CN108446033A - Projecting apparatus handwriting equipment - Google Patents

Abstract

The invention discloses a handwriting device for a projector, comprising: an infrared matrix, and the infrared matrix includes: a plurality of infrared transmitting tubes, a group of infrared transmitting circuit boards, a plurality of infrared receiving tubes, a group of infrared receiving circuit boards and a control module , a plurality of infrared sending tubes are electrically connected to the infrared sending circuit board, a plurality of infrared receiving tubes are electrically connected to the infrared receiving circuit board, the infrared sending circuit board and the infrared receiving circuit board are arranged one by one, and the infrared sending tube is used to complete the infrared emission , the infrared receiving tube is used to complete the receiving of infrared rays, the infrared receiving circuit board communicates with the control module through the I ² C bus protocol; and the U-shaped fixing piece and strap; the handwriting device disclosed in the present invention can be fixed on a projector or a computer display through a clip On the screen, the assembly is flexible, easy to use, and it is energy-saving and environmentally friendly, preventing chalk dust from flying.

Description

projector handwriting device

technical field

The present invention relates to the technical field of display devices, and more specifically relates to a projector handwriting device.

Background technique

The way of displaying PPT (presentation) through a projector has been widely used in teaching, lectures and work reports. Compared with ordinary blackboard display, PPT can display pictures and tables conveniently, and can teach without using chalk and dust-free; on the other hand, because the projector displays light on a white cloth, it can slow down Problems caused by poor lighting or reflections and poor angles.

However, teachers generally need to mark and supplement the PPT during the teaching process. The traditional method is to use the pen tool that comes with the PPT and cooperate with the left mouse button to click and slide. The operation process is cumbersome and expensive capacitive touch screens are used. It will increase the cost of colleges and universities; and the existing infrared matrix has a low resolution and cannot be used by teachers.

Therefore, how to provide a handwriting device with a projector that is easy to use, small in size and high in resolution is an urgent problem to be solved by those skilled in the art.

Contents of the invention

In view of this, the present invention provides a projector handwriting device, which is small in size and easy to use, and can be displayed on the projector only by handwriting in the matrix.

In order to achieve the above object, the present invention adopts the following technical solutions:

A projector handwriting device, comprising:

Infrared ray matrix, the infrared ray matrix includes: a plurality of infrared ray sending tubes, a group of infrared ray sending circuit boards, a plurality of infrared ray receiving tubes, a group of infrared ray receiving circuit boards and a control module, a plurality of the infrared ray sending tubes are connected with the infrared ray The sending circuit board is electrically connected, and a plurality of the infrared receiving tubes are electrically connected to the infrared receiving circuit board, and the infrared sending circuit board is arranged opposite to the infrared receiving circuit board one by one, and the infrared sending tube is used to complete the infrared For transmitting, the infrared receiving tube is used to complete the receiving of infrared rays, and the infrared receiving circuit board communicates with the control module through the I ² C bus protocol;

The U-shaped fixing part, the U-shaped fixing part includes a first U-shaped fixing part and a second U-shaped fixing part, the opening direction of the first U-shaped fixing part is opposite to the opening direction of the second U-shaped fixing part, and the The first U-shaped fixture includes a first connection section, a second connection section and a third connection section, the second U-shaped fixture includes a fourth connection section, a fifth connection section and a sixth connection section, and the infrared sending The circuit board is located inside the first U-shaped fixture, and the bolts pass through the first connecting section close to the opening end of the first U-shaped fixture, the infrared sending circuit board and the third connecting section to connect them Fixed connection; the infrared receiving circuit board is located inside the second U-shaped fixing, and the bolts pass through the fourth connecting section close to the opening end of the second U-shaped fixing, the infrared sending circuit board and the sixth connection section to fix it;

A strap, the strap is located on one side of the infrared matrix, and is used to fix the infrared matrix on the computer display screen.

The advantage of using this device is: two rows of infrared emitting circuit boards and infrared receiving circuit boards form an infrared matrix. When in use, the infrared matrix is fixed on the computer display screen through the strap, and the length can be adjusted according to the actual computer display screen size. The display is combined into an infrared touch screen. The infrared emitting tube on one side emits infrared rays, and the infrared receiving tube on the other side judges whether the infrared rays are received by judging whether the emitted infrared rays are blocked by objects. When the infrared rays are received, the infrared receiving tube generates low power If it is blocked by an object, the infrared receiving tube will generate a high level. The A/D converter is connected to the infrared receiving tube. By detecting the voltage value of each infrared receiving tube, it is judged whether there is an object touching the infrared matrix. Finally, it is converted with the A/D The device communicates with the MCU microcontroller through the I ² C bus to filter the data, calculate the coordinate value, and send the coordinate value to the host computer through the serial port UART.

