WO2022168200A1 - Display device - Google Patents

Display device Download PDF

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Publication number
WO2022168200A1
WO2022168200A1 PCT/JP2021/003912 JP2021003912W WO2022168200A1 WO 2022168200 A1 WO2022168200 A1 WO 2022168200A1 JP 2021003912 W JP2021003912 W JP 2021003912W WO 2022168200 A1 WO2022168200 A1 WO 2022168200A1
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WO
WIPO (PCT)
Prior art keywords
power
operating
display
converters
power converter
Prior art date
Application number
PCT/JP2021/003912
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French (fr)
Japanese (ja)
Inventor
尚司 大塚
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to PCT/JP2021/003912 priority Critical patent/WO2022168200A1/en
Priority to JP2022579212A priority patent/JP7450774B2/en
Publication of WO2022168200A1 publication Critical patent/WO2022168200A1/en

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators

Definitions

  • the present disclosure relates to display devices.
  • a display device which includes a display for displaying images and a power supply circuit for outputting power necessary for displaying the images to the display.
  • the power supply circuit converts commercial AC power into DC power, and outputs the DC power obtained by conversion to the display.
  • a display device In a display device, power is consumed not only in the display unit but also in the power supply circuit. Therefore, the power supply circuit generates heat as the display device operates, and the larger the amount of heat generated by the power supply circuit, the more likely the display device is to malfunction. Therefore, a power supply circuit in which heat generation is suppressed is desired.
  • An object of the present disclosure is to provide a display device in which heat generation in a power supply circuit is suppressed more than before.
  • the display device is a display device having a plurality of display units forming a display screen on which an image is displayed, wherein the amount of power required to display the image on the display screen varies;
  • a power supply circuit having a plurality of power converters connected in parallel to a power supply unit that supplies AC power, each of the power converters converting the AC power into DC power;
  • a required power value representing the magnitude of the power required to display the image on the display screen is obtained, and based on the obtained required power value, the smaller the required power value, the more the plurality of power supply circuits constituting the power supply circuit.
  • a control device that controls the number of units in a non-operating state that cuts off the a repeater that distributes the DC power output by the operating power converter to a plurality of the display units that constitute the display; Prepare.
  • the smaller the required power value the smaller the number of operating power converters due to the number control. Therefore, when the required power is reduced, the output power of the operating power converter is less likely to decrease, so the power conversion efficiency of the operating power converter is less likely to decrease. That is, even if the number of active power converters is reduced, power loss in the active power converters is less likely to increase.
  • the number of non-operating power converters increases as the required power value becomes smaller, and heat generation due to power consumption is suppressed in the non-operating power converters. As a result, heat generation in the power supply circuit is suppressed more than before.
  • FIG. 1 is a conceptual diagram showing the appearance of a display device according to Embodiment 1.
  • FIG. 1 is a conceptual diagram showing the configuration of a display device according to Embodiment 1;
  • FIG. Flowchart of heat generation suppression processing according to the first embodiment The conceptual diagram which shows the structure of the 1st power converter which concerns on Embodiment 2.
  • FIG. 2 is a conceptual diagram showing the configuration of a display device according to Embodiment 2;
  • FIG. 2 is a conceptual diagram showing the configuration of a control device according to Embodiment 2;
  • Flowchart of heat generation suppression processing according to the second embodiment Flowchart of heat generation suppression processing according to the third embodiment
  • the display device 800 As shown in FIG. 1, the display device 800 according to the present embodiment includes a display 100 having a display screen 100a on which an image is displayed, and a device storage box 710 containing devices for controlling the display 100. Prepare.
  • the display 100 is arranged separately from the equipment storage box 710 . Specifically, the display 100 is attached to the upper end portion of a support 720 erected on the ground, and the device housing box 710 is arranged beside the lower end portion of the support 720 .
  • the display device 100 and the device housing box 710 are connected by power wiring 730 for transmitting power necessary for displaying images from the device housing box 710 to the display device 100, and video data representing the content of the video from the device housing box 710 to the display device. 100 are connected by a wiring group including a data wiring 740 for transmission to 100 .
  • the display device 800 is installed near a road outdoors.
  • the display screen 100a visually provides the driver of the vehicle traveling on the road with road information such as road congestion, accident occurrence, traffic regulation, and weather in the form of an image.
  • the display 100 has a first display unit 110, a second display unit 120, a third display unit 130, and a fourth display unit 140, each displaying an image.
  • the four units of the first display unit 110 to the fourth display unit 140 are combined in a matrix, specifically in a matrix of 2 rows and 2 columns, to form a single display screen 100a as a whole.
  • Each of the first display unit 110 to the fourth display unit 140 has a plurality of light emitting devices that emit visible light, and a circuit board on which the plurality of light emitting devices are mounted.
  • the plurality of light-emitting devices are two-dimensionally distributed and arranged on the surface of the circuit board.
  • Each light emitting device has a red LED (Light Emitting Diode) that emits red light, a green LED that emits green light, and a blue LED that emits blue light.
  • the display device 800 includes a power supply unit 200 configured by a distribution board that outputs commercial AC power, and a power supply circuit 300 that converts the AC power supplied from the power supply unit 200 into DC power. Prepare.
  • the display device 100 displays an image on the display screen 100 a based on the DC power obtained by conversion by the power supply circuit 300 .
  • the power supply circuit 300 has a first power converter 310 , a second power converter 320 , a third power converter 330 and a fourth power converter 340 connected in parallel to the power supply section 200 .
  • Each of the first power converter 310 to the fourth power converter 340 converts AC power supplied from the power supply unit 200 into DC power, and outputs the DC power obtained by the conversion.
  • the power supply circuit 300 consumes power for power conversion from AC power to DC power. Therefore, the power supply circuit 300 generates heat, which causes the display device 800 to malfunction. Therefore, in order to reduce the probability of failure occurring in the display device 800, a configuration in which the power supply circuit 300 hardly generates heat is desired.
  • the display device 900 As shown in FIG. 9, in the display device 900 according to the comparative embodiment, four display units 110 to 140 and four power converters 310 to 440 are provided. , are associated one-to-one.
  • the first display unit 110 receives power exclusively from the first power converter 310 .
  • the second display unit 120 is exclusively powered by the second power converter 320 .
  • the third display unit 130 is exclusively powered by the third power converter 330 .
  • the fourth display unit 140 is exclusively powered by the fourth power converter 340 .
  • the control device 910 in order to display an image on the display screen 100a, the control device 910 according to the comparative embodiment always operates all of the first power converter 310 to the fourth power converter 340 in parallel. Since each of the first power converter 310 to the fourth power converter 340 consumes power for power conversion during operation, heat is generated in the power supply circuit 300 .
  • the amount of power required to display an image on the display screen 100a temporally changes according to the total value of luminance within the plane of the display screen 100a. Therefore, when the power required to display an image on the display screen 100a is reduced, the total output power of the power supply circuit 300 is reduced.
  • each of the first power converter 310 to the fourth power converter 340 has a characteristic that the lower the output power, the lower the power conversion efficiency.
  • the power conversion efficiency of a power converter refers to the value obtained by dividing the output power output by the power converter by the input power input to the power converter.
  • the power change efficiency of the power converter is ⁇ [%]
  • 100 ⁇ [%] represents the power consumed by the power converter, that is, the rate of power loss in the power conversion. The greater the power loss, the greater the heat generation.
  • the heat generated by the power supply circuit 300 causes failure of the power supply circuit 300 itself and failure of the equipment housed together with the power supply circuit 300 in the equipment housing box 710 shown in FIG.
  • this embodiment adopts a configuration in which the power supply circuit 300 is less likely to generate heat.
  • the configuration of this embodiment will be specifically described.
  • a display device 800 includes a switch group 400 connected between a power supply circuit 300 and a power supply section 200, and a switch group 400 connected between the power supply circuit 300 and a display device 100. and a controller 600 that controls the display 100 , the power supply circuit 300 , the group of switches 400 , and the repeater 500 .
  • the power supply unit 200, the power supply circuit 300, the switch group 400, the repeater 500, and the control device 600 are housed in the equipment housing box 710 shown in FIG.
  • the switch group 400 includes a first switch 410 interposed between the first power converter 310 and the power supply section 200 and a second switch 420 interposed between the second power converter 320 and the power supply section 200. , a third switch 430 interposed between the third power converter 330 and the power supply section 200 , and a fourth switch 440 interposed between the fourth power converter 340 and the power supply section 200 .
  • the first switch 410 can be switched between a conductive state in which the first power converter 310 is connected to the power supply unit 200 and a cutoff state in which the first power converter 310 is cut off from the power supply unit 200 .
  • Second switch 420 can be switched between a conductive state in which second power converter 320 is connected to power supply unit 200 and a cutoff state in which second power converter 320 is cut off from power supply unit 200 .
  • Third switch 430 can be switched between a conductive state in which third power converter 330 is connected to power supply unit 200 and a cutoff state in which third power converter 330 is cut off from power supply unit 200 .
  • the fourth switch 440 can be switched between a conductive state in which the fourth power converter 340 is connected to the power supply unit 200 and a cutoff state in which the fourth power converter 340 is cut off from the power supply unit 200 .
  • the control device 600 obtains a required power value WX representing the amount of power required to display an image on the display screen 100a.
  • the number of power converters 310 to the fourth power converter 340 is controlled to reduce the number of those to be operated (hereinafter referred to as "operating power converters").
  • the control device 600 controls the operating power converters to an operating state in which DC power is output, while controlling the operating power converters among the first power converter 310 to the fourth power converter 340. Controls other devices (hereinafter referred to as non-operating power converters) to a non-operating state that cuts off the output of DC power.
  • non-operating power converters other devices
  • control device 600 controls the first switch 410 to the fourth switch 440, which are provided for the operating power converters, to be in a conductive state, while the non-operating power converters are It is realized by controlling the provided one to the cut-off state.
  • the repeater 500 distributes the DC power output by the operating power converter of the power supply circuit 300 from the first display unit 110 to the fourth display unit 140 .
  • the repeater 500 synthesizes the DC power output from all the operating power converters, and outputs the synthesized DC power from the first display unit 110. distributed to the fourth display unit 140;
  • synthesis means addition.
  • repeater 500 distributes the DC power output by its active power converter from first display unit 110 to fourth display unit 140 .
  • the repeater 500 also has a voltage drop section 510 that drops the DC voltage output from the operating power converter of the power supply circuit 300 for stabilization.
  • the magnitude of the voltage dropped by voltage drop unit 510 may be variably adjusted under the control of control device 600 .
  • the required power value described above is a value that allows for a voltage drop in the voltage drop section 510 .
  • the control device 600 also controls the display device 100 . This point will be described below. Video data representing the content of the video to be displayed on the display device 100 is transmitted from an external video distribution center VD to the control device 600 .
  • the control device 600 has a buffer memory 610 that temporarily accumulates video data transmitted from the video distribution center DV every moment.
  • the buffer memory 610 has a storage capacity capable of writing video data for at least two frames. Note that a frame is one frame of a still image forming a moving image representing video.
  • the control device 600 reads from the buffer memory 610 the video data for one frame already written to the buffer memory 610 and transmits the read video data to the display device 100 through the data wiring 740 . In parallel with reading the video data from the buffer memory 610 , the control device 600 writes the video data of the next frame obtained from the video distribution center DV to the buffer memory 610 .
  • the control device 600 performs the above-described number control in parallel with transmission of video data to the display device 100 . Specifically, each time one frame of video data is acquired from the video distribution center DV, the control device 600 uses the one frame of video data to determine the brightness of the display screen 100a in that frame. Find the total value.
  • the "total value of luminance” means a value obtained by adding the luminance of each pixel constituting the display screen 100a for all pixels. Note that one light-emitting device constitutes one pixel.
  • the control device 600 obtains a required power value WX representing the magnitude of power required to display an image on the display screen 100a based on the calculated total luminance value. Then, the control device 600 performs the above-described number control using the obtained required power value WX.
  • the heat generation suppression process for suppressing the heat generation of the power supply circuit 300 by controlling the number of units will be described below.
  • control device 600 first obtains the required power value WX using the video data acquired from the video distribution center DV as described above (step S11).
  • step S12 when the required power value WX is equal to or less than a first threshold value W1 predetermined as the upper limit value of the power that can be output from the first power converter 310 (step S12; YES), the control device 600 1
  • the power converter 310 is operated as an active power converter (step S13).
  • control device 600 stops the second power converter 320 to the fourth power converter 340 as non-operating power converters. Specifically, the control device 600 controls the first switch 410 to be conductive, and controls the second switch 420 to the fourth switch 440 to be disconnected.
  • the repeater 500 appropriately drops the output voltage of the first power converter 310 in the voltage drop section 510 and distributes it evenly from the first display unit 110 to the fourth display unit 140 .
  • the controller 600 determines that the required power value WX is greater than the first threshold value W1 (step S12; NO), and that the total of the first power converter 310 and the second power converter 320 can output If it is equal to or less than the second threshold value W2 predetermined as the upper limit of power (step S14; YES), the first power converter 310 and the second power converter 320 are operated as operating power converters (step S15 ).
  • control device 600 stops the third power converter 330 and the fourth power converter 340 as non-operating power converters. Specifically, the control device 600 controls the first switch 410 and the second switch 420 to be conductive, and controls the third switch 430 and the fourth switch 440 to be disconnected.
