Static resistance detection device applied to ink-jet printer

Abstract

An anti-static performance detection device applied to an ink-jet printer belongs to the technical field of detection equipment, and comprises a test box body, an electrostatic generator, a humidity sensor, a humidity monitoring circuit, an electrostatic tolerance monitoring circuit, a temperature monitoring circuit and a humidity simulation mechanism, the humidity simulation mechanism comprises a heating tank, an electric heating plate, a temperature switch, an electromagnetic valve, a humidity sensor, a humidity monitoring circuit and an electrostatic tolerance monitoring circuit which are mounted together, the temperature monitoring circuit is mounted in an element box, and the element box and an electrostatic generator are mounted in the test box body. The electrostatic tolerance monitoring circuit can be arranged in different air humidity environments and different electrostatic intensities, static electricity absorbed by the shell of the ink-jet printer is detected, and when the static electricity shielding effect of the shell is lower than a threshold value in the detection process, the electrostatic tolerance monitoring circuit can prompt measuring personnel in time, so that the situation that the ink-jet printer is damaged due to too large static electricity is prevented. According to the invention, a technical support is provided for a manufacturer to ensure the product quality and a use terminal to normally use the ink-jet printer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of printer performance testing equipment, and particularly relates to a static resistance performance detection device applied to an inkjet printer. BACKGROUND

[0002] The inkjet printer is a device that sprays ink in the form of tiny droplets onto paper to form text or pictures, and the inkjet printer adopts two main technologies, namely, a thermal bubble type and a micro piezoelectric type. When the thermal bubble type inkjet printer works, under program control, a micro heating element rapidly heats ink input from an ink cartridge to form a bubble, the bubble expands to push the ink out of a nozzle to form an ink droplet, when the bubble disappears, the ink in the nozzle is reabsorbed for the next spraying, and the above process is continuously repeated to print the required text or picture on the paper. The thermal bubble type inkjet printer has the advantages of high printing speed and low cost, but the ink is prone to chemical change under high temperature, which will affect the printing quality to a certain extent. When the micro piezoelectric type inkjet printer works, under program control, a piezoelectric element controls the ink input from an ink cartridge to be sprayed through a nozzle under the action of voltage, the piezoelectric element shrinks and extends under signal control to accurately control the shape and flight direction of the ink droplet, and then the required text or picture is printed on the paper. The micro piezoelectric type inkjet printer has the advantages of high printing quality and no chemical change of the ink due to heating, but has the disadvantage of high cost and is not suitable for high-speed printing.

[0003] When the inkjet printer is working, static electricity has a great influence on the inkjet printer, mainly in the following aspects: (1) static electricity can make the ink unevenly distributed in the jetting process, resulting in color stripes and uneven color on the printed product, because static electricity can generate electric charges near the nozzle, and the repulsive force between like charges can cause the ink to separate and gather, thereby affecting the uniformity of the jet; (2) static electricity can make the surface of the paper charged, increasing the adsorption of the ink on the paper, resulting in the ink staying on the paper for too long, and the ink marks on the printed product; (3) static electricity can cause dust and other small impurities to accumulate inside the print head, which can block the nozzle, affect the printing quality, and even damage the nozzle; (4) static electricity can damage sensitive circuit components, causing equipment failure or performance degradation; (5) static electricity can interfere with the ink during the jetting process, causing uneven atomization of the ink, resulting in ink flying phenomenon, affecting the printing quality and possibly contaminating the inside of the printer; (6) static electricity can cause the printing medium (such as paper, cloth, etc.) to stick together during transmission, causing printing misalignment or paper jam; (7) static electricity attracts dust and other particles, making the surface of the printed product not clean, reducing the product quality. Due to the above reasons, the static shielding effect of the inkjet printer shell on the surrounding related equipment directly affects the printing quality of the inkjet printer. There is no suitable device for detecting the static shielding effect of the inkjet printer shell in the prior art, so the production quality of the inkjet printer and the use of the inkjet printer will be adversely affected to some extent. SUMMARY

[0004] In order to overcome the disadvantages in the prior art that there is no suitable device for detecting the static shielding effect of the inkjet printer shell, which adversely affects the production quality of the inkjet printer and the use of the inkjet printer, the present application provides a static resistance performance detection device for inkjet printers, which can be conveniently set in different air humidity environments and different intensity static electricity under the joint action of related agencies, and can detect the static electricity absorbing (i.e. shielding) performance of the shell of the inkjet printer. When the shielding effect of the shell is lower than the threshold value, the measurement personnel can be prompted in time to prevent the inkjet printer from being damaged due to excessive static electricity, thereby ensuring the product quality for the production manufacturer and providing strong technical support for the normal use of the inkjet printer by the end user.

[0005] The technical solution adopted by the technical solution of the present application is:

[0006] An electrostatic discharge (ESD) resistance testing device for inkjet printers includes a test chamber, an ESD generator, and a humidity sensor. It also includes a humidity monitoring circuit, an ESD resistance monitoring circuit, a temperature monitoring circuit, and a humidity simulation mechanism. The upper part of the test chamber is an open structure, and the test chamber is equipped with a movable cover, one side of which is hinged to the test chamber. The ESD generator is installed inside the test chamber on one side. The humidity simulation mechanism includes a heating tank, an electric heating plate, a temperature switch, and a solenoid valve. A mounting shell is installed at the lower end of the heating tank, the electric heating plate is fixedly installed inside the heating shell, the temperature switch is fixedly installed at the outer end of the heating tank, and an air outlet is installed at the upper end of the heating tank. The test chamber includes a water inlet pipe with a sealing cap at the top, an outlet pipe connected to the bottom of a solenoid valve, an inlet pipe fixed to the top of the solenoid valve, and a heating tank filled with water via the water inlet pipe. The humidity sensor, humidity monitoring circuit, electrostatic withstand monitoring circuit, and temperature monitoring circuit are housed in a component box, which is fixedly installed on the other side of the test chamber. The signal output terminal of the humidity sensor is electrically connected to the signal input terminal of the humidity monitoring circuit, the power output terminal of the humidity monitoring circuit is electrically connected to the power input terminal of the solenoid valve, and the power output terminal of the temperature monitoring circuit is electrically connected to the power input terminal of the electric heating plate.

[0007] Furthermore, a lower support magnet plate is fixedly installed at the upper end of the test chamber, and an upper support magnet plate is fixedly installed at the lower end of the movable cover. The lower end of the upper support magnet plate and the upper end of the lower support magnet plate are attracted together, and a one-way air valve is installed on the upper outside of the movable cover.

[0008] Furthermore, the solenoid valve is a normally open solenoid valve with a spool.

[0009] Furthermore, the humidity monitoring circuit includes an adjustable resistor, a resistor, and a transistor that are electrically connected. One end of the adjustable resistor is connected to one end of the first resistor and one end of the second resistor. The other end of the second resistor is connected to the base of the transistor, and the other end of the first resistor is connected to the emitter of the transistor.

[0010] Furthermore, the electrostatic discharge (ESD) tolerance monitoring circuit includes an electrically connected metal plate, a transistor, a capacitor, an alarm, and a field-effect transistor (FET), and is equipped with a vacuum chuck. The metal plate is fixedly installed inside the chuck, and the metal plate is connected to the gate of the FET. The drain of the FET is connected to the base of the first transistor and one end of an adjustable resistor. The other end of the adjustable resistor is connected to the collector of the first transistor and the positive power input terminal of the alarm. The emitter of the first transistor is connected to the positive terminal of the capacitor and the base of the second transistor. The collector of the second transistor is connected to the negative power input terminal of the alarm. The negative terminal of the capacitor is connected to the emitter of the second transistor and the source of the FET.

[0011] Furthermore, the temperature monitoring circuit is a relay, with the positive power input terminal of the relay connected to one end of the temperature switch.

[0012] Furthermore, a vent valve is installed at the upper end of the heating tank.

[0013] Compared with existing technologies, the beneficial effects of this invention are: This invention is suitable for use by manufacturers and repair departments. With the joint action of relevant institutions, it can conveniently detect the static electricity absorption (i.e., static electricity shielding) of the inkjet printer casing under different air humidity environments and different static electricity intensities using an electrostatic generator, humidity monitoring circuit, and humidity simulation mechanism. During the detection, when the static electricity shielding effect of the casing is lower than the threshold, the electrostatic tolerance monitoring circuit can promptly alert the measuring personnel, preventing damage to the inkjet printer due to excessive static electricity. This invention provides strong technical support for manufacturers to ensure product quality and for end users to use inkjet printers normally. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention;

[0015] Figure 2 This is the circuit diagram of the present invention. Detailed Implementation

[0016] Figures 1-2As shown, an anti-static performance testing device for inkjet printers includes a power module A1, a test chamber 1, an electrostatic generator A, and a humidity sensor A2. It also includes a humidity monitoring circuit 2, an electrostatic tolerance monitoring circuit 3, a temperature monitoring circuit 4, and a humidity simulation mechanism. The upper end of the test chamber 1 has an open structure, and the test chamber is equipped with a movable cover 101, the rear end of which is hinged to the upper rear end of the test chamber 1. The electrostatic generator A is fixedly installed in the left part of the test chamber (the adjustment handle of the electrostatic generator A is located at the front outer end of the test chamber 1). The humidity simulation mechanism includes a heating tank 51, an electric heating plate RT, a temperature switch W, and a solenoid valve DC. A hollow mounting shell 52 is sealed and welded to the lower end of the heating tank 51. The electric heating plate RT is insulated and fixedly installed inside the heating shell 52, with its heating surface in close contact with the lower outer end of the heating tank 51. On the side, the temperature switch W is fixedly installed on the upper part of the heating tank 51, and the temperature sensing surface of the temperature switch W is in close contact with the upper part of the heating tank 51. A gas outlet pipe 53 and a water inlet pipe 54 that communicate with its interior are welded to the middle part of the upper end and the left part of the heating tank 51, respectively. A sealing cap 541 is installed on the upper end of the water inlet pipe 54 by thread. The upper end of the gas outlet pipe 53 is connected to the lower end of the solenoid valve DC by thread. An air inlet pipe 55 is installed on the upper end of the solenoid valve DC by thread. The upper left side of the air inlet pipe 55 is welded to the upper right end of the test chamber 1 and communicates with the interior of the test chamber 1. Water is added to the heating tank 51 through the water inlet pipe 54. The power module A1, humidity sensor A2 (the probe is located outside the opening at the left end of the component box 6), humidity monitoring circuit 2, electrostatic withstand monitoring circuit 3, and temperature monitoring circuit 4 are installed on the circuit board inside the component box 6. The component box 6 is fixedly installed on the right side inside the test chamber 1.

[0017] Figures 1-2As shown, a rectangular hollow lower support magnet plate 102 is glued to the upper perimeter of the test chamber 1. An upper support magnet plate 103 is glued to the lower end of the movable cover 101. The lower end of the upper support magnet plate 103 and the upper end of the lower support magnet plate 102 are sealed and attracted together. A one-way air valve 104 is installed on the upper part of the middle of the movable cover. The solenoid valve DC is a normally open valve core solenoid valve. The humidity monitoring circuit includes an adjustable resistor RP1, resistors R1 and R2, and a transistor Q1 connected via circuit board wiring. One end of the adjustable resistor RP1 is connected to one end of the first resistor R1 and one end of the second resistor R2. The other end of the second resistor R2 is connected to the base of the transistor Q1. The other end of the first resistor R1 is connected to the emitter of the transistor Q1. The electrostatic discharge (ESD) withstand monitoring circuit includes a detection copper plate M, transistors Q3 and Q4, capacitor C1, alarm B, and field-effect transistor Q2 connected by wires, and is equipped with a rubber vacuum chuck 31. The copper plate M is glued and fixed to the lower end of the chuck 31. The wires connected to the copper plate M are led upward through an opening in the middle of the upper end of the chuck 31 (the opening is sealed with sealant). The copper plate M and the gate of the field-effect transistor Q2 are connected (the chuck 31 is located on the outer end of the component box 6). The drain of transistor 2 is connected to the base of the first transistor Q3 and one end of the adjustable resistor RP2. The other end of the adjustable resistor RP2 is connected to the collector of the first transistor Q3 and the positive power input terminal of the alarm B. The emitter of the first transistor Q3 is connected to the positive terminal of capacitor C1 and the base of the second transistor Q4. The collector of the second transistor Q4 is connected to the negative power input terminal of the alarm B. The negative terminal of capacitor C1 and the emitter of the second transistor Q4 are connected to the source of the field-effect transistor Q2. The temperature monitoring circuit is a relay J1, and the positive power input terminal of relay J1 is connected to one end of the temperature switch W. A vent valve 8 is installed on the upper end of the heating tank 51 (to release overpressure gas in the heating tank). Figure 2In this circuit, power module A1 is a finished product of AC 220V to DC 12V power module; electric heating plate RT is a finished product of PTC electric heating plate with working voltage AC 220V and power of 500W; relay J1 is model DC 12V; temperature switch W is a finished product of normally closed contact snap-action temperature switch model KSD301 (controlling temperature 100℃); transistors Q1, Q3, and Q4 are model 9013 (NPN); field effect transistor Q2 is model 3DJ6; solenoid valve DC is a finished product of normally closed valve core solenoid valve with power of 2W; alarm B is a finished product of active continuous audible alarm model FM12V; capacitor C1 is model 470μF / 25V (filtering function); humidity sensor A2 is a finished product of humidity transmitter model KS-SHTE, which has two power input terminals and one signal output terminal. The larger the detected humidity signal, the larger the voltage signal output terminal, and vice versa; electrostatic generator A is model HC-120KV. The adjustable high-voltage electrostatic generator; the adjustable resistor RP1 has a resistance of 100K (adjusted to 10K in this embodiment). When the resistance of the adjustable resistor RP1 is relatively large, its voltage drop is large, so the solenoid valve DC will be energized when the humidity inside the test chamber is relatively high. That is, the humidity value of this invention is set relatively high. When the resistance of the adjustable resistor RP1 is relatively small, its voltage drop is small, so the solenoid valve DC will be energized when the humidity inside the test chamber is relatively low. That is, the humidity value of this invention is set relatively low. The adjustable resistor RP2 has a resistance of 470K (adjusted to 47K in this embodiment). When the resistance of the adjustable resistor RP2 is relatively large, its voltage drop is large, so the buzzer B will be energized when the electrostatic value inside the test chamber is relatively high. That is, the electrostatic value of this invention is set relatively large. When the resistance of the adjustable resistor RP2 is relatively small, its voltage drop is small, so the buzzer B will be energized when the electrostatic value inside the test chamber is relatively low. That is, the electrostatic value of this invention is set relatively low.

[0018] Figures 1-2As shown, the power input pins 1 and 2 of the power module A1, the power input pins 1 and 2 of the electrostatic generator A (the discharge terminal of the electrostatic generator A is located on the right outer side of its housing), the two control power input terminals of the relay J1 of the temperature monitoring circuit, and the two poles of the AC 220V power supply are connected by wires. The power output terminals 3 and 4 of power module A1, the power input terminals 1 and 2 of humidity sensor A2, the emitter of transistor Q1 (power input terminal of humidity monitoring circuit), the collector of transistor Q3 (power input terminal of electrostatic withstand monitoring circuit) and the negative terminal of capacitor C1, the other end of temperature switch W (power input terminal of temperature monitoring circuit) and the negative terminal of relay J1 are connected by wires. The signal output terminal 3 of humidity sensor A2 and the other end of adjustable resistor RP1 (signal input terminal of humidity monitoring circuit) are connected by wires. The collector of transistor Q1 (power output terminal of humidity monitoring circuit), the 3rd pin of power module A1 and the two ends of power input of solenoid valve DC are connected by wires. The two normally open contacts of relay J1 (power output terminal of temperature monitoring circuit) and the two ends of power input of electric heating plate RT are connected by wires.

[0019] Figures 1-2As shown, before testing, the movable cover 101 is opened, and the inkjet printer 7 is placed inside the test chamber 1 (the operator attaches the rubber vacuum suction cup 3 to the housing of the inkjet printer 7, and the lower end of the copper sheet M is attached to the upper end of the housing of the inkjet printer 7). Then, the movable cover 101 is closed, and the main power switch is turned on. The power module A1 and the electrostatic generator A (the testing personnel can adjust the adjustment handle of the electrostatic generator A according to the testing needs to adjust the output voltage of the electrostatic generator A) are powered on and start working. The electrostatic generator A generates static electricity that is conducted into the test chamber 1. After the power module A1 is powered on, its pins 3 and 4 output a stable DC 12V power supply, which enters the power input terminals of the humidity sensor A2, the humidity monitoring circuit, the electrostatic tolerance monitoring circuit, and the temperature monitoring circuit. The above circuits and sensors are powered on and start working. When the water temperature in heating tank 51 is below 100℃, the internal contacts of temperature switch W close, thus energizing relay J1 and closing its control power input terminal and normally open contact terminal. The electric heating plate RT is energized and heats the water in heating tank 51. When the water temperature in heating tank 51 is above 100℃, the internal contacts of temperature switch W open, thus de-energizing relay J1 and opening its control power input terminal and normally open contact terminal. The electric heating plate RT is no longer energized and heats up. Through the above, the present invention can continuously keep the water in heating tank 51 heated. After the water evaporates, the valve core opened by solenoid valve DC enters the test chamber 1. When the humidity inside test chamber 1 is lower than the value set by adjustable resistor RP1, the voltage signal output from pin 3 of humidity sensor A2 is relatively low. This voltage signal is divided by adjustable resistor RP1 and resistor R1, and then reduced by resistor R2 to limit the current, resulting in a voltage below 0.7V at the base of transistor Q1. Transistor Q1 will not conduct, and the solenoid valve DC will not be energized. The humid air evaporated in the heating tank continues to enter test chamber 1 (excess air is discharged to the outside through the one-way valve). When the humidity inside test chamber 1 is higher than the value set by adjustable resistor RP1, the voltage signal output from pin 3 of humidity sensor A2 is relatively high. This voltage signal is divided by adjustable resistor RP1 and resistor R1, and then reduced by resistor R2 to limit the current, resulting in a voltage above 0.7V at the base of transistor Q1. Transistor Q1 will conduct, and its collector outputs a low level, which enters the negative power input terminal of solenoid valve DC. The solenoid valve DC will then be energized, its valve core will close, and the humid air evaporated in the heating tank will no longer enter test chamber 1. Through the above, the present invention can control the humidity value inside the test chamber 1 to a set value and detect the static electricity absorbed by the inkjet printer casing (that is, the static electricity shielding).

[0020] Figures 1-2As shown, when the humidity inside the test chamber 1 is within the set range and the static pressure value is set, and the electrostatic shielding effect of the inkjet printer 7 is good, the static voltage signal detected by the copper plate M is relatively small. The field-effect transistor Q2 is in a zero-bias state, and the resistance between its drain and source is small. The voltage drop between the field-effect transistor Q2 and the adjustable resistor RP2 is small. Thus, the 12V power supply enters the base of the transistor Q3 through the voltage drop between the field-effect transistor Q2 and the adjustable resistor RP2, which is lower than 0.7V. The transistor Q3 is cut off, and the emitter does not output a high level. Therefore, the alarm B will not be powered on and will not sound, indicating that the electrostatic shielding effect of the inkjet printer 7 is good (the static voltage signal conducted to the copper plate through the shell is relatively small and will not affect the operation of the inkjet printer). When the humidity inside test chamber 1 is within the set range and the static pressure value is set, and the electrostatic shielding effect of the inkjet printer 7's casing is poor, the static voltage signal detected by the copper plate M is relatively large. The field-effect transistor Q2 is no longer in a zero-bias state, and the resistance between its drain and source is large. The voltage drop between the field-effect transistor Q2 and the adjustable resistor RP2 is large. Thus, the 12V power supply, through the voltage drop between the field-effect transistor Q2 and the adjustable resistor RP2, enters the base of transistor Q3, which is higher than 0.7V. Transistor Q3 conducts, and its emitter outputs a high level that enters the base of transistor Q4 (due to the filtering effect of capacitor C1). Transistor Q4 conducts, and its collector outputs a low level that enters the negative power input terminal of alarm B. Alarm B will be powered on and sound an alarm, indicating that the electrostatic shielding effect of the inkjet printer 7's casing is poor (in reality, the static voltage signal conducted through the casing to the copper plate is relatively large, which will affect the operation of the inkjet printer). Turning off the main power switch and opening the cover to remove the inkjet printer completes the entire testing process.

[0021] Figures 1-2 As shown above, this invention can conveniently detect the static electricity absorption (i.e., static electricity shielding) of the inkjet printer casing under different air humidity environments and different static electricity intensities by using an electrostatic generator, humidity monitoring circuit, and humidity simulation mechanism. During the detection, when the static electricity shielding effect of the casing is lower than the threshold, the electrostatic tolerance monitoring circuit can promptly alert the measurement personnel, preventing excessive static electricity from damaging the inkjet printer. This provides strong technical support for manufacturers to ensure product quality and for end users to use inkjet printers normally.

[0022] The foregoing description illustrates the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention.

[0023] Furthermore, it should be understood that although this specification describes the embodiments, the embodiments do not necessarily contain only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for detecting the electrostatic resistance of an inkjet printer application, comprising a test box, an electrostatic generator, a humidity sensor, characterized in that, The humidity monitoring circuit, the static electricity tolerance monitoring circuit, the temperature monitoring circuit and the humidity simulation mechanism are arranged in the component box.

2. The device for detecting the anti-static property applied to an inkjet printer according to claim 1, wherein The lower end of the humidity sensor is fixedly connected with the signal input end of the humidity monitoring circuit, the power output end of the humidity monitoring circuit is electrically connected with the power input end of the electromagnetic valve, and the power output end of the temperature monitoring circuit is electrically connected with the power input end of the electric heating plate.

3. The device for detecting the anti-static property applied to an inkjet printer according to claim 1, wherein The electromagnetic valve is a normally open valve core electromagnetic valve.

4. The device for detecting the anti-static property applied to an inkjet printer according to claim 1, wherein The humidity monitoring circuit comprises an adjustable resistor, a resistor and a triode which are electrically connected.

5. The device for detecting the anti-static property applied to an inkjet printer according to claim 1, wherein The static electricity tolerance monitoring circuit comprises a metal sheet, a triode, a capacitor, an alarm and a field effect tube which are electrically connected and are matched with a vacuum chuck.

6. The device for detecting the anti-static property applied to an inkjet printer according to claim 1, wherein The temperature monitoring circuit is a relay, and the positive power input end of the relay is connected with one end of the temperature switch.

7. The device for detecting the anti-static property applied to an inkjet printer according to claim 1, wherein The upper end of the heating tank is provided with a gas release valve. The upper end of the humidity sensor is fixedly connected with the signal input end of the humidity monitoring circuit, the power output end of the humidity monitoring circuit is electrically connected with the power input end of the electromagnetic valve, and the power output end of the temperature monitoring circuit is electrically connected with the power input end of the electric heating plate. The electromagnetic valve is a normally open valve core electromagnetic valve. The humidity monitoring circuit comprises an adjustable resistor, a resistor and a triode which are electrically connected. The static electricity tolerance monitoring circuit comprises a metal sheet, a triode, a capacitor, an alarm and a field effect tube which are electrically connected and are matched with a vacuum chuck. The temperature monitoring circuit is a relay, and the positive power input end of the relay is connected with one end of the temperature switch. The upper end of the heating tank is provided with a gas release valve.

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