Preferably, a converging hole is provided at the position where the second connecting section is in close contact with the plurality of infrared transmitting tubes, and the diameter of the converging hole is 1.5 mm; A convergent hole is opened at the position of close contact, and the diameter of the convergent hole is 1.5 mm. Adding converging holes can play a role in converging infrared rays, reducing divergence, enhancing point-to-point "communication", and improving anti-interference ability.

Preferably, the plurality of infrared sending tubes or the plurality of infrared receiving tubes are arranged at equal intervals, and the arrangement pitch is 4mm. The resolution of the infrared matrix can be effectively improved by setting the distribution spacing of the infrared emitting tubes or the infrared receiving tubes and matching the vertical arrangement to complete the welding.

Preferably, the control module includes:

MCU microcontroller, a capacitor C10 is connected in series between the 14 pin and the 15 pin of the MCU microcontroller, and the 14 pin is connected to the positive pole of the power supply, and the 15 pin is grounded;

A USB-to-serial port unit, the MCU microcontroller is connected to the USB-to-serial port unit through a serial input and output interface;

A voltage conversion unit, the USB-to-serial port unit is connected to the voltage conversion unit through a USB interface;

The power supply selection and program download unit, the power line interface in the voltage conversion unit is connected to the input interface of the power supply selection and program download unit.

Preferably, the USB-to-serial port unit includes:

USB-to-serial port chip, 1 pin of the USB-to-serial port chip is grounded and connected to one end of capacitor C8 at the same time, and the other end of the capacitor C8 is connected to 16 pins and connected to the positive pole of the power supply; 2 pins of the USB-to-serial port chip are connected The switch tube D1 is connected in series, and the switch tube D1 is sequentially connected in series with the first light-emitting diode DS2, the first resistor R4, the second resistor R3 and one end of the second light-emitting diode DS3, and one end of the second light-emitting diode DS3 is connected to 4 pins; the crystal oscillator Y1 is connected in series between pins 7 and 8 of the USB-to-serial chip, capacitors C6 and C7 are connected in parallel at both ends of the crystal oscillator Y1, a wire is drawn between capacitors C6 and C7 to ground, and 16 pins The pin is connected to the positive pole of the power supply.

Preferably, the voltage conversion unit includes:

USB port, pin 1 and pin 5 of the USB port are connected in parallel with the first polarity capacitor C1, the first polarity capacitor C1 is connected in parallel with the first capacitor C2, and pins 2 and 3 are connected with the USB converter The 5-pin and 6-pin connection of the serial port chip;

A voltage regulator, one end of the first capacitor C2 is connected to the input terminal of the voltage regulator, the GND terminal of the voltage regulator is grounded, the two output terminals of the voltage regulator are connected and lead wires are connected to the first The bipolar capacitor C3 is connected, and the anode of the second polar capacitor C3 is connected to 3.3V and connected in parallel with the second capacitor C4.

Preferably, the power supply selection and program download unit includes:

Pin header, pin 1 of the pin header is connected to the 5V input terminal, pin 2 is connected to one end of the double-pole double-throw switch, and pin 3 is connected to the 3.3V input terminal;

A download button, the other end of the double-pole double-throw switch is connected to one end of the download button, and a signal line is drawn to connect the collector of the triode Q1, the emitter of the triode Q1 is connected to the photodiode DS1, the first pull-down Resistor R16 and the second pull-down resistor R17, a signal line is drawn between the first pull-down resistor R16 and the second pull-down resistor R17 to ground, and a signal line is drawn between the base of the triode Q1 and the pull-down resistor R16 A signal line is connected to the other end of the download button, and a signal line is drawn between the collector of the triode Q1 and the photodiode DS1 to connect to the positive pole of the power supply.

