Abstract:
An optical sensing circuit has a plurality of optical sensing units arranged so that the optical sensing circuit is ambient light insensitive or sensitive to light within certain spectrum. The sensitive spectra corresponding to the plurality of optical sensing units are different from one another.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application claims the benefit of priority to Taiwan Patent Application No. 105109004, filed Mar. 23, 2016. The entire content of the above identified application is incorporated herein by reference. 
         [0002]    Some references, which may include patents, patent applications and various publications, are cited and discussed in the description of this disclosure. The citation and/or discussion of such references is provided merely to clarify the description of the present disclosure and is not an admission that any such reference is “prior art” to the disclosure described herein. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference. 
       FIELD 
       [0003]    The present invention relates to relates to an optical sensing circuit and a display panel using the optical sensing circuit, and in particular, to an optical sensing circuit having a particular sensing frequency range and a display panel having the optical sensing circuit. 
       BACKGROUND 
       [0004]    An optical sensing circuit may be applied in an optical-touch apparatus, to implement optical-touch control (non-touch control). An existing optical sensing circuit can implement a feature of being sensitive to particular light (for example, red light). However, because red light is also a component of white light, when exposed to ambient light, an optical sensing circuit sensitive to red light sends a touch indication signal, causing an erroneous touch control event to occur. 
         [0005]    In view of this, it is an objective in the art to provide an organic light-emitting display device to reduce the border width of the organic light-emitting display device. 
       SUMMARY 
       [0006]    The present disclosure provides an optical sensing circuit and a display panel using the optical sensing circuit, to eliminate interference from ambient light or sense light of a particular color except three primary colors. 
         [0007]    According to an embodiment of the present disclosure, an optical sensing circuit having a first sensing component, a capacitor, a sampling circuit, a first ambient light sensing circuit, and a second ambient light sensing circuit is provided. The first sensing component has a first end and a second end, where a first current path between the first end of the first sensing component and the second end of the first sensing component is selectively established according to whether the first sensing component receives first colored light. The capacitor is separately electrically connected to the first end of the first sensing component and a first voltage end. The sampling circuit is electrically connected to the first end of the first sensing component. The first ambient light sensing circuit has a second sensing component and a third sensing component. The second sensing component has a first end and a second end, where the first end of the second sensing component is electrically connected to the second end of the first sensing component, and a second current path between the first end of the second sensing component and the second end of the second sensing component is selectively established according to whether the second sensing component receives the first colored light. The third sensing component has a first end and a second end, where the first end of the third sensing component is electrically connected to the second end of the first sensing component, the second end of the third sensing component is electrically connected to a voltage source, and a third current path between the first end of the third sensing component and the second end of the third sensing component is selectively established according to whether the third sensing component receives second colored light. The second ambient light sensing circuit is separately electrically connected to the second end of the second sensing component, a first signal end, and a voltage source, and is configured to electrically connect, in a sensing time interval, the first signal end to the second end of the second sensing component when the first colored light is sensed, and electrically connect the voltage source to the second end of the second sensing component when the second colored light is sensed. In the sensing time interval, a voltage of the first signal end is different from a voltage of the voltage source. 
         [0008]    According to an embodiment of the present disclosure, an optical sensing circuit having a first sensing component, a capacitor, a sampling circuit, a second sensing component, and a third sensing component is provided. The first sensing component has a first end and a second end, where a first current path between the first end of the first sensing component and the second end of the first sensing component is selectively established according to whether the first sensing component receives first colored light. The capacitor is separately electrically connected to the first end of the first sensing component and a first voltage end. The sampling circuit is electrically connected to the first end of the first sensing component. The second sensing component has a first end and a second end, where the first end of the second sensing component is electrically connected to the second end of the first sensing component, the second end of the second sensing component is electrically connected to a first signal end, and a second current path between the first end of the second sensing component and the second end of the second sensing component is selectively established according to whether the second sensing component receives second colored light. The third sensing component has a first end and a second end, where the first end of the third sensing component is electrically connected to the second end of the first sensing component, the second end of the third sensing component is electrically connected to a voltage source, and a third current path between the first end of the third sensing component and the second end of the third sensing component is selectively established according to whether the third sensing component receives third colored light. 
         [0009]    According to an embodiment of the present disclosure, an optical sensing circuit having a first color filtering component, a second color filtering component, a first photosensitive transistor switch, a capacitor, a sampling circuit, a second photosensitive transistor switch, a third photosensitive transistor switch, a fourth photosensitive transistor switch, and a fifth photosensitive transistor switch is provided. The first color filtering component blocks light except first colored light. The second color filtering component blocks light except second colored light. The first colored light and the second colored light are different from each other. The first photosensitive transistor switch is arranged opposite to the first color filtering component, and has a first end and a second end. The capacitor is separately electrically connected to the first end of the first photosensitive transistor switch and a first voltage end. The sampling circuit is electrically connected to the first end of the first photosensitive transistor switch. The second photosensitive transistor switch is arranged opposite to the first color filtering component, and has a control end, a first end, and a second end, where the first end of the second photosensitive transistor switch is electrically connected to the second end of the first photosensitive transistor switch, and the control end of the second photosensitive transistor switch is electrically connected to the second end of the second photosensitive transistor switch. The third photosensitive transistor switch is arranged opposite to the second color filtering component, and has a control end, a first end, and a second end, where both of the first end of the third photosensitive transistor switch and the control end of the third photosensitive transistor switch are electrically connected to the second end of the first photosensitive transistor switch, and the second end of the third photosensitive transistor switch is electrically connected to a voltage source. The fourth photosensitive transistor switch is arranged opposite to the first color filtering component, and has a control end, a first end, and a second end, where the first end of the fourth photosensitive transistor switch is electrically connected to the second end of the second photosensitive transistor switch, and both of the control end of the fourth photosensitive transistor switch and the second end of the fourth photosensitive transistor switch are electrically connected to a first signal end. The fifth photosensitive transistor switch is arranged opposite to the second color filtering component, and has a control end, a first end, and a second end, where both of the first end of the fifth photosensitive transistor switch and the control end of the fifth photosensitive transistor switch are electrically connected to the second end of the second photosensitive transistor switch, and the second end of the fifth photosensitive transistor switch is electrically connected to a voltage source. 
