JP2012189421A - Electronic timepiece and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic timepiece which performs the time display different from the ordinary time display even in a display mode in which power consumption is suppressed, and does not lose a function as the timepiece.SOLUTION: The electronic timepiece includes: power supply voltage detection means 31 which detects a voltage of a power supply; a time counting means 13 which counts the time; a display means 10 having memory properties; and a control means 14 which controls display of the display means. The control means performs switching control of the display mode of the display means in which a first mode for performing the ordinary display and a second mode having longer update interval of the display than the first mode are alternately switched. In the first mode, the display means is made to display the time, and the switching control from the first mode to the second mode is performed when a voltage value detected by the power supply voltage detection means is less than a predetermined value in the first mode. In the second mode, the display means is made to display representing at least the hour value of the time.

Description

  The present invention relates to an electronic timepiece, a method for controlling an electronic timepiece, and the like.

  In recent years, a display panel having a memory property that can hold an image even when the power is turned off has been developed and used in an electronic timepiece or the like. As a display panel having a memory property, an EPD (Electro Phoretic Display), that is, an electrophoretic display device, a memory-type liquid crystal display device, and the like are known.

  When displaying the time on the memory-type display panel, for example, even when the time cannot be updated due to insufficient battery power, the time is continuously displayed due to the holdability of the display panel. Therefore, the user may misunderstand that the incorrect time display that has not been updated is the current time.

  The invention of Patent Document 1 avoids this problem by hiding the time display when the remaining battery level is reduced to some extent.

Japanese Patent Laid-Open No. 2007-40888

  However, particularly in the application of an electronic timepiece, the user looks at the display panel when he wants to know the time. At that time, if the time display is not displayed, the time display function as a clock is lost. Further, in the invention of Patent Document 1, the time is not displayed unless the power supply voltage is increased, and the user's request to know the time immediately cannot be met.

  Here, it is possible to always display the time. However, a battery-driven electronic device such as an electronic timepiece is required to have, for example, a power saving mode (power save mode) or the like in order to make the battery last longer. For example, when an electrophoretic display device is used, it is required to perform display control according to the usage environment such as the remaining battery level, the amount of power generated by the solar generator, and the temperature in order to maintain display quality. Therefore, it is not a realistic solution to always display the time.

  The present invention has been made in view of such problems. According to some embodiments of the present invention, an electronic timepiece that performs time display different from normal time display even in a display mode that suppresses power consumption and does not lose its function as a timepiece is provided.

(1) The present invention includes power supply voltage detection means for detecting the voltage of the power supply, time measurement means for measuring time, memory display means, and control means for controlling display of the display means, The control means performs switching control to switch the display mode of the display means between a first mode for performing normal display and a second mode having a display update interval longer than the first mode, and performs the first mode. When the time is displayed on the display means and the switching control from the first mode to the second mode is performed, the voltage value detected by the power supply voltage detection means in the first mode is less than a predetermined value. In the second mode, the display means displays at least the time digits of the time.

(2) In this electronic timepiece, the control means may display the reason why the normal display is not performed in the second mode.

  According to the electronic timepieces of these inventions, when normal time display (hereinafter referred to as normal display) is not performed, an approximate time is displayed to the user by displaying at least time digits while suppressing power consumption. Can be informed. Therefore, by providing display modes other than the normal display, it is possible to meet the demand of the user who wants to know the time immediately while realizing low power consumption.

  The display mode of the electronic timepiece of the present invention is normally the first mode. Here, the normal display in the first mode displays an accurate time of at least one minute. The normal display may include not only the display of hours and minutes (or hours, minutes and seconds) but also displays of dates, characters, figures, symbols, backgrounds, and the like.

  The display update in the normal display is performed at least every minute when displaying the hour and minute, and at least every second when displaying the hour, minute, and second.

  In the electronic timepiece of the invention, in the display mode (second mode) in which display other than normal display is performed, the time for applying the voltage based on the drive pulse signal is set by making the display update interval longer than in the first mode. Can be reduced and power consumption can be reduced.

  At this time, since the display in the second mode includes at least the hour digit of the time, the user can grasp at least what time it is. Therefore, even when the display mode is the second mode, the clock function is not lost.

  Switching from the first mode to the second mode is performed when the power supply voltage detected by the power supply voltage detection means is less than a predetermined value. For example, since the power consumption can be appropriately suppressed when the remaining amount of the battery is low, the battery can be extended.

  The display in the second mode may include a reason why the normal display is not performed. Thereby, the user can take appropriate measures such as battery replacement or charging.

  Note that the time information is given from a time measuring means such as a time counter. The time may be the current time, or may be a local time designated by the user in the case of world time or the like.

(3) In this electronic timepiece, the control unit may update the display of the display unit based on a change in the hour digit of the time in the second mode.

(4) In the electronic timepiece, the control means causes the display means to display an analog timepiece in the second mode, and an area corresponding to the time digit of the time in the analog timepiece is different from other areas. It may be displayed in color.

(5) In this electronic timepiece, the control means may update the display of the display means based on a change of the tenth digit of the time in the second mode.

(6) In this electronic timepiece, the control means may update the display of the display means based on the time changing to 0 minutes or 30 minutes in the second mode.

(7) The electronic timepiece includes an input unit that receives an instruction from the outside, and the control unit sets an update interval of the display of the display unit in the second mode based on the instruction received by the input unit. It may be determined.

  According to these inventions, when the display mode is the second mode, the display is updated at a predetermined update interval longer than that in the first mode. Therefore, the approximate time is notified to the user while suppressing power consumption.

  For example, the display update interval in the second mode is 1 hour, and the update may be performed based on the change of the time digit of the time from the time measuring means. The user can know the time (hours) in units of one hour, and can greatly reduce power consumption.

  At this time, in the second mode, a visually comprehensible display may be performed. For example, an approximate time may be notified to the user by displaying an analog clock and changing the display of the portion corresponding to the hour digits in the analog clock. The shape of the analog clock may be a circle or an ellipse, and numbers may or may not be displayed.

  The area corresponding to the hour digit in the analog timepiece means an area in a certain range including the hour hand when displaying with the analog timepiece. For example, a circular analog timepiece may be a region that is included as long as the hour hand is present by dividing the area of the circle into 12 equal parts by radiating a line radially from the center.

  Further, the display update interval in the second mode is 10 minutes, and the update may be performed based on the change of the 10-minute digit of the time from the time measuring means. Although the power consumption increases as compared with the case where the update interval is 1 hour, the user can know more accurate time in units of 10 minutes.

  Here, the update interval is not limited to the one corresponding to the hour / minute digits of the time. For example, the display update interval in the second mode is 30 minutes, and the update may be performed based on the fact that the minute digits of the time from the time measuring means become 0 minutes or 30 minutes.

  Further, this update interval may be specified by a user or the like by an external input means. At this time, the accuracy of time display in the second mode can be set in consideration of a balance with power consumption.

  The instruction from the outside is not limited to an instruction from the user of the electronic timepiece, but may be an instruction from another device.

(8) In this electronic timepiece, the control means performs the switching control from the second mode to the first mode, and the voltage value detected by the power supply voltage detection means in the second mode is a predetermined value or more. It is possible to go if it is.

