TWI442380B - Three-dimensional liquid crystal display device and backlight adjustment method thereof - Google Patents

Description

Three-dimensional liquid crystal display device and backlight adjustment method thereof

The present invention relates to a three-dimensional liquid crystal display device, and more particularly to a backlight adjustment method for a three-dimensional liquid crystal display device.

In the liquid crystal display device, the reaction rate of the liquid crystal therein is not constant. In fact, the reaction rate of the liquid crystal has a certain correlation with the environmental parameters of the liquid crystal display device. Among them, temperature, humidity and the continuous working time of the liquid crystal display device are all important factors that affect the reaction rate of the liquid crystal.

Please refer to FIG. 1. FIG. 1 is a waveform diagram showing the operation of a conventional liquid crystal display device. Wherein, the vertical synchronization signal VSYNC is used to indicate the vertical synchronization period of the liquid crystal display device. In the illustration of Fig. 1, the vertical synchronizing signal VSYNC is a period of a positive voltage pulse, that is, a vertical synchronizing period of the liquid crystal display device. In addition, the backlight turn-on signal BLON indicates the turn-on time of the backlight panel of the liquid crystal display device. Wherein, when the backlight on signal BLON is a positive voltage pulse, the backlight panel of the liquid crystal display device is correspondingly illuminated.

In the conventional liquid crystal display device, after the time T0 after the vertical synchronization period, the liquid crystal display device finishes receiving the display material of one frame to be displayed. Further, after the time T1, all the liquid crystals in the liquid crystal display device complete the reaction operation (the state in which the flip conduction is stabilized) in accordance with the received display data. After all the liquid crystals have completed the reaction operation corresponding to the received display data, the backlight panel of the liquid crystal display device is lit. In order to maintain the basic brightness, the lighting time of the backlight panel is continued until time t1 after the next vertical synchronization period V1.

In the above conventional practice, since the lighting time of the backlight panel is fixed, it cannot be adjusted according to the reaction rate of the liquid crystal. Therefore, such a display device may cause a more serious image crosstalk phenomenon when the reaction rate of the liquid crystal changes depending on environmental parameters.

The present invention provides a liquid crystal display device which effectively reduces the phenomenon of cross talk caused by changes in environmental parameters.

The invention provides a backlight adjusting method for a liquid crystal display device, which effectively reduces the phenomenon of image crosstalk caused by changes in environmental parameters.

The invention provides a liquid crystal display device, which comprises an environment parameter detecting circuit, a backlight driving circuit and a three-dimensional image receiver. The environmental parameter detecting circuit detects an environmental parameter of an environment to which the liquid crystal display device belongs. The liquid crystal display device generates an adjustment signal according to environmental parameters. The backlight driving circuit is coupled to the environmental parameter detecting circuit, and receives and adjusts the startup time of the backlight panel of the liquid crystal display device according to the adjustment signal and the vertical synchronization period. The 3D image receiver has two 3D image receiving units for alternately receiving display images according to the startup time.

In an embodiment of the invention, the backlight driving circuit adjusts the turn-off time of the backlight panel according to the startup time of the backlight panel.

In an embodiment of the invention, the backlight driving circuit described above fixes the off time of the backlight panel.

In an embodiment of the invention, the environmental parameter detecting circuit includes a working time counter for calculating a continuous working time of the liquid crystal display device.

In an embodiment of the invention, the environmental parameter detecting circuit includes a controller. The controller performs an arithmetic operation on the environmental parameters and generates an adjustment signal.

In an embodiment of the invention, the environmental parameter detecting circuit further includes a lookup table. The lookup table records the operation result of the arithmetic operation and the relative relationship of the adjustment signals. The controller performs a lookup operation on the lookup table according to the operation result of the arithmetic operation, and generates an adjustment signal.

In an embodiment of the invention, the backlight driving circuit adjusts a time difference between a startup time of the backlight panel and a vertical synchronization period according to the adjustment signal.

The invention further provides a backlight adjustment method for a liquid crystal display device, comprising: detecting an environmental parameter of an environment to which the liquid crystal display device belongs. And, an adjustment signal is generated according to the environmental parameter. Then, the startup time of the backlight panel that activates the liquid crystal display device is dynamically adjusted according to the adjustment signal and the vertical synchronization period. And, the left eye image and the right eye image of the display image are alternately received according to the startup time.

Based on the above, the present invention dynamically adjusts the change of the environmental parameter of the environment to which the liquid crystal display device belongs, and dynamically adjusts the illuminated time point of the backlight panel of the liquid crystal display device according to the obtained change of the environmental parameter, and according to the backlight The adjustment of the illuminated time point of the panel to synchronously adjust the image receiving operation of the 3D image receiver. In this way, the crosstalk phenomenon of the display image generated by the liquid crystal display device in which the inversion speed of the liquid crystal changes with the environmental parameters can be effectively compensated, thereby improving the display quality of the liquid crystal display device.

