Time measuring device

Abstract

To prevent timing for inverting the polarity of volts alternating current to be applied to a liquid crystal display panel in a fixed polarity inversion cycle and timing for writing image date in the liquid crystal display panel from overlapping with each other with simple constitution.SOLUTION: The time measuring device includes an event holding unit that holds an event during a period of a first standby operation time immediately before inversion of the polarity of an AC voltage applied to the liquid crystal panel and a second standby operation time immediately after the inversion of the polarity of the AC voltage, a display update determination unit that determines whether or not the held event requires update of the display of the liquid crystal panel after the periods of the first standby operation time and the second standby operation time elapse, and an image data output control unit that writes image data of the event determined to require update of the display of the liquid crystal panel to the liquid crystal panel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a time measurement device. [Background technology]

[0002] To maintain the reliability of the liquid crystal, it has been recommended that an AC voltage whose polarity reverses periodically be applied to the liquid crystal panel from outside the liquid crystal panel, as used in digital electronic watches and the like. It has also been recommended that the time ratio between the period when the AC voltage is positive and the period when it is negative (the period when the AC voltage is positive and negative) be 50% each (a duty ratio of 50%). However, if the timing when the polarity of the AC voltage reverses coincides with the timing when image data to be displayed on the liquid crystal panel is written to the liquid crystal panel, there is a possibility that the image data will not be written properly due to the effects of an increased electrical load, etc. Patent Documents 1 to 3, for example, are known as conventional techniques for addressing this issue.

[0003] The technology described in Patent Document 1 reverses the polarity of the AC voltage at a fixed cycle that is shifted a fixed time from a reference time, and if it is determined that the period for transferring image data is included in the transfer waiting period for reversing the polarity of the AC voltage, the image data is transferred after the transfer waiting period has elapsed. The technology described in Patent Document 2 inverts the polarity of the AC voltage at a fixed polarity inversion period, and outputs image data in synchronization with the polarity inversion period and at a period equal to an integral fraction of the polarity inversion period. The technology described in Patent Document 3 delays the reversal of the polarity of the AC voltage while the enable signal for writing image data is being output, when the timing of the reversal of the polarity of the AC voltage overlaps, and delays the output of the enable signal while the polarity of the AC voltage is being reversed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5450784 [Patent Document 2] Patent No. 6866817 [Patent Document 3] Patent No. 7187792 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 requires a process to determine whether the period for transferring image data is included in the transfer waiting period for reversing the polarity of the AC voltage, which makes the software complex. Furthermore, the technology described in Patent Document 2 mentioned above is fine during periods when the display is updated in synchronization with the polarity reversal cycle, like the time on a clock, but if the display is updated asynchronously with the polarity reversal cycle due to a person operating a button, etc., there is a possibility that the timing of the polarity reversal of the AC voltage and the timing of the display update, i.e., the timing of the output of image data, may overlap. Furthermore, in the technology described in Patent Document 3, the polarity reversal of the AC voltage is delayed while the enable signal is being output, so it is not possible to maintain a 50% duty ratio during the positive and negative periods of the AC voltage.

[0006] The present invention has been made in consideration of these circumstances, and its purpose is to prevent, with a simple configuration, the timing at which the polarity of the AC voltage applied to the liquid crystal panel is reversed at a fixed polarity reversal period from overlapping with the timing at which image data is written to the liquid crystal panel. [Means for solving the problem]

[0007] One aspect of the present invention is a time measurement device having a time measurement function and displaying an image on a liquid crystal panel by writing image data to the liquid crystal panel, the time measurement device comprising: a polarity control unit that inverts the polarity of an AC voltage applied to the liquid crystal panel at a fixed polarity inversion period; an event reception unit that receives an event that may cause an update of the display of the liquid crystal panel; an event reservation unit that reserves the event received by the event reception unit for a period of a fixed first standby operation time immediately before the reversal of the polarity of the AC voltage and a fixed second standby operation time immediately after the reversal of the polarity of the AC voltage; a display update determination unit that determines whether the reserved event requires an update of the display of the liquid crystal panel after the first standby operation time and the second standby operation time have elapsed; and an image data output control unit that writes image data of an event that is determined to require an update of the display of the liquid crystal panel to the liquid crystal panel, wherein the first standby operation time includes one unit of time for writing image data to the liquid crystal panel and an image data writing prohibition time immediately before the reversal of the polarity of the AC voltage, and the second standby operation time includes an image data writing prohibition time immediately after the reversal of the polarity of the AC voltage. One aspect of the present invention is a time measurement device in which, in the above-mentioned time measurement device, the image data output control unit writes to the liquid crystal panel, after the second standby operation time period has elapsed, the portion of the image data of the event for which it has been determined that the display of the liquid crystal panel needs to be updated, that has not been completely written to the liquid crystal panel by the end of the first standby operation time period. One aspect of the present invention is a time measurement device in which, among the image data of the event for which it has been determined that the display of the liquid crystal panel needs to be updated, the portion of the image data that is completed writing to the liquid crystal panel by the end of the first standby operation time period and the portion of the image data that is written to the liquid crystal panel after the second standby operation time period have elapsed are written to different addresses on the liquid crystal panel. One aspect of the present invention is a time measurement device in which, of the image data of the event for which it has been determined that the display of the liquid crystal panel needs to be updated, a portion of the image data that is completed being written to the liquid crystal panel by the end of the first standby operation time period and a portion of the image data that is written to the liquid crystal panel after the second standby operation time period have elapsed are displayed in different parts of the display area of ​​the liquid crystal panel. One aspect of the present invention is a time measurement device, wherein the event is a request for a specified process within the time measurement device that occurs after the time measurement device receives communication from a control unit having a specified control function within the time measurement device. One aspect of the present invention is a time measurement device, wherein the event is a request for a specified process that is initiated by a hardware interrupt that occurs within the time measurement device to a control unit having a specified control function within the time measurement device. One aspect of the present invention is the time measurement device described above, wherein the event is a request to update the display of the time measured inside the time measurement device. One aspect of the present invention is the time measurement device described above, wherein the event is a request to update the display of the time measured inside the time measurement device. One aspect of the present invention is a time measurement device, wherein the polarity inversion period is a non-integer multiple of a fixed period at which an update of the display of the liquid crystal panel occurs due to a specific function possessed by the time measurement device. One aspect of the present invention is the above-mentioned time measurement device, wherein the event is a request for a predetermined process for each button operated after accepting operation of a button provided on the time measurement device. One aspect of the present invention is a time measurement device, wherein the event is a request for a specified process within the time measurement device that occurs after communication from an external device is received within the time measurement device. One aspect of the present invention is the time measurement device described above, wherein the event is a request for a predetermined process that occurs in response to a change in an internal or external state of the time measurement device. One aspect of the present invention is a time measurement device in which, in the above-mentioned time measurement device, writing image data to the liquid crystal panel is an operation of transmitting an address indicating the display position on the liquid crystal panel, transmitting image data, and transmitting a write command, which is executed once or repeatedly executed multiple times, and the single writing operation is executed multiple times in succession to write image data that is simultaneously displayed in the display area of ​​the liquid crystal panel, and if the timing for reversing the polarity of the AC voltage comes during the multiple consecutive executions of the single writing operation, the single writing operation currently being executed is completed, and the remaining one or more single writing operations are executed after the second standby operation time period has elapsed. One aspect of the present invention is a time measurement device that is provided in a digital electronic clock, a combination clock having a digital display function and a hands display function, a stopwatch, or a timer. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent, with a simple configuration, the timing at which the polarity of the AC voltage applied to the liquid crystal panel is inverted at a fixed polarity inversion period from overlapping with the timing at which image data is written to the liquid crystal panel. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram illustrating an example of the configuration of a time measurement device according to an embodiment. [Figure 2] 1 is a time chart showing an example of the operation of a time measurement device according to an embodiment. [Figure 3] 1 is a time chart showing an example of the operation of a time measurement device according to an embodiment. [Figure 4] 1 is a time chart showing an example of the operation of a time measurement device according to an embodiment. [Figure 5] 1 is a time chart showing an example of the operation of a time measurement device according to an embodiment. [Figure 6] 1 is a time chart showing an example of the operation of a time measurement device according to an embodiment. [Figure 7] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 8] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 9] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 10] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 11] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 12] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 13] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 14] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 15] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. [Figure 16] FIG. 10 is a diagram illustrating a processing flow executed by a time measurement device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a block diagram showing an example of the configuration of a time measurement device 1 according to one embodiment. The time measurement device 1 includes an oscillator 10, a quartz oscillator 20, a first control device 100, a second control device 200, a display module 300, a button 30, a power supply (battery) 40, a voltage conversion circuit 41, a power supply control circuit 42, and a display power supply control circuit 43.

