Temperature detection circuit, vehicle-mounted LCD display screen and vehicle

Abstract

The application discloses a temperature detection circuit, a vehicle-mounted LCD display screen and a vehicle. The temperature detection circuit is arranged in the vehicle-mounted LCD display screen and comprises a sampling resistor, a first end of the sampling resistor being connected with a voltage source, a second end of the sampling resistor being connected with a load of the vehicle-mounted LCD display screen, an amplifier, a positive-phase input end of the amplifier being connected with the first end of the sampling resistor, a negative-phase input end of the amplifier being connected with the second end of the sampling resistor, and the negative-phase input end being connected with an output end of the amplifier, and the amplifier being configured to output a voltage for representing an internal temperature of the vehicle-mounted LCD display screen. The above scheme does not need to add an additional temperature sensor and realizes internal temperature collection of the vehicle-mounted LCD display screen.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle-mounted LCD display screens, in particular to a temperature detection circuit, a vehicle-mounted LCD display screen and a vehicle. BACKGROUND

[0002] With the development of technology, more and more vehicles are installed with vehicle-mounted LCD display screens. The vehicle-mounted LCD display screen arranged on the instrument panel is used to display driving information such as vehicle speed, rotating speed, indicator light and fault light, the vehicle-mounted LCD display screen arranged on the center control contains information such as navigation, FM, voice interaction and video, and the vehicle-mounted LCD display screen arranged on the co-driver position contains information such as audio-visual entertainment. When the temperature inside the vehicle is very low (for example, lower than -20℃), the image of the vehicle-mounted LCD display screen will appear to be stuck, the picture will not be smooth, and even the screen will be black.

[0003] In the related art, in order to determine the current temperature of the vehicle-mounted LCD display screen, a temperature sensor is often added in the vehicle-mounted LCD display screen. However, the temperature sensor has the problems of high cost and general accuracy, thereby increasing the overall cost of the vehicle-mounted LCD display screen. CONTENT OF THE INVENTION

[0004] The present application provides a temperature detection circuit, a vehicle-mounted LCD display screen and a vehicle.

[0005] One of the technical solutions adopted by the present application is to provide a temperature detection circuit, which is arranged in a vehicle-mounted LCD display screen. The temperature detection circuit comprises:

[0006] a sampling resistor, a first end of the sampling resistor being connected with a voltage source, and a second end of the sampling resistor being connected with a load of the vehicle-mounted LCD display screen;

[0007] an amplifier, a positive input end of the amplifier being connected with the first end of the sampling resistor, a negative input end of the amplifier being connected with the second end of the sampling resistor, and the negative input end being connected with an output end of the amplifier, the amplifier being configured to output a voltage for representing an internal temperature of the vehicle-mounted LCD display screen.

[0008] Optionally, the temperature detection circuit further comprises a voltage dividing unit, a first end of the voltage dividing unit being connected with the first end of the sampling resistor, a second end of the voltage dividing unit being grounded, and a voltage dividing node of the voltage dividing unit being connected with the positive input end of the amplifier.

[0009] Optionally, the voltage dividing unit comprises a first resistor and a second resistor,

[0010] a first end of the first resistor being connected with the first end of the sampling resistor, and a second end of the first resistor being connected with the positive input end;

[0011] The first end of the second resistor is connected with the second end of the first resistor, and the second end of the second resistor is grounded.

[0012] Optionally, the resistance value of the sampling resistor is between 1mΩ and 30mΩ, and the resistance value of the second resistor is between 500kΩ and 1.5MΩ.

[0013] Optionally, the temperature detection circuit further comprises a third resistor,

[0014] The first end of the third resistor is connected with the negative phase input end, and the second end of the third resistor is connected with the second end of the sampling resistor.

[0015] Optionally, the negative phase input end is connected with the output end of the amplifier through a fourth resistor.

[0016] Another technical solution adopted by the present application is to provide a vehicle-mounted LCD display screen, which comprises the temperature detection circuit, the control component and the light source as described above.

