Light-sensitive touch reflective display device and touch detection method

Abstract

The invention discloses a light-sensitive touch reflective display device and a touch detection method. The light-sensitive touch reflective display device comprises a cholesterol liquid crystal box, wherein the cholesterol liquid crystal box comprises an array substrate, an opposite substrate and a cholesterol liquid crystal layer; a plurality of scanning lines, a plurality of data lines, a plurality of first thin film transistors, a plurality of signal output lines, a plurality of photosensitive thin film transistors, a plurality of signal input electrodes and a plurality of pixel electrodes distributed in an array are arranged on the array substrate, and the pixel electrodes are electrically connected with the scanning lines and the data lines close to the first thin film transistors through the first thin film transistors. The photosensitive thin film transistors are located in the opening areas of the pixel units and electrically connected with the signal input electrodes and the signal output lines. According to the reflective display device, the photosensitive thin film transistor is arranged on the array substrate, so that the photosensitive thin film transistor and the first thin film transistor for controlling the pixel driving signal can be manufactured together, the box thickness of the reflective display device cannot be increased, and the manufacturing cost of the reflective display device can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of displays, and particularly to a light-sensitive touch reflective display device and a touch detection method. Background Art

[0002] Display panels have the advantages of being thin, light, durable, and energy-saving and environmentally friendly with low power consumption. However, they need to be used with a backlight, resulting in a thick module and high cost. Electronic paper displays (reflective displays) have become a type of display that meets the needs of the public. Electronic paper displays can use external light sources to display images, unlike liquid crystal displays that require a backlight. Therefore, in an outdoor environment with strong sunlight, the information on the electronic paper can still be clearly seen without the problem of viewing angles. Moreover, due to their advantages such as power saving, high reflectivity, and contrast ratio, electronic paper displays are now widely used in e-readers (such as e-books, e-newspapers) or other electronic components (such as price tags).

[0003] Existing electronic paper displays usually adopt E-Ink microcapsule technology (microcapsule electronic ink technology), SiPix microcup technology (microcup electrophoretic display technology), Bridgestone electronic liquid powder technology, cholesteric liquid crystal display (CLCD) technology, microelectromechanical system (MEMS) technology, or electrowetting technology. However, the existing electronic paper display technology is not as mature as liquid crystal display technology, with low mass production efficiency and relatively high manufacturing costs. Moreover, existing electronic paper displays cannot achieve color display.

[0004] In the prior art, for a reflective display device using cholesteric liquid crystals, due to the requirements of the cholesteric liquid crystal pitch, cholesteric liquid crystals with one pitch can reflect one color and transmit light of other colors. Therefore, a single-layer cholesteric liquid crystal reflective display device can display black characters on a yellow background or yellow characters on a black background, red characters on a black background or black characters on a red background, etc., thus achieving color display. However, existing cholesteric liquid crystal display devices usually adopt an on-cell touch method, which not only increases the cell thickness of the display device but also increases the manufacturing cost of the display device. Summary of the Invention

[0005] In order to overcome the disadvantages and deficiencies in the prior art, the purpose of the present invention is to provide a light-sensitive touch reflective display device and a touch detection method to solve the problems of relatively thick cell thickness and relatively high manufacturing cost of the touch-type cholesteric liquid crystal display device in the prior art.

[0006] The purpose of the present invention is achieved by the following technical solutions: The present invention provides a light-sensitive touch reflective display device, including a cholesteric liquid crystal cell. The cholesteric liquid crystal cell includes an array substrate, a counter substrate disposed opposite to the array substrate, and a cholesteric liquid crystal layer located between the counter substrate and the array substrate. The counter substrate is disposed on one side of the cholesteric liquid crystal cell close to the external environment, and the array substrate is disposed on one side of the cholesteric liquid crystal cell far from the external environment; A plurality of scan lines, a plurality of data lines, a plurality of first thin film transistors, a plurality of signal output lines, a plurality of photosensitive thin film transistors, a plurality of signal input electrodes, and a plurality of pixel electrodes arranged in an array are provided on the array substrate. The plurality of scan lines and the plurality of data lines are insulated and cross each other to define a plurality of pixel units. The pixel electrodes are electrically connected to the adjacent scan lines and data lines through the first thin film transistors. The photosensitive thin film transistors are located in the opening areas of the pixel units and are electrically connected to the signal input electrodes and the signal output lines; A black matrix and a first common electrode cooperating with the pixel electrodes are provided on the counter substrate. The black matrix is provided with openings corresponding to the opening areas.

[0007] Further, the scan lines are multiplexed as the signal input electrodes, and the photosensitive thin film transistors are electrically connected to the scan lines and the signal output lines.

[0008] Further, both the gate and the source of the photosensitive thin film transistor are electrically connected to the scan lines, and the drain of the photosensitive thin film transistor is electrically connected to the signal output lines.

[0009] Further, a second thin film transistor is provided on the array substrate. The drain of the photosensitive thin film transistor is electrically connected to the adjacent scan lines and the signal output lines through the second thin film transistor.

[0010] Further, a second common electrode is provided on the array substrate. The second common electrode is multiplexed as the signal input electrode, and the photosensitive thin film transistors are electrically connected to the second common electrode and the signal output lines.

[0011] Further, the gate of the photosensitive thin film transistor is electrically connected to the scan lines, the source of the photosensitive thin film transistor is electrically connected to the second common electrode, and the drain of the photosensitive thin film transistor is electrically connected to the signal output lines.

