JP2002215107A - Power source control device for equipment using microcomputer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To turn off a power source of a color LCD according to a specified sequence even if a power source of the whole equipment is directly turned off, in the equipment mounted with the color LCD. SOLUTION: A printer 1 turns off the power source of the color LCD 9 by using two kinds of signals of a system reset control signal 17 for controlling to reset the whole printer system and an LCD reset control signal 19 for controlling to reset the power source of the color LCD 9. The printer 1 completely brings the whole system into OFF state by turning off a power source VDD specified to be turned off after starting the system reset control signal 17 to turn off a power source VEE which is specified to be turned off first and also turn off the power sources of the systems other than the color LCD 9, waiting until status data have been written, and then switching off the LCD reset control signal 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control device for a color liquid crystal display, and more particularly to a power supply control for turning off the power supply of a color liquid crystal display.

[0002]

2. Description of the Related Art There are a wide variety of devices equipped with a display for displaying the state of the device and the like. In recent years, liquid crystal displays have been developed because of their advantages of being lightweight, thin, and low in power consumption. It is thought to be. Liquid crystal displays are broadly classified into a monochrome display type (hereinafter referred to as monochrome LCD) and a color display type (hereinafter referred to as color LCD). LCDs are increasingly mounted.

[0003]

In a color LCD, a sequence for turning on and off a power supply is specified.

For example, VDD (+5 V) and VEE (-3
2V) Color LCD driven by two power supplies
Stipulates that VDD is turned on before or simultaneously with VEE as a power-on sequence. On the other hand, as a sequence for turning off the power supply, as shown in FIG. 1, first, VEE is turned off, and the time length during which the voltage applied by VEE drops to -1.5 V is controlled to 70 msec or more, and VEE is set to -1. After the voltage becomes 5 V, VDD is turned off, the applied voltage by VDD is reduced to 4 V by applying 0 msec or more, and the logic is stopped. When the logic is stopped, the time length for reducing the applied voltage by VDD to 0.5 V is set to 50 msec. It is regulated to control within. That is, this color LCD
When power is turned off, VEE is turned off first, then VDD is turned off, and a time lag (hereinafter, power supply turn-off time lag) X is provided for 70 msec or more.

[0005] In a device equipped with a color LCD, it is necessary to turn on and off the power supply of the color LCD in the sequence defined as described above. In particular, the turn-off sequence must be strictly observed from the viewpoint of preventing liquid crystal damage.

[0006] However, the turn-off sequence can be reliably maintained if the power is turned off by the power switch of the color LCD. However, the power plug of the device is pulled out from the commercial power source or the battery is removed, and the entire device is directly turned off. Even when the power supply is turned off, it must be protected.

Accordingly, an object of the present invention is to provide a color LCD in a device equipped with a color LCD while maintaining a prescribed sequence even if the power of the entire device is directly turned off.
It is to turn off the power supply of the CD.

[0008]

According to the present invention, a power control device for a microcomputer-based device uses a power consuming unit that requires a predetermined end procedure when power is cut off, and uses the power consuming unit. A data processing unit for executing data processing and terminating the process with another termination procedure when the power is turned off, and terminating the processing with another termination procedure when the power is turned off; and a power consuming unit connected to the main power supply. And a power supply unit for supplying a predetermined power to the data processing unit, and a power supply control device of a microcomputer-based device for turning on / off the power supply by directly turning on / off the primary side of the power supply unit. There is a first reset function that occurs when the primary side of the power supply unit is shut off, and a predetermined time has elapsed since the first reset function occurred. Is and a second reset function occurs after the, when the first reset function occurs,
A predetermined termination procedure is started, and the predetermined termination procedure is completed by the occurrence of the second reset function.

In a preferred embodiment, the predetermined time is reserved in advance as a time for the data processing unit to execute another termination procedure.

In another preferred embodiment, the power supply control device of the microcomputer-based device further includes another power consumption unit different from the power consumption unit, and when the first reset function is generated, Power supply to other power consuming units is cut off.

[0011] In another preferred embodiment, at least one or both of the first reset function and the second reset function are realized as a reset signal.

[0012] In still another preferred embodiment, at least one or both of the first reset function and the second reset function are realized as commands issued from the data processing unit.

In another preferred embodiment, the data processing section controls a printer (for example, an ink jet printer), and the predetermined time is set to a predetermined type of data (for example, data related to an ink sequence). )
Is saved as a time for saving in the memory.

