Display module, temperature detection method thereof, and display device

Abstract

The present disclosure provides a display module, a temperature detection method thereof, and a display device. The display module includes a display panel, the display panel includes a touch layer disposed on a substrate, the touch layer includes a plurality of touch sensing electrodes, and the display module further includes a temperature detection circuit, the temperature detection circuit includes: a first sampling circuit electrically connected with the plurality of touch sensing electrodes to receive sensing charges from the touch sensing electrodes and convert the sensing charges into a first sampling voltage; and an amplification circuit configured to amplify the first sampling voltage to obtain a second sampling voltage, so that the display panel obtains the temperature of a corresponding point on the touch sensing electrode according to the second sampling voltage. The embodiment of the present disclosure can obtain the two-dimensional temperature distribution of multiple points of the full-screen in the pixel area of the panel at a lower cost.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a display module, a temperature detection method for the display module, and a display device. Background Technology

[0002] With organic light-emitting diodes (OLEDs) OLED (Emitting Diode) products are rapidly evolving towards higher brightness, higher refresh rates, larger sizes, and flexible forms. The issue of panel temperature rise during operation is increasingly becoming a key bottleneck affecting their reliability, lifespan, and display performance. Excessive temperature accelerates the aging of OLED materials, leading to brightness decay, color shift, and even irreversible pixel failure.

[0003] Therefore, there is an urgent need for a solution that can monitor panel temperature in real time and accurately. Summary of the Invention

[0004] To address at least one of the aforementioned problems, a first aspect of this disclosure provides a display module including a display panel. The display panel includes a touch layer disposed on a substrate, the touch layer including a plurality of touch sensing electrodes. The display module further includes a temperature detection circuit, the temperature detection circuit including: The first sampling circuit is electrically connected to multiple touch sensing electrodes to receive sensing charges from the touch sensing electrodes and convert the sensing charges into a first sampling voltage. An amplifier circuit amplifies the first sampling voltage to obtain a second sampling voltage, so that the display module can obtain the temperature of the corresponding point on the touch sensing electrode based on the second sampling voltage.

[0005] Optionally, the first sampling circuit includes: a first operational amplifier, a first capacitor, and a first resistor. The inverting input of the first operational amplifier is electrically connected to multiple touch sensing electrodes, the non-inverting input is grounded, and the first capacitor and the first resistor are respectively connected across the inverting input and the output of the first operational amplifier.

[0006] Optionally, the first operational amplifier is a transconductance operational amplifier.

[0007] Optionally, the display panel further includes: a first insulating layer disposed on the surface of the film layer containing the touch sensing electrodes near the substrate, and a shielding layer of conductive material disposed on the surface of the first insulating layer near the substrate. The orthographic projection of the shielding layer onto the substrate covers the orthographic projection of multiple touch sensing electrodes onto the substrate. The temperature detection circuit also includes a buffer circuit, which is a follower circuit including a second operational amplifier. The non-inverting input of the second operational amplifier is electrically connected to the touch sensing electrode, the inverting input is electrically connected to the output of the second operational amplifier, and the output is electrically connected to the shielding layer.

[0008] Optionally, the amplifier circuit includes a third operational amplifier, a second resistor, and a third resistor. The non-inverting input of the third operational amplifier receives the first sampled voltage, and the inverting input is electrically connected to the first end of the second resistor and the first end of the third resistor. The second end of the second resistor is grounded, and the second end of the third resistor is electrically connected to the output of the third operational amplifier, which serves as the output of the amplifier circuit.

[0009] Optionally, the temperature detection circuit further includes a low-pass filter circuit, used to filter the received second sample voltage and output a third sample voltage.

[0010] Optionally, the low-pass filter circuit includes: a fourth operational amplifier, a fourth resistor, a fifth resistor, a second capacitor, and a third capacitor. The fourth and fifth resistors are connected in series between the output of the amplifier circuit and the non-inverting input of the fourth operational amplifier. The first end of the second capacitor is electrically connected to the non-inverting input of the fourth operational amplifier, and the second end is grounded. The first end of the third capacitor is electrically connected to the common connection of the fourth and fifth resistors, and the second end is electrically connected to the output of the fourth operational amplifier. The inverting input of the fourth operational amplifier is electrically connected to the output of the fourth operational amplifier, which serves as the output of the low-pass filter circuit.

[0011] Optionally, the gain range of the amplifier circuit is greater than or equal to 50 and less than or equal to 200, and / or the resistance of the first resistor is greater than or equal to 50MΩ and less than or equal to 200MΩ, and the capacitance of the first capacitor is greater than or equal to 0.5pF and less than or equal to 2pF.

[0012] Optionally, the touch layer also includes multiple touch driving electrodes that are electrically isolated from and correspond one-to-one with the multiple touch sensing electrodes. The cutoff frequency of the low-pass filter circuit is less than the Nyquist frequency, which is half the signal frequency of the sampling driving signal received by the touch driving electrode during temperature detection.

[0013] A second aspect of this disclosure provides a display device including the display module described above.

