The present invention relates to a cholesterol liquid crystal display and a driving method thereof, and in particular, to a cholesteric liquid crystal display and its driving method that uses a variety of high-frequency bands to improve contrast and increase reflectivity to enhance the user's viewing experience when the display is within a unit time in the Non-Selection state.
Currently, the prevalent method for controlling cholesteric liquid crystal displays is through a Pulse Modulation (PM) driving mode. This mode encompasses Pulse Width Modulation (PWM), Dynamic Drive Scheme (DDS) driving modes, and other compound curve driving modes. In the PWM driving mode, there are two stages: Selection stage and Non-Selection stage. The DDS driver mode comprises four stages: Prepare stage, Selection stage, Evo stage, and Non-Selection stage. Besides, the compound curve driving mode consists of three stages: Manipulation stage, Selection stage, and Non-Selection stage. In the light, in all PM driving modes, while the Non-Selection stage is implemented, the image effect of the cholesteric liquid crystal display will be adversely affected.
In the prior art, a cholesteric liquid crystal display comprises upper and lower substrates with electrodes arranged on them, and the electrode directions on the upper and lower substrates intersect. One electrode functions as the COM electrode, and the other as the SEG electrode. The voltage supplied to the SEG electrode comprises both the bright state voltage and the dark state voltage. On the other hand, the voltage supplied to the COM electrode includes two kinds of voltages during both the Selection stage and the Non-Selection stage. This enables the application of different liquid crystal voltages to various areas during screen refresh resulting in the display of different color levels Refer to
As shown in
Therefore, to enhance the user's viewing experience and adjust the contrast and reflectivity of the cholesteric liquid crystal display, it is imperative to develop optimal technical methods to address the aforementioned issues.
The objective of the present invention is to enhance the display effect of a cholesteric liquid crystal display and its driving method. This includes improvements in contrast and reflectivity, ultimately providing users with a superior viewing experience.
The present invention provides a cholesterol liquid crystal display and driving method thereof. The cholesterol liquid crystal display comprises a display panel and a liquid crystal driving unit.
The display panel is used to display images composed of a row of imaging drive pixels and multiple rows of non-imaging drive pixels. The liquid crystal driving unit concurrently activates the display panel to display the image by using a plurality of the first driving voltages applied to the non-imaging drive pixels and a plurality of the second driving voltages applied to the imaging drive pixels. The first driving voltage has a quantity of the first pulse waves in a unit time, while the second driving voltage has a quantity of the second pulse waves in the unit time, where the quantity of the first pulse waves exceeds the quantity of the second pulse waves.
The display panel features multiple common electrode scan lines (COM Line), which are electrically coupled to the liquid crystal driving unit for image display. The imaging driving pixels are triggered by at least one common electrode scan line with a second driving voltage, characterized by the quantity of the second pulse waves. Besides, the non-imaging driving pixels are activated by other common electrode scan lines with a first driving voltage, distinguished by the quantity of the first pulse waves. The common electrode scan lines with the first driving voltage may influence the overall reflectivity, making the image brighter or darker based on voltage or time parameters. However, this ultimately does not impact the imaging effect.
The quantity of the first pulse waves within a unit time is at least 5 times greater than the quantity of the second pulse waves, and the higher the multiple, the better the display effect.
Moreover, the second driving voltage is categorized as a Selection voltage, while the first driving voltage is designated as a Non-Selection voltage.
The first driving voltage also exhibits a wave peak and a wave valley, and these features persist for a period of time respectively.
The unit time is defined as either a positive half-wave period or a negative half-wave period. In other words, each of the positive half-wave period and the negative half-wave period can be used to represent the unit time, respectively.
In one embodiment, the quantity of the first pulse waves in the positive half-wave period of the unselected voltage may be equal to or not equal to the quantity of the first pulse waves in the negative half-wave period.