         [0010]    According to an embodiment of the present disclosure, an optical sensing circuit having a first color filtering component, a second color filtering component, a third color filtering component, a first photosensitive transistor switch, a capacitor, a sampling circuit, a second photosensitive transistor switch, and a third photosensitive transistor switch is provided. The first color filtering component blocks light except first colored light. The second color filtering component blocks light except second colored light. The third color filtering component blocks light except third colored light. The first colored light, the second colored light, and the third colored light are different from each other. The first photosensitive transistor switch is arranged opposite to the first color filtering component, and has a first end and a second end. The capacitor is separately electrically connected to the first end of the first photosensitive transistor switch and a first voltage end. The sampling circuit is electrically connected to the first end of the first photosensitive transistor switch. The second photosensitive transistor switch is arranged opposite to the second color filtering component, and has a control end, a first end, and a second end, where the first end of the second photosensitive transistor switch is electrically connected to the second end of the first photosensitive transistor switch, and both of the second end of the second photosensitive transistor switch and the control end of the second photosensitive transistor switch are electrically connected to a first signal end. The third photosensitive transistor switch has a control end, a first end, and a second end, where both of the first end of the third photosensitive transistor switch and the control end of the third photosensitive transistor switch are electrically connected to the second end of the first photosensitive transistor switch, and the second end of the third photosensitive transistor switch is electrically connected to a voltage source. 
         [0011]    According to an embodiment of the present disclosure, a display panel is provided. A substrate of the display panel has a plurality of pixel units, where each pixel unit includes at least three sub-pixels. One of the foregoing optical sensing circuits is configured in at least one of the sub-pixels. 
         [0012]    The foregoing descriptions about the content of the present disclosure and the following descriptions of embodiments are intended to illustrate and explain the spirit and principle of the present disclosure and provide a further explanation of the patent application scope of the present disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The disclosure will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the disclosure, and wherein: 
           [0014]      FIG. 1  is a schematic diagram of an optical sensing circuit according to an embodiment of the present disclosure; 
           [0015]      FIG. 2A  and  FIG. 2B  are signal sequence diagrams related to  FIG. 1 ; 
           [0016]      FIG. 3  is a schematic diagram of an optical sensing circuit according to another embodiment of the present disclosure; 
           [0017]      FIG. 4  is a signal sequence diagram corresponding to  FIG. 3 ; 
           [0018]      FIG. 5  is a schematic diagram of an optical sensing circuit according to another embodiment of the present disclosure; 
           [0019]      FIG. 6A  and  FIG. 6B  are signal sequence diagrams related to  FIG. 5 ; 
           [0020]      FIG. 7  is a schematic diagram of an optical sensing circuit according to another embodiment of the present disclosure; 
           [0021]      FIG. 8  is a schematic diagram of an optical sensing circuit according to another embodiment of the present disclosure; 
           [0022]      FIG. 9  is a schematic diagram of an optical sensing circuit according to still another embodiment of the present disclosure; 
           [0023]      FIG. 10  is a schematic diagram of an optical sensing circuit and a pixel configuration according to an embodiment of the present disclosure; 
           [0024]      FIG. 11  is a schematic diagram of a time-division optical sensing circuit according to an embodiment of the present disclosure; and 
           [0025]      FIG. 12  is a signal sequence diagram corresponding to  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    Specific features and advantages of the present disclosure are described in detail in the following embodiments. Content thereof is sufficient for any person skilled in the art to understand and implement the technical content of the present disclosure, and any person skilled in the art can easily understand a related objective and the advantages of the present disclosure according to the content, claims, and drawings that are disclosed in this specification. The following embodiments are intended to further describe the ideas of the present disclosure in detail, and are not intended to limit the scope of the present disclosure to any of the ideas. 
         [0027]    Refer to  FIG. 1 , which is a schematic diagram of an optical sensing circuit according to an embodiment of the present disclosure. As shown in  FIG. 1 , an optical sensing circuit  1000  according to an embodiment of the present disclosure has first color filtering components CF 1 , CF 2 , and CF 4 , second color filtering components CF 3  and CF 5 , a first photosensitive transistor switch T 1 , a capacitor C 1 , a sampling circuit TSH, a second photosensitive transistor switch T 2 , a third photosensitive transistor switch T 3 , a fourth photosensitive transistor switch T 4 , and a fifth photosensitive transistor switch T 5 . The first color filtering components CF 1 , CF 2 , and CF 4  can block light except first colored light. The second color filtering components CF 3  and CF 5  block light except second colored light, where the first colored light and the second colored light are different from each other. In this embodiment, the first colored light is, for example, about red light, and the second colored light is, for example, about blue light. In an embodiment, the first color filtering components are separate entities, while in another embodiment, the first color filtering components CF 1 , CF 2 , and CF 4  are actually parts of a red color filter, and similarly, the second color filtering components CF 3  and CF 5  are parts of a blue color filter. 
         [0028]    The first photosensitive transistor switch T 1  is arranged opposite to the first color filtering component CF 1 , and has a first end and a second end. Using  FIG. 1  as an example, the first end is an upper end and the second end is a lower end. Besides, the first photosensitive transistor switch T 1  also has a control end (gate). Specifically, using an example in which the first photosensitive transistor switch T 1  is an N-type thin-film transistor, when a voltage G_TP(t) of the control end of the first photosensitive transistor switch T 1  is a high voltage VGH, the first photosensitive transistor switch T 1  is turned on, so that charges can flow between the first end and the second end. When the gate voltage of the first photosensitive transistor switch T 1  is a low voltage VGL, if the first photosensitive transistor switch T 1  is not exposed to light, the first photosensitive transistor switch T 1  is not turned on. Conversely, if the first photosensitive transistor switch T 1  is exposed to light, the first photosensitive transistor switch T 1  is turned on. In this embodiment, because the first photosensitive transistor switch T 1  is arranged opposite to the first color filtering component CF 1  and the first color filtering component CF 1  is a red color filter, if light falling on the first color filtering component CF 1  does not include red light, no light can penetrate through the first color filtering component CF 1  to trigger the turning on of the first photosensitive transistor switch T 1 . Only when light falling on the first color filtering component CF 1  includes red light, can red light penetrate through the first color filtering component CF 1  to trigger the turning on of the first photosensitive transistor switch T 1 . 
         [0029]    The capacitor C 1  is separately electrically connected to the first end of the first photosensitive transistor switch T 1  and a first voltage end N 1 . The first voltage end N 1  may be at a ground potential (GND) or a pixel-sharing potential (VCOM). Therefore, a sensing voltage VA of the first end of the first photosensitive transistor switch T 1  can be stored in the capacitor C 1  in forms of charges. 
         [0030]    The sampling circuit TSH is electrically connected to the first end of the first photosensitive transistor switch T 1 . The sampling circuit TSH is configured to read the sensing voltage VA in a sampling time interval. Although a switch is used to implement the sampling circuit in this embodiment, many common means in the field of signal processing can also be used as the sampling circuit, such as a sense amplifier for memory reading, a pre-amplification circuit (pre-amplifier) in an analog-to-digital conversion circuit, or another circuit suitable for continuous or discrete sampling of the sensing voltage VA, which are not limited in the present disclosure. It should be noted that, using the transistor switch T 1  of the sampling circuit TSH in  FIG. 1  as an example, the sampling circuit TSH only has an on/off or switching capability, and does not have a capability of sensing colored light, and another type of sampling circuit is selected still according to this manner. 
         [0031]    The second photosensitive transistor switch T 2  is arranged opposite to the first color filtering component CF 2 , and has a control end (gate), a first end (an upper end), and a second end (a lower end), where the first end of the second photosensitive transistor switch T 2  is electrically connected to the second end of the first photosensitive transistor switch T 1 , and the control end of the second photosensitive transistor switch T 2  is electrically connected to the second end of the second photosensitive transistor switch T 2 . 
         [0032]    The third photosensitive transistor switch T 3  is arranged opposite to the second color filtering component CF 3 , and has a control end (gate), a first end (an upper end), and a second end (a lower end), where both of the first end of the third photosensitive transistor switch T 3  and the control end of the third photosensitive transistor switch T 3  are electrically connected to the second end of the first photosensitive transistor switch T 1 , and the second end of the third photosensitive transistor switch T 3  is electrically connected to a voltage source VSH. The second photosensitive transistor switch T 2  and the third photosensitive transistor switch T 3  form a first ambient light sensing circuit E 1  in an embodiment of the present disclosure. 
         [0033]    The fourth photosensitive transistor switch T 4  is arranged opposite to the first color filtering component CF 4 , and has a control end (gate), a first end (an upper end), and a second end (a lower end), where the first end of the fourth photosensitive transistor switch T 4  is electrically connected to the second end of the second photosensitive transistor switch T 2 , and both of the control end of the fourth photosensitive transistor switch T 4  and the second end of the fourth photosensitive transistor switch T 4  are electrically connected to a first signal end Sn(t). 
         [0034]    The fifth photosensitive transistor switch T 5  is arranged opposite to the second color filtering component CF 5 , and has a control end (gate), a first end (an upper end), and a second end (a lower end), where both of the first end of the fifth photosensitive transistor switch T 5  and the control end of the fifth photosensitive transistor switch T 5  are electrically connected to the second end of the second photosensitive transistor switch T 2 , and the second end of the fifth photosensitive transistor switch T 5  is electrically connected to a voltage source VSH. The fourth photosensitive transistor switch T 4  and the fifth photosensitive transistor switch T 5  form a second ambient light sensing circuit E 2  in an embodiment of the present disclosure. 
         [0035]    Refer to  FIG. 2A  and  FIG. 2B , which are signal sequence diagrams related to  FIG. 1 . It should be noted that, in this embodiment, a voltage source VSH is at about a high voltage VSH. In  FIG. 2A , the color filtering components are exposed to red light. In  FIG. 2B , the color filtering components are exposed to white light. As shown in  FIG. 2A , in a pre-charging time interval P 1 , the gate voltage G_TP(t) of the first photosensitive transistor switch T 1  is about a high voltage VGH, and the first signal end Sn(t) is at about the high voltage VSH; therefore, the first photosensitive transistor switch T 1 , the second photosensitive transistor switch T 2 , and the fourth photosensitive transistor switch T 4  are all turned on. Therefore, the sensing voltage VA will increase to near the high voltage VSH. Then, in a switching time interval P 2 , the gate voltage G_TP(t) of the first photosensitive transistor switch T 1  switches to about a low voltage VGL, to alleviate transistor aging caused when the gate voltage of the first photosensitive transistor switch T 1  remains at about the high voltage VSH for a long time, but the first signal end Sn(t) still remains at about the high voltage VSH. In a sensing time interval P 3 , the first signal end Sn(t) switches to about a low voltage VSL. Because the first color filtering components CF 1 , CF 2 , and CF 4  and the second color filtering components CF 3  and CF 5  are all exposed to red light, the first photosensitive transistor switch T 1 , the second photosensitive transistor switch T 2 , and the fourth photosensitive transistor switch T 4  are turned on under the effect of light. In the sensing time interval P 3 , because of the connection manners of the third photosensitive transistor switch T 3  and the fifth photosensitive transistor switch T 5 , and because neither of the two photosensitive transistor switches is triggered by light, the two photosensitive transistor switches are not turned on. Therefore, the sensing voltage VA will decrease to the voltage of the first signal end Sn(t), that is, about the low voltage VSL. In a sampling time interval P 4 , a control signal Gn(t) of the sampling circuit switches from about the low voltage VGL to about the high voltage VGH, so as to perform sampling on the sensing voltage VA, to obtain the low voltage VSL, and therefore, it is determined that the optical sensing circuit is exposed to red light. 
         [0036]    In an example in  FIG. 2B , in a sensing time interval P 3 , because the color filtering components are exposed to white light, red light penetrates through the first color filtering components CF 1 , CF 2 , and CF 4 , and blue light penetrates through the second color filtering components CF 3  and CF 5 . Therefore, all the photosensitive transistor switches are turned on under the effect of light. Therefore, a voltage value of the sensing voltage VA will not decrease to the low voltage VSL. In some embodiments, through proper design, channel widths of the third photosensitive transistor switch T 3  and the fifth sensing transistor switch T 5  are greater than those of the second photosensitive transistor switch T 2  and the fourth photosensitive transistor switch T 4 , and therefore, the voltage value of the sensing voltage VA will be even close to the voltage (the high voltage VSH) of the voltage source VSH. Although the second color filtering components CF 3  and CF 5  in the forgoing embodiment are blue color filters, actually, the second color filtering components may also be green color filters or filters of other colors (except red). 
         [0037]    In terms of action mechanism, using the second photosensitive transistor switch T 2  as an example, in the sensing time interval P 3 , a current  12  that flows through the second photosensitive transistor switch T 2  to the first photosensitive transistor switch T 1  is about proportional to a product of a luminous flux LR of red light and the channel width of the second photosensitive transistor switch T 2 . Using the third photosensitive transistor switch T 3  as an example, in the sensing time interval P 3 , a current  13  that flows through the third photosensitive transistor switch T 3  to the first photosensitive transistor switch T 1  is about proportional to a product of a luminous flux LB of blue light and the channel width of the third photosensitive transistor switch T 3 . The same is true for the fourth photosensitive transistor switch T 4  and the fifth photosensitive transistor switch T 5 . Therefore, through proper design, the sensing voltage VA will decrease to the low voltage VSL in the sensing time interval P 3  only when a ratio of the luminous flux of red light to the luminous flux of blue light is greater than a threshold. The threshold is, for example, 2. However, a person with common knowledge in the field can freely design a value of the threshold, and the threshold is not limited to 2 in the present disclosure. Therefore, in an environment in which ambient light also exists, when the optical sensing circuit  1000  is exposed to only ambient light, although the second photosensitive transistor switch T 2  and the third photosensitive transistor switch T 3  are turned on simultaneously, a current that flows through the second photosensitive transistor switch T 2  (and the fourth photosensitive transistor switch T 4 ) to the first signal end Sn(t) is soon compensated by a current that is provided by the voltage source and that flows through the third photosensitive transistor T 3 , so that the voltage in the sensing voltage VA does not decrease obviously. 
         [0038]    In other words, in the foregoing embodiment, both of the first ambient light sensing circuit E 1  and the second ambient light sensing circuit E 2  have two input ends (lower ends) and one output end (an upper end). In any one of the ambient light sensing circuits, one input end is selectively electrically connected to the output end according to whether red light is sensed, and the other input end is selectively electrically connected to the output end according to whether blue light is sensed. In addition, through particular design of a time sequence of the voltages of the voltage source VSH and the first signal end Sn(t), a voltage value of the sensing voltage VA corresponding to red light (monochromatic light) is different from a voltage value corresponding to white light or polychromatic light. 
         [0039]    Through the foregoing design, an optical sensing circuit insensitive to ambient light is implemented. Besides, the second photosensitive transistor switch T 2  degrades only when the fourth photosensitive transistor switch T 4  has already degraded and remains in a turned-on state permanently. Therefore, a service life and reliability of the optical sensing circuit implemented according to this embodiment are ensured. 
         [0040]    In an embodiment, also referring to  FIG. 1 , the first ambient light sensing circuit E 1  further has a sixth photosensitive transistor switch T 6 , and the sixth photosensitive transistor switch T 6  is arranged opposite to a third color filtering component CF 6 . In this embodiment, when the first color filtering components are all red color filters and the second color filtering components are all blue color filters, the third color filtering component CF 6  is a green color filter. 
         [0041]    In another embodiment of the present disclosure, refer to  FIG. 3 , which is a schematic diagram of an optical sensing circuit according to another embodiment of the present disclosure. As shown in  FIG. 3 , a difference between an optical sensing circuit  1000 ′ and the optical sensing circuit  1000  in  FIG. 1  lies in: a control end of a first photosensitive transistor switch T 1  is electrically connected to a first end of the first photosensitive transistor switch T 1 , a control end of a second photosensitive transistor switch T 2  is electrically connected to a first end of the second photosensitive transistor switch T 2 , a control end of a third photosensitive transistor switch T 3  is electrically connected to a second end of the third photosensitive transistor switch T 3 , a control end of a fourth photosensitive transistor switch T 4  is electrically connected to a first end of the fourth photosensitive transistor switch T 4 , and a control end of a fifth photosensitive transistor switch T 5  is electrically connected to a second end of the fifth photosensitive transistor switch T 5 . Besides, a voltage source is a VSL, and a voltage of the voltage source is about a low voltage VSL. The foregoing optical sensing circuit  1000  in  FIG. 1  may be referred to as a discharging mode optical sensing circuit, while the optical sensing circuit  1000 ′ in  FIG. 3  may be referred to as a charging mode optical sensing circuit. In an embodiment, a control end of a sixth photosensitive transistor switch T 6  is electrically connected to a second end of the sixth photosensitive transistor switch T 6 . 
         [0042]    Refer to  FIG. 4 , which is a signal sequence diagram corresponding to  FIG. 3 . As shown in  FIG. 4 , in a pre-charging time interval P 1  and a switching time interval P 2 , a voltage of a first signal end Sn(t) is a low voltage VSL; therefore, the first photosensitive transistor switch T 1 , the second photosensitive transistor switch T 2 , and the fourth photosensitive transistor switch T 4  are all in a turned-on state because the switches are all diode-connected. Therefore, in the foregoing time intervals, the sensing voltage VA decreases to the low voltage VSL. Then, in a sensing time interval P 3 , the voltage of the first signal end Sn(t) switches to a high voltage VSH. In this case, if the color filtering components of the optical sensing circuit  1000 ′ are exposed to only red light, the first photosensitive transistor switch T 1 , the second photosensitive transistor switch T 2 , and the fourth photosensitive transistor switch T 4  are turned on under the effect of light, while the third photosensitive transistor switch T 3 , the fifth photosensitive transistor switch T 5 , and the sixth photosensitive transistor switch T 6  are not triggered and are therefore not turned on. Therefore, the sensing voltage VA will decrease to near the high voltage VSH, as shown in a signal sequence diagram of VA (corresponding light) in the figure. 
         [0043]    Conversely, if the voltage of the first signal end Sn(t) switches to the high voltage VSH in the sensing time interval P 3 , if the color filtering components of the optical sensing circuit  1000 ′ are exposed to white light, the first photosensitive transistor switch T 1 , the second photosensitive transistor switch T 2 , and the fourth photosensitive transistor switch T 4  are turned on under the effect of light, while the third photosensitive transistor switch T 3  and the fifth photosensitive transistor switch T 5  are turned on under the effect of blue light, and the sixth photosensitive transistor switch T 6  is turned on under the effect of green light. Therefore, the sensing voltage VA will not increase to near the high voltage VSH, but instead remains close to the low voltage VSL, as shown in a signal sequence diagram of VA (white light) in the figure. 
         [0044]    In the foregoing embodiment, the photosensitive transistor switches are used as parts of the sensing components, but it can be known that the diode-connected photosensitive transistor switches can be replaced by photo diodes (PD). A person with common knowledge in the field should know how to configure a photo diode to replace a photosensitive transistor switch, which is not described in detail in the present disclosure. 
         [0045]    For an optical sensing circuit according to another embodiment of the present disclosure, refer to  FIG. 5 , which is a schematic diagram of an optical sensing circuit according to another embodiment of the present disclosure. As shown in  FIG. 5 , an optical sensing circuit  3000  according to an embodiment of the present disclosure has a color filtering component CF 1 , a color filtering component CF 2 , a color filtering component CF 3 , a first photosensitive transistor switch T 1 , a capacitor C 1 , a sampling circuit TSH, a second photosensitive transistor switch T 2 , and a third photosensitive transistor switch T 3 . The color filtering component CF 1  blocks light except first colored light. The color filtering component CF 2  blocks light except second colored light. The color filtering component CF 3  blocks light except third colored light. The first colored light, the second colored light, and the third colored light are different from each other. In the following embodiment, an example in which the first colored light is about red light, the second colored light is about blue light, and the third colored light is about green light is used for description. 
         [0046]    The first photosensitive transistor switch T 1  is arranged opposite to the color filtering component CF 1 , and has a first end and a second end. Using  FIG. 5  as an example, the first end is an upper end and the second end is a lower end. Besides, the first photosensitive transistor switch T 1  also has a control end (gate). Specifically, using an example in which the first photosensitive transistor switch T 1  is an N-type thin-film transistor, when a voltage G_TP(t) of the control end of the first photosensitive transistor switch T 1  is about a high voltage VGH, the first photosensitive transistor switch T 1  is turned on, so that charges can flow between the first end and the second end. When the gate voltage of the first photosensitive transistor switch T 1  is about a low voltage VGL, if the first photosensitive transistor switch T 1  is not exposed to light, the first photosensitive transistor switch T 1  is not turned on. Conversely, if the first photosensitive transistor switch T 1  is exposed to light, the first photosensitive transistor switch T 1  is turned on. In this embodiment, because the first photosensitive transistor switch T 1  is arranged opposite to the color filtering component CF 1  and the color filtering component CF 1  is a red color filter, if light falling on the color filtering component CF 1  does not include red light, no light can penetrate through the color filtering component CF 1  to trigger the turning on of the first photosensitive transistor switch T 1 . Only when light falling on the color filtering component CF 1  includes red light, can the red light penetrate through the color filtering component CF 1  to trigger the turning on of the first photosensitive transistor switch T 1 . In other words, the first photosensitive transistor switch T 1  and the color filtering component CF 1  form a first sensing component. 
         [0047]    The capacitor C 1  is separately electrically connected to the first end of the first photosensitive transistor switch T 1  and a first voltage end N 1 . Therefore, a sensing voltage VA of the first end of the first photosensitive transistor switch T 1  can be stored in the capacitor C 1  in forms of charges. 
         [0048]    The sampling circuit TSH is electrically connected to the first end of the first photosensitive transistor switch T 1 . The sampling circuit TSH is configured to read the sensing voltage VA in a sampling time interval. Although a switch is used to implement the sampling circuit in this embodiment, many common means in the field of signal processing can also be used as the sampling circuit, such as a sense amplifier for memory reading, a pre-amplification circuit (pre-amplifier) in an analog-to-digital conversion circuit, or another circuit suitable for continuous or discrete sampling of the sensing voltage VA, which are not limited in the present disclosure. It should be noted that, using the transistor switch T 1  of the sampling circuit TSH in  FIG. 1  as an example, the sampling circuit TSH only has an on/off or switching capability, and does not have a capability of sensing colored light, and another type of sampling circuit is selected still according to this manner. 
         [0049]    The second photosensitive transistor switch T 2  is arranged opposite to the color filtering component CF 2 , and has a control end (gate), a first end (an upper end), and a second end (a lower end), where the first end of the second photosensitive transistor switch T 2  is electrically connected to the second end of the first photosensitive transistor switch T 1 , the control end of the second photosensitive transistor switch T 2  is electrically connected to the second end of the second photosensitive transistor switch T 2 , and the second end of the second photosensitive transistor switch T 2  is electrically connected to a first signal end Sn(t). The second photosensitive transistor switch T 2  and the color filtering component CF 2  form a second sensing component. 
         [0050]    The third photosensitive transistor switch T 3  is arranged opposite to the color filtering component CF 3 , and has a control end (gate), a first end (an upper end), and a second end (a lower end), where both of the first end of the third photosensitive transistor switch T 3  and the control end of the third photosensitive transistor switch T 3  are electrically connected to the second end of the first photosensitive transistor switch T 1 , and the second end of the third photosensitive transistor switch T 3  is electrically connected to a voltage source VSH. The third photosensitive transistor switch T 3  and the color filtering component CF 3  form a third sensing component. 
         [0051]    Then, refer to  FIG. 6A  and  FIG. 6B , which are signal sequence diagrams related to  FIG. 5 . It should be noted that, in this embodiment, a voltage source VSH is at about a high voltage VSH. In  FIG. 6A , the color filtering components are exposed to light that includes red light and blue light. In  FIG. 6B , the color filtering components are exposed to white light. As shown in  FIG. 6A , in a pre-charging time interval P 1 , the gate voltage G_TP(t) of the first photosensitive transistor switch T 1  is about a high voltage VGH, and the first signal end Sn(t) is about at the high voltage VSH; therefore, both of the first photosensitive transistor switch T 1  and the second photosensitive transistor switch T 2  are turned on. Therefore, the sensing voltage VA will increase to near the high voltage VSH. Then, in a switching time interval P 2 , the gate voltage G_TP(t) of the first photosensitive transistor switch T 1  switches to about the low voltage VGL, to alleviate transistor aging caused when the gate voltage of the first photosensitive transistor switch T 1  remains at the high voltage VSH for a long time. In a sensing time interval P 3 , the first signal end Sn(t) switches to about the low voltage VSL. Because the color filtering component CF 1  to the color filtering component CF 3  are all exposed to red light and blue light, both of the first photosensitive transistor switch T 1  and the second photosensitive transistor switch T 2  are turned on under the effect of light. In the sensing time interval P 3 , because of the connection manner of the third photosensitive transistor switch T 3 , and because the third photosensitive transistor switch T 3  is not triggered by light, the third photosensitive transistor switch T 3  is not turned on. Therefore, the sensing voltage VA will decrease to about the voltage of Sn(t), that is, the low voltage VSL. In a sampling time interval P 4 , a control signal Gn(t) of the sampling circuit switches from the low voltage VGL to the high voltage VGH, so as to perform sampling on the sensing voltage VA, to obtain the low voltage VSL, and therefore, it is determined that the optical sensing circuit is exposed both to red light and blue light. 
         [0052]    In the example in  FIG. 6B , in the sensing time interval P 3 , because the color filtering components are exposed to white light, red light penetrates through the color filtering component CF 1 , blue light penetrates through the color filtering component CF 2 , and green light penetrates through the color filtering component CF 3 . Therefore, all the photosensitive transistor switches are turned on under the effect of light. Therefore, a voltage value of the sensing voltage VA will not decrease to the low voltage VSL. In some embodiments, through proper design, a channel width of the third photosensitive transistor switch T 3  is greater than that of the second photosensitive transistor switch T 2 , and the voltage value of the sensing voltage VA will be even close to the voltage (high voltage VSH) of the voltage source VSH. 
         [0053]    In terms of action mechanism, using the second photosensitive transistor switch T 2  as an example, in the sensing time interval P 3 , a current  12  that flows through the second photosensitive transistor switch T 2  to the first photosensitive transistor switch T 1  is about proportional to a product of a luminous flux LB of blue light and the channel width of the second photosensitive transistor switch T 2 . Using the third photosensitive transistor switch T 3  as an example, in the sensing time interval P 3 , a current  13  that flows through the third photosensitive transistor switch T 3  to the first photosensitive transistor switch T 1  is about proportional to a product of a luminous flux LG of green light and the channel width of the third photosensitive transistor switch T 3 . Therefore, through proper design, the sensing voltage VA will decrease to the low voltage VSL in the sensing time interval P 3  only when a ratio of the luminous flux of blue light to the luminous flux of green light is greater than a threshold. 
         [0054]    In another embodiment, refer to  FIG. 7 , which is a schematic diagram of an optical sensing circuit according to another embodiment of the present disclosure. As shown in  FIG. 7 , a difference between the optical sensing circuit  3000 ′ and the optical sensing circuit  3000  in  FIG. 5  lies in: a control end of a first photosensitive transistor switch T 1  is electrically connected to a first end of the first photosensitive transistor switch T 1 , a control end of a second photosensitive transistor switch T 2  is electrically connected to a first end of the second photosensitive transistor switch T 2 , a control end of a third photosensitive transistor switch T 3  is electrically connected to a second end of the third photosensitive transistor switch T 3 . Besides, a voltage source is about a VSL, and a voltage of the voltage source is about a low voltage VSL. The foregoing optical sensing circuit  3000  in  FIG. 5  may be referred to as a discharging mode optical sensing circuit, while the optical sensing circuit  3000 ′ in  FIG. 7  may be referred to as a charging mode optical sensing circuit. 
         [0055]    Refer to  FIG. 4  again, to understand a sequence of signals in  FIG. 7 . As shown in  FIG. 4 , in a pre-charging time interval P 1  and a switching time interval P 2 , a voltage of a first signal end Sn(t) is about a low voltage VSL, and both of the first photosensitive transistor switch T 1  and the second photosensitive transistor switch T 2  are in a turned-on state because the switches are diode-connected. Therefore, in the foregoing time intervals, the sensing voltage VA decreases to the low voltage VSL. Then, in a sensing time interval P 3 , the voltage of the first signal end Sn(t) switches to a high voltage VSH. In this case, if the color filtering components of the optical sensing circuit  3000 ′ are exposed to only purple light, the first photosensitive transistor switch T 1  is turned on under the effect of red light, the second photosensitive transistor switch T 2  is turned on under the effect of blue light, and the third photosensitive transistor switch T 3  is not triggered by light and is therefore not turned on. Therefore, the sensing voltage VA will increase to near the high voltage VSH, as shown in a signal sequence diagram of VA (corresponding light) in the figure. 
         [0056]    Conversely, if the voltage of the first signal end Sn(t) switches to about the high voltage VSH in the sensing time interval P 3 , if the color filtering components of the optical sensing circuit  3000 ′ are exposed to white light, the first photosensitive transistor switch T 1  is turned on under the effect of red light, the second photosensitive transistor switch T 2  is turned on under the effect of blue light, and the third photosensitive transistor switch T 3  is turned on under the effect of green light. Therefore, the sensing voltage VA will not increase to near the high voltage VSH, but instead remains close to the low voltage VSL, as shown in a signal sequence diagram of VA (white light) in the figure. 
         [0057]    In a further embodiment, refer to  FIG. 8 , which is a schematic diagram of an optical sensing circuit according to another embodiment of the present disclosure. As shown in  FIG. 8 , compared with the optical sensing circuit  3000  in  FIG. 5 , an optical sensing circuit  5000  further includes a color filtering component CF 4 , a fourth photosensitive transistor switch T 4 , a first switch TSW 1 , and a second switch TSW 2 . A first end (an upper end) of a second photosensitive transistor switch T 2  is electrically connected to a second end (a lower end) of a first photosensitive transistor switch T 1  through the first switch TSW 1 , that is, a control end of the first switch TSW 1  is electrically connected to a selection signal SW 1 , a second end (a lower end) of the first switch TSW 1  is electrically connected to the first end (the upper end) of the second photosensitive transistor switch T 2 , and a first end (an upper end) of the first switch TSW 1  is electrically connected to the second end of the first photosensitive transistor switch T 1 . A first end (an upper end) of the fourth photosensitive transistor switch T 4  is electrically connected to the second end of the first photosensitive transistor switch T 1  through the second switch TSW 2 , that is, a control end of the second switch TSW 2  is electrically connected to a selection signal SW 2 , a second end (a lower end) of the second switch TSW 2  is electrically connected to the first end (upper end) of the fourth photosensitive transistor switch T 4 , and a first end (an upper end) of the second switch TSW 2  is electrically connected to the second end of the first photosensitive transistor switch T 1 . Besides, a color filtering component CF 1  and the color filtering component CF 4  filter out light except first colored light, a color filtering component CF 2  filters out light except second colored light, a color filtering component CF 3  filters out light except third colored light, the fourth photosensitive transistor switch T 4  is arranged opposite to the color filtering component CF 4 , and the first switch TSW 1  and the second switch TSW 2  form a selection circuit. 
         [0058]    For example, when the selection signals SW 1  and SW 2  determine that the first switch TSW 1  is turned on and the second switch TSW 2  is not turned on, whether the fourth photosensitive transistor switch T 4  is triggered by light or not, actuation of the fourth photosensitive transistor switch T 4  does not affect a sensing voltage VA. In this case, actuation of the optical sensing circuit is actually the same as that of the optical sensing circuit  3000  shown in  FIG. 5 . When the second switch TSW 2  is turned on and the first switch TSW 1  is not turned on, whether the second photosensitive transistor switch T 2  is triggered by light or not, actuation of the second photosensitive transistor switch T 2  does not affect the sensing voltage VA. In this case, the actuation of the optical sensing circuit and a change in the sensing voltage VA are actually determined by whether the first photosensitive transistor switch T 1 , the third photosensitive transistor switch T 3 , and the fourth photosensitive transistor switch T 4  are turned on. In an embodiment in which the first colored light is about red light, the second colored light is about blue light, and the third colored light is about green light, the optical sensing circuit  5000  selectively senses red light or purple light according to the selection signals SW 1  and SW 2 . 
         [0059]    In the embodiment shown in  FIG. 8 , the selection circuit formed by the first switch TSW 1  and the second switch TSW 2  selectively electrically connects the second photosensitive transistor switch T 2  or the fourth photosensitive transistor switch T 4  to the first photosensitive transistor switch T 1 . However, in another embodiment, the second photosensitive transistor switch T 2  is electrically connected to a first signal end Sn(t) through the first switch TSW 1 , and the fourth photosensitive transistor switch T 4  is electrically connected to the first signal end Sn(t) through the second switch TSW 2 . In other words, the selection circuit selectively electrically connects the first signal end Sn(t) to the second photosensitive transistor switch T 2  or the fourth photosensitive transistor switch T 4 . 
         [0060]    In another embodiment, refer to  FIG. 9 , which is a schematic diagram of an optical sensing circuit according to still another embodiment of the present disclosure. As shown in  FIG. 9 , compared with the optical sensing circuit  5000  in  FIG. 8 , an optical sensing circuit  6000  further has a fifth photosensitive transistor switch T 5  and a color filtering component CF 5 . A first end (an upper end) of the fifth photosensitive transistor switch T 5  is electrically connected to a first end of a first photosensitive transistor switch T 1 , a second end (a lower end) of the fifth photosensitive transistor switch T 5  is electrically connected to a second end of the first photosensitive transistor switch T 1 , and the fifth photosensitive transistor switch T 5  is arranged opposite to the color filtering component CF 5 . A color filtering component CF 1  and a color filtering component CF 4  filter out light except first colored light, a color filtering component CF 2  and the color filtering component CF 5  filter out light except second colored light, and a color filtering component CF 3  filters out light except third colored light. Therefore, the optical sensing circuit shown in  FIG. 9  can sense pure blue light, pure red light, or purple light (light including red light and blue light) under the control of a selection signal SW 1  and a selection signal SW 2 . 
         [0061]    In an embodiment, both of the optical sensing circuit shown in  FIG. 1  and the optical sensing circuit shown in  FIG. 8  or  FIG. 9  are configured in a same pixel of a display device, and the first color filtering component of the optical sensing circuit shown in  FIG. 1  is configured as a green color filter, and the second color filtering component is configured as a red color filter, so that the optical sensing circuit senses green light. The optical sensing circuit shown in  FIG. 8  or  FIG. 9  is set to sense red light and purple light. 
         [0062]    Specifically, refer to  FIG. 10 , which is a schematic diagram of an optical sensing circuit and a pixel configuration according to an embodiment of the present disclosure. As shown in  FIG. 10 , in an embodiment of the present disclosure, a display panel includes a substrate (not shown), and has several pixel units (not marked). Each pixel unit includes at least three sub-pixels, for example, first, second, and third sub-pixels PX 1  to PX 3 . A red light sensing circuit SR and a blue light sensing circuit SB are configured in the first sub-pixel PX 1 , and a green light sensing circuit SG and a purple light sensing circuit SP (red+blue) are configured in the second sub-pixel PX 2  in the display panel. The first sub-pixel PX 1  is adjacent to the second sub-pixel PX 2 . 
         [0063]    Refer to  FIG. 11 , which is a schematic diagram of a time-division optical sensing circuit according to an embodiment of the present disclosure. As shown in  FIG. 11 , an optical sensing circuit  7000  has color filtering components CF 1  to CF 6 , a first switch TSW 1 , a second switch TSW 2 , a capacitor C 1 , a sampling circuit TSH, a first photosensitive transistor switch T 1 , a second photosensitive transistor switch T 2 , a third photosensitive transistor switch T 3 , a fourth photosensitive transistor switch T 4 , a fifth photosensitive transistor switch T 5 , and a sixth photosensitive transistor switch T 6 . When the optical sensing circuit  7000  is configured in the first sub-pixel PX 1 , the color filtering components CF 1  and CF 2  are set to block light except first colored light. The color filtering components CF 4  and CF 5  block light except second colored light. The color filtering components CF 3  and CF 6  block light except third colored light. The first colored light, the second colored light, and the third colored light are different from each other. When the optical sensing circuit  7000  is configured in the first sub-pixel PX 1 , the first colored light is about, for example, red light, the second colored light is about, for example, blue light, and the third colored light is about, for example, green light. That is, in the embodiment in which the optical sensing circuit  7000  is configured in the first sub-pixel PX 1 , the color filtering components CF 1  to CF 3  and the photosensitive transistor switches T 1  to T 3  are used as an optical sensing circuit corresponding to red light, that is, corresponding to the red light sensing circuit SR in  FIG. 10 , while the color filtering components CF 4  to CF 6  and the photosensitive transistor switches T 4  to T 6  are used as an optical sensing circuit corresponding to blue light, that is, corresponding to the blue light sensing circuit SB in  FIG. 10 . In an embodiment, the first color filtering components are separate entities, while in another embodiment, the first color filtering components CF 1  and CF 2  are actually parts of a red color filter, and similarly, the second color filtering components CF 4  and CF 5  are parts of a blue color filter, and the third color filtering component CF 3  and CF 6  are parts of a green color filter. 
         [0064]    If the optical sensing circuit  7000  is configured in the second sub-pixel PX 2  in  FIG. 10 , the color filtering components CF 1 , CF 2  and CF 6  are configured to block light except third colored light. The color filtering component CF 5  blocks light except second colored light. The color filtering components CF 3  and CF 4  block light except first colored light. The first colored light, the second colored light, and the third colored light are different from each other. The first colored light is about, for example, red light, the second colored light is about, for example, blue light, and the third colored light is about, for example, green light. That is, when the optical sensing circuit  7000  is configured in the second sub-pixel PX 2 , the color filtering components CF 1  to CF 3  and the photosensitive transistor switches T 1  to T 3  are used as an optical sensing circuit corresponding to green light, that is, corresponding to the green light sensing circuit SG in  FIG. 10 , while the color filtering components CF 4  to CF 6  and the photosensitive transistor switches T 4  to T 6  are used as an optical sensing circuit corresponding to purple light including red light and blue light, that is, corresponding to the purple light sensing circuit SP in  FIG. 10 . 
         [0065]    In other embodiments, one of the optical sensing circuits in the forgoing embodiments may be used in at least one of the three sub-pixels or even all the three sub-pixels. Alternatively, for at least two of the three sub-pixels, an optical sensing circuit in the first sub-pixel, may be one of the optical sensing circuits in the foregoing embodiments, and the optical sensing circuit in the second or third sub-pixel may be other types of optical sensing circuits in the foregoing embodiments except the optical sensing circuit used in the first sub-pixel. Alternatively, optical sensing circuits in at least three sub-pixels may be three different types of optical sensing circuits in the foregoing embodiments. It should be noted that the sub-pixels of the display panel have displaying and optical sensing capabilities. In addition, at least three sub-pixels may selectively cover three types of color filters, and colors of the color filters covered by the sub-pixels may be substantially the same as or different from those of color filtering components of optical sensing circuits in the sub-pixels. 
         [0066]    Refer to  FIG. 12 , which is a signal sequence diagram corresponding to  FIG. 11 . As shown in  FIG. 12 , a selection signal SW 1  controlling a first switch TSW 1  is the opposite of a falling edge of control signal Gn(t), and a selection signal SW 2  controlling a second switch TSW 2  is the opposite of the selection signal SW 1 . A frequency of a scan indication signal SCAN is the half of a frequency of the control signal Gn(t). In an embodiment in which the optical sensing circuit  7000  is configured in the first sub-pixel PX 1 , each scan section of the optical sensing circuit  7000  includes a first scan section PR (red light) and a second scan section PB (blue light). In the first scan section PR, the selection signal SW 1  causes the first switch TSW 1  to be turned on, and the selection signal SW 2  causes the second switch TSW 2  to be turned off. Therefore, the optical sensing circuit  7000  is used to sense red light. In the second scan section PB, the selection signal SW 1  causes the first switch TSW 1  to be turned off, and the selection signal SW 2  causes the second switch TSW 2  to be turned on. Therefore, the optical sensing circuit  7000  is used to sense red light. In the sections, for actuation of the signals and the components, reference may be made to  FIG. 2A  and  FIG. 2B , which are not described repeatedly herein. 
         [0067]    Through the configurations shown in  FIG. 10  to  FIG. 12 , four types of light (red light, blue light, green light, and purple light) can be sensed in a range of two sub-pixels. Therefore, a minimum pitch of optical sensing of the implemented optical sensing display device is low, so as to improve sensing precision of the display device. Besides, through the circuit shown in  FIG. 11  plus the sequence diagram shown in  FIG. 12 , two optical sensing circuits located in a same sub-pixel actually share one capacitor and one sampling circuit. In one pixel, an area occupied by the optical sensing circuits is reduced, so as to increase an aperture ratio. 
         [0068]    Besides, in another embodiment, through the optical sensing circuit in  FIG. 8 , a circuit sensing monochromatic light and mixed light can be implemented in one circuit, for example, the red and purple light sensing circuit used as an example in  FIG. 8 . A blue and cyan light sensing circuit (cyan light is a mixture of blue light and green light) can be implemented in the same manner, and a green and yellow light sensing circuit (yellow light is a mixture of green light and red light) can also be implemented. Therefore, when the foregoing optical sensing circuits are respectively configured in the first sub-pixel PX 1 , the second sub-pixel PX 2 , and the third sub-pixel PX 3 , six types of light can be sensed in a range of three sub-pixels. 
         [0069]    In conclusion, according to the optical sensing circuit in the foregoing embodiments of the present disclosure, through the configuration of circuit connections, functions of excluding ambient light and sensing mixed light can be implemented. 
         [0070]    Although the foregoing embodiments of the present disclosure are disclosed above, they are not intended to limit the present invention. All variations and modifications made without departing the spirit and scope of the present invention fall within the patent protection scope of the present invention. For the protection scope of the present invention, refer to the claims.