[0011] The first control device 100 mainly controls the display module 300. The second control device 200 mainly measures time. The oscillator 10 generates a signal with a frequency that forms the basis of the operating frequency of the first control device 100. The oscillator 10 may be a quartz oscillator or a type of oscillator other than a quartz oscillator. The quartz oscillator 20 generates a signal with a frequency that forms the basis of the operating frequency of the second control device 200. The frequency of the signal generated by the quartz oscillator 20 is, for example, 32.768 kHz.

[0012] The display module 300 includes a liquid crystal panel 301 , an image data (image data) input circuit 302 , a polarity signal input circuit 303 , and a reset signal input circuit 304 .

[0013] Liquid crystal panel 301 displays image data written from first control device 100 via image data input circuit 302. A plurality of pixels for displaying images are arranged in the display area of ​​liquid crystal panel 301. Each pixel is provided with a memory element for storing image data and a display element for displaying the image data stored in the memory element. Liquid crystal panel 301 is a so-called MIP (memory-in-pixel) liquid crystal.

[0014] Polarity signal input circuit 303 receives a polarity inversion signal (VCOM signal) from first control device 100. The VCOM signal is a signal that indicates the inversion timing for inverting the polarity of the AC voltage applied to liquid crystal panel 301 at a regular interval. An AC voltage whose polarity is inverted at the inversion timing indicated by the VCOM signal is applied to liquid crystal panel 301. As a result, an AC voltage whose polarity is inverted at a regular interval is applied to liquid crystal panel 301. This contributes to maintaining the reliability of the liquid crystal of liquid crystal panel 301.

[0015] Furthermore, it is preferable that the VCOM signal have a 50% time ratio (50% duty cycle) between the period when the AC voltage is positive and the period when the AC voltage is negative (positive and negative periods of the AC voltage). By making the duty cycle of the positive and negative periods of the AC voltage of the VCOM signal 50%, an AC voltage whose polarity is reversed at a duty cycle of 50% for the positive and negative periods of the AC voltage is applied to the liquid crystal panel 301. This contributes to maintaining the reliability of the liquid crystal of the liquid crystal panel 301.

[0016] The reset signal input circuit 304 receives a reset signal for resetting the display module 300 from the first control device 100. The reset signal received by the reset signal input circuit 304 resets the display module 300.

[0017] The button 30 is operated by the user, and by operating the button 30, the user can cause the time measurement device 1 to perform a predetermined operation.

[0018] The power supply 40 supplies power consumed by the time measurement device 1. The voltage conversion circuit 41 converts the voltage of the power supply 40 into an operating voltage (e.g., 3.3 V) for the first control device 100, the second control device 200, and the display module 300. The power supply control circuit 42 controls the power supply for the first control device 100. The display power supply control circuit 43 controls the power supply for the display module 300. The power supply 40 is, for example, a coin lithium battery (CR battery: 3 V). The voltage conversion circuit 41 is configured as a self-oscillating DC-DC conversion circuit using an inductor or a charge pump boost circuit using a capacitor.

[0019] The first control device 100 includes an oscillator circuit 101, a frequency divider circuit 102, a timer circuit 103, a wireless communication circuit 104, a first control unit 105, a ROM (read-only memory) 106, a RAM (random access memory) 107, communication circuits 108 and 109, N input circuits 110, and an output circuit 111.

[0020] The oscillator circuit 101 generates a signal of a predetermined frequency based on the signal of the frequency generated by the vibrator 10. The frequency divider circuit 102 divides the signal of the predetermined frequency generated by the oscillator circuit 101 to generate a signal of the operating frequency of the first control unit 105. The timer circuit 103 measures a predetermined timer time using the signal of the predetermined frequency generated by the oscillator circuit 101. The timer circuit 103 generates a hardware interrupt "timer interrupt" to the first control unit 105 when the measurement of the predetermined timer time has finished.

[0021] The wireless communication circuit 104 performs wireless communication with an external device of the time measurement device 1.

[0022] Of the control functions of the time measurement device 1, the first control unit 105 has a function of mainly controlling the display module 300. The first control unit 105 has a CPU (Central Processing Unit) and realizes various functions by executing programs stored in the ROM 106. The first control unit 105 has, as its functional units, an event receiving unit 121, an event reserving unit 122, a display update determining unit 123, an image data output control unit 124, and a polarity control unit 125.

[0023] The ROM 106 stores data such as programs executed by the CPU of the first control unit 105 and default values ​​of various parameters. The RAM 107 is a memory used by the first control unit 105 for temporarily storing data.

[0024] The communication circuit 108 communicates with the display module 300 to write image data to the liquid crystal panel.

[0025] The communication circuit 109 communicates with the second control device 200. The communication circuit 109 receives, for example, timing data from the second control device 200.

[0026] The input circuits 110 receive signals output from the corresponding output circuits 210 of the second control device 200. For example, one input circuit 110 receives a display update timing signal output from the corresponding output circuit 210 of the second control device 200. For example, one input circuit 110 receives a button input notification signal output from the corresponding output circuit 210 of the second control device 200.

[0027] The output circuit 111 transmits a VCOM signal to the display module 300. The output circuit 111 also transmits a reset signal to the display module 300. The output circuit 111 also transmits a signal that controls the power supply of the display module 300 to the display power supply control circuit 43.

[0028] The polarity control unit 125 inverts the polarity of the AC voltage applied to the liquid crystal panel 301 at a fixed polarity inversion period (e.g., 0.99 seconds) based on an interrupt signal from the timer circuit 103. Furthermore, the polarity control unit 125 may invert the polarity of the AC voltage applied to the liquid crystal panel 301 at a duty ratio of 50% for the positive and negative periods of the AC voltage. The polarity control unit 125 transmits a VCOM signal to the display module 300 via the output circuit 111. For example, the polarity control unit 125 transmits a VCOM signal to the display module 300 via the output circuit 111, the VCOM signal inverting the polarity of the AC voltage applied to the liquid crystal panel 301 at a fixed polarity inversion period and at a duty ratio of 50% for the positive and negative periods of the AC voltage.