[0014] A third aspect of this disclosure provides a temperature detection method applied to the display module described above. The display module further includes a processing unit, and the touch layer further includes a plurality of touch driving electrodes that are electrically isolated from and correspond one-to-one with the plurality of touch sensing electrodes. When performing temperature detection, the processing unit sends a sampling drive signal to the touch driving electrode. The touch sensing electrode generates a sensing charge based on the mutual capacitance between itself and the corresponding touch driving electrode. The temperature detection circuit generates a first sampling voltage in response to the received sensing capacitance and amplifies the first sampling voltage to obtain a second sampling voltage. The processing unit acquires the second sampling voltage and determines the current temperature of the location based on the pre-stored relationship between the temperature at the location of the touch sensing electrode and the sampling voltage.

[0015] The beneficial effects of this disclosure are as follows: This disclosure addresses existing problems by providing a display module, a temperature detection method for the display module, and a display device. It provides a temperature detection circuit including a first sampling circuit and an amplification circuit. The first sampling circuit receives the sensing charge from the touch sensing electrodes of the display panel's touch layer, converts it into a first sampling voltage, and amplifies it to generate a second sampling voltage. This allows the display module to determine the temperature of the corresponding point on the touch sensing electrode based on the second sampling voltage. By utilizing multiple touch sensing electrodes built into the display panel, the temperature detection circuit can acquire the temperature of various points on the screen in real time and online while the device is running, providing fast and reliable protection for the display panel, improving display performance and product reliability, and extending product lifespan. This method has broad application prospects. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This diagram illustrates a display module according to an embodiment of the present disclosure; Figure 2 This is a schematic cross-sectional view of a display module according to an embodiment of the present disclosure; Figure 3 This is a schematic diagram of a temperature detection circuit in a display module according to an embodiment of the present disclosure; Figure 4 A schematic diagram of a temperature detection circuit in a display module according to another embodiment of the present disclosure is shown; Figure 5 This is a schematic diagram showing the projection relationship between the touch sensing electrodes and touch driving electrodes of the touch layer of the display module according to an embodiment of the present disclosure and the shielding layer; Figure 6 A schematic diagram of a temperature detection circuit in a display module according to another embodiment of the present disclosure is shown. Detailed Implementation

[0018] To more clearly illustrate this disclosure, the preferred embodiments and accompanying drawings will be used for further description. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of this disclosure.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in this disclosure should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an," "a," or "the," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising," "including," etc., mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms "connected," "linked," etc., are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Furthermore, in this disclosure, an electrical connection can be a direct connection or a connection of transistors separated by a certain conducting element.

[0020] Currently, the industry mainly adopts three mainstream temperature monitoring solutions for display panels. The first is point-contact temperature measurement, which involves attaching a few discrete thermistors or digital temperature sensors near the display panel bezel or driver chip, and obtaining the corresponding temperature data by reading the data from each thermistor or digital temperature sensor. This method is low-cost, but it can only reflect the temperature of a few fixed points and cannot capture the temperature of the internal display area, especially the local high-temperature "hot spots" at the pixel level, resulting in a monitoring blind zone. The second is infrared thermal imaging, which uses an external infrared thermal imager to scan the screen. This method can obtain a two-dimensional temperature distribution, but the equipment is expensive and bulky, making it difficult to integrate into consumer electronics devices. It cannot monitor the temperature and adjust parameters in real time during device use, and is easily affected by visible light emitted by the screen itself, affecting measurement accuracy. The third is integrated temperature sensor, which integrates a temperature sensor into the display driver chip or touch chip. While this is easy to integrate, it still senses the temperature of the chip package itself, resulting in a difference and thermal hysteresis between the sensor and the actual temperature distribution of the pixel area of ​​the display panel, and cannot achieve area-wide temperature measurement.

[0021] Therefore, there is an urgent need to provide a method that can overcome the above-mentioned shortcomings in temperature monitoring and can achieve real-time online and accurate two-dimensional surface temperature monitoring of the display panel at a low cost.

[0022] In view of the above, this disclosure provides a display module, including a display panel, the display panel including: a touch layer disposed on a substrate, the touch layer including a plurality of touch sensing electrodes, the display module further including a temperature detection circuit, the temperature detection circuit including: The first sampling circuit is electrically connected to multiple touch sensing electrodes to receive sensing charges from the touch sensing electrodes and convert the sensing charges into a first sampling voltage. An amplification circuit amplifies the first sampling voltage to obtain a second sampling voltage, so that the display module can obtain the temperature of the corresponding point on the touch sensing electrode based on the second sampling voltage.

[0023] In this embodiment, a temperature detection circuit including a first sampling circuit and an amplification circuit is provided. The first sampling circuit receives the sensing charge from the touch sensing electrode of the touch layer of the display panel and converts it into a first sampling voltage. After being amplified by the amplification circuit, a second sampling voltage is generated. This enables the display module to determine the temperature of the corresponding point of the touch sensing electrode based on the second sampling voltage. Thus, the temperature detection circuit can use multiple touch sensing electrodes built into the display panel to obtain the temperature of each point in the screen in real time and online while the device is running. This provides fast and reliable protection for the display panel, improves the display effect and product reliability, and extends the product's service life.

[0024] The specific structure and function of the display module of this disclosure embodiment are described below with reference to the accompanying drawings and specific embodiments.

[0025] Reference Figure 1 and Figure 2 As shown, the display module includes a display panel 1, which includes a touch layer 101 disposed on a substrate 100. The touch layer 101 includes a plurality of touch sensing electrodes Rx and a plurality of touch driving electrodes Tx that are disposed in one-to-one correspondence with the plurality of touch sensing electrodes Rx and are electrically isolated from each other.