In one embodiment, the first pulse wave frequency within the unit time is determined by the quantity of the first pulse waves, and similarly, the second pulse wave frequency within the unit time is determined by the quantity of the second pulse waves. In the unselected state, part of the first pulse wave frequency in the positive or negative half-wave period may be either equal or unequal to the other part of the first pulse wave frequency.
In one embodiment, the quantity of the first pulse waves within the unit time determines the first pulse wave frequency, while the quantity of the second pulse waves within the unit time determines the second pulse wave frequency. Consequently, the non-equal voltage peak frequency is designated as the first pulse wave frequency of either the positive half-wave period or the negative half-wave period in the unselected state.
In another embodiment, the quantity of the first pulse waves represents a quantity of multiple first pulse waves within the unit time. The peak value of the first pulse waves during either the positive or negative half-wave period in the unselected state is a fixed voltage for a specific duration.
Furthermore, the present invention also discloses a driving method for a cholesteric liquid crystal display. The display panel is designed for displaying images, where the images are produced by one imaging driving pixel and several non-imaging driving pixels. The driving method encompasses the following steps:
Step: Apply a first driving voltage with a quantity of the first pulse waves to the non-imaging driving pixel within a unit time. Meanwhile, apply a second driving voltage with a quantity of the second pulse waves to the imaging driving pixel within the same unit time to drive the display panel. Note that the quantity of the first pulse waves exceeds the quantity of the second pulse waves.
Step: The display panel is used to display the images.
The display panel has a plurality of common electrode scan lines which are electrically connected to the liquid crystal driving unit for image display. An imaging driving pixel is activated by at least one common electrode scan line using a second driving voltage with the quantity of the second pulse waves. Besides, the non-imaging driving pixels are activated by other common electrode scan lines using a first driving voltage with the quantity of the first pulse waves.
Furthermore, within the unit time, the quantity of the first pulse waves is at least 5 times greater than the quantity of the second pulse waves, and the greater the multiple, the better the display effect.
The second driving voltage is assigned as a Selection voltage, and the first driving voltage is assigned as a Non-Selection voltage.
The first driving voltage also exhibits a wave peak and a wave valley, and the wave peak and the wave valley persist within their time intervals respectively.
The unit time is defined as either a positive or negative half-wave period.
In still another embodiment, the quantity of the first pulse waves in the positive half-wave period of the unselected voltage may be equal to or not equal to the quantity of the first pulse waves in the negative half-wave period.
In one embodiment, the quantity of the first pulse waves within the unit time represents a first pulse wave frequency, while the quantity of the second pulse waves within the unit time represents a second pulse wave frequency. In the unselected state, part of the first pulse wave frequency in the positive or negative half-wave period may be either equal or unequal to the other part of the first pulse wave frequency.
In one embodiment, the quantity of the first pulse waves within the unit time determines the first pulse wave frequency, while the quantity of the second pulse waves within the unit time determines the second pulse wave frequency. Consequently, the non-equal voltage peak frequency is designated as the first pulse wave frequency of either the positive half-wave period or the negative half-wave period in the unselected state.
In another embodiment, the quantity of the first pulse waves represents a quantity of multiple first pulse waves within the unit time. The peak value of the first pulse waves during either the positive or negative half-wave period in the unselected state is a fixed voltage for a specific duration.
Therefore, the present invention provides a cholesteric liquid crystal display and its driving method. By employing various high-frequency methods during the unselected state within different unit times, the display achieves enhancements such as increased contrast or improved reflectivity. Within the unit time, the quantity of first pulse waves is at least 5 times greater than the quantity of second pulse waves, with a higher multiple correlating to a better display effect.
The aforementioned illustrations are exemplary for the purpose of further explaining the scope of the present invention. Other objectives and advantages related to the present invention will be illustrated in the subsequent descriptions and appended drawings. [0001]
The foregoing features of the present invention may be combined with the following drawings in various combinations without exclusivity, unless expressly indicated otherwise. Apparently, descriptions of drawings in the following may be some of embodiments of the present invention, those of ordinary skill in the art may derive other drawings based on the following drawings without unduly experiments.
The aforementioned constructions and associated functions and following detailed descriptions are exemplary for the purpose of further explaining the scope of the present invention. Other objectives and advantages related to the present invention will be illustrated in the subsequent descriptions and appended drawings. Furthermore, the present invention may be embodied in various modifications, and descriptions and illustrations are not-limiting.
The purpose of the present invention is to enhance the display effect of a cholesteric liquid crystal display and its driving method, aiming to improve contrast, increase reflectivity, reduce black shadows, and enhance the user's viewing experience.
The present invention relates to a cholesteric liquid crystal display. Please refer to
The display panel 20 is used for displaying an image 22, which comprises an imaging driving pixel 24 and multiple non-imaging driving pixels 26. The imaging driving pixel 24 is further composed of multiple sub-imaging driving pixels 25, while a non-imaging driving pixel 26 consists of multiple sub-non-imaging driving pixels 27.
The liquid crystal driving unit 50 concurrently drives the display panel 20 to display the image 22 using multiple first driving voltages 51 for the non-imaging driving pixels 26 and a second driving voltage 52 for the imaging driving pixels 24. The second driving voltage 52 may serve as a selected voltage, while the first driving voltage 51 may act as an unselected voltage.
Comparing
Furthermore, the display panel 20 comprises multiple common electrode scan lines 23, electrically connected to the liquid crystal driving unit 50 for image display. The imaging driving pixels 24 are activated by at least one common electrode scan line 23 supplied by the second driving voltage 52 with the quantity of the second pulse waves, while the non-imaging driving pixels 26 are driven by other common electrode scan lines 23 supplied by the first driving voltages 51 with the quantity of the first pulse waves. The common electrode scan lines 23, supplied by the first driving voltage 51, may influence the overall reflectivity to be brighter or darker due to voltage or time parameters, but it does not significantly impact the imaging effect.
By taking the bright state curve in
As depicted in
Please refer to
Refer to
Refer to
Furthermore, the present invention also provides a driving method 2 for a cholesteric liquid crystal display. Please refer to
Step 1 (S01): Apply a first driving voltage 51 characterized by the quantity of the first pulse waves to the non-imaging driving pixel 26 within a unit time T. Simultaneously, apply a second driving voltage 52 characterized by the quantity of the second pulse waves to the imaging driving pixel 24. It is noteworthy that the quantity of the first pulse waves exceeds the quantity of the second pulse waves.
Step 2 S02: The display panel 20 is used to display the image 22.
As stated previously, the display panel 20 is equipped with multiple common electrode scan lines 23. These common electrode scan lines 23 are electrically connected to the liquid crystal driving unit 50 to facilitate the display of the image 22. Specifically, the imaging driving pixel 24 is activated through the utilization of at least one common electrode scan line 23 that employs the second driving voltage 52 characterized by the quantity of the second pulse waves. Besides, the non-imaging driving pixels 26 are activated through the utilization of other one common electrode scan lines 23 that employs the first driving voltage 51 characterized by the quantity of the first pulse waves.
Moreover, the quantity of first pulse waves within the unit time T is at least 5 times greater than the quantity of second pulse waves, and the higher the multiple, the more pronounced the display effect.
Please refer to
Therefore, the present invention introduces a cholesteric liquid crystal display and its driving method. It is evident that employing various high-frequency methods within different unit times T in the unselected state, such as fully applying the first driving voltage 51 in high frequency, partially in high frequency, or with discontinuous high frequency, serves to enhance contrast and improve reflectivity. It is important to note that, within the unit time T, the quantity of the first pulse waves is at least 5 times greater than the quantity of the second pulse waves. The higher this multiple, the more favorable the display effect, resulting in fewer black shadows being produced.
The descriptions illustrated above set forth simply the preferred embodiments of the present invention; however, the characteristics of the present invention are by no means restricted thereto. All changes, alterations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the present invention set forth by the following claims.
Number | Date | Country | Kind |
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113100654 | Jan 2024 | TW | national |