[0029] The event receiving unit 121 receives an event that may cause the display on the liquid crystal panel 301 to be updated. For example, an event is a request for a predetermined process inside the time measurement device 1 that occurs after the time measurement device 1 receives communication from a control unit having a predetermined control function inside the time measurement device 1. An example of a control unit having a predetermined control function inside the time measurement device 1 is the second control unit 205, which will be described later. The second control unit 205 has a function of controlling time measurement (a time counting unit 221 and a stopwatch (STW) counting unit 222). For example, an event is a request for time update processing that occurs after the first control unit 105 receives a time update notification from the time counting unit 221. For example, an event is a request for a predetermined process that is initiated by a hardware interrupt that occurs inside the time measurement device 1 to a control unit that has a predetermined control function inside the time measurement device 1. An example of a control unit that has a predetermined control function inside the time measurement device 1 is the second control unit 205 (the time counter unit 221 and the STW counter unit 222). For example, an event is a request for a process to update the display of the stopwatch time that is initiated by a hardware interrupt that occurs to the STW counter unit 222 (for example, an interrupt signal with a predetermined frequency such as 1 Hz or 10 Hz). For example, the event is a request to update the display of the time measured inside the timing device 1. For example, the event is a request to update the display of the time measured inside the timing device 1.

[0030] The event may also be an event that originates outside the time measurement device 1. For example, an event is a request for a predetermined process for each button operated after the operation of the button 30 is accepted. For example, an event is a request for a predetermined process inside the time measurement device 1 that occurs after the time measurement device 1 receives communication from an external device of the time measurement device 1. For example, an event is a request for a predetermined display update process that occurs after the wireless communication circuit 104 receives wireless communication from an external device of the time measurement device 1. For example, an event is a request for a predetermined process that occurs in response to a change in the internal or external state of the time measurement device 1.

[0031] The polarity inversion period may be a non-integer multiple of the fixed period at which the display of the liquid crystal panel 301 is updated due to a specific function of the time measurement device 1. For example, the polarity inversion period may be a non-integer multiple of the fixed period at which the time measured by the time measurement device 1 is displayed. For example, the polarity inversion period may be a non-integer multiple of the fixed period at which the time measured by the time measurement device 1 (e.g., the time measured by a stopwatch) is displayed. For example, if the period at which the time display is updated is 1 Hz, the polarity inversion period may be a non-integer multiple of 0.91 to 0.99 times 1 Hz. For example, if the period at which the time display is flashed is 8 Hz, the polarity inversion period may be a non-integer multiple of 7.28 to 7.92 times 8 Hz. For example, if the period at which the time display is flashed is 10 Hz, the polarity inversion period may be a non-integer multiple of 9.1 to 9.9 times 10 Hz. This reduces the possibility that the timing of polarity reversal of the AC voltage applied to the liquid crystal panel 301 will overlap with the timing of display update, i.e., the timing of image data output, when the event is caused by an event external to the time measurement device 1. Note that the non-integer multiple value is not a value that is caused by the frequency deviation of the crystal oscillator 20 or the oscillator 10. For example, a 0.99 second period, where the polarity reversal period is 0.99 times 1 Hz, differs from 1.0 second by 328 cycles of the 32,768 Hz period of the oscillator circuit 101, which is larger than the frequency deviation and within a range that can be controlled to a desired value.

[0032] The event reserving unit 122 reserves the event accepted by the event accepting unit 121 for a period of a fixed first standby operation time immediately before the polarity of the AC voltage applied to the liquid crystal panel 301 is reversed and a fixed second standby operation time immediately after the polarity of the AC voltage is reversed. The event reserving unit 122 is, for example, a hardware interrupt generating function in the first control unit 105 or an event queue.

[0033] The first standby operation time includes one unit of time for writing image data to the liquid crystal panel 301 and an image data writing inhibition time immediately before the polarity of the AC voltage applied to the liquid crystal panel 301 is reversed. In this embodiment, the first standby operation time is the total time of one unit of time for writing image data to the liquid crystal panel 301 and an image data writing inhibition time immediately before the polarity of the AC voltage applied to the liquid crystal panel 301 is reversed.

[0034] One unit of time for writing image data to the liquid crystal panel 301 is the time required for one write operation, which may be an operation of transmitting an address indicating a display position on the liquid crystal panel 301, transmitting image data, and transmitting a write command once or repeatedly performed multiple times. An example of one unit of time for writing image data to the liquid crystal panel 301 is one row of the array of multiple pixels in the display area of ​​the liquid crystal panel 301.

[0035] The second standby operation time includes a time during which writing of image data is prohibited immediately after reversal of the polarity of the AC voltage applied to the liquid crystal panel 301. In this embodiment, the second standby operation time is a time during which writing of image data is prohibited immediately after reversal of the polarity of the AC voltage applied to the liquid crystal panel 301.

[0036] The display update determination unit 123 determines whether the event requires updating the display on the liquid crystal panel 301. After the first standby operation time and the second standby operation time have elapsed, the display update determination unit 123 determines whether the pending event requires updating the display on the liquid crystal panel 301.

[0037] The image data output control unit 124 writes image data of an event for which it has been determined that updating of the display on the liquid crystal panel 301 is necessary to the liquid crystal panel 301. The image data output control unit 124 writes, to the liquid crystal panel 301, a portion of the image data of an event for which it has been determined that updating of the display on the liquid crystal panel 301 is necessary, which portion has not been completely written to the liquid crystal panel 301 by the end of the first standby operation time period, after the second standby operation time period has elapsed.

[0038] The second control device 200 includes an oscillator circuit 201, a frequency divider circuit 202, a timer circuit 203, a 1 kHz counter circuit 204, a second control unit 205, a ROM 206, a RAM 207, an input circuit 208, a communication circuit 209, and N output circuits 210.

[0039] The oscillator circuit 201 generates a signal of a predetermined frequency based on the signal of the frequency generated by the crystal oscillator 20. The frequency divider circuit 202 divides the signal of the predetermined frequency generated by the oscillator circuit 201 to generate a signal of the operating frequency of the second control device 200. The frequency divider circuit 202 also divides the signal of the predetermined frequency generated by the oscillator circuit 201 to generate a signal of the operating frequency of the 1 kHz counter circuit 204. The frequency divider circuit 202 generates a 1 Hz interrupt signal necessary for updating the time display. The frequency divider circuit 202 also generates an 8 Hz interrupt signal necessary for flashing the display when the time is corrected, etc. The operation of the frequency divider circuit 202 is reset by a reset signal from the second control unit 205, for example, when the seconds of the time are adjusted. However, because the timer circuit 103 is not reset at this time, the timing of polarity inversion of the VCOM signal does not change.

[0040] The timer circuit 203 measures a predetermined timer time using a signal of a predetermined frequency generated by the oscillator circuit 201. When the timer circuit 203 has finished measuring the predetermined timer time, it generates a hardware interrupt "timer interrupt" to the second control unit 205. The 1 kHz counter circuit 204 generates 1 kHz from the 2048 Hz generated by the divider circuit 202, performs decimal counting, and generates a 10 Hz interrupt signal and a 1 Hz interrupt signal of the 1 kHz counter circuit 204 that are necessary for updating the stopwatch display. The 10 Hz interrupt signal and the 1 Hz interrupt signal of the 1 kHz counter circuit 204 generate respective hardware interrupts to the second control unit 205.

[0041] The second control unit 205 has a function of mainly controlling time measurement among the control functions of the time measurement device 1. The second control unit 205 has a CPU and realizes various functions by executing programs stored in the ROM 206. The second control unit 205 has a time measuring unit 221 and a stopwatch (STW) measuring unit 222 as its functional units.

[0042] The ROM 206 stores data such as programs executed by the CPU of the second control unit 205 and default values ​​of various parameters. The RAM 207 is a memory used by the second control unit 205 for temporarily storing data.

[0043] The time counting unit 221 counts the time. The STW counting unit 222 counts the time of a stopwatch.

