JP2009089366A - Image forming apparatus, and display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and display method capable of shortening the time until displaying an initial picture on a display unit during power-on. <P>SOLUTION: In a case where a reset signal sent from a main control unit is in a reset cancel state, in power-on, where reset processing due to main control unit has been completed, a liquid crystal display (LCD) control unit 1211 sends out an address signal indicating an address for reading display data stored in a display data storage unit 1212, a trigger signal indicating timing to read the display data, a validity signal indicating that display of the display data is valid, and a display timing signal indicating timing to display the display data. On the basis of the trigger signal, display data corresponding to the address signal are read from the display data storage unit 1212 and on the basis of a validity period signal and display timing signal, an LCD 122 displays the read display data thereon. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a display method.

  In recent years, multi-functional image processing apparatuses include a display unit that combines a liquid crystal display and a touch panel in order to improve a user interface. In such an image processing apparatus, when the power is turned on, the main control unit executes an initial process with a high priority, and then executes an initial screen display process on the display unit. Accordingly, when it takes time for the initial screen to be displayed on the display unit after the power is turned on, there is a problem that the user cannot determine whether or not the image processing apparatus is operating normally.

  In order to solve such a problem, an image processing apparatus including a control unit that operates independently of a main control unit is disclosed (see Patent Document 1). In such an image processing apparatus, by performing display processing on the display unit with a control unit different from the main control unit when the power is turned on, the initial screen can be displayed without waiting for the end of the initial processing in the main control unit. Become.

Japanese Patent Laid-Open No. 2003-141501

  However, in the technique described in Patent Document 1, even when the display process is performed on the display unit by a control unit different from the main control unit, the initial process of the control unit is performed similarly to the main control unit when the power is turned on. If it is not executed, display on the display unit cannot be performed, and there is a problem that it takes a predetermined time until the display on the display unit is started.

  The present invention has been made in view of the above, and an object of the present invention is to provide an image forming apparatus and a display method capable of shortening the time until the initial screen is displayed on the display unit when the power is turned on. .

In order to solve the above-described problems and achieve the object, the invention according to claim 1 includes a display data storage means for storing display data, and a reset signal sent from the main control section when the power is turned on. An address signal indicating an address for reading the display data stored in the display data storage means, and a trigger signal indicating a timing for reading the display data when the reset processing is in a reset release state indicating that the reset process has been completed; Display control means for sending an effective period signal indicating that display of the display data is valid; a display timing signal indicating timing for displaying the display data; and the trigger signal sent from the display control means Display data reading means for reading the display data corresponding to the address signal from the display data storage means A display means on the basis of the said effective period signal sent from the display control means and said display timing signal, and displays the display data read by the display data reading means,
It is characterized by providing.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the display data reading unit is configured to generate the address signal at a timing at which a level of the trigger signal sent from the display control unit changes. The display data corresponding to is read from the display data storage means.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the display unit is configured such that the valid period signal indicates that the display of the display data is valid. The display data is displayed at a timing at which the level of the display timing signal changes.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the display control unit further includes a determination unit that determines a logical level input from an input terminal. Whether to control to display the display data stored in the display data storage means or to display the display data sent from the main control means according to the logical level determined by the determination means It is characterized by switching to either.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the display control unit further includes a determination unit that determines a logical level input from an input terminal. Is characterized in that, among the display data stored in the display data storage means, control is performed so as to read display data corresponding to the logical level determined by the determination means.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, the determining unit determines the size of the display unit according to a logical level input from the input terminal. And

  According to a seventh aspect of the present invention, in the image forming apparatus according to the fifth aspect, the determination unit determines a display color to be displayed on the display unit according to a logical level input from the input terminal. It is characterized by.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the fifth aspect, the determination unit reads the display data from the display data storage unit according to a logic level input from the input terminal. It is characterized in that an address to start is determined.

  According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the fourth to eighth aspects, the input terminal can be controlled from the main control unit by one input terminal, and the other input terminals. The terminal is a mechanical switch whose logic level can be set by an operator.

