Method of detecting and adjusting temperature of inkjet printer head and image forming apparatus

Abstract

The present application relates to a method for detecting and adjusting the temperature of a printhead of an inkjet printer and an image forming device, the method comprising: before the inkjet printer starts printing, calculating the temperature of the ink ejection port T at the start of printing for each printing area according to the data information of the image to be printed; when T is lower than Tem1, first performing a heating operation on the ink ejection port before printing the area; when T is higher than Tem2, first performing a cooling operation on the ink ejection port before printing the area; the cooling operation is to pause printing, or a heat dissipation member is provided on the ink cartridge or a carrier for carrying the ink cartridge, and the heat dissipation member can be in contact with at least part of the printhead; after the inkjet printer starts printing, continuously measuring the temperature of the periphery of the ink ejection port by a temperature detection module, and controlling the temperature of the ink ejection port of the inkjet printer to always be within the range of Tem1-Tem2. The method can stabilize the temperature of a specific area in the image forming area, so as to ensure that a uniform image is obtained.

Description

Technical Field

[0001] This invention relates to the field of printer technology, and more particularly to a method for detecting and adjusting the printhead temperature of an inkjet printer and an image forming apparatus. Background Technology

[0002] In inkjet printing technology, ink needs to be heated before it can be effectively output and achieve good printing results. Current technology involves heating the ink directly in the printhead after it enters the printhead, causing the ink temperature to rise instantly and generate bubbles, thus enabling the output of ink droplets for printing.

[0003] However, excessively high printhead temperatures can damage the printhead. Therefore, a high-temperature threshold is typically set during printing. When the printhead temperature reaches this threshold, heating is stopped, and printing ceases to allow the printhead to cool down. Once the printhead temperature has dropped to the set temperature, the heating device is then activated to reheat the printhead, and printing resumes. However, if the printer's initial temperature is below the set temperature, even if the heater in the ink cartridge is running, it may not be able to fully achieve its discharge characteristics, resulting in an uneven image.

[0004] To address the aforementioned technical problems, Chinese invention patent ZL200910004843.8 (authorization announcement number CN101491967B) discloses a liquid ejection device and method. The liquid ejection device includes: a head that ejects liquid by a drive signal; a drive signal generation unit that generates the drive signal; a sensor for detecting the temperature of the head; a generation unit sensor for detecting the temperature of the drive signal generation unit; and a control unit. Based on the detection results of the sensor and the generation unit sensor, the control unit waits for the drive signal to eject liquid from the head. The control unit determines a first standby time (the waiting period) based on the sensor's detection results and a second standby time based on the generation unit sensor's detection results. Liquid is ejected from the head by the drive signal after the longer of the first and second standby times. While this liquid ejection device can suppress the rise in head temperature, its temperature control method is relatively complex. Therefore, further improvements to the existing technology are needed. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a method for detecting and adjusting the printhead temperature of an inkjet printer that ensures uniform image acquisition and has a simple control method, in contrast to the above-mentioned prior art.

[0006] The second technical problem to be solved by the present invention is to provide an image forming apparatus that applies the above-described method for detecting and adjusting the printhead temperature of an inkjet printer.

[0007] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a method for detecting and adjusting the temperature of an inkjet printer printhead, wherein the inkjet printer has an ink cartridge connected to the printhead, and the printhead has multiple ink nozzles, characterized in that: the minimum threshold of the ink nozzle temperature is set to Tem1, and the maximum threshold is set to Tem2.

[0008] Before the inkjet printer starts printing, the inkjet nozzle temperature T at the start of printing in each printing area is calculated based on the data information of the image to be printed.

[0009] When T is lower than Tem1, the inkjet nozzle is heated first before printing in this area;

[0010] When T is higher than Tem2, the inkjet nozzle is cooled first before printing in this area;

[0011] The cooling operation is to pause printing, or the cooling operation is to provide a heat dissipation component on the ink cartridge or the carrier for holding the ink cartridge, the heat dissipation component being able to contact at least part of the printhead;

[0012] After the inkjet printer starts printing, the temperature detection module continuously measures the temperature around the inkjet nozzle and controls the temperature of the inkjet printer nozzle to always be within the range of Tem1 to Tem2.

[0013] Preferably, the printhead is preheated before printing with the inkjet printer. When the temperature detection module detects that the temperature of the outer periphery of the inkjet nozzle reaches Tem3, Tem3-Tem1=△T, where △T is a preset difference, the inkjet printer starts printing.

