JP6344198B2 - Electrical equipment - Google Patents

Description

  The present invention relates to an electric device including a liquid crystal display (LCD) as a display unit.

  A display unit is provided in an operation unit of an electric device such as a copying machine or an MFP. A liquid crystal display (LCD) used as a display unit is often provided as an LCD module enclosed with glass or the like together with an IC that drives the LCD (see, for example, Patent Document 1). The LCD module includes an IC power supply terminal, a ground terminal, a display control signal terminal, a booster circuit power supply terminal, a reset terminal, and the like as interface terminals.

JP 2006-78680 A

  However, since the LCD module is not provided with an output terminal that outputs an output signal to the control unit that controls the LCD module, the control unit must grasp the state of the IC in the LCD module from the outside. I can't. Therefore, when the IC in the LCD module is locked for some reason, there is a problem that it can be restored only by turning on / off the power.

  This invention is made | formed in view of this point, The place made into the objective is to provide the electric equipment which can grasp | ascertain the state in an LCD module from the outside.

In order to solve such a problem, the electrical device of the present invention is an electrical device including an LCD module including a liquid crystal display and an LCD driver for driving the liquid crystal display, and a user operates to input an instruction. An operation unit that performs power supply, an internal power supply circuit that supplies power to the LCD module, a booster circuit that is connected to a boosting power supply terminal of the LCD module that boosts a voltage supplied from the internal power supply circuit, and the boosting power supply The voltage detection circuit for detecting the voltage value of the terminal and the contrast is once changed using the contrast control command at the latest refresh timing when the operation unit is operated by the user, and the contrast is restored at the next refresh timing or later. The voltage detection circuit detects the contrast change. Was that the voltage value is determined whether the change, wherein the LCD driver and a determining lock state judgment means whether or not the lock.
Furthermore, in the electric device of the present invention, the operation unit may be an operation button different from the position input unit integrated with the LCD module .
Further, in the electrical device of the present invention, the lock state determination means changes the contrast in a plurality of times stepwise, and the voltage value detected by the voltage detection circuit at the darkest contrast and the lightest contrast. It may be determined whether or not the LCD driver is locked based on a change from the voltage value detected by the voltage detection circuit.

  According to the present invention, the state of the LCD driver in the LCD module can be grasped from the outside, and the LCD driver that has been locked by the control unit can be restored.

1 is a schematic cross-sectional view showing an internal configuration of an embodiment of an electric device according to the present invention. It is a block diagram which shows schematic structure of the electric equipment shown in FIG. It is a block diagram of the principal part which drives the LCD module shown in FIG.

Next, embodiments of the present invention will be specifically described with reference to the drawings.
The electrical apparatus according to the present embodiment is a copying machine 1 using an electrophotographic system. Referring to FIG. 1, a document reading unit 2, a document feeding unit 3, a main body unit 4, and an operation unit 6 are provided. I have. The document feeding unit 3 is disposed on the upper part of the document reading unit 2, and the document reading unit 2 is disposed on the upper part of the main body unit 4, and between the document reading unit 2 and the main body unit 4. A paper discharge space 40 is formed. Although the present embodiment has been described with reference to the copying machine 1, it goes without saying that a scanner, a decoder, and the like are included.

  The operation unit 6 is provided with a touch panel 61 and operation buttons 62. The user operates the operation unit 6 and inputs an instruction to perform various settings of the copying machine 1 and execute various functions such as a scanning operation and image formation. The touch panel 61 is configured to display the status of the copier 1, display the image forming status and the number of copies, and perform various settings such as functions such as double-sided printing and black-and-white reversal, magnification setting, and density setting. The operation buttons 62 include a start button for instructing start of scanning operation and image formation, a stop button for instructing stop of scanning operation and image formation, a reset button used when various settings of the copying machine 1 are set to a default state, A numeric keypad for inputting the number of prints and the like is provided.

  The document reading unit 2 includes a light source and an image sensor, guides light from the light source to the image surface of the document MS, and guides reflected light from the image surface to an image sensor such as a CCD sensor, and a platen glass 22. And a document reading slit 23. The scanner 21 is fixed to a toothed belt 26 spanned between the motor 24 and the pulley 25, and the image of the original MS on which the scanner 21 is placed on the platen glass 22 by driving the motor 24. The image is moved along the surface, and the image surface of the document MS is scanned. The platen glass 22 is an original table made of a transparent member such as glass. The document reading slit 23 is a slit formed in a direction orthogonal to the document transport direction by the document feeder 3.

  When reading the document MS placed on the platen glass 22, the document MS placed on the platen glass 22 is moved in one line in the main scanning direction while moving the scanner 21 along the platen glass 22 in the sub-scanning direction. Image data is acquired by scanning each time, and the acquired image data is output to the main body unit 4. When reading the document MS conveyed by the document feeding unit 3, the scanner 21 is moved to a position facing the document reading slit 23, and the document is conveyed by the document feeding unit 3 through the document reading slit 23. In synchronization with the operation, the document MS is read to acquire image data, and the acquired image data is output to the main unit 4.