[0044] The input circuit 208 receives a signal indicating the state of the button 30 operated by the user. The communication circuit 209 communicates with the first control device 100. The communication circuit 209 transmits, for example, timing data to the first control device 100. The output circuit 210 outputs a signal to the corresponding input circuit 110 of the first control device 100. For example, one output circuit 210 outputs a display update timing signal to the corresponding input circuit 110 of the first control device 100. For example, one output circuit 210 outputs a button input notification signal to the corresponding input circuit 110 of the first control device 100.

[0045] Next, the operation of the time measurement device 1 according to this embodiment will be described.

[0046] An example of the operation of the time measurement device 1 according to this embodiment will be described with reference to Figures 2 to 6. Figures 2 to 6 are time charts showing an example of the operation of the time measurement device 1 according to this embodiment.

[0047] [Example A1] 2, operation example A1 is a case where there is no reversal of the polarity of the VCOM signal during update of the display on the liquid crystal panel 301. In operation example A1, as illustrated in FIG. 3, when an event occurs, it is not during the first standby operation time period or the second standby operation time period, so it is immediately determined that the display on the liquid crystal panel 301 needs to be updated due to the event that has occurred, and image data is written to the liquid crystal panel 301.

[0048] In this embodiment, writing image data to the liquid crystal panel 301 is performed by transmitting an address indicating a display position on the liquid crystal panel 301, transmitting image data, and transmitting a write command once or repeatedly multiple times, and this single writing operation is performed multiple times in succession to write image data that is simultaneously displayed in the display area of ​​the liquid crystal panel 301. In the example of Fig. 3, image data that is simultaneously displayed on the first to ninth rows in the display area of ​​the liquid crystal panel 301 is written to the liquid crystal panel 301 by performing nine writing operations in row units in succession.

[0049] [Operation example A2] In Figure 2, operational example A2 is a case where the display on the liquid crystal panel 301 is not updated while the polarity of the VCOM signal is being inverted. In operational example A2, as illustrated in Figure 4, when a VCOM timer that measures a fixed polarity inversion period times out, the polarity of the VCOM signal is inverted after waiting for a first standby operation time. After the polarity of the VCOM signal is inverted, the polarity of the VCOM signal is inverted after waiting for a second standby operation time. Note that after one unit of time for writing image data has elapsed immediately after the start of the first standby operation time and during the second standby operation time, writing of image data to the liquid crystal panel 301 is forcibly prohibited by making the chip select signal SCS to the liquid crystal panel 301 inactive (LOW).

[0050] [Example of operation A3] 2, operation example A3 is a case where the polarity of the VCOM signal is inverted during update of the display of the liquid crystal panel 301. In operation example A3, as illustrated in FIG. 5, of the image data of an event for which it is determined that update of the display of the liquid crystal panel 301 is required, writing of the image data up to the nth row to the liquid crystal panel 301 is completed by the end of the first standby operation time period, but writing of the image data from the "n+1"th row onwards to the liquid crystal panel 301 is not completed by the end of the first standby operation time period. Writing of the image data from the "n+1"th row onwards, which is the portion of the image data that is not completed to be written to the liquid crystal panel 301 by the end of the first standby operation time period, is written to the liquid crystal panel 301 after the elapse of the second standby operation time period.

[0051] Of the image data of an event for which it is determined that the display on the liquid crystal panel 301 needs to be updated, the portion of the image data that is completely written to the liquid crystal panel 301 before the first standby operation time period ends (image data up to the nth row in the example of Figure 5) and the portion of the image data that is written to the liquid crystal panel 301 after the second standby operation time period has elapsed (image data from the "n+1"th row onwards in the example of Figure 5) have different addresses written to the liquid crystal panel 301.

[0052] Of the image data of an event for which it is determined that the display on the liquid crystal panel 301 needs to be updated, the portion of the image data that is completely written to the liquid crystal panel 301 before the first standby operation time period ends (image data up to the nth row in the example of Figure 5) and the portion of the image data that is written to the liquid crystal panel 301 after the second standby operation time period has elapsed (image data from the "n+1"th row onwards in the example of Figure 5) are displayed in different parts of the display area of ​​the liquid crystal panel 301.

[0053] An operation of transmitting an address indicating the display position on the liquid crystal panel 301, transmitting image data, and transmitting a write command once or repeatedly performed multiple times is considered to be one write operation, and when the timing for reversing the polarity of the AC voltage applied to the liquid crystal panel 301 comes during multiple consecutive write operations, the currently performed one write operation (the write operation of the image data on the nth row in the example of Figure 5) is completed, and the remaining one or multiple one write operations (the write operations of the image data on the "n+1"th row and beyond in the example of Figure 5) are performed after the second standby operation time period has elapsed.

[0054] [Example A4] In FIG. 2, operation example A4 is a case where an event including updating the display of the liquid crystal panel 301 occurs while the polarity of the VCOM signal is inverted. In operation example A4, as illustrated in FIG. 6, even if an event occurs, the event is put on hold during the first standby operation time and the second standby operation time. Next, after the first standby operation time and the second standby operation time have elapsed, it is determined whether the put on hold event requires updating the display of the liquid crystal panel 301. Next, image data for an event that is determined to require updating the display of the liquid crystal panel 301 is written to the liquid crystal panel 301. This writing to the liquid crystal panel 301 occurs after the second standby operation time has elapsed.

[0055] The flow of processing executed by the time measurement device 1 according to this embodiment will be described with reference to Figures 7 to 16. Figures 7 to 16 are diagrams showing the flow of processing executed by the time measurement device 1 according to this embodiment. Hereinafter, the first control unit 105 may be referred to as "control unit 1," and the second control unit 205 may be referred to as "control unit 2."

[0056] [Processing flow for turning on the power of the control unit 1] The processing flow relating to power-on of the first control unit 105 will be described with reference to Fig. 7. Fig. 7 is a diagram showing the processing flow relating to power-on of the first control unit 105 according to this embodiment.

[0057] (Step S101) The control unit 2 turns on the power supply of the control unit 1.

[0058] (Step S102) The control unit 1 executes its own initialization process.

[0059] (Step S103) The control unit 1 turns on the power of the display module 300 (display unit).

[0060] (Step S104) The image data output control unit 124 of the control unit 1 writes initial image data to the liquid crystal panel 301. The initial image data is, for example, image data without full-screen display.

[0061] (Step S105) The polarity control unit 125 of the control unit 1 starts a timer (VCOM timer) for inverting the polarity of the VCOM signal. The VCOM timer is a timer that measures a fixed polarity inversion period.

[0062] (Step S106) The control unit 1 notifies the control unit 2 that its startup has been completed.

[0063] (Step S107) The control unit 2 notifies the control unit 1 of the current state (mode, etc.) of each function and the current time.

[0064] (Step S108) The control unit 1 performs a predetermined update of the display on the liquid crystal panel 301 in accordance with the mode of each function. For example, if the current mode is the time display mode, the current time is displayed.

[0065] [Processing flow for turning off the power of the control unit 1] The processing flow relating to power-off of the first control unit 105 will be described with reference to Fig. 8. Fig. 8 is a diagram showing the processing flow relating to power-off of the first control unit 105 according to this embodiment.

[0066] (Step S201) The control unit 2 notifies the control unit 1 of an advance notice of power-off.

[0067] (Step S202) The control unit 1 sets all the control ports of the display module 300 to inactive output (LOW output).

[0068] (Step S203) The control unit 1 turns off the power supply to the display module 300.

[0069] (Step S204) The control unit 1 notifies the control unit 2 that the preparation for power-off has been completed and the current state (mode, etc.) of each function.