[0014] Preferably, in the first method, the specific process of performing the heating operation is as follows:

[0015] The ink cartridge has a substrate, on which there are energy conversion elements and a heating device. The energy conversion elements and the heating device are activated to perform a heating operation.

[0016] The preferred second method involves the following specific process for performing the heating operation:

[0017] The inkjet nozzle is preheated using a pre-pulse method.

[0018] Preferably, the heat sink is a plurality of heat sinks, each heat sink being disposed between two adjacent nozzles.

[0019] To achieve temperature detection, the temperature detection module includes multiple thermistors arranged circumferentially along each inkjet nozzle, and all thermistors are connected in series.

[0020] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: an image forming apparatus, characterized in that: it applies the method described above for detecting and adjusting the temperature of an inkjet printer printhead.

[0021] Compared with the prior art, the advantages of this invention are as follows: Before the inkjet printer starts printing, the inkjet nozzle temperature T at the start of printing in each printing area is calculated based on the data information of the image to be printed. When T is lower than Tem1, the inkjet nozzle is first heated before printing in that area; when T is higher than Tem2, the inkjet nozzle is first cooled before printing in that area. Thus, after the inkjet printer starts printing, the temperature detection module continuously measures the temperature around the inkjet nozzle and controls the temperature of the inkjet printer nozzle to always be within the range of Tem1 to Tem2, improving the temperature stability during printing and preventing excessively high or low temperatures from affecting the printing effect. Therefore, it can stabilize the temperature of specific areas in the image formation area to ensure a uniform image. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an inkjet printer printhead in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the temperature detection of the nozzle in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the area division of the nozzle in an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the installation of the heat sink in an embodiment of the present invention. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0027] Inkjet printers have ink cartridges connected to the printhead, which has multiple ink nozzles.

[0028] In this embodiment, the method for detecting and adjusting the printhead temperature of an inkjet printer involves dividing the image information to be printed into several regions according to the main scanning direction and the sub-scanning direction (i.e., the horizontal and vertical printing directions) before the inkjet printer prints. Since the image information to be printed in each region is different, the number of inkjet dots in each region is also different. Therefore, the temperature T of the printhead when it starts printing in each region is calculated by obtaining the dot distribution information of each color in each color block from the image information.

[0029] The minimum threshold for ink cartridge printhead temperature is set to Tem1, and the maximum threshold is set to Tem2. In this implementation, Tem1 = 40℃ and Tem2 = 80℃ (the threshold temperatures are obtained from actual experimental data). When the printhead temperature is lower than Tem1 or higher than Tem2, the printed image quality will decrease. Therefore, before printing, temperature control planning can be carried out in advance based on the calculated temperature T at the start of printing in each area (it can be planned in advance to perform a heating operation before normal printing in a certain area, or to perform a cooling operation before normal printing in a certain area). This ensures that the printhead temperature is within the threshold range throughout the printing process, and the temperature of the inkjet nozzle is uniformly distributed throughout the printing process through advance temperature control planning. After the inkjet printer starts printing, the temperature detection module continuously measures the temperature around the inkjet nozzle and controls the temperature around the inkjet printer printhead to always be within the preset threshold range.

[0030] The temperature detection module in this embodiment includes multiple thermistors arranged circumferentially along each inkjet nozzle, and all thermistors are connected in series.

[0031] Specifically, the process of controlling the temperature around the printhead of the inkjet printer to always be within the preset threshold range is as follows: when the temperature detected by the temperature detection module is lower than the minimum value of the preset threshold range (i.e., Tem1), a heating operation is performed; when the temperature detected by the temperature detection module is higher than the maximum value of the preset threshold range (i.e., Tem2), a cooling operation is performed.

[0032] In this embodiment, the specific process of performing the heating operation is as follows: the ink cartridge has a substrate, and the substrate has an energy conversion element and a heating device. Then, the energy conversion element and the heating device are activated to perform the heating operation.

[0033] In this embodiment, the specific process of performing the cooling operation is as follows: a heat dissipation component is provided on the ink cartridge or the carrier used to support the ink cartridge, and the heat dissipation component can contact at least part of the printhead. For example... Figure 4 As shown, the heat sink in this embodiment consists of multiple heat sinks, each positioned between two adjacent printheads. The heat sinks provide excellent cooling, especially at high temperatures, shortening the temperature drop time or allowing cooling to be achieved by pausing printing.