[0017] The control component is connected with the output end of the amplifier and the light source respectively, and is configured to receive a voltage representing the internal temperature of the vehicle-mounted LCD display screen to adjust the brightness of the light source.

[0018] Optionally, the control component comprises a control unit and a backlight driving chip, the control unit is connected with the output end of the amplifier and the input end of the backlight driving chip respectively, and the backlight driving chip is connected with the light source.

[0019] Another technical solution adopted by the present application is to provide a vehicle, which comprises the vehicle-mounted LCD display screen as described above.

[0020] Optionally, the vehicle further comprises an intelligent cockpit system, which is connected with the vehicle-mounted LCD display screen through a serial bus.

[0021] The beneficial effects of the present application are as follows: the first end of the sampling resistor is connected with a voltage source, and the second end of the sampling resistor is connected with a load of the vehicle-mounted LCD display screen; the positive phase input end of the amplifier is connected with the first end of the sampling resistor, the negative phase input end of the amplifier is connected with the second end of the sampling resistor, the negative phase input end is connected with the output end of the amplifier, and the amplifier is configured to output a voltage representing the internal temperature of the vehicle-mounted LCD display screen. The temperature detection circuit adopted by the vehicle-mounted LCD display screen provided by the present application utilizes the corresponding relationship between the resistance value of the sampling resistor and the temperature, and can realize the internal temperature detection of the vehicle-mounted LCD display screen without adding an additional temperature sensor, thereby reducing the cost of the vehicle-mounted LCD display screen. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced. Obviously, the drawings in the following description only constitute some of the embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 is a structural schematic diagram of an embodiment of a temperature detection circuit provided by the present application;

[0024] Figure 2 is a structural schematic diagram of an embodiment of a vehicle-mounted LCD display provided by the present application;

[0025] Figure 3 is a structural schematic diagram of an embodiment of a vehicle provided by the present application;

[0026] Figure 4 is a structural schematic diagram of another embodiment of a vehicle provided by the present application. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely in the following description with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments only constitute some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] The terms "first", "second", and the like in the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed or can optionally include other steps or units inherent to the process, method or device.

[0029] In order to realize the internal temperature detection of the vehicle-mounted LCD display, in the related art, a temperature sensor is mainly added in the vehicle-mounted LCD display. It is found through research that the related temperature sensor has the disadvantages of high price and low precision.

[0030] The present application mainly designs a temperature detection circuit. Unlike the way of using a temperature sensor in the related art, the present application utilizes an amplifier to amplify the voltage drop of a sampling resistor according to the characteristic that the resistance of the sampling resistor is different at different temperatures, so as to obtain a voltage for representing the internal temperature of the vehicle-mounted LCD display.

[0031] For details, please refer to Figure 1 ,Figure 1 is a structural schematic diagram of an embodiment of the temperature detection circuit provided in the present application.

[0032] As shown in Figure 1 , the temperature detection circuit 10 provided in the present application is arranged in a vehicle-mounted LCD display screen, and the temperature detection circuit 10 can specifically include a sampling resistor Rs, an amplifier A, a voltage source U, and a load R L , wherein the load R L refers to the load of the vehicle-mounted LCD display screen.

[0033] The first end of the sampling resistor Rs is connected with the voltage source U, and the second end of the sampling resistor Rs is connected with the load R L .

[0034] In some possible implementations, the second end of the sampling resistor Rs is connected with the first end of the load R L , and the second end of the load R L is grounded.

[0035] The non-inverting input end of the amplifier A is connected with the first end of the sampling resistor Rs, the inverting input end of the amplifier A is connected with the second end of the sampling resistor Rs, the inverting input end is connected with the output end of the amplifier A, and the amplifier is configured to output a voltage Vout for representing the internal temperature of the vehicle-mounted LCD display screen.

[0036] In the embodiment of the present application, the resistance value of the sampling resistor Rs is related to the temperature of the LCD display screen.

[0037] More specifically, the lower the temperature of the LCD display screen, the greater the resistance value of the sampling resistor Rs, so as to increase the voltage drop across the sampling resistor, and in turn, the voltage Vout output by the amplifier is greater.

