Display device

Abstract

The invention provides a display device which comprises a plurality of pixel units, and each pixel unit comprises a driving transistor, a first light-emitting device, a second light-emitting device, a first transistor resistor and a second transistor resistor. The anode of the first light-emitting device is electrically connected with the first end of the first transistor resistor, the anode of the second light-emitting device is electrically connected with the first end of the second transistor resistor, and the cathode of the first light-emitting device is electrically connected with the cathode of the second light-emitting device. The second end of the first transistor resistor and the second end of the second transistor resistor are electrically connected with the source electrode or the drain electrode of the driving transistor. The display device can enable the other light-emitting device to continuously emit light when one of the light-emitting devices generates cathode and anode short circuit, so that the dark spot problem is improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display device. Background Art

[0002] The dark spot problem of OLED (Organic Light-Emitting Diode) display devices is one of the main factors affecting the yield of OLED display devices.

[0003] The dark spot problem is mainly caused by the short circuit between the cathode and the anode of the OLED device. The reasons for the short circuit between the cathode and the anode include: the presence of foreign particles in the anode metal layer, the presence of foreign particles in the organic light-emitting layer, and the migration of silver (Ag) atoms in the anode metal layer. At present, foreign particles are usually reduced by improving the cleanliness inside the production workshop and production equipment, and the migration of silver atoms is suppressed by controlling the temperature and processing time of the high-temperature process after the formation of the anode metal layer. However, these control measures have many difficulties in the actual implementation process, and it is difficult to completely avoid the occurrence of anode and cathode short circuits.

[0004] Therefore, it is necessary to propose a new technical solution to solve the above technical problems. Summary of the invention

[0005] An embodiment of the present application provides a display device, aiming to improve the dark spot problem of an OLED display device.

[0006] An embodiment of the present application provides a display device, comprising: a plurality of pixel units, each of which is provided with a pixel circuit, and the pixel circuit comprises: a driving transistor; a first light-emitting device; a second light-emitting device; a first transistor resistor; and a second transistor resistor; wherein the anode of the first light-emitting device is electrically connected to the first end of the first transistor resistor, the anode of the second light-emitting device is electrically connected to the first end of the second transistor resistor, the cathode of the first light-emitting device is electrically connected to the cathode of the second light-emitting device, and the second end of the first transistor resistor and the second end of the second transistor resistor are both electrically connected to one of the source and the drain of the driving transistor.

[0007] In the above display device, a ratio of the resistance value of the first transistor resistor to the resistance value of the first light emitting device and a ratio of the resistance value of the second transistor resistor to the resistance value of the second light emitting device are both in the range of 0.5 to 2.

[0008] In the above display device, the first transistor resistor and the second transistor resistor are both N-type thin film transistors; the gate-drain voltage of the first transistor resistor is less than the threshold voltage of the first transistor resistor; the gate-drain voltage of the second transistor resistor is less than the threshold voltage of the second transistor resistor.

[0009] In the above display device, the threshold voltages of the first transistor resistor and the second transistor resistor are greater than 0V.

[0010] In the above display device, the ratio of the resistance value of the first transistor resistor to the resistance value of the first light-emitting device is in the range of 0.8 to 1.2; the ratio of the resistance value of the second transistor resistor to the resistance value of the second light-emitting device is in the range of 0.8 to 1.2.

[0011] In the above display device, the resistance values ​​of the first transistor resistor and the second transistor resistor are greater than 10 6 ohms and less than 10 8 ohms.

[0012] In the above-mentioned display device, the drain of the first transistor resistor is electrically connected to one of the source and the drain of the driving transistor, and the gate of the first transistor resistor is electrically connected to the drain of the first transistor resistor; the drain of the second transistor resistor is electrically connected to one of the source and the drain of the driving transistor, and the gate of the second transistor resistor is electrically connected to the drain of the second transistor resistor.

[0013] In the above display device, a ratio of the light emitting brightness of the first light emitting device to the light emitting brightness of the second light emitting device is in a range of 0.9 to 1.1.

[0014] In the above display device, cathodes of the first light emitting device and the second light emitting device are electrically connected to a reference potential terminal.

