JP2016161633A - Manufacturing device of operation panel, operation panel, display device, manufacturing method of operation panel, and display method of display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing device of an operation panel capable of preventing flicker on a screen even if an individual difference exists in structure components of the operation panel, a display device, a manufacturing method of the operation panel, and a display method of the display device.SOLUTION: A plant side screen rewriting part 203 periodically rewrites a screen display part 201 of an operation panel by a preset refresh rate. A plant side lighting control part 204 makes a back light part 202 of the operation panel to be lightened by a preset PWM signal. A plant side frequency change part 205 changes the frequency of the PWM signal to be an integral multiple of the refresh rate. A plant side flicker determination part 206 determines whether a flicker of the screen displayed by the back light part lightened by the changed PWM signal and the screen display part has run out. A plant side integral multiple storage part 208 makes the integral multiple of the refresh rate to be stored in a predetermined storage medium 209 when the flicker of the screen runs out, and is used for a lighting control of the back light part of the operation panel.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an operation panel manufacturing apparatus, an operation panel, a display device, an operation panel manufacturing method, and a display device display method.

  In recent years, large color TFT liquid crystal operation panels have been used for operation panels of printers, copiers, and multifunction peripherals, and there is a technique for improving the operability of the operation panels.

  On the other hand, a TFT liquid crystal needs a backlight for improving visibility, and in recent years, an LED is used as a light source of the backlight. There are two types of LED lighting methods.

  One is a conventional DC lighting method. In this method, the light amount is adjusted by the current value of the constant current by DC driving the constant current. The other is a PWM lighting method in which a constant current is pulse-driven in a time division manner. In this PWM lighting method, the light amount is adjusted by adjusting the time division duty ratio of a constant current, and the frequency of the duty ratio becomes the lighting frequency of the backlight. This PWM lighting method is widely used because it has good characteristics even at low light intensity.

  However, when the PWM lighting method is controlled, the frequency of the duty ratio interferes with the rewrite refresh rate (frequency) of the TFT liquid crystal screen, causing a problem of flickering on the screen. Further, the frequency range in which the flickering of the screen occurs differs depending on each operation panel due to variations in the components of the TFT liquid crystal operation panel. In other words, even if it is a frequency range where the flicker phenomenon does not occur in one operation panel, it is a frequency range where the flicker phenomenon occurs in the other operation panel, and PWM lighting is uniformly applied to all manufactured operation panels. There is a problem that the frequency of the duty ratio of the method cannot be set.

  In order to improve such flickering of the screen, there is a method of setting the frequency of the duty ratio to an integral multiple of the screen rewriting refresh rate (frequency). Japanese Patent Laid-Open No. 2010-200481 (Patent Document 1) generates a duty signal that does not synchronize with the vertical synchronization frequency of the liquid crystal display device in order to prevent beat noise or flickering that occurs on the screen of the liquid crystal display device. Techniques for making them disclosed are disclosed. This prevents the phenomenon of flickering in the TFT liquid crystal.

JP 2010-200481 A

  However, in the conventional method for preventing flickering of the screen, as described above, due to individual differences in the components of the operation panel, variation in the integral multiple of the screen rewrite refresh rate frequency is seen, and it is uniformly a constant integral multiple. There is a problem that cannot be selected. Moreover, in the technique described in Patent Document 1, it is necessary to separately provide a sensor or the like in order to specify the duty signal, and there is a problem that it is not a simple method and costs high.

  Accordingly, the present invention has been made to solve the above-described problems, and an operation panel manufacturing apparatus and an operation panel that can prevent flickering of the screen even if there are individual differences in the components of the operation panel. An object of the present invention is to provide a display device, a method for manufacturing an operation panel, and a display method for the display device.

  An operation panel manufacturing apparatus according to one aspect of the present invention includes a factory-side screen rewriting unit, a factory-side lighting control unit, a factory-side frequency changing unit, a factory-side flickering determining unit, and a factory-side integer multiple storage unit. . The factory side screen rewriting unit periodically rewrites the screen of the screen display unit of the operation panel at a preset refresh rate. The factory-side lighting control unit turns on the backlight unit of the operation panel with a PWM signal having a preset frequency and duty ratio in a PWM lighting method. The factory-side frequency changing unit changes the frequency of the PWM signal so as to be an integral multiple of the refresh rate. The factory-side flicker determination unit determines whether the flicker of the screen displayed by the backlight unit that is turned on by the changed PWM signal and the screen display unit has disappeared. The factory-side integer multiple storage unit stores an integer multiple of the refresh rate when the screen flicker disappears in a predetermined storage medium, and uses it for lighting control of the backlight unit of the operation panel.