[0038] Similarly, the higher the temperature of the LCD display screen, the smaller the resistance value of the sampling resistor Rs, so as to decrease the voltage drop across the sampling resistor, and in turn, the voltage Vout output by the amplifier is smaller.

[0039] In some possible embodiments, by pre-acquiring the voltage Vout output by the amplifier at different temperatures of the vehicle-mounted LCD display screen, a correlation between the two can be established.

[0040] In some embodiments, the voltage value of the voltage source is 12V.

[0041] It can be understood that the voltage source is a direct current voltage source.

[0042] In some possible embodiments, the positive power pin of the amplifier A is connected with a 5V direct current voltage source, and the negative power pin of the amplifier A is connected with the second end of the load R L .

[0043] In some possible embodiments, the sampling resistor Rs is attached to the surface of the load R L .

[0044] In some embodiments, the temperature detection circuit further comprises a voltage dividing unit Rd, a first end of the voltage dividing unit Rd is connected to a first end of the sampling resistor Rs, a second end of the voltage dividing unit Rd is grounded, and a voltage dividing node of the voltage dividing unit Rd is connected to a non-inverting input terminal of the amplifier A.

[0045] In some embodiments, the voltage dividing unit Rd is in the form of a resistor.

[0046] In some embodiments, the voltage dividing unit Rd comprises a first resistor R1 and a second resistor R2.

[0047] The first end of the first resistor R1 is connected to the first end of the sampling resistor Rs, and the second end of the first resistor R1 is connected to the non-inverting input terminal of the amplifier A.

[0048] Further, the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is grounded.

[0049] In some embodiments, the sampling resistor Rs has a resistance value between 1 mΩ and 30 mΩ. Alternatively, the sampling resistor Rs has a resistance value between 5 mΩ and 20 mΩ. Alternatively, the sampling resistor Rs has a resistance value between 5 mΩ and 15 mΩ.

[0050] It should be noted that the sampling resistor Rs provided in the present application is not a temperature-sensitive resistor used in the related art. Since the sampling resistor Rs has a small resistance value, the voltage drop of the sampling resistor is amplified by the amplifier A, and the voltage Vout output by the amplifier A can be used to reflect the current temperature of the LCD display screen.

[0051] In some embodiments, the second resistor R2 has a resistance value between 500 kΩ and 1.5 MΩ. Alternatively, the second resistor R2 has a resistance value between 750 kΩ and 1.5 MΩ. Alternatively, the second resistor R2 has a resistance value between 750 kΩ and 1.2 MΩ. Exemplarily, the second resistor R2 has a resistance value of 1 MΩ.

[0052] The resistance value of the second resistor R2 is much larger than the resistance value of the first resistor R1.

[0053] In some embodiments, the first resistor R1 has a resistance value between 5 kΩ and 35 kΩ. Alternatively, the first resistor R1 has a resistance value between 15 kΩ and 30 kΩ. Exemplarily, the first resistor R1 has a resistance value of 20 kΩ.

[0054] In the embodiment, the amplifier A takes the ground level as the reference level, and the first resistor R1 is connected to the positive input terminal of the amplifier A as the current sensing resistor. In the related art, the main disadvantage of the low-side current sensing is that when the power supply ground and the load system ground are used, the voltage drop across the sampling resistor Rs will be different. If other circuits are based on the power supply ground, problems may occur. To maximize the avoidance of this problem, all circuits that interact should be based on the same ground, which helps to minimize the ground shift. Based on this, a second resistor R2 with a larger resistance value is added in the embodiment, so that the common mode input range of the amplifier A covers below 0, to reduce the ground shift.

[0055] In some embodiments, the temperature detection circuit further comprises a third resistor R3, a first end of the third resistor R3 is connected to the negative input terminal of the amplifier A, and a second end of the third resistor R3 is connected to the second end of the sampling resistor Rs.

[0056] In some embodiments, the first resistor R1 and the third resistor R3 have the same resistance value.