[0012] Further, a second thin film transistor is provided on the array substrate. The drain of the photosensitive thin film transistor is electrically connected to the adjacent scan lines and the signal output lines through the second thin film transistor.

[0013] Further, a second thin film transistor is provided on the array substrate, and the drain of the photosensitive thin film transistor is electrically connected to the scanning line and the signal output line adjacent to the second thin film transistor through the second thin film transistor; The gate and the source of the photosensitive thin film transistor are both electrically connected to the second common electrode.

[0014] Further, a signal amplifier is provided on the array substrate. The signal amplifier has an input end, an output end, a common end, and an input end of a filter capacitor. The input end is connected to the signal output line, the output end is used for connecting to a touch control chip, the common end is used for grounding, and two ends of the filter capacitor are respectively connected to the input end and the output end; And / or, the reflective display device includes a light absorbing layer provided as a whole surface, and the light absorbing layer is provided on the side of the reflective display device that is farthest from the external environment.

[0015] The present application also provides a touch detection method for the reflective display device as described above. The touch detection method includes: Obtaining a change amount of the output voltage of the photosensitive thin film transistor, and comparing the change amount of the output voltage with a threshold voltage; When the change amount of the output voltage is less than or equal to the threshold voltage, it is determined as a non-touch state; when the change amount of the output voltage is greater than the threshold voltage, it is determined as a touch state.

[0016] The beneficial effects of the present invention are as follows: By providing a photosensitive thin film transistor on the array substrate and arranging the photosensitive thin film transistor in the opening area of the pixel unit, the photosensitive thin film transistor can be manufactured together with the first thin film transistor that controls the pixel driving signal, which not only does not increase the cell thickness of the reflective display device, but also reduces the manufacturing cost of the reflective display device; By detecting the strength of the light sensing signal through the photosensitive thin film transistor, the position where the user touches can be judged, and touch operation is realized. Description of the Drawings

[0017] Figure 1 is a schematic structural diagram of the reflective display device in Embodiment 1 of the present invention.

[0018] Figure 2 is a schematic plan view of the array substrate in Embodiment 1 of the present invention.

[0019] Figure 3 is a schematic plan view of a single pixel of the array substrate in Embodiment 1 of the present invention.

[0020] Figure 4 is a schematic structural diagram of the signal amplifier in Embodiment 1 of the present invention.

[0021] Figure 5 It is a schematic plan view of the opposed substrate in the first embodiment of the present invention.

[0022] Figure 6 It is a schematic diagram of the principle of the transformation of three states of cholesteric liquid crystal in the first embodiment of the present invention.

[0023] Figure 7 It is a schematic diagram of the driving signal for the transformation of three states of cholesteric liquid crystal in the first embodiment of the present invention.

[0024] Figure 8 It is a schematic structural diagram of the reflective display device in the first embodiment of the present invention when displaying a pure red picture.

[0025] Figure 9 It is one of the schematic structural diagrams of the reflective display device in the first embodiment of the present invention when displaying a pure black picture.

[0026] Figure 10 It is another schematic structural diagram of the reflective display device in the first embodiment of the present invention when displaying a pure black picture.

[0027] Figure 11 It is one of the schematic structural diagrams of the reflective display device in the first embodiment of the present invention when displaying a red and black picture.

[0028] Figure 12 It is another schematic structural diagram of the reflective display device in the first embodiment of the present invention when displaying a red and black picture.

[0029] Figure 13 It is a schematic structural diagram of a user touching the reflective display device in the first embodiment of the present invention.

[0030] Figure 14 It is a curve graph of the output signal corresponding to the photosensitive thin-film transistor of the reflective display device under different ambient light illuminations in the first embodiment of the present invention.

[0031] Figure 15 It is a schematic plan view of the array substrate in the second embodiment of the present invention.

[0032] Figure 16 It is a schematic plan view of a single pixel of the array substrate in the second embodiment of the present invention.

[0033] Figure 17 It is a schematic plan view of the array substrate in the third embodiment of the present invention.

[0034] Figure 18 It is a schematic plan view of a single pixel of the array substrate in the third embodiment of the present invention.

[0035] Figure 19 It is a schematic plan view of the opposed substrate in the third embodiment of the present invention.

[0036] Figure 20 It is a schematic plan view of the array substrate in the fourth embodiment of the present invention.

[0037] Figure 21 It is a schematic plan view of a single pixel of the array substrate in the fourth embodiment of the present invention.

[0038] Figure 22 It is a schematic structural view of the reflective display device in the fifth embodiment of the present invention when displaying a pure white screen.

[0039] Figure 23 It is a schematic structural view of the reflective display device in the fifth embodiment of the present invention when displaying a pure cyan screen.

[0040] Figure 24 It is a schematic structural view of the reflective display device in the fifth embodiment of the present invention when displaying a pure red screen.

[0041] Figure 25 It is a schematic structural view of the reflective display device in the fifth embodiment of the present invention when displaying a color screen. Detailed implementation manners

[0042] To further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features, and effects of the reflective display device and touch detection method based on the present invention as follows: [Embodiment 1] Figure 1 It is a schematic structural view of the reflective display device in the first embodiment of the present invention. Figure 2 It is a schematic plan view of the array substrate in the first embodiment of the present invention. Figure 3 It is a schematic plan view of a single pixel of the array substrate in the first embodiment of the present invention. Figure 4 It is a schematic structural view of the signal amplifier in the first embodiment of the present invention. Figure 5 It is a schematic plan view of the counter substrate in the first embodiment of the present invention.