  • the repeater 500 synthesizes the output voltages of the first power converter 310 and the second power converter 320 , appropriately lowers the voltage in the voltage drop section 510 , and outputs the voltage from the first display unit 110 to the fourth display. Distribute evenly among units 140 .
  • control device 600 determines that required electric power value WX is greater than second threshold value W2 (step S14; NO), and the total of three power converters 310 to 330 can output When it is equal to or less than the third threshold value W3 predetermined as the upper limit value of power (step S16; YES), the first power converter 310 to the third power converter 330 are operated as operating power converters (step S17 ).
  • control device 600 stops the fourth power converter 340 as a non-operating power converter. Specifically, the control device 600 controls the first switch 410 to the third switch 430 to be conductive, and controls the fourth switch 440 to be disconnected.
  • the repeater 500 synthesizes the output voltages of the first power converter 310 to the third power converter 330 , appropriately lowers the voltage in the voltage drop section 510 , and then outputs the voltage from the first display unit 110 to the fourth display. Distribute evenly among units 140 .
  • step S16 when the required power value WX is greater than the third threshold value W3 (step S16; NO), the control device 600 sets all of the first power converter 310 to the fourth power converter 340 to the operating power converter. (step S18). Specifically, the control device 600 controls the first switch 410 to the fourth switch 440 to be conductive.
  • the repeater 500 synthesizes the output voltages of the first power converter 310 to the fourth power converter 340 , appropriately lowers the voltage in the voltage drop section 510 , and then outputs the voltage from the first display unit 110 to the fourth display. Distribute evenly among units 140 .
  • the processing from steps S11 to S18 described above represents number control in which the number of operating power converters is decreased as the required power value WX is smaller.
  • step S19; YES when the control device 600 ends the display of the image on the display device 100 (step S19; YES), the heat generation suppression process ends. On the other hand, when the control device 600 continues to display the image on the display device 100 (step S19; NO), the control device 600 returns to step S11 again and repeats the number control.
  • the repetition frequency of the number control is equal to the frame rate of the video on the display screen 100a.
  • the frame rate means the number of still images displayed per second, that is, the number of frames per second.
  • the frame rate is 0.5 Hz or more and 5 Hz or less, specifically 1 Hz or more and 2 Hz or less.
  • each of the first power converter 310 to the fourth power converter 340 exhibits a power conversion efficiency of 95% when the output power is 100W, and a power conversion efficiency of 90% when the output power is 50W.
  • the first threshold W1 is 150 [W]
  • the second threshold W2 is 250 [W]
  • the required power value WX is 200 [W].
  • step S15 the first power converter 310 and the second power converter 320 are operated as operating power converters. Since the first power converter 310 and the second power converter 320 equally share the required power value WX of 200 [W], each power converter requires an output power of 100 [W]. be.
  • the power conversion efficiency is 95% when the output power is 100 W, so the power loss in each of first power converter 310 and second power converter 320 is (100/0.95) ⁇ 0.05 ⁇ 5.3 [W]. That is, to obtain 100 W of output power, approximately 105.3 [W] of input power is required, of which 5.3 [W] is consumed.
  • the four power converters 310 to 340 equally share the required power value WX of 200 [W], so the output per unit Electric power is suppressed to 50 [W]. Then, as described above, since the power conversion efficiency is 90% when the output power is 50 W, the power loss in each of the first power converter 310 to the fourth power converter 340 is (50/0.9) ⁇ 0 .1 ⁇ 5.6 [W].
  • the power loss of the power supply circuit 300 as a whole can be suppressed to less than half of that in the comparative embodiment. Therefore, heat generation of the power supply circuit 300 is suppressed more than in the case of the comparison mode.
  • Each of the first power converter 310 to the fourth power converter 340 has a characteristic that the lower the output power, the lower the power conversion efficiency. This means that the power conversion efficiency in the converter is less likely to decrease. That is, even if the number of operating power converters is reduced as the required power value WX decreases, power loss in the operating power converters is less likely to increase.
  • the number of non-operating power converters increases as the required power value WX decreases, and the heat generated by the non-operating power converters due to power consumption is suppressed.
  • heat generation in the power supply circuit 300 is suppressed more than in the case of the comparative embodiment.
  • the second power converter 320 to the fourth power converter 340 are not always operated, but are selectively operated. Therefore, compared to the comparative form in which the four power converters 310 to 340 are always operated, the period during which each of the second power converter 320 to the fourth power converter 340 is operated is reduced. be done. As a result, the life of the power supply circuit 300 and thus the life of the display device 800 can be extended.
  • the power conversion characteristics of the first power converter 310 to the fourth power converter 340 may be the same. That is, the dependence of the power conversion efficiency on the output power may be substantially the same in each of the first power converter 310 to the fourth power converter 340 . Since the first to fourth power converters 310 to 340 having substantially the same power conversion characteristics can be used, the power supply circuit 300 can be easily manufactured and easily managed.
  • switching between the operating state and the non-operating state of each of the first power converter 310 to the fourth power converter 340 is realized using the switch group 400 .
  • Switching between the operating state and the non-operating state may be performed by controlling each of the first power converter 310 to the fourth power converter 340 without using the switch group 400 .
  • a specific example will be described below.
  • the configuration of the first power converter 310 is illustrated in FIG.
  • the first power converter 310 includes a primary circuit 351 to which AC power is input from the power supply unit 200 shown in FIG. 2, a secondary circuit 352 to output DC power to the repeater 500 shown in FIG. It is a switched-mode power supply having a transformer 353 interposed between a secondary circuit 351 and a secondary circuit 352 and a switching element 354 connected to the transformer 353 .
  • the primary circuit 351 includes a smoothing capacitor 351a for smoothing the voltage.
  • the second power converter 320 to the fourth power converter 340 shown in FIG. 2 are switching power supplies having the same configuration as that shown in FIG.
  • FIG. 5 shows the configuration of a display device 800 according to this embodiment.
  • the display device 800 according to this embodiment does not include the switch group 400 shown in FIG.
  • the control device 600 puts the non-operating power converters in the non-operating state by causing the switching elements 354 of the non-operating power converters to stop switching operations in the number control.
  • the control device 600 puts the operating power converter into the operating state by causing the switching element 354 of the operating power converter to perform a switching operation.
  • the switch group 400 shown in FIG. 2 is unnecessary, so the number of parts constituting the display device 800 can be reduced.
  • the switching operation of the switching element 354 shown in FIG. be. Therefore, when the non-operating power converter is switched to the operating power converter, there is no need to wait for the smoothing capacitor 351a to be charged, so the output of the DC power from the secondary circuit 352 starts immediately. Therefore, according to the present embodiment, even when the video frame rate is high, the supply of DC power from the operating power converter that has been switched from the non-operating state to the operating state is less likely to be interrupted.
  • the control device 600 includes a memory storing operation history data 620 for managing the frequency of operation of each of the first power converter 310 to the fourth power converter 340. 630.
  • the operation history data 620 represents the cumulative operating period length, which is the cumulative value of the period length during which the power converter is in the operating state, for each of the first power converter 310 to the fourth power converter 340 .
  • FIG. 7 shows a flowchart of heat generation suppression processing according to this embodiment. Only differences between the heat generation suppression process shown in FIG. 7 and the heat generation suppression process shown in FIG. 3 will be described below.
  • the control device 600 determines that the required power value WX is equal to or less than the first threshold value W1 predetermined as the upper limit value of the power that can be output by one operating power converter (step S12; YES).
  • step S12 the first threshold value W1 predetermined as the upper limit value of the power that can be output by one operating power converter.
  • the control device 600 uses the operation history data 620, under the condition that the variation in the dispersion of the operation period length among the four power converters 310 to 340 is minimal, Select one as the active power converter. Specifically, the power converter with the shortest cumulative operating period length is selected as the operating power converter among the four units. Then, the selected operating power converter is controlled to be in the operating state, and the remaining three non-operating power converters are controlled to be in the non-operating state (step S21).
  • control device 600 sets the required power value WX to be greater than the second threshold value W2 (step S14; NO), and preliminarily sets the upper limit value of the power that can be output by the three operating power converters. If it is equal to or less than the determined third threshold value W3 (step S16; YES), first, using the operation history data 620, the operation period length between the four units of the first power converter 310 to the fourth power converter 340 3 out of the 4 are selected as active power converters under the condition that the change in the variance of is minimal. Then, the selected three operating power converters are controlled to be in the operating state, and the remaining one non-operating power converter is controlled to be in the non-operating state (step S23).
  • control device 600 updates the operation history data 620 (step S24) after step S21, S22, S23, or S18. That is, the control device 600 according to this embodiment updates the operation history data 620 each time the number of machines is controlled. Therefore, the latest operation history data 620 can be used in the next number control.
  • step S24 the control device 600 according to the present embodiment refers to the updated operation history data 620, and the operation period length of at least one of the first power converter 310 to the fourth power converter 340 is It is checked whether or not a predetermined reference period length has been exceeded. Then, when there is a power conversion device whose operating period length exceeds the reference period length, the control device 600 issues a warning to that effect to the outside.
  • exital specifically includes a terminal placed in a remote management center that manages the operation of the display device 800, a warning light attached to the display device 800, and other devices for informing maintenance personnel of warnings.
  • Means notification means specifically includes a terminal placed in a remote management center that manages the operation of the display device 800, a warning light attached to the display device 800, and other devices for informing maintenance personnel of warnings.
  • Means notification means specifically includes a terminal placed in a remote management center that manages the operation of the display device 800, a warning light attached to the display device 800, and other devices for informing maintenance personnel of warnings.
  • control device 600 proceeds to step S19 described above.
  • the upper limit value of the brightness of the display screen 100a may be changed according to the time zone of the day. A specific example will be described below.
  • the control device 600 first determines whether or not a brightness change time predetermined as a time to change the brightness of the display screen 100a has arrived (step S31).
  • the brightness change times are 5:00 am, 10:00 am, 3:00 pm, and 7:00 pm.
  • “early morning” refers to the period from 5:00 am to 10:00 am.
  • “Daytime” refers to the period from 10:00 am to 3:00 pm.
  • “Evening” refers to the period from 3:00 pm to 7:00 pm.
  • “Night” refers to the period from 7:00 pm to 5:00 am.
  • the illuminance of the sunlight is lower at night than in the daytime, so the contrast of the display screen 100a is increased and the display screen 100a is easier to see. Therefore, at night, the brightness of the display screen 100a may be lowered.
  • step S31 when nighttime arrives, that is, when 7:00 pm as the brightness change time arrives in step S31 (step S31; YES), the control device 600 sets the upper limit value of the brightness of all the pixels of the display screen 100a to , to a value that is 60% lower than the upper limit value for daytime (step S32).
  • control device 600 can set any brightness value represented by the video data under the condition that the instantaneous value of the brightness of each pixel is reduced by 60% compared to the daytime. is corrected to a value that is 60% lower than that in the daytime.
  • the display screen 100a is easier to see in the early morning and evening than in the daytime, the brightness of the display screen 100a can be suppressed.
  • step S31 when early morning or evening arrives, that is, when 5:00 am or 7:00 pm as the brightness change time arrives in step S31 (step S31; YES), the control device 600 controls all pixels of the display screen 100a. is changed to a value that is 40% lower than the upper limit value for daytime (step S32).
  • control device 600 can reduce the instantaneous value of the brightness of each pixel by 40% compared to the daytime.
  • the brightness value is corrected to a value that is 40% lower than that in the daytime.
  • control device 600 ends the display of the image on the display device 100 (step S19; YES)
  • the heat generation suppression process ends.
  • control device 600 continues to display the image on display 100 (step S19; NO)
  • control device 600 returns to step S31 and repeats the same processing.
  • the control device 600 changes the upper limit value of the brightness of the display screen 100a according to the time period of the day. As a result, the power consumption in the display device 100 can be reduced, and heat generation in the power supply circuit 300 can be further suppressed.
  • Embodiments 1-4 have been described above. Variations described below are also possible.
  • the display device 800 is installed near a road and displays road information. , advertisements, etc. may be displayed.
  • FIG. 1 illustrates a configuration in which the display 100 and the device housing box 710 are separated, but the display 100, the power supply unit 200, the power supply circuit 300, the switch group 400, the repeater 500, and the control device 600 may be contained within a common frame.
  • the frame rate of the moving image to be displayed on the display screen 100a was exemplified as the frame rate of the moving image to be displayed on the display screen 100a, but the values are not limited to these values.
  • the frame rate may be 24 Hz or higher, specifically 24 Hz, 30 Hz, 50 Hz, or 60 Hz.
  • the repetition frequency of the number control is equal to the frame rate of the moving image
  • the repetition frequency and the frame rate of the number control may not necessarily be equal.
  • the number control may be repeatedly performed at a repetition frequency expressed by f/n.
  • the configuration of the voltage drop unit 510 shown in FIG. 2 is not particularly limited.
  • the voltage drop unit 510 may be configured by one or more direct current/DC converters (DC to DC converters) or other voltage drop circuits including transformers.
  • DC to DC converters DC to DC converters
  • each voltage drop circuit can be made lighter than when the voltage drop section 510 is composed of a single voltage drop circuit.
  • a plurality of voltage drop circuits can be arranged separately. Therefore, it is possible to avoid concentration of the load of the voltage drop portion 510 on a narrow region. Therefore, the member supporting the voltage drop portion 510 does not need to be formed with high rigidity, so that the weight of the member supporting the voltage drop portion 510 can be reduced.
