IC chip, integrated circuit module and infrared distance measuring sensor

Abstract

The utility model relates to an IC chip, an integrated circuit module and an infrared distance measuring sensor, a circuit system of the IC chip comprises an optical signal output and input processing branch, and the optical signal output processing branch comprises an internal bias circuit, an oscillation circuit and an LED driving circuit which are connected in sequence; the internal bias circuit is composed of a constant current source circuit and a constant voltage source circuit, the internal bias circuit is connected with a power supply pin of the IC chip, and the power supply pin is externally connected with a power supply voltage VCC; the LED driving circuit is connected with an LED driving signal output pin of the IC chip, and the LED driving signal output pin outputs an LED driving signal for controlling an infrared transmitting tube outside the IC chip to work; the optical signal input processing branch comprises a pre-amplifier circuit, an automatic gain control amplification circuit, a band-pass filter circuit and a peak detection circuit which are connected in sequence; the photocurrent input port inputs photocurrent generated by a photodiode outside the IC chip. According to the utility model, optical signal output and input processing branches are integrated, the miniaturization design of the structure is realized, and the use cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of infrared distance measuring sensors, in particular to an IC chip, an integrated circuit module and an infrared distance measuring sensor. Background Art

[0002] Distance sensor, also called distance measuring sensor, is a kind of sensor, which is used to sense the distance between it and an object to complete a preset function, and has been widely used. According to the intelligent operation of all electronic devices, automatic distance detection sensors provide very convenient control capabilities, such as anti-collision distance measurement of mobile home appliances. Its application products include sweeping robots, automatic doors, automatic light switches, security equipment, etc.

[0003] The distance measurement principles adopted by existing distance measurement sensor products include: time of flight (TOF), phase shift measurement and triangulation. Among them, the triangulation method is a type of infrared distance measurement sensor, which uses a pair of infrared signal transmitting and receiving diodes, and uses the transmitting tube to emit a beam of infrared light. After irradiating the object to be measured, a reflection process is formed. The reflected infrared light is received by the receiving tube, and then the sensor calculates the distance between the sensor and the object to be measured based on the triangulation principle.

[0004] The existing infrared distance measurement sensor using triangulation method uses independently distributed transmitting tube IC and receiving tube IC, which makes the peripheral circuit design of the sensor complicated. In addition, the product is an optical sensor product, so it is very sensitive to interference light (indoor lighting, sunlight and other light), and is easily disturbed and cannot work properly. In addition, its measurement value (output value) is also very unstable and cannot be used for high-precision measurement. Utility Model Content

[0005] Based on the technical problems existing in the above infrared distance measuring sensor, the utility model provides an IC chip, an integrated circuit module and an infrared distance measuring sensor for the infrared distance measuring sensor.

[0006] To achieve the above object, the utility model provides an IC chip for an infrared ranging sensor, wherein the circuit system of the IC chip includes an optical signal output processing branch and an optical signal input processing branch, wherein:

[0007] The optical signal output processing branch includes an internal bias circuit, an oscillation circuit and an LED drive circuit connected in sequence; the internal bias circuit is composed of a constant current source and a constant voltage source circuit, the internal bias circuit is connected to the power pin of the IC chip, and the power pin is used to connect an external power supply voltage VCC; the LED drive circuit is connected to the LED drive signal output pin of the IC chip, and the LED drive signal output pin is used to output an LED drive signal for controlling the operation of an infrared emitting tube outside the IC chip;

[0008] The optical signal input processing branch includes a preamplifier circuit, an automatic gain control amplifier circuit, a bandpass filter circuit and a peak detection circuit which are connected in sequence; the preamplifier circuit is connected to a photocurrent input port on the IC chip, and the photocurrent input port is used to input a photocurrent generated by a photodiode outside the IC chip; the automatic gain control amplifier circuit is connected to an automatic gain control voltage pin of the IC chip; the output end of the peak detection circuit is provided with two paths, one of which is connected to an analog level output pin of the IC chip through an output level conversion circuit, and the other is connected to a digital level output pin of the IC chip through a comparator circuit and a Schmidt output circuit in sequence.

[0009] As a further preferred technical solution of the present utility model, the operating frequency of the oscillation circuit is 200KHz, and the center frequency of the bandpass filter circuit is 200KHz.

[0010] As a further preferred technical solution of the present invention, the voltage range of the power supply voltage VCC is 2.7-5.5V.

[0011] As a further preferred technical solution of the present utility model, the circuit system of the IC chip further includes an internal fusion circuit, and the internal fusion circuit is connected to the bandpass filter circuit.

[0012] As a further preferred technical solution of the utility model, the IC chip is also provided with a power on / off pin and a ground pin.

