TWI470599B - Optical measurement system - Google Patents

Description

Optical measurement system

This invention relates to an optical metrology system, and more particularly to an optical metrology system that can measure the flicker of a display component.

With the rapid advancement of optoelectronic technology and semiconductor technology, flat panel displays such as liquid crystal displays (LCDs) have flourished in recent years. Due to the high space utilization, low power consumption, no radiation and low electromagnetic interference of liquid crystal displays, liquid crystal displays have become the mainstream of the current flat panel display market. Moreover, the liquid crystal display panel adjusts the light transmittance and the reflectance of the light source by controlling the rotation angle of the liquid crystal to display an image, and the rotation angle of the liquid crystal molecules is caused by a voltage difference between a common voltage across the liquid crystal layer and a pixel voltage of the pixel electrode, and an electric field direction. Determined.

Generally, each pixel electrode receives a corresponding pixel voltage through a corresponding active component, but the feedthrough voltage of the active component affects the voltage level of the pixel voltage received by the pixel electrode, so that the liquid crystal display panel may have a screen flicker. The phenomenon. In order to compensate for the influence of the feedthrough voltage, the common voltage of the liquid crystal display panel can be adjusted correspondingly to reduce or eliminate the phenomenon of flickering of the screen. Moreover, in order to confirm the effect of adjusting the common voltage, the brightness displayed by the liquid crystal display panel is measured by the light sensor, and the brightness curve of the liquid crystal display panel is drawn according to the brightness measured by the light sensor to transmit the brightness curve. Confirm the effect of adjusting the common voltage.

However, the screen update rate of the liquid crystal display panel is generally 60 Hz (Hz) In the above, the brightness detection rate of the photo sensor is several times higher than the picture update rate of the liquid crystal display panel, so that the brightness curve of the liquid crystal display panel can be correctly drawn. However, the light sensor with high brightness capture rate has to pay a higher hardware cost, which in turn affects the overall manufacturing cost of the liquid crystal display panel.

The invention provides an optical measuring system, wherein the sum display panel displays the brightness of a preset time as a corresponding brightness value, so that the optimal common voltage of the display panel can be completed by the light sensor of the low brightness capturing rate. The measurement further reduces the overall manufacturing cost of the display panel.

The invention provides an optical measuring system comprising a light sensor and a driving circuit. The light sensor is configured to detect the brightness of a test image displayed on a display panel. The driving circuit is coupled to the display panel and the photo sensor, and is configured to control the display panel to display the plurality of different common voltages in sequence, and the driving circuit sequentially obtains a plurality of brightness values from the photosensor, and determines the brightness values according to the brightness values. The display panel corresponds to an optimal common voltage that is not blinking, wherein the brightness values are respectively the sum of the brightness of the display panel for a preset time.

In an embodiment of the invention, the driving circuit sequentially emits a plurality of sampling signals, and the optical sensor starts to receive each sampling signal, and starts to display the display panel for a preset time. The brightness is taken as the corresponding brightness value.

In an embodiment of the present invention, the driving circuit draws a plurality of brightness curves corresponding to the common voltages of the display panel according to the brightness values, and calculates a relative relationship between the common voltages and the degree of flicker according to the brightness curves. And the optimal common voltage for the display panel corresponding to the non-flashing according to the relative relationship.

In an embodiment of the invention, the photo sensor is composed of a plurality of matrix-arranged photosensitive pixels, and the driving circuit calculates an optimal reference common voltage distribution of the display panel according to the brightness values corresponding to the photosensitive pixels, and The best reference common voltage distribution determines the optimum common voltage for the display panel that does not flash.

In an embodiment of the invention, the driving circuit sequentially sends a plurality of sampling signals, and the photo sensor starts each sampling signal when receiving each sampling signal, and sums each photosensitive pixel within a preset time. The sensed brightness of the display panel is displayed as the corresponding brightness value.

In an embodiment of the invention, the preset time is greater than or equal to an interval between the sampling signals.

In an embodiment of the present invention, the driving circuit draws a plurality of brightness curves corresponding to the common voltages in the portions of the display panel corresponding to each of the photosensitive pixels according to the brightness values corresponding to each of the photosensitive pixels, and calculates each brightness curve according to the brightness curves. The relative relationship between the common voltage and the degree of flicker in the portion of the display panel corresponding to the photosensitive pixels, and the optimal reference common voltage distribution of the display panel is calculated according to the relative relationships corresponding to the photosensitive pixels.

In an embodiment of the invention, the optimal common voltage is the best reference common voltage corresponding to the central region of the display panel.

In one embodiment of the invention, the optimal common voltage is an average of the best reference common voltage distribution.

Based on the above, the optical measuring system of the embodiment of the invention has light sensing The brightness of the display panel is sensed for a longer period of time, so the sensed brightness is higher and the brightness capture rate can be lowered. Thereby, the overall manufacturing cost of the display panel can be reduced.

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

1 is a system diagram of an optical measurement system and a display panel in accordance with an embodiment of the present invention. Referring to FIG. 1, in the embodiment, the display panel is exemplified by a germanium-based liquid crystal (LCOS) display panel 13. The 矽-based liquid crystal display panel 13 is disposed in the projection device 10, and the 矽-based liquid crystal display panel 13 transmits the test image IT through the projection light source PL provided by the reflective light source device 11.

The optical measurement system 100 includes a drive circuit 110 and a light sensor 120. The light sensor 120 is configured to detect the brightness of the test image IT displayed by the liquid crystal display panel 13 and output a plurality of brightness values BV, wherein the brightness values are respectively displayed by the liquid crystal display panel 13 for a preset time. The sum of the brightness. The driving circuit 110 is coupled to the 矽-based liquid crystal display panel 13 and the photo sensor 110. Here, the driving circuit 110 can control the 矽-based liquid crystal display panel 13 to sequentially display at a plurality of different common voltages. Moreover, the driving circuit 120 sequentially sends a plurality of sampling signals SSA to the photo sensor 120, and the photo sensor 120 sequentially responds to the corresponding brightness value BV corresponding to the sampling signals SSA, so that the driving circuit 120 is self-photosensitive. The device 120 sequentially obtains the brightness values BV, wherein the brightness values BV are respectively corresponding to different common voltages.

Then, since the brightness values BV are respectively corresponding to different common voltages, the driving circuit 110 can understand the degree of flicker at different common voltages according to the brightness values BV, whereby the driving circuit 110 can be determined according to the degree of flicker under different common voltages. The base liquid crystal display panel 13 corresponds to an optimum common voltage that is not blinking. In addition, in this embodiment, the preset time may be greater than the interval between the sampling signals SSA, so the light sensor 120 may have more time to sense the brightness of the test image IT (ie, the 矽-based liquid crystal display) The brightness displayed by the panel 13 is such that the brightness sensed by the photo sensor 120 is higher.

FIG. 2 is a schematic diagram of the luminance value extraction according to an embodiment of the invention. Referring to FIG. 1 and FIG. 2 , in the embodiment, the driving circuit 110 sequentially sends a plurality of sampling signals (such as SSA1 S SSA4 ) to the photo sensor 120 . When receiving each sampling signal (such as SSA1~SSA4), the light sensor 120 starts to receive each sampling signal (such as SSA1~SSA4), and sums the liquid crystal in the preset time (such as TP1~TP3). The brightness displayed on the display panel 13 is used as a corresponding brightness value (for example, BV1 to BV3).

For example, when receiving the sampling signal SSA1, the photo sensor 120 starts from the negative edge of the sampling signal SSA1 and sums the brightness displayed by the 矽-based liquid crystal display panel 13 within the preset time TP1 (ie, the test image IT The brightness is as the brightness value BV1, wherein the preset time TP1 is greater than the interval time between the sampling signals SSA1 and SSA2; when receiving the sampling signal SSA2, the light sensor 120 starts from the negative edge of the sampling signal SSA2, and the preset is preset. The brightness displayed by the 矽-based liquid crystal display panel 13 in the time TP2 (ie, the brightness of the test image IT) is taken as the brightness value BV2, wherein the preset time TP2 It is greater than the interval between the sampling signals SSA2 and SSA3, and the rest can be deduced by analogy, and will not be described here.

