Method for driving display device, display device driving apparatus, display device and display method

Abstract

The present invention provides a method for driving a display device (100), which improves the quality of captured images while maintaining the resolution of OLEDs. The display device (100) includes: a storage unit for storing a plurality of frame modes to be displayed in an object sensing area where an object is detected; and a light receiving element for detecting the object based on light from the light emitting element. The method includes: for each of the plurality of frame modes, scanning the pattern image, wherein the scanning includes: within the displayed frame mode, stopping the emission of the light emitting element on a portion of the emission signal lines arranged along a first axis; within the displayed frame mode, moving the emission signal lines to be prohibited from emission along the second axis; and measuring the reflected light from the object based on the emission of the light emitting element through the light receiving element.

Description

Technical Field

[0001] The embodiments of the present application relate to an image sensing function, and more particularly to a method for driving a photon detector, a photon detector driving device, a display method, and a display device. Background Art

[0002] Currently, the pixel unit driving circuit for portable terminal OLED includes a 6T1C (6 transistors and 1 capacitor) circuit and a 7T1C (7 transistors and 1 capacitor) circuit for each pixel. As the number of transistors implemented for one pixel increases in this way, the integration increases, while the corresponding resolution decreases.

[0003] In addition, an image sensor that converts light into an electrical signal is installed in the portable terminal. Specifically, an in-cell image sensor is known, in which a part (or all) of an image sensor mechanism (e.g., a CMOS sensor) for converting light into an electrical signal is incorporated into the TFT of the OLED. Typically, the image sensor includes an active pixel sensor (APS) that increases the gain of a signal pixel by pixel to increase the signal-to-noise ratio (S / N ratio). The structure of the APS includes three TFTs for each pixel: a reset transistor for resetting the voltage of a photodiode (PD) as a light receiving element, an amplifier transistor for amplifying the gain, and a transistor (or read transistor) for reading a signal. Therefore, when the pixel circuit is configured by implementing both a pixel unit driving circuit such as a 6T1C circuit or a 7T1C circuit and an image sensor for one pixel of the OLED, the circuit integration is further improved. Such a complex circuit configuration has an adverse effect on the corresponding resolution and reduces the space for adding other devices. Therefore, in order to simplify the circuit configuration, reference is made to Figure 2 It is known to remove the reset transistor and the amplifier transistor from the image sensor to provide a configuration including only a read transistor and a photodiode (1T1PD). However, the configuration without the amplifier transistor reduces the S / N ratio. Summary of the invention

[0004] The object of the present invention is to improve the quality of captured images while maintaining the resolution of the OLED.

[0005] A first aspect provides a method for driving a display device, wherein the display device comprises: a plurality of transmission signal lines, which are arranged along a first axis and respectively provide transmission signals to a plurality of light-emitting elements; a plurality of data signal lines, which are arranged along a second axis and provide data signals so that each of the plurality of light-emitting elements emits light; a storage unit, which stores a plurality of frame modes to be displayed in an object sensing area where an object is detected; and a light receiving element, which detects the object based on light from the light-emitting element, wherein the plurality of frame modes are designed according to the object, and the first axis and the second axis are perpendicular, and the method comprises, for each of the plurality of frame modes:

[0006] Scanning the pattern image, wherein the scanning comprises:

[0007] In a displayed frame mode, prohibiting emission of light emitting elements arranged along a portion of the emission signal lines;

[0008] In the frame mode of the display, moving the transmission signal line to be prohibited from transmitting along the second axis;

[0009] Reflected light from the object is measured by the light receiving element based on the emission of the light emitting element.

[0010] According to the implementation, for each of the plurality of frame modes, when scanning the pattern image, within the displayed frame mode, the emission of the light emitting elements arranged along a portion of the emission signal lines is prohibited, and within the displayed frame mode, the emission signal lines to be prohibited from emission are moved along the second axis. Therefore, the combination of the pattern illumination technology and the CDM driving method improves the quality of the captured image while maintaining the resolution of the OLED.

[0011] In combination with a possible implementation manner of the first aspect, the scanning includes scanning the pattern image only through light-emitting elements within a sensing area of ​​the object.

[0012] According to the implementation, since the pattern is only scanned by the light-emitting elements within the object sensing area, power consumption is avoided.

[0013] In combination with a possible implementation manner of the first aspect, the stopping of emission includes disabling light-emitting elements outside the object sensing area.

[0014] According to the implementation, by disabling the transmission signal line outside the object sensing area, power consumption is avoided.

[0015] In combination with a possible implementation manner of the first aspect, the reading of the light receiving element is controlled according to a reading signal of a scanning signal line, and the stopping of emission includes disabling the scanning signal line outside the object sensing area.

[0016] According to the implementation, the reading of the light receiving element is controlled according to the reading signal of the scanning signal line, and the scanning signal line outside the object sensing area is disabled while stopping the light emission, thereby avoiding power consumption waste.

[0017] In combination with a possible implementation manner of the first aspect, the stopping of emission includes simultaneously prohibiting emission of the light emitting element in a pattern image arranged along at least two adjacent emission signal lines.

[0018] According to the implementation, since emission of the light emitting element in the pattern image arranged along at least two adjacent emission signal lines is stopped, the CDM driving method is implemented by moving the optical fiber bundles controlled to disable the plurality of emission signal lines.

[0019] In combination with a possible implementation manner of the first aspect, the light receiving element is connected to a switch, and the measurement controls the switch so that the multiple light receiving elements connected to one data signal line are simultaneously connected to a photometric device.