  According to the present invention, when the electronic timepiece is operating in the second mode, the electronic timepiece may return to the first mode when the voltage value detected by the power supply voltage detection means is equal to or greater than a predetermined value. It is possible to control power consumption appropriately according to the remaining battery level.

(9) The present invention is a method for controlling an electronic timepiece including a power supply voltage detecting means for detecting a voltage of a power supply, a time measuring means for measuring time, and a memory display means. The display mode is a first mode for performing normal display, and the time is displayed on the display means, and the voltage value detected by the power supply voltage detection means in the first mode is less than a predetermined value. In some cases, the display means is switched to the second mode, in which the display update interval of the display means is longer than that of the first mode, and in the second mode, at least the time is displayed on the display means. And a third step of displaying the time digits.

  According to the present invention, when the normal time display is not performed, it is possible to realize the control of the electronic timepiece that informs the user of the approximate time by displaying at least the hour digit while suppressing power consumption. . Therefore, by providing display modes other than the normal display, it is possible to meet the demand of the user who wants to know the time immediately while realizing low power consumption.

The figure which shows the example of a display of the electronic timepiece in 1st Embodiment. FIG. 5 is a state transition diagram showing display mode switching in the first embodiment. 1 is a block diagram of an electronic timepiece according to a first embodiment. The block diagram of EPD in 1st Embodiment. The figure which shows the structural example of the pixel of the display part in 1st Embodiment. FIG. 6A illustrates a configuration example of an electrophoretic element. 6B to 6C are explanatory diagrams of the operation of the electrophoretic element. The flowchart of the control in 1st Embodiment. FIGS. 8A to 8B are flowcharts of the subroutine of FIG. FIG. 9A to FIG. 9C are display examples in the first embodiment. FIG. 10A to FIG. 10C are other display examples in the first embodiment. The block diagram of the electronic timepiece in 2nd Embodiment. The flowchart of control in 2nd Embodiment. The figure which shows the example of a display of the electronic timepiece in 3rd Embodiment. The block diagram of the electronic timepiece in 3rd Embodiment. The flowchart of the control in 3rd Embodiment. FIGS. 16A to 16B are diagrams showing display examples of the electronic timepiece according to the fourth embodiment. The block diagram of the electronic timepiece in 4th Embodiment. The flowchart of control in 4th Embodiment. The figure of the display of the electronic timepiece of a comparative example.

1. First Embodiment A first embodiment of the present invention will be described with reference to FIGS. Here, first, a problem in display of the electronic timepiece of the comparative example will be described with reference to FIG. 19, and then the electronic timepiece of the present embodiment will be described.

1.1. Problem of Display of Electronic Timepiece of Comparative Example FIG. 19 is a front view of the electronic timepiece 100 of the comparative example. The electronic timepiece 100 has a display unit 103 having a memory property. For example, a power save mode (right figure) is provided, and in this mode, low power consumption is realized by not updating the display.

  Here, in the electronic timepiece 100 of the comparative example, the time display is deleted when shifting to the power save mode (right figure). If the time display is not erased, the time display remains in the power save mode due to the memory property of the display unit 103. This is because the time display (14:18 in FIG. 19) when the user is not updated is mistaken as the current time.

  By displaying the POWER SAVE character as shown in FIG. 19, the user can recognize that it is not a normal display. However, it is inconvenient because the time cannot be known immediately. In the electronic timepiece 100 of the comparative example, it is necessary to know the time by, for example, performing an operation such as pressing an operation button and causing the electronic timepiece 100 to perform normal display (left figure).

  At this time, the user cannot even know the approximate time, and the function as a clock is lost. In the electronic timepiece of the present embodiment below, such a problem does not occur in a display mode that suppresses power consumption.

1.2. Display Example of Electronic Timepiece of this Embodiment FIG. 1 is a front view of an electronic timepiece 1 of this embodiment. The electronic timepiece 1 of the present embodiment has a first mode (ST1) and a second mode (ST2) as display modes.

  In FIG. 1, the left figure is a display example of the electronic timepiece 1 in the first mode, and the right figure is a display example of the electronic timepiece 1 in the second mode. Note that TC1 and TC3 represent transitions of the display mode, which are a transition from the first mode to the second mode and a transition from the second mode to the first mode, respectively.

  The electronic timepiece 1 includes a timepiece case 2 and a pair of bands 4 connected to the timepiece case 2. On the front face of the watch case 2, an EPD (electrophoretic display device) display unit 3 and operation buttons 6 and 7 are provided. These operation buttons are used as input means for setting parameters relating to the display mode of the display unit 3, for example. In FIG. 1, the electronic timepiece 1 is a wristwatch, but may be a table clock, a wall clock, or the like.

  The display on the display unit 3 is switched according to the display mode. The display mode of the electronic timepiece 1 is normally the first mode (ST1). The first mode performs a normal display, that is, a display including an accurate time display up to at least one minute digit. The normal display may include not only the hour and minute display as shown on the left side of FIG. 1 but also the display of the second, date, character, figure, symbol, background, and the like.

  In the example of FIG. 1, when the display mode of the electronic timepiece 1 is the first mode, the display on the display unit 3 is updated at least every 1 minute to indicate the current time to the user.

  When the power consumption needs to be suppressed, the display mode of the electronic timepiece 1 is switched to the second mode (TC1). In the second mode (ST2), a time display different from the normal display is performed.

  When the display mode of the electronic timepiece 1 is the second mode, the display unit 3 has a longer update interval than the normal display. Therefore, it is possible to reduce the time for applying the voltage based on the drive pulse signal and suppress power consumption. That is, the electronic timepiece 1 can realize a kind of power saving mode by setting the display mode to the second mode.

  In the example of FIG. 1, when the display mode of the electronic timepiece 1 is the first mode, the display update interval of the display unit 3 is 1 minute. When the display mode of the electronic timepiece 1 is the second mode, the display update interval of the display unit 3 is 1 hour, so that power consumption can be significantly reduced.

  Here, in the second mode of the example of FIG. 1, the display update interval of the display unit 3 is 1 hour, and therefore, the minute digit display cannot be updated correctly. In order to prevent the user from erroneously recognizing the minute digits that are not updated as the current time, the minute digits are displayed other than numbers ("xx") as shown in the right side of FIG. .

  When the normal time display (ST1) is not performed, the electronic timepiece 1 of the present embodiment performs a display representing at least a time digit while suppressing power consumption (ST2). This display can inform the user of the approximate time (in the example of FIG. Therefore, it is possible to meet the demand of the user who wants to know the time immediately while realizing low power consumption.

  When there is no need to reduce power consumption, the display mode of the electronic timepiece 1 returns to the first mode (TC3). Then, normal display is performed.

1.3. Transition of Display Mode FIG. 2 is a state transition diagram showing display mode switching in the present embodiment. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  As described above, the display mode of the electronic timepiece according to the present embodiment is the first mode in which normal display is performed in a normal case (ST1). However, when it is necessary to reduce power consumption, the display mode is switched to the second mode (TC1).