[0070] (Step S205) The control unit 2 turns off the power supply to the control unit 1.

[0071] [Processing flow for inverting the polarity of the VCOM signal] The processing flow relating to the inversion of the polarity of the VCOM signal will be described with reference to Fig. 9. Fig. 9 is a diagram showing the processing flow relating to the inversion of the polarity of the VCOM signal according to this embodiment.

[0072] (Step S301) The polarity control unit 125 of the control unit 1 determines whether the VCOM timer has timed out. If the VCOM timer has timed out, the process proceeds to step S302. If the VCOM timer has not timed out, the process continues to step S301.

[0073] (Step S302) The polarity control unit 125 restarts the VCOM timer.

[0074] (Step S303) The polarity control unit 125 waits for a first standby operation time.

[0075] (Step S304) The polarity control unit 125 inverts the polarity of the VCOM signal after the first standby operation time has elapsed.

[0076] (Step S305) The polarity control unit 125 waits for a second standby operation time.

[0077] (Step S306) Polarity control unit 125 checks whether there are any pending events. Specifically, it checks whether there are any events registered in the pending event information, which will be described later. Events registered in the pending event information are "pending events." If there are any pending events (if there are any events registered in the pending event information), proceed to step S307; if there are no pending events (if there are no events registered in the pending event information), return to step S301.

[0078] (Step S307) Display update determination unit 123 of control unit 1 determines whether the pending event requires updating the display on liquid crystal panel 301. If the pending event requires updating the display on liquid crystal panel 301, image data output control unit 124 of control unit 1 writes image data of the pending event to liquid crystal panel 301.

[0079] [Processing flow for updating the display on the LCD panel] The processing flow relating to updating the display on the liquid crystal panel 301 will be described with reference to Fig. 10. Fig. 10 is a diagram showing the processing flow relating to updating the display on the liquid crystal panel 301 according to this embodiment.

[0080] (Step S401) The image data output control unit 124 of the control unit 1 creates image data for an event that requires updating of the display on the liquid crystal panel 301.

[0081] (Step S402) The image data output control unit 124 identifies an area in the display area of ​​the liquid crystal panel 301 where the display is to be updated (an area (address) where the image data is to be rewritten).

[0082] (Step S403) The image data output control unit 124 makes the chip select signal SCS to the liquid crystal panel 301 active (HIGH).

[0083] (Step S404) The image data output control unit 124 waits for a specified waiting time immediately after making the chip select signal SCS active (HIGH).

[0084] (Step S405) The image data output control unit 124 transmits an address indicating the display position on the liquid crystal panel 301.

[0085] (Step S406) The image data output control unit 124 transmits the image data.

[0086] (Step S407) The image data output control unit 124 transmits an image data write signal (write command).

[0087] (Step S408) The image data output control unit 124 determines whether writing of all image data for the event has been completed. If writing of all image data for the event has been completed, the process in Fig. 10 ends. On the other hand, if there is image data that has not yet been written, the process proceeds to step S409.

[0088] (Step S409) The image data output control unit 124 determines whether or not it is during the first standby operation time. If it is during the first standby operation time, the process proceeds to step S410. On the other hand, if it is not during the first standby operation time, the process proceeds to step S405, and writes the image data that has not yet been written to the liquid crystal panel 301.

[0089] (Step S410) The image data output control unit 124 determines whether the first standby operation time or the second standby operation time is in progress. If the first standby operation time or the second standby operation time is in progress (YES in step S410), the process waits until the first standby operation time or the second standby operation time has ended. On the other hand, if the first standby operation time or the second standby operation time has ended (NO in step S410), the process proceeds to step S405, and the image data that has not yet been written is written to the liquid crystal panel 301.

[0090] [Processing flow for time counting] The processing flow relating to time counting will be described with reference to Fig. 11. Fig. 11 is a diagram showing the processing flow relating to time counting according to this embodiment.

[0091] (Step S501) The time counting unit 221 of the control unit 2 determines whether or not a 1 Hz interrupt signal has occurred. If a 1 Hz interrupt signal has occurred (step S501, YES), proceed to step S502. If a 1 Hz interrupt signal has not occurred (step S501, NO), continue with step S501.

[0092] (Step S502) The time counting unit 221 adds one second to the time (internal time) that it holds.

[0093] (Step S503) The time counting unit 221 notifies the control unit 1 of a time update. The event receiving unit 121 of the control unit 1 receives the time update notification (event) from the control unit 2.

[0094] (Step S504) The display update determination unit 123 of the control unit 1 determines whether or not the first standby operation time or the second standby operation time is in progress. If the first standby operation time or the second standby operation time is in progress (step S504, YES), the process proceeds to step S505. On the other hand, if the first standby operation time or the second standby operation time is not in progress (step S504, NO), the process proceeds to step S506.

[0095] (Step S505) The event holding unit 122 of the control unit 1 holds the event "time update notification" accepted by the event acceptance unit 121. Specifically, the event "time update notification" is registered in the held event information. Thereafter, when the second standby operation time period ends, it is determined in step S306 of FIG. 9 that there is a held event, and the process proceeds to step S307, where the process proceeds to step S506 of FIG. 11 to execute the held notification-event process, which is the time update notification.

[0096] (Step S506) The display update determination unit 123 determines whether the event "time update notification" received by the event reception unit 121 requires updating of the display on the liquid crystal panel 301. If it is determined that updating of the display on the liquid crystal panel 301 is required, the process proceeds to step S507. For example, if the current display is displaying the time, it is determined that updating of the display on the liquid crystal panel 301 is required. On the other hand, if it is determined that updating of the display on the liquid crystal panel 301 is not required, the process in FIG. 11 ends. For example, if the current display does not include a time display, it is determined that updating of the display on the liquid crystal panel 301 is not required. (Step S507) The image data output control unit 124 of the control unit 1 executes the display update process (FIG. 10) for the event "notification of time update" for which it is determined that the display on the liquid crystal panel 301 needs to be updated.

[0097] [Button operation process flow] The processing flow relating to button operations will be described with reference to Fig. 12. Fig. 12 is a diagram showing the processing flow relating to button operations according to this embodiment.

[0098] (Step S601) The control unit 2 determines whether the button 30 has been pressed (whether the button 30 has been operated). If it is determined that the button 30 has been pressed, the process proceeds to step S602. On the other hand, if it is not determined that the button 30 has been pressed, the process continues to step S601.

[0099] (Step S602) Control unit 2 determines whether control unit 1 is powered on. If control unit 1 is powered on, proceed to step S604. On the other hand, if control unit 1 is not powered on, proceed to step S603.

[0100] (Step S603) The control unit 2 turns on the power supply of the control unit 1.

[0101] (Step S604) The control unit 2 notifies the control unit 1 that the button 30 has been pressed and information identifying the pressed button 30. The event receiving unit 121 of the control unit 1 receives the notification (event) of the button operation from the control unit 2.

[0102] (Step S605) The display update determination unit 123 of the control unit 1 determines whether or not the first standby operation time or the second standby operation time is in progress. If the first standby operation time or the second standby operation time is in progress (YES in step S605), the process proceeds to step S606. On the other hand, if the first standby operation time or the second standby operation time is not in progress (NO in step S605), the process proceeds to step S607.

[0103] (Step S606) The event reserving unit 122 of the control unit 1 reserves the event "notification of button operation" accepted by the event accepting unit 121. Specifically, the event "notification of button operation" is registered in the reserved event information. Thereafter, when the second standby operation time period has ended, it is determined in step S306 of FIG. 9 that there is a reserved event, and the process proceeds to step S307, where the process proceeds to step S607 of FIG. 12 to execute the reserved notification-event process, which is the notification of button operation.

