JP2019090934A - Driving device, method for driving electronic display medium, and display device - Google Patents

Abstract

To reduce the time it takes to send required electric power to a power storage unit of a driving device to rewrite the display of an electronic display medium, using self-generated electric power.SOLUTION: There is used the driving device including: a controller; a self-generator for generating electric power; the power storage unit for supplying electric power generated by the self-generator and stored, to the driving device; and a display driving unit for applying a driving signal to the electronic display medium. The display driving unit has a booster circuit for increasing the voltage supplied from the power storage unit to generate the driving signal. The controller makes the booster circuit stop during a charging time when electric power is being stored in the power storage unit, and makes the booster circuit operate during a rewriting time when the driving signal is being applied to the electronic display medium.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a drive device, a method of driving an electronic display medium, and a display device.

  BACKGROUND ART Conventionally, a technology related to an electronic device using an electronic display medium having a memory property such as an electrophoretic display element is known (see, for example, Patent Document 1). Although an electronic display medium having memory properties requires power at the time of rewriting of display, it can hold display contents without requiring power after rewriting, so that power consumption can be suppressed. In the technology disclosed in Patent Document 1, power is supplied to a microcomputer and a driver IC by a power supply generated contactlessly by electromagnetic induction.

  By the way, there exist technologies called energy harvesting and environmental power generation that can convert energy such as sunlight, vibration, and heat into electric energy and drive various electronic devices and devices. Power consumption can be further reduced by using a display medium having a memory property in an electronic display device that performs display rewriting using self-generated power.

JP, 2014-002694, A

  When rewriting the display of the electronic display medium using the self-generated power, it is necessary to temporarily store the self-generated power in a storage unit such as a capacitor. However, when the power generation capacity is not sufficient, there is a problem that it takes a lot of time to charge necessary power.

  The present invention has been made to solve the above problems, and an object thereof is to provide a driving device, a method of driving an electronic display medium, and a method capable of shortening the time for charging self-generated power to a storage unit. It is an object to provide a display device.

In order to solve the above problems, the present invention is a drive device for driving an electronic display medium,
A control unit that controls the drive device;
A self-generation unit that generates electricity,
A storage unit that stores the power generated by the self-generation unit and supplies the power to the drive device;
A display drive unit for applying a drive signal to the electronic display medium;
Equipped with
The display drive unit includes a booster circuit that boosts a voltage supplied from the storage unit to generate the drive signal;
The control unit stops the boosting circuit during a charging period in which power is stored in the storage unit, and operates the boosting circuit during a rewriting period in which the drive signal is applied to the electronic display medium. Drive device.

The present invention is also a drive device for driving an electronic display medium,
A control unit that controls the drive device;
A self-generation unit that generates electricity,
A storage unit that stores the power generated by the self-generation unit and supplies the power to the drive device;
A display drive unit for applying a drive signal to the electronic display medium;
Equipped with
The display drive unit includes a switching type booster circuit that boosts the voltage supplied from the storage unit at a predetermined boosting frequency to generate the drive signal.
The control unit sets the boosting frequency of the boosting circuit to a low frequency during a charging period in which power is stored in the storage unit, and the boosting frequency during a rewriting period in which the drive signal is applied to the electronic display medium. It is a drive device characterized by using a high frequency.

Further, the present invention is the above-described drive device, wherein
A voltage measurement unit that measures a storage voltage of the power stored in the storage unit;
The voltage measurement unit transmits the stored voltage to the control unit.
The control unit may start the rewriting period when the stored voltage reaches a predetermined voltage.

The present invention is also a driving method of an electronic display medium including a driving device,
A control unit that controls the drive device, a self-power generation unit that generates power, and a storage unit that stores the power generated by the self-power generation unit and supplies the power to the drive device; A display drive unit for applying a drive signal to an electronic display medium, the display drive unit having a booster circuit for boosting a voltage supplied from the storage unit in order to generate the drive signal;
Stopping the boosting circuit during a charging period in which power is stored in the storage unit;
And a step of operating the booster circuit during a rewrite period in which the drive signal is applied to the electronic display medium.

  In addition, the display device of the present invention may include the above-described drive device.

  In the display device of the present invention, the electronic display medium may have a plurality of display areas.

  According to the present invention, the consumption of power by the booster circuit can be suppressed during the charging period of the storage unit, so that the time required for charging the storage unit with the self-generated power can be shortened.

It is a figure which shows schematic structure of the drive device by the 1st Embodiment of this invention. It is sectional drawing for demonstrating the principle of operation of an electronic display medium. It is a flowchart which shows the drive processing of the 1st Embodiment of this invention. FIG. 6 is a timing diagram from when power generation starts to when the power is discharged in the first embodiment of the present invention. It is a figure which shows schematic structure of the drive device by the 2nd Embodiment of this invention. It is a flowchart which shows the drive processing of the 2nd Embodiment of this invention. It is a figure which shows schematic structure of the drive device by the 3rd Embodiment of this invention. In the 3rd embodiment of the present invention, it is a timing diagram from the start of power generation until the power is discharged.

