Control system of charging roller

Abstract

The utility model relates to a control system of a charging roller, comprising a driving mechanism used for driving the charging roller to rotate; the main control unit is electrically connected with the driving mechanism and used for controlling the driving mechanism to act according to the printing command; the power supply output end of the power supply module is electrically connected with the charging roller; the control system of the charging roller is characterized in that the output end of the main control unit is electrically connected with the power input end of the power module, the control system of the charging roller further comprises a feedback module electrically connected with the power module and the main control unit, and the feedback module is used for converting current signals output by the power module into voltage signals. The voltage signal is output to the main control unit; and the main control unit is configured to obtain a contact result of the charging roller and the power supply module according to the voltage signal output by the feedback module. According to the control system, the problem of poor printing portrait caused by poor contact between the conducting strip of the charging roller and the power module can be avoided, and the image quality stability is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of laser printing, in particular to a control system of a charging roller. Background Art

[0002] The toner cartridge is the core imaging component in a laser printer. The toner cartridge in a laser printer mainly includes a toner bin, a photosensitive drum, a charging roller, a magnetic roller, a scraper and a number of rotating gears. However, the toner cartridges in the prior art all use a conductive part (which can be a conductive sheet or a conductive bracket) to cooperate with the charging roller to achieve electrical connection between the charging roller and an external power source.

[0003] In order to improve the contact stability between the conductive part and the charging roller, improve the intermittent power supply caused by poor contact between the conductive part and the charging roller, prevent intermittent contact problems, and effectively improve the stability of image quality. For example, the Chinese utility model patent with patent number ZL202221394173.2 (authorization announcement number CN217655420U) discloses a conductive structure of a charging roller, an imaging device, and a printer; and the Chinese utility model patent with patent number ZL202221251592.0 (authorization announcement number CN217386139U) discloses a conductive structure of a toner cartridge and a toner cartridge.

[0004] Although the above two patents can improve the contact stability between the conductive part and the charging roller by improving the structure of the conductive part, in the prior art, the laser printer assumes that the toner cartridge is in a normal state as long as it identifies the toner cartridge during the self-test process, and usually does not detect the contact state between the conductive part and the external power supply. If the contact between the conductive part and the external power supply is poor, the photosensitive drum of the toner cartridge will be abnormally charged when the printer is working, which will cause abnormal images printed by the printer.

[0005] Therefore, it is necessary to further improve the prior art. Utility Model Content

[0006] The technical problem to be solved by the utility model is to provide a control system for a charging roller which can detect the contact state between a conductive member and an external power source, thereby effectively avoiding abnormal printing of images.

[0007] The technical solution adopted by the utility model to solve the above technical problems is: a control system for a charging roller, comprising:

[0008] A driving mechanism, connected to the charging roller driving device, for driving the charging roller to rotate;

[0009] A main control unit is electrically connected to the driving mechanism and is used to control the driving mechanism to perform actions according to a printing command;

[0010] A power module, whose power output terminal is electrically connected to the charging roller;

[0011] It is characterized in that: the output end of the main control unit is electrically connected to the power input end of the power module, and the control system of the charging roller also includes a feedback module electrically connected to the power module and the main control unit respectively, and the feedback module is used to convert the current signal output by the power module into a voltage signal, and then output the voltage signal to the main control unit; the main control unit is configured to obtain the contact result between the charging roller and the power module according to the voltage signal output by the feedback module.

[0012] In order to improve the accuracy of the contact result between the charging roller and the power module, the feedback module is electrically connected to the main control unit through a sampling module, and the sampling module is used to sample the voltage signal output by the feedback module and transmit the sampling result to the main control unit.

[0013] The first method for processing the sampling result of the sampling module is that the main control unit is configured to compare the sampling result of the sampling module with a preset voltage, and obtain the contact result of the charging roller and the power module according to the comparison result, and the contact result is good contact or bad contact. In this method, the main control unit performs comparative analysis to obtain the contact result of the charging roller and the power module.

[0014] The second method for processing the sampling result of the sampling module is: a comparator is further provided between the sampling module and the main control unit, the first input end of the comparator is connected to the output end of the sampling module, the second input end of the comparator is connected to an external power supply for inputting a preset voltage, and the output end of the comparator is connected to the main control unit. This method is to perform automatic calculations through the comparator without the need for analysis and processing by the main control unit. The main control unit can directly judge based on the output result of the comparator output end, and thus obtain the contact result between the charging roller and the power module.

[0015] To avoid printer errors, the driving mechanism is a motor, and the main control unit outputs a control signal to the power module after the motor drives the charging roller to rotate stably, so that the power module outputs a corresponding voltage to the charging roller according to the control signal.

[0016] Preferably, the control signal is a PWM signal.

[0017] There can be many kinds of circuits for the above-mentioned feedback module. Preferably, the feedback module includes a voltage divider circuit, which is composed of at least two voltage divider resistors connected in series. The connecting line between any two voltage divider resistors corresponds to the output end of the voltage divider circuit, and the output end of the voltage divider circuit is the output end of the above-mentioned feedback module.

[0018] Preferably, the sampling module is an ADC sampling port of a main control unit.

[0019] Compared with the prior art, the advantages of the utility model are: on the one hand, the control system converts the current signal output by the power module of the feedback module into a voltage signal, and then outputs the voltage signal to the main control unit, that is, the main control unit can obtain the contact result between the charging roller and the power module according to the voltage signal output by the feedback module; on the other hand, the output end of the main control unit is electrically connected to the power input end of the power module, so that the power module is controlled by the control of the main control unit. Therefore, the control system can avoid the problem of poor printing image caused by poor contact between the conductive sheet of the charging roller and the power module, and effectively improve the stability of image quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a principle block diagram of the charging roller control system in the first embodiment of the utility model;

[0021] Figure 2 This is a circuit diagram of the charging roller control system in the first embodiment of the utility model. DETAILED DESCRIPTION

[0022] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0023] Embodiment 1:

[0024] like Figure 1 As shown, the control system of the charging roller in this embodiment includes a driving mechanism 1 , a main control unit 3 , a power module 4 and a feedback module 5 .

[0025] The driving mechanism 1 is connected to the charging roller 2 for driving the charging roller 2 to rotate. In this embodiment, the driving mechanism 1 is a motor. The rotation method of the charging roller 2 is a prior art and will not be described in detail here. The main control unit 3 is electrically connected to the driving mechanism 1 for controlling the driving mechanism 1 to act according to the printing command. After the motor drives the charging roller 2 to rotate stably, the main control unit 3 outputs a control signal (the control signal in this embodiment is a PWM signal) to the power module 4, so that the power module 4 outputs a corresponding voltage to the charging roller 2 according to the control signal. In this embodiment, the main control unit 3 adopts the SOC system (System on Chip, generally referred to as a system-level chip), the power input end of the power module 4 is electrically connected to the output end of the main control unit 3, and the power output end of the power module 4 is electrically connected to the charging roller 2. Figure 2 As shown, the power module 4 in this embodiment includes a 24V external power supply and a transformer T1 electrically connected to the external power supply; Figure 2 In the circuit, it is used to pass the resistor and capacitor circuit (such as Figure 2 The capacitor C3 and the resistor R4 connected in parallel in the middle phase are equivalent to simulate the relationship between the charging roller 2 and the photosensitive drum inside the toner drum of the printer, and Figure 2 The power module 4 is controlled by the conductive sheet 7 to supply power to the charging roller 2 .

[0026] The feedback module 5 is electrically connected to the power module 4 and the main control unit 3 respectively. The feedback module 5 is used to convert the current signal output by the power module 4 into a voltage signal, and then output the voltage signal to the main control unit 3; the main control unit 3 is configured to obtain the contact result between the charging roller 2 and the power module 4 according to the voltage signal output by the feedback module 5. Figure 1 As shown, the feedback module 5 is electrically connected to the main control unit 3 through the sampling module 6, and the sampling module 6 is used to sample the voltage signal output by the feedback module 5 and transmit the sampling result to the main control unit 3. In this embodiment, the sampling module 6 is an ADC sampling port of the main control unit 3.

[0027] In this embodiment, the main control unit 3 is configured to compare the sampling result of the sampling module 6 with the preset voltage, and obtain the contact result between the charging roller 2 and the power module 4 according to the comparison result, and the contact result is good contact or bad contact.

[0028] The feedback module 5 includes a voltage divider circuit 51, which is formed by at least two voltage divider resistors connected in series. The connection line between any two voltage divider resistors corresponds to the output end of the voltage divider circuit 51, and the output end of the voltage divider circuit 51 is the output end of the feedback module 5. Figure 2 As shown, the voltage divider circuit 51 is composed of a second voltage divider resistor R2 and a third voltage divider resistor R3 , and the connection line between the second voltage divider resistor R2 and the third voltage divider resistor R3 is the output end of the voltage divider circuit 51 .

[0029] The working process in this embodiment is as follows: when the printer executes a print instruction, there are two stages: pre-printing and printing. In the pre-printing stage, the printer calibrates the voltage output by the power module, and the voltage control of the charging roller is performed in this stage; the main control unit outputs a PWM control signal to the motor after receiving the print command, and then outputs a PWM control signal to the power module after the motor rotates stably. The power module outputs voltage to the charging roller, and at the same time outputs the current of the power module to the feedback module. The feedback module converts the current signal into a voltage signal and outputs it to the main control unit. The main control unit calibrates the output voltage of the power module according to the voltage value fed back by the feedback module.

[0030] The contact detection between the conductive sheet of the charging roller and the power supply module is actually judged by comparing the voltage signal output by the feedback module with the set reference threshold value to determine whether the contact is good; the photosensitive drum is equivalent to a capacitive impedance in the circuit of the power supply module. When the contact is poor, the circuit impedance of the power supply module is infinite, the current of the power supply module is small, and the voltage value output by the feedback module is small; when the contact is good, the circuit impedance of the power supply module meets the design requirements, the current value of the power supply module is normal, and the voltage value output by the feedback module is normal.

[0031] After the print command is issued, the printer runs normally to the pre-printing stage. To eliminate the accidental risk of the voltage value output by the feedback module, the voltage signal output by the feedback module is periodically sampled by the sampling module N times through ADC. After removing the maximum and minimum values, the average value x of the data group is obtained as the output voltage of the feedback module this time; then the average value x of the output voltage sampling data group of the feedback module is compared with the reference threshold A (a suitable reference threshold value A is set through testing big data), and the contact on-off situation between the charging roller and the power supply module is judged according to the comparison result:

[0032] When x > A, it is determined that the contact state between the charging roller and the power supply module is good, and the print command can be continued to be executed;

[0033] When x < A, it is determined that the contact state between the charging roller and the power supply module is poor, the printer interrupts the printing operation, and after reinstalling the toner cartridge, it re-enters the pre-printing state for detection;

[0034] The reason for choosing to start sampling the voltage signal output by the feedback module after the second time (this time is 400ms): originally, it was preset to start sampling the voltage signal output by the feedback module after the first time (this time is 160ms). During the full-scenario test, the voltage signal output by the feedback module showed a slow power-on phenomenon in the low-temperature environment, resulting in the final conversion result of the sampling signal being X < A, determining poor contact, and the printer reporting an error; but the printing task was completed normally, causing a poor user experience. Detecting after delaying the second time can ensure that the voltage signal output by the feedback module is in a stable state in all environments, and the detection result is more accurate and reliable.

[0035] Embodiment 2:

[0036] Different from Embodiment 1, a comparator (not shown in the figure) is further provided between the sampling module 6 and the main control unit 3. The first input end of the comparator is connected to the output end of the sampling module 6, the second input end of the comparator is connected to an external power supply for inputting a preset voltage, and the output end of the comparator is connected to the main control unit 3.

[0037] The above-mentioned comparator is used to compare the sampling result of the sampling module 6 with the preset voltage (that is, the above-mentioned reference threshold A). The comparator can directly obtain the comparison result, that is: the main control unit 3 can directly obtain the contact result between the charging roller and the power module according to the output result of the comparator, thereby improving the processing speed of the main control unit 3.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A control system for a charging roller, comprising: A driving mechanism (1) is connected to the charging roller (2) and is used to drive the charging roller (2) to rotate; A main control unit (3) is electrically connected to the driving mechanism (1) and is used to control the driving mechanism (1) to perform actions according to a printing command; A power module (4), whose power output end is electrically connected to the charging roller (2); The invention is characterized in that: the output end of the main control unit (3) is electrically connected to the power input end of the power module (4); the control system of the charging roller also includes a feedback module (5) electrically connected to the power module (4) and the main control unit (3), respectively; the feedback module (5) is used to convert the current signal output by the power module (4) into a voltage signal, and then output the voltage signal to the main control unit (3); the main control unit (3) is configured to obtain the contact result between the charging roller (2) and the power module (4) according to the voltage signal output by the feedback module (5).

2. The control system of the charging roller according to claim 1, characterized in that: The feedback module (5) is electrically connected to the main control unit (3) via a sampling module (6); the sampling module (6) is used to sample the voltage signal output by the feedback module (5) and transmit the sampling result to the main control unit (3).

3. The control system of the charging roller according to claim 2, characterized in that: The main control unit (3) is configured to compare the sampling result of the sampling module (6) with a preset voltage, and obtain a contact result between the charging roller (2) and the power module (4) based on the comparison result, wherein the contact result is good contact or poor contact.

4. The control system of the charging roller according to claim 2, characterized in that: A comparator is also provided between the sampling module (6) and the main control unit (3); a first input end of the comparator is connected to an output end of the sampling module (6); a second input end of the comparator is connected to an external power supply for inputting a preset voltage; and an output end of the comparator is connected to the main control unit (3).

5. The control system of the charging roller according to claim 1, characterized in that: The driving mechanism (1) is a motor, and the main control unit (3) outputs a control signal to the power module (4) after the motor drives the charging roller (2) to rotate stably, so that the power module (4) outputs a corresponding voltage to the charging roller (2) according to the control signal.

6. The control system of the charging roller according to claim 5, characterized in that: The control signal is a PWM signal.

7. The control system of the charging roller according to any one of claims 1 to 5, characterized in that: The feedback module (5) comprises a voltage divider circuit (51), wherein the voltage divider circuit (51) is formed by at least two voltage divider resistors connected in series, and a connecting line between any two voltage divider resistors corresponds to an output end of the voltage divider circuit (51), and the output end of the voltage divider circuit (51) is the output end of the feedback module (5).

8. The control system of the charging roller according to any one of claims 2 to 4, characterized in that: The sampling module (6) is an ADC sampling port of the main control unit (3).

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