In addition, in this embodiment, the negative edge of the sampling signal (such as SSA1~SSA4) is taken as the starting point, but in other embodiments, the positive edge of the sampling signal (such as SSA1~SSA4) can be used as the starting point. Depending on the circuit design of the photo sensor 120, the embodiment of the present invention is not limited thereto.

FIG. 3 is a schematic diagram of a brightness curve of FIG. 1 according to an embodiment of the invention. FIG. Referring to FIG. 1 to FIG. 3, in the embodiment, after receiving sufficient brightness values (such as BV1~BV3), the driving circuit 110 can according to the time points corresponding to the brightness values of each brightness value (such as BV1~BV3) and Corresponding common voltages depict the brightness curve for each common voltage. In other words, in the luminance values (such as BV1 to BV3) corresponding to the same common voltage, the luminance values respectively indicated according to the corresponding time points. Taking the brightness values BV1 to BV3 as an example, according to the corresponding time points, the brightness values BV1, BV2, and BV3 are sequentially labeled, thereby drawing a brightness curve of the common voltage. Moreover, after the brightness curves corresponding to the common voltages are respectively completed, the degree of flicker corresponding to each common voltage can be calculated through the brightness curve. In addition, if the interval between sampling signals (such as SSA1~SSA4) is shorter, the closer the interval of brightness values (such as BV1~BV3) is; if the interval between sampling signals (such as SSA1~SSA4) is longer, the brightness value ( The farther apart, such as BV1~BV3).

4 is a schematic diagram of the comparison of the common voltage and the degree of flicker in FIG. 1 according to an embodiment of the invention. Referring to FIG. 1 to FIG. 4, in the embodiment, in calculating the degree of flicker corresponding to each common voltage, the driving circuit 110 can calculate the common voltage according to the respective flicker degrees of the common voltages. A relative relationship with the degree of flicker, and the relationship curve 410 can be drawn in accordance with this relative relationship. Among them, the degree of flicker is marked according to the relative size. Moreover, along the relationship curve 410, a common voltage corresponding to the degree of flicker of 0 (ie, corresponding to no flicker) can be found (as indicated by the common voltage OPC, here, for example, 0.49 volts).

In an example of the present invention, the photo sensor 120 can sum the total brightness of the test image IT (that is, the brightness displayed by the 矽-based liquid crystal display panel 13) in a preset time as the brightness value BV, that is, light. When receiving a sampling signal SSA, the sensor 120 will reply a brightness value BV. At this time, the driving circuit 110 can obtain the relative relationship between the common voltage and the degree of flicker according to the teachings of the embodiment of FIG. 2 to FIG. 4 (as shown by the relationship curve 410), and the corresponding common voltage OPC corresponding to the degree of flickering is 0. The optimum common voltage corresponding to the NMOS-based liquid crystal display panel 13.

In the above embodiment, the photo sensor 120 may be composed of a single photosensitive pixel, but in another embodiment of the present invention, the photo sensor 120 may be composed of a plurality of photosensitive pixels. In the case where the photo sensor 120 is composed of a plurality of matrix-arranged photosensitive pixels, the photo sensor 120 can sum up the portion of the test image IT sensed by the single photosensitive pixel (that is, the partial 矽-based liquid crystal display panel 13 The sum of the displayed brightness is the brightness value BV, that is, when the photo sensor 120 receives a sampling signal SSA, it will reply a plurality of brightness values BV, wherein the number of brightness values BV corresponds to the light sensing The number of photosensitive pixels of the device 120.