  When the screen flickers, the factory-side frequency changing unit changes the frequency of the PWM signal so as to be an integer multiple of the refresh rate that is larger than the integer multiple of the refresh rate before the change.

  The factory-side frequency changing unit, when there is flickering of the screen, calculates the next largest integer value of the integer value of the refresh rate before the change, up to the multiplication value obtained by multiplying the refresh rate by the calculated integer value The frequency of the PWM signal is changed.

  An operation panel according to one aspect of the present invention includes a screen display unit, a backlight unit, and a storage medium. The screen display unit displays a screen that is periodically rewritten at a preset refresh rate. The backlight unit is turned on by a PWM signal and a PWM signal having a preset frequency and duty ratio. The storage medium stores an integer multiple of the refresh rate when the screen flickers disappear, and is used for lighting control of the backlight unit with a PWM signal having a frequency of the integral multiple.

  A display device according to one aspect of the present invention includes a screen display unit, a backlight unit, a main body side screen rewriting unit, and a main body side lighting control unit. The screen display unit displays a screen. The backlight unit is turned on by a PWM signal and a PWM signal having a preset frequency and duty ratio. The main body screen rewriting unit periodically rewrites the screen at the refresh rate. The main body side lighting control unit lights the backlight unit with a PWM signal having a frequency that is an integral multiple of the refresh rate based on an integer multiple of the refresh rate when the screen flickers disappear.

  An operation panel manufacturing method according to one aspect of the present invention includes a factory-side screen rewriting step, a factory-side lighting control step, a factory-side frequency changing step, a factory-side flicker determination step, and a factory-side integer multiple storage step. . In the factory-side screen rewriting step, the screen of the screen display unit of the operation panel is periodically rewritten at a preset refresh rate. The factory-side lighting control step uses a PWM lighting method to light the backlight portion of the operation panel with a PWM signal having a preset frequency and duty ratio. In the factory side frequency changing step, the frequency of the PWM signal is changed to be an integral multiple of the refresh rate. In the factory-side flicker determination step, it is determined whether or not the flicker of the screen displayed by the backlight unit that is turned on by the changed PWM signal and the screen display unit is eliminated. In the factory-side integer multiple storage step, an integer multiple of the refresh rate when the screen flickers disappear is stored in a predetermined storage medium, and used for lighting control of the backlight unit of the operation panel.

  A display method for a display device according to an aspect of the present invention is a display method for a display device including a screen display unit and a backlight unit, and includes a main body side screen rewriting step, a main body side lighting control step, . In the main body side screen rewriting step, the screen is periodically rewritten at the refresh rate. In the main body side lighting control step, the backlight unit is turned on with a PWM signal having an integer multiple of the refresh rate based on an integer multiple of the refresh rate when the screen flickering disappears.

  According to the operation panel manufacturing apparatus, operation panel, display device, operation panel manufacturing method, and display device display method of the present invention, even if there are individual differences in the components of the operation panel, flickering of the screen is prevented. Is possible.

1 is a conceptual diagram illustrating an overall configuration of a multifunction machine including an operation panel according to the present invention. FIG. 2 is a functional block diagram of a multifunction machine according to an embodiment of the present invention. It is a flowchart for showing the execution procedure of the embodiment of the present invention. The figure (FIG. 4A) which shows an example of the manufacturing factory in the case of carrying out the lighting inspection of the operation panel in embodiment of this invention, and the figure which shows an example of the manufacturing factory in the case of connecting the operation panel in embodiment of this invention (figure) 4B).

  Embodiments of an operation panel manufacturing device, an operation panel, a display device, an operation panel manufacturing method, and a display device display method according to the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. . In addition, the following embodiment is an example which actualized this invention, Comprising: The thing of the character which limits the technical scope of this invention is not. In addition, the alphabet “S” added in front of the numbers in the flowcharts means steps.

  Hereinafter, an image forming apparatus using an operation panel will be described as an example of an operation panel according to an embodiment of the present invention. Note that the image forming apparatus according to the present invention corresponds to, for example, a multifunction peripheral (MFP) having functions such as a facsimile, a copy, a scanner, and a printer.