First Embodiment
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

(Schematic configuration)
FIG. 1 is a view showing a schematic configuration of a drive device 100 for driving an electronic display medium 200 having a memory property such as electronic paper in the present embodiment. The pixels of the electronic display medium 200 can display two colors, and in this embodiment, display two colors of white and black. The drive device 100 includes a trigger output unit 10, a self power generation unit 20, a storage unit 30, a control unit 40, a non-volatile memory 50, a display drive unit 60 such as a driver IC, and a reset unit 70.

  The driving device 100 can display an image on the electronic display medium 200. For example, when the electronic display medium 200 is provided in a remote control device, an image such as a television channel display or an air conditioner temperature display can be displayed. .

(Trigger output unit 10)
The trigger output unit 10 is an operation unit on which an operation to trigger rewriting of an image displayed on the electronic display medium 200 is performed.

  When the trigger output unit 10 is operated, operation information of the trigger output unit 10 is notified to the control unit 40. For example, when the trigger output unit 10 is in the form of a push button, an instruction to switch the image displayed on the electronic display medium 200 is notified to the control unit 40 each time the push button is pressed.

(Self-power generation unit 20)
The self power generation unit 20 generates power by being operated. The generated power is stored in power storage unit 30. The self-power generation unit 20 can be in various forms according to the situation in which it is provided. For example, power may be generated by applying external energy such as vibration or heat, or a method of rotating a rotating body by pressing a push button and absorbing energy of the rotating body by electromagnetic induction to generate a voltage Alternatively, a method of generating a voltage by a piezoelectric element can be employed.

  In addition, the self power generation unit 20 may be integrally formed with the trigger output unit 10. For example, if the push button and the above power generation method are combined in the form of the push button in the form of the push button, power is generated using the energy given to the trigger output unit 10 when the trigger output unit 10 is operated. Can.

  In the present embodiment, a case where the trigger output unit 10 and the self-power generation unit 20 are integrally formed as a push button will be described. Therefore, in the description of the present embodiment, when it is described that the trigger output unit 10 is operated, it is understood that the self-power generation unit 20 is also operated at the same time.

(Electric storage unit 30)
Power storage unit 30 accumulates the power generated by self power generation unit 20 and supplies power to each unit of drive device 100. Power storage unit 30 includes, for example, a capacitor and a regulator. The stored power is supplied to the drive device 100 after being reduced to a constant voltage or less by the regulator.

(Reset unit 70)
The reset unit 70 is configured by an analog IC, and outputs a reset release signal to the control unit 40 when the voltage of the power stored in the storage unit 30 becomes equal to or higher than a predetermined value defined by the analog IC. The reset state of the control unit 40 is released, and the operation of the control unit 40 is started. The control unit 40 is in the reset state in the initial state, and starts the operation by receiving a reset release signal from the reset unit 70.

  In the case of power generation by self power generation, the increase in voltage may become unstable immediately after the start of power supply from the self power generation unit 20, and the operation of the calculation means of the control unit 40 may become unstable or runaway. There is a risk of Therefore, control is performed by providing reset unit 70 and outputting a reset release signal to control unit 40 after the voltage supplied from power storage unit 30 becomes equal to or higher than the voltage required to perform a stable operation. The part 40 can be stably and reliably started to operate.

  The reset unit 70 may be configured as one module integrated with the control unit 40.

(Non-volatile memory 50)
The non-volatile memory 50 is a rewritable non-volatile storage medium, and includes, for example, a flash memory or FRAM (registered trademark) (ferroelectric memory), and the non-volatile memory 50 stores image information described later. .

  In addition, the non-volatile memory 50 may be incorporated in a part of the integrated circuit of the control unit 40 and configured as a part of the control unit 40.

(Control unit 40)
The control unit 40 controls each unit of the drive device 100. The control unit 40 includes a processing unit (CPU: Central Processing Unit) (not shown), a volatile storage unit (RAM: Random Access Memory) that can read and write, and a storage unit 41, and performs processing according to the program stored in the storage unit 41. Run. The storage unit 41 is a rewritable non-volatile storage medium (EPROM, OTP-EPROM, flash memory, etc.) or a read-only non-volatile storage medium (ROM: Read Only Memory). Remember.

  The storage unit 41 may be integrally incorporated in the integrated circuit of the control unit 40 as a part of the integrated circuit of the control unit 40.

(Display drive unit 60)
In order to generate a drive signal, display drive unit 60 includes a booster circuit 61 for boosting a voltage supplied from storage unit 30, an image buffer 62 for storing current image information and new image information to be displayed, and each pixel. An arithmetic circuit 64 for determining a drive waveform to be output and a driver circuit 63 for selecting the drive waveform are provided, and a predetermined drive signal is applied to the electronic display medium 200.

  When the display drive unit 60 applies a drive signal to the electronic display medium 200, the current image displayed on the electronic display medium 200 is rewritten to the image of the new image information.

  In the display drive unit 60 of this embodiment, an input voltage of around 3 V is boosted (and inverted) to ± 15 V by the booster circuit 61, and a driver circuit 63 displays electronic voltage of 0 V, +15 V and -15 V three values. A three-value driving driver IC applied to the medium 200 is used.

