TWI778472B - Display apparatus having display panel and humidity detection method thereof - Google Patents

Abstract

A display apparatus having a display panel and a humidity detection method thereof are provided. The humidity detection method includes: displaying a test pattern on the display panel; projecting an incident light to the test pattern of the display panel by a light source for generating a diffraction light; and detecting the diffraction light by a light detector for obtaining humidity information of the display panel.

Description

Display device with display panel and humidity detection method thereof

The present invention relates to a humidity detection method, in particular to a humidity detection method of a display panel.

With the development of display technology, Liquid Crystal on Silicon (LCoS) panels have high-resolution display capabilities, so LCD on silicon panels have gradually become the mainstream in the design of automotive head-up displays. trend. The liquid crystal on silicon panel can modulate the phase of incident light through simple voltage control, thereby generating a stereoscopic holographic image. The stereoscopic holographic image can be used as a display image of a vehicle instrument panel. However, the phase modulation curve (ie, the characteristic curve of voltage versus phase) of the liquid crystal-on-silicon panel is easily shifted due to the influence of environmental conditions such as temperature and humidity. Especially when the liquid crystal on silicon panel is operated at a relatively high temperature or humidity, the display image of the liquid crystal on silicon panel will generate image noise due to the shift of the phase modulation curve, thereby resulting in poor display quality.

The invention provides a display device with a display panel and a humidity detection method thereof. The display device can correct the gamma curve of the display panel according to the humidity information of the display panel.

An embodiment of the present invention provides a humidity detection method for a display panel. The humidity detection method includes: displaying a test pattern by a display panel; projecting incident light to the test pattern of the display panel by a light source to generate diffracted light; and detecting the diffracted light by a light detector to obtain the humidity of the display panel News.

Another embodiment of the present invention provides a display device. The display device includes a light source, a display panel, a light detector and a controller. A light source is used to provide incident light. The display panel is used to display the test pattern. Incident light is projected onto the test pattern of the display panel to generate diffracted light. The photodetector is used to detect diffracted light to generate a detection result. The controller is coupled to the display panel and the light detector, and obtains humidity information of the display panel according to the detection result of the light detector.

Yet another embodiment of the present invention provides a display device. The display device includes a display panel, a temperature sensor, and a controller. The temperature sensor is used for sensing the temperature of the display panel to obtain temperature information. The controller is coupled to the display panel and the temperature sensor, and determines the humidity information of the display panel. The controller determines the gamma setting for the display panel based on the humidity information and the temperature information.

Based on the above, in various embodiments of the present invention, the display device can obtain the humidity information of the display panel by detecting the diffracted light generated by the display panel. The display device can also obtain the temperature information of the display panel through the temperature sensor. Therefore, the display devices according to the embodiments of the present invention can rely on the humidity information and the temperature information to instantly adjust the display panel's gamma setting. Since the gamma setting of the display panel can be adjusted in real time with the change of the operating conditions (temperature, humidity) of the display panel, the display screen of the display panel can maintain a good image quality.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

100,500: Display device

101,501: Light source

102,502: Display panel

103,503: Photodetector

104,504: Controller

105,505: Lookup table

106: Aperture

107: Lens

506: Temperature sensor

1011, 5011: Incident light

5021: Gamma Buffer

C1: -1st order diffracted light

C2: 0th order diffracted light

C3: +1st order diffracted light

curve 1: the first reference curve

curve 2: the second reference curve

curve 3: the third reference curve

DL: diffracted light

DL1: The first diffracted light component

DL2: Second diffracted light component

G11, G12, G13: Gamma parameters

G21, G22, G23: Gamma parameters

G31, G32, G33: Gamma parameters

GR: grating pattern

H1, H2, H3: Humidity value

P1: The first line of pixels

P2: The second line of pixels

P3: The third row of pixels

P4: Fourth row of pixels

P5: Fifth row of pixels

T1, T2, T3: temperature value

V1: The first driving voltage

V2: The second driving voltage

V3: The third driving voltage

V4: Fourth driving voltage

V5: Fifth driving voltage

S200, S210, S220, S600, S610, S620: method steps

1A is a schematic diagram of a circuit block of a display device according to an embodiment of the present invention.