[0020] According to the implementation, by removing one TFT from the PD circuit and connecting the PD circuit to an external switch, a simpler configuration can be achieved.

[0021] A second aspect provides a display device, including:

[0022] A plurality of transmission signal lines are arranged along the first axis and respectively provide transmission signals to the plurality of light emitting elements;

[0023] a plurality of data signal lines arranged along a second axis and providing a data signal to enable each of the plurality of light emitting elements to emit light, wherein the first axis is perpendicular to the second axis;

[0024] a storage unit storing a plurality of frame patterns to be displayed in an object sensing area where an object is detected, wherein the plurality of frame patterns are designed according to the object;

[0025] a light receiving element for detecting the object based on the light from the light emitting element;

[0026] A controller is configured to display the plurality of frame modes and display the mode image for each of the plurality of frame modes, wherein the displaying comprises:

[0027] In a display frame mode, stopping emission of light-emitting elements arranged along a portion of the emission signal lines;

[0028] In the frame mode of the display, moving the transmission signal line to be prohibited from transmitting along the second axis;

[0029] A photometric unit measures reflected light from the object based on the emission of the light emitting element detected by the light receiving element.

[0030] In combination with a possible implementation manner of the second aspect, the controller scans the pattern image only through the light-emitting elements in the object sensing area.

[0031] In combination with a possible implementation manner of the second aspect, the controller disables the light-emitting elements outside the object sensing area.

[0032] In a possible implementation manner in combination with the second aspect, the controller includes a plurality of gate on array (GOA) circuit substrates, and only the GOA that drives the light-emitting elements within the object sensing area is enabled.

[0033] According to the implementation, the controller is composed of a plurality of GOAs, and power consumption can be reduced by enabling only those GOAs that drive the light-emitting elements within the object sensing area and disabling the other GOAs.

[0034] In combination with a possible implementation manner of the second aspect, the light receiving element is read according to a read signal of a scanning signal line, and the controller disables the scanning signal line outside the object sensing area.

[0035] In combination with a possible implementation manner of the second aspect, the controller simultaneously prohibits the light emitting element from emitting in a pattern image arranged along at least two adjacent emission signal lines.

[0036] In combination with a possible implementation manner of the second aspect, the light receiving element is connected to a switch, and the controller controls the switch so that the multiple light receiving elements connected to one data signal line are simultaneously connected to the photometric device. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly describe the technical solutions in the embodiments of the present invention or the background technology, the following briefly describes the drawings required to be used in the description of the embodiments of the present invention or the background technology:

[0038] Figure 1 A block diagram of a configuration example of a display device provided for one embodiment;

[0039] Figure 2 A diagram showing a configuration example of a pixel circuit used in an OLED;

[0040] Figure 3 for Figure 2 A timing diagram showing an example of drive control of the pixel circuit shown;

[0041] Figure 4is a perspective view of a combination of a display and an image sensor;

[0042] Figure 5 A diagram showing the relationship between an array of OLED and PD and a subject;

[0043] Figure 6 for Figure 4 A diagram showing an example of patterned light moving in a horizontal direction;

[0044] Figure 7 is a diagram of an example of a frame mode for pattern illumination;

[0045] Figure 8 A diagram showing an example of pixel driving in fingerprint authentication;

[0046] Fig. 9 A diagram of a cross-sectional structure of a display with a finger placed on the display surface;

[0047] Fig.10 To virtually show Fig. 9 A graph showing the intensity of light received by the PD shown in;

[0048] Fig.11 A diagram of a cross-sectional structure of a display with a finger placed on the display surface provided for one embodiment;

[0049] Fig.12 For drawing Fig.11 A graph showing the intensity of light received by the PD;

[0050] Fig.13 A diagram of a frame mode provided for one embodiment;

[0051] Fig.14 A diagram showing an example of pixel driving in fingerprint authentication provided by an embodiment;

[0052] Fig.15 A diagram showing an example of pixel driving in fingerprint authentication provided by an embodiment;

[0053] Fig.16 A time variation diagram of a frame image provided by an embodiment;

[0054] Fig.17 A timing diagram showing an example of driving control of a pixel circuit provided by an embodiment;

[0055] Fig.18 A diagram showing an example configuration of a gate drive circuit;

[0056] Fig.19 A diagram showing an example configuration of a gate drive circuit;

[0057] Fig. 20A diagram showing an example of a configuration of a pixel circuit;

[0058] Fig.21 A timing diagram of driving control of a pixel circuit provided by an embodiment;

[0059] Fig. 22 A diagram showing the relationship between an array of OLED and PD and a subject;

[0060] Fig.23 A top view of a PD array in an image sensor provided according to an embodiment. DETAILED DESCRIPTION

[0061] The terms used in the embodiments of the present application are only used to explain the specific embodiments of the present application and are not used to limit the present application.

[0062] (First embodiment)

[0063] The first embodiment of the present invention is described below. In this embodiment, a code division multiplexing (CDM) driving method for driving an image sensor is combined with a pattern illumination technique.

[0064] Figure 1 A block diagram of a configuration example of a display device provided for a first embodiment of the present invention. The display device 100 includes a drive circuit 1. The pixel array 104 included in the drive circuit 1 has a plurality of pixel circuits arranged in a two-dimensional form (matrix form) of N rows × M columns. A vertical scanning circuit 101 that provides a pixel driving signal is arranged on one end side (the left side in the figure) of the pixel array 104. The pixel array 104 and the vertical scanning circuit 101 are connected by a signal line 102. In addition, a horizontal scanning circuit 107 and a signal converter 106 connected to each column signal line 105 are arranged on the lower end side (the lower side in the figure) of the imaging area.