  As shown in FIG. 1, when receiving a print job setting condition from the user via the operation unit 101, the multifunction device 100 drives each unit such as an image reading unit, an image forming unit, a conveyance unit, and a fixing unit. Provide print jobs. The operation unit 101 is provided with an operation panel. The operation panel is usually provided with a screen display unit for displaying a screen and a backlight unit for irradiating the screen display unit with light. The screen display unit is composed of, for example, a TFT liquid crystal. The main body of the multifunction device 100 includes a main body side screen rewriting unit that rewrites (switches) the screen of the screen display unit at a predetermined cycle, and a main body side lighting control unit that controls lighting of the backlight unit by a PWM lighting method. Is provided.

  Although not shown, the control circuit of the multifunction peripheral 100 including the operation panel includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD (Hard Disk Drive), and each drive unit. Corresponding driver is connected by internal bus.

  The CPU of the multifunction machine 100 uses, for example, a RAM as a work area, executes a program stored in a ROM, HDD, etc., and receives data, instructions, signals, instructions, etc. from the driver based on the execution results. And controls the operation of each drive unit related to the execution of the print job. Further, for each unit (shown in FIG. 2) to be described later other than the drive unit, the CPU implements each unit by executing each program. A ROM, a RAM, an HDD, and the like store programs and data for realizing each unit described below.

  Next, the configuration and execution procedure according to the embodiment of the present invention will be described with reference to FIGS. Here, a manufacturing factory where the main body of the multifunction peripheral 100 and the operation unit 101 are separately manufactured is assumed. When the operation unit 101 is manufactured in a manufacturing factory, as shown in FIG. 2, a screen display unit 201 (for example, TFT liquid crystal) and a backlight unit 202 are mounted below the operation panel 200 of the operation unit 101. The In this state, the manufacturer performs a lighting inspection of the operation unit 101.

  First, as shown in FIGS. 2 and 4A, the manufacturer electrically connects the screen display section 201 of the operation panel 200 to the factory-side screen rewriting section 203, which is a dedicated jig circuit of the manufacturing factory. A factory-side lighting control unit 204 that is a dedicated jig circuit is electrically connected to the backlight unit 202 of the panel 200. Then, when the manufacturer instructs the factory-side screen rewriting unit 203 to display a screen, the factory-side screen rewriting unit 203 periodically rewrites the screen of the screen display unit 201 at a preset refresh rate (see FIG. 3: S101).

  Here, the method of rewriting by the factory side screen rewriting unit 203 is not particularly limited. For example, the factory-side screen rewriting unit 203 acquires reference screen data corresponding to the instruction from a predetermined memory, and uses the acquired screen data as a preset refresh rate (see FIG. 4A). Periodically transmitted to the screen display unit 201 at a frequency (for example, 40 Hz). The refresh rate (1 / T1) means the number of times the screen is updated per second (Hz), and the reciprocal of the refresh rate corresponds to the refresh rate period T1. The higher the refresh rate, the more stable the screen display.

  Next, when the manufacturer instructs the factory-side lighting control unit 204 to turn on, the factory-side lighting control unit 204 uses the PWM lighting method, and the backlight unit 202 is configured with a PWM signal having a preset frequency and duty ratio. Turn on (FIG. 3: S102).

  Here, there is no limitation in particular in the method which the factory side lighting control part 204 makes it light. For example, the factory-side lighting control unit 204 generates a PWM signal having a predetermined frequency (for example, 50 Hz) and a duty ratio D (for example, 20%) from a predetermined PWM signal generation unit, and uses the PWM signal as a backlight unit. It transmits to 202 periodically. The reciprocal of the PWM signal (frequency 1 / T2) corresponds to the period T2 of the PWM signal, and the duty ratio D means the ratio of the period during which the ON signal of the PWM signal continues in the predetermined period T2. When the duty ratio D increases, the amount of lighting light increases, and when the duty ratio D decreases, the amount of lighting light decreases.

  Further, when the manufacturer instructs the factory-side frequency changing unit 205 of the dedicated jig circuit to change the frequency of the PWM signal, the factory-side frequency changing unit 205 sets the frequency of the PWM signal to an integer multiple of the refresh rate. (FIG. 3: S103).