FIG. 1B is a schematic diagram illustrating an optical path configuration of the display device 100 of FIG. 1A according to an embodiment of the present invention.

FIG. 2 is a schematic flowchart of a humidity detection method for a display panel according to an embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating humidity reference information built in the lookup table 105 of FIG. 1A according to an embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating generating a test pattern for the display panel 102 of FIG. 1A according to an embodiment of the present invention.

FIG. 5A is a schematic circuit block diagram of a display device according to another embodiment of the present invention.

FIG. 5B is a circuit block diagram illustrating the display device 500 of FIG. 5A according to an embodiment of the present invention.

FIG. 6 is a schematic flowchart of a gamma curve calibration method according to an embodiment of the present invention.

The term "coupled (or connected)" as used throughout this specification (including the scope of the application) may refer to any direct or indirect means of connection. For example, if it is described in the text that a first device is coupled (or connected) to a second device, it should be interpreted that the first device can be directly connected to the second device, or the first device can be connected to the second device through another device or some other device. indirectly connected to the second device by a connecting means. Also, where possible, elements/components/steps using the same reference numerals in the drawings and embodiments represent the same or similar parts. Elements/components/steps that use the same reference numerals or use the same terminology in different embodiments may refer to relative descriptions of each other.

1A is a schematic diagram of a circuit block of a display device according to an embodiment of the present invention. As shown in FIG. 1A , the display device 100 includes a light source 101 , a display panel 102 , a light detector 103 and a controller 104 . The display panel 102 has a plurality of pixels (not shown), and the display device 100 can drive pixels at different positions on the display panel 102 according to design requirements, so that the display panel 102 can display a specific test pattern (not shown). The test pattern may be a pixel pattern that causes diffraction of light waves, such as a grating pattern.

The light source 101 can provide incident light 1011 and project the incident light 1011 to a test pattern (not shown) displayed on the display panel 102 to generate diffracted light DL. The light detector 103 can generate a detection result by detecting the diffracted light DL. For example That is, FIG. 1B is a schematic diagram illustrating an optical path configuration of the display device 100 of FIG. 1A according to an embodiment of the present invention. In the embodiment of FIG. 1B , the display panel 102 can display the grating pattern GR as a test pattern. According to design requirements, the display panel 102 of FIG. 1B may be a Liquid Crystal on Silicon (LCoS) panel or other liquid crystal panels, and the light source 101 of FIG. 1B may be a light projector for projecting a laser beam.

When the light source 101 projects the incident light 1011 to the grating pattern GR of the display panel 102 , the display panel 102 will generate diffracted light DL. As shown in FIG. 1B , the diffracted light DL includes a first diffracted light component DL1 and a second diffracted light component DL2 , and the diffraction order of the second diffracted light component DL2 is higher than that of the first diffracted light component DL1 . In the embodiment of FIG. 1B , there is a higher correlation between the first diffracted light component DL1 and the second diffracted light component DL2 detected by the photodetector 103 . For example, the diffraction order of the first diffracted light component DL1 may include at least one of 0, 1, and -1, and the diffraction order of the second diffracted light component DL2 may include 3. In other words, the first diffracted light component DL1 may include at least one of -1st order diffracted light C1, 0th order diffracted light C2 and +1st order diffracted light C3, and the second diffracted light component DL2 may include 3rd order diffracted light .

As shown in FIG. 1B , a diaphragm 106 and a lens 107 are also arranged inside the display device 100 . The aperture 106 is disposed between the display panel 102 and the lens 107 . The aperture 106 can block the second diffracted light component DL2 and collect the first diffracted light component DL1 as the signal light for forming the virtual display image. The lens 107 can allow the first diffracted light component DL1 to be imaged outside the display device 100 and improve the imaging field of view. The second diffracted light component DL2 can be received by the photodetector 103 to detect the light intensity.

Referring to FIG. 1A again, the controller 104 is coupled to the photodetector 103 to obtain the humidity information of the display panel 102 according to the detection result of the photodetector 103 . For example, the display device 100 may be configured with the lookup table 105 . The look-up table 105 may be built with humidity reference information, such as correspondence data between the light intensity of the second diffracted light component DL2 and the humidity value of the display panel 102 . The controller 104 can obtain the light intensity of the second diffracted light component DL2 in the diffracted light DL by receiving the detection result of the light detector 103, and find the corresponding humidity value from the look-up table 105 for display Humidity information of the panel 102 . In this way, the controller 104 can adjust the gamma setting of the display panel 102 according to the humidity information of the display panel 102 to prevent the moisture inside the display panel 102 from affecting the image quality of the display screen.

It should be noted that, in the above embodiment, since the first diffracted light component DL1 is used as the signal light for forming the virtual display image, and the second diffracted light component DL2 detected by the photodetector 103 is used as the adjustment display The gamma setting of the panel is used to correct the light, so if the correlation between the first diffracted light component DL1 and the second diffracted light component DL2 is higher, the gamma curve of the display panel can be corrected more accurately. Since the correlation between the third-order diffracted light in the diffracted light DL and the first diffracted light component DL1 is relatively high, the embodiment of FIG. 1B selects the third-order diffracted light in the diffracted light DL as the second diffracted light component DL2 .

FIG. 2 is a schematic flowchart of a humidity detection method for a display panel according to an embodiment of the present invention. Referring to FIG. 1 and FIG. 2 , in step S200 , the display panel 102 may display the test pattern. In step S210, the light source 101 may project the incident light 1011 to the test pattern of the display panel 102 to generate diffracted light DL. when diffraction When the light DL is generated, the light detector 103 can detect the diffracted light DL in step S220, and provide the light intensity information of the diffracted light DL to the controller 104, so that the controller 104 can compare the light intensity information of the diffracted light DL to the controller 104. The humidity reference information in the table 105 is looked up to obtain the humidity information of the display panel 102 . The implementation details of step S200 , step S210 and step S220 can be inferred with reference to the related descriptions of the embodiments shown in FIG. 1A and FIG. 1B , and thus will not be repeated.

In other embodiments, the controller 104 of FIG. 1A can also adjust at least one driving voltage of the display panel 102 , and obtain the second diffracted light component DL2 in the diffracted light DL through the detection result provided by the photodetector 103 . , in order to further obtain the characteristic curve of voltage versus phase. In other words, during the adjustment period of the driving voltage, the controller 104 can obtain the voltage-phase characteristic curve according to the change of the light intensity caused by different driving voltages. According to the voltage-phase characteristic curve, the controller 104 can find the corresponding humidity value from the look-up table 105 as the humidity information of the display panel 102 .

In detail, the controller 104 can adjust at least one driving voltage of the display panel 102 so as to detect a plurality of light intensities of the second diffracted light component DL2 during the adjustment period of the driving voltage. The controller can respectively calculate a plurality of phase values corresponding to the light intensities (eg, calculate the phase values through a built-in conventional algorithm) according to the light intensities, and generate a voltage-to-phase characteristic curve according to the phase values. After the controller 104 generates the voltage-to-phase characteristic curve by adjusting the driving voltage of the display panel 102 , the controller 104 can compare the voltage-to-phase characteristic curve with the humidity reference information established in the look-up table 105 , in order to find out from lookup table 105 The humidity value corresponding to the voltage versus phase characteristic curve is used to determine the humidity state of the display panel 102 .

For example, the look-up table 105 of FIG. 1A may be pre-built with a plurality of voltage-to-phase reference curves under different humidity conditions, as the humidity reference information of the look-up table 105 . FIG. 3 is a schematic diagram illustrating humidity reference information built in the lookup table 105 of FIG. 1A according to an embodiment of the present invention. The vertical axis shown in FIG. 3 represents the phase, and the horizontal axis represents the voltage. In the embodiment of FIG. 3 , the humidity reference information of the look-up table 105 includes a first reference curve curve 1 , a second reference curve curve 2 and a third reference curve curve 3 . The first reference curve curve 1 corresponds to the humidity value H1, the second reference curve curve 2 corresponds to the humidity value H2, and the third reference curve curve 3 corresponds to the humidity value H3. The humidity values H1, H2, and H3 represent different humidity states, respectively.

