Composite display device and control method thereof

Abstract

The present technology relates to a composite display device that has achieved both power supply size reduction and low cost, and a method for controlling the same, the composite display device comprising a plurality of display devices each having a power supply. The composite display device is provided with a plurality of display devices each having a power supply with a predetermined supply power, and a power supply connecting unit connecting the power supplies of the plurality of display devices in parallel. The composite display device is configured such that, when at least one display device of the plurality of display devices requires power exceeding a predetermined supply power of the power supply of the one display device, power can be supplied from the power supply of another display device. The present technology may be applied, for example, to a multi-display device.

Description

[Technical field]

[0001] The present technology relates to a composite display device and a control method thereof, and in particular to a composite display device including a plurality of display devices each equipped with a power supply, which makes it possible to realize a smaller and less costly power supply, and a control method thereof. [Background technology]

[0002] 2. Description of the Related Art There is known a multi-display device in which a large screen formed by arranging a plurality of display devices adjacent to each other is used as a single display device to display one image (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-188524 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above multi-display device, the power consumption of each adjacent display device is not necessarily the same. Even if it is known that each display device will not operate simultaneously at the maximum load that each can consume, it is necessary to provide a power supply device that can handle the maximum load. Therefore, when a group of multiple display devices is viewed as a single device, it has a redundant power supply for the maximum load that the device can consume.

[0005] The present technology has been made in view of the above circumstances, and makes it possible to realize a smaller and less costly power supply in a composite display device made up of a plurality of display devices, each of which is equipped with a power supply. [Means for solving the problem]

[0006] A composite display device according to one aspect of the present technology comprises a plurality of display devices, each having a power supply with a predetermined supply power, and a power supply connection section that connects the power supplies of the plurality of display devices in parallel, and is configured such that when at least one of the plurality of display devices requires power that exceeds the predetermined supply power of the power supply of that display device, power is supplied from the power supply of the other display devices.

[0007] A control method for a composite display device according to one aspect of the present technology is a control method for a composite display device including a plurality of display devices, each having a power supply with a predetermined supply power, and a power supply connection section that connects the power supplies of the plurality of display devices in parallel, wherein when a first display device of the plurality of display devices requires power that exceeds the predetermined supply power of the power supply of the display device, a second display device of the plurality of display devices supplies power to the first display device.

[0008] In one aspect of the present technology, in a composite display device comprising a plurality of display devices, each having a power supply with a predetermined supply power, and a power supply connection section that connects the power supplies of the plurality of display devices in parallel, when a first display device of the plurality of display devices requires power that exceeds the predetermined supply power of the power supply of the display device, power is supplied from a second display device of the plurality of display devices to the first display device.

[0009] The composite display device may be an independent device or may be an internal block constituting a single device. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of an image display on a multi-display device. [Diagram 2]FIG. 1 is a block diagram showing an example of the configuration of a general multi-display device as a comparative example. [Diagram 3] FIG. 11 is a diagram showing the relationship between light emission luminance and power consumption of a single display device. [Figure 4] FIG. 11 is a diagram showing the relationship between light emission luminance and power consumption in the entire multi-display device. [Diagram 5] 1A and 1B are diagrams illustrating an example of an image display generated on a multi-display device of a comparative example. [Figure 6] 1A to 1C are diagrams illustrating examples of video display by a multi-display device to which the present technology is applied. [Figure 7] 1 is a block diagram showing an example of the configuration of a multi-display device to which the present technology is applied. [Figure 8] FIG. 8 is a diagram showing a detailed first configuration example of the multi-display device of FIG. [Figure 9] 1 is a diagram showing the relationship between a differential voltage that is the output of a voltage error amplifier and a current value flowing through a MOS-FET. [Figure 10] FIG. 8 is a diagram showing a second detailed configuration example of the multi-display device of FIG. [Figure 11] FIG. 1 is a block diagram showing an example of the configuration of a composite apparatus made up of two apparatuses. [Figure 12] FIG. 1 is a block diagram showing an example of the configuration of a composite device made up of four devices. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a description will be given of an embodiment of the present technology with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and duplicated description will be omitted. The description will be given in the following order. 1. Functions realized by multi-display devices using this technology 2. Block diagram of a multi-display device using this technology 3. First Configuration Example of Multi-Display Device 4. Second Configuration Example of Multi-Display Device 5. Example of a composite device using this technology

[0012] <1. Functions realized by a multi-display device using this technology> The present technology can be applied, for example, to a multi-display device (composite display device) that displays a predetermined image by coordinating a plurality of display devices.

[0013] Therefore, functions realized by a multi-display device to which the present technology is applied will be described with reference to FIGS.

[0014] First, a typical multi-display device will be described as a comparative example, and then functions realized by a multi-display device to which the present technology is applied will be described.

[0015] A multi-display device is a device that is composed of multiple display devices arranged adjacently in at least one of the vertical or horizontal directions, and displays a single image on the large screen created by the multiple display devices combined as a single display device.

[0016] For example, if a multi-display device is composed of four display devices arranged in a 2x2 configuration, the multi-display device displays the image 11 shown in A of Figure 1 by having the four display devices respectively display images 11RA, 11LA, 11RB, and 11LB of B of Figure 1.

[0017] FIG. 2 is a block diagram showing an example of the configuration of a general multi-display device that is capable of displaying the image 11 shown in FIG.

[0018] The multi-display device 21 in FIG. 2 is made up of four display devices 22RA, 22LA, 22RB, and 22LB.