  Here, there is no limitation in particular in the method which the factory side frequency change part 205 changes. For example, the factory-side frequency changing unit 405 first calculates a division value (1.25) obtained by dividing the frequency (50 Hz) of the PWM signal input to the backlight unit 202 by the refresh rate (40 Hz). The smallest integer value (for example, 2) that is larger than the calculated division value is calculated. Then, the factory-side frequency change unit 405 calculates a multiplication value (80 Hz) obtained by multiplying the calculated integer value by the refresh rate as a frequency of the PWM signal after the change, and multiplies the frequency (40 Hz) of the PWM signal. Change to the value (80 Hz).

  Now, when the factory-side frequency changing unit 205 completes the change, the factory-side flicker determining unit 206 of the dedicated jig circuit notifies the fact, and the factory-side flicker determining unit 206 that has received the notification notifies the changed It is determined whether or not the flickering of the screen displayed by the backlight unit 202 that is lit by the PWM signal and the screen display unit 201 has disappeared (FIG. 3: S104).

  Here, there is no limitation in particular in the method which the factory side flicker determination part 206 determines. For example, a predetermined sensor 207 (for example, a dedicated light amount sensor, a dedicated illuminometer) is provided in advance on the screen displayed by the screen display unit 201 and the backlight unit 202, and the factory-side flicker determination unit 206 is provided. However, the sensor 207 is monitored to determine whether or not the screen flickers.

  This flickering of the screen is, for example, a stripe pattern that appears on the screen, and is a characteristic phenomenon that appears only in the PWM lighting method. For example, it is considered to be caused by fluctuations in raw materials, glass substrates, surface electrodes, transistor response speeds, and the like constituting each part. In this determination, for example, the manufacturer may determine whether or not the screen is flickering while viewing the screen with the naked eye, and input an instruction to that effect to the flicker determination unit 206.

  As a result of the determination, if the screen flicker does not disappear, in other words, if there is flicker on the screen (FIG. 3: S104 NO), the factory-side flicker determination unit 206 notifies the factory-side frequency change unit 205 to that effect. Then, returning to S103, the factory-side frequency changing unit 205 further changes the frequency of the PWM signal so that it becomes an integer multiple of the refresh rate larger than the integer multiple of the refresh rate before the change (FIG. 3). : S103).

  Here, when the factory-side frequency changing unit 206 changes the frequency of the PWM signal again, for example, the factory-side frequency changing unit 206 calculates the next larger integer value (3) after the integer value (2) of the refresh rate before the change. Then, a multiplication value (120 Hz) obtained by multiplying the calculated integer value (3) by the refresh rate (40 Hz) is calculated as a frequency of a new PWM signal. Then, the factory side frequency changing unit 206 changes the frequency (40 Hz) of the PWM signal to the multiplication value (120 Hz). Thereby, the frequency of the PWM signal can be increased stepwise, and the frequency of the PWM signal with the least lighting frequency and no flickering of the screen can be searched.

  On the other hand, if the result of the determination in step S104 is that there is no flicker in the screen (FIG. 3: S104 YES), the factory-side flicker determination unit 406 notifies the factory-side integer multiple storage unit 208 to that effect. Receiving the notification, the factory-side integer multiple storage unit 208 stores an integer multiple (for example, 6) of the refresh rate when the flickering of the screen disappears in a predetermined storage medium 209, and the backlight of the operation panel 200 It is used for lighting control of the unit 202 (FIG. 3: S105).

  Here, there is no limitation in particular in the method which the factory side integer multiple memory | storage part 208 memorize | stores. For example, when a predetermined storage medium 209 (nonvolatile memory) is built in the operation unit 101 in advance, the factory-side integer multiple storage unit 208 stores the integer multiple (6) in the nonvolatile memory 209. . On the other hand, when the non-volatile memory 209 does not exist in the operation unit 101, the factory-side integer multiple storage unit 208 outputs, for example, a storage medium (paper, barcode, etc.) corresponding to the integer multiple (6). Then, the manufacturer may own or manage this, or it may be attached to each operation unit 101.

  Now, when the factory-side integer multiple storage unit 208 completes the storage, the factory-side screen rewriting unit 203 notifies that fact, and the factory-side screen rewriting unit 203 that has received the notification displays the screen display of the screen display unit 201. Stop (FIG. 3: S106). Also, the factory-side integer multiple storage unit 208 notifies the factory-side lighting control unit 204 to that effect, and the factory-side lighting control unit 204 that has received the notification turns off the backlight unit 202 that is turned on (FIG. 3). S107). Thereby, the lighting inspection of the operation unit 101 in the manufacturing factory is completed.