[0043] Such as Figures 1 to 5As shown in the figure, a reflective display device with optical touch control provided in the first embodiment of the present invention includes a cholesteric liquid crystal cell 10 and an absorbent layer 20 provided on the entire surface. The absorbent layer 20 is provided on the side of the reflective display device farthest from the external environment, that is, the cholesteric liquid crystal cell 10 is provided on the side of the absorbent layer 20 close to the external environment, and ambient light enters the reflective display device from one side of the cholesteric liquid crystal cell 10. Among them, the absorbent layer 20 is used to absorb the light passing through the cholesteric liquid crystal cell 10, so that the reflective display device is darker in the black state, thereby improving the contrast. Optionally, the absorbent layer 20 is made of black ink, and the L value (representing light and darkness) of the black ink is greater than 25 and the OD value (optical density) is greater than 4, so that the absorbent layer 20 has the characteristics of high blackness and good gloss, ensuring that the black screen is darker. Of course, the absorbent layer 20 can be made of BM material. In this embodiment, the number of cholesteric liquid crystal cells 10 is one, so that a single color picture can be displayed. Of course, the number of cholesteric liquid crystal cells 10 can also be set to multiple, so as to achieve color displays of more colors.

[0044] The cholesteric liquid crystal cell 10 includes an array substrate 12, a counter substrate 11 disposed opposite to the array substrate 12, and a cholesteric liquid crystal layer 13 located between the counter substrate 11 and the array substrate 12. The counter substrate 11 is provided on the side of the cholesteric liquid crystal cell 10 close to the external environment, and the array substrate 12 is provided on the side of the cholesteric liquid crystal cell 10 away from the external environment. Ambient light enters the cholesteric liquid crystal cell 10 from one side of the counter substrate 11. Among them, the cholesteric liquid crystal molecules in the cholesteric liquid crystal layer 13 all reflect the same color of light in the reflective state. For example, they can reflect red light, green light, cyan light, blue light, etc. In this embodiment, the case where the cholesteric liquid crystal molecules in the cholesteric liquid crystal layer 13 reflect red light in the reflective state is taken as an example for description.

[0045] Among them, the cholesteric liquid crystal molecules have three stable textures: P state (Planar, planar texture state, reflective state), FC state (Focal Conic, focal cone state, fog state), and H state (transparent state). In the P state, the reflection spectrum of the cholesteric liquid crystal is in the visible light spectrum range, and the cholesteric liquid crystal reflects bright colored light, and the specific color it reflects can be set according to the pitch of the cholesteric liquid crystal; in the FC state, the cholesteric liquid crystal no longer reflects the above-mentioned colored light, and the light can be scattered and transmitted through the cholesteric liquid crystal; in the H state, the cholesteric liquid crystal no longer reflects the above-mentioned colored light, and the light can be directly transmitted through the cholesteric liquid crystal and has no scattering effect on the light. Under the action of a certain electric field, these three states can be converted into each other.

[0046] As Figures 1 to 3As shown, multiple scan lines 101, multiple data lines 102, multiple first thin film transistors 103, multiple signal output lines 104, multiple photosensitive thin film transistors 105, multiple signal input electrodes, and multiple pixel electrodes 121 arranged in an array are provided on the array substrate 12. The multiple scan lines 101 and the multiple data lines 102 are insulated and cross each other to define multiple pixel units P. Each pixel unit P is provided with a first thin film transistor 103, a photosensitive thin film transistor 105, and a pixel electrode 121. Among them, the pixel electrode 121 is electrically connected to the scan line 101 and the data line 102 adjacent to the first thin film transistor 103 through the first thin film transistor 103; the photosensitive thin film transistor 105 is located in the opening area Po of the pixel unit P and is electrically connected to the signal input electrode and the signal output line 104. Both the first thin film transistor 103 and the photosensitive thin film transistor 105 have a gate, a source, a drain, and an active layer. The gate of the first thin film transistor 103, the gate of the photosensitive thin film transistor 105, and the scan line 101 are located on the same layer and are etched from the same metal layer. The active layers of the first thin film transistor 103 and the photosensitive thin film transistor 105 are located on the same layer and are etched from the same semiconductor layer. The source / drain (source and drain) of the first thin film transistor 103, the source / drain (source and drain) of the photosensitive thin film transistor 105, and the data line 102 are located on the same layer and are etched from the same metal layer, that is, the first thin film transistor 103 and the photosensitive thin film transistor 105 are fabricated simultaneously using the same process. In this embodiment, the signal output line 104 and the data line 102 are parallel to each other and arranged alternately. The signal output line 104 and the data line 102 are located on the same layer and are etched from the same metal layer; of course, the signal output line 104 can also be parallel to the scan line 101 and arranged alternately, and the signal output line 104 and the scan line 101 are located on the same layer and are etched from the same metal layer.

[0047] As Figure 1 and Figure 4 shown, a black matrix 112 and a first common electrode 111 cooperating with the pixel electrode 121 are provided on the counter substrate 11. The black matrix 112 is provided with an opening 112a corresponding to the opening area Po, that is, the projection of the black matrix 112 on the array substrate 12 covers the scan line 101, the data line 102, the first thin film transistor 103, the signal output line 104, and the signal input electrode. Among them, the first common electrode 111 is a planar electrode that entirely covers the counter substrate 11.