  In the second mode, a time display different from the normal display is performed (ST2). In the second mode, the display is updated at a time interval (for example, 1 hour) longer than the normal display (TC2). When it is no longer necessary to reduce power consumption, the display mode returns to the first mode and normal display is performed (TC3).

  In the normal display in the first mode, the display is updated at least every 1 minute to indicate the current time to the user, but the transition conditions are not shown in FIG.

  Here, the electronic timepiece of the present embodiment has a power save mode in order to make the battery last longer. In the case of the power save mode, the display mode of the electronic timepiece 1 is the second mode for suppressing power consumption.

  In the present embodiment, as will be described later, the electronic timepiece includes a motion sensor. When the electronic timepiece does not sense the user's movement and determines that the timepiece is not being used, the power save mode is set. In the power saving mode, when the movement is detected and it is determined that the timepiece is being used, the mode returns to the normal operation mode. The display mode is also the first mode, and normal display is performed.

  Therefore, in the present embodiment, the transition condition (TC1) from the first mode to the second mode is that the user's movement is not sensed, and the transition condition (TC2) from the second mode to the first mode is: It is to sense the movement of the user. The transition condition (TC1) may be that the state in which the user's movement is not detected continues for a certain period of time, for example, using a timer, or the transition condition (TC1) that the user's movement is detected for a certain period of time or more. TC2) may be used.

  Here, as described above, in the second mode, the display is updated only at a time interval (for example, 1 hour) longer than the normal display. However, the electronic timepiece of this embodiment uses a display unit of an EPD (electrophoretic display device) having a memory property, and a time display different from the normal display is held for a long time.

  Hereinafter, a configuration block diagram of the electronic timepiece of the present embodiment including the EPD will be shown, and an EPD driving method and the like will be described.

1.4. FIG. 3 is a block diagram of the electronic timepiece 1 according to this embodiment. The switching of the display mode can be realized by the configuration of FIG. 3, for example.

  As shown in FIG. 3, the electronic timepiece 1 includes an oscillation circuit 11, a frequency dividing circuit 12, a time counter 13, a display control circuit 14, an EPD 10, switches 15 and 16, a time correction circuit 17, a timer 22, a motion sensor 43, a motion A detection circuit 44 is included. Although illustration of the power source is omitted in FIG. 3, the electronic timepiece 1 may include a primary battery, or may include a power generation device and a secondary battery.

  The oscillation circuit 11 generates a reference oscillation signal by causing a reference oscillation source such as a crystal resonator to oscillate at a high frequency.

  The frequency dividing circuit 12 divides the reference oscillation signal generated by the oscillation circuit 11 to generate a predetermined reference signal (for example, a signal of 1 Hz).

  The time counter 13 counts the reference signal generated by the frequency dividing circuit 12 and measures the current time, for example. The time counter 13 functions as a time measuring means of the electronic timepiece 1. The time counter 13 outputs, for example, a time signal indicating the current time to the display control circuit 14.

  The switches 15 and 16 are turned on by pressing the operation buttons 6 and 7 (see FIG. 1) which are input means from the outside. The switches 15 and 16 are input detection means for detecting the input of the operation buttons 6 and 7. The switches 15 and 16 output signals corresponding to the detected input of the operation buttons 6 and 7 to the time adjustment circuit 17 and the display control circuit 14.

  The time adjustment circuit 17 generates a time adjustment signal based on the signals from the switches 15 and 16 and outputs it to the time counter 13. The time counter 13 corrects the time signal according to the time correction signal.

  The motion sensor 43 detects the motion of the user and outputs a signal corresponding to the motion to the motion detection circuit 44. The motion detection circuit 44 determines whether or not the electronic timepiece 1 is used based on a signal from the sensor 43. Then, a signal for distinguishing whether the electronic timepiece 1 is used or not is input to the display control circuit 14 and the timer 22.

  If the electronic timepiece 1 is a wristwatch, the motion sensor 43 is an acceleration sensor, for example, and may detect the movement of the user's arm. If the electronic timepiece 1 is a table clock, the motion sensor 43 is a sensor that senses infrared rays, for example, and may detect whether there is a person around the electronic timepiece 1.

  For example, if the electronic timepiece 1 is a wristwatch, the movement detection circuit 44 can determine that the electronic timepiece is in use if the user's arm moves. If the electronic timepiece 1 is a table clock, it can be determined that the electronic timepiece is in use if there are people around it.

  The timer 22 receives the reference signal from the frequency dividing circuit 12. Then, the motion detection circuit 44 measures the non-use time when it is determined that the electronic timepiece 1 is not used. If the non-use time continues for a predetermined time or longer, a signal indicating that is output to the display control circuit 14.

  The timer 22 may measure the duration of the signal when the motion detection circuit 44 outputs a signal indicating that the electronic timepiece 1 is no longer in use. If the electronic timepiece 1 has been used for a predetermined time or longer, a signal indicating this may be output to the display control circuit 14.

  The display control circuit 14 controls the content displayed on the EPD 10 and the display mode by the control signal 18. The display control circuit 14 functions as a control unit that controls display of the electronic timepiece 1.

  The display control circuit 14 normally sets the display mode to the first mode. Then, based on the time signal from the time counter 13, the EPD 10 displays the time.

  However, when it is necessary to reduce power consumption, the display mode is set to the second mode. In the second mode, the EPD 10 is caused to display a time different from the normal display.

  In the present embodiment, the case where the power consumption needs to be suppressed is that the motion detection circuit 44 determines that the electronic timepiece 1 is not used, and the determination of the non-use state continues for a predetermined time or more. is there. That is, specifically, based on the change in the signal from the timer 22, the display control circuit 14 sets the display mode to the second mode.

  The display control circuit 14 can immediately set the display mode to the second mode when the motion detection circuit 44 determines that the electronic timepiece 1 is not being used. However, in this case, there is a possibility that normal display is not performed due to erroneous detection. Therefore, it is preferable to set the display mode to the second mode based on the change in the signal from the timer 22.

  When it is no longer necessary to reduce power consumption in the second mode, the display control circuit 14 returns the display mode to the first mode.

  In the present embodiment, the case where it is not necessary to suppress the power consumption is that the motion detection circuit 44 determines that the electronic timepiece 1 has started to be used. That is, specifically, based on the change in the signal from the motion detection circuit 44, the display control circuit 14 returns the display mode to the first mode.

  The display control circuit 14 can also return to the first mode when the motion detection circuit 44 continuously outputs a signal indicating that the electronic timepiece 1 has started to be used for a predetermined time or longer. However, in this case, a state in which normal display is not performed continues for a while although the user wants to use the electronic timepiece. Therefore, it is preferable to immediately return to the first mode based on the change in the signal from the motion detection circuit 44.

  The electronic timepiece 1 of this embodiment includes an EPD 10 as a display device. As will be described later, in the EPD 10, the electrophoretic particles do not move when there is no potential difference between the electrodes. Therefore, it has a memory property. The EPD 10 functions as a memory display unit of the electronic timepiece 1. The display unit of the EPD 10 corresponds to the display unit 3 in FIG.

