JP3487595B2 - Information processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, along with the reduction in size and weight of personal computers, portable personal computers driven by batteries have appeared and are rapidly becoming popular. These are called laptop computers, and while they are small and lightweight, they have the same functions as stationary and laptop computers. Since it can be used with batteries, a new usage pattern has been created in which it can be used by bringing it to places such as conference rooms and lecture rooms where it is difficult to secure power.

However, in such a use form, the problem that the battery usable time is short is becoming a problem. When used for recording a conference in a conference room or recording a lecture at a university, it is desired that the battery can be continuously used for about 10 hours with one use. Looking at the margin, a minimum of 20 to 30 hours is required, and ideally 100 hours or more of battery life equivalent to a calculator is required.

On the other hand, the battery usage time of a notebook computer that is actually available is only 2 to 3 hours. Therefore,
During a long meeting, the battery runs out and the power is cut off and input work is interrupted during use. Also, since the battery usable time is short, it needs to be charged frequently, which is annoying.

Although the notebook personal computer is small and lightweight, the battery usage time is short, which makes it inconvenient to use the notebook personal computer.

Considering existing pocket-type portable information devices such as calculators and electronic notebooks, the processing speed of these is significantly slower than that of a personal computer, and the power consumption is accordingly small. Therefore, even if the current primary battery is used, it can be used for several years, and it is not necessary to care about the battery life. On the other hand, laptop computers consume as much power as they do as fast as stationary PCs. Therefore, the power consumption is 2 to 4 digits higher than that of the existing pocket type portable information device. Even with the use of high performance rechargeable batteries, current technology has the best battery life of 2-3 hours. As mentioned earlier, this battery life is not satisfying to the user. Various measures are conceivable as a power saving technique for compensating for this short battery life, and some of them are implemented.

The prior art will be described below.

First, what is generally called a "resume" function is installed in some notebook computers.
This system employs a system in which, when the computer is not used for a certain period of time, the information necessary for the last restart of the computer is saved in a non-volatile IC memory, and the power supplies of the CPU and display unit are automatically turned off. When the power switch is turned on when the user wants to use it again, the processing state and the display contents before the power-off is restored in a short time based on the saved information in the IC memory. This method has a practical effect of extending the usage time and is practical.

However, if no key input is performed for a certain period of time, for example, 5 minutes, all the power of the device is forcibly turned off.
Since the display disappears, the operator cannot confirm the displayed contents and the work is interrupted. When you want to check the displayed content or continue inputting again, you need to turn on the power switch. This is annoying to the user. This power saving method prolongs the effective battery life,
It had the drawback of being quite unusable.

[0010]

In the above-mentioned conventional configuration, as a means for reducing power consumption, almost all the power supplies including the main processing circuit section and the display circuit section are simply stopped. For this reason, as described above, the user will automatically turn off the power after a certain period of non-use,
In the case of intermittent processing work, it was necessary to turn on the power of the device frequently. In the case of a notebook computer, most of the users carry out intermittent processing, which makes this defect great.

The present invention is to solve the above-mentioned conventional problems, and when the fact that the unused state continues for a certain period of time is detected,
Alternatively, it is another object of the present invention to provide an information processing apparatus which, when the main processing is completed, stops the power supply of the main processing section and at the same time continues the display on the display section.

[0012]

In order to solve this problem, an information processing apparatus according to the present invention includes a backlight and a liquid crystal display.
Includes a display section and an information input section for inputting information from the outside
A liquid crystal display device, wherein the liquid crystal display section is
The transmission mode that displays by the transmitted light from the light and the outside
Display with reflection mode
If there is no input from the information input unit for a certain period of time, the backlight is turned off, and the liquid crystal display unit performs display in a reflection mode.

The information input section is used for external information from the user.
It is preferable to enter the information. Also, the information input unit
Can enter external information from the communication interface.
And are preferred. Further, the information processing device is preferably a battery-powered portable information processing device. Also,
It is preferable that the information processing device turns off the backlight when the input of the information input unit is not performed for a certain period of time and the processing frequency of the CPU is low. Also, the above
The information processing device can be driven by two power sources, an external power source and a battery. When the external power source is used, the backlight is turned on to display in a transparent mode, and when the battery is used, the backlight is turned on. It is preferable to turn off and display in the reflection mode. Further, the liquid crystal display unit, a reflective layer and a liquid crystal layer is provided on the display side with respect to the backlight,
The reflection layer is configured to reflect incident light that has entered from the display side through the liquid crystal layer and to exit to the display side through the liquid crystal layer, and the reflection layer has a plurality of openings. It is preferable that the light from the backlight is transmitted through the opening, and the transmitted light thus transmitted is emitted from the display side through the liquid crystal layer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.
A description will be given with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of an information processing apparatus in a first embodiment of the present invention. The information processing apparatus is composed of four blocks of an information input unit 3, a first processing block 1 and a second processing block 99.

First, in the information processing apparatus, when there is a key input from a user in the information input unit 3 such as a keyboard or an external input by an information input means such as a communication interface,
Communicate information to processing block 1. The first processing unit 4 detects which key of the key input is pressed or what information is input from the outside, and determines the next processing based on the information in the first memory 5.

First, as shown in FIG. 2A, when there is no input information in the information input section 3 for a certain period of time and when the operation of the second processing section 7 is completed, the interruption control section 6 causes the second processing section 7 to operate. The clock signal is stopped and / or the power saving process is forcibly performed on the display circuit unit 8.

The power saving method will be described in detail with reference to FIG.

As shown in FIG. 2a, when the information input section 3 receives the nth key input at t = t1, this information is sent from the information input section 3 to the first processing section 4.