[0048] Figure 6 is a schematic diagram of the principle of the three-state transformation of cholesterol liquid crystal in the first embodiment of the present invention. Figure 7 is a schematic diagram of the driving signal for the three-state transformation of cholesterol liquid crystal in the first embodiment of the present invention. Combining Figure 1 、 Figure 6 and Figure 7As shown, a common voltage signal Vcom is applied to the first common electrode 111, and a first electrical signal V1 is continuously applied to the pixel electrode 121. There is a voltage difference (about 20V) between the common voltage signal Vcom and the first electrical signal V1. A strong vertical electric field will be formed between the common electrode and the pixel electrode, and the cholesteric liquid crystal molecules will rotate and stagnate in the H state (transparent state). A common voltage signal Vcom is applied to the first common electrode 111, and a second electrical signal V2 is applied to the pixel electrode 121. There is a voltage difference (for example, 20V) between the second electrical signal V2 and the common voltage signal Vcom, and the second electrical signal V2 gradually becomes the same as the common voltage signal Vcom within the first preset time, that is, the second electrical signal V2 first has a large voltage difference from the common voltage signal Vcom and then slowly decreases and becomes the same as the common voltage signal Vcom. Therefore, a strong vertical electric field will be formed between the common electrode and the pixel electrode first, and then the vertical electric field slowly disappears, causing the cholesteric liquid crystal molecules to rotate and stagnate in the FC state, which is a scattering state and has a light-scattering effect. A common voltage signal Vcom is applied to the first common electrode 111, and a third electrical signal V3 is applied to the pixel electrode 121. There is a voltage difference (for example, 30V) between the third electrical signal V3 and the common voltage signal Vcom, and the third electrical signal V3 directly becomes the same as the common voltage signal Vcom at the second preset time, and the second preset time is less than the first preset time, that is, the third electrical signal V3 first has a large voltage difference from the common voltage signal Vcom and then quickly decreases and becomes the same as the common voltage signal Vcom. Therefore, a strong vertical electric field will be formed between the common electrode and the pixel electrode first, and then the vertical electric field quickly disappears, causing the cholesteric liquid crystal molecules to rotate and stagnate in the P state, which is a reflective state. Among them, the arrangement directions of the cholesteric liquid crystal molecules are different, and the reflected visible light spectra are different, and the remaining spectra are transmitted. The P state and the FC state do not require voltage to maintain. The reflection spectral band (Δλ) of the cholesteric liquid crystal molecules is proportional to the pitch (Po) of the cholesteric liquid crystal molecules and the average refractive index (n = (ne + no) / 2), and its formula is: Δλ = nPo. Therefore, cholesteric liquid crystal molecules with different pitches can reflect light of different colors in the reflective state.

[0049] As Figures 1 to 3As shown, in this embodiment, a second common electrode 122 is provided on the array substrate 12. The second common electrode 122 is multiplexed as a signal input electrode, that is, the second common electrode 122 is used as a signal input electrode. The photosensitive thin-film transistor 105 is electrically connected to the second common electrode 122 and the signal output line 104. Among them, since the cholesteric liquid crystal layer 13 requires a voltage to maintain the transparent state (H state), the second common electrode 122 can also be used to apply a common signal and form a storage capacitor with the pixel electrode 121, so that the voltage difference between the pixel electrode 121 and the first common electrode 111 can be maintained. Of course, in other embodiments, an electrode line can also be separately provided to be used as a signal input electrode.

[0050] Furthermore, both the gate and the source of the photosensitive thin-film transistor 105 are electrically connected to the second common electrode 122, that is, the photosensitive thin-film transistor 105 is controlled by the second common electrode 122. By applying a common electrode signal to the second common electrode 122, the photosensitive thin-film transistor 105 can be turned on; when the photosensitive thin-film transistor 105 is under the irradiation of external light and is turned on, the photosensitive thin-film transistor 105 generates a photocurrent (i.e., an electrical signal carrying light intensity information) according to the light intensity.

[0051] A second thin-film transistor 106 is provided on the array substrate 12. The drain of the photosensitive thin-film transistor 105 is electrically connected to the scan line 101 and the signal output line 104 adjacent to the second thin-film transistor 106 through the second thin-film transistor 106. Since all the second common electrodes 122 are simultaneously applied with a common electrode signal, the scanning line 101 and the second thin-film transistor 106 are used to control the turn-on timing of each row of photosensitive thin-film transistors 105, so that the position of the photosensitive thin-film transistor 105 in the user touch area can be identified. Among them, the second thin-film transistor 106 also has a gate, a source, a drain, and an active layer. The gate of the first thin-film transistor 103, the gate of the second thin-film transistor 106, the gate of the photosensitive thin-film transistor 105, and the scan line 101 are located on the same layer and are etched from the same metal layer. The active layer of the first thin-film transistor 103, the active layer of the second thin-film transistor 106, and the active layer of the photosensitive thin-film transistor 105 are located on the same layer and are etched from the same semiconductor layer. The source / drain (source and drain) of the first thin-film transistor 103, the source / drain (source and drain) of the second thin-film transistor 106, the source / drain (source and drain) of the photosensitive thin-film transistor 105, and the data line 102 are located on the same layer and are etched from the same metal layer, that is, the first thin-film transistor 103, the second thin-film transistor 106, and the photosensitive thin-film transistor 105 are fabricated simultaneously using the same process. Among them, the projection of the black matrix 112 on the array substrate 12 also covers the second thin-film transistor 106 to prevent light from affecting the performance of the second thin-film transistor 106.