[0057] In some embodiments, the resistance value of the third resistor R3 is between 5kΩ-35kΩ. Alternatively, the resistance value of the third resistor R3 is between 15kΩ-30kΩ. Exemplarily, the resistance value of the third resistor R3 is 20kΩ.

[0058] In some embodiments, the negative input terminal of the amplifier A is connected to the output terminal of the amplifier A through a fourth resistor R4.

[0059] In some embodiments, the resistance value of the fourth resistor R4 is between 5kΩ-35kΩ. Alternatively, the resistance value of the fourth resistor R4 is between 15kΩ-30kΩ. Exemplarily, the resistance value of the fourth resistor R4 is 20kΩ.

[0060] In the above scheme, a first end of the sampling resistor is connected to a voltage source, and a second end of the sampling resistor is connected to a load of the vehicle-mounted LCD display screen; a positive input terminal of an amplifier is connected to the first end of the sampling resistor, a negative input terminal of the amplifier is connected to the second end of the sampling resistor, the negative input terminal is connected to an output terminal of the amplifier, and the amplifier is configured to output a voltage for representing an internal temperature of the vehicle-mounted LCD display screen. The temperature detection circuit provided by the present application for the vehicle-mounted LCD display screen utilizes the corresponding relationship between the resistance value of the sampling resistor and the temperature, and can realize internal temperature detection of the vehicle-mounted LCD display screen without adding an additional temperature sensor, thereby reducing the cost of the vehicle-mounted LCD display screen.

[0061] Please refer to Figure 2 , Figure 2 which is a structural schematic diagram of an embodiment of the vehicle-mounted LCD display screen provided by the present application.

[0062] AsFigure 2 As shown, the vehicle-mounted LCD display screen 20 comprises a temperature detection circuit 21, a control component 22 and a light source 23.

[0063] The temperature detection circuit 21 corresponds to the temperature detection circuit 10 described above.

[0064] The control component 22 is connected to the output end of the amplifier in the temperature detection circuit 21 and the light source 23, respectively.

[0065] The control component 22 is configured to receive a voltage representing the internal temperature of the vehicle-mounted LCD display screen to adjust the brightness of the light source 23.

[0066] In some embodiments, the light source 23 can be a plurality of LED backlight lamp beads.

[0067] For example, the light source 23 can include four groups of LED backlight lamp bead arrays connected in parallel, and each group of LED backlight lamp bead arrays includes nine LED backlight lamp beads connected in series.

[0068] In some application scenarios, the operating temperature of the vehicle-mounted LCD display screen is lower than -30℃, the image of the vehicle-mounted LCD display screen will appear to be stuck, the picture will not be smooth, and even a black screen phenomenon will occur, which cannot be displayed, affecting the driving safety.

[0069] In some related technologies, a resistance wire is installed in the vehicle-mounted LCD display screen to heat the vehicle-mounted LCD display screen by using the resistance wire.

[0070] In another related technology, a heating film is installed on the screen surface of the vehicle-mounted LCD display screen to heat the vehicle-mounted LCD display screen by heating the screen glass.

[0071] In the above related technologies, an additional heating module needs to be installed, which has the problem of complex design.

[0072] It should be noted that the higher the brightness of the light source 23, the faster the temperature of the LCD display screen 20 rises. In this embodiment, the brightness of the light source 23 is adjusted by the control component 22, so that the vehicle-mounted LCD display screen 20 is automatically heated without the need to install an additional heating device.

[0073] In some embodiments, the control component 22 includes a control unit 221 and a backlight driving chip 222, the control unit 221 is connected to the output end of the amplifier in the temperature detection circuit 21 and the input end of the backlight driving chip 222, respectively, and the backlight driving chip 222 is connected to the light source 23.

[0074] In some embodiments, the control unit 221 is connected to the output end of the amplifier through an I2C bus.

[0075] In some embodiments, the control unit 221 is connected with the input end of the backlight driving chip 222 through an I2C bus.

[0076] In some embodiments, the control unit 221 is an MCU (microcontroller unit).