[0065] The display device 10 includes a controller 103. Based on the master clock, the controller 103 generates and outputs the master clock or a clock obtained by dividing the master clock. The vertical scanning circuit 101, the signal converter 106, and the horizontal scanning circuit 107 are controlled in synchronization with the clock output of the controller 103. The controller 103 is connected to the memory 109 and performs control according to the data stored in the memory 109.

[0066] The vertical scanning circuit 101 sets the address and drives the emission signal line to perform vertical scanning. The emission signal line is arranged along the x-axis, and each emission signal line provides an emission signal to multiple OLEDs. The signal converter 106 performs a signal conversion process, for example, converting the analog output of the pixel into a digital output; and outputs the digital output to the output circuit 108. In addition, the horizontal scanning circuit 107 selects each signal conversion unit of the signal converter 106 in synchronization with the clock output output by the controller 103, and controls the signal converter 106 to read the signal from the signal line 105 and output the signal to the output circuit 108. The horizontal scanning circuit 107 drives the data signal line. The data signal line is arranged along the y-axis and provides a data signal to make each of the multiple OLEDs emit, and the multiple OLEDs are multiple emission signal elements. In one embodiment, the signal converter 106 may include an analog front end (Analog Front End, AFE). AFE is a photometric device and is used as a detection unit, and the detection unit detects the reflected light of the subject emitted by the OLED through the PD.

[0067] According to the present embodiment, the pixel circuit composed of the combination of OLED and APS can be applied to various electronic devices such as, but not limited to, cellular phones, smart phones, personal digital assistants (PDA), and PCs.

[0068] Figure 2 An example of a configuration of a pixel circuit for an OLED is shown. The pixel circuit is configured as a 7T1C+1T+PD circuit and includes a pixel unit driving circuit 2 and a PD driving circuit 3.

[0069] In the pixel array 104, each row includes a plurality of pixel units. The pixel unit driving circuit 2 drives and controls the pixel of each pixel unit in the nth row, and 1 sub-pixel corresponds to the pixel unit in the following description. The pixel unit driving circuit 2 includes 1 OLED, 7 transistors and 1 capacitor. 1 OLED corresponds to a sub-pixel of one color of red (R), green (G) and blue (B) constituting 1 pixel.

[0070] The pixel unit driving circuit 2 includes a switching transistor T2 for switching a data write signal, which is a data signal applied to a corresponding data line in response to a write signal, and the data write signal is a scan signal applied to the nth write line. The pixel unit driving circuit 2 also includes a driving transistor T4 and a compensation transistor T3. The driving transistor T4 provides a charging voltage corresponding to the data signal input to the capacitor C1 via the switching transistor T2 at the gate, and provides a driving current for the organic EL element. The compensation transistor T3 compensates for the threshold voltage of the driving transistor T4. The pixel unit driving circuit 2 also includes a capacitor C1 and an organic EL element OLED. The capacitor C1 is used to store a data signal having a voltage level applied to the gate of the driving transistor T4, and the organic EL element OLED emits light corresponding to the applied driving current.

[0071] The pixel unit driving circuit 2 also includes a switching transistor T6 and a switching transistor T5. The switching transistor T6 provides a power supply voltage ELVDD to the driving transistor T4 in response to the emission signal Em, and the switching transistor T5 provides a driving current from the driving transistor T4 to the OLED in response to the emission signal Em. The pixel unit driving circuit 2 also includes a reset transistor T1. The reset transistor T1 initializes the data signal stored in the capacitor C1 in response to the Init signal, and the Init signal is a scanning signal as the (n-1)th line. In addition, the pixel unit driving circuit 2 includes a reset transistor T7. The reset transistor T7 has a source connected to a line of the initialization voltage VINI, a gate connected to a line of a write signal, and a drain connected to the OLED. Transistors T1 to T7 are configured as p-type thin film transistors (thin film transistors, TFTs).

[0072] The switch transistor T2 has a gate, a source and a drain. The gate is applied with a write signal to be applied to the corresponding scan line, the source is applied with a data write signal (ie, data signal) to be applied to the corresponding data line, and the drain is connected to the source of the driving transistor T4.

[0073] The driving transistor T4 has a gate and a drain. The gate is connected to one terminal of the capacitor C1, and the drain is connected to one terminal of the OLED via the switching transistor T5. The compensation transistor T3 has a gate, a drain and a gate. The gate and the drain are respectively connected to the gate and the drain of the driving transistor T4, and the gate is applied with a write signal. The high-level power supply voltage ELVDD is supplied from the corresponding power supply to the other terminal of the capacitor C1.

[0074] The switching transistor T5 has a gate, a source and a drain. The gate is applied with an emission signal Em, the source is connected to the drain of the driving transistor T4, and the drain is connected to one end of the OLED. The other end of the OLED is connected to a power supply of a voltage ELVSS.

[0075] The PD driving circuit 3 includes a photodiode PD (i.e., a light receiving element) and a transistor T8. In the PD, a PN junction is composed of a p-type semiconductor layer on the light receiving side and an n-type semiconductor layer on the substrate side. When a reverse bias is applied to the PN junction, the PN junction with almost no carrier becomes a depletion layer. When light with energy greater than the bandgap width of the semiconductor is irradiated near the depletion layer, a carrier is generated. The PD can generally be configured as a PIN photodiode. The PIN photodiode includes three layers, namely, a p-type semiconductor layer and a n-type semiconductor layer. + -Si, i-Si and n-Si + -Si, and an electrode disposed between the layer structures. In the case of a PIN photodiode, the presence of the i-Si layer widens the width of the depletion layer obtained when a reverse bias is applied, thereby ensuring the use of a photodiode with a high reverse bias voltage. The high reverse bias voltage in the wide depletion layer quickly moves the carrier, increasing the response speed.