A power supply control device for a color liquid crystal display according to the present invention is a liquid crystal display in which the color liquid crystal display is driven by a first power supply and a second power supply, and the sequence for turning off the power supply is as follows.
Means for turning off the second power supply after turning off the first power supply, means for detecting a predetermined event, and means for turning off the first power supply when a predetermined event is detected Means for turning off the second power supply after the first power supply is turned off in relation to a specific internal process of the device equipped with the color liquid crystal display.

According to the power supply control device for a color liquid crystal display according to the present invention, when the power supply to the color liquid crystal display is turned off, it is needless to say that the power supply can be turned off in accordance with the power supply turn-off sequence specified for the color liquid crystal display. Without impairing the specific internal processing of the device equipped with the color liquid crystal display (for example, if the device is a printer, the time required for writing the status data to the memory at the time of turning off the power is maintained). The display can be turned off.

In a preferred embodiment, at least one of the means for turning off the first power supply and the means for turning off the second power supply turns off the power supply by a command or a signal.

In a preferred embodiment, the means for turning off the first power supply stops power supply to not only the first power supply but also a load other than the color liquid crystal display in the device.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking as an example the case where a device equipped with a color LCD is a printer.

FIG. 2 is a block diagram showing the configuration of the printer according to one embodiment of the present invention.

The printer 1 is based on a color LCD 9 for allowing the user to input various settings and inform the user of the status of the printer, a color LCD controller 7 for controlling the operation of the color LCD, and print image data. And a print engine 13 for performing printing. The printer 1 controls the color LCD controller 7 and the print engine 13, interprets print job data received from a host device (not shown), creates print image data in accordance with predetermined settings, and sends the print image data to the print engine 3. A printer controller 11 is provided. Also, the printer 1
Includes a printer reset control circuit 15 for controlling resetting of the entire system of the printer 1 and a power supply control circuit 5 for controlling electric power supplied from the commercial power supply 3 to each of the components 7 to 15. The color LCD 9 is connected to VDD (+
5 V) and VEE (−32 V). The color LCD controller 7 and the printer controller 11 are, for example, an ASIC (Application Specific
Integrated Circuit). Power supply control circuit 5
Reduces the AC voltage applied from the commercial power supply 3 to a predetermined voltage (for example, 42 V), rectifies and smoothes the reduced AC voltage to generate a DC voltage, and converts the power having the generated DC voltage into the above-described power. It supplies to each component 7-15.

The printer 1 is not provided with a power switch for switching the power on / off state of the printer 1 from the viewpoint of cost reduction. The power supply plug 100 is configured to be directly inserted into or removed from an outlet (not shown) of the power supply 3. When the power supply of the printer 1 is turned on or off by the power plug 100 being plugged into or unplugged from the outlet of the commercial power supply 3, the printer 1 turns on the power of the color LCD 9 according to a prescribed sequence. Turn on and off.

FIG. 3 shows various signals related to a process of turning on and off the power supply of the color LCD 9.

The signal 51 is a digital signal output from the print engine 13 to the printer controller 11 and indicates whether or not the print engine is being driven (hereinafter, this signal 51 is referred to as an engine state detection signal 51). Say). The engine state detection signal 51 indicates that the print engine 1
3 is at the H level when it is driven, and when the drive of the print engine 13 is stopped, the print engine 13
It falls from the H level to the L level. The engine state detection signal 51 is output from the commercial power supply 3 to the power plug 10.
Even when an interrupt described later occurs due to the fact that 0 is extracted and the applied voltage of the power supply control circuit 5 drops to a constant value, the voltage is also lowered from the H level to the L level.

The signal 19 (XPNLRST) is a digital signal output from the printer controller 11 to the color LCD controller 7 and controls resetting of a system other than the color LCD 9 and turning on the power supply of the color LCD 9. (In other words, color LC
D to control the on / off state of D) (hereinafter, this signal 19 is referred to as an LCD reset control signal 19). L
The CD reset control signal 19 is used when the system other than the color LCD 9 is reset.
1 causes the color LCD 9 to fall from the H level to the L level and release the reset state of the color LCD 9 (turn on the power supply of the color LCD 9).
It is raised from the level to the H level.

The signal 17 (XRST) is a digital signal output from the printer reset control circuit 15 to the color LCD controller 7 and controls resetting of the entire system of the printer 1.
This signal controls turning off the power supply of the CD 9 to completely turn off the power supply of the entire system or cancel the reset state of the entire system (hereinafter, this signal 17 is referred to as a system reset control signal 17). . The system reset control signal 17 is lowered from the H level to the L level by the printer reset control circuit 15 when the power of the color LCD 9 is turned off to completely turn off the power of the entire system, and the entire system is reset. When canceling the status,
It rises from L level to H level.