  • the repeater 500 does not have to include the voltage drop section 510 . That is, the repeater 500 may supply the direct-current voltage output from the power supply circuit 300 to the display device 100 as it is. When the repeater 500 does not include the voltage drop section 510, the weight of the repeater 500 can be reduced.
  • the light-emitting device included in the display 100 is a light-emitting diode was exemplified, but the light-emitting device may emit visible light from an element that produces organic electroluminescence.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
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  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

In a display device (800), a power supply circuit (300) comprises a plurality of power converters (310 to 340). Each of the power converters (310 to 340) converts alternating-current power into direct-current power. A control device (600) performs number control for finding a required power value indicating the magnitude of power required to display video, determining, on the basis of the found required power value, the number of operational power converters on the condition that the smaller the required power value, the lower the number of operational power converters to be operated among the plurality of power converters (310 to 340), bringing the determined number of operational power converters into an operational state in which direct-current power is outputted, and bringing non-operational power converters other than the operational power converters into a non-operational state in which the output of the direct-current power is stopped. A repeater (500) distributes the direct-current power outputted by the operational power converters among a plurality of display units (110 to 140) constituting a display (100).

Description

表示装置Display device
　本開示は、表示装置に関する。 The present disclosure relates to display devices.
　特許文献１に示されているように、映像を表示する表示器と、映像の表示に必要な電力を表示器に出力する電源回路とを備える表示装置が知られている。電源回路は、商用の交流電力を直流電力に変換し、変換して得られた直流電力を表示器に出力する。 As shown in Patent Document 1, a display device is known which includes a display for displaying images and a power supply circuit for outputting power necessary for displaying the images to the display. The power supply circuit converts commercial AC power into DC power, and outputs the DC power obtained by conversion to the display.
特開２０１８－１６９４６１号公報JP 2018-169461 A
　表示装置においては、表示器のみならず、電源回路においても電力が消費される。従って、表示装置の稼働に伴って電源回路が発熱し、電源回路の発熱量が大きいほど表示装置に故障が生じやすくなる。そこで、発熱が抑制される電源回路が望まれる。 In a display device, power is consumed not only in the display unit but also in the power supply circuit. Therefore, the power supply circuit generates heat as the display device operates, and the larger the amount of heat generated by the power supply circuit, the more likely the display device is to malfunction. Therefore, a power supply circuit in which heat generation is suppressed is desired.
　しかし、従来の表示装置では、映像の表示に必要な電力の低下に伴って電源回路の出力電力が低下しても、電源回路の発熱が抑えられにくい。これは、電源回路の出力電力が小さいほど、その電源回路の電力変換効率が低下するためである。つまり、電源回路の出力電力が低下しても、その電源回路における電力の損失は低下しにくく、電力の損失が発熱をもたらすので、電源回路の発熱が抑えられにくい。 However, in conventional display devices, even if the output power of the power supply circuit decreases as the power required to display images decreases, it is difficult to suppress heat generation in the power supply circuit. This is because the power conversion efficiency of the power supply circuit decreases as the output power of the power supply circuit decreases. That is, even if the output power of the power supply circuit is reduced, the power loss in the power supply circuit is unlikely to be reduced, and the power loss causes heat generation, making it difficult to suppress the heat generation of the power supply circuit.
　本開示の目的は、電源回路における発熱が従来よりも抑制される表示装置を提供することである。 An object of the present disclosure is to provide a display device in which heat generation in a power supply circuit is suppressed more than before.
　本開示に係る表示装置は、
　映像が表示される表示画面を構成する複数の表示ユニットを有し、前記表示画面に前記映像を表示するために必要な電力の大きさが変化する表示器と、
　交流電力を供給する給電部に対して並列に接続された複数台の電力変換器を有し、各々の前記電力変換器が前記交流電力を直流電力に変換する電源回路と、
　前記表示画面に前記映像を表示するために必要な電力の大きさを表す必要電力値を求め、求めた前記必要電力値に基づいて、前記必要電力値が小さいほど、前記電源回路を構成する複数台の前記電力変換器のうち稼働させる前記電力変換器である稼働電力変換器の台数が減少する条件で、前記稼働電力変換器の台数を決定し、決定した台数の前記稼働電力変換器を、前記直流電力を出力する稼働状態とし、前記電源回路を構成する複数台の前記電力変換器のうち前記稼働電力変換器以外の前記電力変換器である非稼働電力変換器を、前記直流電力の出力を断つ非稼働状態とする台数制御を行う制御装置と、
　前記稼働電力変換器によって出力された前記直流電力を、前記表示器を構成する複数の前記表示ユニットに分配する中継器と、
　を備える。 The display device according to the present disclosure is
a display device having a plurality of display units forming a display screen on which an image is displayed, wherein the amount of power required to display the image on the display screen varies;
A power supply circuit having a plurality of power converters connected in parallel to a power supply unit that supplies AC power, each of the power converters converting the AC power into DC power;
A required power value representing the magnitude of the power required to display the image on the display screen is obtained, and based on the obtained required power value, the smaller the required power value, the more the plurality of power supply circuits constituting the power supply circuit. determining the number of the operating power converters under the condition that the number of the operating power converters that are the power converters to be operated among the power converters of the set decreases, and using the determined number of the operating power converters, setting a non-operating power converter, which is the power converter other than the operating power converter among the plurality of power converters constituting the power supply circuit, to an operating state in which the DC power is output, and outputting the DC power. A control device that controls the number of units in a non-operating state that cuts off the
a repeater that distributes the DC power output by the operating power converter to a plurality of the display units that constitute the display;
Prepare.
　上記構成によれば、台数制御によって、必要電力値が小さいほど稼働電力変換器の台数が減少される。従って、必要電力が減少した場合に、稼働電力変換器の出力電力が低下しにくいため、稼働電力変換器の電力変換効率が低下しにくい。つまり、稼働電力変換器の台数が減少されても、稼働電力変換器では電力の損失が増大しにくい。一方、非稼働電力変換器の台数は必要電力値が小さいほど増大し、非稼働電力変換器では電力の消費に伴う発熱が抑制される。この結果、電源回路における発熱が従来よりも抑制される。 According to the above configuration, the smaller the required power value, the smaller the number of operating power converters due to the number control. Therefore, when the required power is reduced, the output power of the operating power converter is less likely to decrease, so the power conversion efficiency of the operating power converter is less likely to decrease. That is, even if the number of active power converters is reduced, power loss in the active power converters is less likely to increase. On the other hand, the number of non-operating power converters increases as the required power value becomes smaller, and heat generation due to power consumption is suppressed in the non-operating power converters. As a result, heat generation in the power supply circuit is suppressed more than before.
実施形態１に係る表示装置の外観を示す概念図1 is a conceptual diagram showing the appearance of a display device according to Embodiment 1. FIG. 実施形態１に係る表示装置の構成を示す概念図1 is a conceptual diagram showing the configuration of a display device according to Embodiment 1; FIG. 実施形態１に係る発熱抑制処理のフローチャートFlowchart of heat generation suppression processing according to the first embodiment 実施形態２に係る第１電力変換器の構成を示す概念図The conceptual diagram which shows the structure of the 1st power converter which concerns on Embodiment 2. 実施形態２に係る表示装置の構成を示す概念図FIG. 2 is a conceptual diagram showing the configuration of a display device according to Embodiment 2; 実施形態２に係る制御装置の構成を示す概念図FIG. 2 is a conceptual diagram showing the configuration of a control device according to Embodiment 2; 実施形態２に係る発熱抑制処理のフローチャートFlowchart of heat generation suppression processing according to the second embodiment 実施形態３に係る発熱抑制処理のフローチャートFlowchart of heat generation suppression processing according to the third embodiment 比較形態に係る表示装置の構成を示す概念図Conceptual diagram showing the configuration of a display device according to a comparative embodiment
　以下、図面を参照し、実施形態に係る表示装置について説明する。図中、同一又は対応する部分に同一の符号を付す。 A display device according to an embodiment will be described below with reference to the drawings. In the drawings, the same reference numerals are given to the same or corresponding parts.
　［実施形態１］
　図１に示すように、本実施形態に係る表示装置８００は、映像が表示される表示画面１００ａを有する表示器１００と、表示器１００を制御するための機器が収められた機器収容箱７１０とを備える。 [Embodiment 1]
As shown in FIG. 1, the display device 800 according to the present embodiment includes a display 100 having a display screen 100a on which an image is displayed, and a device storage box 710 containing devices for controlling the display 100. Prepare.
　表示器１００は、機器収容箱７１０から分離して配置されている。具体的には、表示器１００は、地面に立てられた支柱７２０の上端部分に取り付けられており、機器収容箱７１０は、支柱７２０の下端部分の脇に配置されている。 The display 100 is arranged separately from the equipment storage box 710 . Specifically, the display 100 is attached to the upper end portion of a support 720 erected on the ground, and the device housing box 710 is arranged beside the lower end portion of the support 720 .
　表示器１００と機器収容箱７１０とは、映像の表示に必要な電力を機器収容箱７１０から表示器１００に伝送する電力配線７３０と、映像の内容を表す映像データを機器収容箱７１０から表示器１００に伝送するデータ配線７４０とを含む配線群で接続されている。 The display device 100 and the device housing box 710 are connected by power wiring 730 for transmitting power necessary for displaying images from the device housing box 710 to the display device 100, and video data representing the content of the video from the device housing box 710 to the display device. 100 are connected by a wiring group including a data wiring 740 for transmission to 100 .
　表示装置８００は、屋外における道路の近傍に設置される。表示画面１００ａは、道路を走行する車両の運転手に対して、道路の混雑の状況、事故の発生の状況、通行規制の状況、天候等に関する道路情報を映像として視覚的に提供する。 The display device 800 is installed near a road outdoors. The display screen 100a visually provides the driver of the vehicle traveling on the road with road information such as road congestion, accident occurrence, traffic regulation, and weather in the form of an image.
　以下、表示器１００の構成を説明する。表示器１００は、各々映像を表示する第１表示ユニット１１０、第２表示ユニット１２０、第３表示ユニット１３０、及び第４表示ユニット１４０を有する。 The configuration of the display device 100 will be described below. The display 100 has a first display unit 110, a second display unit 120, a third display unit 130, and a fourth display unit 140, each displaying an image.
　これら第１表示ユニット１１０から第４表示ユニット１４０の４台が、マトリックス状、具体的には２行２列のマトリックス状に組み合わされることにより、全体として１つの表示画面１００ａが構成されている。 The four units of the first display unit 110 to the fourth display unit 140 are combined in a matrix, specifically in a matrix of 2 rows and 2 columns, to form a single display screen 100a as a whole.
　第１表示ユニット１１０から第４表示ユニット１４０の各々は、可視光を放射する複数の発光装置と、それら複数の発光装置が実装された回路基板とを有する。複数の発光装置は、回路基板の表面に２次元に分布して配列されている。各々の発光装置は、赤色の光を出射する赤色ＬＥＤ（Light Emitting Diode）と、緑色の光を出射する緑色ＬＥＤと、青色の光を出射する青色ＬＥＤとを有する。 Each of the first display unit 110 to the fourth display unit 140 has a plurality of light emitting devices that emit visible light, and a circuit board on which the plurality of light emitting devices are mounted. The plurality of light-emitting devices are two-dimensionally distributed and arranged on the surface of the circuit board. Each light emitting device has a red LED (Light Emitting Diode) that emits red light, a green LED that emits green light, and a blue LED that emits blue light.
　次に、機器収容箱７１０の内部の構成について説明する。 Next, the internal configuration of the device housing box 710 will be described.
　図２に示すように、表示装置８００は、商用の交流電力を出力する分電盤によって構成された給電部２００と、給電部２００から供給される交流電力を直流電力に変換する電源回路３００とを備える。表示器１００は、電源回路３００によって変換されて得られた直流電力に基づいて、表示画面１００ａに映像を表示する。 As shown in FIG. 2, the display device 800 includes a power supply unit 200 configured by a distribution board that outputs commercial AC power, and a power supply circuit 300 that converts the AC power supplied from the power supply unit 200 into DC power. Prepare. The display device 100 displays an image on the display screen 100 a based on the DC power obtained by conversion by the power supply circuit 300 .
　電源回路３００は、給電部２００に対して並列に接続された第１電力変換器３１０、第２電力変換器３２０、第３電力変換器３３０、及び第４電力変換器３４０を有する。これら第１電力変換器３１０から第４電力変換器３４０の各々が、給電部２００から供給される交流電力を直流電力に変換し、変換して得られた直流電力を出力する。 The power supply circuit 300 has a first power converter 310 , a second power converter 320 , a third power converter 330 and a fourth power converter 340 connected in parallel to the power supply section 200 . Each of the first power converter 310 to the fourth power converter 340 converts AC power supplied from the power supply unit 200 into DC power, and outputs the DC power obtained by the conversion.
　電源回路３００は、交流電力から直流電力への電力変換のために電力を消費する。従って、電源回路３００は発熱を生じ、その発熱は表示装置８００の故障の原因となる。そこで、表示装置８００における故障の発生確率を抑えるために、電源回路３００が発熱しにくい構成が望まれる。 The power supply circuit 300 consumes power for power conversion from AC power to DC power. Therefore, the power supply circuit 300 generates heat, which causes the display device 800 to malfunction. Therefore, in order to reduce the probability of failure occurring in the display device 800, a configuration in which the power supply circuit 300 hardly generates heat is desired.
　以下、本実施形態で解決しようとする課題を具体的に示すために、比較形態について説明する。 A comparative form will be described below in order to specifically show the problems to be solved by this embodiment.
　図９に示すように、比較形態に係る表示装置９００では、第１表示ユニット１１０から第４表示ユニット１４０の４台と、第１電力変換器３１０から第４電力変換器３４０の４台とが、１対１に対応付けられている。 As shown in FIG. 9, in the display device 900 according to the comparative embodiment, four display units 110 to 140 and four power converters 310 to 440 are provided. , are associated one-to-one.
　つまり、第１表示ユニット１１０は、専ら第１電力変換器３１０から給電を受ける。第２表示ユニット１２０は、専ら第２電力変換器３２０から給電を受ける。第３表示ユニット１３０は、専ら第３電力変換器３３０から給電を受ける。第４表示ユニット１４０は、専ら第４電力変換器３４０から給電を受ける。 That is, the first display unit 110 receives power exclusively from the first power converter 310 . The second display unit 120 is exclusively powered by the second power converter 320 . The third display unit 130 is exclusively powered by the third power converter 330 . The fourth display unit 140 is exclusively powered by the fourth power converter 340 .
　このため、表示画面１００ａに映像を表示させるために、比較形態に係る制御装置９１０は、第１電力変換器３１０から第４電力変換器３４０のすべてを並行して常時に稼働させる。第１電力変換器３１０から第４電力変換器３４０の各々は、稼働中、電力変換のために電力を消費するため、電源回路３００に発熱が生じる。 For this reason, in order to display an image on the display screen 100a, the control device 910 according to the comparative embodiment always operates all of the first power converter 310 to the fourth power converter 340 in parallel. Since each of the first power converter 310 to the fourth power converter 340 consumes power for power conversion during operation, heat is generated in the power supply circuit 300 .
　一方、表示画面１００ａに映像を表示するために必要な電力の大きさは、表示画面１００ａの面内における輝度の合計値に応じて時間的に変化する。そこで、表示画面１００ａに映像を表示するために必要な電力が低下した場合には、電源回路３００の総出力電力が低下するため、電源回路３００の発熱が抑えられることが期待される。 On the other hand, the amount of power required to display an image on the display screen 100a temporally changes according to the total value of luminance within the plane of the display screen 100a. Therefore, when the power required to display an image on the display screen 100a is reduced, the total output power of the power supply circuit 300 is reduced.
　しかし、表示装置９００では、映像の表示に必要な電力の低下に伴って電源回路３００の総出力電力が低下しても、電源回路３００の発熱が抑えられにくい。これは第１電力変換器３１０から第４電力変換器３４０の各々が、出力電力が小さいほど電力変換効率が低下する特性をもつからである。 However, in the display device 900, even if the total output power of the power supply circuit 300 is reduced as the power necessary for displaying images is reduced, it is difficult to suppress the heat generation of the power supply circuit 300. This is because each of the first power converter 310 to the fourth power converter 340 has a characteristic that the lower the output power, the lower the power conversion efficiency.
　ここで、電力変換器の電力変換効率とは、電力変換器が出力した出力電力を、その電力変換器に入力された入力電力で割った値を指す。電力変換器の電力変更効率をη［％］としたとき、１００－η［％］は、その電力変換器で消費される電力、即ち、その電力変換における電力の損失の割合を表す。電力の損失が大きいほど発熱が大きい。 Here, the power conversion efficiency of a power converter refers to the value obtained by dividing the output power output by the power converter by the input power input to the power converter. When the power change efficiency of the power converter is η [%], 100−η [%] represents the power consumed by the power converter, that is, the rate of power loss in the power conversion. The greater the power loss, the greater the heat generation.
　つまり、第１電力変換器３１０から第４電力変換器３４０の各々の出力電力が低下しても、これらの各々における電力の損失は低下しにくい。また、既述のように、比較形態では、第１電力変換器３１０から第４電力変換器３４０のすべてを常時に稼働させるので、これら４台のすべてにおいて電力の損失に伴う発熱が生じる。 That is, even if the output power of each of the first power converter 310 to the fourth power converter 340 is reduced, the power loss in each of these is unlikely to be reduced. Further, as described above, in the comparative embodiment, all of the first power converter 310 to the fourth power converter 340 are always operated, so heat is generated due to power loss in all of these four power converters.
　このため、電源回路３００全体としての発熱が抑えられにくい。電源回路３００の発熱は、電源回路３００自身の故障の原因となり、かつ図１に示した機器収容箱７１０に電源回路３００と共に収容される機器の故障の原因となる。 Therefore, it is difficult to suppress heat generation in the power supply circuit 300 as a whole. The heat generated by the power supply circuit 300 causes failure of the power supply circuit 300 itself and failure of the equipment housed together with the power supply circuit 300 in the equipment housing box 710 shown in FIG.
　以上説明した課題を解決するために、本実施形態では、電源回路３００が発熱しにくい構成を採用した。以下、図２に戻り、本実施形態の構成を具体的に説明する。 In order to solve the above-described problems, this embodiment adopts a configuration in which the power supply circuit 300 is less likely to generate heat. Hereinafter, referring back to FIG. 2, the configuration of this embodiment will be specifically described.
　図２に示すように、本実施形態に係る表示装置８００は、電源回路３００と給電部２００との間に接続された開閉器群４００と、電源回路３００と表示器１００との間に接続された中継器５００と、表示器１００、電源回路３００、開閉器群４００、及び中継器５００を制御する制御装置６００とをさらに備える。 As shown in FIG. 2, a display device 800 according to the present embodiment includes a switch group 400 connected between a power supply circuit 300 and a power supply section 200, and a switch group 400 connected between the power supply circuit 300 and a display device 100. and a controller 600 that controls the display 100 , the power supply circuit 300 , the group of switches 400 , and the repeater 500 .
　なお、給電部２００、電源回路３００、開閉器群４００、中継器５００、及び制御装置６００が、図１に示した機器収容箱７１０に収容される。 The power supply unit 200, the power supply circuit 300, the switch group 400, the repeater 500, and the control device 600 are housed in the equipment housing box 710 shown in FIG.
　開閉器群４００は、第１電力変換器３１０と給電部２００との間に介在する第１開閉器４１０と、第２電力変換器３２０と給電部２００との間に介在する第２開閉器４２０と、第３電力変換器３３０と給電部２００との間に介在する第３開閉器４３０と、第４電力変換器３４０と給電部２００との間に介在する第４開閉器４４０とを有する。 The switch group 400 includes a first switch 410 interposed between the first power converter 310 and the power supply section 200 and a second switch 420 interposed between the second power converter 320 and the power supply section 200. , a third switch 430 interposed between the third power converter 330 and the power supply section 200 , and a fourth switch 440 interposed between the fourth power converter 340 and the power supply section 200 .
　第１開閉器４１０は、第１電力変換器３１０を給電部２００に導通させる導通状態と、第１電力変換器３１０を給電部２００から遮断する遮断状態とに切り換えが可能である。第２開閉器４２０は、第２電力変換器３２０を給電部２００に導通させる導通状態と、第２電力変換器３２０を給電部２００から遮断する遮断状態とに切り換えが可能である。第３開閉器４３０は、第３電力変換器３３０を給電部２００に導通させる導通状態と、第３電力変換器３３０を給電部２００から遮断する遮断状態とに切り換えが可能である。第４開閉器４４０は、第４電力変換器３４０を給電部２００に導通させる導通状態と、第４電力変換器３４０を給電部２００から遮断する遮断状態とに切り換えが可能である The first switch 410 can be switched between a conductive state in which the first power converter 310 is connected to the power supply unit 200 and a cutoff state in which the first power converter 310 is cut off from the power supply unit 200 . Second switch 420 can be switched between a conductive state in which second power converter 320 is connected to power supply unit 200 and a cutoff state in which second power converter 320 is cut off from power supply unit 200 . Third switch 430 can be switched between a conductive state in which third power converter 330 is connected to power supply unit 200 and a cutoff state in which third power converter 330 is cut off from power supply unit 200 . The fourth switch 440 can be switched between a conductive state in which the fourth power converter 340 is connected to the power supply unit 200 and a cutoff state in which the fourth power converter 340 is cut off from the power supply unit 200 .
　既述のとおり、表示装置８００の稼働中、表示画面１００ａに映像を表示するために必要な電力の大きさは変化する。制御装置６００は、表示画面１００ａに映像を表示するために必要な電力の大きさを表す必要電力値ＷＸを求め、求めた必要電力値ＷＸに基づいて、必要電力値ＷＸが小さいほど、第１電力変換器３１０から第４電力変換器３４０のうち稼働させるもの（以下、稼働電力変換器という。）の台数を減少させる台数制御を行う。 As described above, while the display device 800 is in operation, the amount of power required to display an image on the display screen 100a changes. The control device 600 obtains a required power value WX representing the amount of power required to display an image on the display screen 100a. The number of power converters 310 to the fourth power converter 340 is controlled to reduce the number of those to be operated (hereinafter referred to as "operating power converters").
　具体的には、制御装置６００は、台数制御において、稼働電力変換器を、直流電力を出力する稼働状態に制御する一方、第１電力変換器３１０から第４電力変換器３４０のうち稼働電力変換器以外のもの（以下、非稼働電力変換器という。）を、直流電力の出力を断つ非稼働状態に制御する。 Specifically, in the number control, the control device 600 controls the operating power converters to an operating state in which DC power is output, while controlling the operating power converters among the first power converter 310 to the fourth power converter 340. Controls other devices (hereinafter referred to as non-operating power converters) to a non-operating state that cuts off the output of DC power.
　台数制御は、制御装置６００が、第１開閉器４１０から第４開閉器４４０のうち、稼働電力変換器に対して設けられたものを導通状態に制御する一方、非稼働電力変換器に対して設けられたものを遮断状態に制御することにより実現される。 In the number control, the control device 600 controls the first switch 410 to the fourth switch 440, which are provided for the operating power converters, to be in a conductive state, while the non-operating power converters are It is realized by controlling the provided one to the cut-off state.
　中継器５００は、電源回路３００の稼働電力変換器によって出力された直流電力を、第１表示ユニット１１０から第４表示ユニット１４０に分配する。なお、稼働電力変換器の台数が２台以上である場合は、中継器５００はすべての稼働電力変換器が出力する直流電力を合成したうえで、合成された直流電力を第１表示ユニット１１０から第４表示ユニット１４０に分配する。ここで“合成”とは加算を意味する。 The repeater 500 distributes the DC power output by the operating power converter of the power supply circuit 300 from the first display unit 110 to the fourth display unit 140 . When the number of operating power converters is two or more, the repeater 500 synthesizes the DC power output from all the operating power converters, and outputs the synthesized DC power from the first display unit 110. distributed to the fourth display unit 140; Here "synthesis" means addition.
　但し、稼働電力変換器の台数が１台の場合もあり得る。その場合、中継器５００は、その稼働電力変換器が出力する直流電力を第１表示ユニット１１０から第４表示ユニット１４０に分配する。 However, it is possible that the number of operating power converters is one. In that case, repeater 500 distributes the DC power output by its active power converter from first display unit 110 to fourth display unit 140 .
　また、中継器５００は、電源回路３００の稼働電力変換器から出力された直流電圧を、安定化のために降下させる電圧降下部５１０を有する。電圧降下部５１０で降下される電圧の大きさが制御装置６００の制御によって可変に調整されてもよい。上述した必要電力値とは、電圧降下部５１０における電圧降下を見越した値とする。稼働電力変換器から出力された直流電圧を電圧降下部５１０で降下させることにより、電力配線７３０の直径を小さく抑えることができる。 The repeater 500 also has a voltage drop section 510 that drops the DC voltage output from the operating power converter of the power supply circuit 300 for stabilization. The magnitude of the voltage dropped by voltage drop unit 510 may be variably adjusted under the control of control device 600 . The required power value described above is a value that allows for a voltage drop in the voltage drop section 510 . By dropping the DC voltage output from the operating power converter by the voltage drop section 510, the diameter of the power wiring 730 can be kept small.
　また、制御装置６００は、表示器１００の制御も行う。以下、この点について説明する。表示器１００に表示する映像の内容を表す映像データは、外部の映像配信センタＶＤから制御装置６００へ送信される。 The control device 600 also controls the display device 100 . This point will be described below. Video data representing the content of the video to be displayed on the display device 100 is transmitted from an external video distribution center VD to the control device 600 .
　一方、制御装置６００は、映像配信センタＤＶから時々刻々送信される映像データを一時的に蓄積するバッファメモリ６１０を有する。バッファメモリ６１０は、少なくとも２フレーム分の映像データを書き込み可能な記憶容量を有する。なお、フレームとは、映像を表す動画を構成する静止画像１コマのことをいう。 On the other hand, the control device 600 has a buffer memory 610 that temporarily accumulates video data transmitted from the video distribution center DV every moment. The buffer memory 610 has a storage capacity capable of writing video data for at least two frames. Note that a frame is one frame of a still image forming a moving image representing video.