Then, the content of the key input is judged by the first processing section 4, and only when the processing of the second processing section 7 is necessary, the second processing section 7 is sent to the second processing section 7 through the interruption control section 6 and the start command line 80. A start command is sent to forcefully activate the second processing unit 7 to activate the second processing unit 7.
Send information to. As shown at t = t3 in FIG. 2C, the second processing unit 7 performs processing according to the input after being activated, and after the completion of the processing of the second processing unit 7, sends an end signal to the first processing unit 4. The sending first processing unit 4 or the interruption control unit 6 uses the start command line 80
An end command is sent to the second processing unit 137 via. Then, the second processing unit 7 sends information about the final processing content, for example, RA.
The contents of the M memory and the contents of the register are temporarily saved in the second memory 9. After that, as shown at t = t5 in FIG. 2c, the processing of the second processing unit 7 is stopped or the function is lowered to drastically reduce the power consumption, and the power saving mode is entered. Even after t = t5 when the second processing unit 7 is stopped, the second memory 9 is backed up by a battery or a non-volatile memory is used, so that the memory contents are saved. When the display change is necessary, the second processing unit 7 sends the display change information to the first processing unit 4. The first processing unit 4 sends a display activation command to the display circuit 8 via the display activation command line 81 to activate the display circuit. As shown in FIG. 2d, the information processed at t = t4 is sent to the display circuit unit 8, and the display circuit 8 calls the image of the previous display contents from the video memory 82 or the second memory 9, 2) A new image is created based on the display change and information sent from the processing unit 7.
Then, the processing information is displayed on the display unit 2. After that, the display circuit 8 sends its command or an end signal to the first processing unit 4 via the interruption control unit 6 at t = t6, and stops the operation of the clock or the like of the display circuit 8 based on the instruction of the first processing unit 4. Alternatively, the power consumption of the display circuit 8 thereafter after the speed is reduced and the display power saving mode is entered is significantly reduced as shown after t = t6 in d of FIG.

After t = t6, the display circuit section 8 is in a stopped state or a state close to a stopped state, but since the display section 2 is composed of an element having a memory effect such as a ferroelectric liquid crystal, the display content is retained. . Here, the contents of the display unit 2 will be described. In the case of the simple matrix liquid crystal, the display unit 2 has matrix electrodes as shown in FIG. The horizontal drive unit 11 and the vertical drive unit 12 are composed of horizontal drive lines 13 and vertical drive lines 14 in two horizontal and vertical directions. FIG. 4 shows one state of the pixel according to the voltage application.

In each pixel, a signal is applied to the ferroelectric liquid crystal 17 by the electrodes formed by the horizontal drive line 13 and the vertical drive line 14 provided on the glasses 15 and 16.

FIG. 4A shows a state when no light is transmitted. By applying a signal, the direction of the ferroelectric liquid crystal 17 is changed, the polarization angle of the transmitted light is changed, and by configuring a polarizing plate, light is transmitted in this state.

Next, when a reverse voltage is applied, the direction of the ferroelectric liquid crystal 17 is changed and the polarization angle of the transmitted light is rotated by 90 degrees,
The polarizing plate prevents light from passing through as shown in FIG. One of the characteristics of ferroelectric liquid crystal is the memory effect.
As shown in FIG. 4C, the same state as that of FIG. 4B is maintained even when the power supply is stopped. Therefore, the display is continued from t = t6 to t = t14 described below without operating the display circuit 8 at all. Thus, after t = t6, the power saving mode is set, and the information input unit 3 and the first processing unit 4 are merely operating.

The first processing section 4 only performs processing such as conversion of key input into character codes. Since this key input is performed manually by a human, it can be input only tens of times per second at most. The human input speed is several orders of magnitude slower than the processing speed of the microcomputer. Therefore, the processing speed of the first processing unit 4 may be as slow as a calculator. Therefore, the power consumption is several orders of magnitude lower than that of the CPU of a stationary personal computer. As shown in FIG. 2B, the first processing unit 4 includes the power switch 20 of the information processing apparatus 1.
Although it operates while is on, it consumes less power, so the overall power consumption can be reduced.

Next, when there is an N + 1th key input at t = t11, at t = t12, the first processing unit 4 judges the content of the key input, and if necessary, via the interruption control unit 6, or An activation command is directly sent to the second processing unit 7 to activate it. The second processing unit 7 restarts the processing by the clock based on the start instruction, and the information stored in the second memory unit 9, that is, the information when the previous stop was performed at t = t5, for example, the memory contents, the register information, the display contents, etc. The information is read and the CPU environment at t = t5 is completely restored. Thereafter, at t = t13, the information from the first processing unit 4 is sent to the second processing unit 7, and the processing is restarted. Since the second processing unit 7 has a high processing speed so that high-speed calculation can be performed, the power consumption is close to that of a general personal computer. If operated continuously, the battery life is short, just like existing laptops. However, in the present invention, since the power saving mode is intermittently entered, the power consumption is reduced accordingly.

Explaining this power saving mode, for example, W
In the case of P software, the time required for one processing is usually 1 m
s or less. On the other hand, human key input is tens of ms at the fastest. Therefore, as shown in FIG. 2c, the peak power consumption of the second processing unit 7 from t13 to t15 is large,
The average power consumption is several tenths to several hundredths of this peak value. That is, a large power saving can be achieved by the power saving mode.

At t = t14, the second processing unit 7 causes the display unit 2 to operate.
Sends only the information that changes the displayed content to.

Before t = t14, the display unit 2 continuously displays the display contents changed at t = t6, even if the display circuit 8 is not operating, due to the memory effect of the ferroelectric liquid crystal 17. There is. Partial rewriting is performed at t = t14 only for the portion whose display content is changed based on the key input of t = t11. This partial rewriting is a specific horizontal drive line 1
3 and a specific vertical drive line 14 are applied with a voltage to change the display content from one line to several lines. In this case, the processing time is shorter than that of the entire rewriting, and the power consumption is correspondingly reduced.

The second processing unit 7 at t = t15 in FIG.
Stops operating and enters power saving mode again. T in FIG. 2c
The second processing unit 7 saves the final processing information in the second memory 9 when the processing of the second processing unit 7 is completed before = t15 or when the end command is received from the first processing unit 4. .

Next, at t = t14, the second processing unit 7 stops or slows down its operation, and enters the input saving mode. t = t21,
When input information arrives at short intervals such as t31, t41, and t51, for example, when a plurality of keys are input or input from a communication port, t = t23, t33, t43 and power saving as shown in FIG. Enter the mode. When the first process 4 determines that the interval of the input information is shorter than the fixed interval, the first process 4 issues a power saving mode stop command, and the second process is performed after t = t43 in c of FIG. The processing unit 7 is not forcibly terminated and the power saving mode is not entered. Then, when the interval of the input information becomes long, the power saving mode is started as before.

When the first processing unit 4 detects that there is no key input for a certain period of time, the main operation including the first processing unit 4 is stopped, the power is turned off, and the power supply stop mode is entered. However, the memory contents are backed up by batteries.
The power is almost completely turned off.