The signal 21 is a digital signal output from the printer controller 11 to the color LCD controller 7, and is a signal for switching whether the input is data or a command (hereinafter, this signal). 21 is referred to as a data / command switching signal 21). Color L to which data / command switching signal 21 is input
The CD controller 7 switches between accepting data and accepting a command depending on whether the signal 21 is at H level or L level.

The signal 23 is a signal output from the printer controller 11 to the color LCD controller 7 and includes data to be displayed on the color LCD 9 (hereinafter, this signal 23 is referred to as an LCD display data signal 2
3) The data included in the LCD display data signal 23 is displayed on the color LCD 9 by the color LCD controller 7.

The signal 25 is a serial signal output from the printer controller 11 to the color LCD controller 7, and is a signal for generating a clock in the color LCD controller 7 (hereinafter, this signal 25 is referred to as a shift clock signal 25). Say). When the signal 25 is input, the color LCD controller 7 generates clocks the number of times corresponding to the data included in the signal 25.

The signal 35 is the color LCD controller 7
Output to the power supply control circuit 5 from the VEE
(Hereinafter referred to as signal 3).
5 is referred to as VEE control signal 35). The power supply control circuit 5
The VEE control signal 35 input from the color LCD controller 7 controls the VEE voltage output to the color LCD 9. Specifically, when the VEE control signal 35 falls, the VEE is turned off and the VEE control signal 35 Is turned on, VEE is turned on.

The signal 37 is the color LCD controller 7
From the power supply control circuit 5 to the power supply control circuit 5,
(Hereinafter referred to as signal 3).
7 is referred to as a VDD control signal). The power supply control circuit 5 controls the voltage of the VDD output to the color LCD 9 by the VDD control signal 37 input from the color LCD controller 7, specifically, turns off the VDD when the VDD control signal 37 falls. And the VDD control signal 3
When 7 is activated, VDD is turned on.

The signal 39 is the color LCD controller 7
From the color LCD 9 to the controller (not shown) of the light source of the backlight of the color LCD 9.
D9 is a signal for controlling the ON / OFF state of the backlight power supply (hereinafter, this signal 39 is referred to as a BL control signal).

Although not shown in FIG. 2, a signal for detecting the presence of the color LCD 9 (hereinafter, this signal is referred to as an LCD detection signal) is output in the printer 1. The printer controller 11 samples the LCD detection signal. If the LCD detection signal falls (that is, if the L level), the printer controller 11 determines that the color LCD 9 is present, and if the LCD detection signal rises (that is, the H level). Assume that there is no color LCD 9.

FIG. 4 shows the configuration of the color LCD controller 7.

As shown in this figure, the color LCD controller 7 includes a VDD power control register 41,
Backlight power control register 43 and VEE
And a power supply control register 45. VDD
The logic level of the system reset control signal 17 is written in the power control register 41, and the logic level of the LCD reset control signal 19 is written in the backlight power control register 43 and the VEE power control register 45. The color LCD controller 7 controls each of the control signals 37, 39, 35 at a logical level corresponding to the logical level written in the registers 41, 43, 45.
Is output.

The printer 1 according to the present embodiment is configured as described above. Note that the color LCD 9 mounted on the printer 1 is stipulated to turn on VDD before turning on the power supply as a sequence when turning on the power supply, and to turn off VEE as the sequence when turning off the power supply. It is prescribed to turn off earlier.

Hereinafter, in this embodiment, the printer 1 uses the color L
The case where the power supply of the CD 9 is turned on and off will be described.

First, the case where the power supply of the color LCD 9 is turned on will be described.

FIG. 5 is a timing chart when the power supply of the color LCD 9 is turned on.

After the power supply plug 100 of the printer 1 is plugged into the commercial power supply 3 and the power supply by the power supply control circuit 5 is started, the printer controller 11 samples the state of the above-mentioned LCD detection signal, and if it has fallen ( That is, if it is at the L level), the presence of the color LCD 9 is detected (time t1). Then, the printer controller 11 raises the system reset control signal 17 to release the reset state of the entire system (time t2).

After a certain time, the printer controller 1
1 releases the reset state of the color LCD 9 and raises the LCD reset control signal (time t3),
At the same time, a predetermined number of clocks are input to the color LCD controller 7 as a command for turning on the power supply VDD of the color LCD 9 (hereinafter, a VDD power on command). The color LCD controller 7
When the clock of the number of times, that is, the VDD power-on command is received, the VDD control signal 37 is started to turn on VDD. When the VDD control signal 37 is raised, the power supply control circuit 5 turns on VDD (time t4).