[0052] Further, as Figure 4 shown, a signal amplifier 107 is provided on the array substrate 12. The signal amplifier 107 is used to amplify the signal output by the signal output line 104, so as to facilitate the processing by the touch control chip. The signal amplifier 107 has an input end 107a, an output end 107b, a common end 107c, and an input end 107a of a filter capacitor 107d. The input end 107a is connected to the signal output line 104. The output end 107b is used to connect to the touch control chip. The common end 107c is used to be grounded. Two ends of the filter capacitor 107d are respectively connected to the input end 107a and the output end 107b.

[0053] Figure 8 FIG. is a schematic structural diagram of the reflective display device in Embodiment 1 of the present invention when displaying a pure red screen. As Figure 8 shown, when the reflective display device displays a pure red screen, all the cholesteric liquid crystal molecules in the cholesteric liquid crystal layer 13 are controlled to be in a reflective state and reflect red light, so that the entire reflective display device presents a red screen.

[0054] Figure 9 FIG. is one of the schematic structural diagrams of the reflective display device in Embodiment 1 of the present invention when displaying a pure black screen. Figure 10 FIG. is the second of the schematic structural diagrams of the reflective display device in Embodiment 1 of the present invention when displaying a pure black screen. As Figure 9 and Figure 10 shown, when the reflective display device displays a pure black screen, all the cholesteric liquid crystal molecules in the cholesteric liquid crystal layer 13 are controlled to be in a fog state ( Figure 9 ) or a transparent state ( Figure 10 ), and the light passes through the cholesteric liquid crystal layer 13 and is absorbed by the light absorption layer 20, so that the entire reflective display device presents a black screen.

[0055] Figure 11 FIG. is one of the schematic structural diagrams of the reflective display device in Embodiment 1 of the present invention when displaying a red and black screen. Figure 12 FIG. is the second of the schematic structural diagrams of the reflective display device in Embodiment 1 of the present invention when displaying a red and black screen. As Figure 9 and Figure 10 shown, when the reflective display device displays a red and black screen, the cholesteric liquid crystal molecules in the red area are controlled to be in a reflective state to reflect red light; the cholesteric liquid crystal molecules in the black area are controlled to be in a fog state ( Figure 11 ) or a transparent state ( Figure 12 ), and the light in the black area passes through the cholesteric liquid crystal layer 13 and is absorbed by the light absorption layer 20, so that the reflective display device presents a red and black screen.

[0056] The present application also provides a touch detection method for the reflective display device as described above. The touch detection method includes: Obtain the change amount of the output voltage of the photosensitive thin-film transistor 105, and compare the change amount of the output voltage with the threshold voltage.

[0057] When the change amount of the output voltage is less than or equal to the threshold voltage, it is determined as the non-touch state; when the change amount of the output voltage is greater than the threshold voltage, it is determined as the touch state.

[0058] Specifically, a touch signal is input to the corresponding photosensitive thin-film transistor 105 through the signal input electrode. The photosensitive thin-film transistor 105 outputs a voltage to the signal output line 104 according to the illumination brightness. The electrical signal transmitted by the signal output line 104 is received by the signal amplifier 107 and amplified, so as to facilitate subsequent signal operation and processing. After obtaining and storing the electrical signal amplified by the amplifier, the touch chip subtracts the electrical signal from the electrical signal at the previous moment (for example, the output voltage of the photosensitive thin-film transistor 105 in two consecutive frames) to obtain the change amount of the electrical signal at the current moment relative to the electrical signal at the previous moment: 1) Since the electrical signal is related to the light intensity irradiated on the photosensitive thin-film transistor 105, if the change amount of the electrical signal is greater than the threshold voltage Vth of the change amount of the electrical signal, it means that compared with front the previous moment, the light intensity sensed by the photosensitive thin-film transistor 105 has changed greatly, indicating that the light irradiated on the photosensitive thin-film transistor 105 has been blocked during this period, and a touch action has occurred. Immediately afterwards, the touch chip determines the pixel position where the large signal occurs as the touch position according to the large signal; 2) If the change amount of the electrical signal is less than or equal to the threshold voltage Vth of the change amount of the electrical signal, it means that the light intensity has not changed greatly during the period from the previous moment to the current moment, that is, the light irradiated on the photosensitive thin-film transistor 105 has not been blocked, and no touch action has occurred.

[0059]