However, before the power is turned off, the first processing unit 4 sends a power stop display command to the display circuit 8 directly or via the second processing unit 7 to display the seventh display 21 as shown in FIG. 5 (b). Display and power off After displaying, enter power off mode. Since the display unit 2 has a memory effect, this display is displayed even after the power supply is stopped, so that the user can distinguish between the power saving mode and the power supply stop mode.

In the power saving mode, the operation is restarted by key input, and the user does not need to be aware that the operation is interrupted.

However, in the case of the power stop mode, since the display of the power stop is displayed, the user turns on the power switch 20 so that the second processing unit 7 causes the second memory 9 to perform the previous process. You can restore the state and start the next work that is continuous with the previous one. This part is the existing "Resu
Same as "me" mode.

The above operation will be described below with reference to the flow chart of FIG. In step 101, the power source S
When WON is performed, the first processing unit 4 starts operating in step 102. Input information such as a key input from the information input unit 3 is sent to the first processing unit 4 in step 103, and it is determined in step 104 whether or not there is an input interruption state for a certain period of time. If the input interruption time: t is large, the process goes to step 105. If the second processing unit 7 is in operation, the process returns to step 103.
Then, the operation is stopped in step 107 and stopped until the power supply SW in step 101 is pressed.

Returning to step 104, if the input interruption time t is several minutes, the process proceeds to step 108.
If the processing frequency of the processing unit 7 is low, the power source of the backlight is turned off in step 108 to enter the backlight power saving mode.

Here, returning to step 104, if the input interruption time t is small, the process of the first processing unit in step 110 is checked in step 110a whether the display is long-lasting. The display of the display unit 2 is refreshed in step 110b for preventing the image sticking, and the processing frequency of the second processing unit is determined in step 112a. If it is small, go to step 111.
When it is determined in step 111 that the process of the second processing unit 7 is not necessary, the process returns to step 103.

When it is determined in step 111 that the process of the second processing section 7 is necessary, the process proceeds to step 112. a
If the second processing unit 7 is not operating in step 112, the process proceeds to step 113a, and an instruction to activate the second processing unit 7 is issued to the second processing unit 7. In response to this, step 11
In 3, the second processing unit 7 is activated by the first processing unit 4 and the interruption control unit 6, and the processing of the second processing unit is started in step 114. When it is determined in step 115 that the display has been changed, the second processing unit 7 performs step 116.
At a, display polarization information is given to the interruption controller 6 and the first processor 4. Then, in step 116b, the interruption control unit 6 sends a display unit activation command to the display block 99. Step 116c
In step 117, the display circuit 8 is activated to change the display including partial rewriting of the display part 2. In step 118, after confirming the display change, the display completion information is sent to the first processing part 4 in step 117a. The display completion command is received at 117b, and the operation of the display unit is stopped at step 119.

Here, returning to step 115, if there is no display change, the process returns. After confirming the processing completion of the second processing unit 7 in Step 120, the completion information of the second processing unit is generated in Step 120a, the processing unit end command is received, and the function of the second processing unit 7 is stopped in Step 121. After doing step 1
Return to the state of 03.

FIG. 7 and FIG. 8 are block diagrams when the first embodiment is specifically configured as a notebook computer.

Referring to FIG. 8, the information input block 97 comprises a keyboard 201, a communication port 51 of RS232C and a flexible disk controller 202. There is another hard disk 203. The first processing block 4 is mainly configured in the first processing block. Second
In the processing block 98, a CPU of a system that enters a power saving mode by stopping the clock and returns by supplying the clock
There is a second processing unit 7 that adopts the above, and the bus line 210 is connected. The bus line 210 has a boot ROM
204, a second memory 9 composed of a DRAM, and a backup RAM 205 composed of an SRAM for storing return information from the resumed state of each part at the time of resume. The bus line 210 includes the first processing unit 4 and
A display block 99 is connected. Display block 99
In the figure, a graphic controller 206 and a liquid crystal controller driver 207 are included as a display circuit. There is also a video RAM 209 and a liquid crystal 208.
It is possible to save power by setting some of the above components to the operating state and the rest to the stopped state. Table 1 shows this power saving method.

[0043]

[Table 1]

During normal input such as WP, intermittent keyboard input is performed. Therefore, except for the communication input / output unit,
Turn on. Then, the clock is given to the first processing block 1 and the clock is not given to the second processing block 98 and the display block 99. Therefore, power consumption occurs only in the first processing block. If necessary, a clock is supplied to the second processing block 98 and the display block 99 to intermittently activate for a short time. Next, in the case of frequent processing, the second processing block 98 is always kept in the clock operating state to increase the processing speed.

When there is no keyboard input for a certain period of time, the second
The power of the processing block 98 is stopped, the contents of the memory are backed up, and the process is restored when the next keyboard input comes.

Although FIG. 8 is almost the same as FIG. 7, the first processing unit 4 having a low clock frequency is used as an overall “monitor”, and the actual processing is performed by the second processing unit 7 having a high clock frequency.
It shows the case of doing. The first processing unit 4 is the keyboard 2
This is a method of performing event processing in which the second processing unit 7 is activated and processed each time in response to a keyboard input of 01. After the processing is completed, the second processing unit is stopped to save power. Stop until next keyboard input. Display block 9
9 is started based on the display signal from the second processing unit 7, and automatically stops after the display is completed. The method of FIG. 8 has an effect of operating on an OS close to the conventional OS, and has high compatibility with conventional software. Conventional MS-DOS is designed to work with one CPU. In the method of FIG. 7, the CPU
Since it can be regarded as two, compatibility problems may occur when running conventional application software. Further, even if there is no compatibility problem, the power saving effect is reduced in the conventional OS.
Therefore, by installing the conventional OS, the dedicated CPU for 2 CPUs of the present invention, and the dedicated software, the software for the dedicated OS of the present invention can be operated when used in WP software.
Measures power saving by several hundredths. And general-purpose software,
Use OS for conventional OS. In this case, the power saving effect is reduced. In fact, about 80% of notebook computers are used for WP, so this configuration can achieve a great power saving effect.

FIG. 9 is another concrete block diagram of the first embodiment, and FIG. 10 is a flow chart. This is MS-
The method disclosed in the case of operating with a conventional OS such as DOS is disclosed. The second processing unit 7 uses a CPU that retains information such as registers and internal RAM even when the clock and power are stopped. When there is a key input in step 251, the first processing unit 4 sends the keyboard code signal from the keyboard 201 to the activation unit 221 in the always operating state in step 252. Step 253 activation unit 22
No. 1 sends a clock to the main processing unit 222 which is in a dormant state to activate it. Register 224 and internal RAM 2
Since 23 is backed up, it is instantly activated by the clock supply. In step 254, the main processing unit 222
Is stopped in the state where the program is on standby for input, the program starts from this state. Then, in step 255, keyboard input is received and program processing such as WP is performed. Depending on the processing in step 256,
If necessary, a display command is output to rewrite the display in step 257. In step 256, the graphic controller 206 is activated, and in step 259, the video RAM 20
9 is rewritten, the liquid crystal controller driver 207 is activated in step 260, the liquid crystal 208 of the ferroelectric liquid crystal is partially rewritten in step 261, and then step 2
After backing up the VRAM 209 at 62, the display block 99 is stopped and the power saving mode is entered at step 263. After the processing of the second processing unit 7 is completed in step 270,
In step 271, the running program is stopped at the "keyboard input standby state", and in step 272, the contents necessary for the restoration of the register 223 and the internal RAM 234 and the second memory 9 are backed up.
Stop the PU clock. In step 273, the second processing unit 7 is stopped and the power saving mode is entered. However, the starting unit 2
Since 21 is in operation, in step 251, an input standby state is set until a new keyboard input or an input from the communication port 5 is made. Therefore, in the second processing block 98, only the activation unit 221 is operating. In the system of FIG. 9, this CPU can back up and hold the contents of registers and the like even if the clock is stopped. With the clock restart,
A CPU that instantly returns is used. Only one CPU operates mainly. Therefore, the conventional OS can be used. Since software such as conventional WP can be used with a slight change, there is a great effect that conventional software assets can be used. Therefore, at this point, it is a very realistic method. By directly rewriting the display by the first processing unit 4 as in the second embodiment described later, it is possible to further reduce the power consumption.

When there is no keyboard input for a long time, the resume mode is entered and most of the power supplies are stopped. In particular, a ferroelectric liquid crystal has a memory effect, but when the same display content is continuously displayed, a permanent memory effect called a standing metastability phenomenon appears. In order to avoid this, in the power saving mode or the power stop mode, the timer 22
However, if it judges that the display continued for a certain period of time,
A display change command is sent to the first processing unit 4 and the power switch 20, and the display circuit 8 rewrites all or part of the display content of the display unit 2 to prevent a permanent memory phenomenon.

In the unlikely event that a permanent memory phenomenon occurs and a part of the display unit 2 cannot be changed in display, the temperature of the display unit 2 is raised by the display reset SW 23 via the heater 24 to arrange the liquid crystal. The display contents of the display unit 2 can be changed again.

In the power saving mode, the power can be reduced by stopping the clock of the second processing unit 7, but to further reduce the power, the interruption control unit 6 supplies power to the second processing unit 7 or the display circuit 8. By stopping the power saving, more complete power saving can be achieved.

In the power stop mode, only the power backup of the second memory 9 is consumed.

When the battery is used as shown in FIG. 1, the backlight 25 is turned off, and the reflection element 27 is operated via the reflection circuit 26 to use in the reflection mode.

As shown in FIGS. 12A and 12B, the reflection element 27
For the transmission shown in FIG. 12A, the transmission mode and the scattering mode of the film-shaped ferroelectric liquid crystal element are used.
The reflection shown in (b) can be used to switch between reflection and transmission. Incident light 32 is diffusely reflected by the reflection unit 27 and reflected light 33
Becomes In this case, the polarizing film can reduce the number of parts by using the display unit 2 and the polarizing plate of the reflective element 27 as well. Further, by using a film-shaped electrochromic display element, two modes of a transmissive state and a white diffuse reflection state like white paper can be realized.

The reflecting element 27 may be of a fixed type as shown in FIGS. 13 (a) and 13 (b). The reflection element 27 is composed of a light transmission part including a low refractive index light transmission part 28 and a high refractive index light transmission part 29, and a reflection part 31 partially having an opening 30.

As shown in FIG. 13 (a), the light from the backlight unit 25 enters the light-refractive-index light transmitting unit 29,
The light is totally reflected at the interface with the low-refractive-index light transmitting section 28, enters the polarizing plate 35 through the opening 30 as shown in the figure, enters the liquid crystal section 17 after being polarized, and is emitted to the outside to provide a bright display. Done.

Next, when the battery is used in the reflection mode, as shown in FIG. 13 (b), the light 32 from the outside is transmitted through the liquid crystal portion 17 and reflected by the reflection portion 31 made of aluminum vapor deposition or the like. The reflected light 33 passes through the liquid crystal 17 and is displayed outside.

Since the reflecting section 27 does not require an external drive circuit, it has the effect of simplifying the overall structure. The method of creating the light refractive index and the low refractive index can be prepared easily by a method of attacking a molten salt, which is generally used for a gradient index lens.

The transmissive / reflective liquid crystal display has a problem that the display quality is inferior to that of the transmissive or reflective liquid crystal display. The effect of being able to display the same as with the dedicated type is created. For this reason, it is suitable for dual battery / AC drive applications.

When an external power source is used, the backlight 25 is turned on by a command from the first processing section 4 and the first
A transmission command is sent from the processing unit 4 to the reflection circuit 26, and the reflection element 27 enters the transmission state, so that the display becomes very bright due to the transmitted light as shown in FIG.

Next, when the battery is used, the first processing unit 4 sends a reflection command to the reflection display circuit 26, and the reflection element 2
7 is in a reflective state including diffused reflection, and as shown in FIG. 12B, display is performed by reflected light by external light. In this case, the power consumption is reduced by the amount of the backlight 25.

Further, as shown in FIGS. 14A and 14B, by using a reflection / transmission plate 34 in which a tapered hole is formed in a metal plate such as aluminum, the reflection / transmission plate 34 shown in FIG.
The same effect as (b) can be obtained.

With the above-described structure, the CPU operates intermittently in response to intermittent key input, and the average power consumption is greatly reduced.

Further, in this case, since the display is continued, even if the operation of the processing section is stopped, the user does not feel any strangeness. Therefore, there is an effect that a large amount of power can be saved without impairing operability.

Further, specifically, the key input cycle is several tens of meters.
On the other hand, in the case of WP software or the like, the average CPU processing time is several tens to several hundreds of μs, so that it is only necessary to work an operating time of 1/100 to 1/1000 of several tens of ms. Therefore, the power consumption is also reduced in conjunction with the intermittent operation. However, the intermittent operation of the CPU alone consumes 0.5 to 1 W, which is about 10 to 20% of the power of the entire display. Therefore, even if the power consumption of the CPU is reduced to 1/1000, the display operates. If so, 1/10 to 1/5 of that before measures
Power consumption will remain. In the present invention, since a display element having a memory effect, such as a ferroelectric liquid crystal, is used for the display section, the power consumption required for display can be intermittently operated like the CPU.

Therefore, in the case of key input such as WP, the total power consumption can be reduced to 1/100 to 1/1000.

(Second Embodiment) FIG. 15 shows a block diagram of an embodiment. In the second embodiment, the function of the first processing unit 4 is strengthened and the frequency of operation of the second processing unit 7 which consumes a large amount of power is further reduced, so that the power consumption can be further reduced.

The difference in the configuration of the first embodiment from FIG. 1 is that the first
There is a signal line 97 for transmitting a display instruction signal from the processing block 1 to the display block 99. The first processing unit 4 in the first processing block 1 directly issues an instruction change signal to the display circuit 8 in the display block 99 to change the display content of the display unit 2. In the first embodiment, the second processing unit 7 uses the display circuit 8
The point that the display change signal is given to the.

FIG. 16 is a block diagram related to the first processing unit 4, which is described in more detail.
The memory unit 5 has a first font ROM unit 40 for storing a dot pattern of fonts such as alphabets and kana by a ROM or the like, an image memory unit 41, and a general memory unit 42.

Further, as shown in FIG. 11, the second font ROM section 43 in the second memory section 9 can be used as the font memory.

Therefore, only the first processing unit 4 can perform the following series of simple display changing processes. A character code is generated based on key input, and a font pattern corresponding to the character code is generated in the first font ROM unit 40 or the second font R.
A display can be displayed on the display unit 2 from the OM unit 43 via the reading display circuit 8. The second memory 9 has a second
There is a general memory 44.

That is, when a data character string that does not involve a large process is input, the low power consumption first processing unit 4 mainly performs a display changing process. When large processing is required, the second processing unit 7 with large power consumption performs processing. As a result, the operation frequency of the second processing unit 7 is reduced, and the power consumption is further saved. In this case, as shown in FIG. 16, the memory of the first memory unit 5 can be reduced by calling the font pattern of the second font ROM 43 in the second memory unit 9.

The second embodiment will be described with reference to the flow charts of FIGS. 18 and 19, and the flowchart of FIG. 18 is basically the same as the flowchart of FIG. 6 of the first embodiment.

The difference is that the first processing section 4 directly activates the display circuit 8. Therefore, step 130 and the display flowchart 131 are added. In step 130, it is determined that the first display unit 4 is a simple display change that can be processed.
When the processing unit 4 makes the determination, the process proceeds to the display flowchart 131. To briefly explain this, first, step 13
The display block 99 is activated in 2 and the display content is changed in step 133. After confirming the display change in step 134, the power of the display block is turned off in step 135 to return to the standby state for information input in step 103. FIG. 19 illustrates the change of the display contents in step 133 in more detail. First processing block 1 in step 132
After activating the display block 99 according to the activation signal, the cursor is partially rewritten in step 141 if the cursor is moved only in step 140. If not, it is confirmed in step 142 whether or not the display is already present in the input planned area of the display unit 2. This allows the contents of the image memory unit 41 to be confirmed by the first processing unit 4. In the case of NO, the partial rewriting process of step 143 is performed as it is. If yes, step 14
Go to 4. In step 144, the display content existing in the input planned area of the display unit 99 is confirmed in the image memory 41, and it is determined whether the previous display content is necessary for the current display change. In the case of NO, it is only necessary to overwrite by partial rewriting in step 143. If yes, step 1
At 45, an image corresponding to the planned input area is called from the image memory 41 or the second font ROM 9,
In the future, we will synthesize a new image to be displayed. In step 146, it is determined whether or not the black and white opposite mode is set, and YES.
Then, in step 147, the corresponding portion of the image is displayed in reverse. If NO, the display is partially rewritten in step 148 and the display change is confirmed in step 134, and the display block 99 is stopped in step 135.

More specifically, FIG. 20 shows the processing status of each part in response to a key input. When there is a key input "I" shown in e of FIG. 20 at t = t1,
The first processing unit 4 converts the character code to "I", reads the font pattern corresponding to this character code from the first font ROM 40 shown in FIG. 16, drives the display circuit 8, and displays it on the display unit 2 as shown in FIG. 20e. The display "I" is generated. In this case, in the case of a memory effect type display such as a ferroelectric liquid crystal, partial rewriting is possible. There are two methods for rewriting the part. One is to rewrite one dot and rewrite all dots for one horizontal or vertical line. There is line rewriting. Of course, dot rewriting consumes less power, but requires a high voltage and is costly. For line rewriting, even if one dot is rewritten, it is necessary to rewrite one line, but a low voltage is sufficient. In the embodiment, both display methods will be described.

If the withstand voltage of the horizontal drive section 11 and the vertical drive section 12 shown in FIG. 3 is high, the partial rewriting can be performed on a point-by-point basis only for the "I" column. Therefore, in this case, the first
The processing unit 4 may generate information for one font corresponding to "I". However, the cost of an IC having a high breakdown voltage is high.
In order to reduce the cost, it is desirable that this breakdown voltage is low. Therefore, in the current semiconductor process, it is necessary to support partial rewriting on a row-by-row basis in order to reduce the required breakdown voltage.

In this case, the first processing section 4 uses the first memory 5
It must have at least one line of image memory inside.

In the case of Japanese, the memory is 640 × 24 dots. In this case, in order to rewrite "I", it is necessary to rewrite one line, that is, 640 dots, for 24 lines.

The previous image is read from the image memory 41 of the first processing section 5, the pattern of "I" is read from the first font ROM 40, and is combined to form an image for one line. Based on this information, one line of the display unit 2 is rewritten via the display circuit 8. At the same time, the new line image is stored in the image memory 41. This completes the display change of "I".

In this case, when the second font ROM 43 is used as shown in FIG. 16, only one line of code information is required, so the first font ROM 40 and the image memory 41 are unnecessary. In this case, the data for one line is about
40 characters 2-byte characters, 40 x 2 = per line
80B is enough. In this case, the code information for all screens
It can also be provided inside the memory 5.

The display of "I" is completed by the above two methods. In this case, the processing of the second processing unit 7 is not performed at all as shown in FIG.

Similarly, at t2, "space" is t3, "L" is t4, "i" is t5, "v" is t6, and "e" is a display corresponding to the key input. Done in.
The processing speed of the first processing unit 4 is remarkably slower than that of the second processing unit 7, but the processing speed is sufficient to perform the display processing for one line. As a result, low power consumption can be achieved.

FIG. 20t7 shows a state in which a key input for instructing a large amount of processing, for example, spell check at the time of WP input, Japanese-to-English translation processing, and Japanese kana-kanji conversion processing spreadsheet operation instruction is entered. Shows.

In this case, the first processing unit 4 determines that the processing of the second processing unit 7 is necessary, and activates the second processing unit 7 at t71. This activation state is the same as that described in the first embodiment. The second processing unit 7 is t71 as shown in FIG.
The first processing unit 4
The information displayed on the display unit 2 is changed via the display circuit 8 at t72 as shown in FIG.

This process can be easily explained by using an input example of translation processing from Japanese to English. In FIG. 20f, t2
Then, K is key-inputted and K is displayed as it is in FIG. 20h. When a is input at t1, “ka” is displayed as shown in FIG. 20h.

Up to this point, the second processing section 7 does not operate as shown in FIG. When the translation conversion key is pressed at t7, the processing of the second processing unit 7 starts at t71, and the translation processing translates the Japanese word "kareha" into the English word "He is". The result of this processing is sent to the display circuit 8 and dot rewriting is performed.

"He is" is displayed as shown in FIG. As shown in g of FIG. 20, the power consumption at the time of dot rewriting is smaller than the power consumption at the time of line rewriting shown in d of FIG.

Next, in order to reduce the power consumption when moving the cursor with reference to FIG. 21, if the black and white inversion mode is used as shown in FIGS. 21A and 21B, the power consumption is large in the case of line rewriting. . Therefore, by displaying the horizontal bar cursor by using the line between the lines as shown in FIGS. 21C and 21D, it is not necessary to rewrite the display of one line, and power can be saved. Further, since the speed is increased, the response becomes faster even if the processing is performed by the low-speed first processing unit 4. This is also effective in the dot rewrite mode.

As shown in FIG. 22A, the horizontal bar cursor is used only for moving the cursor. In this case, it is more effective to intermittently perform the black and white reverse display by the first processing unit 4 in order to make it conspicuous. Only when there is a key input as shown in (b), one character is highlighted.
This switching reduces power consumption at least when the cursor is moved.

22A to 22H correspond to t1 to t7 in FIG. 20, and (i) shows the display at the time of reconversion.

FIG. 23 shows states (a) to (g) at the time of inserting and inputting in a sentence at the time of dot rewriting.
When M is used in the configuration of FIG. 16, not all Kanji codes are stored in the first font ROM 40, so it is necessary to store one line of image information in the image memory 41. When moving backward as shown in FIGS. 23 (c) to 23 (d), the image "n" is restored from the image memory 41.
The display of (d) is possible without using M43.

24A to 24G show a state in which the character string "He is man" is copied. (a) to (f) can be processed only by the first processing unit 4. Since (g) requires insertion processing, it can be processed almost by the capability of the first processing unit 4. The second processing unit 7 operates.

In the case of the second embodiment, most of the portion processed by the second processing unit 7 in the first embodiment is the first with low power consumption.
Since the processing unit 4 performs the processing, there is an effect that the average power consumption is further reduced as compared with the first embodiment.

However, it is possible to use the WP and spreadsheet software to
The optimum values of the sharing ratios of the processing unit and the second processing unit are different. Therefore, the first processing unit 4 can change the shared content by software to optimize the balance between power consumption and processing speed. Further, as shown in FIG. 25, the video memory 82 is added to the display block 99, and the first processing unit 4 and the connection line 96 are connected, so that the previous display image is the video memory 82.
16A, the image memory 41 of FIG. 16A can be omitted.

(Third Embodiment) FIG. 26 is a block diagram of the third embodiment. The parts different from Example 1 and Example 2 are
As is apparent from FIG. 1, in the first embodiment, both the start instruction and the end instruction are sent from the first processing block 1 to the second processing block 98 via the start instruction line 80.
Further, both the start command and the end command are sent from the first processing block 1 to the display block section 99 via the display start command line 81.

However, in the third embodiment, as is apparent from FIG. 26, first, the display activation command line 8 to the display block 99 is displayed.
There is no 1. Next, in the start command line 80, only the start command is sent from the first processing block 1 to the second processing block 98, and the end command is not sent.

When the second processing section 7 finishes the processing, it performs the stop processing by itself and enters the power saving mode. The display block 99 is activated by issuing a display activation command to the display block 99 via the data line 84 when the second processing unit 7 determines that the display change is necessary. When the display change of the display unit 2 is completed, the display unit lock 99 stops operating,
Display Enter power saving mode. This will be described with reference to the flowchart of FIG. This flowchart is divided into three parts, a first processing step group 151, a second processing step group 152, and a display step group 153. First, the difference will be described from the time of starting and stopping the second processing block 98.

Flowchart of Embodiment 1 The point different from FIG. 6 is that the second processing block 98, that is, the second processing block 98
There is no control flow from the processing step group 152 to the first processing block 1, that is, the first processing step group 151. That is, the first processing unit 4 sends an instruction to activate the second processing unit 7 to the second processing unit 7 in step 112, and the second processing unit 7 is activated. Only this point is common to the first embodiment. Regarding the stop, the function of the second processing unit is automatically stopped at step 121 without receiving the command from the first processing unit 4 which is different from the first embodiment. Then, in step 103, the information input standby state is entered.

Next, the difference from the first embodiment regarding the activation and deactivation of the display block 99 will be described.

In the first embodiment, the second processing section 7 sends the display completion information to the first processing block 99 as a display start command. However, in the third embodiment, the second processing block 98 sends an activation command to the display block 99 in step 115a of FIG. 27, the display block 99 is activated in the display step 116, and the display content is changed in step 117. After confirming the display change in step 118, the display block 99 is stopped by itself in step 119.

As described above, the third embodiment has the same function as that of the first embodiment, but the second processing block 98 and the display block 99 are automatically stopped.

Further, the start instruction of the display block 99 is the second instruction.
Processing block 98 is issued. Therefore, the load of the first processing block 1 is reduced, and not only the overall speed is increased, but also the configuration is simplified.

(Embodiment 4) FIG. 28 shows a block diagram of a fourth embodiment. The fourth embodiment discloses a power saving method according to the present invention when it has an input / output for communication with the outside. The information processing apparatus has an input / output unit 50 for inputting / outputting with the outside in the information input block 97, in which the communication port 5 is provided.
1 and an external interface unit 52. When there is an input / output, it operates as shown in the timing chart of FIG. This operates similar to the timing diagram for the key input shown in FIG. When the input from the communication port shown in a of FIG. 29 is t1 to t74, the communication port unit 51 in the input / output unit 50 sends a signal to the first processing block 1. At t1, the first processing unit 4 sends the input information to the display circuit 8 and operates as shown in d of FIG.
Rewrite as. Then, the second processing unit 7 is activated at t = t71 as shown in c of FIG. 29 only when an input accompanied by a large process comes at t7.

At t = t7, the second processing section 7 sends an activation command to activate the display circuit 8 to rewrite the display section 2. In the third embodiment, when there is an input / output via communication or the like, the second processing unit 7 does not operate for an input that does not involve a large process,
The first processing unit 4 or the input / output unit 50 performs input / output processing and display processing. Therefore, there is a power saving effect during the input / output operation.

Since the solar cell is used in the fourth embodiment, the power consumption is further reduced and there is an effect that it can be used for a long time.

There is a side in which the solar cell does not operate when there is no light. However, by disposing the solar cell 60 on the same surface as the display section 2, when the solar cell does not operate, the display section 2 does not operate.
Neither the contents of the display nor the keyboard keys can be seen.

Therefore, in reality, there is no problem. In a dark environment, for example, in the case of WP input at a lecture during a slide show, the power supply holding circuit is activated by key input.
The processing unit 4 operates.

(Embodiment 5) FIG. 30 shows a block diagram of a fifth embodiment, in which a solar cell 60 is added as a power source. Since the first processing unit 4 has a low speed, the power consumption is extremely small. Therefore, it can be driven by a solar cell. Although the operation is almost the same as in Example 1, but in the case of a solar cell, the power supply is stopped when the amount of incident light decreases. When stopped, the power supply unit 61 first switches to the power supply. When the key input and the power supply from the solar cell 60 are lost for a long time, the power supply stop mode is entered as shown at t = t61 in FIG. 31B, and the first processing unit 4 saves the processing information in the first memory 5. To stop the operation. In this case the power consumption is reduced. Then, at t = t71, the solar cell 6
When power is supplied from 0 or when there is a key input from the information input unit 3, the operation is started, and the original operation is restarted by the key input at t72.

An example of a method of activating the first processing section 4 by key input will be described here. As shown in FIG. 32, the key input section 62 of the information input section 3 holds the voltage from the battery 64 by the holding circuit 6.
Send to 3. Therefore, when the key is pressed, the holding circuit 63 sends power to the first processing unit 4 to activate the first processing unit 4.
At this time, in parallel, the key input unit 62 sends the key input information to the first key input information.
It is sent to the processing unit 4, and the processing is restarted. FIG. 33 is a block diagram when the first processing unit 4 and the second processing unit 7 are shared.

In this case, in the key input section 62, each key may have two kinds of power source SW and key input SW.

The fifth embodiment is intended to further reduce power consumption. The design also enables notebook computers that do not require battery replacement for several years. In addition, as shown in FIG. 33, the first processing unit and the second processing unit may be combined into one in each of the first to fifth embodiments.

(Example 6) Example 6 is 8 mm CD-RO.
This is a case where the present invention is applied to an information processing apparatus using an optical disk such as M.

FIG. 34 is a block diagram. The information input block 97 includes a CD-ROM drive 3 of a CD-ROM.
01 and the keyboard 201 are connected.

FIG. 35 is a perspective view. The CD-ROM player 312 includes a keyboard 201 and a liquid crystal 208CD-R.
When the optical disc 315 such as OM is inserted into the optical disc insertion unit 316, a activation signal is generated in the activation unit 221 in FIG. 34, and the second processing unit 7 is activated.

In addition, the code signal is sent from the first processing unit 4 to the activation unit 221 by the input from the keyboard 201, the second processing unit 7 is activated, and the second processing unit 7 is stopped after the processing is completed. It is similar to the embodiment of.

This feature extends the battery usable time of portable equipment such as a CD-ROM player due to power consumption. Particularly, the feature of this embodiment is that the activation unit 221 is activated in response to the insertion signal from the CD drive 301, and C
The second processing unit 7 is activated by inserting or removing the optical disc 315 such as a D-ROM.

(Embodiment 7) Embodiment 7 shows a case where the present invention is applied to a digital tape recorder. 36 and 37 show an application example of a digital audio tape recorder 312 such as a DAT, and a liquid crystal 208 and a cassette insertion port 314.
With. By inserting the digital audio tape 313 into the cassette insertion slot 314, as shown in the block diagram of FIG. 36, an activation signal 221 is issued via the first processing unit 4 by the insertion signal from the digital tape drive 311.
To the second processing unit 7 and the second processing unit 7 is activated.

Since the second processing section 7 is started and stopped when the digital audio tape 313 is taken in and out, there is an effect that the operation is started in conjunction with the tape taking in and out by the operator.

According to our simulation calculation, W
If the average power consumption of 5 W is obtained by operating the P software without using the present invention, it becomes several tens mw by using the present invention. Therefore, even a conventional secondary battery can be used for several hundred hours, and a primary battery such as a highly efficient lithium battery can be used for 1000 hours or more.
In other words, even if it is used for 5 hours a month, it can be used as a notebook computer for more than a year, and can be used for a long time without changing batteries like a pocket calculator. At this time, the development direction is also increasing and the number of pixels is increasing. The user is freed from the trouble of charging. The present invention frees the notebook computer from the power cord and charger. Conventionally, regarding the application of ferroelectric liquid crystal, attention has been paid to high speed and high resolution. The focus of the present invention is on the aspect of power consumption reduction, which has hitherto not received much attention in ferroelectric liquid crystals.

This kind of focus has never been seen before, and it is highly effective in reducing power consumption of high-performance portable information equipment such as notebook computers, which are expected to grow in the future.

Although ferroelectric liquid crystal was used as an example of a display element having a memory effect, it can be used as another memory type display element such as a smectic liquid crystal or an electrochromic display element. Although an example of the liquid crystal is a simple matrix drive type liquid crystal, a TFT liquid crystal drive can also be used.

[0121]

As described above, according to the present invention, the power of the main processing unit is stopped at the same time when the main processing unit is stopped at the time when it is detected that the unused state has continued for a certain period of time or when the main processing is completed. An information processing device for continuing display can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of an information processing device according to a first embodiment of the present invention.

FIG. 2 is a timing chart of the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a display unit according to an embodiment of the present invention.

FIG. 4 is a sectional view showing the operating principle of the display unit according to the embodiment of the present invention.

FIG. 5 is a screen diagram of a display unit according to the embodiment of the present invention.

FIG. 6 is a flowchart for explaining the operation in the embodiment of the present invention.

FIG. 7 is a block diagram showing the configuration of a specific embodiment of the present invention.

FIG. 8 is another block diagram showing the configuration of a specific embodiment of the present invention.

FIG. 9 is another block diagram showing the configuration of a specific embodiment of the present invention.

FIG. 10 is a flow chart explaining the operation in a specific embodiment of the present invention.

FIG. 11 is another block diagram according to a specific embodiment of the present invention.

FIG. 12 is a diagram illustrating the principle of operation of a reflective element according to an embodiment of the present invention.

FIG. 13 is a diagram showing the principle of operation of the reflector in the embodiment of the present invention.

FIG. 14 is an operation principle diagram of another reflector according to the embodiment of the present invention.

FIG. 15 is a block diagram for explaining a second embodiment of the present invention.

FIG. 16 is a block diagram around the first processing unit in the second embodiment of the present invention.

FIG. 17 is a block diagram around another second processing unit in the embodiment of the present invention.

FIG. 18 is a flowchart for explaining the second embodiment of the present invention.

FIG. 19 is a flowchart for explaining the second embodiment of the present invention.

FIG. 20 is a timing chart for explaining the second embodiment of the present invention.

FIG. 21 is a cursor display state diagram for explaining the second embodiment of the present invention.

FIG. 22 is a front view of a display unit during a translation process for explaining the second embodiment of the present invention.

FIG. 23 is a front view of a display unit for additional input for explaining the second embodiment of the present invention.

FIG. 24 is a display diagram in the copy mode for explaining the second embodiment of the present invention.

FIG. 25 is a block diagram of a modification for explaining the second embodiment of the present invention.

FIG. 26 is a block diagram for explaining a third embodiment of the present invention.

FIG. 27 is a flowchart for explaining the third embodiment of the present invention.

FIG. 28 is a block diagram for explaining the fourth embodiment of the present invention.

FIG. 29 is a timing chart for explaining the fourth embodiment of the present invention.

FIG. 30 is a block diagram for explaining a fifth embodiment of the present invention.

FIG. 31 is a timing chart for explaining the fifth embodiment of the present invention.

FIG. 32 is a block diagram of an information unit input unit for explaining a fifth embodiment of the present invention.

FIG. 33 is a block diagram when the first processing unit and the second processing unit are used in combination for explaining the fifth embodiment of the present invention.

FIG. 34 is a block diagram for explaining the sixth embodiment of the present invention.

FIG. 35 is a perspective view for explaining the sixth embodiment of the present invention.

FIG. 36 is a block diagram for explaining the seventh embodiment of the present invention.

FIG. 37 is a perspective view for explaining the seventh embodiment of the present invention.

[Explanation of symbols]

1 First processing block 2 Display 3 Information input section 4 First processing unit 5 First memory section 6 Interruption control unit 7 Second processing unit 8 Display circuit section 9 Second memory 11 Horizontal drive section 12 Vertical drive section 20 power switch 24 heater 25 backlight 26 Reflection circuit 27 Reflective element 30 openings 32 incident light 33 reflected light 34 Reflective plate 40 First font ROM 43 Second font ROM 82 video memory 98 Second processing block 99 display blocks 201 keyboard 202 floppy disk controller 204 ROM 205 backup RAM 206 graphic controller 207 LCD controller / driver 208 LCD 209 bus

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shozo Fujiwara 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Tsuyoshi Uemura 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (56) References JP-A 61-288725 (JP, A) JP-A 1-118915 (JP, A) JP-A 59-107380 (JP, A) Actual development Sho-56-102576 (JP, U) 62-167466 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/133 G02F 1/1335 G02F 1/13357 G02F 1/1343 G02F 1/13 505 G09G 3 / 36

Claims (7)

(57) [Claims] 1. A liquid crystal display device including a backlight, a liquid crystal display unit, and an information input unit for inputting information from the outside, wherein the liquid crystal display unit displays by a transmitted light from the backlight. Display is performed by a transmissive mode to be performed and a reflective mode in which display is performed by reflected light of external light, and when the input of the information input unit is not made for a certain period of time, the backlight is turned off, and the liquid crystal display unit is in a reflective mode. An information processing device characterized by displaying. 2. The information processing apparatus according to claim 1, wherein the information input unit inputs external information from a user. 3. The information processing apparatus according to claim 1, wherein the information input unit inputs external information from a communication interface. 4. The information processing apparatus according to claim 2, wherein the information processing apparatus is a battery-powered portable information processing apparatus. 5. The information processing apparatus according to claim 1, wherein the backlight is turned off when there is no input from the information input unit for a certain period of time and the processing frequency of the CPU is low. 6. The information processing apparatus can be driven by two power sources, an external power source and a battery. When the external power source is used, the backlight is turned on to display in a transparent mode, and the battery is used. In this case, the information processing apparatus according to any one of claims 1 to 5, wherein the backlight is turned off and display is performed in a reflection mode. 7. The liquid crystal display unit is provided with a reflection layer and a liquid crystal layer on the display side with respect to the backlight, and the reflection layer reflects incident light incident from the display side through the liquid crystal layer. The reflective layer has a plurality of openings, the light from the backlight is transmitted through the openings, and the transmitted light is transmitted through the openings. The information processing apparatus according to claim 1, wherein the information processing apparatus is configured so as to emerge from the display side through the liquid crystal layer.