[0015] In the above-mentioned display device, the brightness of the pixel unit in which the cathode and anode of the first light-emitting device are short-circuited is lower than the brightness of the pixel unit in which neither the cathode and anode of the first light-emitting device nor the cathode and anode of the second light-emitting device are short-circuited, and the brightness of the pixel unit in which the cathode and anode of the first light-emitting device are short-circuited is higher than one-fourth of the brightness of the pixel unit in which neither the cathode and anode of the first light-emitting device nor the cathode and anode of the second light-emitting device are short-circuited.

[0016] In the display device provided in the embodiment of the present application, each pixel unit includes two light-emitting devices, and each light-emitting device is electrically connected to a driving transistor through a transistor resistor. Since the resistance value of the transistor resistor is similar to the resistance value of the light-emitting device, when the cathode and anode of one of the light-emitting devices are short-circuited, the current of the short-circuited branch will not be significantly greater than the current of the non-short-circuited branch, so that the light-emitting device that is not short-circuited can continue to emit light. This design does not require manual positioning of the dark spot position and laser repair, and can automatically improve the dark spot problem, saving human resources and equipment resources consumed by using laser cutting to cut the circuit at the anode of the pixel unit where the cathode and anode are short-circuited, thereby improving production efficiency and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a display device provided in an embodiment of the present application.

[0018] Figure 2 is a circuit diagram of a pixel unit of a display device provided in an embodiment of the present application.

[0019] Figure 3 yes Figure 2 The schematic diagram of the pixel unit shown is when it emits light normally.

[0020] Figure 4 yes Figure 2 The schematic diagram of the pixel unit shown is when the cathode and anode are short-circuited. DETAILED DESCRIPTION

[0021] The specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0022] The terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different technical features. The term "plurality" and similar words mean two or more, unless otherwise clearly defined.

[0023] The embodiments of the present application may be combined with each other.

[0024] The driving circuit of the pixel unit of the OLED display device in the prior art includes three transistors and one capacitor (3T1C structure). When the cathode and anode of the light-emitting device in the pixel unit are short-circuited, there is no voltage difference between the cathode and the anode, resulting in the pixel unit being unable to emit light, forming a dark spot.

[0025] In order to solve the above technical problems, the display device provided in the present application includes a plurality of pixel units. Figure 2 , Figure 3 and Figure 4As shown, each pixel unit includes: a driving transistor T1, a switching transistor T2, a storage capacitor Cst, a first light emitting device OLED1, a second light emitting device OLED2, a first transistor resistor R1 and a second transistor resistor R2.

[0026] The anode of the first light emitting device OLED1 is electrically connected to the first end of the first transistor resistor R1, and the anode of the second light emitting device OLED2 is electrically connected to the first end of the second transistor resistor R2. The cathode of the first light emitting device OLED1 is electrically connected to the cathode of the second light emitting device OLED2. The second end of the first transistor resistor R1 and the second end of the second transistor resistor R2 are both electrically connected to the drain of the driving transistor T1.

[0027] The source of the driving transistor T1 is electrically connected to the high level signal input terminal VDD. The gate of the switching transistor T2 is electrically connected to the scan signal input terminal WR, and the source of the switching transistor T2 is electrically connected to the data signal input terminal Data. The drain of the switching transistor T2 is also electrically connected to the first plate of the storage capacitor Cst, and the second plate of the storage capacitor Cst is electrically connected to the drain of the driving transistor T1. The gate of the driving transistor T1 is electrically connected to the drain of the switching transistor T2.

[0028] The pixel unit further includes a detection transistor T3 . The gate of the detection transistor T3 is electrically connected to the detection control signal input terminal RD, the drain of the detection transistor T3 is electrically connected to the detection signal line Sense, and the source of the detection transistor T3 is electrically connected to the drain of the driving transistor T1 .

[0029] The first transistor resistor R1 and the second transistor resistor R2 are both thin film transistors with the gate and drain short-circuited. 7 Ohm), the present application uses a specially configured thin film transistor to achieve a high resistance value. Specifically, the required high resistance value is obtained by operating the thin film transistor in a saturation region.

