected to the scanning signal line 6 and the source electrode 10 is connected to the data signal line 5 as shown in FIG. Further, as shown in FIG. 3, the drain electrode 11 is connected to the connection electrode 25, and is connected to the pixel electrode 7 through the connection electrode 25.

  The pixel electrode 7 is arranged in a region surrounded by the adjacent data signal line 5 and the adjacent scanning signal line 6. The pixel electrode 7 is provided with an interlayer insulating film 26 between the TFT 8, the scanning signal line 6, and the data signal line 5, so that the peripheral ends thereof are the data signal line 5 and the scanning signal line. It overlaps with 6. The pixel electrode 7 and the connection electrode 25 are connected through a contact hole 27 formed in the interlayer insulating film 26.

  Further, on the glass substrate 21, the auxiliary capacitance wiring 13 is arranged in parallel with the scanning wiring 1 and between the adjacent scanning signal lines 6. The auxiliary capacitance line 13 is provided in common for all the pixel electrodes 7. Further, the auxiliary capacitor 12 is formed between the auxiliary capacitor line 13 and the contact hole 27.

  As shown in FIG. 2, all the auxiliary capacitance lines 13 are short-circuited, and are connected to the lower substrate via auxiliary capacitance line terminals 13a.

  In the active matrix type liquid crystal display device 1 configured as described above, ON / OFF of the TFT 8 on each scanning signal line 6 is controlled by the scanning signal from the scanning signal line 6. When the TFT 8 is in the ON state, a data signal input through the data signal line 5 is input to the pixel electrode 7 and the auxiliary capacitor 12, and the pixel electrode 7, the counter electrode on the counter substrate side which is the upper substrate, and their electrodes A data signal is written into the liquid crystal capacitor composed of the liquid crystal sandwiched therebetween, and a data signal is also written into the auxiliary capacitor 12. On the other hand, when the TFT 8 is in the OFF state, input of the data signal from the data signal line 5 to the pixel electrode 7 and the auxiliary capacitor 12 is blocked, and the liquid crystal capacitor and the data signal written in the auxiliary capacitor 12 are held.

  By the way, in the liquid crystal display device 1 of the present embodiment, as shown in FIG. 1, spare wirings 15 are arranged in parallel to the data signal lines 5 next to the data signal lines 5. The spare wiring 15 is connected to the data signal line 5 and the connection line 16 in each pixel. Therefore, the data signal line 5, the spare wiring 15 and the connection line 16 have a so-called ladder shape. That is, it is a shape in which the letters H are joined together.

  The spare wiring 15 is provided to prevent display deterioration such as a line defect from occurring in the display panel 2 when a defect such as a disconnection occurs in a part of the data signal line 5. That is, when the ladder-shaped spare wiring 15 is used, the data signal from the data signal line 5 is constantly supplied to the spare wiring 15 through the connection line 16, so that the data signal line 5 is disconnected at any point. Even so, the data signal output from the data signal line driving unit 4 is supplied to the end through either the data signal line 5 or the spare wiring 15.

  In the liquid crystal display device 1 of the present embodiment, the temperature sensor 30 is provided in the pixel using the spare wiring 15.

  That is, in order to form the temperature sensor 30 in the pixel, at least a lead wire leading to the temperature sensor 30 is required. In this embodiment, the spare wiring 15 is used as the lead wire.

  Here, in order to use the spare wiring 15 as a lead wire of the temperature sensor 30, the spare wiring 15 to which the temperature sensor 30 is attached must not be electrically connected to the data signal line 5. Therefore, in the present embodiment, the communication line gaps 16a are formed in advance in all the communication lines 16 on the data signal line drive unit 4 side of the temperature sensor 30, and in the pixel in which the temperature sensor 30 is formed. A spare wiring gap 15a is formed on the terminal side of the spare wiring 15 connected to the temperature sensor 30 opposite to the data signal line driving unit 4. Thereby, the function as the lead wire of the temperature sensor 30 can be obtained on the data signal line driving unit 4 side of the spare wiring 15. At this time, the connecting line 16 does not have the connecting line gap 16a on the side opposite to the data signal line driving unit 4 from the auxiliary line gap 15a of the auxiliary line 15, that is, the terminal side, so that the function as the original auxiliary line 15 is maintained. Will be.