[0026] Specifically, such as Figure 1 As shown, the display panel 1 includes a display area AA and a non-display area NA disposed around the display area AA. Multiple touch sensing electrodes Rx and multiple touch driving electrodes Tx are disposed within the display area AA. The orthographic projections of the multiple touch sensing electrodes Rx onto the substrate 100 are arranged in an array, and the orthographic projections of the multiple touch driving electrodes Tx onto the substrate 100 are also arranged in an array. The touch layer 101 includes a layer along a first direction (e.g., ...). Figure 1 N columns of touch sensing electrodes Rx arranged in the X direction and along the second direction (e.g., in the X direction) and along the second direction (e.g., in the X direction) Figure 1M rows of touch driving electrodes Tx are arranged in the Y direction (center). Touch sensing electrodes Rx in the same column are electrically connected via sensing connection line Lr, and touch driving electrodes Tx in the same row are electrically connected via driving connection line Lt. For example, although not shown, each row of touch driving electrodes Tx can be electrically connected to the touch chip via touch traces disposed in the non-display area NA, and each column of touch sensing electrodes Rx can be electrically connected to the touch chip via touch traces disposed in the non-display area NA. During touch sensing, the touch sensing function is realized by sending a driving signal to each row of touch driving electrodes Tx and by receiving a sensing signal from the touch sensing electrodes Rx.

[0027] It should be noted that, Figure 1 The layout, pattern, and film layer of the touch sensing electrode Rx and touch driving electrode Tx are for illustrative purposes only and are not intended to limit. Any touch layer structure that is arrayed and electrically isolated from each other and generates a sensing signal by mutual capacitance in response to a driving signal is protected by this disclosure.

[0028] For example, such as Figure 2 As shown, the touch layer 101 may include a first conductive layer 111, a second conductive layer 121, and a second insulating layer 131 disposed between the first conductive layer 111 and the second conductive layer 121. Optionally, a plurality of touch sensing electrodes Rx and a plurality of touch driving electrodes Tx may be disposed in the first conductive layer 111. One of the sensing connection line Lr for connecting the touch sensing electrode Rx and the driving connection line Lt for connecting the touch driving electrode Tx may be disposed in the first conductive layer 111, and the other may be disposed in the second conductive layer 121. An electrical connection relationship is formed by forming a jumper through the via 131, thereby electrically isolating the touch sensing electrode Rx from the touch driving electrode Tx. When the touch driving electrode Tx receives a driving signal, a mutual capacitance Cm is formed between the corresponding touch sensing electrode and Rx and the touch driving electrode Tx.

[0029] In this disclosure embodiment, reference continues to be made to Figure 1 As shown, the display module also includes a temperature detection circuit 20. Exemplarily, the temperature detection circuit 20 is disposed on the printed circuit board 2 of the display module, which may also be referred to as a "PCBA". When the temperature detection circuit 20 is disposed on the printed circuit board 2, it avoids occupying space in the non-display area NA of the display panel 1, avoids layout and wiring complications, and avoids changing the hardware settings of the display panel. The printed circuit board 2 can be electrically connected to the display panel 1 via a flexible circuit board 3. For example, one end of the flexible circuit board 3 is electrically connected to a plurality of second pads on the display panel 1 via a plurality of first pads, and the other end is electrically connected to a fourth pad on the printed circuit board via a plurality of third pads.

[0030] Those skilled in the art should understand that this disclosure is not intended to limit the location of the temperature detection circuit 20. If the functionality and hardware support of the display driver chip allow, the temperature detection circuit 20 can be implemented in the display driver chip, which will not be elaborated here.

[0031] It should also be noted that the display panel mentioned in this article is not intended to be limited to OLED display panels; it can also be a light-emitting diode (LED) display panel. Quantum dot light-emitting diode (QLED) display panels, micro light-emitting diode (Micro LED) display panels, and sub-millimeter light-emitting diode (Mini LED) display panels. Emitting Diode (Mini LED) display panels and any other touch display panels with the aforementioned touch layer are protected under this disclosure.

[0032] In this disclosure embodiment, reference continues to be made to Figure 1 As shown, the temperature detection circuit includes: a first sampling circuit 201 and an amplifier circuit 202.

[0033] The first sampling circuit 201 is electrically connected to multiple touch sensing electrodes Rx to receive sensing charges from the touch sensing electrodes and convert the sensing charges into a first sampling voltage Vtia. The amplifier circuit 202 amplifies the first sampling voltage Vtia to obtain a second sampling voltage Vpga, so that the display module can obtain the temperature of the corresponding point on the touch sensing electrode Rx according to the second sampling voltage Vpga.

[0034] Specifically, in combination Figure 1 and Figure 3 As shown, the first sampling circuit 201 includes a first operational amplifier U1, a first capacitor C1, and a first resistor R1. The inverting input terminal "-" of the first operational amplifier U1 is electrically connected to multiple touch sensing electrodes Rx, and the non-inverting input terminal "+" is grounded. The first capacitor C1 and the first resistor R1 are respectively connected between the inverting input terminal "-" and the output terminal of the first operational amplifier U1. For example, the first operational amplifier U1 is connected to the analog ground terminal AGND.

