Cholesteric liquid crystal writing and picture output apparatus, and cholesteric liquid crystal writing and localized picture erasing apparatus

Abstract

Provided in the present invention are a cholesteric liquid crystal writing and picture output apparatus, and a cholesteric liquid crystal writing and localized picture erasing apparatus. The cholesteric liquid crystal writing and picture output apparatus comprises a cholesteric liquid crystal display module, a drive module, a control module, a storage module, a picture copying key and an output interface. The cholesteric liquid crystal display module is further provided, close to a light-emergent surface, with a plurality of TFT light sensing assemblies, TFT switch assemblies, scanning lines, data line groups, and light sensing areas arranged in an array. Each light sensing area has a scanning line and a data line group which are arranged in a staggered manner, each data line group includes a data drive line and a data collection line, and each light sensing area further has a TFT light sensing assembly and a TFT switch assembly. The drive module has a plurality of paired data pin groups, each data pin group includes one data drive pin and one data collection pin, and when the number of data pin groups is N, correspondingly, the number of data drive pins is N, the number of data collection pins is N and the total number of pins is 2N.

Description

Cholesterol liquid crystal writing and image output device and image partial erasing device Technical Field

[0001] The present invention relates to the field of liquid crystal display technology, and in particular to a liquid crystal writing device based on cholesteric liquid crystal technology and equipped with a light sensing component and a switch component, which has both picture output and partial picture erasing functions. Background Art

[0002] Because of their bistability, cholesteric liquid crystal displays offer advantages such as energy conservation, low power consumption, and excellent image retention. Amid the global ESG trend, cholesteric liquid crystal displays have become the preferred choice for large-format e-books and also offer considerable advantages in large-format electronic whiteboard applications. However, writing and annotating notes are essential features of e-books and electronic whiteboards. While cholesteric liquid crystal displays easily enable this, outputting, printing, and even partially erasing the screen after writing notes remains a challenge in existing technologies.

[0003] Please refer to FIG1 for prior art related to a cholesteric liquid crystal writing tablet, patent number TWI669648. In the figure, light sensing area 121 includes a switch component 1212 and a light sensing component 1211. A main control circuit 141 controls a mode switch 142 to switch between a voltage output mode M1 and a voltage write mode M2. When switched to voltage write mode M2, switch component 1212 displays a preset image on the cholesteric liquid crystal writing tablet. When switched to voltage output mode M1, light sensing component 1211 stores the image on the cholesteric liquid crystal writing tablet. However, because switch element 1212 and light sensor element 1211 are electrically connected in series, when a new image is initially displayed, the cholesteric liquid crystal is reset by a high voltage, entering a homotropic state. This allows almost all light to pass through. Light sensor element 1211 is affected by external light, generating maximum leakage current, which in turn results in the highest voltage drop. This voltage drop also changes with the increased light reflection from switch element 1212 driving the cholesteric liquid crystal, creating a dynamic voltage drop, varying from high to low. Therefore, the voltage signals transmitted by mode control lines Mm, Mm+1, Mm+2, etc. are not the original voltage signals intended to drive switch element 1212. This creates a mutual restraint between the two, resulting in color errors in the displayed image. Therefore, the color displayed on the cholesteric liquid crystal writing board by activation of switch element 1212 is not exactly the preset color, resulting in image distortion and a poor user experience. This technical challenge remains to be resolved.

[0004] Summary of the Invention

[0005] In order to solve the problems of the prior art, the first preferred embodiment of the present invention provides a cholesterol liquid crystal writing and image output device. Through the improved structure, a preset image can be presented on the cholesterol liquid crystal display module, writing can be done on the image, and the written image can be output for archiving or reuse.

[0006] The cholesteric liquid crystal writing and image output device includes a cholesteric liquid crystal display module, a driver module, a control module, a storage module, and an output interface. The cholesteric liquid crystal display module is used to display images and has a light incident surface and a light emitting surface opposite the light incident surface. The control module and the storage module are electrically coupled to the driver module, and the output interface is electrically coupled to the storage module.

[0007] On the light-emitting surface of the cholesteric liquid crystal display module, the cholesteric liquid crystal writing and image output device further includes a plurality of TFT light sensing elements capable of switching between an active mode and an inactive mode, a plurality of TFT switch elements capable of switching between an active mode and an inactive mode, a plurality of parallel scan lines, a plurality of parallel data line groups, and a plurality of light sensing regions arranged in an array. Each light sensing region has at least one scan line and at least one data line group arranged in an alternating pattern. Each data line group includes a data drive line and a data collection line. Each light sensing region also has a TFT light sensing element and a TFT switch element.

