KR20120001416A - Image display device - Google Patents

Abstract

PURPOSE: A video display device is provided to increase the picture quality of a video display device by increasing the reaction speed of a liquid crystal by generating heat in a three-dimensional display mode. CONSTITUTION: A display panel displays an image selected by a user in a two-dimensional video and a three-dimensional video. A driving unit drives the display panel. A controller(180) generates a control signal according to a video which is selected by a user and controls the driving unit. A switch unit(210) is turned on/off according to the control signal which is generated by the controller. A heater(220) is arranged in a domain of the display panel.

Description

Video display device {IMAGE DISPLAY DEVICE}

The present invention relates to an image display apparatus, and more particularly, to an image display apparatus capable of realizing a 2D image and a 3D image and improving a response speed.

Recently, a stereoscopic image display apparatus has been widely applied in various fields such as medical images, games, advertisements, education, military, etc., and holography or stereoscopy has been widely studied as a method for displaying stereoscopic images.

Although holographic methods are ideal display methods, they require a coherent light source, and it is difficult to record and reproduce large objects located at a long distance.

On the other hand, stereoscopic method causes two-dimensional images with binocular disparity to show two-dimensional images separately on both eyes of a person, thereby inducing a stereoscopic feeling. This method uses two planar images, making it simple to implement and displaying three-dimensional images with high resolution and great depth. Such stereoscopic methods include eyeglasses using polarization and shutters and non-glasses to form a gaze by directly separating images from a display as a means for viewing separate images from both eyes.

The non-glass stereoscopic image display method has a disadvantage of being limited to a small number of people due to the fixed viewing range, but it is generally preferred to the glasses type, which is inconvenient to wear separate glasses. There is a growing tendency to adopt parallax barriers.

The parallax barrier has a vertical or horizontal slit in front of an image corresponding to both left and right eyes, and separates and observes a three-dimensional image synthesized through the slit to feel a three-dimensional feeling.

2D / 3D switching display is applied to the practical use of the three-dimensional display to overcome the fatigue caused by using the optical illusion of both eyes, there is a way to implement using a parallax barrier as a liquid crystal. That is, when power is applied to the liquid crystal, some pixels serve as a barrier by blocking / absorbing light emitted from the backlight, and the other pixels without power are used as slit of the parallax barrier. To implement stereoscopic images.

In addition, when no power is applied to the liquid crystal, a parallax barrier is not formed, and the same image is transmitted to the right eye and the left eye of the viewer to display a two-dimensional image.

On the other hand, in an image display apparatus for selectively implementing a 2D / 3D image, the duty ratio of the backlight is different when a 2D image is displayed on a liquid crystal display device and when a 3D image is displayed. Specifically, the duty ratio of the backlight of the liquid crystal display device in which the 3D image is implemented is reduced than the duty ratio of the backlight of the liquid crystal display device in which the 2D image is implemented.

 Therefore, in the case of implementing the 3D image, the duty ratio of the backlight of the LCD is reduced, and thus heat generated in the backlight is reduced as compared with the case of implementing the 2D image. As a result, when the 3D image is implemented, the reaction speed of the liquid crystal is reduced, thereby causing a crosstalk phenomenon, thereby causing a problem of deterioration of image quality.

The present invention includes a heating element for generating heat to drive the heating element in the three-dimensional image display mode selected by the user to improve the response speed of the liquid crystal in the three-dimensional image display mode to minimize crosstalk phenomenon to improve the image quality It is an object of the present invention to provide a video display device that can be made.

An image display apparatus according to an embodiment of the present invention is an image display apparatus for selectively displaying a two-dimensional image and a three-dimensional image, the image display apparatus comprising: a light source unit for providing light, and a two-dimensional image using the light provided to the light source unit; A display panel for displaying an image selected by the user of the three-dimensional image, a driving unit for driving the display panel, a control unit for controlling the driving unit and the light source unit and generating a control signal different in logic according to the image selected by the user And at least one switch unit turned on / off according to the control signal generated by the controller and at least one heat generating unit generated by on / off of the switch unit.

The image display device according to the present invention is a three-dimensional display device including a switch unit which is turned on / off in accordance with a display mode selected by a user among two-dimensional and three-dimensional display modes, and a heating unit controlled by the switch unit and generating heat. By generating heat in the image display mode, the reaction speed of the liquid crystal may be improved, thereby minimizing crosstalk, thereby improving image quality.

1 is a view schematically showing an image display device according to an embodiment of the present invention.
2 is a circuit diagram illustrating a switch unit and a heat generating unit of FIG. 1.
3 is a flowchart illustrating an operation procedure of the switch unit and the heat generating unit of FIG. 1.
FIG. 4A is a diagram illustrating a location of a heating unit arranged in each region of the display panel, and FIG. 4B is a diagram illustrating a temperature change measured for each region of FIG. 4A.

Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings.

1 is a view schematically showing an image display device according to an embodiment of the present invention.

As illustrated in FIG. 1, the image display apparatus 100 according to an exemplary embodiment of the present invention may include a light source unit 120, and a light source unit 120 that crosses light from the light source unit 120 to a first polarization or the first polarization. The image signal is transmitted by the polarization switching unit 135, the slit 150, and the barrier 300 alternately arranged to emit two polarized light, and the light passing through the parallax barrier 155. And a display panel 170 for modulating according to the present invention.

The display panel 170 may be implemented as a transmissive display device and may be implemented as a liquid crystal display device as an example. When the liquid crystal display device is applied as the display panel 170, the display panel 170 has a liquid crystal layer formed between two glass substrates.

A TFT array is formed on the lower glass substrate. The TFT array includes a plurality of data lines to which a data voltage is supplied, and a plurality of gate lines to define a pixel area crossing the plurality of data lines and to supply a scan pulse. And a plurality of TFTs formed in the pixel region, a plurality of pixel electrodes for charging data voltages in the liquid crystal cells, and a storage capacitor connected to the pixel electrodes to maintain the voltage of the liquid crystal cells.

A color filter array is formed on the upper glass substrate, and the color filter array includes a black matrix, a color filter, and the like. A column spacer may be formed between the lower and upper glass substrates to maintain a cell gap of the liquid crystal cell.

The light source unit 120 may include a reflective plate 110 to recycle the light reflected from the barrier 160. The light source unit 120 generally illuminates unpolarized light, and the polarization switching unit 135 transmits light of non-polarized light illuminated by the light source unit 120 to transmit light of linearly polarized light by electrical control. 130 and a phase delay means 140 for converting the polarization of the light transmitted through the polarization means 130 into polarization orthogonal thereto depending on the electrical signal, and a dual brightness enhancement film (DBEF) may be employed. Can be.

The phase delay unit 140 switches the polarization by delaying the phase of the incident light. For example, when there is no electrical signal (off), the incident light is transmitted as it is without phase delay, and when there is an electrical signal (on). Delays the phase of incident light and converts it into orthogonal polarization.

The parallax barrier 155 is a slit 150 that transmits light and a barrier 160 that blocks light alternately arranged to form a 3D image by binocular parallax. The arrangement of the slit 150 and the barrier 160 can be variously changed.

The display panel 170 modulates the light transmitted through the parallax barrier 155 according to an image signal to form an image.

In addition, the image display apparatus 100 according to an exemplary embodiment of the present invention drives the first driver 190 for driving the display panel 170, the light source unit 120, and the polarization switching unit 135. The second driver 200 for controlling the controller, the controller 180 for controlling the first and second drivers 190 and 200, and on / off according to a display mode selected by the user among two-dimensional and three-dimensional display modes. Further comprising a switch unit 210 and the heat generating unit 220 for generating heat under the control of the switch unit 210.

 In addition, the image display apparatus 100 may further include a temperature sensing means (not shown) for determining whether the temperature generated by the heat generating unit 220 corresponds to a predetermined temperature level.

The first driver 190 may include a data driver for supplying a data voltage to data lines of the display panel 170, and a gate driver for sequentially supplying scan pulses to gate lines of the display panel 170. And a common voltage generator for supplying a common voltage to the common electrode of the display panel 170.

The second driver 200 controls the on / off time of the backlight provided in the light source unit 120 according to a control signal provided from the controller 180 to drive the light source, and the polarization switch The electrical signal is provided to the unit 135.

The controller 180 controls the first and second drivers 190 and 200 and generates a switch control signal for controlling the switch unit 210 according to the display mode selected by the user. The switch control signal generated by the controller 180 is provided to the switch unit 210.

The controller 180 generates a switch control signal of a low logic level when the user selects the 2D display mode, and generates a switch control signal of a high logic level when the user selects the 3D display mode. do. In addition, the controller 180 includes temperature sensing means for determining whether the heat generated by the heat generating unit 220 corresponds to a reference temperature set by an engineer. The controller 180 controls the heating of the heat generating unit 220 by the temperature sensing means.

The switch unit 210 is turned on / off according to the logic level of the switch control signal from the controller 180. For example, the switch unit 210 is turned on by a switch control signal of a high logic level and is turned off by a switch control signal of a low logic level.

The heat generating unit 220 generates heat when the switch unit 210 is On, and does not generate heat when the switch unit 210 is Off.

As illustrated in FIG. 2, the switch unit 210 may include a field effect transistor (FET) switch element, and the heat generating unit 220 may include a metal resistor. The switch unit 210 may be composed of all the elements that can be turned on / off by the switch control signal from the control unit 180, the heat generating unit 220 includes a metal resistor It can be composed of all elements that can generate heat.

In this case, the number of the switch unit 210 and the heat generating unit 220 may be provided in at least one or more inside the image display device 100.

The switch control signal provided from the controller 180 is supplied to the gate terminal G of the FET switch element, and the FET switch element is turned on when the switch control signal is at a high logic level. When the FET switch element is turned on, current flows through the metal resistor R to generate heat.

The FET switch element is turned off when the switch control signal is at a low logic level. When the FET switch element is turned off, no current flows through the metal resistor R, so that the metal resistor R does not generate heat.

That is, the switch unit 210 is turned off when the image display apparatus 100 is driven in the 2D display mode, and is turned on when the image display apparatus 100 is driven in the 3D display mode. do. Similarly, the heat generating unit 220 does not generate heat when the image display apparatus 100 is driven in the 2D display mode, and generates heat when the image display apparatus 100 is driven in the 3D display mode.

When the image display apparatus 100 is driven in a display mode for displaying a 3D image, the heat generator 220 generates heat of a predetermined temperature, which is provided in the display panel 170. The response speed of the liquid crystal can be improved.

When the image display apparatus 100 is driven in the 3D display mode, the duty ratio of the backlight included in the light source unit 120 of FIG. 1 is reduced to react the liquid crystal of the display panel 170. The speed will decrease.

To compensate for this, the image display apparatus 100 according to an exemplary embodiment of the present invention includes a heating unit 220 so that the heating unit 220 when the image display apparatus 100 is driven in the 3D display mode. The heat is generated to generate heat of a predetermined temperature to improve the reaction rate of the liquid crystal provided in the display panel 170.

Accordingly, when the image display apparatus 100 according to the embodiment of the present invention is driven in a display mode for displaying a 3D image, the image display apparatus 100 generates heat at a predetermined temperature by driving the heat generating unit 220. The image quality may be improved by compensating for the response speed of the liquid crystal which may occur due to the reduction in the duty ratio of the backlight.

On the other hand, the temperature sensing means provided in the control unit 180 determines whether the temperature of the heat generated in the heat generating unit 220 is less than the reference temperature (for example, 37 ℃) to control the switch unit 210. . For example, when the temperature of the heat generated by the heat generating unit 220 is less than or equal to the reference temperature, the temperature sensing means maintains the on state of the switch unit 210. When the temperature of the heat generated by the heat generating unit 220 is greater than the reference temperature, the temperature sensing means controls the on state of the switch unit 210 to an off state. Therefore, when the temperature of the heat generated by the heat generating unit 220 is greater than the reference temperature, the heat generating unit 220 does not generate heat.

3 is a flowchart illustrating an operation procedure of the switch unit and the heat generating unit of FIG. 1.

1 and 3, when the display mode selected by the user when the image display apparatus 100 is driven (Power On) is a 3D display mode, the controller 180 returns to the switch unit 210. Provides a high level switch control signal.

The switch unit 210 is turned on so that a current flows in the heat generating unit 220 to heat the heat generating unit 220. After the heating unit 220 generates heat and a predetermined time passes, the temperature sensing unit provided in the control unit 180 determines whether the temperature of the heat generated by the heating unit 220 is 37 ° C. or less.

When the temperature of the heat generated by the heat generating unit 220 is 37 ° C. or less, the switch unit 210 maintains an on state so that the heat generating unit 220 generates heat.

On the other hand, when the temperature of the heat generated by the heat generating unit 220 is greater than 37 ℃, the switch unit 210 is turned off (Off) so that the heat generating unit 220 does not generate heat.

When the display mode selected by the user is the 2D display mode, the controller 180 provides a switch control signal of a low level to the switch unit 210. The switch unit 210 is turned off by the low level switch control signal so that the heat generating unit 220 does not generate heat.

As described above, the image display apparatus according to the exemplary embodiment of the present invention drives the heat generator 220 to generate heat at a predetermined temperature when the image display apparatus is driven in a display mode for displaying a 3D image. The image quality may be improved by compensating for the response speed of the liquid crystal, which may be caused by a reduced duty ratio, to prevent cross talk.

Table 1 below shows the relationship between the internal temperature of the display panel and the crosstalk.

Table 1 shows the crosstalk generated in the three-dimensional display mode, although the change in luminance (nit) shown in the center portion of the display panel is not large when the temperature in the center portion of the display panel is 30 ° C, 35 ° C, 40 ° C, or 45 ° C. (C / T) shows decreasing with increasing temperature. This is because the display panel includes a heating unit to increase the internal temperature of the display panel to improve the reaction speed of the liquid crystal.

Measuring temperature ℃ 30 35 40 45
Luminance
(center)
①W⇒W

nit
46.63 45.78 45.83 44.93 ②B⇒W 37.78 40.9 41.9 41.98 ③W⇒B 3.857 3.137 2.324 1.828 ④B⇒B 0.042 0.039 0.039 0.040 3D C / T % 10.1 7.6 5.5 4.3

In addition, as illustrated in FIGS. 4A and 4B, when nine heating parts are provided for each area of the display panel, when the temperature is measured for each area, the center parts 3, 6, and 9 of the display panel are different from each other (1). It can be seen that the temperature (46.2 ° C, 43.6 ° C, 46.7 ° C) increases compared to 2, 4, 5, 7, 8). Therefore, when the heat generating unit is provided in the center of the display panel, the internal temperature is increased as compared with the case where the heat generating unit is provided in the other area, thereby improving the reaction speed of the liquid crystal.

100: image display device 110: reflection plate
120: light source unit 130: polarization means
135: switching polarization unit 140: phase delay means
150: Slit 155: Parallax barrier
160: Barrier 170: Display panel
180: control unit 190: first drive unit
200: second drive unit 210: switch unit
220: a heat generation part

Claims (8)

An image display apparatus for selectively displaying two-dimensional images and three-dimensional images,
A light source unit for providing light;
A display panel configured to display an image selected by a user among a 2D image and a 3D image using light provided to the light source unit;
A driving unit for driving the display panel;
A control unit controlling the driving unit and the light source unit and generating a control signal having a different logic according to an image selected by a user;
A switch unit turned on / off according to a control signal generated by the controller; And
And at least one heat generating unit arranged in each area of the display panel and generating heat by on / off of the switch unit. The method according to claim 1,
The control unit generates a low logic control signal when the user selects the 2D image, and the user generates a high logic control signal by selecting the 3D image and provides the control signal to the switch unit. Image display device. The method of claim 2,
The switch unit is turned on when the control signal of the high logic is provided to control the heating unit to generate heat, and is off when the control signal of the low logic is provided to the heat generating unit. The video display device characterized in that the control not to generate heat. The method according to claim 1,
The switch unit includes a field effect transistor (FET) that is turned on / off by the switch control signal. The method according to claim 1,
And the heat generating unit includes a metal resistor that is controlled by the switch and generates heat. The method according to claim 1,
And the control unit includes temperature sensing means for controlling whether the temperature of the heat generated by the heat generating unit is equal to or less than a reference temperature to control on / off of the switch unit. The method of claim 6,
The temperature sensing means maintains the switch on when the temperature of the heat generated by the heat generating unit is equal to or less than a reference temperature, and turns off the switch unit when the temperature of the heat generated by the heat generating unit is greater than the reference temperature. Off) control the video display device characterized in that the control. The method according to claim 1,
And the display panel is a liquid crystal display device.

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