[0076] The transistor T8 has a gate, a source and a drain. The gate is connected to a sensing signal (i.e., a scanning signal for reading data), the source is connected to the anode of the PD, and the drain is connected to the read line data sense (Data Sense). The transistor T8 is configured as a p-type thin film transistor (TFT).

[0077] Next, refer to Figure 3 Example description of the timing diagram in Figure 2 The operation of the 7T1C+1T+PD circuit is shown.

[0078] Assume that the 7T1C+1T+PD circuit is driven by the (n-1)th scan signal Init1, the nth scan signal Init2 (i.e., Write1), the emission signal Em1, and the switch signal Sense1. The period from time t1 to time t2 is an initialization period in which the scan signal Init1 is low, and the scan signal Write1, the emission signal Em1, and the switch signal Sense1 are high.

[0079] The reset transistor T1 is turned on by the scan signal Init1, and the other transistors T2 to T7 are turned off by the high-level scan signal Write1 and the emission signal Em1. Therefore, the data signal stored in the capacitor C1 is initialized, and the gate voltage of the driving transistor T4 is initialized.

[0080] Next, during the pre-charging period from t3 to t4, the scan signal Init1 is high, the scan signal Write1 is low, and the emission signal Em1 and the switch signal Sense1 are high. The reset transistor T1 is turned off, the compensation transistor T3 and the switch transistor T2 are turned on by the low-level scan signal Write1, and the switch transistors T5 and T6 are turned off by the emission signal Em1. Therefore, the voltage level of the data write signal, that is, the data signal applied to the corresponding data line, is applied to the source of the drive transistor T4, so that the gate voltage of the drive transistor T4 is stabilized to the voltage Vdata of the data write signal plus the threshold voltage Vth of the drive transistor T4 through the compensation transistor T3, and is stored in the capacitor C1 that completes the pre-charging operation.

[0081] The period including and after t4 is an emission period in which the scanning signal Init1 is at a high level, and after the scanning signal Write1 becomes high, the emission signal Em1 becomes low. The switching transistors T5 and T6 are turned on by the low-level emission signal Em1, the reset transistor T1 is turned off by the high-level scanning signal Init1, and the compensation transistor T3 and the switching transistor T2 are turned off by the high-level scanning signal Write1. Therefore, ELVDD is applied to the source of the driving transistor T4, and the gate-source voltage Vgs of the driving transistor T4 becomes Vgs=Vdata+Vth-ELVDD, and the current I flowing through the OLED is

[0082] I=k·(Vgs-Vth) 2

[0083] =k(Vdata+Vth-ELVDD-Vth) 2

[0084] =k(Vdata-ELVDD) 2

[0085] A current that is independent of the threshold voltage is caused to flow through the OLED, thereby emitting light.

[0086] In the read cycle from t5 to t6, the scan signals Init1 and Write1 are at high level, and Em1 and Sense1 are at low level. Therefore, the transistor T8 is turned on, so that the signal from the PD is read out by the read line Data Sense.

[0087] In the case of an 8×8 pixel frame, the above process is performed on 8 lines. Therefore, 8 scan signals Write1 to Write8 (ie, Init2 to Init9), 8 emission signals Em1 to Em8, and 8 switch signals Sense1 to Sense8 are applied to the PDs of 8 lines.

[0088] The combination of the above-mentioned OLED and PD has two problems, namely, a reduction in the signal-to-noise ratio and blurring. These problems are described below.

[0089] First, the reduction in signal-to-noise ratio is described. The integration of the 7T1C+1T+PD circuit is lower than that of the 7T1C+APS circuit, and the corresponding reduction in resolution is also alleviated. However, since the 7T1C+1T+PD circuit has no amplifier transistor, the signal-to-noise ratio is reduced. For example, when authentication (e.g., fingerprint authentication) is performed based on a captured image, very small differences in reflected light from an object must be detected for each frame, which requires a higher signal-to-noise ratio. When the signal-to-noise ratio is low, a full-noise fingerprint image is given, which has an adverse effect on authentication.

[0090] In the method of improving the signal-to-noise ratio, it is known to apply the CDM driving method to the image sensor driving method. Since the CDM driving method opens multiple gate lines at the same time, a large amount of data should be collected at the same time. This makes the circuit configuration of the CDM drive complicated. In this regard, the CDM driving method in the present embodiment is implemented with a simple configuration.

[0091] The blur problem is described below. In the case of a display including an image sensor, it is necessary to install an optical device for the image sensor. The optical device for the image sensor is provided on a pixel unit included in the display. In the case where the optical device is a lens, for example, a microlens for collecting more light on a light receiving element is provided on the pixel unit, and a focusing lens is provided on the microlens. However, for the display, in order to ensure a wide viewing angle, it is necessary to diffuse the light. Since the optical device of the image sensor has an adverse effect on the diffusion of light, the quality of the acquired display image is reduced, resulting in blur.

[0092] As a method of eliminating blur, a lens-less camera technology is known in which a lattice of a coding mask is set on the surface of an image sensor without using a focusing lens. Light reflected from a subject passes through the lattice to reach the image sensor in slightly different combinations. The image captured by the image sensor becomes an image of the subject after synthesis and analysis. However, a coding mask should be prepared with a complex pattern. In addition, it is difficult to prepare a coding mask that does not reduce display quality.