  According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the first to ninth aspects, the display data stored in the display data storage unit is controlled by the main control unit. It further comprises switching means for enabling rewriting, and rewriting means for rewriting the display data stored in the display data storage means under the control of the main control unit by the switching means.

  According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the first to tenth aspects, the display data storage unit is detachable.

  According to a twelfth aspect of the present invention, there is provided a display method executed by the image forming apparatus, wherein the display control means receives a reset signal sent from the main control unit when the power is turned on and the reset process of the main control unit is completed. An address signal indicating an address for reading the display data stored in the display data storage means for storing the display data, and a trigger signal indicating the timing for reading the display data, A display control step for transmitting an effective period signal indicating that the display of the display data is valid; a display timing signal indicating a timing for displaying the display data; and a display data reading means for transmitting from the display control step. Based on the triggered signal, the display data corresponding to the address signal is stored in the display data storage means. A display data reading step for reading, and a display step for displaying the display data read by the display data reading step based on the effective period signal and the display timing signal sent from the display control step. It is characterized by having.

  According to the present invention, when the power is turned on, the display data read from the display data storage unit is displayed on the display unit without waiting for the end of the initial processing of the main control unit in response to the reset signal sent from the main control unit. Therefore, it is possible to shorten the time until the initial screen is displayed on the display unit when the power is turned on.

  Exemplary embodiments of an image forming apparatus and a display method according to the present invention are explained in detail below with reference to the accompanying drawings. The present invention is not limited to these embodiments.

(First embodiment)
A first embodiment will be described with reference to the accompanying drawings. In this embodiment, as an image forming apparatus, a copy function, a print function, a scanner function, and an input image (an original image read by the scanner function or an image input via a printer or a network) are transmitted via the network. This is an example in which a so-called MFP (Multi Function Peripheral) that combines functions and the like is applied.

  First, a configuration example of a multifunction machine to which the present invention is applied will be described. FIG. 1 is a block diagram illustrating a configuration of a multifunction peripheral according to the first embodiment. The multifunction peripheral 100 according to the present embodiment includes a main control unit 110, a display unit 120, an operation unit 130, a scanner unit 140, and a printer unit 150.

  The main control unit 110 further includes a SoC (System On Chip) 111, a ROM (Read Only Memory) 112, a RAM (Randam Access Memory) 113, a LAN (Local Area Network) I / F 114, and a USB (Universal Serial Bus). ) I / F 115.

  The SoC 111 controls the entire MFP 100, and includes a CPU (Central Processing Unit) core and image processing and motor control necessary for the MFP 100, image control for a printer, and a general-purpose interface network with a PC (Personal Computer). It incorporates various functions such as control. When SoC is not used, a configuration using a CPU, MPU (micro processing unit, CPU core including peripheral functions such as an interrupt controller) and ASIC (application specific integrated circuit) may be used.

  The ROM 112 stores a main control program for the multifunction machine 100. The RAM 113 temporarily accumulates data in the process of executing the program by the SoC 111, or accumulates image data in the process of performing image processing. Further, an interface with a PC or the like is taken by the LAN I / F 114 or the USB I / F 115.

  The display unit 120 and the operation unit 130 are physically integrated. The display unit 120 further includes an LCD (Liquid Crystal Display) controller 121 and an LCD 122. The LCD controller 121 is a liquid crystal display controller and controls the LCD 122. The LCD 122 is a simple matrix type liquid crystal display. Instead of the LCD, a liquid crystal display of an active matrix type liquid crystal display called TFT (Thin Film Transistor) may be used. The detailed configuration and processing of the LCD controller 121 will be described later.

  The operation unit 130 further includes a key control unit 131 and a key unit 132. The key unit 132 accepts user operations, and the key control unit 131 controls the key unit 132, using a general-purpose serial communication interface such as EIA (Electro. Nic Industries Alliance) -232, or an interface such as USB, It connects to the SoC 111 of the main control unit 110 and notifies information corresponding to the pressed key.

  The configurations of the LCD controller 121 and the LCD 122 will be described in more detail. FIG. 2 is a block diagram showing the configuration of the LCD controller and the LCD.