Thereafter, the color LCD controller 7
Another predetermined number of clocks are input to the color LCD controller 7 as a command for turning on the power supply VEE of the color LCD 9 (hereinafter, a VEE power supply on command). When the color LCD controller 7 receives that number of clocks, that is, the VEE power-on command,
The VEE control signal 35 rises to turn on the VEE. When the VEE control signal 35 rises, the power supply control circuit 5 turns on the VEE (at time t).
5).

According to the above sequence, the printer 1
The power of the color LCD 9 is turned on.

Next, a case where the printer 1 turns off the power supply of the color LCD 9 will be described.

When the power plug of the printer 1 is pulled out from the commercial power supply 3 to turn off the power of the printer 1 (when resetting the entire system of the printer 1),
The status data indicating the state of the printer 1 (for example, when the printer 1 is an ink jet printer, the amount of ink remaining in the installed ink cartridge and the type of ink) are stored in the printer controller 11 over a predetermined period of time. Write to an EEPROM (not shown).
During this time, the power of the printer 1 is kept on.

When the power of the entire system is turned off when the power plug 100 is pulled out from the commercial power supply 3 and the power of the entire system is turned off, the printer 1 naturally turns off the power of the color LCD 9.
The power of the color LCD 9 is turned off in accordance with a prescribed sequence by using the time for writing to M. The details will be described below.

FIG. 6 is a timing chart when the power of the color LCD 9 is turned off.

When the power plug is pulled out from the outlet of the commercial power supply 3, the power supply control circuit 5
Starts to drop (time t1).

When the voltage applied to the power supply control circuit 5 drops to a certain value due to the removal of the power plug 100 from the commercial power supply 3, the print engine 13 detects this and generates an interrupt signal. The state detection signal 51 falls (time t2). At this time, the printer 1 starts writing status data in the EEPROM in the printer controller 11.

After the engine state detection signal 51 falls, the printer controller 11 falls the LCD reset control signal 19. LCD reset control signal 19
Is shut down, the color LCD controller 11
Causes the VEE control signal 35 to fall and the power supply control circuit 5 to turn off the VEE (time t3).

The system reset control circuit 15 operates at time t.
After the time 2, wait for the time required for writing the status data, for example, 260 msec.
The system reset control signal 17 falls. When the system reset control signal 17 falls, the color LC
D controller 7 lowers VDD control signal 37,
VDD is turned off by the power supply control circuit 5 (time t4).

The above is the description of the case where the power supply of the color LCD 9 is turned off. According to this, when turning off the power of the entire system, the printer 1 uses the two types of reset control signals 17 and 19 and keeps the write time of the status data while observing the specified sequence. Turn off the entire power supply. Specifically, when turning off the power of the entire system, the printer 1 lowers the system reset control signal 17 to first turn off the power supply VEE, which is defined to be turned off first, and to turn off the color LCD 9. Turn off other systems.
Then, the printer 1 waits until the writing of the status data is completed, and then the LCD reset control signal 19
Is turned off, and the power supply VDD, which is specified to be turned off next, is turned off so that the power of the entire system is completely turned off. That is, the printer 1
Indicates the status data write time length by the color LCD
9 is effectively used as a power supply turn-off time lag. For this reason, the time required until the power supply of the printer 1 is completely turned off does not become unnecessarily long.

Although the preferred embodiment of the present invention has been described above, this is an exemplification for describing the present invention, and is not intended to limit the scope of the present invention only to this embodiment. The present invention can be implemented in other various forms.

For example, as shown in FIG. 7, the printer 1 can turn off and turn off the power supply of the color LCD 9 by a command. Hereinafter, a specific description will be given.

The printer controller 11 sets the logic level of the data / command switching signal 21 to a logic level (for example, L level) for the color LCD controller 7 to accept a command.

In this case, when the power of the color LCD 9 is turned on, the timing of turning off the power of the color LCD 9 (for example, when a predetermined time elapses without changing the information displayed on the color LCD 9 or when the host device (For example, when the printer enters the power saving mode after a predetermined time elapses without print job data being sent from a printer (not shown).)
Next, the printer controller 11 inputs a command for turning off the power of the color LCD 9 (hereinafter, an LCD power off command) to the color LCD controller 7. When receiving the LCD power-off command, the color LCD controller 7 controls the VEE to turn off the VEE.
The EE control signal 35 falls. Thereby, the power supply control circuit 5 turns off the VEE (time t1).

