JP5780079B2 - Electronic paper information terminal - Google Patents

Description

  The present invention relates to an information terminal using electronic paper, and more particularly to its power supply technology.

  Electronic paper does not require a backlight, is a reflective display device similar to paper, has a viewing angle close to 180 degrees, has a higher contrast than newspaper, and does not depend on the brightness of the external environment In addition, in recent years, as a terminal display panel for electronic books, a microcapsule-type electronic flow method or the like has been characterized. An electronic powder fluid type electronic paper has been put into practical use.

  A common driving method for these electronic papers is that one side of the panel is a common ground, the other electrode is arranged according to the screen resolution, and a positive or negative voltage is applied to the electrode, so that the electronic paper is Display is realized by moving certain colored particles. For this electrode, a wiring disposed on the back surface of the panel or a TFT matrix for driving an LCD panel or the like is used. In some cases, a secondary battery that can be charged and discharged is used as a power source (see, for example, Patent Document 1).

  Electronic paper is characterized by holding a display screen. On the other hand, if the screen is held continuously, the agglomeration of particles localized inside the electronic paper and the adsorption force to the wall increase, so-called image sticking occurs. There is a case. Therefore, when the screen is switched, the light / dark switching operation on the entire surface is often performed.

  On the other hand, a secondary battery represented by a lithium ion battery uses an electrochemical reaction, and thus its life is often determined by deterioration of a material used in the battery. Especially in the case of electric field, decomposition is accelerated when exposed to a high temperature in a fully charged state where a high electric field is applied, so that components related to ion movement in the battery decrease, and the battery capacity decreases. There is a tendency. Further, if the current value that can be supplied with respect to the battery capacity is increased, the deterioration of the battery is accelerated.

JP 2010-244061 A

  The contents displayed on the electronic paper information terminal are books, newspapers, magazines, advertisements, etc., which are basically purchased by the user and have no confidential information. It is considered that the problem hardly occurs with respect to the display contents. On the other hand, in the case of business correspondence such as that used in a meeting in a company, etc., secret information is basically included in many cases, and security measures for preventing the outflow of information are important. In addition, when used in a company or the like, there is a purpose of reducing paper materials, and there is a high possibility that it will be used frequently. Electronic paper and secondary batteries required for driving the electronic paper also require a long life.

  The present invention has been made in view of the problems of the above-described technology, and provides an electronic paper information terminal capable of extending the life of the electronic paper and the built-in battery and ensuring high security. The purpose is to do.

In order to achieve the above object, the present invention provides:
An electronic paper capable of holding a display pattern of two colors even when power supply is cut off, a driver for driving the electronic paper, a power source for supplying power for driving the driver, and the electronic paper A memory for holding information corresponding to a display pattern to be displayed; and the driver using power supplied from the power source so that a display pattern according to the information held in the memory is displayed on the electronic paper. In an electronic paper information terminal having a controller to control,
The power supply is
Timer,
A rechargeable secondary battery;
A voltage monitoring monitor for monitoring the voltage of the secondary battery,
The controller has two colors on the entire surface of the electronic paper by supplying pulsed power to the electronic paper using the power of the secondary battery after the time measured by the timer has elapsed in advance. When the minimum voltage of the secondary battery monitored by the voltage monitoring monitor falls below a specified voltage value, the two-color switching operation on the entire surface of the electronic paper is stopped at the intermediate color of the two colors. And then shut off the power supply from the secondary battery,
The memory is volatile, and stored information is erased when power supply from the secondary battery is cut off.

  As described above, in the present invention, the controller performs the two-color switching operation on the entire surface of the electronic paper by supplying the pulsed power to the electronic paper after the time measured by the timer has elapsed in advance. When the minimum voltage of the secondary battery falls below a specified voltage value, the two-color switching operation on the entire surface of the electronic paper is stopped at the intermediate color of the two colors, and then the power supply from the secondary battery is shut off. By doing so, it is possible to prevent burn-in of the display screen with electronic paper and maintain its quality over a long period of time, and for secondary batteries, discharge to a fixed amount of electricity each time at a level that does not cause overdischarge. By doing so, the voltage between cells at the time of storage can be lowered, the decomposition of the electrolytic solution is suppressed, and the battery life can be extended. Further, when the memory is volatile and the power supply from the secondary battery is cut off, the stored information is erased, so that high security can be ensured.

It is a block diagram which shows one Embodiment of the electronic paper information terminal of this invention. It is a figure for demonstrating the refresh operation | movement of the electronic paper shown in FIG. It is a figure which shows the voltage of the secondary battery at the time of performing pulse-shaped electric power supply with respect to the electronic paper shown in FIG. 1, (a) is a figure which shows a drive pulse, (b) is the voltage of a secondary battery. FIG. It is a figure which shows an example of the pulse-shaped electric power supply with respect to the electronic paper shown in FIG. 1, (a) is a figure which shows a drive pulse, (b) is a figure which shows the voltage of a secondary battery. It is a figure which shows the other example of the pulse-shaped electric power supply with respect to the electronic paper shown in FIG. 1, (a) is a figure which shows a drive pulse, (b) is a figure which shows the voltage of a secondary battery. It is a block diagram which shows other embodiment of the electronic paper information terminal of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing an embodiment of an electronic paper information terminal of the present invention.

  As shown in FIG. 1, the present embodiment includes an electronic paper 2, a driver 3, a controller 4, a memory 5, a scroll key 6, a timer setting key 7, and a power supply 10.

  The electronic paper 2 can hold a black / white two-color display pattern even when power supply is cut off.

  The driver 3 is connected to the electronic paper 2, the controller 4, and the power supply 10, and drives the electronic paper 2.

  The controller 4 is connected to the driver 3, the memory 5, the scroll key 6, the timer setting key 7 and the power supply 10, reads information held in the memory 5, and a display pattern corresponding to this information is displayed on the electronic paper 2. Thus, the driver 3 is controlled using the power supplied from the power source 10.

  The memory 5 is loaded with image data serving as information corresponding to the display pattern displayed on the electronic paper from the outside, and holds the image data.

  The power supply 10 includes a chargeable / dischargeable secondary battery 11, a timer 12, a voltage monitoring monitor 13 that monitors the voltage of the secondary battery 11, and a voltage converter 14, and drives all components such as the driver 3. It supplies power to do this. Note that the negative electrode of the secondary battery 11 has the same potential as the negative electrode of the controller 4 and is provided on the same substrate.

  Below, operation | movement of the electronic paper information terminal 1 comprised as mentioned above is demonstrated.

  First, an operation when displaying information on the electronic paper 2 will be described.

  Image data for displaying a display pattern on the electronic paper 2 is loaded into the memory 5 from the outside, and at the same time, the secondary battery 11 in the power supply 10 is charged. In this case, the security can be improved by charging the secondary battery 11 with a charger having an authentication function. Further, in order to limit the usage time, the power supply time is set in the timer 12 via the timer setting key 7.

  Thereafter, when the image data is actually displayed on the electronic paper 2, the image data loaded in the memory 5 is loaded onto the controller 4, and the controller 4 converts the image data into a display pattern on the electronic paper 2. The driver 3 is driven under the control of the controller 4, and the display pattern is displayed on the electronic paper 2 by applying a voltage to the electrodes of the electronic paper 2 by the driver 3.

  The page turning of the display pattern displayed on the electronic paper 2 is performed under the control of the controller 4 by operating the scroll key 6.

  Next, an operation after the use time set in the timer 12 expires will be described.

  In the timer 12, the time from the start of use is measured, and when the measured time passes the use time set in the timer 12, the display pattern display on the electronic paper 2 is controlled by the control of the controller 4. The display ends automatically, light / dark display (voltage plus / minus application) of the electronic paper 2 is started by supplying pulsed power, and the refreshing operation is performed by vibrating the colored particles in the electronic paper 2. Specifically, both sides of the electronic paper 2 are made to be equipotential, and stop in a state where the colored particles are not biased to either wall surface.

  FIG. 2 is a diagram for explaining a refresh operation of the electronic paper 2 shown in FIG.

  In the refresh operation of the electronic paper 2, first, the colored particles in the electronic paper 2 are attracted to one of the electrodes on the screen side or the drive electrode side by the control of the controller 4 as shown in FIG. Thus, black is displayed on the entire surface of black / white displayed on the electronic paper 2, and then the colored particles in the electronic paper 2 are attracted to the other electrode on the screen side or the drive electrode side, As shown in FIG. 2 (b), white of black / white displayed on the electronic paper 2 is displayed on the entire surface, and then the both sides of the electronic paper 2 are made equipotential so that either colored particle is present. As shown in FIG. 2 (c), a black / white intermediate gray color displayed on the electronic paper 2 is displayed on the entire surface as a state not biased toward the wall surface.

  The secondary battery 11 in the power supply 10 is gradually discharged by this pulsed power supply, and when the voltage of the secondary battery 11 falls below the minimum voltage which is a specified voltage value by the voltage monitoring monitor 13, the power supply 10. The power supply to the display system of the electronic paper 2 is cut off in the state shown in FIG. At this time, if the memory 5 holding the image data is volatile, the image data is also erased.

  By starting, operating, and stopping as described above, the electronic paper 2 can perform a refresh operation and discharge the secondary battery 11. As a result, the display quality of the electronic paper 2 can be maintained and the secondary battery 11 can be stored in a low capacity / low voltage state, so that deterioration of the secondary battery 11 can be suppressed. Furthermore, since the image data including the secret information has been erased, there is no possibility of information leakage even if it is taken outside as it is.

  Below, the power supply control method at the time of the pulse-shaped electric power supply mentioned above is demonstrated in detail.

  FIG. 3 is a diagram illustrating the voltage of the secondary battery 11 when pulsed power is supplied to the electronic paper 2 illustrated in FIG. 1, (a) is a diagram illustrating drive pulses, and (b) FIG. 3 is a diagram showing the voltage of the secondary battery 11.

  In the secondary battery 11, since it is difficult to strictly follow at least ON / OFF of the millisecond order, when a relatively large current is applied by a driving pulse as shown in FIG. Has a large instantaneous voltage drop, and even if the discharge is stopped below the lower limit of the voltage, as shown in FIG. 3B, the voltage tends to recover considerably.

  FIG. 4 is a diagram illustrating an example of pulsed power supply to the electronic paper 2 illustrated in FIG. 1, (a) is a diagram illustrating a drive pulse, and (b) is a diagram illustrating a voltage of the secondary battery 11. is there.

  As shown in FIG. 4A, in the controller 4, after the time measured by the timer 12 has passed a preset time, in the initial stage of the display stop operation in the electronic paper 2, the pulse drive pulse As shown in FIG. 4 (b), when the width is widened, and then the pulsed power is supplied to the electronic paper 2 so that the pulse width gradually decreases as the voltage of the secondary battery 11 decreases. The stop voltage of the secondary battery 11 can be made to reach a more accurate voltage. In this case, since the number of times the lower limit voltage is lowered by pulse driving can be suppressed as compared with the case of driving at a constant pulse interval, it is possible to further suppress deterioration of the secondary battery 11.

  FIG. 5 is a diagram illustrating another example of pulsed power supply to the electronic paper 2 illustrated in FIG. 1, where (a) illustrates a drive pulse, and (b) illustrates a voltage of the secondary battery 11. FIG.

  As shown in FIG. 5 (a), in the controller 4, after the time measured by the timer 12 has passed a preset time, the pulsed power supply to the electronic paper 2 is performed for a predetermined time at a predetermined timing. If the control is performed in consideration of the voltage recovery time and the number of times the lower limit voltage is dropped by pulse driving can be further suppressed, the stop operation can be safely completed. Also, when performing such pulse driving, if an organic radical battery that can discharge a large current with respect to the battery capacity, has a short battery voltage recovery time, and can be designed to have a relatively small battery capacity, The stop operation can be completed in a relatively short time.

(Other embodiments)
FIG. 6 is a block diagram showing another embodiment of the electronic paper information terminal of the present invention.

  In this embodiment, as shown in FIG. 6, an input information recording device 8 is superimposed on the surface of the electronic paper 2 with respect to that shown in FIG. 1, and a nonvolatile memory in addition to a volatile memory 5 is used. 9 is different.

  The input information recording device 8 is used when information such as a comment or a chart is added to the image information displayed on the electronic paper 2, and is typically a resistive touch panel or an electrostatic For example, a capacitive touch panel may be used.

  The controller 4 may store the information input to the input information recording device 8 by appending in the volatile memory 5 if it may be finally deleted, and it is necessary to leave the information. Can be recorded in a non-volatile memory 9 such as an EEPROM, and thereafter the data can be transferred to the outside, thereby achieving its purpose.

  Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the configuration of the above embodiment, and various modifications that can be made by those skilled in the art within the scope of the present invention. Of course, including modifications.

DESCRIPTION OF SYMBOLS 1,101 Electronic paper terminal 2 Electronic paper 3 Driver 4 Controller 5,9 Memory 6 Scroll key 7 Timer setting key 8 Input information recording device 10 Power supply 11 Secondary battery 12 Timer 13 Voltage converter

Claims (7)

An electronic paper capable of holding a display pattern of two colors even when power supply is cut off, a driver for driving the electronic paper, a power source for supplying power for driving the driver, and the electronic paper A memory for holding information corresponding to a display pattern to be displayed; and the driver using power supplied from the power source so that a display pattern according to the information held in the memory is displayed on the electronic paper. In an electronic paper information terminal having a controller to control,
The power supply is
Timer,
A rechargeable secondary battery;
A voltage monitoring monitor for monitoring the voltage of the secondary battery,
The controller has two colors on the entire surface of the electronic paper by supplying pulsed power to the electronic paper using the power of the secondary battery after the time measured by the timer has elapsed in advance. When the minimum voltage of the secondary battery monitored by the voltage monitoring monitor falls below a specified voltage value, the two-color switching operation on the entire surface of the electronic paper is stopped at the intermediate color of the two colors. And then shut off the power supply from the secondary battery,
The electronic paper information terminal, wherein the memory is volatile, and stored information is erased when power supply from the secondary battery is cut off. The electronic paper information terminal according to claim 1,
The controller is an electronic paper information terminal that supplies pulsed power to the electronic paper so that a pulse width is gradually narrowed after a predetermined time has elapsed by the timer. The electronic paper information terminal according to claim 1,
The electronic paper information terminal, wherein the controller stops the pulsed power supply to the electronic paper for a predetermined time at a predetermined timing after the time measured by the timer has elapsed in advance. The electronic paper information terminal according to any one of claims 1 to 3,
An input information recording device capable of inputting information to the display screen of the electronic paper;
A non-volatile memory,
The controller records information input to the input information recording device in the nonvolatile memory;
An electronic paper information terminal configured such that information recorded in the nonvolatile memory can be transferred to the outside. The electronic paper information terminal according to any one of claims 1 to 4,
The negative electrode of the secondary battery is the same potential as the negative electrode of the controller, and is an electronic paper information terminal provided on the same substrate. The electronic paper information terminal according to any one of claims 1 to 5,
The secondary battery is an electronic paper information terminal which is an organic radical battery. The electronic paper information terminal according to any one of claims 1 to 6,
The secondary battery is an electronic paper information terminal that is charged by a charger having an authentication function.

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