[0008] The data driving line is electrically coupled to the TFT switch element in the light sensing area, the data collecting line is electrically coupled to the TFT light sensing element in the light sensing area, and the TFT light sensing element and the TFT switch element are separately configured without a series or parallel relationship.

[0009] The driver module has multiple pins, including multiple paired data pin groups. Each data pin group includes a data drive pin and a data collection pin. Each data drive pin is electrically coupled to a data drive line and connected in series to a TFT switch element. Each data collection pin is electrically coupled to a data collection line and connected in series to a TFT light sensing element. The number of data pin groups is N, corresponding to the number of data drive pins is N, the number of data collection pins is N, and the total number of pins is N.

[0010] When the TFT switch component is in the active mode, the TFT light sensing component is in the inactive mode. The data drive pin sends a position signal and a color signal of the primary display screen to the TFT switch component. The cholesterol liquid crystal display module generates a corresponding primary display screen within the light sensing area through the TFT switch component.

[0011] When the TFT light sensor is in an active mode and the TFT switch is in a non-active mode, the TFT light sensor receives light within the light sensing area that passes through the light-emitting surface of the cholesteric liquid crystal display module, generating a corresponding internal resistance and output voltage. This is then transmitted back through the data collection pin to form position signals and color signals for the secondary display sub-screens in the light sensing area, which are stored in the storage module. All secondary display sub-screens form a secondary display screen. When there is no written track on the light-incident surface of the cholesteric liquid crystal display module, the secondary display screen is identical to the primary display screen. However, when there is a written track on the light-incident surface of the cholesteric liquid crystal display module, the secondary display screen is different from the primary display screen.

[0012] The storage module is used to store multiple secondary display images, wherein the first secondary display image is the same as the primary display image. The output interface outputs the secondary display images stored in the storage module, especially the secondary display images with writing tracks.

[0013] In order to solve the problems of the prior art, the second preferred embodiment of the present invention provides a cholesterol liquid crystal writing and partial screen erasing device. Through the improved structure, writing can be performed on the screen displayed by the cholesterol liquid crystal display module, the writing track can be partially erased, and the erased screen can be restored to the original screen while retaining the screen of the undelete area.

[0014] The cholesterol liquid crystal writing and partial screen erasing device includes a cholesterol liquid crystal writing and screen output device as described in the first preferred embodiment, an optical erasing plate, a partial erasing button, a partial restoring button, and a comparison module.

[0015] The local wipe button and the local restore button are electrically coupled to the control module; the optical wipe plate is provided with a visible light emitting device for emitting visible light with a wavelength greater than 600nm. When the local wipe button is triggered, the visible light emitting device of the optical wipe plate forms a wiping track when it moves on the light incident surface of the cholesterol liquid crystal display module.

[0016] When the local recovery button is triggered, the TFT light sensing component switches from a non-activated mode to an activated mode, thereby generating a secondary display image and storing it in the storage module.

[0017] The storage module stores multiple secondary display screens, including an original screen, a writing screen, and an erased screen. The original screen is the first secondary display screen stored when the TFT light sensor element is first switched to the active mode. The writing screen is the secondary display screen stored in the storage module after the screen copy button is activated. The erased screen is the secondary display screen stored in the storage module after the partial restore button is activated. The original screen, writing screen, and erased screen each further include multiple original sub-screens, multiple writing sub-screens, and multiple erased sub-screens corresponding to the multiple light sensor areas.

[0018] The comparison module is used to compare the differences between the wiping sub-frames and the writing sub-frames in all light sensing areas, thereby locating light sensing difference areas where there are differences between the two.

[0019] After confirming the existence of the light-sensing difference area, the TFT light-sensing component is switched to the inactive mode, and the TFT switch component is switched to the active mode. The data drive pin sends a position signal and a color signal of the original sub-image corresponding to the light-sensing difference area to the TFT switch component, so that the cholesterol liquid crystal display module generates the corresponding original sub-image within the light-sensing difference area through the TFT switch component, thereby completing the partial erasure and restoration of the display image.