  In addition, it is not necessary to apply a voltage based on the drive pulse signal to give a potential difference between the common electrode and the pixel electrode except when updating the display. Therefore, power consumption can be suppressed in the second mode in which the update interval is longer than that of the normal display.

1.5. EPD
1.5.1. Configuration of EPD FIG. 4 is a diagram showing a configuration of an active matrix type EPD (electrophoretic display device) of the present embodiment. The driving method may be a segment method, or a memory type liquid crystal display device may be used instead of the EPD.

  The EPD 10 includes an EPD control unit 60, a storage unit 160, and a display unit 3. The EPD control unit 60 controls the display unit 3 and includes a scanning line drive circuit 61, a data line drive circuit 62, a controller 63, and a common power supply modulation circuit 64. In the present embodiment, the EPD control unit 60 is described as controlling the display unit 3 based on the control signal 18 from the display control circuit 14 (see FIG. 3), but some or all of the functions of the EPD control unit 60 are described. May be included in the display control circuit 14.

  The scanning line driving circuit 61, the data line driving circuit 62, and the common power supply modulation circuit 64 are each connected to the controller 63. The controller 63 comprehensively controls these based on the image signal read from the storage unit 160 and the control signal 18. The controller 63 may include a storage unit 160.

  The storage unit 160 may be an SRAM, a DRAM, or other memory, and stores at least image data (image signal) to be displayed on the display unit 3. In addition, information necessary for control by the controller 63 may be stored in the storage unit 160.

  The display unit 3 is formed with a plurality of scanning lines 66 extending from the scanning line driving circuit 61 and a plurality of data lines 68 extending from the data line driving circuit 62, and a plurality of pixels corresponding to these intersecting positions. 40 is provided.

The scanning line driving circuit 61 is connected to each pixel 40 by _m scanning lines 66 (Y ₁ , Y ₂ ,..., Y _m ). The scanning line driving circuit 61 regulates the ON timing of the driving TFT 48 (see FIG. 5) provided in the pixel 40 by sequentially selecting the scanning lines 66 from the first row to the m-th row under the control of the controller 63. A selection signal is supplied.

The data line driving circuit 62 is connected to each pixel 40 by _n data lines 68 (X ₁ , X ₂ ,..., X _n ). The data line driving circuit 62 supplies an image signal defining 1-bit image data corresponding to each of the pixels 40 to the pixels 40 under the control of the controller 63. In the present embodiment, when defining pixel data “0”, a low-level image signal is supplied to the pixel 40, and when defining image data “1”, a high-level image signal is applied to the pixel 40. 40.

The display unit 3 also includes a low-potential power line 49 (Vss), a high-potential power line 50 (Vdd), a common electrode line 55 (Vcom), and a first pulse signal line 91 (S) extending from the common power modulation circuit 64. ₁ ), a second pulse signal line 92 (S ₂ ) is provided, and each wiring is connected to the pixel 40. The common power supply modulation circuit 64 generates various signals to be supplied to each of the wirings according to the control of the controller 63, and performs electrical connection and disconnection (high impedance, Hi-Z) of these wirings.

1.5.2. Circuit Configuration of Pixel Part FIG. 5 is a circuit configuration diagram of the pixel 40 of FIG. In addition, the same number is attached | subjected to the same wiring as FIG. 4, and description is abbreviate | omitted. Further, the description of the common electrode wiring 55 common to all pixels is omitted.

  The pixel 40 is provided with a driving TFT (Thin Film Transistor) 48, a latch circuit 70, and a switch circuit 80. The pixel 40 has an SRAM (Static Random Access Memory) type configuration in which an image signal is held as a potential by a latch circuit 70.

  The driving TFT 48 is a pixel switching element made of an N-MOS transistor. The gate terminal of the driving TFT 48 is connected to the scanning line 66, the source terminal is connected to the data line 68, and the drain terminal is connected to the data input terminal of the latch circuit 70. The latch circuit 70 includes a transfer inverter 70t and a feedback inverter 70f. A power supply voltage is supplied to the inverters 70t and 70f from the low potential power supply line 49 (Vss) and the high potential power supply line 50 (Vdd).

  The switch circuit 80 includes transmission gates TG1 and TG2, and outputs a signal to the pixel electrode 35 (see FIGS. 6B and 6C) according to the level of the pixel data stored in the latch circuit 70. . Note that Va means a potential (signal) supplied to the pixel electrode of one pixel 40.

Image data "1" in the latch circuit 70 (the image signal of high level) is stored, the transmission gate TG1 is turned on, the switch circuit 80 supplies the signals S ₁ as Va. On the other hand, the image data "0" in the latch circuit 70 (the image signal of a low level) is stored, when the transmission gate TG2 is turned on, the switch circuit 80 supplies the signal S ₂ as Va. With such a circuit configuration, the EPD control unit 60 can control the potential (signal) supplied to the pixel electrode of each pixel 40.

1.5.3. Display Method The EPD 10 of this embodiment is assumed to be a two-particle microcapsule type electrophoresis method. If the dispersion is colorless and transparent, and the electrophoretic particles are white or black, at least two colors can be displayed with two colors of white or black as basic colors. Here, it is assumed that the EPD 10 can display black and white as basic colors.

  FIG. 6A is a diagram illustrating a configuration of the electrophoretic element 132 of the present embodiment. The electrophoretic element 132 is sandwiched between the element substrate 130 and the counter substrate 131 (see FIGS. 6B and 6C). The electrophoretic element 132 is configured by arranging a plurality of microcapsules 120. The microcapsule 120 encloses, for example, a colorless and transparent dispersion, a plurality of white particles (electrophoretic particles) 127, and a plurality of black particles (electrophoretic particles) 126. In the present embodiment, for example, it is assumed that the white particles 127 are negatively charged and the black particles 126 are positively charged.

  FIG. 6B is a partial cross-sectional view of the display unit 3 of the EPD 10. The element substrate 130 and the counter substrate 131 sandwich the electrophoretic element 132 in which the microcapsules 120 are arranged. The display unit 3 includes a drive electrode layer 350 in which a plurality of pixel electrodes 35 are formed on the electrophoretic element 132 side of the element substrate 130. In FIG. 6B, a pixel electrode 35 </ b> A and a pixel electrode 35 </ b> B are shown as the pixel electrode 35. The pixel electrode 35 can supply a potential to each pixel (for example, Va, Vb). Here, a pixel having the pixel electrode 35A is referred to as a pixel 40A, and a pixel having the pixel electrode 35B is referred to as a pixel 40B. The pixel 40A and the pixel 40B are two pixels corresponding to the pixel 40 (see FIGS. 4 and 5).

  On the other hand, the counter substrate 131 is a transparent substrate, and an image is displayed on the counter substrate 131 side in the display unit 3. The display unit 3 includes a common electrode layer 370 in which a common electrode 37 having a planar shape is formed on the electrophoretic element 132 side of the counter substrate 131. The common electrode 37 is a transparent electrode. Unlike the pixel electrode 35, the common electrode 37 is an electrode common to all pixels, and is supplied with the potential Vcom.

