US-12617201-B2 - Image forming apparatus, image forming method, and computer-readable medium

US12617201B2US 12617201 B2US12617201 B2US 12617201B2US-12617201-B2

Abstract

An image forming apparatus includes a control unit. In a case where a total amount of liquid discharged from all of at least one liquid discharge head connected to one or more channel pipelines communicating with a tank until a predetermined first time period elapses from a first time is a first discharge amount and a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until the first time period elapses from a second time later than the first time by the first time period is a second discharge amount, the control unit is configured to adjust the discharge amount from a time later than the second time by the first time period, based on a value obtained by subtracting the second discharge amount from the first discharge amount.

Inventors

Kohta AKIYAMA

Assignees

Kohta AKIYAMA

Dates

Publication Date: 20260505
Application Date: 20240509
Priority Date: 20230516

Claims (9)

1 . An image forming apparatus comprising: a tank configured to hold liquid; one or more channel pipelines communicating with the tank; at least one liquid discharge head connected to the one or more channel pipelines and configured to discharge the liquid held in the tank; a detection unit configured to detect a discharge amount of liquid discharged per predetermined time period from the at least one liquid discharge head; and a control unit configured to adjust the discharge amount, wherein in a case where a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until a predetermined first time period elapses from a first time is a first discharge amount and a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until the first time period elapses from a second time later than the first time by the first time period is a second discharge amount, the control unit is configured to adjust the discharge amount from a time later than the second time by the first time period, based on a value obtained by subtracting the second discharge amount from the first discharge amount.
2 . The image forming apparatus according to claim 1 , wherein the control unit is configured to calculate a total amount of liquid discharged from the liquid discharge head until the first time period elapses from the first time or second time, by counting numbers of liquid droplets discharged from the at least one liquid discharge head for respective sizes of the liquid droplets and totaling the numbers of liquid droplets counted, based on image data output to the liquid discharge head.
3 . The image forming apparatus according to claim 1 , wherein the control unit is configured to adjust the discharge amount by changing an amount of liquid discharged to a printed medium per unit area.
4 . The image forming apparatus according to claim 1 , wherein the control unit is configured to adjust the discharge amount only in a case where the value obtained by subtracting the second discharge amount from the first discharge amount exceeds a predetermined value.
5 . The image forming apparatus according to claim 4 , wherein the control unit is configured to perform adjustment of the discharge amount over a predetermined second time period, and in a case where a value obtained by subtracting the second discharge amount from the first discharge amount exceeds the predetermined value again while the control unit is performing the adjustment of the discharge amount, perform new adjustment of the discharge amount redundantly with respect to the adjustment of the discharge amount being performed.
6 . The image forming apparatus according to claim 1 , wherein the control unit is configured to determine a method of adjusting the discharge amount for each liquid to be discharged.
7 . The image forming apparatus according to claim 1 , wherein the control unit is configured to change a method of adjusting the discharge amount according to a temperature of the liquid in the one or more channel pipelines.
8 . An image forming method executed by an image forming apparatus having a tank configured to hold liquid, one or more channel pipelines communicating with the tank, and at least one liquid discharge head connected to the one or more channel pipelines and configured to discharge the liquid held in the tank, the image forming method comprising: detecting a discharge amount of liquid discharged per predetermined time period from the at least one liquid discharge head; adjusting the discharge amount; and in a case where a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until a predetermined first time period elapses from a first time is a first discharge amount and a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until the first time period elapses from a second time later than the first time by the first time period is a second discharge amount, adjusting the discharge amount from a time later than the second time by the first time period, based on a value obtained by subtracting the second discharge amount from the first discharge amount.
9 . A non-transitory computer-readable medium including programmed instructions that cause a computer configured to control an image forming apparatus including a tank configured to hold liquid, one or more channel pipelines communicating with the tank, and at least one liquid discharge head connected to the one or more channel pipelines and configured to discharge the liquid held in the tank, to function as: a detection unit configured to detect a discharge amount of liquid discharged per predetermined time period from the at least one liquid discharge head; and a control unit configured to adjust the discharge amount, wherein in a case where a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until a predetermined first time period elapses from a first time is a first discharge amount and a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until the first time period elapses from a second time later than the first time by the first time period is a second discharge amount, the control unit is configured to adjust the discharge amount from a time later than the second time by the first time period, based on a value obtained by subtracting the second discharge amount from the first discharge amount.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2023-081132, filed on May 16, 2023. The contents of which are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, an image forming method, and a computer-readable medium. 2. Description of the Related Art Increase in the flow rate of liquid, such as ink, flowing through an ink feeding channel to a liquid discharge head used in an image forming apparatus for high speed printing leads to increase in pressure fluctuation that occurs in the ink feeding channel and to a problem of causing density variation in a discharge image and reducing the image quality until pressure oscillation caused by the pressure fluctuation is damped. Techniques have been developed to address this problem, the techniques being for reducing the pressure fluctuation by making the ink feeding channel thicker, making the ink feeding channel shorter, or providing, near the liquid discharge head, a damper to alleviate the pressure fluctuation. In a control method disclosed in Japanese Patent No. 3772805, for the purpose of correcting a change in liquid volume that occurs upon high-frequency driving, the amount of liquid droplets discharged is actually measured for each head at the time of high-frequency driving, a frequency characteristic ink amount ID is set for each head, and correction is performed. However, making the ink feeding channel thicker according to the above mentioned technique increases the size of the image forming apparatus. Furthermore, making the ink feeding channel shorter or providing the damper near the liquid discharge head obstructs placement of the liquid discharge head and the above mentioned technique thus fails to be adapted to increases in fluctuation of the flow rate due to the recent improvement in the printing speed and may still have image degradation. The technique described in Japanese Patent No. 3772805 fails to stop the density variation in an image due to the pressure fluctuation before the pressure oscillation caused in the ink feeding channel is damped. Specifically, the technique described in Japanese Patent No. 3772805 enables correction of a density change due to the frequency characteristic of the head, the density change being caused while driving is performed at each frequency when the drive frequency of a particular discharge is changed, but it is still difficult, with the technique described in Japanese Patent No. 3772805, to reduce the density variation in a printed image caused by damped oscillation of pressure generated in the ink feeding channel. The present invention has been made in view of the above, and an object thereof is to provide an image forming apparatus, an image forming method, and a program that enable, for image forming apparatuses with improved printing speed, prevention of increase in sizes of their bodies and reduction of density variation in images due to pressure fluctuation that occurs in their ink feeding channels. SUMMARY OF THE INVENTION According to an aspect of the present invention, an image forming apparatus includes a tank, one or more channel pipelines, at least one liquid discharge head, a detection unit, and a control unit. The tank is configured to hold liquid. The one or more channel pipelines communicate with the tank. The at least one liquid discharge head is connected to the one or more channel pipelines and configured to discharge the liquid held in the tank. The detection unit is configured to detect a discharge amount of liquid discharged per predetermined time period from the at least one liquid discharge head. The control unit is configured to adjust the discharge amount. In a case where a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until a predetermined first time period elapses from a first time is a first discharge amount and a total amount of liquid discharged from all of the at least one liquid discharge head connected to the one or more channel pipelines until the first time period elapses from a second time later than the first time by the first time period is a second discharge amount, the control unit is configured to adjust the discharge amount from a time later than the second time by the first time period, based on a value obtained by subtracting the second discharge amount from the first discharge amount. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating an example of a cross section of a liquid discharge head forming a recording head of an image forming apparatus according to a first embodiment, the cross section being along a longitudinal direction of a liquid chamber of the liquid discharge head; FIG. 2 is a diagram illustrating an example of a cross section of the liquid discharge