[0104] (Step S607) The control unit 1 executes a predetermined button process for each operated button indicated by the event "notification of button operation."

[0105] (Step S608) The display update determination unit 123 of the control unit 1 determines whether the event "notification of button operation" received by the event reception unit 121 requires updating of the display on the liquid crystal panel 301. If it is determined that updating of the display on the liquid crystal panel 301 is required, the process proceeds to step S609. For example, in the case of a button operation to switch the display mode, it is determined that updating of the display on the liquid crystal panel 301 is required. On the other hand, if it is determined that updating of the display on the liquid crystal panel 301 is not required, the process of FIG. 12 ends. For example, in the case of a button operation to start turning on the backlight illumination, it is determined that updating of the display on the liquid crystal panel 301 is not required.

[0106] (Step S609) The image data output control unit 124 of the control unit 1 executes the display update process (FIG. 10) for the event "notification of button operation" for which it is determined that the display on the liquid crystal panel 301 needs to be updated.

[0107] [Processing flow for stopwatch (STW) timing] The process flow relating to timekeeping by the stopwatch will be described with reference to Fig. 13. Fig. 13 is a diagram showing the process flow relating to timekeeping by the stopwatch according to this embodiment.

[0108] (Step S701) The STW timing unit 222 of the control unit 2 determines whether the button 30 (STW start button 30) that instructs the start of the stopwatch has been pressed (whether the STW start button 30 has been operated). If it is determined that the STW start button 30 has been pressed, the process proceeds to step S702. On the other hand, if it is not determined that the STW start button 30 has been pressed, the process continues to step S701.

[0109] (Step S702) The STW timing unit 222 starts the 1 kHz timer.

[0110] (Step S703) The STW timing unit 222 notifies the control unit 1 of the start of the stopwatch. The event receiving unit 121 of the control unit 1 receives the notification (event) from the control unit 2 that the stopwatch has started.

[0111] (Step S704) The display update determination unit 123 of the control unit 1 determines whether or not the first standby operation time or the second standby operation time is in progress. If the first standby operation time or the second standby operation time is in progress (step S704, YES), the process proceeds to step S705. On the other hand, if the first standby operation time or the second standby operation time is not in progress (step S704, NO), the process proceeds to step S706.

[0112] (Step S705) The event reserving unit 122 of the control unit 1 reserves the event "notification of the start of the stopwatch" accepted by the event accepting unit 121. Specifically, the event "notification of the start of the stopwatch" is registered in the reserved event information. Thereafter, when the second standby operation time period ends, it is determined in step S306 of FIG. 9 that there is a reserved event, and the process proceeds to step S307, where the process proceeds to step S706 of FIG. 13 to execute the reserved notification-event process, which is the notification of the start of the stopwatch.

[0113] (Step S706) Display update determination unit 123 determines whether the event "notification of stopwatch start" received by event reception unit 121 requires updating of the display on liquid crystal panel 301. If it is determined that updating of the display on liquid crystal panel 301 is necessary, the process proceeds to step S707. For example, if there is an icon indicating the operation status of the stopwatch, it is determined that updating of the display on liquid crystal panel 301 is necessary. On the other hand, if it is determined that updating of the display on liquid crystal panel 301 is not necessary, the process proceeds to step S708. For example, if there is no icon indicating the operation status of the stopwatch and the measurement unit is one second, the next display update timing will be one second later, and therefore it is determined that updating of the display on liquid crystal panel 301 is not necessary.

[0114] (Step S707) The image data output control unit 124 of the control unit 1 executes display update processing (FIG. 10) for the event "notification of the start of the stopwatch" for which it has been determined that updating of the display on the liquid crystal panel 301 is necessary. As a result, information indicating the start of measurement by the stopwatch is displayed on the liquid crystal panel 301.

[0115] (Step S708) The STW timing unit 222 of the control unit 2 determines whether or not it is 10 Hz timing using the 1 kHz timer. If it is determined that it is 10 Hz timing, proceed to step S709. On the other hand, if it is not determined that it is 10 Hz timing, continue with step S708.

[0116] (Step S709) The STW timing unit 222 adds 0.1 seconds to the stopwatch time (STW time) that it holds.

[0117] (Step S710) The STW timer unit 222 notifies the control unit 1 of an update of the display of the STW time (adding 0.1 seconds to the STW time). The event receiving unit 121 of the control unit 1 receives the notification (event) of the update of the display of the STW time from the control unit 2.

[0118] (Step S711) The display update determination unit 123 of the control unit 1 determines whether or not the first standby operation time or the second standby operation time is in progress. If the first standby operation time or the second standby operation time is in progress (step S711, YES), the process proceeds to step S712. On the other hand, if the first standby operation time or the second standby operation time is not in progress (step S711, NO), the process proceeds to step S713.

[0119] (Step S712) The event reserving unit 122 of the control unit 1 reserves the event "notification of STW time display update" accepted by the event accepting unit 121. Specifically, the event "notification of STW time display update" is registered in the reserved event information. Thereafter, when the second standby operation time period ends, it is determined in step S306 of FIG. 9 that there is a reserved event, and the process proceeds to step S307, where the process proceeds to step S713 of FIG. 13 to execute the reserved notification-event process, which is the notification of STW time display update.

[0120] (Step S713) The display update determination unit 123 determines whether the event "STW time display update notification" received by the event reception unit 121 requires updating of the display on the liquid crystal panel 301. If it is determined that updating of the display on the liquid crystal panel 301 is required, proceed to step S714. For example, if the measurement unit of the stopwatch is 0.1 seconds, it is determined that updating of the display on the liquid crystal panel 301 is required. On the other hand, if it is determined that updating of the display on the liquid crystal panel 301 is not required, return to step S708. For example, if the measurement unit of the stopwatch is 1 second and there is no change in the measurement value on the display (it has changed to 0.8 seconds), it is determined that updating of the display on the liquid crystal panel 301 is not required. (Step S714) The image data output control unit 124 of the control unit 1 executes the display update process (FIG. 10) for the event "Notification of STW time display update" for which it has been determined that updating the display on the liquid crystal panel 301 is necessary. This updates the stopwatch time displayed on the liquid crystal panel 301. After step S714, the process returns to step S708.

[0121] [Processing flow for resetting the stopwatch (STW)] The process flow relating to the stopwatch reset will be described with reference to Fig. 14. Fig. 14 is a diagram showing the process flow relating to the stopwatch reset according to this embodiment.

[0122] (Step S801) The STW timing unit 222 of the control unit 2 determines whether the button 30 (STW reset button 30) that instructs resetting the stopwatch has been pressed (whether the STW reset button 30 has been operated). If it is determined that the STW reset button 30 has been pressed, the process proceeds to step S802. On the other hand, if it is not determined that the STW reset button 30 has been pressed, the process continues to step S801.

[0123] (Step S802) The STW timer unit 222 resets the STW time to 0 (resets the 1 kHz counter circuit 204).

[0124] (Step S803) The STW timing unit 222 notifies the control unit 1 of the resetting of the stopwatch. The event receiving unit 121 of the control unit 1 receives the notification (event) of the resetting of the stopwatch from the control unit 2.

[0125] (Step S804) The display update determination unit 123 of the control unit 1 determines whether or not the first standby operation time or the second standby operation time is in progress. If the first standby operation time or the second standby operation time is in progress (step S804, YES), the process proceeds to step S805. On the other hand, if the first standby operation time or the second standby operation time is not in progress (step S804, NO), the process proceeds to step S806.