  When the operation unit 101 for which the lighting inspection is completed is transported to the connection process to the main body of the multi-function peripheral 101 separately assembled in the manufacturing factory, the manufacturer, as shown in FIGS. Is connected to the main body (FIG. 3: S108).

  Then, when the manufacturer turns on the power of each part and inputs a screen rewriting instruction to the main body side screen rewriting unit 210 of the multifunction peripheral 100 using a dedicated jig circuit, the main body side screen rewriting unit 210 The screen of the display unit 201 is periodically rewritten at a predetermined refresh rate (FIG. 3: S109). Further, when the manufacturer inputs a lighting control instruction to the main body side lighting control unit 211 of the multifunction peripheral 100 using a dedicated jig circuit, the main body side lighting control unit 211 is stored in the storage medium 209. The integer multiple (6) is read, and the backlight unit 202 is turned on with a PWM signal having a frequency (240 Hz) that is an integral multiple of the refresh rate (FIG. 3: S110). As a result, the MFP 100 can display the screen with no screen flickering. In particular, in the present invention, even when there are variations in the components of the operation unit 101 and manufacturing variations, an optimal integer multiple is calculated individually in the lighting inspection, and this is used when the MFP 100 and the operation unit 101 are connected. Therefore, the flickering of the screen can be eliminated for each operation unit 101 regardless of individual differences of the operation units 101. After the manufacturer confirms the display of the screen in the multi-function device 100, the power of each unit is turned off and the above connection process is completed.

  Note that the above is a case where the storage medium 209 is built in the operation unit 101 in advance. However, if the storage medium 209 is not built in, for example, in S110, the manufacturer uses a dedicated jig circuit. Is used to read the integer multiple (6) from a separately output storage medium (paper, barcode, etc.) and input it to the main body side lighting control unit 211. Thereby, the main body side lighting control unit 211 lights the backlight unit 202 with a PWM signal having a frequency (240 Hz) that is an integer multiple of the refresh rate based on the input integer multiple (FIG. 3: S110).

  In the operation panel 200 according to the embodiment of the present invention, the case where the operation panel 200 is applied to the multifunction peripheral 100 using the operation panel has been described. However, a display device (operation unit, operation device), an image forming apparatus, and an image having an operation panel are described. Even when applied to a processing device, an image processing device, an image display device, a processing device, etc., the same effects can be obtained.

  In the embodiment of the present invention, an operation panel may be used. That is, the operation panel according to the present invention stores the screen display unit 201, the backlight unit 202, and an integer multiple of the refresh rate when the screen flicker disappears, and the PWM signal having the frequency of the integer multiple And a storage medium 209 used for lighting control of the backlight unit. Even this has the same effect. The operation panel according to the present invention is obtained when a user purchases a commercially available operation panel, mounts it on a display device, and adjusts and uses the PWM signal based on an integral multiple of the storage medium 209. It has the effects of the invention and is the implementation of the present invention.

  In the embodiment of the present invention, a display device may be used. That is, the display device according to the present invention is based on the screen display unit 201, the backlight unit 202, the main body screen rewriting unit 210, and the integer multiple of the refresh rate when the screen flickers disappear. A main body side lighting control unit 211 for lighting the backlight unit with a PWM signal having a frequency of. Even this has the same effect. Note that the storage device 209 may be provided in the display device.

  In the embodiment of the present invention, a display method of a display device may be used. That is, the display method according to the present invention is based on an integer multiple of a main body side screen rewriting step for periodically rewriting the screen at the refresh rate and an integer multiple of the refresh rate when the screen is no longer flickering. And a main body side lighting control step of lighting the backlight unit with a PWM signal having a frequency of. Even this has the same effect.

  The operation panel according to the present invention may be manufactured by the above-described manufacturing apparatus or manufacturing method, or may be manufactured by other means. The same applies to the display device according to the present invention.