[0013] According to another aspect of the utility model, the utility model further provides an integrated circuit module, which includes an integrally packaged PD chip and the above-mentioned IC chip for the infrared ranging sensor, wherein the photodiode is provided on the PD chip.

[0014] According to another aspect of the utility model, the utility model also provides an infrared ranging sensor, characterized in that it includes the above-mentioned integrated circuit module, as well as a transmitting tube lens, a receiving tube lens and a PCB board, the integrated circuit module is electrically connected to the PCB board, the infrared transmitting tube is provided on the PCB board at the side of the integrated circuit module, the transmitting tube lens cover is provided on the infrared transmitting tube, and the receiving tube lens cover is provided on the photodiode in the integrated circuit module.

[0015] As a further preferred technical solution of the utility model, the infrared ranging sensor also includes a shell, the shell has two independent and mutually light-shielded installation cavities, the infrared transmitting tube and the integrated circuit module are respectively arranged in the two installation cavities, each of the installation cavities is provided with a light-transmitting hole, the transmitting tube lens is installed in the light-transmitting hole corresponding to the infrared transmitting tube, and the receiving tube lens is installed in the light-transmitting hole corresponding to the integrated circuit module.

[0016] As a further preferred technical solution of the utility model, the integrated circuit module and the infrared emitting tube are fixedly arranged on one side of the PCB board, and the other side of the PCB board is provided with passive components and connectors.

[0017] Compared with the prior art, the IC chip, integrated circuit module and infrared distance measuring sensor of the utility model can achieve the following beneficial effects:

[0018] 1) The IC chip of the utility model integrates the optical signal output processing branch and the optical signal input processing branch, which not only realizes the miniaturized structure design and reduces the use cost; but also facilitates the simplification of the user's peripheral circuit design and is more convenient to use;

[0019] 2) The IC chip of the utility model is applied to infrared ranging, so that it is not affected by ambient light (such as sunlight, LED lighting light), can transmit modulated light signals and receive modulated light signals, and the signals between the transmitted signal and the received signal are synchronized, and the received signal is correct. Even if DC light or other light is input, it will not react. The IC chip only works under modulated light, so it has strong anti-interference performance;

[0020] 2) The IC chip of this utility model has a built-in automatic gain control amplifier circuit, which is easy for users to adjust through external control voltage. When the modulation frequency deviates, the center frequency of the bandpass filter can be adjusted to the same sensitivity through internal fusion. This will have a very strong advantage, meaning that the signal deviation between the emitted infrared light and the received infrared light in the user's application is very small.

[0021] 4) The integrated circuit module of the utility model adopts a two-in-one package of the PD chip and the IC chip, which further simplifies the module application circuit, improves the stability and anti-interference performance, and the cost of module production is low and the assembly process is simpler.

[0022] 5) The infrared distance measuring sensor of the utility model performs high-precision distance measurement based on the triangulation method. It adopts a two-in-one packaged integrated circuit module, which solves the technical problems of folk interference light and peripheral frequency noise. It works with modulated light 200KHz and is not interfered by peripheral light signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Figure 1 The utility model is a circuit system block diagram of an IC chip used for an infrared ranging sensor.

[0025] Figure 2 The utility model is a schematic diagram of the structure of the infrared distance measuring sensor.

[0026] In the figure: 1. Shell, 2. PCB board, 3. Infrared transmitting tube, 4. Transmitting tube lens, 5. Integrated circuit module, 6. Receiving tube lens.

[0027] The purpose, features and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. The terms such as "upper", "lower", "left", "right", "middle" and "one" used in the preferred embodiments are only used to facilitate the description, and are not used to limit the scope of the implementation of the present invention. The changes or adjustments in their relative relationships shall also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0029] like Figure 1 As shown, the embodiment of the utility model provides an IC chip for an infrared ranging sensor, wherein the circuit system of the IC chip includes an optical signal output processing branch and an optical signal input processing branch, wherein the optical signal output processing branch is used to transmit a modulated optical signal, and the optical signal input processing branch is used to receive a modulated optical signal.

[0030] The optical signal output processing branch includes an internal bias circuit, an oscillation circuit and an LED drive circuit connected in sequence; the internal bias circuit is composed of a circuit of a constant current source and a constant voltage source, the internal bias circuit is connected to a power pin of the IC chip, and the power pin is used to connect an external power supply voltage VCC; the LED drive circuit is connected to an LED drive signal output pin of the IC chip, and the LED drive signal output pin is used to output an LED drive signal for controlling the operation of the infrared emitting tube 3 outside the IC chip;

[0031] The optical signal input processing branch includes a preamplifier circuit, an automatic gain control amplifier circuit, a bandpass filter circuit and a peak detection circuit which are connected in sequence; the preamplifier circuit is connected to a photocurrent input port on the IC chip, and the photocurrent input port is used to input a photocurrent generated by a photodiode outside the IC chip; the automatic gain control amplifier circuit is connected to an automatic gain control voltage pin of the IC chip; the output end of the peak detection circuit is provided with two paths, one of which is connected to an analog level output pin of the IC chip through an output level conversion circuit, and the other is connected to a digital level output pin of the IC chip through a comparator circuit and a Schmidt output circuit in sequence.

[0032] In the above structure:

[0033] Internal bias circuit: It is composed of constant current source and constant voltage source circuits to achieve the input of a wide range of power supply voltage VCC of 2.7-5.5v, and provide constant current and constant voltage for the oscillation circuit. The internal bias circuit is a common power supply, which provides constant current and constant voltage for the optical signal input processing branch of the chip, and also keeps the output value of the bandpass filter circuit (BPF) constant, that is, it is independent of the VCC input voltage, and the constant output ensures the stable operation of the bandpass filter function.

[0034] Oscillation circuit: It is a circuit with precise frequency oscillation, and its operating frequency is 200KHz.

[0035] LED driving circuit: The input frequency of 200KHz is output through the internal constant current circuit, and the output current is 2mA, so that the overall power consumption of the IC is minimized, and only a small power signal is output to drive the infrared emitting tube 3; specifically, the output signal: 200KHz, Duty 25%, IO Current: 2mA.

[0036] Preamplifier circuit: converts the photocurrent of the external input photodiode into a voltage (I / V) signal. The structure uses a fixed gain amplifier so that it is not affected by external noise or other environments.

[0037] Automatic gain control amplifier circuit: Its function is to reduce the amplification deviation of the IC itself and the deviation in the secondary application (actual application after packaging) by externally adjusting the gain of the amplifier, so that it can be adjusted externally according to the user's specifications.

[0038] Bandpass filter circuit: The center frequency is filtered within the range of 200KHz + / - 40KHz. The center frequency is adjusted through the connected internal fusion circuit to achieve the calibration function of the IC itself. It is synchronized with the LED modulation frequency of the Fusing standard, and the frequency range is within + / - 40KHz.

[0039] Peak detection circuit: A circuit for high-speed peak detection that outputs the peak level of the final bandpass filter circuit output signal. In order to ensure the dynamic range, the offset voltage of the bandpass filter circuit output is about 0.7volts. As the light intensity increases, the output signal becomes larger upward, and it does not matter if it is saturated downward. That is, the peak level detector outputs by detecting the high value of the bandpass filter output signal. When responding to instantaneous noise, since there is a possibility of malfunction, it is necessary to include a function that can suppress the instantaneous peak value, and it must be output almost at a DC value, so it is very important to set the correction value.

[0040] Output level conversion circuit: The peak value of the voltage is the offset voltage of the bandpass filter output, which is 0.7 volts, so it is 0.7-2.6 volts (Vref = 2.7 volts standard). This value is linked to VCC and changed to Rail-to-RailLevel in proportion to the final output.

[0041] Comparator circuit: It is composed of a differential amplifier and receives the signal detected in the peak detection and compares it. The comparator output is generated by the size of the "+" input voltage and the "-" input voltage. When the "+" input voltage and the "-" input voltage are similar, when the voltage fluctuates due to noise, etc., the comparator output will continue to repeat HIGH and LOW. Therefore, it can be designed to have a hysteresis output characteristic. By giving it a hysteresis output characteristic through a built-in Schmitt output circuit, the comparator output will not be affected by noise.

[0042] Specifically, the IC chip is also provided with an off / on pin and a ground pin, wherein the off / on pin is used to adjust the switching time of the IC chip, which can reduce unnecessary power consumption and adjust the operation time according to the user's intention.

[0043] An embodiment of the utility model provides an integrated circuit module, including an integrally packaged PD chip and the above-mentioned IC chip for infrared ranging sensor, wherein the photodiode is provided on the PD chip, and the photocurrent generated by the photodiode after receiving the light signal is output to the photocurrent input port of the IC chip.

[0044] like Figure 2 As shown, the embodiment of the utility model provides an infrared distance measuring sensor, which includes an integrated circuit module 5, a transmitting tube lens 4, a receiving tube lens 6, a PCB board 2 and an infrared transmitting tube 3. The integrated circuit module 5 and the infrared transmitting tube 3 are arranged on the left and right and are electrically connected to the PCB board 2 respectively. The transmitting tube lens 4 is covered on the infrared transmitting tube 3, and the receiving tube lens 6 is covered on the photodiode in the integrated circuit module 5. The light signal output processing branch of the IC chip generates an LED driving signal to drive the infrared transmitting tube 3 to work so as to generate infrared light to irradiate the object to be measured through the transmitting tube lens 4, and the infrared light reflected by the object to be measured is irradiated to the photodiode through the receiving tube lens 6. The photodiode generates a photocurrent and outputs it to the light signal input processing branch of the IC chip for processing. The processed signal is connected to the PCB board 2 via the digital level output pin or the analog level output pin.