  The document feeding unit 3 includes a document placement unit 31, a document discharge unit 32, and a document transport mechanism 33. The original MS placed on the original placement portion 31 is sequentially fed out one by one by the original conveyance mechanism 33 and conveyed to a position facing the original reading slit 23, and then discharged to the original discharge portion 32. The document feeding unit 3 is configured to be retractable and functions as a platen cover that opens and closes the platen glass 22. When the document feeding unit 3 is lifted upward and opened, the upper surface of the platen glass 22 is opened. be able to.

  The main body unit 4 includes a recording unit 5 that records on the recording paper P by an electrophotographic process, and includes a paper feed cassette 41, a paper feed roller 42, a paper transport path 43, transport rollers 44 and 45, and a discharge roller. 46. The paper feed roller 42, the transport rollers 44 and 45, and the discharge roller 46 function as a transport unit that transports the recording paper P. The recording paper P stored in the paper feed cassette 41 is fed one by one to the paper transport path 43 by the paper feed roller 42 and transported to the recording unit 5 by the transport roller 44. Then, the recording paper P on which recording has been performed by the recording unit 5 is discharged to the paper discharge space 40 by the discharge roller 46.

  The recording unit 5 includes a photosensitive drum 51, a charger 52, an optical scanning unit 53, a developing unit 54, a transfer roller 55, a fixing unit 56, and a cleaning unit 57. In the image formation by the recording unit 5, first, the surface of the photosensitive drum 51 is uniformly charged by the charger 52, and based on the image data read by the document reading unit 2, the optical scanning unit 53 performs the image reading of the photosensitive drum 51. An electrostatic latent image is formed by scanning the surface. Next, the electrostatic latent image formed on the surface of the photosensitive drum 51 is developed by the developing unit 54 to form a toner image. The toner image formed on the surface of the photosensitive drum 51 is transferred to the recording paper P while the recording paper P fed from the paper feed cassette 41 passes through the nip portion between the photosensitive drum 51 and the transfer roller 55. The The toner image transferred to the recording paper P is thermally fixed to the recording paper P while passing through the fixing unit 56.

  FIG. 2 is a block diagram showing a schematic configuration of the copying machine 1. The document reading unit 2, the document feeding unit 3, the transport unit (feed roller 42, transport rollers 44 and 45, discharge roller 46), the recording unit 5, and the operation unit 6 are connected to the control unit 7. The operation is controlled by 7. In addition, an image processing unit 8 and a storage unit 9 are connected to the control unit 7.

  The control unit 7 is an information processing unit such as a microcomputer including a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The ROM stores a control program for controlling the operation of the copying machine 1. The control unit 7 reads out a control program stored in the ROM and develops the control program in the RAM, thereby controlling the entire apparatus according to predetermined instruction information input from the operation unit 6.

  The image processing unit 8 is a unit that performs predetermined image processing on the image data. For example, image improvement processing such as enlargement / reduction processing, gradation adjustment, and density adjustment is performed.

  The touch panel 61 of the operation unit 6 is an integrated display of the LCD module 10 that is a display device and a position input unit 63 that is an input device. Specify which displayed item element is specified.

  Referring to FIG. 3, the LCD module 10 includes a liquid crystal display (LCD) 11 and an LCD driver 12 that is an IC for driving the LCD 11. The LCD 11 and the LCD driver 12 are provided in a state of being enclosed with glass or the like. ing.

  The drive voltage Vcc of the LCD module 10 is generated and input by the internal power supply circuit 13 connected to an external power supply. The drive voltage Vcc is a voltage for driving the LCD driver 12. The LCD 11 is driven by a voltage obtained by boosting the drive voltage Vcc by the booster circuit 14 connected to the LCD module 10. Also. A voltage detection circuit 15 for detecting the voltage of the boosting power supply terminal to which the booster circuit 14 is connected is provided, and the voltage value detected by the voltage detection circuit 15 is input to the control unit 7.

  The LCD driver 12 in the LCD module 10 drives the LCD 11 based on the display control signal received from the control unit 7 to display various information. The display control signal includes various display control commands such as a contrast control command in addition to the display data. The LCD driver 12 restarts itself when a reset signal is input from the control unit 7.

The control unit 7 determines whether or not the LCD driver 12 in the LCD module 10 is locked at a predetermined timing. Hereinafter, this lock determination operation will be described in detail.
In the display of the LCD module 10, dots are displayed by applying a voltage to the liquid crystal of the LCD 11, and the contrast changes according to the voltage applied to the liquid crystal. Therefore, when the contrast is changed, the voltage of the boosting power supply terminal, which is a voltage for driving the LCD 11, changes. The contrast can be changed at an arbitrary timing as long as the LCD driver 12 is accessible.

  Therefore, the control unit 7 changes the contrast once by using the contrast control command at the refresh timing of the LCD module 10 that repeatedly accesses the LCD driver 12 at a constant period, and then changes the contrast at the subsequent refresh timing. Revert. The controller 7 determines whether or not the voltage value detected by the voltage detection circuit 15 has changed with the change in contrast. When the amount of change in the voltage value accompanying the change in contrast is equal to or greater than a preset threshold, the control unit 7 determines that the LCD driver 12 is not locked and continues display control as it is.