  The electrophoretic element 132 is disposed on the electrophoretic display layer 360 provided between the common electrode layer 370 and the drive electrode layer 350, and the electrophoretic display layer 360 serves as a display region. A desired display color can be displayed for each pixel according to the potential difference between the common electrode 37 and the pixel electrode (for example, 35A, 35B).

  In FIG. 6B, the common electrode side potential Vcom is higher than the potential Va of the pixel electrode of the pixel 40A. At this time, the negatively charged white particles 127 are attracted to the common electrode 37 side, and the positively charged black particles 126 are attracted to the pixel electrode 35A side, so that the pixel 40A is visually recognized as displaying white.

  In FIG. 6C, the common electrode side potential Vcom is lower than the potential Va of the pixel electrode of the pixel 40A. At this time, on the contrary, the positively charged black particles 126 are attracted to the common electrode 37 side, and the negatively charged white particles 127 are attracted to the pixel electrode 35A side, so that it is visually recognized that the pixel 40A displays black. Is done. Note that the structure in FIG. 6C is similar to that in FIG. Further, in FIGS. 6B and 6C, Va, Vb, and Vcom are described as fixed potentials. However, in actuality, Va, Vb, and Vcom are voltages based on a driving pulse signal, and potentials are increased with time. Changes.

  In the second mode, the display is updated only at a time interval (for example, 1 hour) longer than the normal display. Therefore, in the second mode, the time for applying the voltage based on the drive pulse signal is shorter than in the first mode, and as a result, the power consumption can be suppressed.

  In addition, when a voltage based on the drive pulse signal is not applied, the electrophoretic particles do not move. Therefore, the same display is maintained until the update is performed.

1.6. Flowchart FIG. 7 is a flowchart of control performed by the display control circuit of the electronic timepiece according to this embodiment.

  The display control circuit checks whether the current display mode is the first mode (S10), and performs different processing depending on the display mode.

  Usually, the display mode of the electronic timepiece is the first mode (S10Y). When the motion of the user is detected by the motion sensor, that is, when the electronic timepiece is used (S12Y), the display unit performs normal display (S30). And it returns to S10 again.

  Even in the first mode (S10Y), when the motion of the user is not detected by the motion sensor, that is, when the electronic timepiece is not used (S12N), the timer is counted up (S14). The unused time is counted by the timer, and when the timer reaches a predetermined value, the display mode is set to the second mode (S16Y, S18).

  In this embodiment, instead of immediately shifting to the second mode when it is determined that the electronic timepiece is not used, the display mode is changed by waiting for a non-use time exceeding a predetermined time by a timer. For this reason, it is possible to prevent the normal display from being erroneously stopped.

  When the display mode is the second mode, the display unit displays time that is not normal display (S20). In the second mode, since the update interval is longer than the normal display, the power consumption can be suppressed, and the approximate time can be communicated to the user. And it returns to S10 again.

  When the display mode of the electronic timepiece is the second mode (S10N), when the motion of the user is detected by the motion sensor, the mode returns to the first mode (S22Y, S24).

  In the present embodiment, a return to the first mode in which normal display is performed is immediately performed, and a user's request for immediately knowing an accurate time is met. At this time, the timer is reset (S26), and after normal display (S30), the process returns to S10 again.

  In the second mode, when the user's motion is not detected by the motion sensor (S10N, S22N), the process returns to S10 again after the time display (S20) which is not the normal display.

  FIGS. 8A and 8B are flowcharts of time display S20 and normal display S30 that are not normally displayed, respectively, and will be described in order.

  The display control circuit of the electronic timepiece receives a time signal from the time counter (see FIG. 3). Then, based on the time signal, it is determined whether or not the time that is the update interval has elapsed. As shown in FIG. 8A, in the second mode, when the time that is the update interval has elapsed (S200Y), the time display is updated and displayed (S202). In other cases (S200N), nothing is done and the display so far is maintained by the memory property of the display unit.

  Here, the update interval is, for example, one hour. At this time, accurate display is performed for the hour digits. In this example, the display control circuit updates and displays the time display only when the time carry is performed based on the time signal.

  The update interval may be a predetermined time such as 1 hour, 30 minutes, 15 minutes, or 10 minutes. However, in this embodiment, it is assumed that the update interval can be set by an external input (for example, the operation buttons 6 and 7 in FIG. 1).

  As shown in FIG. 8B, in the first mode in which normal display is performed, when a minute carry is performed (S300Y), the time is updated (S308), and the normal time is displayed on the display unit. (S310).

  Here, except for the timing when the minute carry is performed based on the time signal (S300N), the presence / absence of external input is checked (S302). If there is an external input (S302Y), a screen for setting the update interval in the second mode is displayed (S304).

  Then, for example, a new update interval is set by the user's button operation (S306). For example, the update interval may be changed from 1 hour to 10 minutes that allows more accurate time display. When the setting of the update interval is completed, the normal time display is restored (S310).

  When there is no minute carry (S300N) and there is no external input (S302N), nothing is done and the display so far is maintained due to the memory characteristics of the display unit.

1.7. Update Interval and Display Example In the second mode, the electronic timepiece of the present embodiment updates and displays the time display only when the time that is the update interval has elapsed. In the second mode, low power consumption and approximate time display can be realized. At this time, in order to avoid misidentification by the user, the approximate time display needs to be clearly distinguished from the normal display. In the example of FIG. 1, the update interval is one hour, and the minute digits are displayed other than numbers (“xx”) to avoid the user from misidentifying the current time.

  9A to 10C show display examples in the second mode in the present embodiment other than the example of FIG. These displays may be selectable simultaneously with the setting of the update interval by the external input (see S306 in FIG. 8B).

  FIGS. 9A to 9C are display examples when the update interval is one hour. In FIG. 9A, in the second mode, an analog clock is displayed on the display unit 3, and an area corresponding to the hour digit of the current time in the analog clock is displayed in a different color from the other areas. As a result, the user can intuitively know when the time is.

  FIG. 9B shows the time zone explicitly in the second mode. Since the display method is clearly different from the normal time display, misidentification of the user can be avoided. Instead of the expression in FIG. 9B, an expression from what time to what time as shown in FIG. 9C may be used.

  FIG. 10A is a display example when the update interval is 30 minutes. In FIG. 10A, the first half and the second half of the 2 pm range can be distinguished. Thus, by changing the update interval from, for example, 1 hour to 30 minutes, the accuracy of the time indicated by the approximate time can be improved, although there is a slight increase in power consumption.

  FIG. 10B is a display example when the update interval is 10 minutes. In FIG. 10 (B), it is possible to know the accurate time up to the 10-minute digit. The accuracy of the time indicated by the approximate time can be further improved, and the power consumption can be suppressed as compared with the normal display.

  In this embodiment, the update interval can be switched by an external input. Therefore, the accuracy of the time indicated by the approximate time display in the second mode can be set in consideration of the balance with the power consumption.

  In this embodiment, the display mode changes to the second mode during the power save mode. Therefore, as shown in FIG. 10C, it may be clearly indicated that the normal display is not performed because of the power save mode. Since the user knows why the normal display is not performed, the misunderstanding that it is a failure is eliminated.