Thereafter, at a timing when the power of the color LCD 9 is turned on (for example, when the information displayed on the color LCD 9 changes, or when the print job data is sent from the host device to release the power saving mode, etc.). ,
The printer controller 11 operates the power supply V of the color LCD 9.
A VEE power-on command for turning on the EE is input to the color LCD controller 7. Color LCD
When receiving the VEE power-on command, the controller 7 lowers the VEE control signal 35. Thereby, the power supply control circuit 5 turns off VEE (at time t).
2).

[Brief description of the drawings]

FIG. 1 shows an example of a sequence when a power supply of an LCD is turned off.

FIG. 2 is a block diagram showing a configuration of a printer according to one embodiment of the present invention.

FIG. 3 shows various signals related to processing for turning on and off the power supply of the color LCD 9;

FIG. 4 shows a configuration of a color LCD controller 7;

FIG. 5 is a timing chart when the power supply of the color LCD 9 is turned on.

FIG. 6 is a timing chart when the power supply of the color LCD 9 is turned off.

FIG. 7 is a timing chart when the power of the color LCD 9 is turned off and turned off by a command.

[Explanation of symbols]

 Reference Signs List 1 printer 3 commercial power supply 5 power supply control circuit 7 color LCD controller 9 color LCD 11 printer controller 13 print engine 15 printer reset control circuit 17 system reset control signal 19 LCD reset control signal 21 data / command switching signal 23 LCD display data signal 25 shift Clock signal 35 VEE control signal 37 VDD control signal 39 BL control signal 51 Engine state detection signal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/20 670 G06F 1/00 341Q F term (Reference) 2C061 AP10 HH01 HH03 HJ10 HK11 HK19 HN02 HN15 HN21 2H093 NC03 NC50 ND17 ND60 5B011 EB09 MB17 5C006 AA02 AA22 AF51 AF67 BF42 FA33 5C080 AA10 BB05 CC03 DD18 FF03 JJ02 JJ04 JJ05 KK02 KK07

Claims (9)

[Claims] 1. A power consuming unit that requires a predetermined end procedure when power is cut off, and a data process that uses the power consuming unit is executed. When the power is cut off, the process ends with another end procedure. A data processing unit that executes data processing and terminates the processing according to another termination procedure when the power is turned off; and a power supply unit that is connected to a main power supply and supplies a predetermined power to the power consumption unit and the data processing unit. A power supply control device for a microcomputer-based device that energizes and deactivates a power supply by directly energizing and deactivating the primary side of the power supply part, wherein the power generation part generates when the primary side of the power supply part is interrupted. A first reset function; and a second reset function that occurs after a predetermined time has elapsed since the first reset function occurred. A power control device for a microcomputer-based device, wherein when the reset function of (1) occurs, the predetermined end procedure is started, and when the second reset function is generated, the predetermined end procedure is completed. 2. The power supply control device for a microcomputer-based device according to claim 1, wherein the predetermined time is secured in advance as a time for the data processing unit to execute the other termination procedure. 3. The power supply unit according to claim 1, further comprising another power consuming unit different from the power consuming unit, wherein the power supply to the other power consuming unit is cut off when the first reset function occurs. The power supply control device for a microcomputer-based device according to claim 1. 4. The apparatus according to claim 1, wherein at least one or both of the first reset function and the second reset function are realized as a reset signal.
The power supply control device for a microcomputer-based device according to any one of the preceding claims. 5. The data processing unit according to claim 1, wherein at least one or both of the first reset function and the second reset function are realized as a command issued from the data processing unit. A power supply control device for a microcomputer-based device according to item 1. 6. The data processing section for controlling a printer, wherein the predetermined time is secured as a time for saving a predetermined type of data in a memory. 6. The power supply control device for a microcomputer-based device according to any one of items 5 to 5. 7. Power on / off of a color liquid crystal display
In the power supply control device for controlling an off state, the color liquid crystal display is a liquid crystal display driven by a first power supply and a second power supply, and the first liquid crystal display is a first liquid crystal display. Means for turning off the second power supply after turning off the power supply, means for detecting a predetermined event, and means for turning off the first power supply when the predetermined event is detected. Means for turning off the second power supply after the first power supply is turned off in relation to a specific internal process of a device equipped with the color liquid crystal display. 8. The color liquid crystal display according to claim 7, wherein at least one of the means for turning off the first power supply and the means for turning off the second power supply turns off the power supply by a command or a signal. Power control unit. 9. The color liquid crystal display according to claim 7, wherein the means for turning off the first power supply stops supplying power not only to the first power supply but also to a load other than the color liquid crystal display in the device. Power control unit.