At this time, according to the teachings of the embodiment of FIG. 2 to FIG. 4, the driving circuit 110 can describe each photosensitive light according to the brightness values BV corresponding to each photosensitive pixel. A plurality of brightness curves corresponding to different common voltages (as shown in FIG. 3 ) are respectively corresponding to the portions of the 矽-based liquid crystal display panel 13 corresponding to the pixels, and the 矽-based liquid crystal display panel 13 corresponding to each of the photosensitive pixels can be calculated according to the brightness curves. The relative relationship between the different common voltages and the degree of flicker in the portion (as shown by the relationship curve 410). According to the relative relationship between different common voltages and the degree of flicker in the portion of the 矽-based liquid crystal display panel 13 corresponding to each photosensitive pixel, the driving circuit 110 can find the most corresponding portion of the 矽-based liquid crystal display panel 13 corresponding to each photosensitive pixel. The common voltage (i.e., the best reference common voltage) is used, whereby the optimum reference common voltage distribution of the NMOS-based liquid crystal display panel 13 can be calculated.

FIG. 5 is a schematic diagram of the best reference common voltage distribution of the display panel according to an embodiment of the invention. Referring to FIG. 1 to FIG. 5 , in the embodiment, the best reference common voltage distribution 500 corresponds to the 矽-based liquid crystal display panel 13 , and the optimal reference common voltage distribution 500 is roughly divided into three regions 510 , 520 , and 530 . The area AP is a portion of the 矽-based liquid crystal display panel 13 corresponding to each photosensitive pixel. In the case of a single area AP, the driving circuit 110 can calculate a plurality of brightness curves corresponding to different common voltages according to the brightness value BV provided by the corresponding photosensitive pixels (as shown in FIG. 3), and then calculate different according to the brightness curves. The relative relationship between the common voltage and the degree of flicker (as shown by relationship 410).

Referring to the best reference common voltage distribution 500, the corresponding best reference common voltages in the region 510 are substantially the same, and the corresponding best reference common voltages in the region 530 are substantially the same, but the best reference corresponding to the region 510 is common. The voltage is different from the best reference common power corresponding to the area 530 Pressure. The optimal reference common voltage corresponding to the region 520 is gradually changed, and is between the optimal reference common voltage corresponding to the region 510 and the optimal reference common voltage corresponding to the region 530.

In general, the 矽-based liquid crystal display panel 13 receives a common voltage, that is, the common voltage corresponding to the 矽-based liquid crystal display panel 13 is one, so the driving circuit 110 determines the 参考-based liquid crystal according to the optimal reference common voltage distribution 500. An optimum common voltage of the display panel 13.

In an embodiment of the present invention, the optimal common voltage of the NMOS-based liquid crystal display panel 13 may be an average value of the best reference common voltage distribution 500, that is, the sum of each optimal reference common voltage multiplied by the corresponding area. The area of the display area of the 矽-based liquid crystal display panel 13 is divided.

In an embodiment of the present invention, since the central portion of the image is the main viewing portion, the optimal reference common voltage corresponding to the central region (corresponding to the region 530) of the 液晶-based liquid crystal display panel 13 can be used as the 矽-based liquid crystal display. The optimum common voltage of panel 13.

FIG. 6 is a schematic diagram of a system of an optical measurement system and a display panel according to another embodiment of the present invention. Referring to FIG. 1 and FIG. 6 , in the embodiment, the display panel is exemplified by a thin film transistor (TFT) liquid crystal display panel 20 , wherein the thin film transistor liquid crystal display panel 20 can directly display the test image IT. The manner in which the optical measuring system 100 measures the optimal common voltage of the thin film transistor liquid crystal display panel 20 is substantially the same as the method of measuring the optimal common voltage of the liquid crystal display panel 13 , and can also refer to FIG. 1 to FIG. 5 . The teachings shown in the embodiments are not described here.

In summary, the optical measurement system of the embodiment of the invention has optical sensing The brightness of the display panel is sensed for a longer period of time, so the sensed brightness is higher and the brightness capture rate can be lowered. Thereby, the overall manufacturing cost of the display panel can be reduced.

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.