[0045] Specifically, the PCB board 2 is arranged in a protective shell 1, and the shell 1 has two independent installation cavities that are shielded from light from each other. The infrared transmitting tube 3 and the integrated circuit module 5 are respectively arranged in the two installation cavities, and each of the installation cavities is provided with a light-transmitting hole. The transmitting tube lens 4 is installed in the light-transmitting hole corresponding to the infrared transmitting tube 3, and the receiving tube lens 6 is installed in the light-transmitting hole corresponding to the integrated circuit module 5.

[0046] Specifically, the integrated circuit module 5 and the infrared emitting tube 3 are fixedly arranged on one side of the PCB board 2, and the other side of the PCB board 2 is provided with passive components and connectors, wherein the passive components are capacitors, resistors, field effect transistors, etc.; the connector is a pin socket, such as a 4-pin socket, which is used to connect the PCB board 2 with external devices for signal connection.

[0047] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.

Claims

1. An IC chip for an infrared ranging sensor, characterized in that: The circuit system of the IC chip includes an optical signal output processing branch and an optical signal input processing branch, wherein: The optical signal output processing branch includes an internal bias circuit, an oscillation circuit and an LED drive circuit connected in sequence; the internal bias circuit is composed of a constant current source and a constant voltage source circuit, the internal bias circuit is connected to the power pin of the IC chip, and the power pin is used to connect an external power supply voltage VCC; the LED drive circuit is connected to the LED drive signal output pin of the IC chip, and the LED drive signal output pin is used to output an LED drive signal for controlling the operation of an infrared emitting tube outside the IC chip; The optical signal input processing branch includes a preamplifier circuit, an automatic gain control amplifier circuit, a bandpass filter circuit and a peak detection circuit which are connected in sequence; the preamplifier circuit is connected to a photocurrent input port on the IC chip, and the photocurrent input port is used to input a photocurrent generated by a photodiode outside the IC chip; the automatic gain control amplifier circuit is connected to an automatic gain control voltage pin of the IC chip; the output end of the peak detection circuit is provided with two paths, one of which is connected to an analog level output pin of the IC chip through an output level conversion circuit, and the other is connected to a digital level output pin of the IC chip through a comparator circuit and a Schmidt output circuit in sequence.

2. The IC chip for infrared ranging sensor according to claim 1, characterized in that: The operating frequency of the oscillation circuit is 200 KHz, and the center frequency of the bandpass filter circuit is 200 KHz.

3. The IC chip for infrared ranging sensor according to claim 1, characterized in that: The voltage range of the power supply voltage VCC is 2.7-5.5V.

4. The IC chip for infrared ranging sensor according to claim 1, characterized in that: The circuit system of the IC chip further includes an internal fusion circuit, and the internal fusion circuit is connected to the bandpass filter circuit.

5. The IC chip for infrared ranging sensor according to any one of claims 1 to 4, characterized in that: The IC chip is also provided with an on / off pin and a ground pin.

6. An integrated circuit module, characterized in that: It comprises an integrally packaged PD chip and the IC chip for the infrared ranging sensor according to any one of claims 1 to 5, wherein the photodiode is arranged on the PD chip.

7. An infrared ranging sensor, characterized in that: It comprises the integrated circuit module as claimed in claim 6, as well as a transmitting tube lens, a receiving tube lens and a PCB board, wherein the integrated circuit module is electrically connected to the PCB board, the infrared transmitting tube is provided on the PCB board at the side of the integrated circuit module, the transmitting tube lens cover is provided on the infrared transmitting tube, and the receiving tube lens cover is provided on the photodiode in the integrated circuit module.

8. The infrared ranging sensor according to claim 7, characterized in that: It also includes a shell, which has two independent installation cavities that are shielded from light from each other. The infrared transmitting tube and the integrated circuit module are respectively arranged in the two installation cavities. Each of the installation cavities is provided with a light-transmitting hole. The transmitting tube lens is installed in the light-transmitting hole corresponding to the infrared transmitting tube, and the receiving tube lens is installed in the light-transmitting hole corresponding to the integrated circuit module.

9. The infrared ranging sensor according to claim 7, characterized in that: The integrated circuit module and the infrared emitting tube are both fixedly arranged on one side of the PCB board, and the other side of the PCB board is provided with passive components and connectors.

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