  In the embodiment of the present invention, the manufacturing plant of the operation panel 200 or the multi-function peripheral is configured to include each unit. However, a program that realizes each unit is stored in a storage medium, and the storage medium is provided. It doesn't matter. In the configuration, the apparatus is made to read the program, and the apparatus realizes the respective units. In that case, the program itself read from the recording medium exhibits the effects of the present invention. Furthermore, it is also possible to provide a method for storing the steps executed by each unit in a hard disk.

  As described above, the operation panel manufacturing apparatus, the operation panel, the display device, the operation panel manufacturing method, and the display device display method according to the present invention can be used not only for a multi-function machine using the operation panel but also for a copying machine, a printer, and a display Operation panel manufacturing apparatus, operation panel, display apparatus, operation panel manufacturing method, and display apparatus that can prevent flickering of the screen even if there are individual differences in the operation panel components. This is an effective display method.

DESCRIPTION OF SYMBOLS 100 MFP 101 Operation part 200 Operation panel 201 Screen display part 202 Back light part 203 Factory side screen rewriting part 204 Factory side lighting control part 205 Factory side frequency change part 206 Factory side flicker determination part 207 Sensor 208 Factory side integer multiple storage part 209 Storage medium 210 Main body side screen rewriting section 211 Main body side lighting control section

Claims (7)

A factory-side screen rewriting unit that periodically rewrites the screen of the screen display unit of the operation panel at a preset refresh rate;
A factory-side lighting control unit that lights the backlight unit of the operation panel with a PWM signal having a preset frequency and duty ratio in a PWM lighting method,
A factory-side frequency changing unit that changes the frequency of the PWM signal to be an integral multiple of the refresh rate;
A factory-side flicker determination unit that determines whether the flicker of the screen displayed by the backlight unit that is lit by the changed PWM signal and the screen display unit has been eliminated;
An integer multiple of the refresh rate when the screen flicker disappears is stored in a predetermined storage medium, and is used for lighting control of the backlight unit of the operation panel, and a factory-side integer multiple storage unit;
An apparatus for manufacturing an operation panel. The factory-side frequency changing unit changes the frequency of the PWM signal so as to be an integer multiple of a refresh rate larger than an integer multiple of the refresh rate before the change when the screen flickers. The manufacturing apparatus as described. The factory-side frequency changing unit, when there is flickering of the screen, calculates the next largest integer value of the integer value of the refresh rate before the change, up to the multiplication value obtained by multiplying the refresh rate by the calculated integer value The manufacturing apparatus according to claim 2, wherein the frequency of the PWM signal is changed. A screen display unit for displaying a screen periodically rewritten at a preset refresh rate;
In the PWM lighting system, a backlight unit that is lit by a PWM signal having a preset frequency and duty ratio;
Storing an integer multiple of the refresh rate when the flickering of the screen disappears, a PWM signal having a frequency of the integer multiple, and a storage medium used for lighting control of the backlight unit;
An operation panel comprising: A screen display for displaying the screen;
In the PWM lighting system, a backlight unit that is lit by a PWM signal having a preset frequency and duty ratio;
A body-side screen rewriting unit that periodically rewrites the screen at the refresh rate;
Based on the integral multiple of the refresh rate when the screen flicker disappears, with the PWM signal of the integral multiple frequency, the main body side lighting control unit that lights the backlight unit,
A display device comprising: A factory-side screen rewriting step of periodically rewriting the screen of the screen display section of the operation panel at a preset refresh rate;
A factory-side lighting control step of lighting the backlight unit of the operation panel with a PWM signal having a preset frequency and duty ratio in a PWM lighting method,
A factory-side frequency changing step for changing the frequency of the PWM signal to be an integral multiple of the refresh rate;
A factory side flicker determination step for determining whether the flicker of the screen displayed by the backlight unit that is lit by the changed PWM signal and the screen display unit has been eliminated;
An integer multiple of the refresh rate when the screen flicker disappears is stored in a predetermined storage medium, and is used for lighting control of the backlight portion of the operation panel, and is stored on the factory side integer multiple,
A method for manufacturing an operation panel, comprising: A screen display for displaying the screen;
A display method of a display device comprising a backlight unit that is lit by a PWM signal of a preset frequency and a duty ratio in a PWM lighting method,
A body side screen rewriting step of periodically rewriting the screen at the refresh rate;
Based on the integral multiple of the refresh rate when the flickering of the screen disappears, with the PWM signal of the integral multiple frequency, the main body side lighting control step of lighting the backlight unit,
A display method comprising: