JP2000137565A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a third person from arbitrarily adjusting a screen by invalidating the operation of a specified key based on the depression of a prescribed key which is simultaneous with the supply of power. SOLUTION: The operation of a specified key is invalidated based on the depression of a prescribed key which is simultaneous with the supply of power. Relating to the device, a control part 11 detects driving current Icc from a power circuit 17 and initializes various flags if it judges the depression of a power key 8. The control part 11 judges whether the prescribed key is depressed at the same time as the supply of the power key 8 (a menu key and a selection key are simultaneously depressed, for example). Relating to the device, a key locking state flag in a storage part 15 can be changed when the menu key and the selection key are depressed at the same time as the depression of the power key 8. When the flag is in an on-state, a screen adjusting processing is not executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device.

[0002]

2. Description of the Related Art Usually, an LCD (LiquidCryst) is used.
A display device such as an alDisplay monitor is provided with a plurality of keys for adjusting the screen such as the contrast of the display screen of the display device and the width of the display screen (for example, Nikkei BP's Nikkei BP). Electronics, No. 7-13, 1998, p. 43).

[0003]

When such a display device is used in an exhibition hall or the like for display, there is a possibility that a third party may operate a key for adjusting the display device without permission.

It is conceivable to provide a lid in order to avoid such an operation by a third party, but this is not necessarily an effective method because the third party can easily open and close the lid.

[0005]

The display device of the present invention is characterized in that a specific key operation is not accepted by pressing a key simultaneously with turning on the power.

[0006]

FIG. 1 is an external perspective view of a display device 1 to which the present invention is applied.

A display device 1 shown in FIG. 1 includes a display unit 2 composed of, for example, an LCD, a menu key 3, a select key 4,
A screen adjustment key group 7 including an UP key 5 and a DOWN key 6 and a power key 8 are provided.

Each key of the key group 7 is used for screen adjustment.

In the apparatus of this embodiment, when the user adjusts the screen, the user first presses the power key 8 to start up the display device 1.

Then, when the menu key 3 is pressed, the display unit 2 displays six adjustment items of the horizontal position of the screen, the vertical position of the screen, the vertical width of the screen, the horizontal width of the screen, the flicker of the screen, and the screen contrast. Names are displayed in order from the top.

Then, by operating the UP key 5 or the DOWN key 6, the cursor is moved to a desired item name, and then the select key 4 is pressed to execute the adjustment mode of the adjustment item to be adjusted. You.

FIG. 2 is a block diagram showing a circuit configuration of the device of the present embodiment. The display device 1 comprises a main circuit section 9 and a power supply section 1.
It consists of 0.

In the main circuit section 9, a control section 11 controls each circuit.

The screen adjustment key group 7 sends a key press signal corresponding to a press operation of the keys 3 to 6 to the control unit 11.

The signal conversion unit 12 includes a video amplifier for performing amplification, AD conversion, image processing, and the like of an image signal received from a personal computer or the like via the first connector 13, and an ADC (A / D).
analog Digital Converter), an image processing IC, and the like.

The display unit 2 is connected to the signal conversion unit 12 via the second connector 14 and displays an image signal received from the signal conversion unit 12 via the second connector 14.

The storage unit 15 is, for example, a rewritable EEPROM (Electrica) that does not require a backup.
llyErasableProgrammableRo
m), and stores data on whether or not a key lock state is described later.

The power supply unit 10 has an AC power supply 16 and a power supply circuit 17 connected thereto. The circuit 17 has a smoothing circuit composed of, for example, a diode bridge, and the power supply key 8 is pressed. And an AC current from the AC power supply 16 to a DC current Icc suitable for driving each circuit of the main circuit section 9.
And supplies it to each of the circuits.

FIG. 3 is a flowchart showing the operation of the first embodiment, and the operation will be described below based on this flowchart.

In step S1, the control unit 11 determines whether or not the power key 8 has been pressed by detecting the drive current Icc from the power supply circuit 17, and if it is determined that the power key 8 has been pressed, the process proceeds to step S2. Proceed.

In step S2, the control unit 11 initializes various flags. For example, a clock time by a clock circuit (not shown) is initialized (for example, 00:00
Minutes).

In the following S3 step, the control unit 11 determines whether or not a predetermined key is pressed (for example, the menu key 3 and the select key 4 are simultaneously pressed) at the same time as the power key 8 is turned on in the S1 step. I do.