The above described features and advantages of the present invention will be more apparent from the following description.

Please refer to FIG. 2. FIG. 2 is a schematic diagram of a three-dimensional (3D) liquid crystal display device according to an embodiment of the present invention. The liquid crystal display device 200 includes an environmental parameter detecting circuit 210, a backlight driving circuit 220, a backlight panel 230, and a three-dimensional image receiver 240. The environmental parameter detecting circuit 210 is configured to detect an environmental parameter EPA of the environment to which the liquid crystal display device 200 belongs. The adjustment signal TUN is generated according to the detected and obtained environmental parameters. The environmental parameter EPA detected by the environmental parameter detecting circuit 210 includes at least one of temperature, humidity, and continuous working time of the liquid crystal display device 200.

The backlight driving circuit 220 is coupled to the environmental parameter detecting circuit 210. The backlight driving circuit 220 receives the adjustment signal TUN generated by the environmental parameter detecting circuit 210, and dynamically adjusts the startup time of the backlight panel 230 of the liquid crystal display device 200 according to the adjustment signal TUN and the vertical synchronization period. The backlight driving circuit 220 obtains information during vertical synchronization by the received vertical synchronization signal VSYNC. Briefly, the backlight driving circuit 220 can know the time interval during vertical synchronization by determining the time during which the vertical synchronizing signal VSYNC generates a positive voltage pulse.

In addition, the backlight driving circuit 220 knows that the startup time of the backlight panel 230 is to be adjusted by the received adjustment signal TUN. In short, when the adjustment signal TUN indicates that the startup time of the backlight panel 230 needs to be advanced, the backlight driving circuit 220 can shorten the time difference between the vertical synchronization period and the startup time of the backlight panel 230. relatively. If the adjustment signal TUN indicates that the startup time of the backlight panel 230 needs to be delayed, the backlight driving circuit 220 can extend the time difference between the vertical synchronization period and the startup time of the backlight panel 230.

The three-dimensional image receiver 240 has two three-dimensional image receiving units 241 and 242. The three-dimensional image receiving units 241 and 242 alternately receive the display images generated by the display panel matched by the backlight panel according to the startup time of the backlight panel. That is, the three-dimensional image receiving unit 241 of the three-dimensional image receiver 240 (for example, three-dimensional glasses) (for example, the left eye of the glasses) corresponds to the display image generated by the display panel when the receiving backlight panel is activated for an odd number of times (for example, the left eye). The image receiving unit 242 (for example, the right eye of the glasses) corresponds to the display image (for example, the right eye image) generated by the display panel when the receiving backlight panel is activated for an even number of times.

Specifically, when the environmental parameter detecting circuit 210 detects the change of the environmental parameter, the reaction rate of the liquid crystal is accelerated (the reaction time is decreased), the environmental parameter detecting circuit 210 correspondingly generates the vertical synchronization period and the backlight. The adjustment signal TUN of the time difference in the startup time of the panel 230. In contrast, if the environmental parameter detecting circuit 210 detects a change in the environmental parameter, the reaction rate of the liquid crystal is slowed down (the reaction time is increased), and the environmental parameter detecting circuit 210 correspondingly generates the vertical synchronization period and the backlight panel. The adjustment signal TUN of the time difference in the start-up time of 230. The backlight driving circuit 220 reduces or raises the time difference between the vertical synchronization period and the startup time of the backlight panel 230 according to the received adjustment signal TUN.

Please refer to FIG. 3, which illustrates an embodiment of an environment parameter detecting circuit according to an embodiment of the present invention. The environmental parameter detecting circuit 210 includes a working time counter 211 and a controller 212. The working time counter 211 is used to calculate the continuous working time of the liquid crystal display device. In the present embodiment, the operating time counter 211 receives the signal DON for starting the liquid crystal display device, and performs an operation of counting after the liquid crystal display device is activated. The working time counter 211 transmits the result TOP of its counting to the controller 212. In addition, when the liquid crystal display device is turned off, the working time counter 211 will stop counting and perform a reset operation according to the signal DON, and the working time counter 211 re-counts after the liquid crystal display device is restarted. . As a result, the larger the value of the count result TOP, the longer the continuous operation time of the liquid crystal display device is.

The controller 212 may receive an environmental parameter EPA1 indicating at least one of an ambient temperature and an ambient humidity in addition to receiving the result TOP of the count. The controller 212 can perform an arithmetic operation according to the received environmental parameter EPA1 and the result TOP of the counting, and thereby know the change state of the reaction rate of the liquid crystal under the environmental parameters at the time, and thereby generate the adjustment signal TUN.