  The LCD controller 121 further includes an LCD control unit 1211, a display data storage unit 1212, a reset input unit 1213, an input terminal state determination unit 1214, a main control unit I / F 1215, an LCD I / F 1216, and a buffer memory 1217. The LCD control data storage unit 1218 and the clock unit 1219 are provided.

  The LCD control unit 1211 controls to read display data from the display data storage unit 1212 and display the read display data on the LCD 122 when the level of the reset signal indicates a reset release state. Specifically, the LCD 122 is controlled by hardware called a sequencer circuit, and the sequencer circuit is incorporated in the LCD controller 1211.

  Here, the reset release state is a state indicating that the reset process executed when the main control unit 110 is turned on is finished, and the level of the reset signal is High. Further, when the main control unit 110 is performing the reset process, the reset is valid and the level of the reset signal is Low. Further, the LCD control unit 1211 controls the LCD 122 according to a control signal sent from the main control unit 110 when the initial processing of the main control unit 110 is completed.

  The display data storage unit 1212 stores display data displayed when the MFP 100 is turned on. Specifically, the display data storage unit 1212 uses a non-volatile memory such as an EPROM (Erasable Programmable Read Only Memory), and an interface with the LCD controller 121 is an SPI (Serial Peripheral Interface) or I2C (Inter Integrated Circuit). ) Or a general-purpose bus interface used for an address bus and a data bus may be used. The display data storage unit 1212 may be a non-volatile memory capable of writing data by write access like read access, such as a flash memory.

  The reset input unit 1213 is an interface that receives a reset signal sent from the main control unit 110. The reset signal received by the reset input unit 1213 is input to the LCD control unit 1211.

  The input terminal state determination unit 1214 selects a function by determining a low level or high level input terminal state input from the main control unit 110 and the input terminal. As a function that can be selected, it is selected whether to display the display data stored in the data storage unit 1212 on the LCD 122 or to display the display data on the LCD 122 under the control of the main control unit. In addition, by using a plurality of input terminals, an LCD size for displaying display data is set. The logical level of the input terminal can be determined by physically fixing it to a power supply level (High level) or a GND (ground) level (Low level). In addition, by using a mechanical switch for the input terminal, the logic level can be easily changed. The mechanical switch may be a switch in which a short pin is inserted into a terminal block such as a dip switch, in addition to a switch such as a slide switch or a rotary switch.

  FIG. 3 is an explanatory diagram illustrating an example of a function to be selected according to the input terminal state. As shown in FIG. 3, when the input terminal state is In1 is High, display is performed by the LCD controller, and when In1 is Low, display control is performed by the main control unit.

  The main control unit I / F 1215 is an interface for inputting a control signal sent from the main control unit 110 to the LCD control unit 1211. Specifically, the main control unit I / F 1215 may use a serial interface such as SPI or USB, or a general-purpose interface used in the address bus and data bus such as ROM and RAM. Further, when the distance of the interface is long, interface conversion such as LVDS (Low Voltage Differential Signaling) may be performed in order to reduce noise and to ensure an interface.

  The LCD I / F 1216 is an interface for inputting the LCD control signal sent from the LDC control unit 1211 to the LCD 122.

  The buffer memory 1217 stores display data for rewriting when the display on the LCD 122 does not change. The buffer memory 1217 has a memory capacity for one screen or two screens of the normal LCD 122 (liquid crystal display). Since the liquid crystal drive (voltage application) of the LCD 122 needs to be rewritten at regular intervals when the screen contents are not switched, a display buffer memory having such a memory capacity is built in or attached externally. . Note that if the driver of the LCD 122 (the one that drives the LCD) has a memory function, the display buffer memory may not be provided.

  The LCD control data storage unit 1218 stores data for controlling the LCD 122. The clock unit 1219 generates a clock signal.

  Next, an LCD display process performed by the MFP 100 configured as described above will be described. FIG. 4 is a flowchart showing an LCD display processing procedure performed by the LCD control unit.