The controller 104 can apply a larger driving voltage to some or all of the pixels of the display panel 102 to change the light intensity of the second diffracted light component DL2. The controller 104 can also apply a smaller driving voltage to some or all of the pixels of the display panel 102 to change the light intensity of the second diffracted light component DL2. After the controller 104 generates the voltage-to-phase characteristic curve by adjusting the driving voltage of the display panel 102 , the controller 104 can compare the voltage-to-phase characteristic curve with the reference curve in the look-up table 105 (ie the first reference curve curve 1. The second reference curve curve 2, the third reference curve curve 3) Compare one by one. Assuming that the voltage versus phase characteristic curve is highly correlated with the first reference curve curve 1 , the controller 104 can determine that the display panel 102 has a humidity value H1 . Similarly, if the correlation between the voltage-phase characteristic curve and the second reference curve curve 2 is relatively high, the controller 104 can determine The broken display panel 102 has a humidity value H2.

FIG. 4 is a schematic diagram illustrating generating a test pattern for the display panel 102 of FIG. 1A according to an embodiment of the present invention. As shown in FIG. 4 , the display panel 102 may display a grating pattern GR as a test pattern. The grating pattern GR includes pixels P1 in a first row, pixels P2 in a second row, pixels P3 in a third row, pixels P4 in a fourth row, and pixels P5 in a fifth row, which are adjacent to each other. Adjacent line pixels in the grating pattern GR can be driven by different driving voltages (ie V1, V2, V3, V4, V5). For example, the first driving voltage V1 of the pixels P1 in the first row may be different from the second driving voltage V2 of the pixels P2 in the second row, and the second driving voltage V2 of the pixels P2 in the second row may be different from the pixels in the third row. The third driving voltage V3 of P3, and so on. In the embodiment of FIG. 4 , the first driving voltage V1 of the pixels P1 in the first row, the third driving voltage V3 of the pixels P3 in the third row, and the fifth driving voltage V5 of the pixels P5 in the fifth row may be greater than those in the second row. The second driving voltage V2 of the pixel P2 and the fourth driving voltage V4 of the pixel P4 in the fourth row (ie, V1, V3, and V5 are all greater than V2 and V4). Therefore, the display panel 102 can display the grating pattern GR of "bright/dark/bright/dark/bright".

Referring to FIG. 1 and FIG. 4 , it is assumed that the first driving voltage V1 is greater than the second driving voltage V2 . The controller 104 can adjust the voltage difference between the first driving voltage V1 and the second driving voltage V2, so as to know the driving voltage of the second diffracted light component DL2 of the diffracted light DL through the detection result provided by the photodetector 103. Adjust multiple light intensities in the period. For example, the controller 104 may not adjust the first driving voltage V1, and may increase the second driving voltage V2, so that the voltage difference between the first driving voltage V1 and the second driving voltage V2 gradually decreases. The controller 104 may also not adjust the second driving power voltage V2, and reduce the first driving voltage V1, so that the voltage difference between the first driving voltage V1 and the second driving voltage V2 gradually decreases.

Since the voltage difference between the first driving voltage V1 and the second driving voltage V2 is changed, the brightness of the grating pattern GR is also changed, thereby changing the light intensity of the second diffracted light component DL2. In other words, each time the voltage difference between the first driving voltage V1 and the second driving voltage V2 is changed, a corresponding light intensity of the second diffracted light component DL2 is generated. Therefore, during the adjustment period of the voltage difference between the first driving voltage V1 and the second driving voltage V2, the photodetector 103 can detect a plurality of light intensities of the second diffracted light component DL2.

The controller 104 may calculate a plurality of phase values corresponding to the plurality of light intensities detected by the light detector 103 respectively (for example, calculating the phase values through a built-in conventional algorithm). The controller 104 can then generate a voltage versus phase characteristic curve according to these phase values.