  The arithmetic circuit 64 compares the current image information with the new image information. The arithmetic circuit 64 compares (1) whether it changes from white to black, (2) whether it changes from black to white, or (3) does not change white for each pixel according to the comparison here. (4) It is determined whether it remains black, and the output waveform of the drive signal to each pixel is determined.

  The driver circuit 63 outputs a drive signal corresponding to the comparison result of the arithmetic circuit 64 to each pixel of the electronic display medium 200 for a predetermined period.

  The image buffer 62, the arithmetic circuit 64, the booster circuit 61, and the driver circuit 63 of the display drive unit 60 can also be configured as different modules.

(Electronic display medium 200)
FIG. 2 is a cross-sectional view for explaining the operating principle of the electronic display medium 200 of electrophoretic electronic paper in which charged particles move by electrophoresis. In FIG. 2, a transparent solvent 260 such as an upper electrode 210, a lower electrode 220, microcapsules 230, white particles 240, black particles 250, and oil is shown. The electronic display medium 200 of FIG. 2 is observed from the observation direction A (upper electrode 210 side).

  As shown in FIG. 2, the electronic display medium 200 made of electrophoretic electronic paper is composed of negatively charged white particles 240 and positively charged black particles in a transparent solvent 260 of microcapsules 230 having a diameter of about 40 μm. Particles 250 are contained. The upper electrode 210 is a common electrode formed of a transparent electrode such as an ITO (oxide indium tin oxide) film. The lower electrode 220 is a pixel electrode provided for each pixel area of one segment formed of metal foil or the like.

  When a voltage of 0 V is applied to the upper electrode 210 and the lower electrode 220 is set to -15 V, the negatively charged white particles 240 move upward in the transparent solvent 260 by electrophoresis, and the positively charged black particles 250 are lowered. Since it moves to the side, it looks white when viewed from the observation direction A.

  When a voltage of +15 V is applied to the lower electrode 220 and the upper electrode 210 is set to 0 V, the negatively charged white particles 240 move downward in the transparent solvent 260 by electrophoresis, and the positively charged black particles 250 are on the upper side. It looks black when viewed from the observation direction A.

  After that, even if the difference in applied voltage between the upper electrode 210 and the lower electrode 220 is 0 V, the electronic display medium 200 holds that state by the intermolecular force between the particles and between the particles and the microcapsule interface, Keep displaying the same color.

(Operation procedure)
Next, the procedure of image rewriting of the electronic display medium 200 will be described.

  When activated, the control unit 40 starts measuring time. Further, the control unit 40 activates the display drive unit 60. At that time, the control unit 40 transmits a command to stop the operation of the booster circuit 61 to the display drive unit 60, and turns the booster circuit 61 OFF. Further, the control unit 40 inputs initial values of various registers such as an operation clock and drive waveform data as initial setting of the display drive unit 60, and initializes the display drive unit 60.

  Next, the control unit 40 reads current image information from the non-volatile memory 50 and writes the current image information in the current image buffer of the image buffer 62 of the display drive unit 60. Thereafter, the electronic display medium 200 writes new image information indicating an image to be displayed next to the new image buffer of the image buffer 62. Then, the control unit 40 transmits, to the display drive unit 60, a drive signal application command instructing to rewrite the display of the electronic display medium 200.

  When receiving the drive signal application command, the display drive unit 60 applies a drive signal to the electronic display medium 200 according to the calculation result performed by the calculation circuit 64 based on the information written in the image buffer 62.

Then, the control unit 40 transmits a command to start the operation of the booster circuit 61 to the display drive unit 60 after the activation and a predetermined time has elapsed, and turns the booster circuit 61 ON.
When transmitting the drive signal application command to the display drive unit 60, the control unit 40 stores the new image information in the non-volatile memory 50. Thereby, the image displayed on the electronic display medium 200 and the image stored in the non-volatile memory 50 can be reliably matched.

  Here, the self-power generation unit 20 generates power to drive the display drive unit 60 stably during a predetermined period from when the control unit 40 starts up to when transmitting a command to start operation to the booster circuit 61. It is the period required for the storage unit 30 to store the power necessary to cause the storage. That is, “before the predetermined period elapses” refers to a charging period in which electric power is stored in power storage unit 30, and “after the predetermined period elapses” corresponds to the charging period during which the drive signal is applied to electronic display medium 200. Point to

  As described above, when the control unit 40 switches ON and OFF of the booster circuit 61, the booster circuit 61 can be stopped during the charging period, and the booster circuit 61 can be operated during the rewriting period. By doing this, power consumption by the booster circuit 61 during the charging period is eliminated, and therefore, accumulation of power in the storage unit 30 can be accelerated. That is, the length of the charging period can be shortened as compared with the case where the booster circuit is operated also during the charging period.

  Next, an example of drive processing performed by the drive device 100 of the first embodiment will be described using the flowchart of FIG. 3.