[0035] It should be noted that, in order to simplify the size of the temperature sensor and the printed circuit board 2, in this embodiment, the display module may only have one set of a first sampling circuit 201 and an amplification circuit 202. That is, the input terminal of the first sampling circuit 201 is electrically connected to multiple touch sensing electrodes Rx, i.e., the input terminal of the first sampling circuit 201 is electrically connected to N columns of touch sensing electrodes Rx in the display panel 1 via a first connection line L1. Of course, the first connection line L1 may include multiple sub-connection lines respectively disposed in the printed circuit board 2, the flexible circuit board 3, and the display panel 1. During temperature detection, corresponding to the sampling driving signal received by each row of touch driving electrodes Tx, the sampling sensing signal V_Rx from each column of touch sensing electrodes Rx is read in a time-division manner.

[0036] Optionally, such as Figure 1 As shown, a selection circuit 12 is also included between the input terminal of the first sampling circuit 201 and each column of touch sensing electrodes Rx. The selection circuit can time-divisionally select the electrical connection between the first sampling circuit 201 and each column of touch electrodes Rx according to a control signal. Exemplarily, the selection circuit includes a selection switch, which, in response to a control signal, time-divisionally selects the inverting input terminal "-" of the first sampling circuit 201 to be electrically connected to each column of touch electrodes Rx. The control signal can come from a processing unit located in the display driver chip. It should be understood that, considering spatial layout, this disclosure is not intended to limit the specific form and location of the selection circuit; the selection circuit can be located in the printed circuit board 2, in the non-display area of ​​the display panel 1, or in the display driver chip.

[0037] With this configuration, the display module can be equipped with only a first sampling circuit 201 and an amplification circuit 202. When the temperature detection circuit 20 is set on the printed circuit board 2, its input terminal occupies only one pad on the printed circuit board 2 and the display panel, respectively. Alternatively, when the temperature detection circuit 20 is set in the display driver chip, its input terminal occupies only one pin of the display driver chip. This allows for the realization of two-dimensional temperature detection within the screen with minimal space requirements and avoids excessive pad space requirements.

[0038] Continuing with this example, for the first sampling circuit 201, based on the "virtual short" characteristic of the operational amplifier, the inverting input terminal "-" potential is forced to follow the non-inverting input terminal "+", that is... =Vagnd, where Vagnd represents the simulated ground potential, thus forcing the touch sensing electrode Rx to be maintained at the simulated ground potential, forming a stable "virtual ground" node. The feedback network between the inverting input terminal "-" and the output terminal of the first operational amplifier U1 is formed by a precision integrating capacitor composed of the first capacitor C1 and the first resistor R1 connected in parallel with a feedback resistor. When the touch driving electrode Tx is subjected to an excitation voltage Vtx, charge is injected into the mutual capacitance Cm between the corresponding touch sensing electrode Rx and the touch driving electrode Tx, and the voltage change across the mutual capacitance Cm is ΔVtx. According to the capacitance formula, the amount of charge coupled to the touch sensing electrode Rx is: ΔQ = Cm × ΔVtx. Since the touch sensing electrode Rx is forcibly maintained at the virtual ground potential, these charges cannot remain on the touch sensing electrode Rx. According to Kirchhoff's current law, all the charge injected into the mutual capacitance Cm must pass through the feedback network.

[0039] Optionally, the resistance value of the first resistor R1 is set as large as possible, and the path of the first resistor R1 is equivalent to a virtual open circuit, so that the high-frequency sensing charge from the touch sensing electrode Rx mainly flows to the first capacitor C1. The first capacitor C1 acts as an integrating capacitor, and the charge accumulated on it generates the output voltage Vtia of the first sampling circuit 201, which has the following relationship: The negative sign indicates phase reversal. In other words, by setting the first sampling circuit 201, the sensed charge ΔQ from the touch sensing electrode Rx can be completely converted into a voltage form and output as the first sampling voltage Vtia via the integrating capacitor in the RC integrating circuit based on the first operational amplifier U1.

[0040] Furthermore, in the embodiments of this disclosure, the temperature of the point where the mutual capacitance between the touch sensing electrode and the corresponding touch driving electrode is located is sampled in the form of a change in the sensed charge in the mutual capacitance. In order to reflect the small capacitance change of the sensed mutual capacitance based on the temperature change of the corresponding point as much as possible in the first sampling voltage Vtia, the capacitance value of the first capacitor C1, which is the denominator of the expression for calculating Vtia, should be as small as possible, so as to accurately monitor the temperature change of each point and achieve high sensitivity.

[0041] Optionally, the resistance of the first resistor R1 is greater than or equal to 50MΩ and less than or equal to 200MΩ, and the capacitance of the first capacitor C1 is greater than or equal to 0.5pF and less than or equal to 2pF. For example, the first resistor R1 can be 100MΩ and the first capacitor C1 can be 1pF.

[0042] Considering the parasitic capacitances existing between the various film layers in the display panel, and the negligible change in mutual capacitance compared to the surrounding large parasitic capacitances, the first operational amplifier U1 can optionally be a transconductance operational amplifier. Only by setting the first operational amplifier as a transconductance operational amplifier can a practical circuit architecture that simultaneously achieves high sensitivity, parasitic capacitance insensitivity, and low noise be realized.