[0030] The condition for a thin film transistor to work in the saturation region is: the drain-source voltage is greater than the gate-source voltage minus the threshold voltage. Since the gate and drain are short-circuited, the gate-drain voltage is 0 volts. Therefore, as long as the threshold voltage of the thin film transistor is greater than 0 volts, the thin film transistor can be guaranteed to work in the saturation region. On this basis, by adjusting the parameters of the thin film transistor such as the channel length, channel width or gate insulation layer thickness, its resistance value (R TFT ) and the resistance value of the light-emitting device (R OLED )similar.

[0031] like Figure 4 As shown, when the cathode and anode of the first light emitting device OLED1 are short-circuited, due to the resistance value (RTFT ) and the resistance value of the light-emitting device (R OLED ), the current will not all flow through the short-circuited first light-emitting device OLED1, and the second light-emitting device OLED2 can still obtain sufficient current to continue to emit light.

[0032] Specifically, Figure 3 and Figure 4 As shown, when the first light-emitting device OLED1 and the second light-emitting device OLED2 are both operating normally, assuming that the total current is I, since the equivalent resistances of the two branches are equal, the current of each branch is I / 2. When the cathode and anode of the first light-emitting device OLED1 are short-circuited, the current flowing through the first transistor resistor R1 is approximately twice the current flowing through the second transistor resistor R2, and the current flowing through the second light-emitting device OLED2 is approximately I / 3.

[0033] like Figure 1 As shown, the display device provided in the embodiments of the present application may be, for example, an OLED display device, a Mini-LED display device, or a Micro-LED display device. The embodiments of the present application are described using an OLED display device.

[0034] The display device includes a source driving circuit, a gate driving circuit, a timing controller, a light emitting controller, a power management chip, a substrate, a data line DATA, a scan line SCAN (WR), a power line (VDD, VSS), a light emitting control signal line EM, a pixel array, an encapsulation layer, a polarizer, a color filter, etc.

[0035] The substrate may be, for example, a glass substrate, a flexible substrate (e.g., a polyimide substrate), etc. The pixel array is composed of a plurality of pixel units PX arranged in rows and columns, and each pixel unit PX includes a light-emitting device and a driving circuit. The driving circuit includes a TFT device, which is used to control the brightness of each light-emitting device of the display device. The TFT device includes low-temperature polycrystalline silicon (LTPS) and a metal oxide TFT. The light-emitting device is electrically connected to the TFT device. The light-emitting device includes a light-emitting layer, an electron transport layer, a hole transport layer, a cathode and an anode, etc. Different organic materials can emit light of different wavelengths to achieve full-color display. The encapsulation layer includes an organic / inorganic alternating multilayer structure. Each level of the gate driving unit in the gate driving circuit corresponds to controlling a row of pixel units PX, and the gate driving unit is used to control the TFT device to achieve the gating of the pixel unit PX. Each level of the gate driving unit is mainly composed of a thin film transistor (TFT) and a capacitor. The source driving circuit is used to provide a data signal to the pixel unit PX. The timing controller is used to receive externally input image data and synchronization signals, and generate signals required by the gate driving circuit and the source driving circuit. The power management chip is used to provide the required operating voltage for each part of the display device.

[0036] In addition, the display device of the present application may also integrate an embedded touch control circuit, which is electrically connected to the display driving circuit, and implements the touch control function and the display function in a time division multiplexing manner.

[0037] like Figure 2 , Figure 3 and Figure 4 As shown, an embodiment of the present application provides a display device, which includes a plurality of pixel units, each pixel unit includes a driving transistor T1, a switching transistor T2, a storage capacitor Cst, a detection transistor T3, a first light-emitting device OLED1, a second light-emitting device OLED2, a first transistor resistor R1 and a second transistor resistor R2.

[0038] The anode of the first light-emitting device OLED1 is electrically connected to the first end of the first transistor resistor R1, the anode of the second light-emitting device OLED2 is electrically connected to the first end of the second transistor resistor R2, the cathode of the first light-emitting device OLED1 is electrically connected to the cathode of the second light-emitting device OLED2, and the second end of the first transistor resistor R1 and the second end of the second transistor resistor R2 are both electrically connected to one of the source and the drain of the driving transistor T1.