For example, it is assumed that the look-up table 105 has been built with a voltage-versus-phase reference curve as shown in FIG. 3 . The controller 104 may compare the voltage versus phase characteristic curve with the reference curves in the lookup table 105 (ie, the first reference curve curve 1 , the second reference curve curve 2 , and the third reference curve curve 3 ) one by one. Assuming that the voltage versus phase characteristic curve is highly correlated with the first reference curve curve 1 , the controller 104 can determine that the display panel 102 has a humidity value H1 . Similarly, if the correlation between the voltage versus phase characteristic curve and the second reference curve curve 2 is relatively high, the controller 104 can determine that the display panel 102 has a humidity value H2.

5A is a circuit diagram of a display device according to another embodiment of the present invention Block diagram. As shown in FIG. 5A , the display device 500 includes a display panel 502 , a controller 504 and a temperature sensor 506 . The display panel 502 has a plurality of pixels (not shown), and the display device 500 can drive pixels at different positions on the display panel 502 according to design requirements, so that the display panel 502 can display a specific test pattern. The temperature sensor 506 may be disposed on the surface or inside of the display panel 502 to sense the temperature of the display panel 502 . The controller 504 is coupled to the display panel 502 and the temperature sensor 506 . The controller 504 can determine the humidity information of the display panel 502 . The following describes how the controller 504 determines the humidity information of the display panel 502 with reference to FIG. 5B .

FIG. 5B is a circuit block diagram illustrating the display device 500 of FIG. 5A according to an embodiment of the present invention. As shown in FIG. 5B , the display device 500 further includes a light source 501 , a light detector 503 and a look-up table 505 . The light source 501 may provide incident light 5011 to the display panel 502 . The display panel 502 can display test patterns (not shown). The test pattern is, for example, a grating pattern that can cause diffraction of light waves. When the light source 501 projects the incident light 5011 to the test pattern (not shown) of the display panel 502 , the display panel 502 will generate diffracted light DL. The diffracted light DL includes a first diffracted light component DL1 and a second diffracted light component DL2, and the diffraction order of the second diffracted light component DL2 is higher than that of the first diffracted light component DL1.

The light detector 503 can detect the second diffracted light component DL2 of the diffracted light DL, and provide the detection result to the controller 504 . The controller 504 can obtain the humidity information of the display panel 502 according to the detection result. For example, the controller 504 can directly find the corresponding humidity value from the lookup table 505 according to the light intensity of the second diffracted light component DL2 as The humidity information of the display panel 502 is displayed. Controller 504 can also The voltage versus phase characteristic curve related to the second diffracted light component DL2 is obtained by adjusting the driving voltage of the display panel 502 . According to the voltage-phase characteristic curve, the controller 504 can find the corresponding humidity value from the look-up table 505 as the humidity information of the display panel 502 . The implementation details of the controller 504 obtaining the humidity information of the display panel 502 through the look-up table 505 can be deduced by referring to the related descriptions of FIGS.

Referring again to FIG. 5B , the display panel 502 further includes a gamma buffer 5021 . The gamma buffer 5021 can store the gamma settings of the display panel 502 . For example, the gamma buffer 5021 can store the original gamma parameters of the display panel 502 for future calibration. In the embodiment of FIG. 5B , the temperature sensor 506 is disposed inside the display panel 502 to obtain temperature information of the display panel 502 . The controller 504 may determine the gamma setting for the display panel 502 according to the humidity information of the display panel 502 and the temperature information of the display panel 502 .

In some embodiments, the controller 504 may receive the temperature information provided by the temperature sensor 506 to adjust the gamma setting of the display panel 502 according to the temperature information of the display panel 502 . In other embodiments, the controller 504 can also receive the detection result provided by the light detector 503, and find out the humidity value corresponding to the detection result through the lookup table 505, thereby obtaining the humidity value of the display panel 502. Humidity information, and then adjust the gamma setting of the display panel 502 according to the humidity information of the display panel 502 . In addition, the controller 504 can also adjust the gamma setting of the display panel 502 according to the humidity information of the display panel 502 and the temperature information of the display panel 502 at the same time.