  As described above, when the normal time display is not performed, the electronic timepiece of the present embodiment can notify the user of the approximate time by displaying at least the hour digits while suppressing power consumption. . Therefore, by providing display modes other than the normal display, it is possible to meet the demand of the user who wants to know the time immediately while realizing low power consumption.

2. Second Embodiment A second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the electronic timepiece is an electronic timepiece with a solar cell (solar timepiece), and the display mode is switched according to the power generation state.

  In addition, the same code | symbol is attached | subjected to the same element as FIGS. 1-10C, and description is abbreviate | omitted. The display of the electronic timepiece of the second embodiment is the same as that of the first embodiment shown in FIGS. 1 and 9A to 10C, and the description thereof is omitted.

2.1. FIG. 11 is a block diagram of an electronic timepiece 1A according to this embodiment. Unlike FIG. 3, which is a block diagram of the electronic timepiece of the first embodiment, the electronic timepiece 1 </ b> A includes a solar battery 20, a power generation detection circuit 21, a charge control circuit 24, and a secondary battery 25. Moreover, although a motion sensor and a motion detection circuit may be included, description is abbreviate | omitted in FIG. The same elements as those in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted.

  The solar cell 20 is a power generation means of the electronic timepiece 1A and generates power. The charge control circuit 24 performs control for charging the secondary battery 25 with the power generated by the solar battery 20.

  The power generation detection circuit 21 detects a power generation state in the solar cell 20 and outputs a signal according to whether or not the solar cell 20 is in a power generation state to the display control circuit 14 and the timer 22. Specifically, the power generation detection circuit 21 may detect the power generated by the solar battery 20 and make the above determination. The power generation detection circuit 21 functions as power generation detection means of the electronic timepiece 1A.

  Hereinafter, the case where the power generation detection circuit 21 determines that the solar cell 20 is generating power of a predetermined value or more is expressed as “power generation detected” or “power generation state”. Other cases are expressed as a non-power generation state.

  The timer 22 of this embodiment receives a reference signal from the frequency divider circuit 12. Then, based on the signal from the power generation detection circuit 21, the time of the non-power generation state is measured. If the non-power generation state continues for a predetermined time or more, a signal indicating that is output to the display control circuit 14.

  Based on the signal from the timer 22, the display control circuit 14 changes the display mode from the first mode to the second mode if the non-power generation state continues for a predetermined time or more. The reason for waiting for the elapse of the predetermined time by the timer 22 is to avoid erroneous detection as in the first embodiment. In order to reduce power consumption as much as possible, the display control circuit 14 may immediately shift from the first mode to the second mode by detecting the non-power generation state.

  When the second mode is in the power generation state, the display control circuit 14 returns the display mode to the first mode. At this time, the reason for not waiting for the elapse of the predetermined time is to respond to the request that the user wants to immediately see the normal time display, as in the first embodiment. Note that, for the sake of careful judgment, the first mode may be returned after a predetermined time has elapsed.

2.2. Flowchart FIG. 12 is a flowchart of control performed by the display control circuit of the electronic timepiece according to this embodiment. In addition, the same code | symbol is attached | subjected to the process same as FIG. 7, and description is abbreviate | omitted. Further, the flow of the time display S20 and the normal display S30 that are not the normal display is the same as that in FIGS. 8A and 8B.

  In the flowchart of the present embodiment, S40 that determines whether or not power generation is detected is used instead of S22 of the flowchart (FIG. 7) of the first embodiment. Further, S42 that determines whether or not power generation is detected is used instead of S12 in the flowchart (FIG. 7) of the first embodiment.

  If the current display mode is the first mode (S10Y) and the power generation is detected (S42Y), the display control circuit causes the display unit to perform normal display (S30). If it is in the non-power generation state (S42N), the timer measures the time in the non-power generation state (S14). Then, it is determined that the non-power generation state continues for a predetermined time by the timer reaching a predetermined value (S16Y), the second mode is set (S18), and the time display that is not normally displayed on the display unit (S20) is performed.

  When the display mode is the second mode (S10N) and the power generation is detected (S40Y), the display control circuit returns to the first mode (S24). At this time, the timer is reset (S26), and normal display (S30) is performed on the display unit. If it is in a non-power generation state (S40N), time display (S20) which is not normally displayed on a display part is performed.

  In the electronic timepiece of this embodiment, when the solar cell is in a non-power generation state, the display mode is the second mode with low power consumption. Therefore, it is possible to make the battery last longer. Further, for example, when the electronic timepiece is a wristwatch, there is a possibility of switching to the second mode when the timepiece is hidden under clothes. Even in that case, since the approximate time is displayed in the second mode, the function as a clock is not lost.

3. Third Embodiment A third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, the display mode is switched according to the level of the power supply voltage supplied from the battery of the electronic timepiece. In addition, the same code | symbol is attached | subjected to the same element as FIGS. 1-12, and description is abbreviate | omitted.

3.1. Display Example of Electronic Timepiece FIG. 13 is a front view of the electronic timepiece 1B of the present embodiment. Similarly to the first and second embodiments, the electronic timepiece 1B of the present embodiment also has a first mode (ST1) and a second mode (ST2). The normal display in the first mode is the same as in the first and second embodiments.

  When the level of the power supply voltage decreases, the display on the display unit 3 is switched to the second mode in order to suppress power consumption and extend the battery life. The display in the second mode of the third embodiment includes a message indicating a decrease in the power supply voltage (in FIG. 13, LOW BATTERY). Therefore, the user can take appropriate measures such as moving to a place in the sun so that solar power generation is performed.

  As shown in FIG. 13, the display in the second mode displays an approximate time. Even when the power supply voltage drops, the user can grasp the approximate time so that the clock function is not lost.

  In the example of FIG. 13, the display update interval of the display unit 3 is one hour. Therefore, the minute digits are displayed other than numbers ("xx") in order to avoid the user from erroneously recognizing the minute digits that are not updated as the current time.

  When the power supply voltage becomes equal to or higher than a predetermined level, the display mode of the electronic timepiece 1B returns to the first mode and normal display is performed.

3.2. FIG. 14 is a block diagram of an electronic timepiece 1B according to this embodiment. Unlike FIG. 11, which is a block diagram of the electronic timepiece of the second embodiment, the electronic timepiece 1 </ b> B includes a battery voltage detection circuit 31. As in the second embodiment, the electronic timepiece 1B in the present embodiment charges the secondary battery 25 with the electric power generated by the solar battery 20 and uses it as a power source, but may include a primary battery.

  Moreover, although a motion sensor and a motion detection circuit may be included like 1st Embodiment, description is abbreviate | omitted in FIG. The same elements as those in FIG. 3 and FIG.

  The battery voltage detection circuit 31 detects the voltage level of the secondary battery 25 and outputs a signal according to whether or not the voltage is equal to or higher than a preset threshold voltage V1 to the display control circuit 14 and the timer 22. As described above, since the secondary battery 25 is used as a power source in the present embodiment, the battery voltage detection circuit 31 functions as a power source voltage detection unit of the electronic timepiece 1B.

  The display control circuit 14 switches the display mode to the second mode of low power consumption when the battery voltage detection circuit 31 detects a drop in the power supply voltage before the electricity stored in the secondary battery 25 is exhausted. . Then, the battery is made to last for a long time, and the user is encouraged to take appropriate measures such as charging. Specifically, a message notifying that the power supply voltage has decreased in the second mode is also displayed.