[0043] Continuing this example, amplifier circuit 202 includes a third operational amplifier U3, a second resistor R2, and a third resistor R3. Specifically, the non-inverting input terminal "+" of the third operational amplifier U3 receives the first sampled voltage Vtia, and the inverting input terminal "-" is electrically connected to the first terminals of the second resistor R2 and the third resistor R3. The second terminal of the second resistor R2 is grounded, for example, analog ground AGND. The second terminal of the third resistor R3 is electrically connected to the output terminal of the third operational amplifier U3, which serves as the output terminal of amplifier circuit 202. The third operational amplifier U3, the second resistor R2, and the third resistor R3 form a negative feedback voltage amplifier circuit, and the amplification factor is determined by the second resistor R2 and the third resistor R3, i.e., the output gain. .

[0044] Optionally, the gain range of the amplifier circuit 202 is greater than or equal to 50 and less than or equal to 200. For example, the gain of the amplifier circuit 202 is 100, the second resistor R2 is 1kΩ, and the third resistor R3 is 99kΩ.

[0045] Optionally, the second resistor R2 and the third resistor R3 are 0.1% precision thin-film resistors to ensure gain stability.

[0046] The amplitude of the first sampled voltage Vtia obtained after sampling by the first sampling circuit 201 is only in the millivolt range. By setting up the amplifier circuit 202, the first sampled voltage Vtia signal can be amplified to an amplitude suitable for subsequent processing. In addition, the third operational amplifier U3 has a high input impedance, which can ensure that it will not cause a load effect on the previous first sampling circuit 201.

[0047] In another alternative embodiment, refer to Figure 4 and Figure 2 As shown, in addition to the first sampling circuit 201 and the amplification circuit 202 described above, the temperature detection circuit 20 also includes a buffer circuit 203, which is a follower circuit including the second operational amplifier U2. Specifically, the non-inverting input terminal "+" of the second operational amplifier U2 is electrically connected to the touch sensing electrode Rx, the inverting input terminal "-" is electrically connected to the output terminal of the second operational amplifier U2, and the output terminal is electrically connected to the shielding layer 103.

[0048] Specifically, refer to Figure 2 and Figure 5As shown, the display panel 1 further includes: a first insulating layer 104 disposed on the surface of the film layer 111 containing the touch sensing electrodes Rx near the substrate 100, and a shielding layer 103 of conductive material disposed on the surface of the first insulating layer 104 near the substrate 100. Exemplarily, the shielding layer 103 can be a single piece of mesh-like material, a solid copper foil, or an ITO film, and the orthographic projection of the shielding layer 103 onto the substrate 100 covers the orthographic projections of the multiple touch sensing electrodes Rx onto the substrate 100. Figure 2 As shown, a shielding layer 103 is disposed between the lower display and driving layer 102 and the touch layer 101 for signal shielding protection. Figure 5 As shown, the coverage relationship of the above orthographic projection range means that regardless of whether the shielding layer 103 is a grid or a solid film layer, its overall pattern is roughly complete, and the orthographic projections of each touch sensing electrode Rx of the touch layer on the substrate 100 all fall within its projection range on the substrate 100. It should be understood that the shielding layer 103 has openings or traces so that each touch sensing electrode or touch driving electrode in the touch layer can be connected to other circuits or traces when needed. In this embodiment, the output terminal of the buffer circuit 203 is electrically connected to the shielding layer 103 via a connecting line.

[0049] Specifically, the buffer circuit 203, configured as a unity-gain follower circuit, continuously monitors the potential of the touch sensing electrode Rx at the non-inverting input "+" of the second operational amplifier U2. This point is also forced to "virtual ground" by the inverting input "-" of the first sampling circuit 201. Due to the characteristics of the follower circuit, its output accurately replicates the voltage at the non-inverting input, i.e., Vshield = V_Rx. Since the output of the buffer circuit 203 is electrically connected to the shielding layer 103, the potential of the shielding layer 103 constantly tracks the potential of the sensing drive electrode Rx. Therefore, the voltage difference across the parasitic capacitance between the shielding layer 103 and the touch sensing electrode Rx is always 0V. According to the capacitance-current formula... When the voltage difference between the two plates of the capacitor is constant at 0, no current flows through the parasitic capacitance. Therefore, it can be ensured that all the sensing charge injected by the mutual capacitance Cm between the touch driving electrode Tx and the touch sensing electrode Rx flows to the feedback capacitor of the first sampling circuit 201, i.e., the first capacitor C1, and is not diverted by the parasitic capacitance, thus improving the detection accuracy.

[0050] In some alternative embodiments, the temperature detection circuit 20 further includes a low-pass filter circuit 204, used to filter the received second sampling voltage Vpga and output a third sampling voltage V_out. For example, as... Figure 6As shown, the temperature detection circuit 20 comprises at least a first sampling circuit 201, an amplification circuit 202, a buffer circuit 203, and a low-pass filter circuit 204. However, those skilled in the art should understand that this disclosure is not limited thereto; optionally, the temperature detection circuit 20 may also include... Figure 3 The example structure shown adds a low-pass filter circuit 204, meaning the temperature detection circuit 20 can also consist of at least a first sampling circuit 201, an amplifier circuit 202, and a low-pass filter circuit 204.

[0051] By further connecting a low-pass filter circuit 204 to the output of the amplifier circuit 202, high-frequency switching noise and potential radio frequency interference mixed in the first sampling voltage Vpga can be filtered out.