　制御装置６００は、バッファメモリ６１０に既に書き込んだ１フレーム分の映像データをバッファメモリ６１０から読み出し、読み出した映像データを、データ配線７４０を通じて表示器１００に伝送する。また、制御装置６００は、バッファメモリ６１０からの映像データの読み出しと並行して、映像配信センタＤＶから取得した次のフレームの映像データの、バッファメモリ６１０への書き込みを行う。 The control device 600 reads from the buffer memory 610 the video data for one frame already written to the buffer memory 610 and transmits the read video data to the display device 100 through the data wiring 740 . In parallel with reading the video data from the buffer memory 610 , the control device 600 writes the video data of the next frame obtained from the video distribution center DV to the buffer memory 610 .
　このようにして、制御装置６００は、表示器１００に対して映像データをフレーム単位で次々に伝送する。表示器１００では、制御装置６００から伝送された映像データに基づいて、第１表示ユニット１１０から第４表示ユニット１４０の各々を構成する発光装置のＰＷＭ（Pulse Width Modulation）制御が行われる。これにより、表示画面１００ａへの映像の表示が実現される。 In this way, the control device 600 sequentially transmits video data to the display device 100 frame by frame. In the display device 100, PWM (Pulse Width Modulation) control of the light emitting devices constituting each of the first display unit 110 to the fourth display unit 140 is performed based on the video data transmitted from the control device 600. As a result, the image is displayed on the display screen 100a.
　制御装置６００は、上述した台数制御を、表示器１００への映像データの伝送と並行して行う。具体的には、制御装置６００は、映像配信センタＤＶから１フレーム分の映像データを取得する度に、その１フレーム分の映像データを用いて、そのフレームにおける表示画面１００ａの面内にわたる輝度の合計値を求める。ここで“輝度の合計値”とは、表示画面１００ａを構成する各々の画素の輝度を、すべての画素について足し算した値を意味する。なお、１つの発光装置が１つの画素を構成する。 The control device 600 performs the above-described number control in parallel with transmission of video data to the display device 100 . Specifically, each time one frame of video data is acquired from the video distribution center DV, the control device 600 uses the one frame of video data to determine the brightness of the display screen 100a in that frame. Find the total value. Here, the "total value of luminance" means a value obtained by adding the luminance of each pixel constituting the display screen 100a for all pixels. Note that one light-emitting device constitutes one pixel.
　次に、制御装置６００は、求めた輝度の合計値に基づいて、表示画面１００ａに映像を表示するために必要な電力の大きさを表す必要電力値ＷＸを求める。そして、制御装置６００は、求めた必要電力値ＷＸを用いて、上述した台数制御を行う。 Next, the control device 600 obtains a required power value WX representing the magnitude of power required to display an image on the display screen 100a based on the calculated total luminance value. Then, the control device 600 performs the above-described number control using the obtained required power value WX.
　以下、台数制御によって電源回路３００の発熱を抑える発熱抑制処理について述べる。 The heat generation suppression process for suppressing the heat generation of the power supply circuit 300 by controlling the number of units will be described below.
　図３に示すように、まず、制御装置６００は、上述のように映像配信センタＤＶから取得した映像データを用いて、必要電力値ＷＸを求める（ステップＳ１１）。 As shown in FIG. 3, the control device 600 first obtains the required power value WX using the video data acquired from the video distribution center DV as described above (step S11).
　そして、制御装置６００は、必要電力値ＷＸが、第１電力変換器３１０で出力可能な電力の上限値として予め定められた第１閾値Ｗ１以下である場合には（ステップＳ１２；ＹＥＳ）、第１電力変換器３１０を稼働電力変換器として稼働させる（ステップＳ１３）。 Then, when the required power value WX is equal to or less than a first threshold value W1 predetermined as the upper limit value of the power that can be output from the first power converter 310 (step S12; YES), the control device 600 1 The power converter 310 is operated as an active power converter (step S13).
　また、制御装置６００は、第２電力変換器３２０から第４電力変換器３４０を非稼働電力変換器として停止させる。具体的には、制御装置６００は、第１開閉器４１０を導通状態に制御し、第２開閉器４２０から第４開閉器４４０を遮断状態に制御する。 In addition, the control device 600 stops the second power converter 320 to the fourth power converter 340 as non-operating power converters. Specifically, the control device 600 controls the first switch 410 to be conductive, and controls the second switch 420 to the fourth switch 440 to be disconnected.
　この場合、中継器５００は、第１電力変換器３１０の出力電圧を、電圧降下部５１０で適宜降下させたうえで、第１表示ユニット１１０から第４表示ユニット１４０に均等に分配する。 In this case, the repeater 500 appropriately drops the output voltage of the first power converter 310 in the voltage drop section 510 and distributes it evenly from the first display unit 110 to the fourth display unit 140 .
　一方、制御装置６００は、必要電力値ＷＸが、第１閾値Ｗ１よりも大きく（ステップＳ１２；ＮＯ）、かつ第１電力変換器３１０及び第２電力変換器３２０の２台の合計で出力可能な電力の上限値として予め定められた第２閾値Ｗ２以下である場合には（ステップＳ１４；ＹＥＳ）、第１電力変換器３１０及び第２電力変換器３２０を稼働電力変換器として稼働させる（ステップＳ１５）。 On the other hand, the controller 600 determines that the required power value WX is greater than the first threshold value W1 (step S12; NO), and that the total of the first power converter 310 and the second power converter 320 can output If it is equal to or less than the second threshold value W2 predetermined as the upper limit of power (step S14; YES), the first power converter 310 and the second power converter 320 are operated as operating power converters (step S15 ).
　また、制御装置６００は、第３電力変換器３３０及び第４電力変換器３４０を非稼働電力変換器として停止させる。具体的には、制御装置６００は、第１開閉器４１０及び第２開閉器４２０を導通状態に制御し、第３開閉器４３０及び第４開閉器４４０を遮断状態に制御する。 In addition, the control device 600 stops the third power converter 330 and the fourth power converter 340 as non-operating power converters. Specifically, the control device 600 controls the first switch 410 and the second switch 420 to be conductive, and controls the third switch 430 and the fourth switch 440 to be disconnected.
　この場合、中継器５００は、第１電力変換器３１０及び第２電力変換器３２０の出力電圧を合成し、かつ電圧降下部５１０で適宜降下させたうえで、第１表示ユニット１１０から第４表示ユニット１４０に均等に分配する。 In this case, the repeater 500 synthesizes the output voltages of the first power converter 310 and the second power converter 320 , appropriately lowers the voltage in the voltage drop section 510 , and outputs the voltage from the first display unit 110 to the fourth display. Distribute evenly among units 140 .
　一方、制御装置６００は、必要電力値ＷＸが、第２閾値Ｗ２よりも大きく（ステップＳ１４；ＮＯ）、かつ第１電力変換器３１０から第３電力変換器３３０の３台の合計で出力可能な電力の上限値として予め定められた第３閾値Ｗ３以下である場合には（ステップＳ１６；ＹＥＳ）、第１電力変換器３１０から第３電力変換器３３０を稼働電力変換器として稼働させる（ステップＳ１７）。 On the other hand, control device 600 determines that required electric power value WX is greater than second threshold value W2 (step S14; NO), and the total of three power converters 310 to 330 can output When it is equal to or less than the third threshold value W3 predetermined as the upper limit value of power (step S16; YES), the first power converter 310 to the third power converter 330 are operated as operating power converters (step S17 ).
　また、制御装置６００は、第４電力変換器３４０を非稼働電力変換器として停止させる。具体的には、制御装置６００は、第１開閉器４１０から第３開閉器４３０を導通状態に制御し、第４開閉器４４０を遮断状態に制御する。 Also, the control device 600 stops the fourth power converter 340 as a non-operating power converter. Specifically, the control device 600 controls the first switch 410 to the third switch 430 to be conductive, and controls the fourth switch 440 to be disconnected.
　この場合、中継器５００は、第１電力変換器３１０から第３電力変換器３３０の出力電圧を合成し、かつ電圧降下部５１０で適宜降下させたうえで、第１表示ユニット１１０から第４表示ユニット１４０に均等に分配する。 In this case, the repeater 500 synthesizes the output voltages of the first power converter 310 to the third power converter 330 , appropriately lowers the voltage in the voltage drop section 510 , and then outputs the voltage from the first display unit 110 to the fourth display. Distribute evenly among units 140 .
　一方、制御装置６００は、必要電力値ＷＸが、第３閾値Ｗ３よりも大きい場合には（ステップＳ１６；ＮＯ）、第１電力変換器３１０から第４電力変換器３４０のすべてを稼働電力変換器として稼働させる（ステップＳ１８）。具体的には、制御装置６００は、第１開閉器４１０から第４開閉器４４０を導通状態に制御する。 On the other hand, when the required power value WX is greater than the third threshold value W3 (step S16; NO), the control device 600 sets all of the first power converter 310 to the fourth power converter 340 to the operating power converter. (step S18). Specifically, the control device 600 controls the first switch 410 to the fourth switch 440 to be conductive.
　この場合、中継器５００は、第１電力変換器３１０から第４電力変換器３４０の出力電圧を合成し、かつ電圧降下部５１０で適宜降下させたうえで、第１表示ユニット１１０から第４表示ユニット１４０に均等に分配する。 In this case, the repeater 500 synthesizes the output voltages of the first power converter 310 to the fourth power converter 340 , appropriately lowers the voltage in the voltage drop section 510 , and then outputs the voltage from the first display unit 110 to the fourth display. Distribute evenly among units 140 .
　以上説明したステップＳ１１からＳ１８までの処理が必要電力値ＷＸが小さいほど稼働電力変換器の台数を減少させる台数制御を表す。 The processing from steps S11 to S18 described above represents number control in which the number of operating power converters is decreased as the required power value WX is smaller.
　次に、制御装置６００は、表示器１００での映像の表示を終了する場合は（ステップＳ１９；ＹＥＳ）、本発熱抑制処理を終了する。一方、制御装置６００は、表示器１００での映像の表示を継続する場合は（ステップＳ１９；ＮＯ）、再びステップＳ１１に戻り、台数制御を繰り返す。 Next, when the control device 600 ends the display of the image on the display device 100 (step S19; YES), the heat generation suppression process ends. On the other hand, when the control device 600 continues to display the image on the display device 100 (step S19; NO), the control device 600 returns to step S11 again and repeats the number control.
　台数制御の繰り返し周波数、即ち、ステップＳ１１からＳ１８の繰り返し周波数は、表示画面１００ａにおける映像のフレームレートに等しい。ここでフレームレートとは、１秒間に表示させる静止画像の数、即ち１秒あたりのコマの数をいう。本実施形態ではフレームレートは０．５Ｈｚ以上、５Ｈｚ以下、具体的には、１Ｈｚ以上、２Ｈｚ以下である。 The repetition frequency of the number control, that is, the repetition frequency of steps S11 to S18 is equal to the frame rate of the video on the display screen 100a. Here, the frame rate means the number of still images displayed per second, that is, the number of frames per second. In this embodiment, the frame rate is 0.5 Hz or more and 5 Hz or less, specifically 1 Hz or more and 2 Hz or less.
　以下、図２に示す電源回路３００で消費される電力、即ち電源回路３００における損失電力の具体値を例示する。 Specific values of the power consumed by the power supply circuit 300 shown in FIG.
　前提として、第１電力変換器３１０から第４電力変換器３４０の各々は、出力電力が１００Ｗの場合に９５％の電力変換効率を示し、出力電力が５０Ｗの場合には９０％の電力変換効率を示すものとする。また、上述した第１閾値Ｗ１が１５０［Ｗ］であり、第２閾値Ｗ２が２５０［Ｗ］であり、必要電力値ＷＸが２００［Ｗ］であったとする。 As an assumption, each of the first power converter 310 to the fourth power converter 340 exhibits a power conversion efficiency of 95% when the output power is 100W, and a power conversion efficiency of 90% when the output power is 50W. shall indicate Also, assume that the first threshold W1 is 150 [W], the second threshold W2 is 250 [W], and the required power value WX is 200 [W].
　この場合、図３に示す台数制御によれば、ステップＳ１５で、第１電力変換器３１０と第２電力変換器３２０とが稼働電力変換器として稼働される。これら第１電力変換器３１０と第２電力変換器３２０との２台で、必要電力値ＷＸである２００［Ｗ］を均等に分担するので、１台あたり１００［Ｗ］の出力電力が必要である。 In this case, according to the number control shown in FIG. 3, in step S15, the first power converter 310 and the second power converter 320 are operated as operating power converters. Since the first power converter 310 and the second power converter 320 equally share the required power value WX of 200 [W], each power converter requires an output power of 100 [W]. be.
　そして、上述のとおり、出力電力が１００Ｗの場合の電力変換効率は９５％なので、第１電力変換器３１０と第２電力変換器３２０との各々における損失電力は、（１００／０．９５）×０．０５≒５．３［Ｗ］となる。つまり、１００Ｗの出力電力を得るには約１０５．３［Ｗ］の入力電力が必要であり、そのうち５．３［Ｗ］が消費される。 As described above, the power conversion efficiency is 95% when the output power is 100 W, so the power loss in each of first power converter 310 and second power converter 320 is (100/0.95)× 0.05≈5.3 [W]. That is, to obtain 100 W of output power, approximately 105.3 [W] of input power is required, of which 5.3 [W] is consumed.