[0039] The driving transistor T1, the switching transistor T2, the detecting transistor T3, the first transistor resistor R1 and the second transistor resistor R2 are N-type thin film transistors. The other of the source and the drain of the driving transistor T1 is electrically connected to the high level signal input terminal VDD. One of the source and the drain of the switching transistor T2 is electrically connected to the data signal input terminal Data. The other of the source and the drain of the switching transistor T2 is electrically connected to the gate of the driving transistor T1. The gate of the switching transistor T2 is electrically connected to the scan signal input terminal WR. The first end of the storage capacitor Cst is electrically connected to the gate of the driving transistor T1, and the second end of the storage capacitor Cst is electrically connected to one of the source and the drain of the driving transistor T1.

[0040] The gate of the detection transistor T3 is electrically connected to the detection control signal input terminal RD, the drain is electrically connected to the detection signal line Sense, and the source is electrically connected to the drain of the driving transistor T1. The detection transistor T3 is used to monitor the working state of the driving transistor T1 in real time. When the drain voltage of the driving transistor T1 is detected to be abnormal, the detection transistor T3 will feed back the signal to the external control circuit, and the external control circuit can adjust the scan signal transmitted by the scan signal input terminal WR and the data signal transmitted by the data signal input terminal Data according to the feedback signal.

[0041] In this embodiment, the detection transistor T3 can be configured to monitor the drain voltage of the driving transistor T1 in real time, for example, the gate of the detection transistor T3 is connected to the drain point of the driving transistor T1. When the drain voltage of the driving transistor T1 exceeds a set threshold, the detection transistor T3 is turned on and transmits a signal to an external control circuit. The external control circuit is used to adjust the scanning signal WR and the data signal Data according to the detection signal to change the working state of the driving transistor T1, thereby ensuring the normal operation of the display device.

[0042] In this embodiment, the detection transistor T3 is used to detect the working state of the pixel unit. When a pixel unit is short-circuited, the detection transistor T3 is used to feed back the short-circuit signal to the external control circuit, and the external control circuit is used to make corresponding adjustments according to the short-circuit signal.

[0043] In this embodiment, the channel regions of the first transistor resistor R1 and the second transistor resistor R2 are serpentine in shape to achieve a longer equivalent channel length within a limited area. The serpentine structure of the channel region includes a plurality of straight segments and corner segments, wherein the width of the straight segment is 1 micron, the spacing between adjacent straight segments is 2 microns, and the corner segments are arc transitions to reduce stress concentration. In this way, the transistor resistors can obtain a larger equivalent channel length while maintaining a smaller occupied area.

[0044] In order to further optimize the performance of the first transistor resistor R1 and the second transistor resistor R2, the source and drain of the first transistor resistor R1 and the second transistor resistor R2 are arranged in a comb shape, the tooth width of the comb-shaped source and drain is 0.8 microns, and the tooth spacing is 1.2 microns, so that the current distribution of the first transistor resistor R1 and the second transistor resistor R2 can be more uniform. At the same time, an array of contact holes is arranged at the contact between the source and drain metal layers and the active layer, the size of the contact holes is 0.5 microns × 0.5 microns, and the contact hole spacing is 1 micron, so as to reduce the proportion of the contact resistance to the resistance value of the transistor resistance.

[0045] The resistance values ​​of the first transistor resistor R1 and the second transistor resistor R2 (R TFT ) is set by at least one of its channel length, channel width or gate insulation layer thickness.

[0046] The ratio of the channel length to the channel width of the first transistor resistor R1 and the second transistor resistor R2 is greater than 6:1.

[0047] In this embodiment, the channel length of the first transistor resistor R1 and the second transistor resistor R2 is in the range of 3-10 microns, and the channel width is in the range of 0.5-2 microns, for example, the channel length is 8 microns and the channel width is 1 micron, to obtain stable high resistance characteristics.

[0048] The resistance values ​​of the first transistor resistor R1 and the second transistor resistor R2 (R TFT ) is greater than 10 6 Ohm and less than 10 8 ohm.

[0049] In this embodiment, the resistance values ​​(R TFT ) can be calculated based on the resistance value of the light-emitting device (R OLED ) is set. For example, when the resistance value (R OLED ) is 5×10 7 Ohms, the resistance value of the first transistor resistor R1 (R TFT ) is 4.8×10 7 Ohm; when the resistance value (R OLED ) is 6×10 7 Ohms, the resistance value of the second transistor resistor R2 (R TFT ) is 5.9×10 7 ohm.