More specifically, when the control unit 11 detects a pressing signal of the menu key 3 and the select key 4 from the key group 7 when detecting the drive current Icc from the power supply circuit 17, the process proceeds to step S4. Otherwise, the process proceeds to step S7.

In step S4, the control unit 11 searches the storage unit 15 for a flag indicating whether the key is locked or not.
If it is determined that the flag is on, S
The process proceeds to step S5, and if it is determined that the flag is off, the process proceeds to step S6.

In step S5, the control unit 11 controls the storage unit 15 to turn off the key lock state flag stored in the storage unit 15, and proceeds to step S7.

In step S6, the control unit 11 controls the storage unit 15 to turn on the key lock state flag stored in the storage unit 15, and proceeds to step S7.

In step S7, the control unit 11 determines that the menu key 3 of the screen adjustment key group 7 has been pressed after the power key 8 is turned on.
The process proceeds to step S8, and if it is determined that the key 3 has not been pressed, the process proceeds to step S10.

In step S8, the control unit 11 sets the S
It is determined whether or not the key is locked as in the case of step 4. If it is determined that the key is locked, the process returns to step S7. If it is determined that the key is not locked, the process proceeds to step S9.

In step S9, the control section 11 performs the above-described screen adjustment processing, and thereafter returns to step S7.

In step S10, the control unit 11 determines whether or not the power is off by detecting whether or not the drive current Icc is supplied from the power supply circuit 17, and determines whether or not the power is off. However, if it is determined that the power is off, the process proceeds to step S11, and the driving is stopped.

On the other hand, if it is determined that the power is on, the process returns to step S7.

As described above, in the first embodiment, when the power key 8 is pressed and the menu key 3 and the select key 4 are pressed simultaneously, the key lock state flag in the storage unit 15 can be changed. When this flag is ON, the screen adjustment processing is not executed.

The storage unit 15 stores the EE that does not need a backup.
Since the display is constituted by the PROM, the power is turned off in the key lock state of the display device, and the key lock state is maintained even if the power is turned on again thereafter.

FIG. 4 is a flowchart showing the operation of the second embodiment, and the operation will be described below based on this flowchart.

In step S21, the control section 11 determines whether or not the power key 8 has been pressed in the same manner as in step S1. If it is determined that the key 8 has been pressed, the control section 11 proceeds to step S22.

In step S22, the control section 11 initializes various flags and turns off the key lock flag of the storage section 15.

In step S23, similarly to step S3, the control unit 11 determines whether or not a predetermined key is pressed at the same time as turning on the power key 8, and if it is determined that the predetermined key is pressed, Proceeds to step S24. On the other hand, if it is determined that the predetermined key has not been pressed, the process proceeds to step S25.

In step S24, the control unit 11 controls the storage unit 15 to turn on the key lock state flag stored in the storage unit 15, and then proceeds to step S2.
The process proceeds to five steps.

The processing of the controller 11 in steps S25 to S29 is the same as the processing in steps S7 to S11 of the first embodiment, and a description thereof will be omitted.

As described above, in the display device of the second embodiment, the key lock state can be set only when the menu key 3 and the select key 4 are pressed at the same time when the power key 8 is pressed. Therefore, the key lock state can be controlled each time the power is turned on regardless of the state when the power was last turned off. In this embodiment, only the pressing of the menu key 3 is invalidated in the key lock state. All key inputs except for the key input 8 may be invalidated.

[0041]

According to the present invention, there is an effect that a third party is prevented from adjusting the screen without permission.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a display device according to an embodiment.

FIG. 2 is a block diagram illustrating a circuit configuration of the display device according to the present embodiment.

FIG. 3 is a flowchart showing the operation of the first embodiment.

FIG. 4 is a flowchart showing the operation of the second embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 display device 2 display unit 3 menu key 4 select key 5 UP key 6 DOWN key 7 screen adjustment key group 8 power key 9 main circuit unit 10 power supply unit 11 control unit 12 signal conversion unit 13 first connector 14 second connector 15 Storage unit 16 AC power supply 17 Power supply circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Matsumoto 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture F-term (reference) in Sanyo Electric Co., Ltd. 5B020 AA15 BB10 CC12 DD02 GG57 GG63

Claims (3)

[Claims] 1. A display device, wherein a specific key operation is invalidated based on a predetermined key depression at the same time as power-on. 2. The display device according to claim 1, wherein said display device has a backup unnecessary memory capable of storing information indicating that a key input is invalid. 3. The display device according to claim 2, wherein the display device turns off the power once, turns on the power again, and cancels the key input invalid state.