In this embodiment, the controller 212 can directly obtain the adjustment signal TUN according to the count result TOP and the environmental parameter EPA1 through an arithmetic operation. Of course, to reduce the complexity of the arithmetic operations performed by the controller 212, the environmental parameter detection circuit 210 may further include a lookup table 213. The lookup table 213 is coupled to the controller 212 and is used to record the relative relationship between the operation result of the arithmetic operation performed by the controller 212 and the adjustment signal TUN. In this way, the controller 212 can perform only a simple arithmetic operation, and then through the operation result obtained by the simple arithmetic operation, the lookup table 213 can be used to find the corresponding adjustment signal.

In the following, a practical example will be presented to explain the spirit of the invention to those skilled in the art.

Please refer to FIG. 4. FIG. 4 is a diagram showing an action waveform of an embodiment of the present invention. The curve 420 represents the waveform of the backlight ON signal BLON before the adjustment, and the curve 410 represents the waveform of the adjusted backlight ON signal BLON. The period in which the vertical synchronizing signal VSYNC is a positive voltage pulse is expressed as a vertical synchronizing period of the liquid crystal display device. Further, when the liquid crystal display device is activated, the backlight panel of the liquid crystal display device is turned on or off in accordance with the backlight turn-on signal BLON of the curve 420. Wherein, after the time T0 after the vertical synchronization period, the liquid crystal display device finishes receiving the display material of one frame to be displayed, and the reaction time required for the liquid crystal is time T1.

After the liquid crystal display device is activated for a period of time (for example, 10 minutes), the liquid crystal display device finishes receiving the display material of a picture frame to be displayed due to the rise of the liquid crystal reaction rate, and the reaction time required for the liquid crystal is determined by the time T1. Shorten to time T1'. Accordingly, the backlight driving circuit adjusts the backlight ON signal BLON in accordance with the curve 420, and causes the backlight panel to be lit after the time T0+T1' after the vertical synchronization period. As such, in curve 420, the lighting time of the backlight panel continues until time t1 after the next vertical synchronization period V1, and in curve 410, the synchronization is reduced to t1'. That is to say, the image crosstalk phenomenon that may be generated by the liquid crystal display device can be effectively reduced.

On the other hand, the action of turning on the left-eye glasses GL of the three-dimensional image receiver and the action of turning on the right-eye glasses GR are interleaved. In the illustration of FIG. 4, the left-eye glasses GL are first turned on according to the backlight turn-on signal BLON being pulled up to a high level. After the left eye glasses GL are turned off, the right eye glasses GR are turned on according to the next backlight turn-on signal BLON being pulled up to a high level.

It is to be noted that the off time of the left eye glasses GL and the right eye glasses GR can be adjusted as the backlight on signal BLON is adjusted. That is, with the off time of the backlight on signal BLON (pulled from the high level to the low level), the off time of the left eye glasses GL and the right eye glasses GR can be adjusted to the time TOF1. Of course, the closed time of the left-eye glasses GL and the right-eye glasses GR may not need to be adjusted with the backlight ON signal BLON, but may be fixed at the time TOF2. In this way, when the startup time of the backlight panel is advanced, the time interval at which the left-eye glasses GL and the right-eye glasses GR are activated is relatively increased.

Please pay special attention here, when the liquid crystal display device is applied in a three-dimensional display system, the longer the illumination time of the backlight panel continuing to the next vertical synchronization period, the longer the backlight panel will be generated in the user's 3D glasses. Serious image crosstalk. Therefore, by using the environment parameter to dynamically adjust the startup time point of the backlight panel according to the embodiment of the present invention, the occurrence of the image crosstalk phenomenon can be effectively reduced in the three-dimensional display system.

Next, please refer to FIG. 5. FIG. 5 is a flowchart of a backlight adjustment method of a three-dimensional liquid crystal display device according to an embodiment of the present invention. The steps include: first, measuring an environmental parameter of an environment to which the liquid crystal display device belongs. And an adjustment signal is generated according to the environmental parameter (S510). Then, an adjustment signal is generated according to the environmental parameters. Next, the startup time of the backlight panel that activates the liquid crystal display device is dynamically adjusted in accordance with the adjustment signal and the vertical synchronization period (S520). Then, the left eye image and the right eye image of the display image are alternately received according to the startup time (S530). The details of the backlight adjustment are described in detail in the foregoing embodiments and implementation methods, and will not be described in detail below.

In summary, the present invention dynamically adjusts the startup time point of the backlight panel by dynamically changing the environmental parameters of the environment to which the liquid crystal display device belongs. In this way, the startup time of the backlight panel will immediately correspond to the reaction rate of the liquid crystal, effectively reducing the image crosstalk phenomenon caused by the unsuitability of the startup time of the backlight panel.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

200. . . Liquid crystal display device

210. . . Environmental parameter detection circuit

220. . . Backlight driving circuit

230. . . Backlight panel

213. . . Lookup table

211. . . Time counter

212. . . Controller

240. . . 3D image receiver

241, 242. . . 3D image receiving unit

VSYNC. . . Vertical sync signal

BLON. . . Backlight on signal

T0, T1, T1', t1, t1', TOF1, TOF2. . . time

V1. . . Vertical synchronization period

EPA, EPA1. . . Environmental parameters

TUN. . . Adjustment signal

VSYNC. . . Vertical sync signal

TOP. . . Counting result

DON. . . signal

410~420. . . curve

GL. . . Left eye glasses

GR. . . Right eye glasses

S510~S530. . . Backlight adjustment step

FIG. 1 is a view showing an operation waveform of a conventional liquid crystal display device.

2 is a schematic diagram of a three-dimensional liquid crystal display device according to an embodiment of the invention.

FIG. 3 illustrates an embodiment of an environmental parameter detecting circuit according to an embodiment of the present invention.

FIG. 4 is a diagram showing an action waveform of an embodiment of the present invention.

FIG. 5 is a flow chart showing a backlight adjustment method of a three-dimensional liquid crystal display device according to an embodiment of the invention.

200. . . Liquid crystal display device

210. . . Environmental parameter detection circuit

220. . . Backlight driving circuit

230. . . Backlight panel

240. . . 3D image receiver

241, 242. . . 3D image receiving unit

EPA. . . Environmental parameters

TUN. . . Adjustment signal

VSYNC. . . Vertical sync signal

Claims (15)

A three-dimensional liquid crystal display device includes: an environmental parameter detecting circuit that detects an environmental parameter of an environment to which the liquid crystal display device belongs, and generates an adjustment signal according to the environmental parameter; and a backlight driving circuit coupled to the environmental parameter a detecting circuit that receives and adjusts a start time of a backlight panel that activates the liquid crystal display device according to the adjustment signal and a vertical synchronization period; and a three-dimensional image receiver that has two three-dimensional image receiving units, and the three-dimensional image receiving unit The image receiving unit alternately receives a display image according to the startup time. The liquid crystal display device of claim 1, wherein the backlight driving circuit adjusts a turn-off time of the backlight panel according to the startup time of the backlight panel. The liquid crystal display device of claim 1, wherein the backlight driving circuit fixes a closing time of the backlight panel. The liquid crystal display device of claim 1, wherein the environmental parameter detecting circuit comprises: a working time counter for calculating a continuous working time of the liquid crystal display device. The liquid crystal display device of claim 1, wherein the environmental parameter detecting circuit comprises: a controller, performing an arithmetic operation on the environmental parameter, and generating the adjustment signal. The liquid crystal display device of claim 1, wherein the environment parameter detecting circuit further comprises: a lookup table, recording an operation result of the arithmetic operation and a relative relationship of the adjustment signal, wherein the controller is configured according to the The result of the arithmetic operation is to perform a lookup operation on the lookup table, and thereby generate the adjustment signal. The liquid crystal display device of claim 1, wherein the backlight driving circuit adjusts a time difference between the startup time of the backlight panel and the vertical synchronization period according to the adjustment signal. The liquid crystal display device of claim 1, wherein the environmental parameter comprises at least one of temperature, humidity, and continuous operation time of the liquid crystal display device. A backlight adjustment method for a three-dimensional liquid crystal display device includes: detecting an environmental parameter of an environment to which the liquid crystal display device belongs, and generating an adjustment signal according to the environmental parameter; dynamically adjusting and starting according to the adjustment signal and a vertical synchronization period a startup time of a backlight panel of the liquid crystal display device; and a left eye image and a right eye image alternately receiving a display image according to the startup time. The backlight adjustment method of claim 9, wherein the step of generating the adjustment signal according to the environmental parameter comprises: performing an arithmetic operation on the environmental parameter, and generating the adjustment signal. The backlight adjustment method of claim 10, wherein the step of generating the adjustment signal according to the environmental parameter further comprises: providing a lookup table to record an operation result of the arithmetic operation and a relative relationship of the adjustment signal; The lookup table is searched according to the operation result of the arithmetic operation, and the adjustment signal is generated. The backlight adjustment method of claim 9, wherein the step of dynamically adjusting the startup time of the backlight panel of the liquid crystal display device according to the adjustment signal and the vertical synchronization period comprises: adjusting according to the adjustment signal The startup time of the backlight panel is different from the time during the vertical synchronization. The backlight adjustment method of claim 9, wherein the environmental parameter comprises at least one of temperature, humidity, and continuous operation time of the liquid crystal display device. The backlight adjustment method of claim 9, further comprising: adjusting a turn-off time of the backlight panel according to the startup time of the backlight panel. The backlight adjustment method of claim 9, further comprising: fixing a closing time of the backlight panel.