[0060] Table 1 is a comparison table of the brightness level / LUX and the threshold voltage Vth / V of the touch chip corresponding to the optical touch to determine whether there is a touch. Figure 13 It is a schematic structural diagram when the user touches the reflective display device in the first embodiment of the present invention. Figure 14 It is a curve diagram of the output signal corresponding to the photosensitive thin-film transistor of the reflective display device under different ambient illuminances in the first embodiment of the present invention. As Figure 13 、 Figure 14As shown in Table 1 above, the illumination intensity of the photosensitive thin film transistor 105 when irradiated by ambient light is A0, and the illumination intensity of the photosensitive thin film transistor 105 when blocked by a finger is A1. There is a difference in the illumination intensity of the photosensitive thin film transistor 105 when irradiated by ambient light and when blocked by a finger. The leakage current of the photosensitive thin film transistor 105 when irradiated by ambient light and when blocked by a finger corresponds to the first current value I1 and the second current value I2, respectively. Since the cholesterol liquid crystal box is a reflective display, it needs the help of ambient light or an additional light source set outside to display. Therefore, when the cholesterol liquid crystal box is not touched, the leakage current of the photosensitive thin film transistor 105 when receiving the light intensity is larger than the leakage current of the photosensitive thin film transistor 105 when receiving the light intensity when it is touched, that is, when the cholesterol liquid crystal box is not touched, the leakage current Ids of the photosensitive thin film transistor 105 is also relatively large, and the first current value is I1 at this time; when it is touched, the second current value is I2, and the first current value I1 is greater than the second current value I2. The difference in charge caused by the difference in leakage current of the photosensitive thin film transistor 105 is converted into an output voltage through an integrator, and then the change in the output voltage can be judged to understand whether there is touch or no touch. The greater the light intensity, the greater the leakage current, and the lower the output voltage value; when the change in the output voltage on the signal output line 104 ΔV=V out (the voltage output at the current moment)-V (the voltage output at the previous moment) ≤ the threshold voltage Vth, it is a no-touch state; when the change in the output voltage on the signal output line 104 ΔV=V out-V>threshold voltage Vth, it is a touch state. As shown in Table 1, the brightness level / LUX of the ambient light is sensed by the light sensor of the reflective display device itself, and the value of the threshold voltage Vth for judging whether to touch the touch chip corresponding to the light-sensitive touch can be adaptively adjusted according to the brightness level / LUX (illuminance, which refers to the light intensity, indicating the luminous flux of visible light received per unit area) of the ambient light, so that the position touched by the user's finger on the reflective display device can be more accurately judged.

[0061] Among them, within one frame, the display driving process and the light-sensitive touch driving process are carried out simultaneously, and the signal output line 104 is used to read the electrical signal carrying light intensity information generated by the photosensitive thin film transistor 105, and the data line 102 is used to apply the data voltage signal to the first thin film transistor 103 to drive the cholesterol liquid crystal display. The two are carried out simultaneously and do not interfere with each other.

[0062] [Example 2] Figure 15 It is a schematic diagram of the planar structure of the array substrate in the second embodiment of the present invention. Figure 16 Schematic diagram of the planar structure of a single pixel of the array substrate in the second embodiment of the present invention. Figure 15 and Figure 16As shown, the reflective display device with optical touch control and the touch detection method provided in the second embodiment of the present invention are basically the same as those in the first embodiment ( Figures 1 to 14 ), except that: In this embodiment, the gate of the photosensitive thin-film transistor 105 is electrically connected to the scan line 101, the source of the photosensitive thin-film transistor 105 is electrically connected to the second common electrode 122, and the drain of the photosensitive thin-film transistor 105 is electrically connected to the signal output line 104. That is, in this embodiment, the gate and the source of the photosensitive thin-film transistor 105 are respectively connected to different signals. The photosensitive thin-film transistor 105 is controlled by the scan line 101. By applying a scan signal to the scan line 101, the photosensitive thin-film transistor 105 can be turned on. When the photosensitive thin-film transistor 105 is under the irradiation of external light and is turned on, the photosensitive thin-film transistor 105 generates a photocurrent (i.e., an electrical signal carrying light intensity information) according to the light intensity, and is connected to the touch chip through the signal output line 104 to determine whether there is a touch.

[0063] Those skilled in the art should understand that the rest of the structure and working principle of this embodiment are the same as those of the first embodiment, and will not be described in detail here.

[0064] [Embodiment Three] Figure 17 It is a schematic plan view of the array substrate in the third embodiment of the present invention. Figure 18 It is a schematic plan view of a single pixel of the array substrate in the third embodiment of the present invention. Figure 19 It is a schematic plan view of the counter substrate in the third embodiment of the present invention. As Figures 17 to 19 shown, the reflective display device with optical touch control and the touch detection method provided in the third embodiment of the present invention are basically the same as those in the first embodiment ( Figures 1 to 14 ), except that: In this embodiment, the scan line 101 is multiplexed as a signal input electrode, that is, the scan line 101 is used as the signal input electrode, and the photosensitive thin film transistor 105 is electrically connected to the scan line 101 and the signal output line 104. Optionally, both the gate and the source of the photosensitive thin film transistor 105 are electrically connected to the scan line 101, and the drain of the photosensitive thin film transistor 105 is electrically connected to the signal output line 104. That is, the photosensitive thin film transistor 105 is controlled by the scan line 101. By applying a scan signal to the scan line 101, the photosensitive thin film transistor 105 can be turned on. When the photosensitive thin film transistor 105 is irradiated by external light and is turned on, the photosensitive thin film transistor 105 generates a photocurrent (i.e., an electrical signal carrying light intensity information) according to the light intensity, and is connected to the touch control chip through the signal output line 104 to determine whether there is a touch. Since the scan line 101 is multiplexed as the signal input electrode and the photosensitive thin film transistor 105 is controlled by the scan line 101, in this embodiment, the second common electrode 122 can be not provided, thereby reducing the manufacturing cost. However, it is difficult to maintain the cholesteric liquid crystal layer 13 in the transparent state (H state), so that when the pixel unit P displays black, the corresponding cholesteric liquid crystal molecules need to be in the fog state (FC state).

[0065] In this embodiment, referring to Figure 2 , Figure 5 , Figure 17 , Figure 18 and Figure 19 , since the photosensitive thin film transistor 105 is controlled by the scan line 101, therefore, the second thin film transistor 106 can be not provided to control the turn-on timing of each row of photosensitive thin film transistors 105, thereby improving the aperture ratio of the pixel unit P. Of course, in other embodiments, it is not excluded that the second thin film transistor 106 can also be provided on the array substrate 12, and the drain of the photosensitive thin film transistor 105 is electrically connected to the scan line 101 and the signal output line 104 adjacent to the second thin film transistor 106 through the second thin film transistor 106.

[0066] Those skilled in the art should understand that the remaining structures and working principles of this embodiment are the same as those of Embodiment 1, and will not be elaborated here.

[0067] [Embodiment 4] Figure 20 is a schematic plan view of the array substrate in Embodiment 4 of the present invention. Figure 21 is a schematic plan view of a single pixel of the array substrate in Embodiment 4 of the present invention. As Figure 20 and Figure 21 shown, the light-sensitive touch reflection display device and the touch detection method provided in Embodiment 4 of the present invention are basically the same as those of the light-sensitive touch reflection display device and the touch detection method in Embodiment 1 ( Figures 1 to 14 ), the difference being that: In this embodiment, the gate of the photosensitive thin-film transistor 105 is electrically connected to the scanning line 101, the source of the photosensitive thin-film transistor 105 is electrically connected to the second common electrode 122, and the drain of the photosensitive thin-film transistor 105 is electrically connected to the signal output line 104. That is, in this embodiment, the gate and the source of the photosensitive thin-film transistor 105 are respectively connected to different signals. The photosensitive thin-film transistor 105 is controlled by the scanning line 101. By applying a scanning signal to the scanning line 101, the photosensitive thin-film transistor 105 can be turned on. When the photosensitive thin-film transistor 105 is irradiated by external light and turned on, the photosensitive thin-film transistor 105 generates a photocurrent (i.e., an electrical signal carrying light intensity information) according to the light intensity, and is connected to the touch control chip through the signal output line 104 to determine whether there is a touch.

[0068] In this embodiment, since the photosensitive thin-film transistor 105 is controlled by the scanning line 101, it is not necessary to provide the second thin-film transistor 106 to control the turn-on timing of each row of photosensitive thin-film transistors 105, thereby improving the aperture ratio of the pixel unit P.

[0069] Those skilled in the art should understand that the remaining structures and working principles of this embodiment are the same as those of the first embodiment, and will not be described in detail here.

[0070] [Embodiment Five] Figure 22 It is a schematic structural diagram of the reflective display device in Embodiment Five of the present invention when displaying a pure white screen. Figure 23 It is a schematic structural diagram of the reflective display device in Embodiment Five of the present invention when displaying a pure cyan screen. Figure 24 It is a schematic structural diagram of the reflective display device in Embodiment Five of the present invention when displaying a pure red screen. Figure 25 It is a schematic structural diagram of the reflective display device in Embodiment Five of the present invention when displaying a color screen. As Figures 22 to 25 shown, the light-sensitive touch reflective display device and the touch detection method provided in Embodiment Five of the present invention are basically the same as those of the first embodiment ( Figures 1 to 14 ), the second embodiment ( Figure 15 and Figure 16 ), the third embodiment ( Figures 17 to 19 ), and the fourth embodiment ( Figure 20 and Figure 21 ). The differences are as follows: In this embodiment, the number of the cholesteric liquid crystal cells 10 is two, and the two cholesteric liquid crystal cells 10 are stacked on each other. The two cholesteric liquid crystal cells 10 reflect different colors respectively in the reflective state, so as to achieve color display of more colors. Preferably, the two cholesteric liquid crystal cells 10 reflect complementary colors respectively in the reflective state, so that a white picture can be displayed. In this embodiment, it is described by taking the two cholesteric liquid crystal cells 10 reflecting red and cyan respectively in the reflective state as an example.

[0071] As Figure 22 shown, when the reflective display device displays a pure white picture, all the cholesteric liquid crystal molecules in the cholesteric liquid crystal layers 13 in the two cholesteric liquid crystal cells 10 are controlled to be in the reflective state and reflect red light and cyan light respectively. After the red light and the cyan light are mixed with each other, white light is obtained, so that the whole reflective display device presents a white picture.

[0072] As Figure 23 shown, when the reflective display device displays a pure cyan picture, all the cholesteric liquid crystal molecules in the cyan cholesteric liquid crystal layer 13 are controlled to be in the reflective state and reflect cyan light, while all the cholesteric liquid crystal molecules in the red cholesteric liquid crystal layer 13 are controlled to be in the fog state or the transparent state, so that the whole reflective display device presents a cyan picture.

[0073] As Figure 24 shown, when the reflective display device displays a pure red picture, all the cholesteric liquid crystal molecules in the red cholesteric liquid crystal layer 13 are controlled to be in the reflective state and reflect red light, while all the cholesteric liquid crystal molecules in the cyan cholesteric liquid crystal layer 13 are controlled to be in the fog state or the transparent state, so that the whole reflective display device presents a red picture.

[0074] As Figure 25 shown, when the reflective display device displays a color picture, all the corresponding cholesteric liquid crystal molecules in the two cholesteric liquid crystal layers 13 in the white area are controlled to be in the reflective state and reflect red light and cyan light respectively; all the corresponding cholesteric liquid crystal molecules in the cyan cholesteric liquid crystal layer 13 in the cyan area are controlled to be in the reflective state and reflect cyan light, while all the corresponding cholesteric liquid crystal molecules in the red cholesteric liquid crystal layer 13 in the cyan area are controlled to be in the fog state or the transparent state; all the corresponding cholesteric liquid crystal molecules in the red cholesteric liquid crystal layer 13 in the red area are controlled to be in the reflective state and reflect red light, while all the corresponding cholesteric liquid crystal molecules in the cyan cholesteric liquid crystal layer 13 in the red area are controlled to be in the fog state or the transparent state; all the corresponding cholesteric liquid crystal molecules in the two cholesteric liquid crystal layers 13 in the black area are controlled to be in the fog state or the transparent state, so that the reflective display device presents a display picture of four colors: cyan, red, black and white.

[0075] Those skilled in the art should understand that the remaining structures and working principles of this embodiment are the same as those of Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 4, and will not be elaborated here.

[0076] In this article, the orientation terms such as up, down, left, right, front, and back are defined based on the positions of the structures in the drawings and the positions relative to each other, only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the orientation terms should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second" used in this article are only for distinction in name and do not limit the quantity and order.

[0077] The above are only preferred embodiments of the present invention and do not impose any formal limitations on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications within the scope of the technical solution of the present invention by using the disclosed technical content above, which are equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A reflective display device with light-sensitive touch, characterized in that: The invention comprises a cholesteric liquid crystal box (10), wherein the cholesteric liquid crystal box (10) comprises an array substrate (12), an opposing substrate (11) arranged opposite to the array substrate (12), and a cholesteric liquid crystal layer (13) located between the opposing substrate (11) and the array substrate (12), wherein the opposing substrate (11) is arranged on a side of the cholesteric liquid crystal box (10) close to an external environment, and the array substrate (12) is arranged on a side of the cholesteric liquid crystal box (10) away from the external environment; The array substrate (12) is provided with a plurality of scanning lines (101), a plurality of data lines (102), a plurality of first thin film transistors (103), a plurality of signal output lines (104), a plurality of photosensitive thin film transistors (105), a plurality of signal input electrodes and a plurality of pixel electrodes (121) distributed in an array; the plurality of scanning lines (101) and the plurality of data lines (102) are mutually insulated and cross-defined to form a plurality of pixel units (P); the pixel electrode (121) is electrically connected to the scanning line (101) and the data line (102) adjacent to the first thin film transistor (103) through the first thin film transistor (103); the photosensitive thin film transistor (105) is located in an opening area (Po) of the pixel unit (P) and is electrically connected to the signal input electrode and the signal output line (104); The opposing substrate (11) is provided with a black matrix (112) and a first common electrode (111) matched with the pixel electrode (121); the black matrix (112) is provided with an opening (112a) corresponding to the opening area (Po).

2. The reflective display device with optical touch control according to claim 1, characterized in that: The scanning line (101) is multiplexed as the signal input electrode, and the photosensitive thin film transistor (105) is electrically connected to the scanning line (101) and the signal output line (104).

3. The reflective display device with optical touch control according to claim 2, characterized in that: The gate electrode and the source electrode of the photosensitive thin film transistor (105) are both electrically connected to the scanning line (101), and the drain electrode of the photosensitive thin film transistor (105) is electrically connected to the signal output line (104).

4. The reflective display device with optical touch control according to claim 3, characterized in that: A second thin film transistor (106) is provided on the array substrate (12), and the drain of the photosensitive thin film transistor (105) is electrically connected to the scanning line (101) and the signal output line (104) adjacent to the second thin film transistor (106) through the second thin film transistor (106).

5. The reflective display device with optical touch control according to claim 1, characterized in that: A second common electrode (122) is provided on the array substrate (12), the second common electrode (122) is reused as the signal input electrode, and the photosensitive thin film transistor (105) is electrically connected to the second common electrode (122) and the signal output line (104).

6. The reflective display device with optical touch control according to claim 5, characterized in that: The gate of the photosensitive thin film transistor (105) is electrically connected to the scanning line (101), the source of the photosensitive thin film transistor (105) is electrically connected to the second common electrode (122), and the drain of the photosensitive thin film transistor (105) is electrically connected to the signal output line (104).

7. The reflective display device with optical touch control according to claim 6, characterized in that: A second thin film transistor (106) is provided on the array substrate (12), and the drain of the photosensitive thin film transistor (105) is electrically connected to the scanning line (101) and the signal output line (104) adjacent to the second thin film transistor (106) through the second thin film transistor (106).

8. The reflective display device with optical touch control according to claim 5, characterized in that: A second thin film transistor (106) is provided on the array substrate (12), and the drain of the photosensitive thin film transistor (105) is electrically connected to the scan line (101) and the signal output line (104) adjacent to the second thin film transistor (106) through the second thin film transistor (106); The gate and source of the photosensitive thin film transistor (105) are both electrically connected to the second common electrode (122).

9. The reflective display device with optical touch control according to any one of claims 1 to 8, characterized in that: A signal amplifier (107) is provided on the array substrate (12), the signal amplifier (107) having an input end (107a), an output end (107b), a common end (107c), and an input end (107a) of a filter capacitor (107d), the input end (107a) being connected to a signal output line (104), the output end (107b) being used to connect to a touch chip, the common end (107c) being used to be grounded, and two ends of the filter capacitor (107d) being respectively connected to the input end (107a) and the output end (107b); And / or, the reflective display device comprises a light absorbing layer (20) disposed on the entire surface, and the light absorbing layer (20) is disposed on a side of the reflective display device that is farthest from the external environment.

10. A touch detection method, characterized in that: For the reflective display device according to any one of claims 1 to 9, the touch detection method comprises: Acquiring a change in output voltage of a photosensitive thin film transistor (105), and comparing the change in output voltage with a threshold voltage; When the change in the output voltage is less than or equal to the threshold voltage, it is determined to be a non-touch state; when the change in the output voltage is greater than the threshold voltage, it is determined to be a touch state.

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