[0126] (Step S805) The event reserving unit 122 of the control unit 1 reserves the event "notification of stopwatch reset" accepted by the event accepting unit 121. Specifically, the event "notification of stopwatch reset" is registered in the reserved event information. Thereafter, when the second standby operation time period has ended, it is determined in step S306 of FIG. 9 that there is a reserved event, and the process proceeds to step S307, where the process proceeds to step S806 of FIG. 14 to execute the reserved notification-event process, which is the notification of stopwatch reset.

[0127] (Step S806) The display update determination unit 123 determines whether the event "notification of stopwatch reset" received by the event reception unit 121 requires updating of the display on the liquid crystal panel 301. If it is determined that updating of the display on the liquid crystal panel 301 is necessary, the process proceeds to step S807. For example, if the measurement value of the stopwatch has changed, it is determined that updating of the display on the liquid crystal panel 301 is necessary. On the other hand, if it is determined that updating of the display on the liquid crystal panel 301 is not necessary, the process in FIG. 14 ends. For example, if the measurement unit of the stopwatch is one second and the measurement value is less than one second, it is determined that updating of the display on the liquid crystal panel 301 is not necessary. (Step S807) The image data output control unit 124 of the control unit 1 executes the display update process (FIG. 10) for the event "notification of stopwatch reset" for which it has been determined that updating of the display on the liquid crystal panel 301 is necessary. As a result, the initial time of the stopwatch is displayed on the liquid crystal panel 301.

[0128] [Stopwatch (STW) Split Processing Flow] The processing flow relating to the stopwatch split will be described with reference to Fig. 15. Fig. 15 is a diagram showing the processing flow relating to the stopwatch split according to this embodiment.

[0129] (Step S901) The STW timing unit 222 of the control unit 2 determines whether the button 30 (STW split button 30) that instructs the stopwatch to split has been pressed (whether the STW split button 30 has been operated). If it is determined that the STW split button 30 has been pressed, the process proceeds to step S902. On the other hand, if it is not determined that the STW split button 30 has been pressed, the process continues with step S901.

[0130] (Step S902) The STW timer unit 222 acquires the STW time from the 1 kHz timer.

[0131] (Step S903) The STW timer unit 222 updates the STW time by less than 0.1 seconds.

[0132] (Step S904) The STW timing unit 222 notifies the control unit 1 of the split acquisition and the split time. The event receiving unit 121 of the control unit 1 receives the notification (event) of the split acquisition from the control unit 2.

[0133] (Step S905) The display update determination unit 123 of the control unit 1 determines whether or not the first standby operation time or the second standby operation time is in progress. If the first standby operation time or the second standby operation time is in progress (step S905, YES), the process proceeds to step S906. On the other hand, if the first standby operation time or the second standby operation time is not in progress (step S905, NO), the process proceeds to step S907.

[0134] (Step S906) The event reserving unit 122 of the control unit 1 reserves the event "notification of split acquisition" accepted by the event accepting unit 121. Specifically, the event "notification of split acquisition" is registered in the reserved event information. Thereafter, when the second standby operation time period ends, it is determined in step S306 of FIG. 9 that there is a reserved event, and the process proceeds to step S307, where the process proceeds to step S907 of FIG. 15 to execute the reserved notification-event process, which is the notification of stopwatch split acquisition.

[0135] (Step S907) The control unit 1 calculates the lap time from the split time acquired last time and the split time acquired this time.

[0136] (Step S908) The display update determination unit 123 determines whether the event "split acquisition notification" received by the event reception unit 121 requires updating of the display on the liquid crystal panel 301. If it is determined that updating of the display on the liquid crystal panel 301 is required, the process proceeds to step S909. For example, if the measurement unit of the stopwatch is 0.1 seconds, it is determined that updating of the display on the liquid crystal panel 301 is required. On the other hand, if it is determined that updating of the display on the liquid crystal panel 301 is not required, the process in FIG. 15 ends. For example, if the measurement unit of the stopwatch is 1 second and there is no change in the measurement value displayed (a change of less than 1 second, such as 0.8 seconds), it is determined that updating of the display on the liquid crystal panel 301 is not required. (Step S909) The image data output control unit 124 of the control unit 1 executes display update processing (FIG. 10) for the event "notification of split time acquisition" for which it has been determined that updating of the display on the liquid crystal panel 301 is necessary. As a result, the split time and lap time acquired this time by the stopwatch are displayed on the liquid crystal panel 301.

[0137] [Processing flow for stopwatch (STW) stop] The process flow relating to stopping the stopwatch will be described with reference to Fig. 16. Fig. 16 is a diagram showing the process flow relating to stopping the stopwatch according to this embodiment.

[0138] (Step S1001) The STW timing unit 222 of the control unit 2 determines whether the button 30 (STW stop button 30) that instructs stopping the stopwatch has been pressed (whether the STW stop button 30 has been operated). If it is determined that the STW stop button 30 has been pressed, the process proceeds to step S1002. On the other hand, if it is not determined that the STW stop button 30 has been pressed, the process continues to step S1001.

[0139] (Step S1002) The STW timing unit 222 stops the 1 kHz timer.

[0140] (Step S1003) The STW timer unit 222 acquires the STW time from the 1 kHz timer.

[0141] (Step S1004) The STW timer unit 222 updates the STW time by less than 0.1 seconds.

[0142] (Step S1005) The STW timing unit 222 notifies the control unit 1 of the stop of the stopwatch and the STW time (stop time) at the time of stop. The event receiving unit 121 of the control unit 1 receives the notification (event) of the stopwatch stop from the control unit 2.

[0143] (Step S1006) The display update determination unit 123 of the control unit 1 determines whether or not the first standby operation time or the second standby operation time is in progress. If the first standby operation time or the second standby operation time is in progress (step S1006, YES), the process proceeds to step S1007. On the other hand, if the first standby operation time or the second standby operation time is not in progress (step S1006, NO), the process proceeds to step S1008.

[0144] (Step S1007) The event reserving unit 122 of the control unit 1 reserves the event "notification of stopwatch stop" accepted by the event accepting unit 121. Specifically, the event "notification of stopwatch stop" is registered in the reserved event information. Thereafter, when the second standby operation time period has ended, it is determined in step S306 of FIG. 9 that there is a reserved event, and the process proceeds to step S307, where the process proceeds to step S1008 of FIG. 16 to execute the reserved notification-event process, which is the notification of stopwatch stop.

[0145] (Step S1008) The display update determination unit 123 determines whether the event "notification of stopwatch stop" received by the event reception unit 121 requires updating of the display on the liquid crystal panel 301. If it is determined that updating of the display on the liquid crystal panel 301 is necessary, the process proceeds to step S1009. For example, if the measurement value of the stopwatch has been updated, it is determined that updating of the display on the liquid crystal panel 301 is necessary. On the other hand, if it is determined that updating of the display on the liquid crystal panel 301 is not necessary, the process in FIG. 16 ends. For example, if the measurement unit of the stopwatch is one second and there is no change in the measurement value displayed (a change of less than one second, such as 0.8 seconds), it is determined that updating of the display on the liquid crystal panel 301 is not necessary. (Step S1009) The image data output control unit 124 of the control unit 1 executes display update processing (FIG. 10) for the event "notification of stopwatch stop" for which it has been determined that updating of the display on the liquid crystal panel 301 is necessary. As a result, the stop time is displayed on the liquid crystal panel 301.