　一方、第３電力変換器３３０及び第４電力変換器３４０は、非稼働電力変換器とされるので、これらにおける損失電力は、実質的にゼロである。従って、電源回路３００の全体としての損失電力は、５．３×２＝１０．６［Ｗ］である。この場合、電源回路３００には、１０．６［Ｗ］分の発熱が生じる。 On the other hand, since the third power converter 330 and the fourth power converter 340 are non-operating power converters, the power loss in these is substantially zero. Therefore, the power loss of the power supply circuit 300 as a whole is 5.3×2=10.6 [W]. In this case, the power supply circuit 300 generates heat of 10.6 [W].
　一方、既述の比較形態によれば、第１電力変換器３１０から第４電力変換器３４０の４台で必要電力値ＷＸである２００［Ｗ］を均等に分担するので、１台あたりの出力電力は５０［Ｗ］に抑えられる。そして、上述のとおり、出力電力が５０Ｗの場合の電力変換効率は９０％なので、第１電力変換器３１０から第４電力変換器３４０の各々における損失電力は、（５０／０．９）×０．１≒５．６［Ｗ］となる。 On the other hand, according to the above-described comparative form, the four power converters 310 to 340 equally share the required power value WX of 200 [W], so the output per unit Electric power is suppressed to 50 [W]. Then, as described above, since the power conversion efficiency is 90% when the output power is 50 W, the power loss in each of the first power converter 310 to the fourth power converter 340 is (50/0.9)×0 .1≈5.6 [W].
　従って、比較形態では、電源回路３００の全体としての損失電力が、５．６×４＝２２．４［Ｗ］にまで達する。以上のとおり、本実施形態の台数制御によれば、電源回路３００の全体としての損失電力が、比較形態の場合の半分未満に抑えられる。従って、比較形態の場合よりも電源回路３００の発熱が抑制される。 Therefore, in the comparative form, the power loss of the power supply circuit 300 as a whole reaches 5.6×4=22.4 [W]. As described above, according to the number control of the present embodiment, the power loss of the power supply circuit 300 as a whole can be suppressed to less than half of that in the comparative embodiment. Therefore, heat generation of the power supply circuit 300 is suppressed more than in the case of the comparison mode.
　以上説明したように、本実施形態によれば、制御装置６００が行う台数制御によって、必要電力値ＷＸが小さいほど稼働電力変換器の台数が減少される。従って、必要電力値ＷＸが減少した場合に、稼働電力変換器の出力電力が低下しにくい。 As described above, according to the present embodiment, the smaller the required power value WX is, the smaller the number of operating power converters is reduced by the number control performed by the control device 600 . Therefore, when the required power value WX decreases, the output power of the operating power converter is less likely to decrease.
　第１電力変換器３１０から第４電力変換器３４０の各々は、出力電力が小さいほど電力変換効率が低下する特性をもつので、稼働電力変換器の出力電力が低下しにくいということは、稼働電力変換器における電力変換効率が低下しにくいということを意味する。つまり、必要電力値ＷＸの減少に伴って稼働電力変換器の台数が減少されても、稼働電力変換器では電力の損失が増大しにくい。 Each of the first power converter 310 to the fourth power converter 340 has a characteristic that the lower the output power, the lower the power conversion efficiency. This means that the power conversion efficiency in the converter is less likely to decrease. That is, even if the number of operating power converters is reduced as the required power value WX decreases, power loss in the operating power converters is less likely to increase.
　一方、非稼働電力変換器の台数は、必要電力値ＷＸが小さいほど増大し、非稼働電力変換器では電力の消費に伴う発熱が抑制される。この結果、電源回路３００における発熱が比較形態の場合よりも抑制される。 On the other hand, the number of non-operating power converters increases as the required power value WX decreases, and the heat generated by the non-operating power converters due to power consumption is suppressed. As a result, heat generation in the power supply circuit 300 is suppressed more than in the case of the comparative embodiment.
　また、本実施形態に係る台数制御によれば、第２電力変換器３２０から第４電力変換器３４０については、常時に稼働される訳ではなく選択的に稼働される。従って、第１電力変換器３１０から第４電力変換器３４０の４台を常時に稼働させる比較形態に比べると、第２電力変換器３２０から第４電力変換器３４０の各々が稼働する期間が低減される。この結果、電源回路３００の長寿命化、ひいては表示装置８００の長寿命化が図られる。 Also, according to the number control according to the present embodiment, the second power converter 320 to the fourth power converter 340 are not always operated, but are selectively operated. Therefore, compared to the comparative form in which the four power converters 310 to 340 are always operated, the period during which each of the second power converter 320 to the fourth power converter 340 is operated is reduced. be done. As a result, the life of the power supply circuit 300 and thus the life of the display device 800 can be extended.
　なお、本実施形態において、第１電力変換器３１０から第４電力変換器３４０の電力変換特性は互いに等しくてもよい。つまり、第１電力変換器３１０から第４電力変換器３４０の各々における、出力電力に対する電力変換効率の依存性は実質的に等しくてもよい。電力変換特性が実質的に等しい第１電力変換器３１０から第４電力変換器３４０を用いることができるので、電源回路３００の製造の容易化及び生産管理の容易化が図られる。 Note that in the present embodiment, the power conversion characteristics of the first power converter 310 to the fourth power converter 340 may be the same. That is, the dependence of the power conversion efficiency on the output power may be substantially the same in each of the first power converter 310 to the fourth power converter 340 . Since the first to fourth power converters 310 to 340 having substantially the same power conversion characteristics can be used, the power supply circuit 300 can be easily manufactured and easily managed.
　［実施形態２］
　上記実施形態１では、第１電力変換器３１０から第４電力変換器３４０の各々の稼働状態と非稼働状態との切り換えを、開閉器群４００を用いて実現した。開閉器群４００を用いずに、第１電力変換器３１０から第４電力変換器３４０の各々を制御することにより、稼働状態と非稼働状態との切り換えを行ってもよい。以下、その具体例を述べる。 [Embodiment 2]
In the first embodiment described above, switching between the operating state and the non-operating state of each of the first power converter 310 to the fourth power converter 340 is realized using the switch group 400 . Switching between the operating state and the non-operating state may be performed by controlling each of the first power converter 310 to the fourth power converter 340 without using the switch group 400 . A specific example will be described below.
　図４に、第１電力変換器３１０の構成を例示する。第１電力変換器３１０は、図２に示した給電部２００から交流電力が入力される１次回路３５１と、図２に示した中継器５００に直流電力を出力する２次回路３５２と、１次回路３５１と２次回路３５２との間に介在する変圧器３５３と、変圧器３５３に接続されたスイッチング素子３５４とを有するスイッチング電源（switched-mode power supply）である。なお、１次回路３５１は、電圧を平滑化するための平滑化用キャパシタ３５１ａを含む。 The configuration of the first power converter 310 is illustrated in FIG. The first power converter 310 includes a primary circuit 351 to which AC power is input from the power supply unit 200 shown in FIG. 2, a secondary circuit 352 to output DC power to the repeater 500 shown in FIG. It is a switched-mode power supply having a transformer 353 interposed between a secondary circuit 351 and a secondary circuit 352 and a switching element 354 connected to the transformer 353 . The primary circuit 351 includes a smoothing capacitor 351a for smoothing the voltage.
　１次回路３５１が交流電力を整流し、かつスイッチング素子３５４がＯＮとＯＦＦに交互に繰り返し切り換わるスイッチング動作を行っているとき、変圧器３５３を通じて１次回路３５１から２次回路３５２へと方形波状の電圧の印可が許容される。２次回路３５２は、印加された方形波状の電圧を直流電圧へと平滑化する。この結果、第１電力変換器３１０における交流電力から直流電力への変換が実現される。つまり、第１電力変換器３１０が稼働状態となる。 When the primary circuit 351 rectifies AC power and the switching element 354 is switching repeatedly alternately ON and OFF, a square wave current is passed from the primary circuit 351 to the secondary circuit 352 through the transformer 353 . of voltage is allowed. Secondary circuit 352 smoothes the applied square-wave voltage to a DC voltage. As a result, conversion from AC power to DC power in first power converter 310 is realized. That is, the first power converter 310 is in an operating state.
　一方、スイッチング素子３５４がスイッチング動作を停止すると、具体的には、スイッチング素子３５４が遮断状態又は導通状態に保たれると、１次回路３５１から２次回路３５２への電圧の印可が阻止される。従って、第１電力変換器３１０が非稼働状態となる。 On the other hand, when the switching element 354 stops switching operation, specifically, when the switching element 354 is kept in the cut-off state or the conducting state, application of voltage from the primary circuit 351 to the secondary circuit 352 is blocked. . Therefore, the first power converter 310 is put into a non-operating state.
　また、図２に示した第２電力変換器３２０から第４電力変換器３４０も、第１電力変換器３１０と同様に、図４に示す構成と同じ構成を備えるスイッチング電源である。 Further, like the first power converter 310, the second power converter 320 to the fourth power converter 340 shown in FIG. 2 are switching power supplies having the same configuration as that shown in FIG.
　図５は、本実施形態に係る表示装置８００の構成を示す。図５に示すように、本実施形態に係る表示装置８００は、図２に示した開閉器群４００を備えない。本実施形態では制御装置６００は、台数制御において、非稼働電力変換器のスイッチング素子３５４にスイッチング動作を停止させることにより、非稼働電力変換器を非稼働状態とする。一方、制御装置６００は、稼働電力変換器のスイッチング素子３５４にはスイッチング動作を行わせることにより、稼働電力変換器を稼働状態とする。 FIG. 5 shows the configuration of a display device 800 according to this embodiment. As shown in FIG. 5, the display device 800 according to this embodiment does not include the switch group 400 shown in FIG. In the present embodiment, the control device 600 puts the non-operating power converters in the non-operating state by causing the switching elements 354 of the non-operating power converters to stop switching operations in the number control. On the other hand, the control device 600 puts the operating power converter into the operating state by causing the switching element 354 of the operating power converter to perform a switching operation.
　本実施形態によれば、図２に示した開閉器群４００が不要であるため、表示装置８００を構成する部品点数を削減できる。 According to this embodiment, the switch group 400 shown in FIG. 2 is unnecessary, so the number of parts constituting the display device 800 can be reduced.
　また、図２に示した開閉器群４００を用いる場合は、非稼働電力変換器を稼働電力変換器に切り換えた際、図４に示す１次回路３５１の平滑化用キャパシタ３５１ａが充電された後でなければ、２次回路３５２からの直流電力の出力が開始しない。 Further, when the switch group 400 shown in FIG. 2 is used, when the non-operating power converter is switched to the operating power converter, after the smoothing capacitor 351a of the primary circuit 351 shown in FIG. Otherwise, output of DC power from the secondary circuit 352 will not start.
　これに対し、本実施形態では、図２に示すスイッチング素子３５４にスイッチング動作を停止させ、スイッチング素子３５４をＯＦＦに保つ期間は、１次回路３５１の平滑化用キャパシタが充電された状態に維持される。このため、非稼働電力変換器を稼働電力変換器に切り換えた際に、平滑化用キャパシタ３５１ａの充電を待つ必要がないので、直ちに２次回路３５２からの直流電力の出力が開始する。従って、本実施形態によれば、映像のフレームレートが高い場合でも、非稼働状態から稼働状態に切り換えられた稼働電力変換器からの直流電力の供給が途切れにくい。 On the other hand, in the present embodiment, the switching operation of the switching element 354 shown in FIG. be. Therefore, when the non-operating power converter is switched to the operating power converter, there is no need to wait for the smoothing capacitor 351a to be charged, so the output of the DC power from the secondary circuit 352 starts immediately. Therefore, according to the present embodiment, even when the video frame rate is high, the supply of DC power from the operating power converter that has been switched from the non-operating state to the operating state is less likely to be interrupted.
　［実施形態３］
　図３に示した発熱抑制処理では、第４電力変換器３４０の稼働の頻度が、第１電力変換器３１０の稼働の頻度よりも小さくなる。そこで、第１電力変換器３１０から第４電力変換器３４０の稼働の頻度にばらつきが生じにくい構成が望まれる。以下、その構成の具体例を述べる。 [Embodiment 3]
In the heat generation suppression process illustrated in FIG. 3 , the frequency of operation of the fourth power converter 340 is lower than the frequency of operation of the first power converter 310 . Therefore, a configuration is desired in which the frequency of operation of the first power converter 310 to the fourth power converter 340 is less likely to vary. A specific example of the configuration will be described below.
　図６に示すように、本実施形態に係る制御装置６００は、第１電力変換器３１０から第４電力変換器３４０の各々の稼働の頻度を管理するための稼働履歴データ６２０が記憶されたメモリ６３０を備える。稼働履歴データ６２０は、第１電力変換器３１０から第４電力変換器３４０の各々についての、その電力変換器が稼働状態とされた期間長の累積値である累積稼働期間長を表す。 As shown in FIG. 6, the control device 600 according to the present embodiment includes a memory storing operation history data 620 for managing the frequency of operation of each of the first power converter 310 to the fourth power converter 340. 630. The operation history data 620 represents the cumulative operating period length, which is the cumulative value of the period length during which the power converter is in the operating state, for each of the first power converter 310 to the fourth power converter 340 .