  Here, the timer 22 of the present embodiment measures the time during which the power supply voltage falls below the threshold voltage V1 (low voltage state) based on the signal from the battery voltage detection circuit 31. If the low voltage state continues for a predetermined time or longer, a signal indicating that is output to the display control circuit 14.

  Based on the signal from the timer 22, the display control circuit 14 changes the display mode from the first mode to the second mode if the low voltage state continues for a predetermined time or more. The reason for waiting for the elapse of the predetermined time by the timer 22 is to avoid erroneous detection as in the first embodiment. In order to reduce power consumption as much as possible, the display control circuit 14 may immediately shift from the first mode to the second mode by detecting a low voltage state.

  Then, when the low voltage state is lost in the second mode, the display control circuit 14 returns the display mode to the first mode. At this time, the reason for not waiting for the elapse of the predetermined time is to respond to the request that the user wants to immediately see the normal time display, as in the first embodiment. Note that, for the sake of careful judgment, the first mode may be returned after a predetermined time has elapsed.

3.3. Flowchart FIG. 15 is a flowchart of control performed by the display control circuit of the electronic timepiece according to this embodiment. In addition, the same code | symbol is attached | subjected to the same process as FIG. 7, FIG. 12, and description is abbreviate | omitted. Further, the flow of the time display S20 and the normal display S30 that are not the normal display is the same as that in FIGS. 8A and 8B.

  In the flowchart of this embodiment, instead of S22 in the flowchart of the first embodiment (FIG. 7), S44 for determining whether the power supply voltage VDD is equal to or higher than the threshold voltage V1 plus A (VDD ≧ V1 + A) is used. . A is added to provide hysteresis.

  Further, in the flowchart of the present embodiment, S46 that determines whether the power supply voltage VDD is equal to or higher than the threshold voltage V1 (VDD ≧ V1) is used instead of S12 in the flowchart (FIG. 7) of the first embodiment.

  When the current display mode is the first mode (S10Y), the display control circuit causes the display unit to perform normal display (S30) if it is not in the low voltage state (S46Y). If it is in the low voltage state (S46N), the timer times the low voltage state (S14). Then, it is determined that the low voltage state continues for a predetermined time by the timer reaching a predetermined value (S16Y), the second mode is set (S18), and the time display that is not normally displayed on the display unit. (S20) is performed. At this time, in the example of FIG. 13, a LOW BATTERY message indicating a low voltage state is also displayed.

  When the display mode is the second mode (S10N), the display control circuit returns to the first mode when the low voltage state is lost (S44Y) (S24). At this time, the timer is reset (S26), and normal display (S30) is performed on the display unit. If it is a low voltage state (S44N), time display (S20) which is not normally displayed on a display part will be performed.

  Here, in this embodiment, in the determination to return to the first mode (S44), a comparison is made using a voltage obtained by adding A to the threshold voltage V1 (V1 + A). Thereby, it can prevent returning to a 1st mode accidentally by the influence of noise etc.

  In the electronic timepiece of the present embodiment, the display mode is the second mode with low power consumption when in a low voltage state. Therefore, it is possible to make the battery last longer. Even in the constant voltage state, since the approximate time is displayed in the second mode, the clock function is not lost. The user can take an appropriate action by displaying the reason in the second mode (for example, LOW BATTERY in FIG. 13).

4). Fourth Embodiment A fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment, the display mode is switched according to whether or not the usage environment temperature of the electronic timepiece is within a predetermined range. In addition, the same code | symbol is attached | subjected to the same element as FIGS. 1-15, and description is abbreviate | omitted.

4.1. Display example of electronic timepiece FIG. 16A is a front view of an electronic timepiece 1C of the present embodiment. The electronic timepiece 1C of the present embodiment also has the first mode (ST1) and the second mode (ST2) as in the first to third embodiments. The normal display in the first mode is the same as in the first to third embodiments.

  When the use environment temperature is lower than the predetermined range, the display switching speed of the EPD is reduced, and it is necessary to apply a voltage based on the drive pulse signal for a long time. Then, power consumption increases, and the time that can be operated by the battery can be shortened.

  The display on the display unit 3 is switched to the second mode in order to reduce power consumption and extend the battery life. The display in the second mode of the fourth embodiment includes a message indicating that the use environment temperature is lower than the predetermined range (LOW TEMP in FIG. 16A). Therefore, the user can take appropriate measures such as moving from the outside to the room.

  As shown in FIG. 16, the display in the second mode displays the approximate time. Even when the display mode shifts to the second mode, the user can grasp the approximate time, so the function as a clock is not lost.

  Note that the display of digits other than numerals (“xx”) is the same as in the first embodiment, for example. When the use environment temperature falls within a predetermined range, the display mode of the electronic timepiece 1C returns to the first mode, and normal display is performed.

  Here, the second mode may be switched not only when the use environment temperature is low but also when the use environment temperature is high. When the EPD is operated at a high temperature, the quality may not be maintained due to problems such as excessive current flow.

  Therefore, even when the operating environment temperature is higher than the predetermined range, the display is performed in order to reduce the frequency of updating that requires applying the voltage based on the drive pulse signal while responding to the request of the user who wants to know the time. The mode is preferably the second mode.

  FIG. 16B illustrates a display example of the display unit 3 when the use environment temperature is higher than a predetermined range. At this time, the display in the second mode of the fourth embodiment includes a message indicating that the use environment temperature is higher than the predetermined range (in FIG. 16B, HIGH TEMP). Therefore, the user can take appropriate measures such as carrying an electronic timepiece left in the car during a hot day to the outside of the car.

4.2. FIG. 17 is a block diagram of an electronic timepiece 1C according to this embodiment. Unlike FIG. 3, which is a block diagram of the electronic timepiece of the first embodiment, the electronic timepiece 1 </ b> C includes a temperature sensor 41 and a temperature detection circuit 42.

  Although the description of the power source is omitted in FIG. 17, the electronic timepiece 1 </ b> C may include a primary battery, or may include a power generation device (solar battery) and a secondary battery. Moreover, although a motion sensor and a motion detection circuit may be included, description is abbreviate | omitted in FIG. In addition, the same code | symbol is attached | subjected to the same element as FIG.3, FIG.11, FIG.14, and description is abbreviate | omitted.

  The temperature sensor 41 is a sensor that detects the temperature of the electronic timepiece 1 </ b> C, particularly the display unit 3 (see FIG. 16). The temperature detection circuit 42 inputs a signal according to whether or not the temperature (use environment temperature) detected by the temperature sensor 41 is included in a predetermined range to the display control circuit 14 and the timer 22. The temperature sensor 41 and the temperature detection circuit 42 constitute a temperature detection unit of the electronic timepiece 1C.

  Based on the signals from the temperature detection circuit 42 and the timer 22, the display control circuit 14 switches the display mode to the second mode when the use environment temperature is not included in the predetermined range. When the temperature is low, the battery is prolonged, and when the temperature is high, the quality of the EPD 10 is not deteriorated, and the user is encouraged to take an appropriate measure. Specifically, a message that the use environment temperature exceeds a predetermined range in the second mode is also displayed.