For example, the lookup table 505 of FIG. 5B can be constructed with the following table 1 displayed gamma information. T1, T2, and T3 shown in Table 1 represent different temperature values, respectively. H1, H2 and H3 shown in Table 1 respectively represent different humidity values. G11 , G12 , G13 , G21 , G22 , G23 , G31 , G32 , and G33 shown in Table 1 represent the gamma parameters of the display panel 502 operating under a specific temperature and a specific humidity, respectively. For example, when the display panel 502 operates at the humidity value H1 and the temperature value T1, the display panel 502 has a gamma parameter G11. When the display panel 502 operates at the humidity value H1 and the temperature value T2, the display panel 502 has a gamma parameter G12, and so on.

Referring to FIG. 5B again, it is assumed that the controller 504 determines that the display panel 502 has the humidity value H1 according to the detection result of the light detector 503 , and the controller 504 obtains the display according to the detection result of the temperature sensor 506 Panel 502 has a temperature value T2. According to the humidity value H1 and the temperature value T2, the controller 504 can determine that the display panel 502 has the gamma parameter G12 through the lookup table 505 (as shown in Table 1).

Since the gamma buffer 5021 stores the original gamma parameters of the display panel 502 , the controller 504 can obtain the original gamma parameters of the display panel 502 through the gamma buffer 5021 . The controller 504 can adjust the gamma parameter G12 according to the original gamma parameter, so as to correct the gamma curve of the display panel 502 at the humidity value H1 and the temperature value T2 to the original gamma curve. Through the above calibration method, the controller 504 can adjust the display surface in real time according to the humidity information and temperature information of the display panel 502 board's gamma setting. Therefore, the display panel 502 can maintain good display quality without being affected by operating conditions (temperature, humidity).

FIG. 6 is a schematic flowchart of a gamma curve calibration method according to an embodiment of the present invention. Referring to FIG. 5A and FIG. 6 , in step S600 , the controller 504 can determine the humidity information of the display panel 502 . In step S610, the temperature sensor 506 may sense the temperature of the display panel 502 to obtain temperature information. After the controller 504 receives the temperature information provided by the temperature sensor 506, the controller 504 may determine the gamma setting for the display panel 502 according to the humidity information and the temperature information in step S620. The implementation details of step S600 , step S610 and step S620 can be inferred with reference to the related descriptions of the embodiments shown in FIG. 5A and FIG. 5B , and thus will not be repeated.

To sum up, in various embodiments of the present invention, the display device can obtain the humidity information of the display panel by detecting the diffracted light generated by the display panel. The display device can also obtain the temperature information of the display panel through the temperature sensor. Therefore, the display device according to the embodiments of the present invention can adjust the gamma setting of the display panel in real time according to the humidity information and the temperature information. Since the gamma setting of the display panel can be adjusted in real time with the change of the operating conditions (temperature, humidity) of the display panel, the display screen of the display panel can maintain a good image quality.

Although the present invention has been disclosed above by the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the scope of the appended patent application.

S200, S210, S220: method steps

Claims (20)