[0077] In some embodiments, the backlight driving chip 222 adjusts the brightness of the light source by adjusting the duty cycle of PWM (pulse width modulation). For example, the greater the duty cycle, the higher the brightness of the light source.

[0078] In the above scheme, the first end of the sampling resistor is connected with the voltage source, and the second end of the sampling resistor is connected with the load of the vehicle-mounted LCD display screen; the non-inverting input end of the amplifier is connected with the first end of the sampling resistor, the inverting input end of the amplifier is connected with the second end of the sampling resistor, the inverting input end is connected with the output end of the amplifier, and the amplifier is configured to output a voltage for representing the internal temperature of the vehicle-mounted LCD display screen. The temperature detection circuit provided by the present application for the vehicle-mounted LCD display screen utilizes the corresponding relationship between the resistance value of the sampling resistor and the temperature, and without the need to additionally install a temperature sensor, the internal temperature detection of the vehicle-mounted LCD display screen can be realized, and the cost of the vehicle-mounted LCD display screen is reduced.

[0079] Please refer to Figure 3 , Figure 3 is a structural schematic diagram of an embodiment of the vehicle provided by the present application.

[0080] As Figure 3 shown, the vehicle 30 provided by the present application includes a vehicle-mounted LCD display screen 31. The vehicle-mounted LCD display screen 31 includes a temperature detection circuit 311, a control unit 312, a backlight driving chip 313, and a light source 314.

[0081] In some embodiments, the vehicle 30 further includes an intelligent cockpit system 32.

[0082] In some embodiments, the intelligent cockpit system 32 is connected with the control unit 312 through a CAN bus.

[0083] In some application scenarios, when the control unit 312 collects the output voltage V1 of the temperature detection circuit 311, it is considered that the external temperature of the vehicle-mounted LCD display screen 31 is -30℃, and the control unit 312 sends the real-time temperature to the intelligent cockpit host through the CAN bus.

[0084] Further, the control unit 312 sends the real-time temperature to the intelligent cockpit system 32 through the CAN bus, and the intelligent cockpit system 32 judges that the temperature of the LCD display screen is lower than -30℃ and lasts for 5S, decides to start the automatic temperature compensation function, and sends the control instruction back to the control unit 312 through the CAN bus.

[0085] Further, the control unit 312 receives the heating instruction, sets the PWM duty cycle of the backlight driving chip 313 to 100%, and generates heat through the light source 314 to quickly raise the temperature of the vehicle-mounted LCD display screen.

[0086] When the control unit 312 collects the output voltage of the temperature detection circuit 311 as V2, at this time, the intelligent cockpit system 32 considers that the external temperature is +10℃, when the intelligent cockpit system 32 receives the temperature > +10℃ and lasts for 10S, sends a heating-off instruction to the control unit 312.

[0087] After the control unit 312 receives the heating-off instruction, the brightness of the light source 314 is restored to the default brightness value through the backlight driving chip 313, and the automatic heating function of the vehicle-mounted LCD display screen is completed.

[0088] The above scheme, the first end of the sampling resistor is connected with the voltage source, the second end of the sampling resistor is connected with the load of the vehicle-mounted LCD display screen; the positive phase input end of the amplifier is connected with the first end of the sampling resistor, the negative phase input end of the amplifier is connected with the second end of the sampling resistor, the negative phase input end is connected with the output end of the amplifier, and the amplifier is configured to output the voltage for representing the internal temperature of the vehicle-mounted LCD display screen. The temperature detection circuit of the vehicle-mounted LCD display screen provided by the application utilizes the corresponding relationship between the resistance value of the sampling resistor and the temperature, without adding an additional temperature sensor, so that the internal temperature detection of the vehicle-mounted LCD display screen is realized, and the cost of the vehicle-mounted LCD display screen is reduced.

[0089] Please refer to Figure 4 , Figure 4 is a structural schematic diagram of another embodiment of the vehicle provided by the application.