[0052] continue Figure 6 For example, the low-pass filter circuit 204 includes: a fourth operational amplifier U4, a fourth resistor R4, a fifth resistor R5, a second capacitor C2, and a third capacitor C3. The fourth resistor R4 and the fifth resistor R5 are connected in series between the output of the amplifier circuit 202 and the non-inverting input terminal "+" of the fourth operational amplifier U4. The first terminal of the second capacitor C2 is electrically connected to the non-inverting input terminal "+" of the fourth operational amplifier U4, and the second terminal is grounded, i.e., analog ground AGND. The first terminal of the third capacitor C3 is electrically connected to the common connection terminal of the fourth resistor R4 and the fifth resistor R5, and the second terminal is electrically connected to the output terminal of the fourth operational amplifier U4. The inverting input terminal "-" of the fourth operational amplifier U4 is electrically connected to the output terminal of the fourth operational amplifier U4, which serves as the output terminal of the low-pass filter circuit 204.

[0053] It should be noted that the low-pass filter circuit 204 constitutes a second-order Sallen-Key filter. By utilizing a second-order Sallen-Key filter, only signals within a specific frequency range can be allowed to pass while suppressing signals of other frequencies, and a steeper roll-off characteristic is provided, thus offering better frequency selection.

[0054] Because the first sampling circuit 201 converts the sensed charge in the mutual capacitance into the form of the first sampling voltage Vtia through the integrating capacitor and then amplifies it through the amplifier circuit 202 to obtain the sampling signal in the form of the second sampling voltage Vpga, it is also necessary to avoid the "aliasing distortion" problem when passing through the low-pass filter circuit. It is also necessary to consider the problem of high-frequency components folding into low frequencies, which affects the authenticity and accuracy of the output.

[0055] Optionally, the cutoff frequency fc of the low-pass filter circuit 204 is less than the Nyquist frequency fnyquist, where the Nyquist frequency fnyquist is half the signal frequency of the sampling drive signal received by the touch drive electrode Tx during temperature detection.

[0056] It should be noted that when aliasing distortion occurs in the low-frequency filter circuit, high-frequency signals above the Nyquist frequency are folded into signals whose frequency is the difference between the sampling frequency of the low-frequency filter circuit's output signal and the Nyquist frequency. This results in these high-frequency signals not being properly filtered out and subsequently unable to be identified and filtered, thus affecting the accuracy of subsequent processing results. Because the Nyquist frequency is half the sampling frequency, setting the cutoff frequency fc of the low-pass filter circuit 204 to be less than the Nyquist frequency can prevent aliasing distortion from occurring in the low-pass filter circuit when the first sampling voltage Vpga passes through it.

[0057] It should be noted that in the embodiments of this disclosure, the frequency of the sampling signal after the low-pass filter circuit is essentially the same as the frequency of the high-frequency signal that drives the touch driving electrode Tx during the temperature detection process, causing the touch sensing electrode Rx to generate sensing charge. Therefore, in this example, the Nyquist frequency fnyquist is half the signal frequency of the sampling driving signal received by the touch driving electrode Tx during temperature detection.

[0058] It should be noted that, after filtering out high-frequency signals, the first sampling voltage of the temperature detection circuit 20 described above, as the output signal V_out of the temperature detection circuit 20, can be obtained via, as follows: Figure 1 The third connection L3 shown is transmitted to the display driver chip 11 of the display panel 1, and processed by the processing unit integrated in the display driver chip 11 to obtain the temperature of the corresponding point. It should be understood that the third connection L3 may include multiple sub-connection lines disposed on the printed circuit board 2, the flexible circuit board 3 and the display panel 1 to realize the electrical connection from the output terminal of the temperature detection circuit 20 to the processing unit.

[0059] The following describes, through a specific example, the implementation process of temperature detection using a temperature detection circuit in the display module of this disclosure embodiment.

[0060] Before leaving the factory, the display module is subjected to temperature detection circuit 20 to measure the reference first sampling voltage at the intersection of all touch sensing electrodes Rx and touch driving electrodes Tx on the display panel 1 at multiple known temperature points, such as 25℃, 40℃, and 60℃, under constant temperature conditions. Based on these measurements, a three-dimensional lookup table of "position-temperature-sampling voltage" is established or the temperature drift coefficient of each point is fitted. The lookup table or the temperature coefficient of each point is stored in the storage unit for subsequent processing. It should be understood that the storage unit can also be integrated inside the display driver chip.

[0061] Before leaving the factory, during the non-temperature detection stage, the display module can normally use the touch layer to perform touch scanning detection under the drive of the touch chip. During the touch scanning stage in the use process after leaving the factory, the display module can also normally use the touch layer to perform touch scanning detection under the drive of the touch chip to recognize the user's touch operation commands on the display panel.

[0062] After leaving the factory, during the use of the display module, users can activate temperature detection-related commands based on touch operations on the display panel, so that the display panel temporarily jumps out of the touch scanning stage and enters the temperature detection stage by using the touch layer and temperature detection circuit. Alternatively, the display module can preset periodic temperature detection commands according to user settings, so that each preset stage pauses touch scanning and starts the temperature detection stage during the interval of touch scanning or during system idle periods.

[0063] During the temperature detection phase, the processing unit integrated in the display driver chip 11 can control the multiplexer to select a row of touch driving electrodes Tx in sequence and apply a sampling driving signal of a preset frequency to the row of touch driving electrodes Tx. The preset frequency is, for example, 100kHz and the amplitude is 3.3V AC excitation signal.

[0064] In response to the sampling drive signal, each column of touch sensing electrodes Rx, which intersects with the currently activated row of touch driving electrodes Tx, is coupled to a weak sensing charge through mutual capacitance Cm. Each touch sensing electrode Rx is sequentially electrically connected to the temperature detection circuit 20, causing the temperature detection circuit to start working. The sensing charge of each touch sensing electrode Rx is converted into a first sampling voltage Vtia by the first sampling circuit 201, and then amplified by the amplifier circuit 202 to generate a second sampling voltage Vpga. After that, the high-frequency switching noise and potential radio frequency interference in the second sampling voltage Vpga can be filtered out by the low-pass filter circuit 204, and the output voltage signal V_out is output to the processing unit.

[0065] The processing unit calculates the temperature value of the point corresponding to the touch sensing electrode Rx based on the received voltage signal V_out, according to a pre-stored lookup table or the temperature drift coefficient of each point. Specifically, if a lookup table is pre-stored, the temperature value corresponding to the current voltage signal V_out can be obtained by interpolation through the lookup table; if a temperature coefficient is pre-stored, the output voltage signal V_out can be directly converted into the current temperature value based on the temperature coefficient. After traversing the temperature detection and calculation at all points of the column touch sensing electrodes Rx corresponding to all row touch driving electrodes Tx, a temperature distribution map corresponding to the front display panel is generated, thus completing one temperature detection process.

[0066] After the temperature detection process is completed once, the display module exits the temperature detection stage and returns to the touch mode, so that the touch layer can continue to perform normal touch scanning detection.

[0067] Those skilled in the art should understand that after obtaining the temperature distribution of the display panel, the display module can provide these temperature values ​​to the display driver chip according to preset software or system settings, so that the display driver chip can determine the adjustment and update of the corresponding display driver parameters based on the current temperature values ​​of each point, and / or when a preset number of points in the display panel are detected to have problems such as overheating, the display device or circuit in the display panel can be cooled by adjusting parameters or temporarily cutting off power according to preset instructions, so as to delay the aging of the display panel and improve the service life of the display panel.

[0068] As can be seen, the above structural design enables the use of readily available touch electrode grids with hundreds or thousands of intersections across the panel to achieve a much higher spatial resolution for temperature monitoring than any discrete sensor, generating a detailed panel temperature thermal map. Furthermore, this structure does not physically alter the existing display panel, is non-invasive, and incurs zero marginal hardware cost, fully reusing existing touch hardware resources. No independent temperature sensing elements or special materials are required on the display panel, and it has no impact on the module structure, thickness, or light transmittance, significantly reducing costs. In addition, the two- or three-stage cascaded circuitry ensures a high signal-to-noise ratio and signal integrity, and can detect weak coupled charge parameters at each point based on temperature changes, offering advantages in high accuracy and reliability. The temperature detection process only needs to be performed during the intervals of touch scanning or preset idle periods, and can measure and monitor the temperature parameter changes of the entire screen in real time at any time during the display module's factory use, providing strong support for real-time and effective adjustment of display parameters and the hardware environment based on temperature parameter changes.

[0069] Based on the same inventive concept, embodiments of this disclosure also provide a temperature detection method applied to the display module described above, wherein the display module further includes a processing unit, and the touch layer further includes a plurality of touch driving electrodes that are electrically isolated from and correspond one-to-one with the plurality of touch sensing electrodes. When performing temperature detection, the processing unit sends a sampling drive signal to the touch driving electrode, the touch sensing electrode generates a sensing charge based on the mutual capacitance between itself and the corresponding touch driving electrode, and the temperature detection circuit generates a first sampling voltage in response to the received sensing capacitance and amplifies the first sampling voltage to obtain a second sampling voltage. The processing unit acquires the second sampling voltage and determines the current temperature of the location based on the pre-stored relationship between the temperature at the location of the touch sensing electrode and the sampling voltage.

[0070] Those skilled in the art should understand that the specific process of the above method has been described in detail in the description of the temperature detection process of the display module above, and will not be repeated here.

[0071] The above driving method enables the generation of detailed panel temperature thermal maps using readily available touch electrodes distributed throughout the panel. This structure does not involve any physical alteration to the existing display panel, is non-invasive, and incurs zero marginal hardware cost. It fully reuses existing touch hardware resources, and eliminates the need for any independent temperature sensing elements or special materials on the display panel. It has no impact on the module structure, thickness, or light transmittance, significantly reducing costs. Furthermore, the two- or three-stage cascaded circuitry ensures a high signal-to-noise ratio and signal integrity, and can detect weak coupled charge parameters at each point based on temperature changes, offering advantages in high accuracy and reliability. The temperature detection process only needs to be performed during the intervals of touch scanning or preset idle periods, and can quickly and in real-time measure and monitor the temperature parameter changes of the entire screen at any time during the display module's factory use. This provides a strong guarantee for real-time and effective adjustment of display parameters and the hardware environment based on temperature parameter changes.