  First, the MFP 100 is turned on. The LCD control unit 1211 determines whether or not the reset signal sent from the main control unit 110 via the reset input unit 1213 is in a reset release state (step S401). If it is determined that the reset signal is not in the reset release state, that is, the reset is in a valid state (step S401: No), the process returns to step S401 and repeats until the reset signal enters the reset release state.

  If it is determined that the reset signal is in the reset release state (step S401: Yes), the LCD control unit 1211 initializes the LCD 122 (step S402). Note that some LCDs 122 (liquid crystal displays) do not require initial setting in order to operate. In the case of the present embodiment, it is only necessary to control a predetermined liquid crystal display. Therefore, a sequencer circuit (combining sequential circuit) serving as control data is incorporated in advance in the LCD controller 121 and is not controlled by the main control unit 110. The LCD controller 110 itself performs initial setting control of the liquid crystal display while the reset signal enters the reset release state.

  Next, the LCD control unit 1211 reads the display data stored in the display data storage unit 1212 and accumulates it in the buffer memory 1217 (step S403). The LCD control unit 1211 controls the display data stored in the buffer memory 1217 to be transferred to the LCD 122 for display (step S404). The LCD 122 displays, for example, a single color full screen display, blinking of a single color full screen display, and a cursor flowing from left to right.

  The input terminal state determination unit 1214 determines whether the function selected in accordance with the level of the input terminal that has been input is a screen display at startup (display by the LCD controller) or main control unit control (step S405). . Specifically, the determination is made based on whether a high level or a low level is input to the input terminal In1. Here, when the initial processing in the main control unit 110 after powering on the multifunction peripheral 100 is not completed, the level is high. When the initial processing in the main control unit 110 is completed, the level is low. .

  That is, the SoC 111 of the main control unit 110, after reset release, performs vector data read, which is a basic startup operation as the SoC 111, data read (instruction fetch) specified by a vector address, instruction analysis, instruction execution, Processing such as write back of the execution result (writing to the register or RAM of the SoC 111) is repeated, and necessary initialization is performed according to the program. Therefore, until the processing is completed, the screen display at the time of activation is repeatedly performed according to the determination in step S405.

  If it is determined that the level of the input terminal is the screen display at startup (High level) (step S405: screen display at startup), the process returns to step S404 to display the screen at startup. When it is determined that the level of the input terminal is the main control unit control (Low level) (step S405: main control unit control), display data is received from the main control unit 110 (step S406). Specifically, the LCD control unit 1211 receives display data sent from the main control unit 110 via the main control unit I / F 1215.

  The LCD control unit 1211 accumulates the received display data in the buffer memory 1217 (step S407). The LCD control unit 1211 controls the display data stored in the buffer memory 1217 to be transferred to the LCD 122 for display (step S408). Note that the data in the display data memory may be used directly without using the buffer memory.

  As described above, after the reset process of the main control unit 110 is completed, the display data is not displayed on the LCD 122 without waiting for the time until the initial process in the main control unit 110 is completed and without the control from the main control unit 110. Therefore, the time until the initial screen of the LCD 122 when the power is turned on can be shortened.

  Since the LCD controller 121 that performs control for displaying display data on the LCD 122 is hardware, the display data can be displayed at high speed. In addition, since a dedicated CPU and peripheral circuits are not required as the display unit, the cost can be reduced.

  Next, processing timing of each unit corresponding to the flowchart described in FIG. 4 will be described. FIG. 5 is an explanatory diagram showing an example of a time chart from when the power is turned on until display data is displayed on the LCD.

  First, phase 0 is before the power is turned on to the multi-function device 100. The power source is also at the low level of the reset signal, and neither the main controller 110 nor the LCD controller 121 is operating. Next, in phase 1, power is turned on. As a result, the power supply level shifts from Low to High. The reset signal is at a low level, and neither the main control unit 110 nor the LCD controller 121 is in normal operation yet.