[0050] The resistance value of the first transistor resistor R1 (R TFT ) and the resistance value (R OLED ) and the resistance value of the second transistor resistor R2 (R TFT ) and the resistance value (R OLED ) are all within the range of 0.5 to 2. Preferably, the resistance value (R TFT ) and the resistance value (R OLED ) is in the range of 0.8 to 1.2. The resistance value (R TFT ) and the resistance value of the second light emitting device OLED2 (R OLED ) is in the range of 0.8 to 1.2.

[0051] The resistance value of the first transistor resistor R1 (R TFT ) and the resistance value of the second transistor resistor R2 (R TFT ) are equal or approximately equal, the resistance value (R OLED ) and the resistance value of the second light emitting device OLED2 (R OLED ) are equal or approximately equal. Approximately equal means that the difference between the two is less than 10%.

[0052] In this embodiment, the gate insulating layer of the first transistor resistor R1 and the second transistor resistor R2 can adopt a single-layer structure of silicon oxide with a thickness in the range of 80 to 120 nanometers to improve the stability and reliability of the first transistor resistor R1 and the second transistor resistor R2; or, the gate insulating layer of the first transistor resistor R1 and the second transistor resistor R2 is a stacked structure of hafnium oxide and aluminum oxide with a total thickness of 220 to 280 nanometers.

[0053] In this embodiment, the resistance value (R TFT ) and the resistance value of the second transistor resistor R2 (R TFT ) can be achieved by adjusting the dielectric constant of the gate insulating layer. For example, the dielectric constant of the gate insulating layer of the first transistor resistor R1 and the second transistor resistor R2 is less than 4.

[0054] In this embodiment, the active layer of the first transistor resistor R1 and the second transistor resistor R2 is IGZO, the atomic ratio of In:Ga:Zn in IGZO is 1:1:1, and 0.5% of tin element is doped in the active layer. This composition ratio can provide good threshold voltage stability while maintaining high mobility.

[0055] In order to achieve precise threshold voltage control, a back channel passivation layer is provided between the gate and the active layer. The passivation layer is a 5-nanometer-thick hafnium oxide film.

[0056] The source and drain of the first transistor resistor R1 and the second transistor resistor R2 are a three-layer metal structure of titanium / aluminum / titanium. The thickness of the bottom titanium layer is 20 nanometers, which is used to improve the contact characteristics with IGZO; the thickness of the middle layer aluminum is 200 nanometers, which serves as the main conductive layer; the thickness of the top titanium layer is 30 nanometers, which is used to prevent oxidation and migration of aluminum.

[0057] The gates of the first transistor resistor R1 and the second transistor resistor R2 are three-layer metal structures of molybdenum / aluminum / molybdenum with a total thickness of 300 nanometers. The thickness of the bottom and top molybdenum layers is 50 nanometers, and the thickness of the middle aluminum layer is 200 nanometers. This three-layer structure can ensure good conductivity and process compatibility at the same time.

[0058] The first transistor resistor R1 and the second transistor resistor R2 are both N-type thin film transistors. In particular, the first transistor resistor R1 and the second transistor resistor R2 are both N-type oxide semiconductor (eg, IGZO) thin film transistors.

[0059] In this embodiment, the first transistor resistor R1 and the second transistor resistor R2 are low temperature polysilicon thin film transistors.

[0060] The gate-drain voltage of the first transistor resistor R1 is lower than the threshold voltage of the first transistor resistor R1 (thin film transistor), and the gate-drain voltage of the second transistor resistor R2 is lower than the threshold voltage of the second transistor resistor R2 (thin film transistor).

[0061] The threshold voltages of the first transistor resistor R1 and the second transistor resistor R2 are greater than 0 volt.

[0062] In this embodiment, in order to make the first transistor resistor R1 and the second transistor resistor R2 work in the saturation region, the gate-drain voltage is set to be less than the threshold voltage.