Preferably, the infrared sending circuit board includes:

A single row of pins, the positive pole of the infrared sending tube is 1 pin of the single row of pins, and 2 pins of the single row of pins are grounded;

A current limiting resistor, the negative electrode of the infrared sending tube is connected to one end of the current limiting resistor, and the other end of the current limiting resistor R is grounded. The current-limiting resistor is often connected in series in the circuit to limit the current of the branch circuit, so as to prevent the components connected in series from being burned out due to excessive current. At the same time, the current-limiting resistor can also act as a voltage divider.

Preferably, the infrared receiving circuit board includes:

A/D converter, the 9 pins of the A/D converter are grounded, the 10 pins and 11 pins are suspended, the 12 pins are grounded, the 14 pins of the A/D converter are connected in series with resistor R12, and the 15 pins are connected to the ground. Pin series resistance R13, and the two ends of the resistance R12 and R13 are connected to the positive pole of the power supply at the same time, the 13-pin and 16-pin are both connected to the positive pole of the power supply, and the 14-pin and 15-pin are connected to the I ² C of the MCU microcontroller interface connection;

The analog input pin of the A/D converter reads the voltage value of the infrared receiving tube and converts it into a digital quantity, communicates with the MCU microcontroller through the SCL and SDA pins, and the 10 pins and 11 pins use the chip The internal reference voltage is not connected, and pins 12 and 13 are I ² C address setting pins, which can form four addresses of 00, 01, 10 and 11, that is, a pair of SCL and SDA can control four A/D converters.

Pull-down resistors R14-R21, one end of the infrared receiving tube is connected to a 3.3V voltage drop, the other end is connected to a pull-down resistor, and a signal line is drawn between the infrared receiving tube and the pull-down resistor to connect to the A/D converter Analog input pins 1-8. The pull-down resistor clamps the uncertain signal at low level through a resistor to ensure that the detection pin of the A/D converter has a high level output.

Preferably, a client is also included, and the client is used for receiving and analyzing the coordinates uploaded by the MCU microcontroller and displaying the handwritten results.

It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a projector handwriting device, which is fixed on the computer display screen by clips or magnets, easy to install and flexible to assemble, and the infrared matrix is small in size and economical. Affordable, you only need to write pictures by hand in the matrix and then display them on the projector; reduce the frequency of blackboard teaching, avoid flying chalk dust, and teachers don't have to turn around to write on the blackboard frequently.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention, and those skilled in the art can also obtain other drawings according to the provided drawings without creative work.

Accompanying drawing of Fig. 1 is the structural representation of projector handwriting equipment of the present invention;

Fig. 2 accompanying drawing is the first U-shaped fixture structural representation of projector handwriting equipment of the present invention;

Fig. 3 accompanying drawing is the second U-shaped fixture structural representation of projector handwriting equipment of the present invention;

Accompanying drawing of Fig. 4 is the MCU microcontroller circuit principle diagram of projector handwriting equipment of the present invention;

Fig. 5 accompanying drawing is the schematic diagram of the infrared transmission circuit of projector handwriting equipment of the present invention;

Fig. 6 accompanying drawing is the schematic diagram of the infrared receiving circuit of projector handwriting equipment of the present invention;

Fig. 7 accompanying drawing is the USB transfer serial port circuit principle diagram of projector handwriting equipment of the present invention;

Fig. 8 accompanying drawing is the 5V-3.3V circuit schematic diagram of projector handwriting equipment of the present invention;

Fig. 9 accompanying drawing is the 5/3.3V power supply selection and program downloading circuit principle diagram of projector handwriting equipment of the present invention;

In Figures 1-9:

1-infrared matrix, 11-infrared sending tube, 12-infrared sending circuit board, 13-infrared receiving tube, 14-infrared receiving circuit board, 2-U-shaped fixing piece, 21-the first U-shaped fixing piece, 22-the first Two U-shaped fixtures, 211-first connecting section, 212-second connecting section, 213-third connecting section, 221-fourth connecting section, 222-fifth connecting section, 223-sixth connecting section, 23- First bolt, 24-second bolt 25-converging hole, 3-strap.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

Referring to accompanying drawing 1-accompanying drawing 8, embodiment 1 of the present invention discloses a kind of projector handwriting equipment, comprises:

Infrared ray matrix 1, infrared ray matrix 1 comprises: a plurality of infrared ray sending tubes 11, a group of infrared ray sending circuit boards 12, a plurality of infrared ray receiving tubes 13, a group of infrared ray receiving circuit boards 14 and a control module 15, and a plurality of infrared ray sending tubes 11 are It is electrically connected with the infrared sending circuit board 12, and a plurality of infrared receiving tubes 13 are electrically connected with the infrared receiving circuit board 14, and the infrared sending circuit board 12 and the infrared receiving circuit board 14 are arranged one by one oppositely, and the infrared sending tube 11 is used for completing the emission of infrared rays , the infrared receiving tube 13 is used to complete the receiving of infrared rays, and the infrared receiving circuit board 14 communicates with the control module 15 through the I ² C bus protocol;

The U-shaped fixture 2, the U-shaped fixture 2 includes a first U-shaped fixture 2 and a second U-shaped fixture 22, the first U-shaped fixture 21 is opposite to the opening direction of the second U-shaped fixture 22, and the first U-shaped fixture 22 is relatively open. The U-shaped fixing part 21 includes a first connecting section 211, a second connecting section 212 and a third connecting section 213, and the second U-shaped fixing part 22 includes a fourth connecting section 221, a fifth connecting section 222 and a sixth connecting section 223, The infrared sending circuit board 12 is located inside the first U-shaped fixing part 21, and the first bolt 23 passes through the first connecting section 211 close to the opening end of the first U-shaped fixing part 21, the infrared sending circuit board 12 and the third connecting section (213 ) is fixedly connected; the infrared receiving circuit board 14 is located inside the second U-shaped fixing part 22, and the second bolt 24 passes through the fourth connecting section 221 close to the opening end of the second U-shaped fixing part 22, the infrared sending circuit board 14 and the The sixth connection section 223 is fixedly connected;

The strap 3, the strap 3 is located on one side of the infrared matrix 1.

In some embodiments, the infrared transmitting tube 11 or the infrared receiving tube 13 are transparent transmitting tubes and receiving tubes with a round head and a border of 3 mm in diameter with a scattering angle of 30°, a wavelength of 940 nm, and a diameter of 3 mm.

In some embodiments, the U-shaped fixture 2 can be made of opaque acrylic.

Specifically, the position where the second connecting section 212 is in close contact with a plurality of infrared sending tubes 11 is provided with a converging hole (25), and the diameter of the converging hole 25 is 1.5 mm; the fifth connecting section 222 is in close contact with a plurality of infrared receiving tubes 13 A converging hole 25 is provided at the position where the converging hole 25 has a diameter of 1.5mm.

Specifically, a plurality of infrared sending tubes 11 or a plurality of infrared receiving tubes 13 are arranged at equal intervals, and the arrangement pitch is 4 mm.

Specifically, the control module 15 includes:

MCU microcontroller, the capacitor C10 is connected in series between pin 14 and pin 15 of the MCU microcontroller, and pin 14 is connected to the positive pole of the power supply, and pin 15 is grounded;

USB-to-serial port unit, the MCU microcontroller is connected to the USB-to-serial port unit through the serial input and output interface;

The voltage conversion unit, the USB-to-serial port unit is connected to the voltage conversion unit through the USB interface;

The power supply selection and program download unit, the power line interface in the voltage conversion unit is connected to the input interface of the power supply selection and program download unit.

In some embodiments, the MCU microcontroller is a single-chip microcomputer of the STC15 series whose model is IAP15FW4K61S2.

Specifically, the USB-to-serial port unit includes:

USB-to-serial port chip, the 1 pin of the USB-to-serial port chip is grounded and connected to one end of the capacitor C8 at the same time, the other end of the capacitor C8 is connected to the 16-pin and connected to the positive pole of the power supply; the 2 pins of the USB-to-serial port chip are connected in series to the switch tube D1, The switch tube D1 is sequentially connected in series with the first light-emitting diode DS2, the first resistor R4, the second resistor R3 and one end of the second light-emitting diode DS3, and one end of the second light-emitting diode DS3 is connected to pin 4; The crystal oscillator Y1 is connected in series between pin 8 and pin 8, capacitors C6 and C7 are connected in parallel at both ends of crystal oscillator Y1, a wire is drawn between capacitors C6 and C7 to ground, and pin 16 is connected to the positive pole of the power supply.

In some embodiments, the USB-to-serial port chip uses a CH340G USB bus adapter chip, the resistance values of R3 and R4 can be 1k, D1 uses a high-speed switching diode of model 1N4148, and the capacity of capacitors C6 and C7 can be 33pF.

Specifically, the voltage conversion unit includes:

USB port, pin 1 and pin 5 of the USB port are connected in parallel with the first polarity capacitor C1, the first polarity capacitor C1 is connected in parallel with the first capacitor C2, pins 2 and 3 are connected with pin 5 of the USB-to-serial chip and 6-pin connection;

Voltage regulator, one end of the first capacitor C2 is connected to the input terminal of the voltage regulator, the GND terminal of the voltage regulator is grounded, the two output terminals of the voltage regulator are connected and the lead wire is connected to the second polarity capacitor C3, the second polarity The anode of the neutral capacitor C3 is connected to 3.3V and connected in parallel with the second capacitor C4.

In some embodiments, the model of the regulator is AMS1117-3.3V regulator, and the capacitance of C1 and C3 can be 4.7 μF.

Specifically, the power supply selection and program download unit includes:

Pin row, pin 1 of the pin header is connected to the 5V input terminal, pin 2 is connected to one end of the double-pole double-throw switch, and pin 3 is connected to the 3.3V input terminal;

Download button, the other end of the double-pole double-throw switch is connected to one end of the download button, and a signal line is drawn to connect the collector of the transistor Q1, and the emitter of the transistor Q1 is connected to the photodiode DS1, the first pull-down resistor R16 and the second pull-down in turn Resistor R17, a signal line is drawn between the first pull-down resistor R16 and the second pull-down resistor R17 to ground, and a signal line is drawn between the base of the transistor Q1 and the pull-down resistor R16 to connect to the other end of the download button. A signal line is drawn between the collector and the photodiode DS1 to connect to the positive pole of the power supply.

In some embodiments, the transistor Q1 is an NPN diode,

Specifically, the infrared sending circuit board 22 includes:

Single-row needle holder, pin 1 of the positive pole single-row needle holder of the infrared sending tube 11, and grounding of 2-pin of the single-row needle holder;

A current-limiting resistor, the negative pole of the infrared sending tube 11 is connected to one end of the current-limiting resistor, and the other end of the current-limiting resistor R is grounded.

In some embodiments, the resistance of the current limiting resistor may be 100Ω.

Specifically, the infrared receiving circuit board 24 includes:

A/D converter, 9 pins of A/D converter are grounded, 10 pins and 11 pins are suspended, 12 pins are grounded, 14 pins of A/D converter are connected in series resistor R12, 15 pins are connected in series with resistor R13 , and both ends of the resistors R12 and R13 are connected to the positive pole of the power supply at the same time, both pins 13 and 16 are connected to the positive pole of the power supply, and pins 14 and 15 are connected to the I ² C interface of the MCU microcontroller;

Pull-down resistors R14-R21, one end of the infrared receiving tube 23 is connected to a 3.3V voltage drop, the other end is connected to a pull-down resistor, and a signal line is drawn between the infrared receiving tube and the pull-down resistor to connect to the analog input terminal 1- of the A/D converter 8 pins.

In some embodiments, the A/D converter is an A/D converter with 8 channels and the model is ADS7830, and the resistance value of the pull-down resistors R14-R21 can be 1k.

Specifically, it also includes a client, which is used to receive and analyze the coordinates uploaded by the MCU microcontroller and display the handwritten results.

When the projector handwriting device disclosed in the embodiment of the present invention is in use, two rows of infrared tubes are arranged on the computer display screen to form an infrared matrix, and the infrared matrix emits infrared rays through the infrared emission tubes fixed on one side of the computer display screen by the strap. The infrared receiving tube on the other side judges whether the infrared ray is received, so as to judge whether the emitted infrared ray is blocked by the object. If the infrared ray is received, the infrared receiving tube will generate a low level, and if it is blocked by the object, the infrared receiving tube will generate a high level. 8 The 8-bit analog quantity is converted into a digital quantity. The AD chip ADS7830 is connected to 8 infrared receiving tubes. By detecting the voltage value of each infrared receiving tube, it is judged whether there is an object touching the infrared matrix. Finally, the MCU microcontroller IAP15W4K61S2, which communicates with ADS7830 through the I ² C bus, filters the data, calculates the coordinate value, and sends the coordinate value to the client through the serial port UART, and displays the actual line drawing result.

Example 2

Taking a 14-inch display as an example, the size is 312.1mm*175.6mm, which is rounded up to 320mm*176mm.

In Example 2 of the present invention, the diameter of the infrared pair tube is 3 mm, the scattering angle of the infrared pair tube is 30°, the thickness of the emitting tube is 5.4 mm, and the thickness of the receiving tube is 2.7 mm.

The calculation formula of scattering angle and interference distance is: interference radius R=interference distance L*sin(scattering angle/2);

Before installing the convergence hole, the interference radius R=176.0mm*sin15°=45.6mm;

After installing the converging hole, the scattering angle θ=arctan(0.75/5.4)=7.9°, the interference radius R=176.0*sin7.9°=24.2mm. It can be seen that the converging hole can play a certain anti-interference ability.

Example 3

Taking the 14-inch display screen as an example, the size is 312.1mm*175.6mm, which is rounded up to 320mm*176mm, and the existing PCB circuit board solder joints cause the infrared tube to occupy a width of 5.08mm.

The calculation formula of the resolution is: (display length L*display width)/infrared tube width;

According to the situation of the above PCB board, the resolution is only 63*35, and the resolution is low at this time;

In order to improve the resolution, Embodiment 3 of the present invention improves the design of the traditional PCB board, the design distribution spacing is 4mm, and the welding is completed in a vertical arrangement. At this time, the resolution is 80*44, and the resolution is significantly improved.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for the related information, please refer to the description of the method part.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. a kind of projecting apparatus handwriting equipment, which is characterized in that including：

Infrared ray matrix (1), the infrared ray matrix (1) include：Multiple infrared ray sending tubes (11), one group of infrared ray send electricity Road plate (12), multiple infrared receiver tubes (13), one group of infrared radiation receiving circuit plate (14) and control module (15), it is multiple described Infrared ray sending tube (11) is electrically connected with the infrared transmitter circuit plate (12), multiple infrared receiver tubes (13) with Infrared radiation receiving circuit plate (14) electrical connection, the infrared transmitter circuit plate (12) and the infrared radiation receiving circuit plate (14) it is oppositely arranged one by one, the infrared ray sending tube (11) is used to complete the transmitting of infrared ray, the infrared receiver tube (13) it is used to complete the reception of infrared ray, the infrared radiation receiving circuit plate (14) passes through I²C bus protocols and the control mould Block (15) communication connection；

U-shaped fixing piece (2), the U-shaped fixing piece (2) include the first U-shaped fixing piece (21) and the second U-shaped fixing piece (22), institute It is opposite with the described second U-shaped opening direction of fixing piece (22) to state the first U-shaped fixing piece (21), the first U-shaped fixing piece (21) include the first linkage section (211), the second linkage section (212) and third linkage section (213), the second U-shaped fixing piece (22) include the 4th linkage section (221), the 5th linkage section (222) and the 6th linkage section (223), the infrared transmitter circuit plate (12) it is internal to be located at the described first U-shaped fixing piece (21), the first bolt (23) sequentially passes through close described first U-shaped fixing piece (21) first linkage section (211), the infrared transmitter circuit plate (12) and the third linkage section (213) of open end Be fixed connection；The infrared radiation receiving circuit plate (14) is located at the described second U-shaped fixing piece (22) inside, the second bolt (24) the 4th linkage section (221) close to the described second U-shaped fixing piece (22) open end, infrared ray hair are sequentially passed through Circuit board (14) and the 6th linkage section (223) is sent to be fixed connection；

Shoulder strap (3), the shoulder strap (3) are located at the side of the infrared ray matrix (1).

2. a kind of projecting apparatus handwriting equipment according to claim 1, it is characterised in that：Second linkage section (212) with The position that the multiple infrared ray sending tube (11) is in close contact offers convergence hole (25), described to restrain a diameter of of hole (25) 1.5mm；

The position that 5th linkage section (222) is in close contact with the multiple infrared receiver tube (13) offers convergence hole (25), a diameter of 1.5mm of convergence hole (25).

3. a kind of projecting apparatus handwriting equipment according to claim 1, which is characterized in that the multiple infrared ray sending tube (11) it is equidistantly arranged between, arrangement spacing is 4mm；

It is equidistantly arranged between multiple infrared receiver tubes (13), arrangement spacing is 4mm.

4. a kind of projecting apparatus handwriting equipment according to claim 1, it is characterised in that：The control module (15) includes：

MCU microcontrollers, series capacitance C10 between 14 pins and 15 pins of the MCU microcontrollers, and 14 pin connects Positive pole, the 15 pin ground connection；

USB turns serial port unit, and the MCU microcontrollers turn serial port unit with the USB by serial input-output interface (SIO) and connect；

Voltage conversion unit, the USB turn serial port unit and are connect with the voltage conversion unit by USB interface；

Power supply selects and program download unit, and the electric source line interface in the voltage conversion unit is selected with the power supply and program The input interface of download unit connects.

5. a kind of projecting apparatus handwriting equipment according to claim 4, which is characterized in that the USB turns serial port unit and includes：

USB turns serial port chip, and the 1 pin ground connection that the USB turns serial port chip connect with one end of capacitance C8 simultaneously, the capacitance The C8 other ends connect with 16 pins and connect positive pole；The USB turns 2 pin serial connection connecting valve pipe D1 of serial port chip, The switching tube D1 is sequentially connected in series the first Light-Emitting Diode DS2, first resistor R4, second resistance R3 and the second light-emitting diodes One end of one end of pipe DS3, the second light emitting diode DS3 connects 4 pins；The USB turns 7 pins and 8 of serial port chip Connect the both ends crystal oscillator Y1, the crystal oscillator Y1 shunt capacitance C6 and C7 between pin, and a conducting wire is drawn between capacitance C6 and C7 and is connect Ground, 16 pins connect positive pole.

6. a kind of projecting apparatus handwriting equipment according to claim 4 or 5, which is characterized in that the voltage conversion unit packet It includes：

USB port, 1 pin of the USB port and 5 the first polar capacitor of pins in parallel C1, the first polar capacitor C1 with First power input connects, and the first polar capacitor C1 is in parallel with the first capacitance C2,2 pins and 3 pins and the USB Turn 5 pins and the connection of 6 pins of serial port chip；

One end of voltage-stablizer, the first capacitance C2 connects the input terminal of the voltage-stablizer, the GND terminations of the voltage-stablizer Two output ends on ground, the voltage-stablizer are connected and extraction wire is connect with the second polar capacitor C3, second polar capacitor C3 connect with second source input terminal and is connected in parallel with the second capacitance C4.

7. a kind of projecting apparatus handwriting equipment according to claim 4, which is characterized in that the power supply selection and program are downloaded Unit includes：

Needle is arranged, 1 pin of row's needle connects power input one, and 2 pins connect one end of double-point double-throw switch, the connection of 3 pins Power input two；

Button is downloaded, the other end of the double-point double-throw switch connects described one end for downloading button, and draws a signal line The emitter of the collector of connecting triode Q1, the triode Q1 is sequentially connected photodiode DS1, the first pull down resistor R16 and the second pull down resistor R17 draws a signal line between the first pull down resistor R16 and the second pull down resistor R17 Ground connection is drawn the signal line connection download and is pressed between the base stage of the triode Q1 and the pull down resistor R16 The other end of key, between the collector and the photodiode DS1 of the triode Q1 drawing a signal line connects power supply Anode.

8. a kind of projecting apparatus handwriting equipment according to claim 1, which is characterized in that the infrared transmitter circuit plate (22) include：

The anode of single needle stand, the infrared ray sending tube (11) connects 1 pin of the single needle stand, the single needle stand 2 pins are grounded；

The cathode of current-limiting resistance, the infrared ray sending tube (11) connects one end of the current-limiting resistance, and the current-limiting resistance R The other end ground connection.

9. a kind of projecting apparatus handwriting equipment according to claim 1, which is characterized in that the infrared radiation receiving circuit plate (24) include：

A/D converter, the 9 pins ground connection of the A/D converter, 10 pins and 11 pins are hanging, 12 pins ground connection, the A/D Electricity is accessed in 14 pin serial connection resistance R12,15 pin serial connection resistance R13, and the resistance R12 of converter and the both ends R13 simultaneously Source anode, 13 pins and 16 pins are all connected with positive pole, the I of 14 pins and 15 pins and the MCU microcontrollers²C interface Connection；

Pull down resistor R14-R21, a termination positive pole of the infrared receiver tube (13), the other end connect pull down resistor, And the analog input end 1-8 that signal wire accesses the A/D converter is drawn between the infrared receiver tube and pull down resistor Pin.

10. according to a kind of projecting apparatus handwriting equipment of claim 1-9 any one of them, which is characterized in that further include having client End, the client are used to receive and parse through the coordinate that the MCU microcontrollers upload and show hand-written result.