  Phase 2 is a reset period of the main control unit 110. In phase 1, the power supply is in a stable state at the high level. The reset signal becomes a high level at the time when the phase 2 ends, and indicates a reset release state in which the reset period has ended. In this phase 2, initialization is performed. The LCD controller 121 initializes an internal register of the LCD controller 121 (generally holding an electrical level called a flip-flop), and stabilizes oscillation of a clock that is an operation clock of the LCD controller 121. Used to wait. Further, the level of the input terminal of the LCD controller 121 is determined at this point because the input terminal is connected to the power supply or GND (ground, ground). Note that when the reset of the LCD controller 121 itself is completed, the LCD controller 121 may send a reset signal at a timing different from that of the main control unit 110 without waiting for the reset process of the main control unit 110 to end.

  Phase 3 is an initial processing period of the main control unit 110. In phase 3, both the power supply and the reset signal are at a high level. The main control unit 110 executes initial processing. The LCD controller 121 executes an initial screen display process because the reset signal is at a high level indicating a reset release state. Thus, the initial screen can be displayed on the LCD 122 without waiting for the end of the initial processing of the main control unit 110.

  Phase 4 is an operation period of the main control unit 110. In phase 4, both the power supply and the reset signal are at a high level. The main control unit 110 can operate normally and sends a control signal to the LCD controller 121 for control. The LCD controller 121 is controlled by a control signal from the main control unit 110.

  Conventionally, the process of displaying the initial screen on the LCD 122 cannot be started unless the reset process (phase 2) and the initial process (phase 3) of the main control unit 110 are completed. However, in this embodiment, since the LCD controller 121 displays the initial screen regardless of the control of the main control unit 110, the initial screen is displayed without waiting for the period of the initial processing (phase 3) of the main control unit 110. This can shorten the time until the initial screen is displayed.

  Next, a more specific signal flow among the LCD control unit 1211, the display data storage unit 1212, and the LCD 122 and the timing of each signal command will be described. FIG. 6 is an explanatory diagram showing an example of the flow of signals in the LCD control unit, the display data storage unit, and the LCD. FIG. 7 is an explanatory diagram schematically showing the timing of each signal.

  As shown in FIG. 6, the LCD control unit 1211 receives a clock signal (ck) sent from the clock unit 1219 and a reset signal (reset) sent from the main control unit 110. As indicated by 71 in FIG. 7, at the timing when the reset signal becomes High level, the LCD control unit 1211 sends a ROM address signal (rom-ad) and ROM read trigger signal (rom-ck) to the display data storage unit 1212. Is sent out.

  The LCD control unit 1211 sends the display data at the address indicated by the ROM address signal stored in the display data storage unit 1212 to the LCD 122 at the rise timing of the ROM read trigger signal.

  In the LCD control unit 1211, an LCD display signal (lcd-ck) indicating the timing for displaying the display data and an effective period signal (lcd-cs) indicating the effective period of the display data at the timing when the reset signal becomes High level. Is sent to the LCD 122. The LCD 122 displays the received display data at the rising timing of the LCD display signal while the valid period signal is valid (Low level).

  Next, another embodiment will be described. In the embodiment described above, the logic level of the input terminal input to the input terminal state determination unit 1214 is used only to determine whether display control is performed by the main control unit 110 or display by the LCD controller. Various functions can be further selected by combining the levels of the three input terminals.

  As functions that can be selected, an LCD size for displaying display data, an LCD display color, a memory call address, and the like can be set. FIG. 8 is an explanatory diagram showing an example of the LCD size that can be selected depending on the input terminal state. As shown in FIG. 8, for example, when all of the input terminal states In1, In2, and In3 are high, 320 * 240 is selected as the LCD size.

  As described above, since the LCD controller 121 can perform control corresponding to the size of the LCD 122 according to the combination of the levels of the input terminal states, it is easy to expand the model to a plurality of multifunction machines equipped with different types of LCDs 122. Can be done.

  Next, switching of colors displayed on the LCD 122 will be described. FIG. 9 is an explanatory diagram showing an example of the display color of the LCD that can be selected according to the input terminal state. As shown in FIG. 9, for example, when all of the input terminal states In1, In2, and In3 are high, blue is selected as the LCD display color.