[0020] In summary, the cholesterol liquid crystal writing and screen output device, and the cholesterol liquid crystal writing and screen partial erasing device provided by the present invention, through independent TFT light sensing components and TFT switch components that do not have a series or parallel separation configuration relationship, although using a larger total number of pins of the driving module, can transmit voltage signals faster than any existing technology, store display images, including writing images and erasing images, faster and without distortion, and at the same time perform partial erasing and restoration of the display image, thereby improving the user's interactive experience and convenience of use.

[0021] Other features and beneficial effects of the present invention will be described in the subsequent description. The objectives and other beneficial effects of the present invention can be achieved and obtained through the structures specifically pointed out in the description, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work. The positional relationships described in the drawings in the following description are based on the directions of the components drawn in the diagrams, unless otherwise specified.

[0023] FIG1 is a schematic diagram of the prior art;

[0024] FIG2 is a functional diagram of a cholesteric liquid crystal writing and image output device according to a first preferred embodiment of the present invention;

[0025] FIG3 is a circuit connection diagram of a cholesteric liquid crystal writing and image output device according to a first preferred embodiment of the present invention;

[0026] FIG4 is a structural diagram of a cholesteric liquid crystal display module 10 in a first preferred embodiment of the present invention;

[0027] FIG5 is a functional relationship diagram of a cholesterol liquid crystal writing and partial screen erasing device according to a second preferred embodiment of the present invention.

[0028] Figure numerals: 1: Cholesteric liquid crystal writing and screen output device 2: Cholesteric liquid crystal writing and screen partial erasing device 10: Cholesteric liquid crystal display module 101: First partial light-transmitting layer 102: Second partial light-transmitting layer 103: Third partial light-transmitting layer 111: First cholesteric liquid crystal layer 112: Second cholesteric liquid crystal layer 113: Third cholesteric liquid crystal layer 12: Liquid crystal control area 21: TFT light sensing component 22: Fixed reference voltage 23: TFT switch component 24: Scan line 25: Data line group 26: Data drive line 27: Data collection line 28: Light sensing area 288: Light sensing difference area 30: Drive module 31: Data pin group 32: Data drive pin 33: Data collection pin 40: Control module 44: Comparison module 50: Storage module 53: Screen copy button 55: Output interface 70: Optical erasing plate 801: Partial erasing button 802: Partial recovery button 341: Position signal 351: Chroma signal DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments; the technical features designed in the different implementations of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variations thereof all mean "at least including".

[0031] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integrally formed connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0032] First preferred embodiment: Cholesteric liquid crystal writing and image output device

[0033] The first preferred embodiment proposed by the present invention is a cholesterol liquid crystal writing and picture output device 1, which can solve the problems of the prior art through the improved structure. Please refer to Figures 2 and 3. Figure 2 is a functional association diagram of the cholesterol liquid crystal writing and picture output device 1 proposed by the present invention, and Figure 3 is a circuit connection diagram of the cholesterol liquid crystal writing and picture output device 1.

[0034] The cholesteric liquid crystal writing and image output device 1 includes a cholesteric liquid crystal display module 10 , a driving module 30 , a control module 40 , a storage module 50 , and an output interface 55 .

[0035] The cholesteric liquid crystal display module 10 is used to display images for viewing by a user and has a light incident surface and a light emitting surface opposite the light incident surface. The control module 40 and the storage module 50 are electrically coupled to the driving module 30, and the output interface 55 is electrically coupled to the storage module 50. The cholesteric liquid crystal display module 10 further includes a plurality of liquid crystal control areas 12 arranged in an array.

[0036] Near the light-emitting surface of the cholesteric liquid crystal display module 10, the cholesteric liquid crystal writing and image output device 1 is further provided with a plurality of TFT light sensors 21, a plurality of TFT switch elements 23, a plurality of parallel scan lines 24, a plurality of parallel data line groups 25, and a plurality of light sensing regions 28 arranged in an array. The TFT light sensors 21 and the TFT switch elements 23 each have two modes: an active mode and a deactivated mode, and can be switched between these modes based on commands from the control module 40.

[0037] The cholesteric liquid crystal display module 10 further includes a plurality of liquid crystal control areas 12 arranged in an array, and each light sensing area 28 corresponds to at least one liquid crystal control area 12 . Two different light sensing areas 28 cannot correspond to the same liquid crystal control area 12 .