　図７に、本実施形態に係る発熱抑制処理のフローチャートを示す。以下、図７に示す発熱抑制処理の、図３に示した発熱抑制処理との相違点のみを説明する。 FIG. 7 shows a flowchart of heat generation suppression processing according to this embodiment. Only differences between the heat generation suppression process shown in FIG. 7 and the heat generation suppression process shown in FIG. 3 will be described below.
　本実施形態に係る制御装置６００は、必要電力値ＷＸが、１台の稼働電力変換器で出力可能な電力の上限値として予め定められた第１閾値Ｗ１以下である場合（ステップＳ１２；ＹＥＳ）、まず、稼働履歴データ６２０を用いて、第１電力変換器３１０から第４電力変換器３４０の４台の間における稼働期間長の分散の変化が最小となる条件で、それら４台の中から１台を稼働電力変換器として選択する。具体的には、４台のうち最も累積稼働期間長の短いものが稼働電力変換器として選択される。そして、その選択した稼働電力変換器を稼働状態に制御し、残りの３台の非稼働電力変換器を非稼働状態に制御する（ステップＳ２１）。 The control device 600 according to the present embodiment determines that the required power value WX is equal to or less than the first threshold value W1 predetermined as the upper limit value of the power that can be output by one operating power converter (step S12; YES). First, using the operation history data 620, under the condition that the variation in the dispersion of the operation period length among the four power converters 310 to 340 is minimal, Select one as the active power converter. Specifically, the power converter with the shortest cumulative operating period length is selected as the operating power converter among the four units. Then, the selected operating power converter is controlled to be in the operating state, and the remaining three non-operating power converters are controlled to be in the non-operating state (step S21).
　また、本実施形態に係る制御装置６００は、必要電力値ＷＸが、第１閾値Ｗ１よりも大きく（ステップＳ１２；ＮＯ）、かつ２台の稼働電力変換器で出力可能な電力の上限値として予め定められた第２閾値Ｗ２以下である場合（ステップＳ１４；ＹＥＳ）、まず、稼働履歴データ６２０を用いて、第１電力変換器３１０から第４電力変換器３４０の４台の間における稼働期間長の分散の変化が最小となる条件で、それら４台の中から２台を稼働電力変換器として選択する。そして、その選択した２台の稼働電力変換器を稼働状態に制御し、残りの２台の非稼働電力変換器を非稼働状態に制御する（ステップＳ２２）。 In addition, the control device 600 according to the present embodiment sets the required power value WX to be greater than the first threshold value W1 (step S12; NO), and preliminarily sets the upper limit value of the power that can be output by the two operating power converters. If it is equal to or less than the determined second threshold value W2 (step S14; YES), first, using the operation history data 620, the operation period length between the four units of the first power converter 310 to the fourth power converter 340 Two of the four are selected as active power converters under the condition that the change in the variance of is minimal. Then, the selected two operating power converters are controlled to be in the operating state, and the remaining two non-operating power converters are controlled to be in the non-operating state (step S22).
　また、本実施形態に係る制御装置６００は、必要電力値ＷＸが、第２閾値Ｗ２よりも大きく（ステップＳ１４；ＮＯ）、かつ３台の稼働電力変換器で出力可能な電力の上限値として予め定められた第３閾値Ｗ３以下である場合（ステップＳ１６；ＹＥＳ）、まず、稼働履歴データ６２０を用いて、第１電力変換器３１０から第４電力変換器３４０の４台の間における稼働期間長の分散の変化が最小となる条件で、それら４台の中から３台を稼働電力変換器として選択する。そして、その選択した３台の稼働電力変換器を稼働状態に制御し、残りの１台の非稼働電力変換器を非稼働状態に制御する（ステップＳ２３）。 Further, the control device 600 according to the present embodiment sets the required power value WX to be greater than the second threshold value W2 (step S14; NO), and preliminarily sets the upper limit value of the power that can be output by the three operating power converters. If it is equal to or less than the determined third threshold value W3 (step S16; YES), first, using the operation history data 620, the operation period length between the four units of the first power converter 310 to the fourth power converter 340 3 out of the 4 are selected as active power converters under the condition that the change in the variance of is minimal. Then, the selected three operating power converters are controlled to be in the operating state, and the remaining one non-operating power converter is controlled to be in the non-operating state (step S23).
　以上のように、本実施形態では、第１電力変換器３１０から第４電力変換器３４０の４台の間における稼働期間長の分散の変化が最小となる条件で、稼働電力変換器が選択される。このため、第１電力変換器３１０から第４電力変換器３４０の稼働の頻度にばらつきが生じにくい。このことは、電源回路３００の長寿命化に資する。 As described above, in the present embodiment, the operating power converters are selected under the condition that the variation in the dispersion of the operating period lengths among the four power converters from the first power converter 310 to the fourth power converter 340 is minimized. be. Therefore, the frequency of operation of the first power converter 310 to the fourth power converter 340 is less likely to vary. This contributes to prolonging the life of the power supply circuit 300 .
　また、本実施形態に係る制御装置６００は、既述のステップＳ２１、Ｓ２２、Ｓ２３、又はＳ１８の後に、稼働履歴データ６２０を更新する（ステップＳ２４）。つまり、本実施形態に係る制御装置６００は、台数制御を行う度に稼働履歴データ６２０を更新する。このため、次の台数制御において、最新の稼働履歴データ６２０を用いることができる。 Also, the control device 600 according to the present embodiment updates the operation history data 620 (step S24) after step S21, S22, S23, or S18. That is, the control device 600 according to this embodiment updates the operation history data 620 each time the number of machines is controlled. Therefore, the latest operation history data 620 can be used in the next number control.
　また、本実施形態に係る制御装置６００は、ステップＳ２４では、更新後の稼働履歴データ６２０を参照し、第１電力変換器３１０から第４電力変換器３４０の少なくともいずれかの稼働期間長が、予め定められた基準期間長を超過しているか否かを確認する。そして、制御装置６００は、稼働期間長が基準期間長を超過した電力変換装置が存在する場合は、その旨の警告を外部に発する。 Further, in step S24, the control device 600 according to the present embodiment refers to the updated operation history data 620, and the operation period length of at least one of the first power converter 310 to the fourth power converter 340 is It is checked whether or not a predetermined reference period length has been exceeded. Then, when there is a power conversion device whose operating period length exceeds the reference period length, the control device 600 issues a warning to that effect to the outside.
　ここで“外部”とは、具体的には、表示装置８００の稼働を管理する遠隔の管理センタに置かれる端末、表示装置８００に付設される警告灯、その他の警告を保守員に知らせるための報知手段を意味する。 Here, "external" specifically includes a terminal placed in a remote management center that manages the operation of the display device 800, a warning light attached to the display device 800, and other devices for informing maintenance personnel of warnings. Means notification means.
　このようにして外部に警告を発することにより、電源回路３００が故障に至る前に、電源回路３００の保守及び点検を行うことができる。つまり、故障を未然に防止できる。一方、制御装置６００は、稼働期間長が基準期間長を超過した電力変換装置が存在しない場合は、既述のステップＳ１９に進む。 By issuing a warning to the outside in this way, maintenance and inspection of the power supply circuit 300 can be performed before the power supply circuit 300 fails. In other words, failure can be prevented. On the other hand, when there is no power conversion device whose operation period length exceeds the reference period length, the control device 600 proceeds to step S19 described above.
　［実施形態４］
　上記実施形態１－３に係る構成において、表示画面１００ａの輝度の上限値が１日の時間帯に応じて変更されてもよい。以下、その具体例を述べる。 [Embodiment 4]
In the configuration according to Embodiments 1-3, the upper limit value of the brightness of the display screen 100a may be changed according to the time zone of the day. A specific example will be described below.
　図８に示すように、本実実施形態に係る制御装置６００は、まず、表示画面１００ａの輝度を変更する時刻として予め定められた輝度変更時刻が到来したか否かを判定する（ステップＳ３１）。本実施形態では、輝度変更時刻は、午前５時、午前１０時、午後３時、及び午後７時とする。 As shown in FIG. 8, the control device 600 according to this embodiment first determines whether or not a brightness change time predetermined as a time to change the brightness of the display screen 100a has arrived (step S31). . In this embodiment, the brightness change times are 5:00 am, 10:00 am, 3:00 pm, and 7:00 pm.
　以下の説明中、“早朝”とは、午前５時から午前１０時までの期間を指す。“昼間”とは、午前１０時から午後３時までの期間を指す。“夕方”とは、午後３時から午後７時までの期間を指す。“夜間”とは、午後７時から午前５時までの期間を指す。 In the following explanation, "early morning" refers to the period from 5:00 am to 10:00 am. "Daytime" refers to the period from 10:00 am to 3:00 pm. "Evening" refers to the period from 3:00 pm to 7:00 pm. "Night" refers to the period from 7:00 pm to 5:00 am.
　表示装置８００が設置される屋外において、夜間は、昼間に比べると太陽光による照度が低下するので、表示画面１００ａのコントラストが高められ、表示画面１００ａが視認しやすくなる。このため、夜間は、表示画面１００ａの輝度を低下させても差し支え無い。 In the outdoors where the display device 800 is installed, the illuminance of the sunlight is lower at night than in the daytime, so the contrast of the display screen 100a is increased and the display screen 100a is easier to see. Therefore, at night, the brightness of the display screen 100a may be lowered.
　そこで、夜間が到来した場合、つまり、ステップＳ３１で輝度変更時刻としての午後７時が到来した場合（ステップＳ３１；ＹＥＳ）、制御装置６００は、表示画面１００ａの全画素についての輝度の上限値を、昼間の場合の上限値よりも６割低下させた値に変更する（ステップＳ３２）。 Therefore, when nighttime arrives, that is, when 7:00 pm as the brightness change time arrives in step S31 (step S31; YES), the control device 600 sets the upper limit value of the brightness of all the pixels of the display screen 100a to , to a value that is 60% lower than the upper limit value for daytime (step S32).
　また、制御装置６００は、夜間においては、同じ映像データを表示画面１００ａに表示させる場合でも各画素の輝度の瞬時値が昼間よりも６割削減される条件で、映像データが表す任意の輝度値を、昼間よりも６割低下させた値に補正する。 In addition, even when the same video data is displayed on the display screen 100a at night, the control device 600 can set any brightness value represented by the video data under the condition that the instantaneous value of the brightness of each pixel is reduced by 60% compared to the daytime. is corrected to a value that is 60% lower than that in the daytime.
　また、早朝及び夕方も同様に、昼間に比べると表示画面１００ａが視認しやすいため、表示画面１００ａの輝度を抑えることができる。 In addition, since the display screen 100a is easier to see in the early morning and evening than in the daytime, the brightness of the display screen 100a can be suppressed.
　そこで、早朝又は夕方が到来した場合、つまり、ステップＳ３１で輝度変更時刻としての午前５時又は午後７時が到来した場合（ステップＳ３１；ＹＥＳ）、制御装置６００は、表示画面１００ａの全画素についての輝度の上限値を、昼間の場合の上限値よりも４割低下させた値に変更する（ステップＳ３２）。 Therefore, when early morning or evening arrives, that is, when 5:00 am or 7:00 pm as the brightness change time arrives in step S31 (step S31; YES), the control device 600 controls all pixels of the display screen 100a. is changed to a value that is 40% lower than the upper limit value for daytime (step S32).
　また、制御装置６００は、早朝及び夕方においては、同じ映像データを表示画面１００ａに表示させる場合でも各画素の輝度の瞬時値が昼間よりも４割削減される条件で、映像データが表す任意の輝度値を、昼間よりも４割低下させた値に補正する。 In addition, in the early morning and in the evening, even when the same video data is displayed on the display screen 100a, the control device 600 can reduce the instantaneous value of the brightness of each pixel by 40% compared to the daytime. The brightness value is corrected to a value that is 40% lower than that in the daytime.
　一方、制御装置６００は、輝度変更時刻がまだ到来していない場合（ステップＳ３１；ＮＯ）、又はステップＳ３２で輝度の上限値を変更した後は、既述の台数制御を行う（ステップＳ３３）。具体的には、ステップＳ３３は、図３のステップＳ１１からステップＳ１８までの処理、又は図７のステップＳ１１からステップＳ２４までの処理を指す。 On the other hand, if the brightness change time has not yet arrived (step S31; NO), or after changing the upper limit value of brightness in step S32, the controller 600 performs the above-described number control (step S33). Specifically, step S33 refers to the process from step S11 to step S18 in FIG. 3 or the process from step S11 to step S24 in FIG.
　次に、制御装置６００は、表示器１００での映像の表示を終了する場合は（ステップＳ１９；ＹＥＳ）、本発熱抑制処理を終了する。一方、制御装置６００は、表示器１００での映像の表示を継続する場合は（ステップＳ１９；ＮＯ）、再びステップＳ３１に戻り、同様の処理を繰り返す。 Next, when the control device 600 ends the display of the image on the display device 100 (step S19; YES), the heat generation suppression process ends. On the other hand, if control device 600 continues to display the image on display 100 (step S19; NO), control device 600 returns to step S31 and repeats the same processing.
　以上のように、本実施形態では、制御装置６００が、１日の時間帯に応じて表示画面１００ａの輝度の上限値を変更する。この結果、表示器１００での消費電力を低減させることができ、かつ電源回路３００での発熱を一層抑制することができる。 As described above, in this embodiment, the control device 600 changes the upper limit value of the brightness of the display screen 100a according to the time period of the day. As a result, the power consumption in the display device 100 can be reduced, and heat generation in the power supply circuit 300 can be further suppressed.