  Here, the timer 22 of this embodiment measures the time when the use environment temperature is not included in a predetermined range (for example, 0 ° C. to 50 ° C.) based on the signal from the temperature detection circuit 42. If a high temperature state or a low temperature state outside the predetermined range continues for a predetermined time or more, a signal indicating that is output to the display control circuit 14.

4.3. Flowchart FIG. 18 is a flowchart of control performed by the display control circuit of the electronic timepiece according to this embodiment. In addition, the same code | symbol is attached | subjected to the same process as FIG.7, FIG.12, FIG.15, and description is abbreviate | omitted. Further, the flow of the time display S20 and the normal display S30 that are not the normal display is the same as that in FIGS. 8A and 8B.

  In the flowchart of the present embodiment, S48 and S50 for determining whether the use environment temperature is in a predetermined range are used instead of S22 and S12 of the flowchart of the first embodiment (FIG. 7).

  When the current display mode is the first mode (S10Y), if the use environment temperature is within a predetermined range (S50Y), the display control circuit causes the display unit to perform normal display (S30). If it is a high temperature state or a low temperature state outside the predetermined range (S50N), the timer measures the time of the high temperature state or the low temperature state (S14). Then, it is determined that the timer has continued for a predetermined time by the timer reaching a predetermined value (S16Y), the second mode is set (S18), and a time display (S20) that is not normally displayed on the display unit. Let it be done. At this time, as shown in FIGS. 16A and 16B, the reason why the normal display is not performed (LOW TEMP, HIGH TEMP) is also displayed.

  When the display environment is in the second mode (S10N), the display control circuit returns to the first mode when the operating environment temperature returns within a predetermined range (S48Y) (S24). At this time, the timer is reset (S26), and normal display (S30) is performed on the display unit. If the high temperature state or the low temperature state outside the predetermined range continues (S48N), the time display (S20) that is not the normal display is performed on the display unit.

  Here, also in the present embodiment, hysteresis may be provided in the determination to return to the first mode (S48) (see S44 in FIG. 15). Thereby, it can prevent returning to a 1st mode accidentally by the influence of noise etc.

  In the electronic timepiece according to the present embodiment, when the use environment temperature exceeds a predetermined range, the display mode is set to the second mode for low power consumption or for preventing deterioration of EPD quality. Even in this case, since the approximate time is displayed in the second mode, the function as a clock is not lost. The user can take an appropriate action by displaying the reason in the second mode.

5. Other EPD used in each of the above embodiments may be one in which black-and-white two-particle electrophoresis with black particles and white particles is performed, may be performed in one-particle electrophoresis, and other than monochrome A combination may be used.

  The memory display means is not limited to the EPD, but may be a display having other memory characteristics. For example, an ECD (Electrochromic Display), a ferroelectric liquid crystal display, a cholesteric liquid crystal display, or the like may be used.

  Furthermore, the electronic timepiece of the present invention is not limited to a wristwatch, and may be a table clock, a wall clock, a pocket watch, or the like.

  The present invention is not limited to these exemplifications, and includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 100 ... Electronic timepiece, 2 ... Clock case, 3,103 ... Display part, 4 ... Band, 6 ... Operation button, 7 ... Operation button, 10 ... EPD (electrophoretic display device), 11 DESCRIPTION OF SYMBOLS ... Oscillation circuit, 12 ... Frequency divider circuit, 13 ... Time counter, 14 ... Display control circuit, 15 ... Switch, 16 ... Switch, 17 ... Time adjustment circuit, 18 ... Control signal, 20 ... Solar cell, 21 ... Power generation detection circuit , 22 ... timer, 24 ... charge control circuit, 25 ... secondary battery, 31 ... battery voltage detection circuit, 35, 35A, 35B ... pixel electrode, 37 ... common electrode, 40, 40A, 40B ... pixel, 41 ... temperature sensor , 42 ... temperature detection circuit, 43 ... motion sensor, 44 ... motion detection circuit, 48 ... driving TFT (Thin Film Transistor), 49 ... low potential power line (Vss), 50 ... high potential power line (Vdd), 55 Common electrode wiring (Vcom), 60 ... EPD control unit, 61 ... scanning line driving circuit, 62 ... data line driving circuit, 63 ... controller, 64 ... common power supply modulation circuit, 66 ... scanning line, 68 ... data line, 70 ... Latch circuit, 80 ... switch circuit, 91 ... first pulse signal line (S ₁ ), 92 ... second pulse signal line (S ₂ ), 120 ... microcapsule, 126 ... black particles, 127 ... white particles, 130 ... Element substrate 131 ... Counter substrate 132 ... Electrophoretic element 160 ... Storage unit 350 ... Drive electrode layer 360 ... Electrophoretic display layer 370 ... Common electrode layer ST1 ... First mode ST2 ... Second mode

Claims (9)

Power supply voltage detection means for detecting the voltage of the power supply;
A time measuring means for measuring time;
Memory display means,
Control means for controlling the display of the display means,
The control means includes
Switching control for switching the display mode of the display means between a first mode for normal display and a second mode having a display update interval longer than the first mode;
In the first mode, the display unit displays the time,
The switching control from the first mode to the second mode is performed when the voltage value detected by the power supply voltage detection means in the first mode is less than a predetermined value,
An electronic timepiece that causes the display means to display at least the time digits of the time in the second mode. The electronic timepiece according to claim 1,
The control means includes
An electronic timepiece that displays the reason why the normal display is not performed in the second mode. The electronic timepiece according to claim 1,
The control means includes
An electronic timepiece that updates the display of the display means based on a change in the time digit of the time in the second mode. The electronic timepiece according to claim 1,
The control means includes
An electronic timepiece that displays an analog timepiece on the display means in the second mode and displays an area corresponding to the time digit of the time in the analog timepiece in a color different from other areas. The electronic timepiece according to claim 1,
The control means includes
An electronic timepiece that updates the display of the display means based on a change of the tenth digit of the time in the second mode. The electronic timepiece according to claim 1,
The control means includes
An electronic timepiece that updates the display of the display means based on the time changing to 0 minutes or 30 minutes in the second mode. The electronic timepiece according to claim 1,
Including input means for receiving external instructions,
The control means includes
An electronic timepiece that determines a display update interval of the display means in the second mode based on the instruction received by the input means. The electronic timepiece according to claim 1,
The control means includes
An electronic timepiece that performs the switching control from the second mode to the first mode when the voltage value detected by the power supply voltage detection means in the second mode is a predetermined value or more. A control method for an electronic timepiece including a power supply voltage detection means for detecting a voltage of a power supply, a timekeeping means for measuring time, and a memory display means,
A first mode in which the display mode of the display means is a first mode for normal display, and the time is displayed on the display means;
When the voltage value detected by the power supply voltage detection means in the first mode is less than a predetermined value, the display mode of the display means is changed to the second mode having a display update interval longer than that of the first mode. A second step of switching;
And a third step of causing the display means to display at least the time digits of the time in the second mode.