  On the other hand, when the amount of change in the voltage value accompanying the change in contrast is less than a preset threshold value, the control unit 7 determines that the LCD driver 12 is locked, and sends a reset signal to the LCD driver 12. Output. As a result, the LCD driver 12 is restarted and the locked state is released.

  Note that the contrast change timing (refresh timing) and the contrast change amount (the fluctuation amount of the voltage value of the boosting power supply terminal to which the booster circuit 14 is connected) are the timing and change amount that are not flickering with human eyes. It is preferable to set.

  Also, whether or not the voltage value detected by the voltage detection circuit 15 at the darkest contrast and the voltage value detected by the voltage detection circuit 15 at the lightest contrast are changed by changing the contrast stepwise. You may comprise so that it may determine. In this case, a change in voltage value can be determined based on a large change amount while preventing flickering.

  The timing for performing the lock determination operation is arbitrary, but it is preferable to perform it at the latest refresh timing when the operation button 62 or the position input unit 63 is operated by the user. In other words, in a state where no operation is performed, the user may notice a change in contrast, but even if the contrast changes with the operation, it is recognized as a series of displays accompanying the operation. Further, it is more preferable that the timing for performing the lock determination operation is performed at the latest refresh timing when the operation button 62 is operated by the user. In this case, since the user's line of sight is directed toward the operation button 62, there is an advantage that the user hardly notices a change in contrast.

As described above, according to the present embodiment, the copying machine 1 includes the LCD module 10 including the LCD 11 and the LCD driver 12, the internal power supply circuit 13 that supplies power to the LCD module 10, and the internal The contrast of the booster circuit 14 connected to the booster power supply terminal of the LCD module 10 that boosts the voltage supplied from the power supply circuit 13, the voltage detection circuit 15 that detects the voltage value of the booster power supply terminal, and the LCD 11 is changed. And a lock state determination means (control unit 7) for determining whether or not the LCD driver 12 is locked based on a change in the voltage value detected by the voltage detection circuit 15.
With this configuration, the state of the LCD driver 12 in the LCD module 10 (whether or not the LCD driver 12 is locked) can be grasped by the voltage value of the boosting power supply terminal, and the control unit 7 enters the locked state. The stuck LCD driver 12 can be restored. As a result, it is possible to save the user from having to turn on / off the power.

  Furthermore, according to the present embodiment, the control unit 7 that is a lock state determination unit changes the contrast of the LCD 11 at the refresh timing of the LCD module 10.

Furthermore, according to the present embodiment, the control unit 7 that is a lock state determination unit changes the contrast stepwise a plurality of times, and the voltage value detected by the voltage detection circuit 15 at the darkest contrast, It may be determined whether or not the LCD driver 12 is locked based on a change from the voltage value detected by the voltage detection circuit 15 when the contrast is low.
With this configuration, it is possible to determine a change in voltage value based on a large change amount while preventing flickering.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Copier 2 Original reading part 3 Original feeding part 4 Main body part 5 Recording part 6 Operation part 7 Control part 8 Image processing part 9 Memory | storage part 10 LCD module 11 Liquid crystal display (LCD)
DESCRIPTION OF SYMBOLS 12 LCD driver 13 Internal power supply circuit 14 Booster circuit 15 Voltage detection circuit 21 Scanner 22 Platen glass 23 Document reading slit 24 Motor 25 Pulley 26 Toothed belt 31 Document loading part 32 Document discharge part 33 Document conveyance mechanism 40 Paper discharge space 41 Feed Paper cassette 42 Paper feed roller 43 Paper transport path 44, 45 Transport roller 46 Discharge roller 51 Photosensitive drum 52 Charging device 53 Optical scanning unit 54 Development unit 55 Transfer roller 56 Fixing unit 57 Cleaning unit 61 Touch panel 62 Operation button 63 Position input unit

Claims (3)

An electrical device comprising an LCD module comprising a liquid crystal display and an LCD driver for driving the liquid crystal display,
An operation unit that is operated by a user and inputs instructions;
An internal power supply circuit for supplying power to the LCD module;
A booster circuit connected to a booster power supply terminal of the LCD module for boosting a voltage supplied from the internal power supply circuit;
A voltage detection circuit for detecting a voltage value of the boosting power supply terminal;
At the latest refresh timing when the operation unit is operated by the user, the contrast is temporarily changed using a contrast control command, and the contrast is restored again at the next refresh timing and the voltage is changed according to the contrast change. An electrical apparatus comprising: a lock state determination unit that determines whether or not the LCD driver is locked by determining whether or not a voltage value detected by a detection circuit has changed . The electric device according to claim 1 , wherein the operation unit is an operation button different from a position input unit integrated with the LCD module .   The lock state determining means changes the contrast a plurality of times stepwise, the voltage value detected by the voltage detection circuit at the darkest contrast, and the voltage detected by the voltage detection circuit at the lightest contrast. 3. The electric device according to claim 2, wherein whether or not the LCD driver is locked is determined based on a change from the value.

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