　以上、実施形態１－４について説明した。以下に述べる変形も可能である。 Embodiments 1-4 have been described above. Variations described below are also possible.
　上記実施形態１では、道路の近傍に設置され、道路情報を表示する表示装置８００を例示したが、表示装置８００は、競技場、公共施設、建物の壁面等に設置され、競技の実況、案内、広告等を表示するものであってもよい。また、図１には、表示器１００と機器収容箱７１０とが分離した構成を例示したが、表示器１００と、給電部２００、電源回路３００、開閉器群４００、中継器５００、及び制御装置６００とが、共通のフレーム内に収められていてもよい。 In the first embodiment, the display device 800 is installed near a road and displays road information. , advertisements, etc. may be displayed. In addition, FIG. 1 illustrates a configuration in which the display 100 and the device housing box 710 are separated, but the display 100, the power supply unit 200, the power supply circuit 300, the switch group 400, the repeater 500, and the control device 600 may be contained within a common frame.
　また、上記実施形態１では、表示画面１００ａに表示させる動画のフレームレートとして、０．５Ｈｚ以上、５Ｈｚ以下という数値を例示したが、この値に限られない。フレームレートは２４Ｈｚ以上、具体的には、２４Ｈｚ、３０Ｈｚ、５０Ｈｚ、又は６０Ｈｚであってもよい。 In addition, in the above-described Embodiment 1, numerical values of 0.5 Hz or more and 5 Hz or less were exemplified as the frame rate of the moving image to be displayed on the display screen 100a, but the values are not limited to these values. The frame rate may be 24 Hz or higher, specifically 24 Hz, 30 Hz, 50 Hz, or 60 Hz.
　また、上記実施形態１では、台数制御の繰り返し周波数が動画のフレームレートに等しい場合を例示したが、台数制御の繰り返し周波数とフレームレートとは必ずしも等しくなくてもよい。一般に、動画のフレームレートをｆ、自然数をｎとしたとき、ｆ／ｎで表される繰り返し周波数で、台数制御を繰り返し行ってもよい。 Also, in the first embodiment, the case where the repetition frequency of the number control is equal to the frame rate of the moving image has been exemplified, but the repetition frequency and the frame rate of the number control may not necessarily be equal. In general, when the frame rate of a moving image is f and the natural number is n, the number control may be repeatedly performed at a repetition frequency expressed by f/n.
　図２に示した電圧降下部５１０の構成は特に限定されない。電圧降下部５１０は、１つ又は複数のＤＣ（direct current）／ＤＣコンバータ（DC to DC converter）その他の、変圧器を含む電圧降下回路によって構成することができる。電圧降下部５１０を、並列接続された複数の電圧降下回路によって構成する場合は、電圧降下部５１０を１つの電圧降下回路によって構成する場合に比べると、各々の電圧降下回路を軽量に構成でき、かつ複数の電圧降下回路を分離して配置することができる。このため、電圧降下部５１０の荷重が狭い領域に集中してしまうことを回避できる。従って、電圧降下部５１０を支持する部材を高剛性に形成する必要がなくなるので、電圧降下部５１０を支持する部材の軽量化が図られる。 The configuration of the voltage drop unit 510 shown in FIG. 2 is not particularly limited. The voltage drop unit 510 may be configured by one or more direct current/DC converters (DC to DC converters) or other voltage drop circuits including transformers. When the voltage drop section 510 is composed of a plurality of voltage drop circuits connected in parallel, each voltage drop circuit can be made lighter than when the voltage drop section 510 is composed of a single voltage drop circuit. Moreover, a plurality of voltage drop circuits can be arranged separately. Therefore, it is possible to avoid concentration of the load of the voltage drop portion 510 on a narrow region. Therefore, the member supporting the voltage drop portion 510 does not need to be formed with high rigidity, so that the weight of the member supporting the voltage drop portion 510 can be reduced.
　但し、中継器５００は、電圧降下部５１０を備えなくてもよい。つまり、中継器５００は、電源回路３００から出力された直流電圧をそのまま表示器１００に供給してもよい。
中継器５００が電圧降下部５１０を備えない場合は、中継器５００の軽量化が図られる。 However, the repeater 500 does not have to include the voltage drop section 510 . That is, the repeater 500 may supply the direct-current voltage output from the power supply circuit 300 to the display device 100 as it is.
When the repeater 500 does not include the voltage drop section 510, the weight of the repeater 500 can be reduced.
　上記実施形態では、表示器１００が備える発光装置が発光ダイオードである場合を例示したが、発光装置は、有機エレクトロルミネッセンスを生じる素子によって可視光を放射するものであってもよい。 In the above embodiment, the case where the light-emitting device included in the display 100 is a light-emitting diode was exemplified, but the light-emitting device may emit visible light from an element that produces organic electroluminescence.
　本開示は、本開示の広義の精神と範囲を逸脱することなく、様々な実施形態及び変形が可能とされる。また、上述した実施形態は、本開示を説明するためのものであり、本開示の範囲を限定するものではない。本開示の範囲は、実施形態ではなく、請求の範囲によって示される。請求の範囲内及びそれと同等の開示の意義の範囲内で施される様々な変形が、本開示の範囲内とみなされる。 Various embodiments and modifications of the present disclosure are possible without departing from the broad spirit and scope of the present disclosure. Moreover, the embodiments described above are for explaining the present disclosure, and do not limit the scope of the present disclosure. The scope of the present disclosure is indicated by the claims rather than the embodiments. Various modifications that come within the scope of the claims and the equivalents of the meaning of the disclosure are considered to be within the scope of the present disclosure.
　１００…表示器、１００ａ…表示画面、１１０…第１表示ユニット、１２０…第２表示ユニット、１３０…第３表示ユニット、１４０…第４表示ユニット、２００…給電部、３００…電源回路、３１０…第１電力変換器、３２０…第２電力変換器、３３０…第３電力変換器、３４０…第４電力変換器、３５１…１次回路、３５１ａ…平滑化用キャパシタ、３５２…２次回路、３５３…変圧器、３５４…スイッチング素子、４００…開閉器群、４１０…第１開閉器、４２０…第２開閉器、４３０…第３開閉器、４４０…第４開閉器、５００…中継器、５１０…電圧降下部、６００…制御装置、６１０…バッファメモリ、６２０…稼働履歴データ、６３０…メモリ、７１０…機器収容箱、７２０…支柱、７３０…電力配線、７４０…データ配線、８００…表示装置、９００…表示装置、９１０…制御装置、ＶＤ…映像配信センタ。 DESCRIPTION OF SYMBOLS 100... Indicator 100a... Display screen 110... 1st display unit 120... 2nd display unit 130... 3rd display unit 140... 4th display unit 200... Power supply part 300... Power supply circuit 310... First power converter 320 Second power converter 330 Third power converter 340 Fourth power converter 351 Primary circuit 351a Smoothing capacitor 352 Secondary circuit 353 Transformer 354 Switching element 400 Switch group 410 First switch 420 Second switch 430 Third switch 440 Fourth switch 500 Repeater 510 Voltage drop unit 600 Control device 610 Buffer memory 620 Operation history data 630 Memory 710 Equipment storage box 720 Support 730 Power wiring 740 Data wiring 800 Display device 900 ... display device, 910 ... control device, VD ... video distribution center.

Claims (8)

  1. 　映像が表示される表示画面を構成する複数の表示ユニットを有し、前記表示画面に前記映像を表示するために必要な電力の大きさが変化する表示器と、
    　交流電力を供給する給電部に対して並列に接続された複数台の電力変換器を有し、各々の前記電力変換器が前記交流電力を直流電力に変換する電源回路と、
    　前記表示画面に前記映像を表示するために必要な電力の大きさを表す必要電力値を求め、求めた前記必要電力値に基づいて、前記必要電力値が小さいほど、前記電源回路を構成する複数台の前記電力変換器のうち稼働させる前記電力変換器である稼働電力変換器の台数が減少する条件で、前記稼働電力変換器の台数を決定し、決定した台数の前記稼働電力変換器を、前記直流電力を出力する稼働状態とし、前記電源回路を構成する複数台の前記電力変換器のうち前記稼働電力変換器以外の前記電力変換器である非稼働電力変換器を、前記直流電力の出力を断つ非稼働状態とする台数制御を行う制御装置と、
    　前記稼働電力変換器によって出力された前記直流電力を、前記表示器を構成する複数の前記表示ユニットに分配する中継器と、
    　を備える、表示装置。     a display device having a plurality of display units forming a display screen on which an image is displayed, wherein the amount of power required to display the image on the display screen varies;
    A power supply circuit having a plurality of power converters connected in parallel to a power supply unit that supplies AC power, each of the power converters converting the AC power into DC power;
    A required power value representing the magnitude of the power required to display the image on the display screen is obtained, and based on the obtained required power value, the smaller the required power value, the more the plurality of power supply circuits constituting the power supply circuit. determining the number of the operating power converters under the condition that the number of the operating power converters that are the power converters to be operated among the power converters of the set decreases, and using the determined number of the operating power converters, setting a non-operating power converter, which is the power converter other than the operating power converter among the plurality of power converters constituting the power supply circuit, to an operating state in which the DC power is output, and outputting the DC power. A control device that controls the number of units in a non-operating state that cuts off the
    a repeater that distributes the DC power output by the operating power converter to a plurality of the display units that constitute the display;
    A display device.
  2. 　前記電力変換器ごとに設けられた開閉器を有し、各々の前記開閉器が、該開閉器が設けられた前記電力変換器を前記給電部と導通させる導通状態と、該開閉器が設けられた前記電力変換器を前記給電部から切り離す遮断状態とに切り換えが可能な開閉器群、
    　をさらに備え、
    　前記制御装置が、前記台数制御において、前記稼働電力変換器に対して設けられた前記開閉器を前記導通状態とする一方、前記非稼働電力変換器に対して設けられた前記開閉器は前記遮断状態とする、
    　請求項１に記載の表示装置。     a switch provided for each of the power converters, wherein each switch is in a conductive state in which the power converter provided with the switch is electrically connected to the power supply unit; A switch group capable of switching between a cutoff state in which the power converter is cut off from the power supply unit,
    further comprising
    In the number control, the control device places the switches provided for the operating power converters in the conducting state, while the switches provided for the non-operating power converters switch to the cut-off state. to state,
    The display device according to claim 1.
  3. 　各々の前記電力変換器が、前記交流電力を前記直流電力に変換するためにスイッチング動作を行うスイッチング素子を有し、
    　前記制御装置が、前記台数制御において、前記稼働電力変換器の前記スイッチング素子に前記スイッチング動作を行わせる一方、前記非稼働電力変換器の前記スイッチング素子には前記スイッチング動作を停止させる、
    　請求項１に記載の表示装置。     each of the power converters has a switching element that performs a switching operation to convert the AC power to the DC power;
    In the number control, the control device causes the switching elements of the operating power converters to perform the switching operations, while causing the switching elements of the non-operating power converters to stop the switching operations.
    The display device according to claim 1.
  4. 　前記映像が動画であり、
    　前記制御装置が、前記動画のフレームレートをｆ、自然数をｎとしたとき、ｆ／ｎで表される繰り返し周波数で、前記台数制御を繰り返し行う、
    　請求項１から３のいずれか１項に記載の表示装置。     the video is a video,
    The control device repeats the number control at a repetition frequency represented by f / n, where f is the frame rate of the moving image and n is a natural number.
    The display device according to any one of claims 1 to 3.
  5. 　前記制御装置が、前記台数制御において、各々の前記電力変換器についての、該電力変換器が前記稼働状態とされた期間長の累積値である累積稼働期間長を表す稼働履歴データを用いて、複数の前記電力変換器の間における前記累積稼働期間長のばらつきが抑制される条件で、複数の前記電力変換器の中から前記稼働電力変換器を選択する、
    　請求項１から４のいずれか１項に記載の表示装置。     The control device, in the number control, uses the operation history data representing the cumulative operating period length, which is the cumulative value of the period length during which the power converter is in the operating state, for each of the power converters, Selecting the operating power converter from among the plurality of power converters under a condition that variation in the cumulative operating period length among the plurality of power converters is suppressed;
    The display device according to any one of claims 1 to 4.
  6. 　前記制御装置が、複数の前記電力変換器の少なくともいずれかの前記累積稼働期間長が、予め定められた基準期間長を超過する場合に、その旨の警告を発する、
    　請求項５に記載の表示装置。     When the cumulative operation period length of at least one of the plurality of power converters exceeds a predetermined reference period length, the control device issues a warning to that effect.
    The display device according to claim 5.
  7. 　前記制御装置が、１日の時間帯に応じて前記表示画面の輝度の上限値を変更する、
    　請求項１から６のいずれか１項に記載の表示装置。     The control device changes the upper limit value of the brightness of the display screen according to the time of day.
    The display device according to any one of claims 1 to 6.
  8. 　前記中継器が、
    　前記稼働電力変換器によって出力された前記直流電力を安定化させる電圧降下部、
    　を有する、請求項１から７のいずれか１項に記載の表示装置。     the repeater
    a voltage drop unit for stabilizing the DC power output by the working power converter;
    8. The display device according to any one of claims 1 to 7, comprising:
PCT/JP2021/003912 2021-02-03 2021-02-03 Display device WO2022168200A1 (en)

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