[0063] The drain of the first transistor resistor R1 is electrically connected to one of the source and drain of the driving transistor T1, and the gate of the first transistor resistor R1 is electrically connected to the drain of the first transistor resistor R1; the drain of the second transistor resistor R2 is electrically connected to one of the source and drain of the driving transistor T1, and the gate of the second transistor resistor R2 is electrically connected to the drain of the second transistor resistor R2.

[0064] In this embodiment, by electrically connecting the gates of the first transistor resistor R1 and the second transistor resistor R2 to their respective drains, the transistor resistors can be made to work in a stable state, thereby preventing the resistance values ​​from drifting.

[0065] The ratio of the luminance of the first light emitting device OLED1 to the luminance of the second light emitting device OLED2 is in the range of 0.9 to 1.1. Preferably, the luminances of the first light emitting device OLED1 and the second light emitting device OLED2 are equal. The cathodes of the first light emitting device OLED1 and the second light emitting device OLED2 are electrically connected to the reference potential terminal Vss. In the present embodiment, the cathodes of the first light emitting device OLED1 and the second light emitting device OLED2 are electrically connected to the reference potential terminal Vss, and the voltage of the reference potential terminal may be, for example, -5 volts, -4 volts, -3 volts, -2 volts, or 0 volts.

[0066] like Figure 4 As shown, when the cathode and the anode of the first light emitting device OLED1 are short-circuited, the current flowing through the first transistor resistor R1 is greater than the current flowing through the second transistor resistor R2.

[0067] In this embodiment, the resistance value (R TFT ) and the resistance value of the second transistor resistor R2 (R TFT ), the resistance value of the first light emitting device OLED1 (R OLED ) and the resistance value of the second light emitting device OLED2 (R OLED), when the cathode and anode of the first light emitting device OLED1 are short-circuited, since the equivalent resistance of the short-circuited branch is 1 / 2 of the equivalent resistance of the non-short-circuited branch, the current flowing through the first transistor resistor R1 is twice the current flowing through the second transistor resistor R2. For example, when the total current is 15 microamperes, the current flowing through the first transistor resistor R1 is about 10 microamperes, and the current flowing through the second transistor resistor R2 is about 5 microamperes.

[0068] The brightness of the pixel unit in which the cathode and anode of the first light-emitting device OLED1 are short-circuited is lower than the brightness of the pixel unit in which neither the cathode and anode of the first light-emitting device OLED1 nor the cathode and anode of the second light-emitting device OLED2 are short-circuited, and the brightness of the pixel unit in which the cathode and anode of the first light-emitting device OLED1 are short-circuited is higher than one quarter of the brightness of the pixel unit in which neither the cathode and anode of the first light-emitting device OLED1 nor the cathode and anode of the second light-emitting device OLED2 are short-circuited.

[0069] In this embodiment, when the cathode and anode of the first light-emitting device OLED1 are short-circuited, the brightness of the pixel unit is mainly provided by the second light-emitting device OLED2. For example, when the brightness of the pixel unit in normal operation is 1000 nits, the brightness of the pixel unit after the short circuit is about 300 nits, which is greater than one-fourth of the normal pixel unit brightness (250 nits). This can effectively reduce the visual impact of dark spots and ensure that the display device can still provide a relatively uniform brightness output when a local pixel unit is short-circuited.

[0070] The resistance value of the first transistor resistor R1 (R TFT ) and the resistance value of the second transistor resistor R2 (R TFT ) changes less than 1% of its resistance value with each 1°C increase in temperature. For example, within the operating temperature range of 25°C to 85°C, the resistance value of the transistor resistor does not change by more than ±30% of its nominal value. To achieve this goal, in this embodiment, rare earth elements such as lanthanum and cerium are doped into the channel region of the transistor resistor at a concentration of 1×10^18 / cm 3 The introduction of these rare earth elements can effectively improve the temperature stability of transistor resistance and reduce the impact of temperature changes on resistance values.

[0071] The resistance value of the first transistor resistor R1 (R TFT ) and the resistance value of the second transistor resistor R2 (R TFT ) The change in resistance for each 1 volt increase in operating voltage is less than 0.1% of its resistance value.