  Thus, since the LCD controller 121 can control the display color of the LCD 122 according to the combination of the levels of the input terminal states, the display color can be easily changed and the program for changing the display color can be rewritten. Work etc. can be reduced.

  Next, switching of display data displayed on the LCD 122 will be described. FIG. 10 is an explanatory diagram showing an example of the display data address of the LCD that can be selected according to the input terminal state. As shown in FIG. 10, for example, when all of the input terminal states In1, In2, and In3 are High, reading is selected from the initial screen memory address 1000 as display data. In this case, it is possible to display an initial screen with a high degree of freedom by storing display data of different words for each read address or display data in different languages.

  In this way, the display data displayed on the LCD 122 can be changed by changing the read address of the memory by the LCD controller 121 according to the combination of the levels of the input terminal states. For example, the language to be displayed is changed. As a result, the destination of the multifunction device 100 can be easily deployed.

  In the embodiment described above, various functions are selected depending on the states of the three input terminals. However, the number of input terminals is not limited to three, and may be one, two, four or more. Good.

(Second Embodiment)
A second embodiment will be described with reference to the accompanying drawings. With respect to the configuration example of the LCD controller to which the present invention is applied, a different part from the first embodiment will be described. The other parts are the same as those in the first embodiment, so the description is omitted with reference to the above description. FIG. 11 is a block diagram illustrating the configuration of the LCD controller and the LCD according to the second embodiment.

  The LCD controller 221 according to the present embodiment further includes an LCD control unit 1211, a display data storage unit 2212, a reset input unit 1213, an input terminal state determination unit 1214, a main control unit I / F 1215, and an LCD I / F 1216. A buffer memory 1217, an LCD control data storage unit 1218, a clock unit 1219, a bus switching unit 2211, and a memory I / F 2213.

  Here, the LCD control unit 1211, the reset input unit 1213, the input terminal state determination unit 1214, the main control unit I / F 1215, the LCD I / F 1216, the buffer memory 1217, the LCD control data storage unit 1218, the clock Since the configuration and function of the unit 1219 are the same as those in the first embodiment, description thereof is omitted.

  The display data storage unit 2212 has the same function and configuration as the display data storage unit 1212 described in the first embodiment, but is installed outside the LCD controller 221.

  The memory I / F 2213 serves as an interface with the display data storage unit 2212. The memory I / F 2213 may be a general-purpose interface in addition to a serial interface such as I2C or SPI. The display data storage unit 2212 is accessed regardless of the control from the main control unit 110 so that the LCD controller 221 displays the display data at the time of activation on the LCD 122.

  The bus switching unit 2211 accesses a certain register of the LCD controller 221 to switch the bus switch for accessing the display data storage unit 2212 from the main control unit 110, and the control line to the display data storage unit 2212 is the main line. Control is possible with a control signal from the control unit 110.

  As described above, the control to the display data storage unit 2212 by the bus switching unit 2211 can be controlled from the main control unit 110, so that the liquid crystal display data can be rewritten via the main control unit 110 in the manufacturing process. Can be used. Further, the display data storage unit 2212 is mounted on the IC socket, so that the display data of the liquid crystal display at the time of startup can be easily changed by replacing the memory for storing the liquid crystal display data.

  As described above, the present invention has been described using the first embodiment, the second embodiment, and the modifications. However, various modifications or improvements can be added to the above-described embodiments. Note that the configurations and functions described in the first embodiment, the second embodiment, and the modifications described above can be freely combined.

  In the above-described embodiment, the multifunction device has been described as an example. However, the present invention is not limited to the multifunction device, and can be applied to an apparatus that performs initial screen display processing, such as a copier, a facsimile, and a printer. .

1 is a block diagram illustrating a configuration of a multifunction machine according to a first embodiment. It is a block diagram which shows the structure of a LCD controller and LCD. It is explanatory drawing which shows an example of the function selected according to an input terminal state. It is a flowchart which shows the LCD display processing procedure which an LCD control part performs. It is explanatory drawing which shows an example of the time chart until display data is displayed on LCD after power-on. It is explanatory drawing which shows an example of the flow of a signal in a LCD control part, a display data storage part, and LCD. It is explanatory drawing which shows the timing of each signal typically. It is explanatory drawing which shows an example of LCD size which can be selected by an input terminal state. It is explanatory drawing which shows an example of the display color of LCD which can be selected by an input terminal state. It is explanatory drawing which shows an example of the address of the display data of LCD which can be selected by an input terminal state. It is a block diagram which shows the structure of the LCD controller concerning 2nd Embodiment, and LCD.