[0038] Each photosensitive region 28 has a plurality of scan lines 24 and a plurality of data line groups 25 arranged in an interlaced pattern. Each data line group 25 includes a data drive line 26 and a data collection line 27. Each photosensitive region 28 has a TFT photosensitive element 21 and a TFT switch element 23. The TFT photosensitive element 21 is used to receive light emitted from the light-emitting surface of the cholesteric liquid crystal display module 10 within the photosensitive region. The data drive line 26 is electrically coupled to the TFT switch element 23 in the photosensitive region 28, and the data collection line 27 is electrically coupled to the TFT photosensitive element 21 in the photosensitive region 28. As shown in FIG. 3 , the TFT photosensitive element 21 and the TFT switch element 23 are independently connected to the driver module 30 and are not connected in series or parallel, so the signals do not interfere with each other. Compared to the prior art shown in Figure 1 , in which switch element 1212 and light sensor element 1211 are connected in series, they mutually constrain each other. Consequently, the voltage signals transmitted by mode control lines Mm, Mm+1, Mm+2, etc. are not the original voltage signals intended to drive switch element 1212, nor are they the sensing signals transmitted by light sensor element 1211, causing image distortion. The present invention's TFT light sensor element 21 and TFT switch element 23 are independently connected to driver module 40, without being connected in series or parallel. Therefore, the signals do not interfere with each other, effectively resolving the problems of the prior art.

[0039] Referring again to FIG. 3 , the TFT light sensor element 21 has a fixed reference voltage 22 , which ranges from approximately 2 volts to 10 volts. When the TFT light sensor element 21 is actuated, its internal resistance varies due to differences in the amount of light received, causing the voltage drop across the TFT light sensor element 21 to vary. This, in turn, causes a change in the voltage signal received by the data collection pin 33 of the data collection line 27 , thereby generating a position signal 341 and a color signal 351 for the light sensing region 28 .

[0040] The driving module 30 has multiple pins, including multiple paired data pin groups 31, each data pin group 31 includes a data driving pin 32 and a data collection pin 33, each data driving pin 32 is electrically coupled to each data driving line 26 and connected in series to the TFT switch component 23, each data collection pin 33 is electrically coupled to the data collection line 27 and connected in series to the TFT light sensing component 21, and when the number of data pin groups 31 is N, the corresponding number of data driving pins 32 is N, and the number of data collection pins 33 is N, then the total number of pins is 2N, that is, when the number of data pin groups 31 is four, the corresponding number of data driving pins 32 is four, and the number of data collection pins 33 is also four, then the total number of pins is eight.

[0041] The data driving pins 32 and the data collecting pins 33 are arranged in an interlaced manner in the driving module 30. For example, one data driving pin 32 is connected to one data collecting pin 33, another data driving pin 32, and another data collecting pin 33. This can avoid voltage surges.

[0042] The TFT light sensing element 21 and the TFT switch element 23 operate in a time-sharing manner and will not operate simultaneously.

[0043] When a user wishes to display a preset image, such as a courseware image, on the cholesteric LC display module 10, the TFT switch assembly 23 switches to an active mode, while the TFT light sensor assembly 21 switches to a deactivated mode. Data driver pin 32 transmits a primary display image position signal 341 and a color signal 351 to the TFT switch assembly 23. The cholesteric LC display module 10 generates the corresponding primary display image within the light sensor region 28 via the TFT switch assembly 23. Once the image is displayed, the TFT switch assembly 23 switches to a deactivated mode. Due to the bistable nature of the cholesteric LC, the cholesteric LC display module 10 continues to display the aforementioned primary display image.

[0044] When a user wishes to copy the image displayed by the CLC display module 10, the TFT light sensor 21 switches to active mode. The TFT light sensor 21 receives light from the light-sensing region 28 that passes through the light-emitting surface of the CLC display module 10, generating a corresponding internal resistance and output voltage. This signal is then transmitted back through the data collection pin 33 to form a position signal 341 and a color signal 351 for the secondary display sub-image in the light-sensing region 28. These signals are then stored in the storage module 50. All the secondary display sub-images constitute a single secondary display image. Once the secondary display image is stored, the TFT light sensor 21 switches to inactive mode. The purpose of the TFT light sensor 21 is to copy and store the image displayed by the CLC display module 10. This function is particularly important for writing tablets. Because CLC is pressure-sensitive, when subjected to external pressure, the CLC transforms at the pressure point, forming a writing track. This is what is commonly seen in CLC writing tablets. However, this type of cholesteric liquid crystal writing tablet basically does not have the function of copying and storing the writing track or writing image. The present invention solves this problem through the TFT light sensing component 21 and the storage module 50.