[0090] As Figure 4 shown, the vehicle 40 provided by the application includes a vehicle-mounted LCD display screen 41 and an intelligent cockpit system 42, and the intelligent cockpit system 42 is connected with the vehicle-mounted LCD display screen 41 through a serial bus.

[0091] Specifically, the intelligent cockpit system 42 is connected with the vehicle-mounted LCD display screen 41 through a serdes (serializer and deserializer) to drive the display of related content.

[0092] The first end of the sampling resistor is connected with the voltage source, and the second end of the sampling resistor is connected with the load of the vehicle-mounted LCD display screen; the non-inverting input end of the amplifier is connected with the first end of the sampling resistor, the inverting input end of the amplifier is connected with the second end of the sampling resistor, the inverting input end is connected with the output end of the amplifier, and the amplifier is configured to output a voltage for representing the internal temperature of the vehicle-mounted LCD display screen. The temperature detection circuit provided by the application for the vehicle-mounted LCD display screen utilizes the corresponding relationship between the resistance value of the sampling resistor and the temperature, and without additional temperature sensors, the internal temperature detection of the vehicle-mounted LCD display screen can be realized, and the cost of the vehicle-mounted LCD display screen is reduced.

[0093] The above is only the embodiment of the application, and does not limit the patent scope of the application. The equivalent structure or equivalent flow transformation made by using the content of the specification and drawings of the application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A temperature detection circuit, characterized by comprising: The temperature detection circuit is arranged in a vehicle-mounted LCD display screen, and the temperature detection circuit comprises: a sampling resistor, a first end of the sampling resistor being connected with a voltage source, and a second end of the sampling resistor being connected with a load of the vehicle-mounted LCD display screen; an amplifier, a positive input end of the amplifier being connected with the first end of the sampling resistor, a negative input end of the amplifier being connected with the second end of the sampling resistor, and the negative input end being connected with an output end of the amplifier, the amplifier being configured to output a voltage for representing an internal temperature of the vehicle-mounted LCD display screen.

2. The temperature detection circuit according to claim 1, characterized by, The temperature detection circuit further comprises a voltage dividing unit, a first end of the voltage dividing unit being connected with the first end of the sampling resistor, a second end of the voltage dividing unit being grounded, and a voltage dividing node of the voltage dividing unit being connected with the positive input end of the amplifier.

3. The temperature detection circuit according to claim 2, wherein the voltage dividing unit comprises a first resistor and a second resistor, a first end of the first resistor being connected with the first end of the sampling resistor, and a second end of the first resistor being connected with the positive input end; a first end of the second resistor being connected with the second end of the first resistor, and a second end of the second resistor being grounded.

4. The temperature detection circuit according to claim 3, wherein a resistance value of the sampling resistor is between 1 mΩ and 30 mΩ, and a resistance value of the second resistor is between 500 kΩ and 1.5 MΩ.

5. The temperature detection circuit according to claim 1, wherein the temperature detection circuit further comprises a third resistor, a first end of the third resistor being connected with the negative input end, and a second end of the third resistor being connected with the second end of the sampling resistor.

6. The temperature detection circuit according to claim 1, wherein the negative input end is connected with the output end of the amplifier through a fourth resistor.

7. A vehicle-mounted LCD display screen, comprising: the temperature detection circuit according to any one of claims 1 to 6, a control component, and a light source; the control component being connected with the output end of the amplifier and the light source respectively, and the control component being configured to receive the voltage for representing the internal temperature of the vehicle-mounted LCD display screen to adjust a brightness of the light source.

8. The vehicle-mounted LCD display screen according to claim 7, wherein the control component comprises a control unit and a backlight driving chip, the control unit being connected with the output end of the amplifier and an input end of the backlight driving chip respectively, and the backlight driving chip being connected with the light source.

9. A vehicle characterized by comprising: The vehicle comprises the vehicle-mounted LCD display screen according to any one of claims 6 to 8.

10. The vehicle of claim 9, wherein, The vehicle further comprises an intelligent cockpit system, the intelligent cockpit system being connected with the vehicle-mounted LCD display screen through a serial bus.

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