[0072] Based on the same inventive concept, embodiments of this disclosure also provide a display device, including the display module described in the above embodiments.

[0073] In this embodiment, the display device can be any product or component with display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, vehicle display, digital photo frame, or navigator. By using the above display module, it is possible to obtain the temperature distribution and temperature change of each point on the display panel in real time, grasp the display status, and adjust the display parameters in real time, thereby improving the user experience and having broad application prospects.

[0074] Obviously, the above embodiments of this disclosure are merely examples for clearly illustrating this disclosure, and are not intended to limit the implementation of this disclosure. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all implementation methods here. Any obvious variations or modifications derived from the technical solutions of this disclosure are still within the protection scope of this disclosure.

Claims

1. A display module, characterized in that, The display module includes a display panel, the display panel including: a touch layer disposed on a substrate, the touch layer including a plurality of touch sensing electrodes, and a temperature detection circuit including: A first sampling circuit is electrically connected to the plurality of touch sensing electrodes to receive sensing charges from the touch sensing electrodes and convert the sensing charges into a first sampling voltage. An amplification circuit amplifies the first sampling voltage to obtain a second sampling voltage, so that the display module can obtain the temperature of the corresponding point on the touch sensing electrode based on the second sampling voltage.

2. The display module according to claim 1, characterized in that, The first sampling circuit includes: a first operational amplifier, a first capacitor, and a first resistor. The inverting input of the first operational amplifier is electrically connected to the plurality of touch sensing electrodes, the non-inverting input is grounded, and the first capacitor and the first resistor are respectively connected across the inverting input and the output of the first operational amplifier.

3. The display module according to claim 2, characterized in that, The first operational amplifier is a transconductance operational amplifier.

4. The display module according to claim 1, characterized in that, The display panel further includes: a first insulating layer disposed on the surface of the film layer containing the touch sensing electrodes near the substrate, and a shielding layer of conductive material disposed on the surface of the first insulating layer near the substrate. The orthogonal projection range of the shielding layer on the substrate covers the orthogonal projection range of the plurality of touch sensing electrodes on the substrate. The temperature detection circuit further includes a buffer circuit, which is a follower circuit including a second operational amplifier. The non-inverting input of the second operational amplifier is electrically connected to the touch sensing electrode, the inverting input is electrically connected to the output of the second operational amplifier, and the output is electrically connected to the shielding layer.

5. The display module according to claim 2, characterized in that, The amplifier circuit includes a third operational amplifier, a second resistor, and a third resistor. The non-inverting input terminal of the third operational amplifier receives the first sampling voltage, and the inverting input terminal is electrically connected to the first terminal of the second resistor and the first terminal of the third resistor. The second terminal of the second resistor is grounded, and the second terminal of the third resistor is electrically connected to the output terminal of the third operational amplifier, which serves as the output terminal of the amplifier circuit.

6. The display module according to any one of claims 1-5, characterized in that, The temperature detection circuit further includes a low-pass filter circuit, which filters the received second sampling voltage and outputs a third sampling voltage.

7. The display module according to claim 6, characterized in that, The low-pass filter circuit includes: a fourth operational amplifier, a fourth resistor, a fifth resistor, a second capacitor, and a third capacitor. The fourth resistor and the fifth resistor are connected in series between the output terminal of the amplifier circuit and the non-inverting input terminal of the fourth operational amplifier. The first terminal of the second capacitor is electrically connected to the non-inverting input terminal of the fourth operational amplifier, and the second terminal is grounded. The first terminal of the third capacitor is electrically connected to the common connection terminal of the fourth resistor and the fifth resistor, and the second terminal is electrically connected to the output terminal of the fourth operational amplifier. The inverting input terminal of the fourth operational amplifier is electrically connected to the output terminal of the fourth operational amplifier, and this output terminal serves as the output terminal of the low-pass filter circuit.

8. The display module according to claim 5, characterized in that, The gain range of the amplifier circuit is greater than or equal to 50 and less than or equal to 200, and / or the resistance of the first resistor is greater than or equal to 50MΩ and less than or equal to 200MΩ, and the capacitance of the first capacitor is greater than or equal to 0.5pF and less than or equal to 2pF.

9. The display module according to claim 6, characterized in that, The touch layer also includes a plurality of touch driving electrodes that are electrically isolated and correspond one-to-one with the plurality of touch sensing electrodes. The cutoff frequency of the low-pass filter circuit is less than the Nyquist frequency, which is half the signal frequency of the sampling driving signal received by the touch driving electrode during temperature detection.

10. A display device, characterized in that, Includes the display module as described in claims 1-9.

11. A temperature detection method applied to a display module according to any one of claims 1-9, characterized in that, The display module further includes a processing unit, and the touch layer further includes a plurality of touch driving electrodes that are electrically isolated from and correspond one-to-one with the plurality of touch sensing electrodes. When performing temperature detection, the processing unit sends a sampling drive signal to the touch driving electrode, the touch sensing electrode generates a sensing charge based on the mutual capacitance between itself and the corresponding touch driving electrode, and the temperature detection circuit generates a first sampling voltage in response to the received sensing capacitance and amplifies the first sampling voltage to obtain a second sampling voltage. The processing unit acquires the second sampling voltage and determines the current temperature of the location based on the pre-stored relationship between the temperature at the location of the touch sensing electrode and the sampling voltage.

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