  In this embodiment, the function of the lead wire of the temperature sensor 30 is obtained on the data signal line drive unit 4 side, and the signal of the temperature sensor 30 is sent to the data signal line drive unit 4 side. Not limited to this, the function of the lead wire of the temperature sensor 30 can be on the side opposite to the data signal line driving unit 4. In this case, the communication line gap 16 a is provided in all of the connection lines 16 on the terminal side of the temperature sensor 30, and the auxiliary wiring is provided on the data signal line driving unit 4 side of the auxiliary wiring 15 forming the temperature sensor 30. A gap 15a is formed.

  The position of the temperature sensor 30 in the pixel is preferably provided, for example, in the vicinity of the TFT 8. This is because the TFT 8 is provided with a black matrix as a shielding member (not shown) so that the TFT 8 cannot be seen from the outside, and is preferably located below the black matrix. Therefore, it is preferably provided in the vicinity of the data signal line 5 or the scanning signal line 6. This is because a black matrix is provided above the data signal lines 5 and the scanning signal lines 6.

  Incidentally, the spare wiring 15 originally supplies a data signal using the spare wiring 15 when the data signal line 5 is disconnected.

  Therefore, in this embodiment, when the data signal line 5 is disconnected, the use of the spare wiring 15 as the lead wire of the temperature sensor 30 is abandoned. Therefore, when a disconnection occurs in the data signal line 5, the spare wiring 15 is disconnected using a laser device in the vicinity of the data signal line driving unit 4, thereby disconnecting the path from the temperature detection control unit 40 described later, One of the connection lines 16 is short-circuited using a laser device. Thereby, it can be easily used as the original spare wiring 15. This makes it impossible to measure the temperature of the pixel with the temperature sensor 30 as described above. However, in this case as well, in order to enable temperature measurement, for example, a control line (not shown) from a temperature detection control unit 40 (described later) connected to the spare wiring 15 is circulated around the periphery of the display panel 2, It is possible to make a detour on the opposite side to the data signal line driving unit 4. Thus, the temperature sensor 30 can measure the temperature by cutting the connecting line 16 on the side opposite to the data signal line driving unit 4.

  Next, the structure of the temperature sensor 30 will be described in detail.

In the present embodiment, the temperature sensor 30 is formed directly in the liquid crystal element. For example, as shown in FIG. 4, the temperature sensor 30 has aluminum (Al) electrodes 33a and 33b formed on a laminated body of a silicon dioxide (SiO ₂ ) oxide film 31 and a CrNi film 32 with a gap therebetween. It consists of what was formed. The temperature sensor 30 is a thermistor type sensor and utilizes a phenomenon in which the semiconductor carrier concentration varies exponentially with temperature. Therefore, the temperature can be measured by detecting the resistance of the gap. In this embodiment, the CrNi film 32 is used. However, the present invention is not limited to this, and an oxide semiconductor of a transition metal such as manganese (Mn), nickel (Ni), cobalt (Co), or the like is used. It is possible.

  The formation method of this temperature sensor 30 is demonstrated based on Fig.5 (a)-(h).

First, as shown in FIG. 5A, silicon dioxide (SiO ₂ ) oxide films 31 and 31 are formed by heat-treating a silicon (Si) wafer 34 polished on both sides. Next, as shown in FIG. 5B, a resist film 35 is formed by patterning on the lower oxide film 31. Next, as shown in FIG. 5C, after etching the lower oxide film 31 and the silicon (Si) wafer 34, the resist film 35 is removed. Next, after forming a CrNi film 32 as shown in FIG. 5D, an aluminum (Al) film 33 is vacuum-deposited to form a gap as shown in FIG. 5E. Thereby, aluminum (Al) electrodes 33a and 33b are formed.

Next, as shown in FIG. 5 (f), after forming the protective film 36 on the aluminum (Al) electrodes 33a and 33b, as shown in FIG. 5 (g), again the lower oxide film 31 and The silicon (Si) wafer 34 is etched to expose the upper silicon dioxide (SiO ₂ ) oxide film 31. Finally, as shown in FIG. 5H, the temperature sensor 30 is completed by removing the protective film 36. In the step shown in FIG. 5F, the protective film 36 is formed because re-etching is performed in the step shown in FIG. 5G, so that an aluminum (Al) electrode is formed during the re-etching. This is to prevent 33a and 33b from being eroded. In addition, about the formation method of this temperature sensor 30, the technique of a nonpatent literature 1 is applicable.

  In the present embodiment, one aluminum (Al) electrode 33 a is connected to the ITO (Indium Tin Oxide) auxiliary wiring 15, and the other aluminum (Al) electrode 33 b is connected to the auxiliary capacitance wiring 13. ing.

  Next, the reason why the temperature sensor 30 is formed in the pixel in the liquid crystal display device 1 of the present embodiment will be described.

  First, the liquid crystal display device 1 of the present embodiment is a high-definition device used as a display device for a computer. When a TV image or a moving image is projected on the high-definition liquid crystal display device 1, a slow response speed becomes a problem. That is, since the liquid crystal is a capacitive load, when the data signal voltage is applied to the pixel electrode, the liquid crystal has a property (hold characteristic) that maintains the alignment state changed according to the applied data signal voltage. For this reason, a flicker-free display screen can be obtained compared to a CRT or the like, but the response speed of the liquid crystal itself is slow, and particularly the halftone response does not respond sufficiently in one frame period of the video input signal. In some cases, there is a problem of deterioration in display quality such that an afterimage is seen.

  Therefore, in order to solve this problem, it is possible to improve the response speed by applying a change larger than the change of the input data to the liquid crystal module by overshoot driving or the like.

  By the way, in the liquid crystal display device 1, the temperature in the display panel 2 is affected by the ambient environment temperature and also varies during the display operation of the display panel 2. Therefore, the response speed cannot be improved properly unless a change equal to or greater than the change in the input data corresponding to the temperature in the display panel 2 is obtained, resulting in a display quality defect when displaying a moving image. Will do.

  Specifically, in the overshoot drive, as shown in FIG. 6A, for example, a data signal voltage corresponding to the gradation value 50 is applied in order to display the gradation value 30 at 25 ° C. . As a result, the gradation value 30 can be reached in a shorter time than the application of the data signal voltage for displaying the gradation value 30.

  Now, for example, as shown in FIG. 6B, in order to display a gradation value of 30 at 0 ° C., a data signal voltage corresponding to a gradation value of 80 is applied, so that gradation is achieved in 10 milliseconds. If it is assumed that the value 30 can be reached, and it is mistakenly recognized that the temperature of the liquid crystal element is 10 ° C., as shown in FIG. It will take. As a result, the response speed cannot cope with the change of the moving image.

  Therefore, in order to improve the response speed, it is necessary to correct the data signal voltage more accurately through accurate temperature management. In particular, when the power is turned on in winter, the response speed is slow because of the low temperature.

  Here, in the actual display panel 2, as shown in FIGS. 7A to 7D, it has been confirmed that the temperature of the display screen changes. The reason why the display panel 2 rises in temperature is that a backlight (not shown) is provided on the back side of the display panel 2 and is due to the radiant heat of the backlight. Specifically, when the ambient temperature is 24 ° C., the temperature distribution of the display panel 2 is 32 ° C. as a whole, as shown in FIG. 7A, 30 minutes after the power is turned on. Thereafter, 60 minutes after the power is turned on, as shown in FIG. 7B, the upper side up to about 4/5 is 36.8 ° C., and the lower side up to about 1/5 is 30.0 ° C. The reason why the temperature on the upper side of the display panel 2 is higher than that on the lower side is that heat moves upward. And as shown in FIG.7 (c), it will be in a substantially saturated state 90 minutes after a power supply ON, 38.3 degreeC to the upper side about 4/5, and the lower side about 1/5 is 30.0 degreeC. . Further, as shown in FIG. 7D, when the power is turned off from the state of FIG. 7C, the original state of FIG. 7A is restored in 30 minutes.

  Therefore, it takes 90 minutes to reach a saturated temperature distribution. In the above example, the initial ambient temperature starts from 24 ° C. However, if the initial ambient temperature starts from a lower initial ambient temperature, the saturation temperature is reached in a longer time, and the saturation temperature becomes lower than 38 ° C. Can be considered.

  Further, the temperature distribution of the display panel 2 has a large temperature change up to about 4/5 on the upper side. As a result, there is a clear difference in temperature difference between the temperature distribution until about 30 minutes after the power is turned on and the temperature distribution in the saturated state 90 minutes after the power is turned on. It can be seen that it is necessary to apply a voltage to the data signal line 5 based on the above. In particular, temperature management at a low temperature is important.

  In the present embodiment, based on the temperature distribution measurement result of the display panel 2 described above, for example, when the height of the display panel 2 is H as shown in FIG. For example, a 10-point temperature sensor 30 is arranged at the horizontal position. The reason why it is set to H / 3 or more from the lower end is that the temperature change in this region is large. The ten points are because in this embodiment, ten source driver ICs (not shown) in the data signal line driving unit 4 are used, and the temperature management of the display panel 2 is performed for each source driver IC. This is the purpose. Therefore, it is not necessarily limited to 10 points. Note that. In the present embodiment, the use of the spare wiring 15 from the data signal line driving unit 4 side is considered. However, the present invention is not limited to this, and the lower end of the display panel 2 can be obtained by drawing a detour around the display panel 2. It is possible to make 20 measurement points using the spare wiring 15 from the side.

  Further, in the present embodiment, based on the temperature distribution measurement result of the display panel 2 described above, the measurement points of the display panel 2 are provided at a plurality of locations except for the upper and lower ends H / 4 of the display panel 2 each. Is preferred. This is because the upper and lower ends H / 4 are in the vicinity of the end portion, and it can be considered that the entire temperature of the display panel 2 is not reflected.

  Moreover, it is preferable that the way of providing a plurality of places is at equal intervals in the horizontal direction, for example, rather than random positions. This is because an overall temperature distribution in the horizontal direction in the display panel 2 is obtained.

  By arranging the temperature sensors 30 at the points, the detection signals from the temperature sensors 30 are sent to the temperature detection control unit 40 as the temperature detection control means through the spare wiring 15 as shown in FIG. The temperature detection is performed by the temperature detection unit 41 provided inside the temperature detection control unit 40. In the present embodiment, for example, the temperature detection control unit 40 is provided at an end in the data signal line driving unit 4 as shown in FIG.

  Specifically, the temperature detection unit 41 calculates a current value based on the resistance value of each temperature sensor 30 by applying a power supply voltage to each temperature sensor 30, and is obtained in advance corresponding to this current value. The temperature of the pixel is detected based on the temperature.

  At this time, if the temperature sensor 30 is present on the data signal line 5, the wiring capacity of the data signal line 5 is slightly different. Therefore, compared to the data signal line 5 without the temperature sensor 30, the wiring capacity is slightly different. There is a possibility of slightly affecting the display. Further, it is obvious that the aperture ratio of the pixel in which the temperature sensor 30 is present is slightly lower than that of the pixel in which the temperature sensor 30 is not present. For this reason, it is preferable to disperse the arrangement of the temperature sensors 30 on the display panel 2 as much as possible. As an example, it is preferable that the projection horizontal intervals of the temperature sensors 30 scattered two-dimensionally in the display area are equal to each other. Further, it is preferable that the intervals between the data signal lines 5 on which the temperature sensors 30 on the display panel 2 are arranged are substantially equal. More preferably, the distance between the temperature sensors 30 in the vertical direction on the display panel 2 is substantially equal. Specifically, the temperature sensor distribution is as shown in FIG. Of course, the distribution of the temperature sensors 30 on the display panel 2 is not limited to the distribution of FIG.

  In the present embodiment, for example, ten measurement values are obtained. Therefore, the average value of these values is calculated by the temperature data calculation unit 42. Then, by sending the average value to the data signal line drive unit 4, the data signal line drive unit 4 calculates the overshoot voltage required for gradation display by the temperature parameter based on this average value, Output to each data signal line 5.

  As a result, the data signal voltage due to the temperature change can be corrected more accurately, and the display quality can be improved.

  In addition, this invention is not limited to said embodiment, A various change is possible within the scope of the present invention. For example, in the above embodiment, the temperature sensor 30 has a thermistor structure using the CrNi film 32, and the temperature sensor 30 is built in the pixel. However, the present invention is not particularly limited to this. For example, an existing diode can be embedded in a pixel, and a change in temperature can be detected by using a change in output voltage due to the temperature characteristics of the diode.

  In the present embodiment, the spare wiring 15 is used as the lead wire of the temperature sensor 30. However, the present invention is not limited to this, and a single lead wire can be provided. Further, although the spare wiring 15 has a ladder shape, the invention is not necessarily limited to this, and it is possible to use a spare wiring that is not a ladder shape.

  Further, in this embodiment, the display panel 2 is provided with a plurality of measurement points of 10 points. However, the present invention is not limited to this, and for example, one measurement point may be set at the center position of the display panel 2. Is possible.

  Thus, in the liquid crystal display device 1 of the present embodiment, the temperature sensor 30 is provided in at least one pixel in the display area of the display panel 2. The detection signal from the temperature sensor 30 is guided to the periphery of the display panel 2 by the spare wiring 15 embedded in the display panel 2.

  A temperature detection control unit 40 is provided in the data signal line drive unit 4 around the display panel 2, and the temperature detection unit 41 of the temperature detection control unit 40 is based on a detection signal from the temperature sensor 30. And detect the temperature. Further, the data signal line driving unit 4 outputs a data signal to the data signal line 5 based on the temperature in the pixel from the temperature detection control unit 40.

  Therefore, the actual temperature in the pixel is reflected in the data signal to the data signal line 5. Therefore, gradation control based on the actual temperature of the liquid crystal display element, not the estimated temperature, can be performed with respect to the response speed that is easily affected by temperature changes, so that the display area of the display panel 2 has an appropriate response speed. Display based on.

  Therefore, it is possible to provide the liquid crystal display device 1 that can grasp the temperature of the liquid crystal display element provided in the actual pixel, improve the response speed, and improve the display quality.

  Further, in the liquid crystal display device 1 according to the present embodiment, each data signal line 5 is provided with a ladder-shaped spare wiring 15 for avoiding data signal interruption due to disconnection of the data signal line 5. . The spare wiring 15 is used as a lead wire for the temperature sensor 30.

  Therefore, since the spare wiring 15 formed for other purposes is used as a lead wire of the temperature sensor 30, it is not necessary to provide a dedicated line separately. As a result, it is possible to prevent the manufacturing process from increasing significantly.

  Further, in the liquid crystal display device 1 of the present embodiment, the temperature sensor 30 is a thermistor type sensor formed by forming an element film in a pixel formation process.

  Therefore, the temperature sensor 30 is formed by sequentially forming element films in the pixel formation process. As a result, the temperature sensor 30 is completed by manufacturing the liquid crystal display device 1. For this reason, manufacture of the temperature sensor 30 is easy. Further, since the temperature sensor 30 is a thermistor type sensor built in the pixel formation process, it can be formed as a thin film and is compact. Therefore, even if it exists inside the liquid crystal display element, display is not hindered. Moreover, since the temperature sensor 30 is a thermistor type sensor, it has low power consumption. Therefore, the liquid crystal display device 1 is suitable as a temperature sensor.

  Further, in the liquid crystal display device 1 of the present embodiment, the data signal line driving unit 4 supplies a data signal voltage larger than the data signal voltage corresponding to the gradation value indicated by the video signal to the data signal line. That is, overshoot drive is adopted.

  Therefore, since overshoot driving is easily affected by temperature, it is necessary to grasp the pixel temperature. Therefore, the effect of providing the temperature sensor in the pixel is great.

  In the liquid crystal display device 1 of the present embodiment, the temperature sensor 30 is provided in the vicinity of the scanning signal line 6 or the data signal line 5.

  Therefore, since the black matrix is usually provided near the scanning signal line 6 or the data signal line 5, the temperature sensor 30 can be hidden. Further, when the temperature sensor 30 is provided at the center of the pixel, it is necessary to provide a black matrix in order to prevent the temperature sensor 30 from being seen, but this reduces the aperture ratio. However, since the temperature sensor 30 is provided in the vicinity of the scanning signal line 6 or the data signal line 5 in the present embodiment, the aperture ratio does not decrease.

  In the liquid crystal display device 1 of the present embodiment, the temperature sensor 30 is shielded by a black matrix. Therefore, the temperature sensor 30 can be surely hidden from view.

  Further, in the liquid crystal display device 1 of the present embodiment, the temperature sensor 30 is provided in a plurality of pixels excluding the upper and lower ends from the upper and lower ends in the display area. Therefore, a display area having a small temperature change can be excluded from measurement.

  Further, the temperature detection control unit 40 averages the detection signals from the plurality of temperature sensors 30 to obtain the in-pixel temperature. Therefore, it is possible to obtain the pixel temperature reflecting the entire display region where the temperature change in the display panel 2 is large.

  Further, in the liquid crystal display device 1 of the present embodiment, since the horizontal projection distances of the temperature sensors 30 scattered two-dimensionally in the display area are set to be equal to each other, the horizontal direction of the display panel 2 is It is possible to obtain pixel temperatures that are reflected evenly.

  Further, in the liquid crystal display device 1 of the present embodiment, since the data signal lines 5 are equally spaced, it is possible to reliably obtain pixel temperatures that reflect the horizontal direction of the display panel 2 evenly.

  Further, in the liquid crystal display device 1 of the present embodiment, the distances between the temperature sensors 30 in the vertical direction within the display area are equal to each other.

  Therefore, the distances between the temperature sensors 30 in the vertical direction in the display area are equally spaced from each other, and the temperature distribution can be obtained two-dimensionally and uniformly.

  The target of the display device of the present invention is a liquid crystal display device used for a liquid crystal monitor for moving images of a high-definition monitor note, and a HDTV (High Definition Television) that will appear in the future.

1, showing an embodiment of the present invention, is a structural diagram illustrating a temperature sensor provided in a liquid crystal display device. FIG. It is a block diagram which shows the structure of the display drive part of the said liquid crystal display device. FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. It is sectional drawing which shows the structure of the temperature sensor of the said liquid crystal display device. (A)-(h) is sectional drawing which shows the manufacturing process of the said temperature sensor. (A) shows overshoot driving, and is a graph showing the arrival time when an applied voltage of gradation 50 is applied to obtain gradation 30 at 25 ° C., and (b) shows overshoot driving. It is a graph which shows the arrival time when applying the applied voltage of gradation 80 in order to obtain gradation 30 at 0 ° C., and (c) is the applied voltage when it is mistakenly recognized as 0 ° C. in (b). It is a graph which shows the relationship between and arrival time. (A)-(d) is a front view which shows the temperature distribution of a display panel over time. It is a front view which shows the arrangement position of the temperature sensor in the display panel of the said liquid crystal display device. It is a block diagram which shows the structure of the temperature detection control part of the said liquid crystal display device. It is a block diagram which shows the arrangement position of the temperature sensor of the conventional liquid crystal display device. In the said conventional liquid crystal display device, it is a front view which shows the display panel which divided the display area into 4 parts. It is a block diagram which shows the arrangement position of the temperature sensor of the other conventional liquid crystal display device.

Explanation of symbols

1 Liquid crystal display device (display device)
2 Display panel (display unit)
3 Scanning signal line driving unit 4 Data signal line driving unit (data signal line driving means)
5 Data signal line 6 Scanning signal line 7 Pixel electrode 8 TFT (switch part)
15 Preliminary wiring (lead wire)
15a Preliminary wiring gap 16a Connection line gap 16 Connection line 30 Temperature sensor 40 Temperature detection control unit (temperature detection control means)
41 Temperature detector

Claims (9)

A plurality of scanning signal lines, a plurality of data signal lines to which video signals are supplied as data signals, and pixels connected via the switch portions corresponding to the intersections of the scanning signal lines and the data signal lines are arranged in a matrix In a display device having a display unit arranged in
A plurality of temperature sensors provided in the plurality of pixels in the display area of the display unit,
And lead the detection signals from the plurality of temperature sensors embedded in the display portion to lead the periphery of the display unit,
Temperature detection control means for detecting temperature based on detection signals from the plurality of temperature sensors;
Based on the pixel the temperature from the temperature detection control means, and a data signal line drive circuit for outputting a data signal to the data signal lines are provided,
The display device, wherein the plurality of temperature sensors are two-dimensionally scattered in the display area, and are provided so that horizontal intervals of the temperature sensors are equal to each other . Each of the data signal lines is provided with a ladder-shaped spare wiring for avoiding data signal interruption due to disconnection of the data signal line,
The display device according to claim 1, wherein the spare wiring is used as the lead wire. The display device according to claim 1, wherein the plurality of temperature sensors are formed of a thermistor type sensor formed by forming an element film in a pixel forming step. The data signal line driving means supplies a data signal voltage larger than the data signal voltage corresponding to the gradation value indicated by the video signal to the data signal line based on the temperature in the pixel from the temperature detection control means. The display device according to any one of claims 1 to 3, wherein the display device is characterized. The display device according to claim 1, wherein the plurality of temperature sensors are provided at positions shielded by a shielding member provided above the scanning signal lines and the data signal lines . Wherein the plurality of temperature sensors, the display device according to claim 1, characterized in that it is shielded by the shielding member. When the vertical height in the display area of the display unit is H,
Each of the plurality of temperature sensors is provided at a location excluding H / 4 from the inner end of the display area,
The display device according to claim 1, wherein the temperature detection control unit averages detection signals from the plurality of temperature sensors to obtain an in-pixel temperature. Display device according to claim 1, wherein the interval of the data signal lines in said plurality of temperature sensors within the display area to be arranged equally spaced. Display device according to claim 1, wherein a distance between the plurality of temperature sensors in the vertical direction of the display area is equidistant from each other.

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