[0045] The storage module 50 is used to store multiple secondary display images. The first secondary display image is the same as the primary display image. If there is no writing track on the cholesterol liquid crystal display module 10 when the TFT light sensing component 21 is activated, the stored secondary display image is also the same as the primary display image.

[0046] The output interface 55 is used to output the secondary display screen stored in the storage module 50 to the outside. Specifically, it can be a USB interface, or a Bluetooth or WIFI interface to output the secondary display screen as a file; the output interface 55 can also be a printing device to directly print out the secondary display screen on paper. The present invention is not limited to this.

[0047] Furthermore, the cholesteric liquid crystal writing and image output device 1 includes a screen copy button 53 electrically coupled to the control module 40 for issuing a screen copy command to switch the TFT light sensor element 21 to an active mode, thereby generating a secondary display image and storing it in the storage module 50. In other words, the screen copy button 53 issues a command to store the display image on the cholesteric liquid crystal display module 10 in the storage module 50. The present invention is not limited to this, as long as it can issue a screen copy command.

[0048] In a preferred embodiment, referring to FIG. 4 , the cholesteric liquid crystal display module 10 of the present invention further comprises a first partially light-transmitting layer 101, a first cholesteric liquid crystal layer 111, a second partially light-transmitting layer 102, a second cholesteric liquid crystal layer 112, a third partially light-transmitting layer 103, and a third cholesteric liquid crystal layer 113, arranged from the light incident surface to the light exit surface. This improves the color rendering and color saturation of the image.

[0049] The first cholesteric liquid crystal layer 111 is used to reflect incident light in a first frequency band, which is 600-680 MHz and mainly a blue light band.

[0050] The second cholesteric liquid crystal layer 112 is used to reflect incident light in a second frequency band, which is 480-600 MHz and mainly a green light band.

[0051] The third cholesteric liquid crystal layer 113 is used for reflecting incident light in a third frequency band, which is 405-480 MHz and mainly a red light band.

[0052] The first partially transparent layer 101 is disposed between the light incident surface and the first cholesteric liquid crystal layer 111. It is configured to absorb incident light with a frequency higher than a first predetermined frequency, which is 780 to 800 MHz and primarily represents UV light. Specifically, the first partially transparent layer 101 is configured to minimize the amount of UV light entering the first cholesteric liquid crystal layer 111.

[0053] The second partially transparent layer 102 is disposed between the first cholesteric liquid crystal layer 111 and the second cholesteric liquid crystal layer 112. It is configured to absorb incident light having a frequency higher than a second predetermined frequency, which is 600 to 620 MHz and primarily represents the blue wavelength band. Specifically, the second partially transparent layer 102 is configured to absorb as much blue light as possible that is not reflected by the first cholesteric liquid crystal layer 111, thereby preventing this blue light from entering the second cholesteric liquid crystal layer 112.

[0054] The third partially transparent layer 103 is disposed between the second cholesteric liquid crystal layer 112 and the third cholesteric liquid crystal layer 113. It is designed to absorb incident light above a third predetermined frequency, which is 480 to 530 MHz and primarily represents green light. Specifically, the third partially transparent layer 103 is designed to absorb as much green light as possible that is not reflected by the second cholesteric liquid crystal layer 112, preventing this green light from entering the third cholesteric liquid crystal layer 113 and allowing only the remaining red light to enter the third cholesteric liquid crystal layer 113.

[0055] With the above structure, the cholesteric liquid crystal display module 10 of the cholesteric liquid crystal writing and image output device 1 can provide better image color rendering and color saturation.

[0056] Second preferred embodiment: Cholesteric liquid crystal writing and screen partial erasing device

[0057] Based on the cholesteric liquid crystal writing and image output device 1 proposed in the first preferred embodiment, the present invention further proposes a second preferred embodiment, a cholesteric liquid crystal writing and partial image erasing device 2. Please refer to Figure 5 in conjunction with Figures 2 and 3, which is a functional diagram of the second embodiment. The cholesteric liquid crystal writing and partial image erasing device 2 includes the cholesteric liquid crystal writing and image output device 1, an optical eraser 70, a partial erase button 801, a partial restore button 802, and a comparison module 44.

[0058] The technical solution of the cholesteric liquid crystal writing and image output device 1 is as described in the first preferred embodiment above and will not be repeated here.

[0059] The local erase button 801 and the local restore button 802 are both electrically coupled to the control module 40 .

[0060] The optical wiping plate 70 is provided with a visible light emitting device for emitting visible light with a wavelength greater than 600nm. When the partial wiping button 801 is triggered, the visible light emitting device of the optical wiping plate 70 moves on the light incident surface of the cholesterol liquid crystal display module, forming a wiping track.

[0061] When the local recovery button 802 is triggered, the TFT light sensor element 21 switches to the active mode and generates a secondary display image and stores it in the storage module 50 . The secondary display image at this time is a display image including the wiping track.

[0062] As described in the first preferred embodiment, when the TFT light sensor element 21 is activated, its internal resistance changes accordingly due to differences in the amount of light received, causing a change in the voltage drop across the TFT light sensor element 21. This embodiment also utilizes the same principle to form a wiping track with an optical wiper 70. The optical wiper 70 is equipped with a visible light emitting device for emitting a large amount of light flux, causing a significant change in the internal resistance and voltage drop across the TFT light sensor element 21. As shown in FIG4 , the cholesteric liquid crystal display module 10 of the present invention further includes a first partially transparent layer 101, a second partially transparent layer 102, and a third partially transparent layer 103, arranged from the light incident surface to the light exit surface. The first partially transparent layer 101 absorbs UV light, the second partially transparent layer 102 absorbs blue light, and the third partially transparent layer 103 absorbs green light. In other words, if the optical wiper 70 emits UV, blue, or green light, a large portion of it will be absorbed by the first partially transparent layer 101, the second partially transparent layer 102, and the third partially transparent layer 103. Only visible light, primarily red, can be easily sensed by the TFT light sensor 21 and form a wiping track. Therefore, the visible light emitting device of the optical wiper should primarily emit visible light with a wavelength greater than 600 nm; preferably, the visible light wavelength range is between 620 and 760 nm.

[0063] The multiple secondary display screens of storage module 50 include an original screen, a writing screen, and an erased screen. The original screen is the first secondary display screen stored when the TFT light sensor component 21 is first switched to the active mode. The writing screen is the secondary display screen stored after the screen copy button is activated. The erased screen is the secondary display screen stored after the partial restore button 802 is activated. The original screen, writing screen, and erased screen respectively include multiple original sub-screens, multiple writing sub-screens, and multiple erased sub-screens corresponding to the multiple light sensor areas 28.

[0064] To clear the wiped trace and restore the original image, the simplest approach is to refresh the entire image. This involves switching all TFT switch elements 23 to active mode and all TFT light sensing elements 21 to inactive mode. Data driver pin 32 transmits primary display position signal 341 and chrominance signal 351 to all TFT switch elements 23. The cholesteric liquid crystal display module 10 then generates a corresponding, complete original display image within the light sensing area 28 via the TFT switch elements 23. However, this approach has significant drawbacks:

[0065] First, the response speed of cholesteric liquid crystal is slow. If the entire screen is refreshed, the user experience of a large-sized cholesteric liquid crystal display module 10 is extremely poor.

[0066] 2. The display screen of the cholesteric liquid crystal display module 10 may contain other important writing tracks that do not need to be erased. If the entire screen is refreshed, those important writing tracks that do not need to be erased will be cleared.

[0067] To address the aforementioned issues, the present invention further utilizes a comparison module 44 to compare the differences between the wiped sub-images and the written sub-images in all optical sensing areas 28. For optical sensing areas without wiped traces, the wiped sub-images and the written sub-images are identical. For optical sensing areas with wiped traces, the wiped sub-images and the written sub-images are different, and this is defined as an optical sensing difference area 288.

[0068] After confirming the presence of the light sensing difference area 288, the TFT light sensing element 21 switches to a deactivated mode, while the TFT switch element 23 switches to an activated mode. The data drive pin 32 transmits a position signal 341 and a color signal 351 corresponding to the original sub-image of the light sensing difference area 288 to the TFT switch element 23 corresponding to the light sensing difference area 288. This causes the cholesteric liquid crystal display module 10 to generate the corresponding original sub-image within the light sensing difference area 288 through the TFT switch element 23, thereby completing the partial erasure and restoration of the display screen. More specifically, the present invention only performs screen refresh and reset for the light sensing difference area 288. For portions outside of the light sensing difference area 288, the screen remains unchanged, and no screen refresh or reset is performed. Since the erasing track usually only occupies a small part of the entire screen, the light sensing difference area 288 also only occupies a small part of all light sensing areas 28. Only the light sensing difference area 288 is refreshed and reset, the refresh speed is faster, and the existence of other writing tracks in the screen can be maintained, and the user experience and feeling can be significantly improved.

[0069] In a preferred embodiment, the partial erase button 801 and the partial restore button 802 can be provided on the optical eraser plate 70 to facilitate the user's wiping operation. Of course, the partial erase button 801 and the partial restore button 802 can also be provided on the cholesteric liquid crystal display module 10, or even as virtual buttons on the display screen, and the present invention is not limited thereto.

[0070] In summary, the cholesterol liquid crystal writing and screen output device 1 and the cholesterol liquid crystal writing and screen partial erasing device 2 provided by the present invention use independent TFT light sensing components 21 and TFT switch components 23 that are not in a series or parallel separation configuration relationship. Although a larger total number of pins of the driving module is used, voltage signals can be transmitted faster than any existing technology, and display images, including writing images and erasing images, can be stored faster and without distortion. At the same time, the display image can be partially erased and restored, thereby improving the user's interactive experience and convenience of use.

[0071] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention may be improved in only one or several aspects, without having to simultaneously solve all the technical problems listed in the prior art or background art. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as limiting the claim.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cholesteric liquid crystal writing and image output device (1), comprising a cholesteric liquid crystal display module (10), a driving module (30), a control module (40), a storage module (50), and an output interface (55), wherein the cholesteric liquid crystal display module (10) has a light incident surface and a light emitting surface opposite to the light incident surface; characterized in that: The control module (40) and the storage module (50) are electrically coupled to the driving module (30), and the output interface (55) is electrically coupled to the storage module (50); Close to the light-emitting surface of the cholesteric liquid crystal display module (10), the cholesteric liquid crystal writing and image output device (1) further comprises a plurality of TFT light sensing components (21) capable of switching between an active mode and an inactive mode, a plurality of TFT switch components (23) capable of switching between an active mode and an inactive mode, a plurality of parallel scan lines (24), a plurality of parallel data line groups (25), and a plurality of light sensing regions (28) arranged in an array, each of the light sensing regions (28) having at least one scan line (24) and at least one data line group (25) arranged in an alternating manner, each of the data line groups (25) comprising a data driving line (26) and a data collecting line (27), and each of the light sensing regions (28) also having one of the TFT light sensing components (21) and one of the TFT switch components (23); The data driving line (26) is electrically coupled to the TFT switch element (23) in the light sensing area (28), the data collecting line (27) is electrically coupled to the TFT light sensing element (21) in the light sensing area (28), and the TFT light sensing element (21) and the TFT switch element (23) are in a separate configuration without a series or parallel relationship; The driving module (30) has a plurality of pins, including a plurality of paired data pin groups (31), each of the data pin groups (31) including a data driving pin (32) and a data collecting pin (33), each of the data driving pins (32) being electrically coupled to each of the data driving lines (26) and connected in series to the TFT switch component (23), each of the data collecting pins (33) being electrically coupled to the data collecting line (27) and connected in series to the TFT light sensing component (21), wherein the number of the data pin groups (31) is N, and the corresponding data driving pins (32) are connected in series to the TFT light sensing component (21). The number of the active pins (32) is N, the number of the data collection pins (33) is N, and the total number of the pins is 2N; when the TFT switch component (23) is in an active mode, the TFT light sensing component (21) is in a non-active mode, the data driving pin (32) sends a position signal (341) and a color signal (351) of a primary display screen to the TFT switch component (23), and the cholesterol liquid crystal display module (10) generates the corresponding primary display screen within the light sensing area (28) through the TFT switch component (23); When the TFT light sensing component (21) is in the actuation mode, the TFT switch component (23) is in the non-actuation mode. The TFT light sensing component (21) receives light within the light sensing area (28) that penetrates through the light emitting surface of the cholesterol liquid crystal display module (10), generates corresponding internal resistance and output voltage, and transmits the signals back through the data collection pin (33), thereby forming the position signal (341) and the color signal (351) of the secondary display sub-image of the light sensing area (28), which are stored in the storage module (50). All the secondary display sub-images constitute one secondary display image. The storage module (50) is used to store a plurality of the secondary display images, wherein the first secondary display image is the same as the primary display image; The output interface (55) outputs the secondary display screen stored in the storage module (50) to the outside.

2. The cholesteric liquid crystal writing and image output device (1) according to claim 1, characterized in that: The data driving pins (32) and the data collecting pins (33) are arranged in an alternating manner in the driving module (30).

3. [Corrected 17.04.2024 according to Rule 26] The cholesteric liquid crystal writing and image output device (1) according to claim 2, characterized in that: The TFT light sensing component (21) has a fixed reference voltage (22), and the fixed reference voltage (22) = 2-10V.

4. The cholesteric liquid crystal writing and image output device (1) according to claim 3, characterized in that: The cholesteric liquid crystal display module (10) further comprises a plurality of liquid crystal control areas (12) arranged in an array, and each of the light sensing areas (28) corresponds to at least one of the liquid crystal control areas (12).

5. The cholesteric liquid crystal writing and image output device (1) according to claim 4, characterized in that: The light incident surface of the cholesterol liquid crystal display module (10) is compressed to form a writing track, and the secondary display screen is a screen formed by the writing track covering the primary display screen.

6. The cholesteric liquid crystal writing and image output device (1) according to claim 5, characterized in that: It further comprises a screen copy button (53) electrically coupled to the control module (40); when the screen copy button (53) is triggered, the TFT light sensing component (21) switches to an action mode, generates the secondary display screen and stores it in the storage module (50).

7. The cholesteric liquid crystal writing and image output device (1) according to claim 6, characterized in that: The cholesteric liquid crystal display module (10) further comprises a first local light-transmitting layer (101), a first cholesteric liquid crystal layer (111), a second local light-transmitting layer (102), a second cholesteric liquid crystal layer (112), a third local light-transmitting layer (103), and a third cholesteric liquid crystal layer (113) arranged from the light incident surface to the light exit surface; The first cholesterol liquid crystal layer (111) is used to reflect incident light in a first frequency band, and the first frequency band is 600-680 MHz; The second cholesterol liquid crystal layer (112) is used for reflecting incident light in a second frequency band, and the second frequency band is 480-600 MHz; The third cholesterol liquid crystal layer (113) is used for reflecting incident light in a third frequency band, and the third frequency band is 405-480 MHz; The first local light-transmitting layer (101) is used to absorb incident light with a frequency higher than a first set frequency, and the first set frequency is 780 to 800 MHz; The second partially transparent layer (102) is used to absorb incident light with a frequency higher than a second set frequency, and the second set frequency is 600-620 MHz; The third partially light-transmitting layer (103) is used to absorb incident light with a frequency higher than a third set frequency, and the third set frequency is 480 to 530 MHz.

8. A cholesterol liquid crystal writing and partial screen erasing device (2), comprising a cholesterol liquid crystal writing and screen output device (1) as claimed in claim 7, an optical erasing plate (70), a partial erasing button (801), a partial recovery button (802), and a comparison module (44); characterized in that: The local wipe button (801) and the local restore button (802) are electrically coupled to the control module (40); The optical wiping plate is provided with a visible light emitting device for emitting visible light with a wavelength greater than 600 nm, and when the local wiping button (801) is triggered, the visible light emitting device of the optical wiping plate moves on the light incident surface of the cholesterol liquid crystal display module to form a wiping track; When the local restore button (802) is triggered, the TFT light sensing component (21) switches to the action mode, and the secondary display screen is generated and stored in the storage module (50); the multiple secondary display screens of the storage module (50) include an original screen, a writing screen, and an wiping screen, the original screen is the first secondary display screen stored when the TFT light sensing component (21) switches to the action mode for the first time, the writing screen is the secondary display screen stored after the screen copy button is activated, and the wiping screen is the secondary display screen stored after the local restore button is activated, and the original screen, the writing screen, and the wiping screen respectively further include multiple original sub-screens, multiple writing sub-screens, and multiple wiping sub-screens corresponding to multiple light sensing areas (28); The comparison module (44) is used to compare the differences between the wiping sub-images and the writing sub-images of all the light sensing areas (28), thereby locating a light sensing difference area (288) where the two have differences; After confirming the existence of the light sensing difference area (288), the TFT light sensing component (21) is switched to the inactive mode, the TFT switch component (23) is switched to the active mode, and the data driving pin (32) sends the position signal (341) and the chromaticity signal (351) of the original sub-image corresponding to the light sensing difference area (288) to the TFT switch component (23), so that the cholesterol liquid crystal display module (10) generates the corresponding original sub-image within the light sensing difference area (288) through the TFT switch component (23), thereby completing the partial wiping and restoration of the display image.

9. The cholesterol liquid crystal writing and partial screen erasing device (2) according to claim 8, characterized in that: The wavelength of visible light emitted by the visible light emitting device is in the range of 620-760 nm.

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