[0093] In order to improve blur, the present embodiment uses pattern lighting technology. Specifically, in order to avoid crosstalk of received light, patterned light that changes with time is output from the display, and light reflected from the subject is detected.

[0094] Next, refer to Figures 4 to 6 Describe pattern lighting techniques.

[0095] Figure 4 FIG. 1 is a perspective view of a combination of a display and an image sensor. Figure 4As shown, when the image sensor is mounted on a display, the Figure 4 The display 1102 shown in (a) covers Figure 4 (b) shows the structure on the image sensor 1104. Figure 5 FIG. 1 is a diagram showing the relationship between the combined array of OLED and PD in the display device and the subject. Figure 5 As shown, the image sensor 1104 has an array of PDs 1204, and the display 1102 includes an array of OLEDs 1202. For example, when light is emitted from a column of red (R) sub-pixels according to the light patterned on the display 1102, the red light hits the subject 1203, as shown in FIG. Figure 5 As shown in (a). The light reflected from the subject 1203 is diffused and hits each of the plurality of PDs 1204. The light emitted from the OLED 1202 is reflected in different directions according to the position on the subject 1203, and one PD 1204 receives the light reflected from different positions. In this way, the PD 1204 detects the subject 1203 based on the light from the OLED 1202.

[0096] like Figure 4 As shown, the light array 1106 perpendicular to the x-axis is an example of patterned light, and various patterns can be applied to the patterned light. For example, for patterned light, a light array horizontal to the x-axis, a grid pattern of a light array, a plurality of columns having a predetermined angle to the x-axis, a dot grid pattern, and a checkerboard pattern can all be used.

[0097] In patterned lighting, the patterned light array 1106 varies over time. Figure 6 Shows Figure 4 The example of patterned light moving in the horizontal direction (i.e., the x-axis direction) is shown. Figure 6 In the example shown, the OLED 1202 located directly below the subject 1203 emits light, and the reflected light of the subject 1203 is greater than that of the subject 1203. Figure 5 Therefore, the PD 1204 near the OLED 1202 located directly below the subject 1203 receives stronger reflected light. Therefore, according to the intensity of reflected light received by each PD, the shape of the subject 1203 can be obtained by the AFE connected to the PD.

[0098] Figure 7 An example of a frame pattern for pattern illumination is shown. A frame pattern is a pattern image displayed in an object sensing area in which an object approaching the display surface of the display device is detected. The size of the frame pattern is designed according to the object to be detected. Figure 7Each frame pattern shown in is a frame of 8×8 pixels, the white part represents the pixels that emit light, and the gray part represents the pixels that do not emit light. In the example shown in the figure, 8 types of frame patterns are prepared, wherein one frame consists of six emitting pixels. These frame patterns are stored in the memory 109 of the display device 100. The controller 103 reads out from the memory 109 in sequence and uses a single frame pattern to control the light emission of the pixel.

[0099] However, in pattern lighting, in order to reduce crosstalk, it is necessary to prepare a complex frame pattern or various frame patterns. In this regard, in this embodiment, the reduction of crosstalk is achieved with fewer frame patterns.

[0100] Figure 8 Figure 1 is an example of pixel driving in fingerprint authentication. Figure 8 , a frame pattern consisting of a non-luminous portion 1902 shown in gray and a luminous portion 1904 shown in white is displayed on the display 1901. The emission signal line for controlling the emission of the display 1901 extends along the x-axis, and the data signal line through which the data signal flows extends along the y-axis. In the case of using the frame mode, all emission signal lines are enabled to let the emission signal flow, so that the emission of the pixels of the portion 1904 that emits light is controlled by the data signal from the data signal line. The user places a finger on the luminous portion 1904 for the authentication process.

[0101] Next, we will refer to Fig. 9 Describe the principles of fingerprint authentication. Fig. 9 9 shows a cross-sectional structure of a display, wherein a finger 901 is placed on a display surface 902 and drive control is performed along a time axis t. Fig. 9 In (a), PD a1 is connected to AFE at the beginning. Seven OLEDs a2 to g2 all emit light, and PD a1 receives light reflected from finger 901 and transmits a current corresponding to the intensity of the light to AFE.

[0102] Next, in Fig. 9 In (b), PD b1 is connected to AFE. Seven OLEDs a2 to g2 all emit light, PD b1 receives light reflected from finger 901, and transmits a current corresponding to the intensity of the light to AFE. Similarly, the PDs connected to AFE move in sequence, and the light intensity is measured based on the current flowing from each PD in AFE. Similarly, the PDs connected to AFE are moved in sequence, and the light intensity is measured based on the current flowing from each PD in AFE. Fig. 9 The above-mentioned processing is performed on the OLED and PD arranged in the direction of the thin plate surface.

[0103] Fig.10 For virtual display Fig. 91 is a graph showing the intensity of light received by PD a1 to PD g1, where the horizontal axis represents the position of the OLED. For example, PD a1 receives strong reflected light based on OLED a2, then receives strong reflected light based on OLED b2, but hardly receives reflected light based on OLEDs c2 to g2. In addition, considering the relationship with finger 901, the light received by the PD located directly below the fingerprint valley is weaker than the light received by the PD located directly below the fingerprint ridge. Since the intensity of light received by each PD is the sum of the reflected light from all OLEDs, it can be understood that the reference Fig.10 (a), the light received by PD d1 is weak. Fig.10 (b) is a curve 1002 plotting the intensity of light received by the PD. Here, the horizontal axis represents the relative position of the PD. Fig.10 (b), when there is no valley, the value of the measurement result of the valley part is lower than the curve 1001 of the measurement result. Therefore, it can be understood that there is a valley near PD d1. However, the relative difference between the measurement values ​​of the fingerprint ridge and the fingerprint valley is 0.1, indicating that the signal-to-noise ratio is low, resulting in blur.