(Step S1)
First, when the trigger output unit 10 and the self-power generation unit 20 are operated, the self-power generation unit 20 starts power generation, and the power is stored in the power storage unit 30.

(Step S2)
When the voltage of the power stored in power storage unit 30 exceeds the voltage (for example, 1.7 V) that control unit 40 can stably drive, reset unit 70 outputs a reset release signal to control unit 40. Thereby, the reset state of the control unit 40 is released, and the control unit 40 is activated.

(Step S3)
The activated control unit 40 starts measuring time. Further, the control unit 40 activates the display drive unit 60. At that time, the control unit 40 transmits a command to stop the operation of the booster circuit 61 to the display drive unit 60, and turns the booster circuit 61 OFF.

(Step S4)
The control unit 40 inputs the new image information instructed by the user pressing the trigger output unit 10 into the image buffer 62 of the display drive unit 60. Here, when the power is lost, the data of the current image information in the image buffer 62 of the display drive unit 60 is erased. Therefore, when the data of the current image information in the image buffer 62 is erased, the control unit 40 first reads the current image information from the non-volatile memory 50, and transmits the current image information to the current image buffer of the image buffer 62. input.

  Then, next, new image information prepared by the control unit 40 is input to the new image buffer of the image buffer 62 of the display drive unit 60. In practice, the number of buffers that can be input / output is often only one, and the content of the current image information is written to the new image buffer, and the current image information of the new image buffer is copied to the current image buffer. Write new image information to new image buffer.

(Step S5)
The control unit 40 transmits a command to start the operation of the booster circuit 61 to the display drive unit 60 after the predetermined time which has been determined in advance, and turns on the booster circuit 61. In order to increase storage voltage VB of storage unit 30 to a voltage (for example, 3.5 V) necessary for rewriting the image of electronic display medium 200 by the electric power generated by self-generation unit 20 for a predetermined time set in advance. It is the time it takes. The predetermined time is about 1 μ second to 1 second depending on the configurations of the self power generation unit 20 and the power storage unit 30 and how the self power generation unit 20 is pressed.

  Then, after a stabilization time necessary for the voltage of the booster circuit to reach a desired voltage has elapsed, a drive signal application command to the electronic display medium 200 is transmitted to the display drive unit 60. The stabilization time of the booster circuit varies depending on the display drive IC, but is usually 30 to 200 ms.

(Step S6)
The arithmetic circuit 64 of the display drive unit 60 compares the data of the drive signal according to the result of the operation of comparing the current image information stored in the image buffer 62 with the new image information in accordance with the drive signal application command received from the control unit 40. create. The driver circuit 63 of the display drive unit 60 applies a pixel electrode drive voltage pulse to the upper electrode 210 and the lower electrode 220 according to the data of the drive signal generated by the arithmetic circuit 64.

(Step S7)
The control unit 40 checks whether the display drive unit 60 outputs BUSY indicating that the drive signal is being output.

(Step S8)
The control unit 40 determines whether the BUSY output from the display drive unit 60 has ended.

  If the BUSY output from the display drive unit 60 has not ended (step S8: NO), the control unit 40 returns to step S7 again, and checks the end of the BUSY output from the display drive unit 60.

(Step S9)
When the BUSY output from the display drive unit 60 ends (step S8: YES), the control unit 40 stops the display drive unit 60. Thereafter, the storage voltage VB gradually decreases to 0 V due to natural discharge.

  As shown in the process described above, the control unit 40 operates by the reset unit 70 outputting a reset release signal when the stored voltage VB of the supplied power reaches the control unit operating voltage. Start. Then, when the output of the drive signal is completed, the process ends.

  Once the processing is completed, the control unit 40 does not perform the next processing until the state of reset is reached again. As a result, even if the voltage supplied from power storage unit 30 is unstable after the end of the rewriting, erroneous display can be suitably suppressed.

  Subsequently, referring to the timing chart of FIG. 4, the time transition of storage voltage VB of power storage unit 30 from the time when power generation by self-power generation unit 20 is performed until the rewriting of the display of electronic display medium 200 is completed. The operation of the control unit 40 and the display drive unit 60 and the time transition of ON (operation) -OFF (stop) of the operation of the booster circuit 61 will be described.

(Charging period 1)
In FIG. 4A, first, the time at which the self power generation unit 20 starts power generation is assumed to be time T0.
The storage voltage VB of the storage unit 30 rises to a rewritable voltage (for example, 3.3 V) which is a voltage necessary for rewriting the electronic display medium 200 after a time of about 1 μsec to about 1 second.

  When the storage voltage VB reaches the control unit operating voltage (for example, 1.7 V) (time T1), the control unit 40 and the display drive unit 60 can operate normally. At that time, the reset unit 70 outputs a reset release signal to the control unit 40, thereby activating the control unit 40 in FIG. 4 (b). The control unit 40 having started the operation activates the display drive unit 60 as shown in FIG. 4 (c).

  A period from time T0 to time T1 is about 100 to 200 ms, but in the present embodiment, it is 200 ms. The period from T1 to time T2 when the storage voltage VB rises to the rewriteable voltage takes about 400 ms. Therefore, the length of the charging period 1 is about 600 ms.

(Rewriting period 1)
At time T2, the control unit 40 transmits a command to start the operation of the booster circuit 61, turns on the booster circuit 61, and the rise time Tα (approximately 50 milliseconds to 200 milliseconds) until the boosted voltage is stabilized. After waiting, rewriting of the electronic display medium 200 is started. Here, a period from time T2 to time T3 at which rewriting is completed is defined as rewriting period 1.

  After the boosted voltage of the booster circuit 61 shown in FIG. 4D is stabilized, the display drive unit 60 receives a drive signal application command from the control unit 40, applies a drive signal to the electronic display medium 200, and the electronic display medium 200. Rewrite the displayed image and display a new image.

  Since a current of several tens of microamperes to several hundreds of microamperes flows along with the driving of the electronic display medium 200 by the display drive unit 60, the storage voltage VB of the storage unit 30 gradually decreases in FIG. . Rewriting of the electronic display medium 200 is completed at T3 when about 400 ms has elapsed from T2.

  When the rewriting is completed, the booster circuit 61 of FIG. 4D stops its operation. On the other hand, the other parts of the display drive unit 60 do not stop but continue to operate. Thereby, the drive device 100 can significantly suppress the power consumption while maintaining the function of the display drive unit 60.

  Therefore, when the booster circuit 61 is stopped, the storage voltage VB is held without being reduced. Thus, while the necessary operation is being performed, it is possible to wait for the stored voltage VB to rise again until the self power generation unit 20 starts power generation.

(Charging period 2)
After the elapse of the rewrite period 1 (time T3), the self power generation unit 20 is operated again, and the self power generation unit 20 generates power again, and starts accumulating power in the storage unit 30. As shown in FIG. 4A, the storage voltage VB at time T3 is larger than 1.7 V, which is the storage voltage VB at T1. Therefore, the period until the stored voltage VB reaches the rewriteable voltage again (time T4) is shorter than that in the charging period 1 and may be about 200 ms.

(Rewriting period 2)
The control unit 40 writes the new image into the new image buffer of the image buffer 62 of the display drive unit 60.

Then, when the storage voltage VB reaches the rewriteable voltage again at time T4, the booster circuit 61 is turned ON, and the display drive unit 60 applies a drive signal to the electronic display medium 200 after the rise time Tα has elapsed. The display image of the electronic display medium 200 is rewritten. At this time, the time required for rewriting is about 400 ms as well, because the conditions are the same as in the rewriting period 1.

  Hereinafter, even after charge period 3 from time T5 to time T6, storage voltage VB after the end of the rewrite period is larger than 1.7 V which is storage voltage VB at T1, similarly to charge period 2, The period until the possible voltage is reached may be as short as the charging period 2.

  As described above, when the rewriting of the electronic display medium 200 is completed, the display drive unit 60 stops only the booster circuit 61, and the other parts continue to operate without stopping. By doing this, since the current consumption of the display drive unit 60 becomes very small, it is possible to efficiently charge in a short time without using unnecessary current.

  In addition, it is possible to omit the charge initialization processing at the time of activating the display drive unit 60 from the stop state and the image transfer from the non-volatile memory 50. This has the effect of shortening the time required for the stored voltage VB to rise to the rewriteable voltage in the second and subsequent charging periods.

  In addition, assuming that the booster circuit 61 is not stopped even after the rewriting is completed, the consumption current remains large, so when it takes a long time before the self-generating unit 20 starts power generation, the storage voltage VB continues to decrease. It is assumed that the voltage required to operate the control unit 40 and the display drive unit 60 is lower than that.

  Then, even if the trigger output unit 10 is operated next, the control unit 40 and the display drive unit 60 need to be activated again to perform the initial setting process, so the time required to rewrite the electronic display medium 200 is long. It takes it.

  In order to solve such a problem, as in the present embodiment, it is very effective to stop the booster circuit 61 after the rewriting is completed, to suppress the consumption of power and wait for the operation to the next trigger output unit 10 It is.

  The present embodiment is also very effective when it is desired to continuously rewrite the display of the electronic display medium 200. By stopping the booster circuit 61 and shortening the charging period, it is possible to smoothly carry out a plurality of consecutive rewrites.

(Modification 1)
As a first modification of this embodiment, a plurality of display areas are provided on the electronic display medium 200. For example, in the case where the electronic display medium 200 has a large display screen or has a plurality of electronic display media 200, it is not possible to rewrite all of the display area at once with limited power derived from self-power generation. Therefore, a plurality of display areas obtained by dividing the display area of the electronic display medium 200 into several parts are provided, and are sequentially rewritten in order.

  In this case, it is preferable that the period required to rewrite the entire display area be as short as possible, and thus the plurality of display areas of the electronic display medium 200 are continuously rewritten by the above-described means. That is, by stopping the booster circuit 61 and shortening the charging period, the continuous rewriting of the display area is smoothly performed. Thus, the entire display area can be quickly rewritten.

Further, in the first modification, the display area of the electronic display medium 200 having a large screen is divided into display areas of a plurality of small screens, and one display is made for a plurality of display areas such as a plurality of electronic display medium 200. It drives by the drive part 60 and rewrites a display.

  Therefore, since the size of the display area that the display drive unit 60 rewrites each time is small, the size of the circuit can be reduced simply by providing the small display drive unit 60 as the display drive unit 60 that rewrites the display.

  Further, in the present embodiment, a display drive is performed using a drive device 100 having a self-power generation unit 20 for a device or a terminal that is often operated continuously, such as a remote control for home appliances such as a television and an air conditioner. The voltage boosting circuit 61 of the unit 60 is stopped to shorten the charging period.

  By doing so, the rewriting of the display of the electronic display medium 200 can be continuously performed according to the continuous operation. Thereby, there is an effect that it is possible to reduce the sense of incongruity felt by the user.

  As described above, since the display device according to the present embodiment stops the booster circuit 61 during the charging period of the storage unit 30, the storage unit 30 is suppressed by suppressing the consumption of power by the booster circuit 61. There is an effect that the charging time for accumulating power can be shortened.

  Further, since the power consumption is suppressed by stopping the booster circuit 61 after the rewriting is completed, the display image can be rewritten continuously, and the target to which the electronic display medium using self power generation can be applied is greatly expanded. There is also an effect that can be done.

Second Embodiment
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6. As in the block diagram of FIG. 5, the drive device 100 differs from the first embodiment in that the drive device 100 includes a voltage measurement unit 80.

(Voltage measurement unit 80)
Control unit 40 transmits a command for measuring storage voltage VB of power storage unit 30 to voltage measurement unit 80 after activation and a predetermined time has elapsed. Voltage measurement unit 80 measures storage voltage VB of the power stored in storage unit 30 and transmits storage voltage VB, which is the measurement result, to control unit 40.

  If the stored voltage VB exceeds the predetermined voltage, the control unit 40 transmits a command to start the operation of the booster circuit 61 to the display drive unit 60, and turns on the booster circuit 61. After the rise time Tα of the booster circuit has elapsed, a drive signal application command instructing application of a drive signal to the electronic display medium 200 is transmitted to the display drive unit 60.

  The predetermined voltage of the storage voltage VB referred to here is a voltage necessary for rewriting the image of the electronic display medium 200, and is, for example, 3.3V.

  As a result of the measurement of the storage voltage VB by the voltage measurement unit 80 as described above, when the voltage does not exceed the predetermined voltage, the control unit 40 does not transmit a command to start the operation of the booster circuit 61 to the display drive unit 60. Also, the drive signal application command is not transmitted.

  Thereafter, after a predetermined time has elapsed, control unit 40 transmits a command to voltage measurement unit 80 to measure storage voltage VB of power storage unit 30 again. The subsequent operations of the control unit 40 and the voltage measurement unit 80 are the same as in the first voltage measurement.

  Thereafter, similarly, voltage measurement is repeated until the storage voltage VB, which is the measurement result, exceeds a predetermined voltage. In the second and subsequent voltage measurement, the predetermined time for measuring the next voltage may be the same length as in the first voltage measurement, or may be shorter than the first time.

(Operation procedure)
An example of drive processing performed by the drive device 100 according to the second embodiment will be described with reference to the flowchart of FIG. Here, differences from the first embodiment will be mainly described.

  The operations from step S1 to step S4 are the same as in the first embodiment. That is, first, by operating the trigger output unit 10 and the self power generation unit 20, the self power generation unit 20 starts power generation, and the power is stored in the power storage unit 30.

  Next, the control unit 40 is activated, and the control unit 40 activates the display drive unit 60. At that time, the control unit 40 transmits a command to stop the operation of the booster circuit 61 to the display drive unit 60, and turns the booster circuit 61 OFF. Subsequently, the control unit 40 inputs new image information instructed by the user pressing the trigger output unit 10 into the image buffer 62 of the display drive unit 60.

(Step S5a)
Control unit 40 measures storage voltage VB of power storage unit 30 using voltage measurement unit 80 after a predetermined time set in advance has passed.

(Step S5c)
When storage voltage VB exceeds a predetermined voltage (for example, 3.3 V) (step S5 b: Yes), control unit 40 transmits a command to start operation of boost circuit 61 to display drive unit 60, The booster circuit 61 is turned on. Further, a drive signal application command to the electronic display medium 200 is transmitted to the display drive unit 60.

  If storage voltage VB does not exceed the predetermined voltage (step S5b: No), control unit 40 returns to step S5a again to measure storage voltage VB.

(Steps S6 to S9)
The operations from step S6 to step S9 are the same as in the first embodiment. That is, the driver circuit 63 of the display drive unit 60 applies a drive signal to the electronic display medium 200 in accordance with the data of the drive signal generated by the arithmetic circuit 64 to rewrite the display.

  According to the second embodiment of the present invention, the voltage measuring unit 80 measures the storage voltage VB, and the storage voltage VB reliably rises to a rewritable voltage which is a voltage necessary for rewriting the electronic display medium 200. After waiting for the display drive unit 60 to perform processing for display rewriting, it can be expected that stable display rewriting can be performed.

  As described above, since the display drive unit 60 causes the display drive unit 60 to perform the rewrite process after the stored voltage VB rises to the rewriteable voltage, the amount of power generation by the self-power generation unit 20 is not always constant. , Very effective.

Third Embodiment
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. 7 and 8. According to the configuration of the device of the third embodiment, as shown in FIG. 7, in order to generate a drive signal, the display drive unit 160 boosts the voltage supplied from the storage unit 30 at a predetermined boosting frequency. The second embodiment differs from the first embodiment in that the booster circuit 161 and the booster circuit control register 165 that switches the booster frequency of the booster circuit 161 to a high frequency and a low frequency are included.

(Display drive unit 160)
The display drive unit 160 includes a booster circuit 161 and a booster circuit control register 165, an image buffer 162 for storing new image information to be displayed and current image information, an arithmetic circuit 164 for determining a drive waveform to be output to each pixel, and a drive. And a driver circuit 163 for selecting a waveform, and outputs a predetermined drive signal to the electronic display medium 200.

  The display drive unit 160 applies a drive signal to the electronic display medium 200 to rewrite the current image displayed on the electronic display medium 200 into a new image.

  The booster circuit control register 165 controls the boosting frequency of the booster circuit 161 of the display drive unit 160 to a low frequency during the charge period of the storage unit 30, and during the rewrite period of the electronic display medium 200, the display drive unit 160. The step-up frequency of the step-up circuit 161 is controlled to a high frequency. When the boost frequency is low, the boost capability decreases, the rise time Tα to reach a stable voltage increases, and the maximum current during the rewrite period decreases, so the boosted voltage decreases during the rewrite operation. In some cases.

  Control for switching the boost frequency to the low frequency and the high frequency is performed by the control unit 40 transmitting a command to switch the boost frequency to the boost circuit control register 165. In the charging period for charging storage unit 30, control unit 40 transmits a command to control the boosting frequency to a low frequency to boosting circuit control register 165, and in the rewriting period for rewriting electronic display medium 200, control unit 40. Transmits a command for controlling the boosting frequency to a high frequency to the boosting circuit control register 165.

  Subsequently, with reference to the timing chart of FIG. 8, the time transition of storage voltage VB of power storage unit 30 from the time when power generation by self power generation unit 20 is performed to the time rewriting of the display of electronic display medium 200 is completed. The operation of the control unit 40 and the display drive unit 160 and the time transition of ON (operation) -OFF (stop) of the operation of the booster circuit 161 will be described.

(Charging period 1)
In FIG. 8A, when self-power generation unit 20 starts power generation at time 0, storage voltage VB can be rewritten, which is a voltage necessary for rewriting electronic display medium 200, after a time of about 1 μsec to 1 sec. It rises to the voltage. When the storage voltage VB reaches the control unit operating voltage (for example, 1.7 V), the control unit 40 and the display drive unit 60 can operate normally. At that time, the reset unit 70 outputs a reset release signal to the control unit 40, thereby activating the control unit 40 as shown in FIG. 8 (b).

  As shown in FIG. 8C, the control unit 40 that has started the operation activates the display drive unit 160 and initializes the booster circuit control register 165. Thereafter, an instruction to set the boosting frequency of the boosting circuit 161 to a low frequency is transmitted to the boosting circuit control register 165 to set the boosting frequency of the boosting circuit 161 to a low frequency and start the boosting operation.

(Rewriting period 1)
At time T2, control unit 40 transmits to boost circuit control register 165 a command for setting the boost frequency of boost circuit 161 to a high frequency, thereby setting the boost frequency to a high frequency and a rise time Tα until the boosted voltage is stabilized. Wait for a while.

  Then, the control unit 40 transmits a drive signal application command instructing the display drive unit 160 to apply a drive signal to the electronic display medium 200. Thus, the image displayed on the electronic display medium 200 is rewritten to display a new image.

  Even after the end of the rewriting period 1, the charging period and the rewriting period are repeated.

  In the present embodiment, since the booster circuit 161 is not completely stopped and operates at a low frequency boosted frequency, compared to the first embodiment, the time for the stored voltage VB to rise to the rewriteable voltage becomes longer.

  On the other hand, during the charging period, the booster circuit 161 continues to operate at a low frequency booster frequency, and the boosted voltage holds approximately 15 V. Therefore, when the booster circuit is changed to a high frequency, the booster circuit 161 is (About 10 milliseconds to about 50 milliseconds) is shortened. As a result, the length of the rewriting period becomes shorter by about 50 m to 150 ms compared to the first embodiment.

  Thus, when it is desired to continuously rewrite the display of the electronic display medium 200, the time from when the trigger output unit 10 is operated to when the rewriting of the electronic display medium 200 actually starts can be shortened. It is very effective.

  In addition, when the driving current of the electronic display medium 200 is large, if the boosting circuit is always operated, the boosting period of the boosting circuit 161 becomes long in order to boost the voltage while securing the driving current. The use of the third embodiment has a particularly great effect of shortening the start-up period and shortening the rewriting period.

  The drive device of the present invention has been described above. The voltage for driving the electronic display medium 200 of the present invention is not limited to -15 V or +15 V in the above-described embodiment, and may be another voltage depending on the driver IC or electronic display medium used.

  Further, in the above-described embodiment, the microcapsule type electronic paper is used as the electronic display medium, but the display medium is particularly limited as long as it is a display medium having a memory property capable of holding a display image even when power is not supplied. For example, a microcup-type electronic paper or a twist ball-type electronic paper may be used instead, and a dot matrix-type electronic paper may be used or a segment-type electronic paper may be used.

  However, by using a segment-type electronic paper, a circuit configuration and a driving method are simplified, and power required for rewriting can be reduced, so that a display device with low power consumption can be realized. In particular, when power is obtained by self-generation as in the present invention, large power can not always be obtained, and display can be stably rewritten even with small power by using a display device with low power consumption. It is more preferable because it is possible to preferably suppress erroneous display.

  Further, the display color of the electronic paper is not limited to white and black. For example, three colors such as white and red, white and blue, white and green, and white and black and red, and white and black and yellow may be considered.

  In the embodiment described above, the case where the operation unit is one push button has been described, but a plurality of push buttons may be provided to display which push button has been pressed how many times. . In this case, a plurality of self power generation units may be provided for each push button, or one self power generation unit may be configured to be able to operate with a plurality of push buttons.

  Further, the drive device 100 further includes a communication device, and not only the electronic display medium 200 is driven by the power generated by self-generation but also the communication device is driven, and information corresponding to the display state of the electronic display medium 200 is displayed. , May be sent to another device comprising the receiving device.

  Note that part or all of the functions described above may be realized as an integrated circuit such as LSI (Large Scale Integration). Each function mentioned above may be processor-ized separately, and part or all may be integrated and processor-ized.

  Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. In the case where an integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology, integrated circuits based on such technology may also be used.

10: trigger output unit 20: self power generation unit 30: storage unit 40: control unit 41: storage unit 50: non-volatile memory 60, 160: display drive unit 61, 161: Booster circuit 62, 162: Image buffer 63, 163: Driver circuit 64, 164: Arithmetic circuit 165: Booster circuit control register 70: Reset unit 80: Voltage measurement Section 100 Drive device 200 Electronic display medium 210 Upper electrode 220 Lower electrode 230 Microcapsule 240 White particles 250 Black particles 260 Transparent solvent A: Observation direction T0: Power generation start time T1: Control unit operation start time T2: Boosting circuit start-up start time T3: Second power generation start time T4: Second, Boost circuit start time 5 ... of the third power generation start time T6 ... third booster circuit rise start time T7 ... rewrite processing end time T [alpha ... boosting circuit start-up period

Claims (6)

A driving device for driving an electronic display medium,
A control unit that controls the drive device;
A self-generation unit that generates electricity,
A storage unit that stores the power generated by the self-generation unit and supplies the power to the drive device;
A display drive unit for applying a drive signal to the electronic display medium;
Equipped with
The display drive unit includes a booster circuit that boosts a voltage supplied from the storage unit to generate the drive signal;
The control unit is configured to stop the booster circuit during a charge period for storing power in the storage unit, and operate the booster circuit during a rewrite period for applying the drive signal to the electronic display medium. Drive device. A driving device for driving an electronic display medium,
A control unit that controls the drive device;
A self-generation unit that generates electricity,
A storage unit that stores the power generated by the self-generation unit and supplies the power to the drive device;
A display drive unit for applying a drive signal to the electronic display medium;
Equipped with
The display drive unit includes a switching type booster circuit that boosts the voltage supplied from the storage unit at a predetermined boosting frequency to generate the drive signal.
The control unit sets the boosting frequency of the boosting circuit to a low frequency during a charging period in which power is stored in the storage unit, and the boosting frequency during a rewriting period in which the drive signal is applied to the electronic display medium. A driving device characterized by having a high frequency. A driving device according to claim 1 or 2, wherein
A voltage measurement unit that measures a storage voltage of the power stored in the storage unit;
The voltage measurement unit transmits the stored voltage to the control unit.
The control unit starts the rewrite period when the stored voltage reaches a predetermined voltage. A method of driving an electronic display medium comprising a driving device, comprising:
A control unit that controls the drive device, a self-power generation unit that generates power, and a storage unit that stores the power generated by the self-power generation unit and supplies the power to the drive device; A display drive unit for applying a drive signal to an electronic display medium, the display drive unit having a booster circuit for boosting a voltage supplied from the storage unit in order to generate the drive signal;
Stopping the boosting circuit during a charging period in which power is stored in the storage unit;
Operating the booster circuit during a rewriting period in which the drive signal is applied to the electronic display medium;
A method of driving an electronic display medium, comprising:   A display device comprising the drive device according to any one of claims 1 to 3.   The display device according to claim 5, wherein the electronic display medium has a plurality of display areas.

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