Explanation of symbols

100 MFP 110 Main Control Unit 111 SoC
112 ROM
113 RAM
114 LAN I / F
115 USB I / F
120 Display unit 121 221 LCD controller 122 LCD
130 Operation unit 131 Key control unit 132 Key unit 140 Scanner unit 150 Printer unit 1211 LCD control unit 1212 2212 Display data storage unit 1213 Reset input unit 1214 Input terminal state determination unit 1215 Main control unit I / F
1216 LCD I / F
1217 Buffer memory 1218 LCD control data storage unit 1219 Clock unit 2211 Bus switching unit 2213 Memory I / F

Claims (12)

Display data storage means for storing display data;
An address for reading the display data stored in the display data storage means when the reset signal sent from the main control unit at power-on is in a reset release state indicating that the reset process of the main control unit is completed An address signal indicating the display data, a trigger signal indicating the timing for reading the display data, a valid period signal indicating that the display of the display data is valid, and a display timing signal indicating the timing for displaying the display data Display control means for
Display data reading means for reading the display data corresponding to the address signal from the display data storage means based on the trigger signal sent from the display control means;
Display means for displaying the display data read by the display data reading means based on the valid period signal and the display timing signal sent from the display control means;
An image forming apparatus comprising:   The display data reading unit reads the display data corresponding to the address signal from the display data storage unit at a timing when the level of the trigger signal sent from the display control unit changes. Item 2. The image forming apparatus according to Item 1.   The display means displays the display data at a timing when a level of the display timing signal changes when the valid period signal indicates that the display of the display data is valid. The image forming apparatus according to claim 1 or 2. A discriminating means for discriminating a logic level inputted from the input terminal;
The display control means controls to display the display data stored in the display data storage means or displays the display data sent from the main control means according to the logical level determined by the determination means. The image forming apparatus according to claim 1, wherein the image forming apparatus is switched to any one of the control modes. A discriminating means for discriminating a logic level inputted from the input terminal;
The display control means controls the display data stored in the display data storage means so as to read display data corresponding to the logical level determined by the determination means. 4. The image forming apparatus according to any one of items 3.   The image forming apparatus according to claim 5, wherein the determination unit determines a size of the display unit according to a logical level input from the input terminal.   The image forming apparatus according to claim 5, wherein the determination unit determines a display color to be displayed on the display unit according to a logical level input from the input terminal.   The image forming apparatus according to claim 5, wherein the determination unit determines an address at which reading of the display data is started from the display data storage unit according to a logic level input from the input terminal. .   The input terminal is a mechanical switch in which one input terminal can be controlled from a main control unit, and the other input terminal is a mechanical switch whose logic level can be set by an operator. The image forming apparatus according to claim 1. Switching means for enabling rewriting of the display data stored in the display data storage means under the control of the main control unit;
The rewriting means for rewriting the display data stored in the display data storage means under the control of the main control unit by the switching means, further comprising: a rewriting means. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein the display data storage unit is detachable. A display method executed by an image forming apparatus,
When the display control means is in a reset release state indicating that the reset processing of the main control section is completed when the reset signal sent from the main control section when the power is turned on, it is stored in the display data storage means for storing display data Further, an address signal indicating an address for reading the display data, a trigger signal indicating a timing for reading the display data, a valid period signal indicating that the display of the display data is valid, and the display data are displayed. A display control step for transmitting a display timing signal indicating timing;
A display data reading means for reading the display data corresponding to the address signal from the display data storage means based on the trigger signal sent from the display control step;
A display step for displaying the display data read by the display data reading step based on the effective period signal and the display timing signal sent from the display control step;
A display method characterized by comprising:

Images