[0104] Next, refer to Fig.11 , taking fingerprint authentication as an example, the method of driving a display device according to this embodiment is described. Fig.11 A cross-sectional structure of a display is shown, wherein a finger 901 is placed on a display surface 902 and drive control is performed along a time axis t. Fig.11 The drive control shown adopts the CDM drive method and Fig.11 In all states shown in (a) of FIG11 and (b) of FIG11 , all PDs a1 to g1 are connected to the AFE. Fig.11 In (a), all OLEDs except OLED a2 emit light, and the light received by all PDs is measured by the AFE. Fig.11 In (b), all OLEDs except OLED b2 emit light, and the light received by all PDs is measured by the AFE. Similarly, to prohibit the emission of OLEDs, the emission of OLED g2 is sequentially moved in the y-axis direction. Fig.11 The light received by all PDs is measured by the AFE. Fig.11 The above process is performed for those OLEDs and PDs arranged in the direction of the thin plate surface. In this way, the movement process of the emission stop of the OLEDs arranged along the emission signal line is realized, which is realized along the y-axis.

[0105] Next, the CDM driving method is described in detail. Fig.11 In FIG. 1 , the voltages associated with the outputs of PDs a1, b1, ..., g1 are represented as Va1, Vb1, ..., Vg1. In addition, Fig.11 (a) Fig.11 (b) ... and Fig.11 (g), the voltage measured by the AFE is represented as Va, Vb, ..., Vg. The voltage output to the AFE is the sum of the voltage Va1 associated with the output of PD a1 and the voltage Vg1 associated with the output of PD g1. Fig.11 In the case of (a), the voltage Va1 related to the output of the PD a1 located directly below the non-luminous OLED a2 is 0. Therefore, the voltage Va can be expressed as Va=Vb1+Vc1+Vd1+Ve1+Vf1+Vg1.

[0106] exist Fig.11 When the second OLED b2 on the left side of (b) does not emit light, the voltage Vb1 of the PD b1 located directly below the OLED b2 is 0. Therefore, the voltage Vb output to the AFE can be expressed as Vb=Va1+Vc1+Vd1+Ve1+Vf1+Vg1. Similarly, when measuring the voltages c to g output to the AFE by sequentially moving the non-emitting OLEDs, the voltages Va to Vg measured by the AFE can be expressed by the following determinant.

[0107]

[0108] In the above determinant, the following matrix is ​​called "CDM code".

[0109]

[0110] To obtain output voltages Va1 to Vg1 from each PD, the inverse matrix should be applied to [Va, Vb, Vc, Vd, Ve, Vf, Vg] as shown below.

[0111]

[0112] The intensity of light received by each PD can be obtained in this way.

[0113] Fig.12 for Fig.11 The intensity of light received by the PD in FIG1003. The relative difference between the measured values ​​of the fingerprint ridges and the fingerprint valleys is 0.5, indicating a significant improvement in signal-to-noise ratio and blur.

[0114] Fig.13 The frame pattern used in the pattern illumination provided by this embodiment is shown. The size of the frame pattern is designed according to the object to be detected. Fig.13Each of the first frame mode and the second frame mode shown is a frame of 8×8 pixels, the white portion represents the pixels that emit light, and the gray portion represents the pixels that do not emit light. In the example shown in the figure, a frame mode in which one frame consists of 8 pixels is prepared. These frame modes are stored in the memory 109 of the display device 100, and the controller 103 sequentially uses each frame mode in the memory 109 to control the emission of the pixels. In this embodiment, the emission of the OLED is controlled using these two types of frame modes to generate a similar Figure 7 Patterns of 8 types of frame modes are shown.

[0115] Fig.14 A diagram of an example of pixel driving in fingerprint authentication provided for the present embodiment. The display 1401 displays a frame mode including non-luminous portions 2102 and 2014 shown in gray and a luminous portion 2016 shown in white. The frame mode displayed on the display 1401 changes along the time axis t. The emission signal line for controlling the emission of the display 1401 extends along the x-axis, and the data signal line through which the data signal flows extends along the y-axis. In the case of using the frame mode, all emission signal lines are enabled to let the emission signal flow, so that the emission of the pixel of the portion 2106 that emits light is controlled by the data signal from the data signal line. The user places a finger on the luminous portion 2106 for the authentication process.

[0116] Fig.15 A diagram of an example of pixel driving in fingerprint authentication provided for another embodiment. In the case of using the frame mode, only the emission signal line of the portion 2104 having the light emitting portion 2106 is enabled to let the emission signal flow, so that the emission of the pixel of the portion 2106 emitting light is controlled according to the data signal from the data signal line. The user places a finger on the light emitting portion 2106 for the authentication process. In this case, other emission signal lines are disabled so that waste of power consumption can be avoided.

[0117] Fig.16 Shows Fig.15Time variation of the frame image displayed on the display device in the illustrated embodiment. In the photodiode drive process according to the present embodiment, a first frame mode having 8 subframes is displayed, and scanning is performed in the 4×4 pixel portion shown by the solid line 1501. In the display process of the first subframe to the fourth subframe, the first frame mode is displayed, and the first subframe is formed by disabling the third emission signal line from the top of the figure. Next, the second subframe is formed by disabling the fourth emission signal line from the top of the figure. Similarly, the third subframe and the fourth subframe are formed by sequentially moving the emission signal lines to be disabled. Next, the second frame mode is displayed, and the fifth subframe is formed by disabling the third emission signal line from the top of the figure. Then, the sixth subframe is formed by disabling the fourth emission signal line from the top of the figure. Similarly, the seventh subframe and the eighth subframe are formed by sequentially moving the emission signal lines to be disabled.

[0118] According to the above embodiments, by combining the CDM driving method with pattern illumination, the signal-to-noise ratio can be increased and blur can be reduced. In addition, the combination of the CDM driving method with pattern illumination can simplify driving control.

[0119] The above-described embodiments can be applied to a configuration in which the PD circuit has an amplifier transistor and a configuration in which the PD circuit does not have an amplifier transistor to demonstrate the same effect.

[0120] (Second embodiment)

[0121] The second embodiment of the present invention is described below. In this embodiment, at least two adjacent emission signal lines are enabled at the same time. Then, the disabled emission signal lines are moved sequentially over time. For example, in an array consisting of 9 OLEDs and 9 PDs, when drive control is performed to disable two adjacent emission signal lines, the CDM code for representing the voltage output to the AFE can be expressed as follows:

[0122]

[0123] In the CDM driving method according to the present embodiment, as described in the first embodiment, the voltage output to the AFE is measured 9 times while sequentially moving the two PDs that stop transmitting to obtain the measured voltages Va, Vb, Vc, Vd, Ve, Vf, Vg, Vh, and Vi. By applying the inverse matrix of the above CDM code to [Va, Vb, Vc, Vd, Ve, Vf, Vg, Vh, Vi], the voltage of each of the 9 PDs can be obtained.

[0124] (Third Embodiment)

[0125] The third embodiment of the present invention is described below. In this embodiment, by using a frame mode to flow the emission signal, only the emission signal line including the light-emitting part is enabled, and the emission control of the pixel part that emits light is controlled according to the data signal of the data signal line. At the same time, other emission signal lines are disabled. At this time, power consumption can be further reduced by disabling the sensing signal line for reading data.

[0126] Fig.17 An example of a timing diagram when performing drive control for disabling an emission signal line in an array consisting of 9 OLEDs and 9 PDs is shown. When fingerprint authentication is performed on the first to ninth emission signal lines, only the emission signals Em1 to Em9 are turned on or off, and the emission signals Em10 to EmN of the tenth and subsequent emission signal lines are all disabled. As for the sense signal as a scanning signal for reading data, only the first to ninth signals Sense1 to Sense9 are enabled or disabled, and the emission signals Sense10 to SenseN of the tenth and subsequent emission signal lines are all disabled.

[0127] The gate driver circuit according to this embodiment can adopt a gate driver on array (GOA). GOA adopts a driving method in which the gate driver circuit is directly integrated on the array substrate without external connection and realizes the row-by-row scanning of the gate. GOA technology can improve the integration, thereby shortening the manufacturing process and increasing the product cost. Fig.18 A configuration example of the GOA of a display device is shown. In the GOA, an emission scanning GOA and a gate scanning GOA are arranged in the middle of an active area included in a pixel array. The emission scanning GOA is a GOA that drives an emission signal. The gate scanning GOA is a GOA that drives a scanning signal (an Init signal, a write signal, and a detection signal as a scanning signal for reading data). The emission scanning GOA is connected to the odd-numbered lines on the active area and drives the emission signal lines in sequence. The gate scanning GOA is connected to the even-numbered lines on the active area and drives the sensing signal lines in sequence. In the present embodiment, only the emission signal lines of the part used for fingerprint authentication are scanned, and for the scanning signal lines, only the emission signal lines of the components used for fingerprint authentication are scanned.

[0128] Fig.19 FIG. 1 is a diagram showing another configuration example of a gate drive circuit. Fig.19 As shown, the GOA driving circuit can be composed of multiple emission scanning GOAs and multiple gate scanning GOAs. In this case, the driving control is performed so that only the emission scanning GOA connected to the emission signal line of the component for fingerprint authentication and the gate scanning GOA connected to the scanning signal line are scanned. During the verification process, other GOAs are always disabled. In this way, the power consumption in the authentication process can be reduced.

[0129] (Fourth embodiment)

[0130] Next, a fourth embodiment of the present invention is described. Figure 2 In the above-mentioned embodiment shown, there is a transistor T8, which is connected between the PD and the read line data sense (Data Sense) when reading data. Then, the scan of data reading is performed by applying the sense signal as a scan signal to the gate of T8. However, in the case of the CDM driving method, all PDs are connected to the AFE along the vertical direction of the display in one data reading from the PD. This does not require scanning along the vertical direction of the display. Therefore, in this embodiment, the transistor T8 is removed, and the driving control is performed so that all PDs are connected to the AFE simultaneously along the vertical direction of the display. Fig. 20 In the 7T1C+PD circuit shown, a switch 2001 is provided between the anode of the PD and the AFE. The switch 2001 is controlled by a switch signal so that the anode is connected to ELVDD when fingerprint detection is not performed, and the anode is connected to the AFE when fingerprint detection is performed. Other PDs along the vertical direction of the display are similarly controlled by a switch signal. Removing one TFT from the 7T1C+1T+PD circuit in this way can provide a simpler configuration.

[0131] Fig.21 An example of a timing diagram when an emission signal line is driven and controlled in an array consisting of 9 OLEDs and 9 PDs is shown. A switching signal for switching the switch 2001 may be controlled so as to periodically connect the PD to the power supply voltage ELVDD or AFE.

[0132] (Fifth Embodiment)

[0133] Next, a fifth embodiment of the combined pattern illumination and mask of the present invention will be described. Fig. 22 FIG. 1 is a diagram showing the relationship between the combined array of OLED and PD in a display device and the subject. Fig. 22 In the embodiment, OLED 1202 and PD 1204 are arranged alternately. Fig. 22 In (a), the mask 1206 of the image sensor is set on the PD 1204. The mask 1206 blocks the optical path of a portion of the reflected light from the subject. Fig. 22 In (b), the dotted arrows indicate light that is blocked by the mask and does not reach PD 1204. The effect of reducing crosstalk with a complex mask can be achieved by Figure 4 or Figure 5 The horizontal direction in the image can be improved by moving a row of OLEDs that emit light in this way. In addition, the image can be easily reconstructed.

[0134] Fig.23The top view of the PD arrangement in the image sensor shows the positional relationship between the PD and the mask. Fig.23 , describes an example of a mask. The mask shown by black dots or black lines can be configured as Fig.23 The plurality of vertical linear masks shown in (a) may be configured as Fig.23 In addition, the mask may be a vertical linear mask arranged at different positions on the PDs in each PD column, such as Fig.23 In addition, the mask can be set at different positions on each PD, such as Fig.23 as shown in (d).

[0135] In another example, a collimator or pinhole may be used on the image sensor instead of a lens to reduce blur in the image sensor and display combination.

[0136] In the above embodiment, the pixel unit driving circuit is exemplarily composed of 7 transistors and 1 capacitor. However, no matter which example is used, the number of transistors and capacitors and the circuit configuration can be changed in use.

[0137] In summary, the above are merely examples of embodiments of the technical solution of the present application and are not intended to limit the protection scope of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application are included in the protection scope of the present application.

Claims

1. A method for driving a display device, characterized in that: The display device comprises: a plurality of transmission signal lines, which are arranged along a first axis and respectively provide transmission signals to a plurality of light-emitting elements; a plurality of data signal lines, which are arranged along a second axis and provide data signals so that each of the plurality of light-emitting elements emits light; a storage unit, which stores a plurality of frame modes, each of which is a pattern image displayed in an object sensing area; a light receiving element, which detects an object according to light from the light-emitting element, wherein the plurality of frame modes are designed according to the object, and the first axis and the second axis are perpendicular. The method comprises: for each of the plurality of frame modes, Scanning a mode image, wherein the scanning comprises: In a display frame mode, stopping emission of light-emitting elements arranged along a portion of the emission signal lines; In the frame mode of the display, moving the transmission signal line to be prohibited from transmitting along the second axis; The signal converter measures the reflected light from the object based on the emitted light of the light emitting element through the light receiving element.

2. The method according to claim 1, characterized in that The scanning includes scanning the pattern image only by light emitting elements within the object sensing area.

3. The method according to claim 2, characterized in that The stopping of the emission of the light emitting elements arranged along a portion of the transmission signal line includes prohibiting the light emitting elements outside the object sensing area from emitting light.

4. The method according to claim 1, characterized in that: The reading of the light receiving element is controlled according to the reading signal of the scanning signal line, and the stopping of the emission of the light emitting element arranged along a part of the emission signal line includes prohibiting the activation of the scanning signal line outside the object sensing area.

5. The method according to claim 1, characterized in that The stopping of the emission of the light emitting elements arranged along a portion of the emission signal lines includes simultaneously prohibiting the emission of the light emitting elements in the pattern images arranged along at least two adjacent emission signal lines.

6. The method according to claim 1, characterized in that The light receiving elements are connected to a switch, and a controller controls the switch so that the plurality of light receiving elements connected to one data signal line are simultaneously connected to the signal converter.

7. A display device, characterized in that: include: A plurality of transmission signal lines are arranged along the first axis and respectively provide transmission signals to the plurality of light emitting elements; a plurality of data signal lines arranged along a second axis and providing a data signal to enable each of the plurality of light emitting elements to emit light, wherein the first axis is perpendicular to the second axis; A storage unit storing a plurality of frame modes, each of the frame modes being a pattern image displayed in a sensing area of ​​the object, wherein the plurality of frame modes are designed according to the object; a light receiving element for detecting the object based on the light from the light emitting element; A controller controls a display to display each frame mode of the plurality of frame modes, wherein displaying each frame mode of the plurality of frame modes comprises: In a display frame mode, stopping emission of light-emitting elements arranged along a portion of the emission signal lines; In the frame mode of the display, moving the transmission signal line to be prohibited from transmitting along the second axis; A signal converter measures the reflected light from the object based on the emitted light of the light emitting element.

8. The display device according to claim 7, characterized in that The controller scans the pattern image only through the light emitting elements within the object sensing area.

9. The display device according to claim 8, characterized in that The controller prohibits the light emitting elements outside the object sensing area from emitting light.

10. The display device according to claim 9, characterized in that The controller includes a plurality of gate on array (GOA) circuit substrates, and only enables the GOA that drives the light emitting elements within the object sensing area.

11. The display device according to claim 7, characterized in that The light receiving element is read according to a read signal of a scanning signal line, and the controller prohibits enabling the scanning signal line outside the object sensing area.

12. The display device according to claim 7, characterized in that The controller simultaneously inhibits emission of the light emitting elements in pattern images arranged along at least two adjacent emission signal lines.

13. The display device according to claim 7, characterized in that The light receiving elements are connected to a switch, and the controller controls the switch so that the plurality of light receiving elements connected to one data signal line are simultaneously connected to the signal converter.

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