[0072] In this embodiment, nanocrystals are formed in the channel region of the transistor resistor, and the grain size of the nanocrystals is controlled within the range of 20 nanometers to 50 nanometers. The nanocrystals can improve the carrier mobility in the channel region, while reducing the influence of the operating voltage change on the resistance value, ensuring the stability of the transistor resistor under different operating voltages (especially high voltages), and effectively preventing the drift of the resistance value.

[0073] In the display device provided in the embodiment of the present application, each pixel unit includes two light emitting devices, and each light emitting device is electrically connected to the driving transistor T1 through a transistor resistor. TFT ) and the resistance value of the light-emitting device (R OLED ), when the cathode and anode of one of the light-emitting devices are short-circuited, the current of the short-circuited branch will not be significantly greater than the current of the non-short-circuited branch, so that the light-emitting device that is not short-circuited can continue to emit light. This design does not require manual positioning of the dark spot and laser repair, and can automatically improve the dark spot problem, saving human resources and equipment resources consumed by using laser cutting to cut the circuit at the anode of the pixel unit with a cathode and anode short-circuit phenomenon, improving production efficiency and reducing production costs.

[0074] The embodiments of the present application are described in detail above, and the contents of this specification should not be construed as limiting the scope of protection of the present application.

Claims

1. A display device, characterized in that: include: A plurality of pixel units, each of which is provided with a pixel circuit, wherein the pixel circuit comprises: Driver transistor; a first light emitting device; a second light emitting device; a first transistor resistor; and a second transistor resistor; Among them, the anode of the first light-emitting device is electrically connected to the first end of the first transistor resistor, the anode of the second light-emitting device is electrically connected to the first end of the second transistor resistor, the cathode of the first light-emitting device is electrically connected to the cathode of the second light-emitting device, and the second end of the first transistor resistor and the second end of the second transistor resistor are both electrically connected to one of the source and the drain of the driving transistor.

2. The display device according to claim 1, characterized in that A ratio of a resistance value of the first transistor resistor to a resistance value of the first light emitting device and a ratio of a resistance value of the second transistor resistor to a resistance value of the second light emitting device are both in a range of 0.5 to 2.

3. The display device according to claim 1, characterized in that The first transistor resistor and the second transistor resistor are both N-type thin film transistors; The gate-drain voltage of the first transistor resistor is less than the threshold voltage of the first transistor resistor; A gate-drain voltage of the second transistor resistor is less than a threshold voltage of the second transistor resistor.

4. The display device according to claim 3, characterized in that: The threshold voltages of the first transistor resistor and the second transistor resistor are greater than 0 volts.

5. The display device according to claim 3, characterized in that: A ratio of a resistance value of the first transistor resistor to a resistance value of the first light emitting device is in a range of 0.8 to 1.2; A ratio of a resistance value of the second transistor resistor to a resistance value of the second light emitting device is in a range of 0.8 to 1.

2.

6. The display device according to claim 5, characterized in that: The resistance values ​​of the first transistor resistor and the second transistor resistor are greater than 10 6 Ohm and less than 10 8 ohm.

7. The display device according to claim 3, characterized in that: The drain of the first transistor resistor is electrically connected to one of the source and the drain of the driving transistor, and the gate of the first transistor resistor is electrically connected to the drain of the first transistor resistor; The drain of the second transistor resistor is electrically connected to one of the source and the drain of the driving transistor, and the gate of the second transistor resistor is electrically connected to the drain of the second transistor resistor.

8. The display device according to claim 1, characterized in that: A ratio of the light emitting brightness of the first light emitting device to the light emitting brightness of the second light emitting device is in a range of 0.9 to 1.

1.

9. The display device according to claim 1, characterized in that: The cathodes of the first light emitting device and the second light emitting device are electrically connected to a reference potential terminal.

10. The display device according to claim 1, characterized in that The brightness of the pixel unit in which the cathode and anode of the first light-emitting device are short-circuited is lower than the brightness of the pixel unit in which neither the cathode and anode of the first light-emitting device nor the cathode and anode of the second light-emitting device are short-circuited, and the brightness of the pixel unit in which the cathode and anode of the first light-emitting device are short-circuited is higher than one quarter of the brightness of the pixel unit in which neither the cathode and anode of the first light-emitting device nor the cathode and anode of the second light-emitting device are short-circuited.

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