[0146] According to this embodiment, an event accepted by the event acceptance unit 121 is put on hold during a fixed first standby operation time immediately before the polarity of the VCOM signal is inverted and a fixed second standby operation time immediately after the polarity of the VCOM signal is inverted, and after the first standby operation time and the second standby operation time have elapsed, it is determined whether the held event requires updating of the display on the liquid crystal panel 301, and image data for an event determined to require updating of the display on the liquid crystal panel 301 is written to the liquid crystal panel 301. Therefore, there is no need for processing to determine whether the period for transferring image data is included in the transfer standby period for inverting the polarity of the AC voltage applied to the liquid crystal panel 301, allowing for a simple software configuration.

[0147] According to this embodiment, the duty ratio of the positive and negative periods of the AC voltage of the VCOM signal can be set to 50%, which contributes to maintaining the reliability of the liquid crystal of the liquid crystal panel 301.

[0148] According to this embodiment, by setting the polarity inversion period of the VCOM signal to a value that is a non-integer multiple of the fixed period at which display updates of the liquid crystal panel 301 occur due to a specific function of the time measurement device 1, it is possible to reduce the possibility that the timing of polarity inversion of the AC voltage applied to the liquid crystal panel 301 will overlap with the timing of display updates, i.e., the timing of image data output, when the event is an event caused by something external to the time measurement device 1 (for example, a button operation by the user).

[0149] The time measurement device 1 may be provided in a digital electronic clock, a combination clock having a digital display function and a hands display function, a stopwatch, or a timer.

[0150] In addition, in the configuration example of Figure 1, the functions of the time measurement device 1 are divided into the first control device 100 and the second control device 200, but the functions of the time measurement device 1 may be realized by one control device (one CPU) or by two or more control devices (two or more CPUs). In addition, in the configuration example of Figure 1, the voltage conversion circuit 41 converts the voltage of the power supply 40 into the operating voltage of the first control device 100, the second control device 200, and the display module 300, but the first control device 100 and the second control device 200 may be directly driven by the power supply (battery) 40, and only the display module 300 may be converted into an operating voltage by the voltage conversion circuit 41. In addition, in the configuration example of Figure 1, when the power of control unit 1 is turned off, control unit 1 is configured to notify control unit 2 of the current state (mode, etc.), but it is also possible to add a non-volatile memory to first control device 100 and have control unit 1 store the current state (mode, etc.) in the non-volatile memory.

[0151] Furthermore, a computer program for implementing the functions of the time measurement device described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read and executed by a computer system. Note that the term "computer system" may include hardware such as an OS and peripheral devices. In addition, "computer-readable recording medium" refers to writable non-volatile memory such as a flexible disk, optical magnetic disk, ROM, or flash memory, portable media such as a DVD (Digital Versatile Disc), or a storage device such as a hard disk built into a computer system.

[0152] Furthermore, the term "computer-readable recording medium" also includes those that retain a program for a certain period of time, such as volatile memory (e.g., DRAM (Dynamic Random Access Memory)) within a computer system that serves as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has the function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may also be a program for implementing some of the functions described above, or may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already stored in the computer system.

[0153] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0154] 1...Time measurement device, 10...Vibrator, 20...Crystal oscillator, 100...First control device, 200...Second control device, 300...Display module, 30...Button, 40...Power supply, 41...Voltage conversion circuit, 42...Power supply control circuit, 43...Display power supply control circuit, 101, 201...Oscillation circuit, 102, 202...Frequency divider circuit, 103, 203...Timer circuit, 104...Wireless communication circuit, 105...First control unit, 106, 206... ROM, 107, 207...RAM, 108, 109, 209...communication circuits, 110, 208...input circuits, 111, 210...output circuits, 121...event reception unit, 122...event reservation unit, 123...display update determination unit, 124...image data output control unit, 125...polarity control unit, 204...1 kHz counter circuit, 205...second control unit, 221...time measuring unit, 222...stopwatch (STW) measuring unit

Claims

1. A time measurement device having a time measurement function and displaying an image on a liquid crystal panel by writing image data on the liquid crystal panel, a polarity control unit that inverts the polarity of the AC voltage applied to the liquid crystal panel at a constant polarity inversion period; an event reception unit that receives an event that may cause an update of the display on the liquid crystal panel; an event holding unit that holds the event accepted by the event accepting unit during a period of a first standby operation period immediately before the polarity of the AC voltage is reversed and a second standby operation period immediately after the polarity of the AC voltage is reversed; a display update determination unit that determines whether the event being held back requires updating of the display on the liquid crystal panel after the first standby operation time and the second standby operation time have elapsed; an image data output control unit that writes image data of the event for which it has been determined that updating of the display on the liquid crystal panel is necessary, to the liquid crystal panel; the first standby operation time includes one unit of time for writing image data to the liquid crystal panel and an image data writing inhibition time immediately before the polarity of the AC voltage is reversed, the second standby operation time includes an image data writing inhibition time immediately after the polarity of the AC voltage is reversed; Time measuring device.

2. the image data output control unit writes, to the liquid crystal panel after the second standby operation time has elapsed, a portion of the image data of the event for which it has been determined that updating of the display on the liquid crystal panel is necessary, the portion of the image data that has not been completely written to the liquid crystal panel before the first standby operation time has elapsed. The time measurement device according to claim 1 .

3. Among the image data of the event for which it is determined that updating of the display on the liquid crystal panel is necessary, a portion of the image data that is completed to be written to the liquid crystal panel before the end of the first standby operation time period and a portion of the image data that is to be written to the liquid crystal panel after the elapse of the second standby operation time period are written at different addresses on the liquid crystal panel. The time measurement device according to claim 2 .

4. Among the image data of the event for which it is determined that updating of the display on the liquid crystal panel is necessary, a portion of the image data that will be completely written to the liquid crystal panel before the end of the first standby operation time period and a portion of the image data that will be written to the liquid crystal panel after the elapse of the second standby operation time period are displayed in different portions on the display area of ​​the liquid crystal panel. The time measurement device according to claim 2 .

5. the event is a request for a predetermined process within the time measurement device that occurs after the time measurement device receives a communication from a control unit having a predetermined control function within the time measurement device; The time measurement device according to claim 1 .

6. the event is a request for a predetermined process that is initiated by a hardware interrupt that occurs within the time measurement device to a control unit having a predetermined control function within the time measurement device; The time measurement device according to claim 1 .

7. the event is a request to update the display of the time measured within the time measurement device; The time measurement device according to claim 1 .

8. the event is a request to update the display of the time measured within the timing device; The time measurement device according to claim 1 .

9. the polarity inversion period is a non-integer multiple of a fixed period at which a display update of the liquid crystal panel occurs due to a specific function of the time measurement device, The time measurement device according to claim 1 .

10. the event is a request for a predetermined process for each operated button after the operation of a button provided in the timing device is accepted; The time measurement device according to claim 9.

11. the event is a request for a predetermined process within the time measurement device that occurs after the time measurement device receives communication from an external device within the time measurement device; The time measurement device according to claim 9.

12. The event is a request for a predetermined process that occurs in response to a change in an internal or external state of the time measurement device. The time measurement device according to claim 9.

13. writing image data to the liquid crystal panel is performed by transmitting an address indicating a display position on the liquid crystal panel, transmitting image data, and transmitting a write command once or repeatedly performing the same a plurality of times as one write operation, and by continuously performing the same write operation a plurality of times, image data to be simultaneously displayed in the display area of ​​the liquid crystal panel is written; When the timing for reversing the polarity of the AC voltage comes during the multiple consecutive executions of the single write operation, the single write operation currently being executed is completed, and the remaining one or more single write operations are executed after the second standby operation time period has elapsed. The time measurement device according to claim 1 .

14. The time measuring device is provided in a digital electronic clock, a combination clock having a digital display function and a pointer display function, a stopwatch, or a timer. The time measurement device according to claim 1 .

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