10‧‧‧Projector

100‧‧‧Optical measurement system

11‧‧‧Light source device

110‧‧‧Drive circuit

120‧‧‧Light sensor

13‧‧‧矽-based LCD panel

20‧‧‧Thin-film LCD panel

410‧‧‧ relationship curve

500‧‧‧Best reference common voltage distribution

510, 520, 530, AP‧‧‧ areas

BV, BV1~BV3‧‧‧ brightness value

IT‧‧‧ test image

OPC‧‧‧Common voltage

PL‧‧‧projection light source

SSA, SSA1~SSA4‧‧‧ sampling signal

TP1~TP3‧‧‧Preset time

1 is a system diagram of an optical measurement system and a display panel in accordance with an embodiment of the present invention.

FIG. 2 is a schematic diagram of the luminance value extraction according to an embodiment of the invention.

FIG. 3 is a schematic diagram of a brightness curve of FIG. 1 according to an embodiment of the invention. FIG.

4 is a schematic diagram of the comparison of the common voltage and the degree of flicker in FIG. 1 according to an embodiment of the invention.

FIG. 5 is a schematic diagram of the best reference common voltage distribution of the display panel according to an embodiment of the invention.

FIG. 6 is a schematic diagram of a system of an optical measurement system and a display panel according to another embodiment of the present invention.

10‧‧‧Projector

100‧‧‧Optical measurement system

11‧‧‧Light source device

110‧‧‧Drive circuit

120‧‧‧Light sensor

13‧‧‧矽-based LCD panel

BV‧‧‧ brightness value

IT‧‧‧ test image

SSA‧‧‧Sampling signal

Claims (9)

An optical measuring system includes: a light sensor for detecting brightness of a test image displayed on a display panel; and a driving circuit coupled to the display panel and the light sensor for controlling The display panel sequentially displays a plurality of different common voltages, and the driving circuit sequentially obtains a plurality of brightness values from the light sensor, and determines, according to the brightness values, a best common corresponding to the display panel that is not blinking. a voltage, wherein the brightness values respectively display a brightness sum of a preset time of the display panel, and the driving circuit sequentially sends a plurality of sampling signals, and the photo sensor receives each of the sampling signals to receive At the beginning of each of the sampling signals, the brightness displayed by the display panel in the preset time is taken as the corresponding brightness value. The optical measuring system of claim 1, wherein the preset time is greater than an interval between the sampling signals. The optical measuring system of claim 1, wherein the driving circuit draws a plurality of brightness curves corresponding to the common voltages of the display panel according to the brightness values, and calculates the common values according to the brightness curves. a relative relationship between the voltage and the degree of flicker, and determining the optimal common voltage corresponding to the non-flashing of the display panel according to the relative relationship. The optical measuring system of claim 1, wherein the optical sensor is formed by a plurality of matrix-arranged photosensitive pixels, and the driving circuit calculates the display according to the brightness values corresponding to the photosensitive pixels. An optimal reference common voltage distribution of the panel, and a common reference according to the best reference The pressure distribution determines that the display panel corresponds to the optimum common voltage that is not blinking. The optical measuring system of claim 4, wherein the driving circuit sequentially sends a plurality of sampling signals, and the photo sensor receives each of the sampling signals to receive each of the sampling signals. The sampling signal starts to sum the brightness displayed by the display panel sensed by each of the photosensitive pixels in the preset time as a corresponding brightness value. The optical measuring system of claim 5, wherein the preset time is greater than or equal to an interval time between the sampling signals. The optical measuring system of claim 4, wherein the driving circuit respectively corresponding to each of the photosensitive pixels corresponding to the display panel corresponding to the brightness values corresponding to each of the photosensitive pixels a plurality of brightness curves of the common voltage, and calculating, according to the brightness curves, a relative relationship between the common voltages and the degree of flicker in the portion of the display panel corresponding to each of the photosensitive pixels, according to the corresponding pixels The relative reference common voltage distribution of the display panel is calculated for the relative relationship. The optical measuring system of claim 4, wherein the optimal common voltage is an optimal reference common voltage corresponding to a central region of the display panel. The optical metrology system of claim 4, wherein the optimal common voltage is an average of the best reference common voltage distribution.