A humidity detection method for a display panel, comprising: displaying a test pattern for generating diffracted light by the display panel; projecting an incident light to the test pattern of the display panel by a light source to generate the diffracted light; and The diffracted light is detected by a light detector to obtain a humidity information of the display panel. The humidity detection method according to claim 1, wherein the step of detecting the diffracted light comprises: detecting a light intensity of the diffracted light; and finding a look-up table according to the light intensity of the diffracted light A corresponding humidity value is generated as the humidity information of the display panel. The humidity detection method according to claim 1, wherein the step of detecting the diffracted light comprises: adjusting at least one driving voltage of the display panel and detecting the light intensity of the diffracted light to obtain a voltage-to-phase characteristic curve; and according to the voltage versus phase characteristic curve, find out a corresponding humidity value from a look-up table as the humidity information of the display panel. The humidity detection method according to claim 3, wherein the step of obtaining the voltage versus phase characteristic curve comprises: adjusting the at least one driving voltage of the display panel so as to detect the diffracted light during a driving voltage adjustment period multiple light intensities; A plurality of phase values corresponding to the light intensities are respectively calculated according to the light intensities; and the voltage-to-phase characteristic curve is generated according to the phase values. The humidity detection method of claim 1, wherein the display panel comprises a liquid crystal panel on silicon. The humidity detection method according to claim 1, wherein the diffracted light comprises a first diffracted light component and a second diffracted light component, and the diffraction order of the second diffracted light component is higher than that of the first diffracted light component The first diffracted light component is used to image the outside of a display device having the display panel, and the second diffracted light component is used to provide the photodetector to detect light intensity Measurement. The humidity detection method according to claim 6, wherein the diffraction order of the first diffracted light component includes at least one of 0, 1, and -1, and the diffraction order of the second diffracted light component The order of projections includes 3. The humidity detection method of claim 1, wherein the test pattern comprises a grating pattern. The humidity detection method of claim 8, wherein the grating pattern comprises a first line of pixels and a second line of pixels adjacent to each other, and a first driving voltage of the first line of pixels is different from the A second driving voltage of the second row of pixels, wherein the step of detecting the diffracted light includes: adjusting a voltage difference between the first driving voltage and the second driving voltage, so as to detect that the diffracted light is in a plurality of light intensities in a driving voltage adjustment period; according to the light intensities, respectively calculating a plurality of phase values corresponding to the light intensities; generating a voltage-to-phase characteristic curve according to the phase values; and finding a corresponding humidity value from a look-up table as the humidity information of the display panel according to the voltage-to-phase characteristic curve. A display device, comprising: a light source for providing an incident light; a display panel for displaying a test pattern for generating diffracted light, wherein the incident light is projected on the test pattern of the display panel to generate the diffracted light; a photodetector for detecting the diffracted light to generate a detection result; and a controller coupled to the display panel and the photodetector for according to the photodetector The detection result is obtained to obtain a humidity information of the display panel. The display device of claim 10, wherein the controller receives the detection result of the photodetector to obtain the light intensity of the diffracted light, and the controller selects the light intensity from a diffracted light according to the light intensity of the diffracted light A corresponding humidity value is found in the look-up table as the humidity information of the display panel. The display device according to claim 10, wherein the controller adjusts at least one driving voltage of the display panel, and obtains the light intensity of the diffracted light according to the detection result provided by the photodetector to obtain a a voltage-to-phase characteristic curve; and the controller finds a corresponding humidity value from a look-up table as the humidity information of the display panel according to the voltage-to-phase characteristic curve. The display device of claim 12, wherein the controller adjusts the at least one driving voltage of the display panel so as to pass the The detection result provided by the light detector is used to obtain a plurality of light intensities of the diffracted light during a driving voltage adjustment period of the at least one driving voltage; the controller calculates the corresponding light intensities according to the light intensities. a plurality of phase values of the intensity; and the controller generates the voltage-to-phase characteristic curve according to the phase values. The display device of claim 10, wherein the display panel comprises a liquid crystal on silicon panel. The display device according to claim 10, wherein the diffracted light comprises a first diffracted light component and a second diffracted light component, and the diffraction order of the second diffracted light component is higher than that of the first diffracted light component The first diffracted light component is used to image the outside of the display device, and the second diffracted light component is used to provide the light detector to detect the light intensity. The display device of claim 15, wherein the diffraction order of the first diffracted light component includes at least one of 0, 1, and -1, and the diffraction order of the second diffracted light component The number includes 3. The display device of claim 15, further comprising: an aperture for blocking the second diffracted light component. The display device of claim 17, further comprising: a lens for enhancing an imaging field of view, wherein the aperture is disposed between the display panel and the lens. The display device of claim 10, wherein the test pattern comprises a grating pattern. The display device of claim 19, wherein the grating pattern comprises a first row of pixels and a second row of pixels adjacent to each other, and a first driving voltage of the first row of pixels is different from the second row of pixels a second driving voltage of the pixel; the controller adjusts a voltage difference between the first driving voltage and the second driving voltage, so as to know the winding through the detection result provided by the photodetector emit a plurality of light intensities in a driving voltage adjustment period; the controller calculates a plurality of phase values corresponding to the light intensities according to the light intensities; the controller generates a voltage-to-phase characteristic according to the phase values curve; and the controller finds a corresponding humidity value from a look-up table as the humidity information of the display panel according to the voltage versus phase characteristic curve.

Images