[0034] Before printing, the printhead is preheated. When the temperature detection module detects that the temperature around the inkjet nozzle reaches Tem3, Tem3 - Tem1 = ΔT, where ΔT is a preset difference. The inkjet printer then begins printing. Since there is a delay between receiving the print command and the printhead starting to print, to ensure the printhead temperature reaches Tem1 = 40℃ at the start of printing, in this embodiment, ΔT = 5℃ and Tem3 = 35℃. That is, printing can begin when the temperature detection module detects that the temperature around the inkjet nozzle reaches 35℃. When the image is formed, the printhead temperature reaches Tem1. The aforementioned ΔT can be confirmed through experience or experimentation. During printing, the printhead moves relative to the printing medium along the main scanning direction, while the printing medium also moves relative to the printer, causing the printhead to move relative to the printing medium along the secondary scanning direction, thus forming a printed image on the printing medium. The printing medium is typically paper, cloth, etc. Depending on the printer, the specific directions of the main scanning direction and the secondary scanning direction are determined. In this embodiment, the main scanning direction is the left-right direction, and the secondary scanning direction is the front-back direction.

[0035] like Figure 1 As shown, in this embodiment, there are four sets of printheads, each set of printheads being connected to ink cartridges containing black, cyan, magenta, and yellow inks, respectively. Figure 1 In this context, the abbreviation BK stands for black, corresponding to the color black. Figure 1 The abbreviation CL in the printer stands for color, corresponding to cyan, magenta, and yellow. It can also connect ink cartridges containing the four colors (black, cyan, magenta, and yellow) in a set of printheads. The ink cartridges are mounted on a carrier and move along the main scanning direction on the printer body to dispense ink.

[0036] like Figure 2 As shown, multiple thermistors are connected in series around the printhead, which is connected to the ink cartridges containing black, cyan, magenta, and yellow inks. These thermistors are R1, R2, R3, R4, R5, and R6. Figure 3 As shown, the outer periphery of a certain printhead is divided into 6 regions, namely region 1, region 2, region 3, region 4, region 5 and region 6. By detecting and adjusting the temperature of all regions, uniform printing can be ensured.

[0037] This embodiment also relates to an image forming apparatus that applies the method described above for detecting and adjusting the printhead temperature of an inkjet printer.

[0038] Example 2:

[0039] Unlike Embodiment 1, the specific process of performing the heating operation in this embodiment is as follows: the inkjet nozzle is preheated by a pre-pulse.

[0040] This allows pre-pulses to be applied to areas requiring increased temperature, resulting in a more uniform temperature distribution across the entire printhead. This enables the ink cartridge to be set to the appropriate dispensing state for a consistent image. Additionally, it creates a temperature difference between the printhead and other cool air before ink begins to exit, thus achieving more efficient printing.

[0041] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for detecting and adjusting the temperature of an inkjet printer printhead, the inkjet printer having an ink cartridge connected to the printhead, the printhead having multiple ink nozzles, characterized in that: The minimum threshold for inkjet nozzle temperature is set to Tem1, and the maximum threshold is set to Tem2. Before the inkjet printer starts printing, the inkjet nozzle temperature T at the start of printing in each printing area is calculated based on the data information of the image to be printed. When T is lower than Tem1, the inkjet nozzle is heated first before printing in this area; When T is higher than Tem2, the inkjet nozzle is cooled first before printing in this area; The cooling operation is to pause printing, or the cooling operation is to provide a heat dissipation component on the ink cartridge or the carrier for holding the ink cartridge, the heat dissipation component being able to contact at least part of the printhead; Before printing, the printhead is preheated. When the temperature detection module detects that the temperature of the outer periphery of the inkjet nozzle reaches Tem3, Tem3-Tem1=△T, where △T is a preset difference, the inkjet printer starts printing. After the inkjet printer starts printing, the temperature detection module continuously measures the temperature around the inkjet nozzle and controls the temperature of the inkjet printer nozzle to always be within the range of Tem1 to Tem2.

2. The method according to claim 1, characterized in that: The specific process for performing the heating operation is as follows: The ink cartridge has a substrate, on which there are energy conversion elements and a heating device. The energy conversion elements and the heating device are activated to perform a heating operation.

3. The method according to claim 2, characterized in that: The specific process for performing the heating operation is as follows: The inkjet nozzle is preheated using a pre-pulse method.

4. The method according to claim 1, characterized in that: The heat dissipation component consists of multiple heat sinks, with each heat sink positioned between two adjacent nozzles.

5. The method according to any one of claims 1 to 4, characterized in that: The temperature detection module includes multiple thermistors arranged circumferentially along each inkjet nozzle, and all thermistors are connected in series.

6. An image forming apparatus, characterized in that: The application has the method for detecting and adjusting the printhead temperature of an inkjet printer as described in any one of claims 1 to 5.

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