[0019] The four display devices 22RA, 22LA, 22RB, and 22LB are the same display device 22, and have a power supply 23 and a display 24. The power supply 23 and the display 24 of each of the display devices 22RA, 22LA, 22RB, and 22LB are denoted by the same reference numerals and will be referred to as power supply 23RA and display 24RA, power supply 23LA and display 24LA, power supply 23RB and display 24RB, and power supply 23LB and display 24LB.

[0020] The display 24RA of the display device 22RA arranged at the upper right displays the video 11RA, and the display 24LA of the display device 22LA arranged at the upper left displays the video 11LA. The display 24RB of the display device 22RB arranged at the lower right displays the video 11RB, and the display 24LB of the display device 22LB arranged at the lower left displays the video 11LB.

[0021] Each display device 22 constituting the multi-display device 21 has its own power supply 23 that supplies the power necessary to drive the display 24. Here, the maximum power that the power supply 23 of each display device 22 can supply is set to 100 W, and the maximum luminance B when the entire surface of the display 24 is caused to emit light is set to 100 (B=100).

[0022] FIG. 3 is a diagram showing the relationship between the light emission luminance and the power consumption of the display device 22 alone.

[0023] As shown in A of FIG. 3, when the display 24 does not emit light, the luminance B of the display 24 is 0, and the power consumption is 0 W.

[0024] As shown in FIG. 3B, when one half of the display 24 is illuminated at maximum brightness B=100 and the other half is not illuminated (brightness B=0), the power consumption is 50W.

[0025] Furthermore, as shown in FIG. 3C, when the entire surface of the display 24 is illuminated at half brightness B=50, the power consumption is also 50W.

[0026] As shown in FIG. 3D, when the entire surface of the display 24 is illuminated with maximum brightness B=100, the power consumption is 100W.

[0027] Also, as shown in FIG. 3E, if the display area of ​​the display 24 is limited to 1 / 4 and a maximum power of 100 W is used, it is possible to emit light at a brightness B=400, which is four times that of full-surface illumination.

[0028] FIG. 4 is a diagram showing the relationship between the light emission luminance and the power consumption of the entire multi-display device 21 made up of the four display devices 22. In FIG.

[0029] Since the multi-display device 21 is configured by arranging identical display devices 22 in a 2x2 configuration, each of the four display devices 22 is capable of displaying images with the individual display capabilities described in FIG.

[0030] For example, as shown in A of FIG. 4, each of the four display devices 22 can emit light over the entire surface of the display 24 at maximum brightness B=100.

[0031] For example, as shown in B of FIG. 4, three display devices 22 can illuminate the entire surface of the display 24 at a maximum brightness B=100, and one display device 22 can illuminate 1 / 4 of the display area of ​​the display 24 at a brightness B=400, which is four times the brightness when the entire surface is illuminated.

[0032] Also, for example, as shown in C of FIG. 4, all four display devices 22 can illuminate 1 / 4 of the display area of ​​the display 24 at a brightness B=400, which is four times the brightness when the entire screen is illuminated, and illuminate the central display area, which is 1 / 4 of the large screen, at a high brightness B=400.

[0033] Even if four display devices 22 are combined to display an image in this way, the relationship between the light emission luminance and power consumption of each display device 22 is determined as described with reference to FIG.

[0034] Therefore, for example, when an image that illuminates 1 / 4 of the display area of ​​a large screen at high brightness B=400 as shown in A of FIG. 5 is moved to the display 24LA side of the display device 22LA as shown in B of FIG. 5, the display area covered by the display 24LA exceeds 1 / 4, and therefore the illumination at high brightness B=400 cannot be maintained as shown in C of FIG. 5, and the illumination drops to the brightness B that can be illuminated with a maximum power of 100W per unit. For example, the brightness B of the display area of ​​the display 24LA drops to 200 (B=200). On the other hand, the displays 24RA, 24RB, and 24LB that are covered by the display area narrower than 1 / 4 can illuminate within a range not exceeding the maximum power of 100W, and the illumination brightness B increases to 500 (B=500), 1000 (B=1000), and 500 (B=500), respectively.

[0035] In this way, in a typical multi-display device 21, since the light emission capability of each display device 22 is fixed, even if multiple display devices 22 are combined, a breakdown in display luminance occurs depending on the balance of the images displayed by each display device 22. When displaying moving images, it is quite possible that the display object requiring high luminance is not limited to the center of the large screen in Fig. 5, but moves within the large screen as in Fig. 5C. When the display area of ​​the image is biased as in Fig. 5C, the multi-display device 21 prevents a breakdown in display luminance by, for example, adjusting the luminance of displays 24RA, 24RB, and 24LB to the maximum luminance B=200 of display 24LA.

[0036] In contrast, Fig. 6 shows an example of a large-screen image display by a multi-display device 41 to which the present technology is applied, which will be described later with reference to Fig. 7. However, the reference numerals of the displays in Fig. 6 match the reference numerals of the multi-display device 21.

[0037] FIG. 6A shows a display example in which the same image as FIG. 5C is displayed on a multi-display device 41, which will be described later.

[0038] As shown in C of Fig. 5, even if the display area covered by display 24LA exceeds ¼, multi-display device 41 can cause display 24LA to emit light at high brightness B=400 as shown in A of Fig. 6 by receiving power from other displays 24RA, 24RB, and 24LB which have smaller display areas. Since displays 24RA, 24RB, and 24LB also have display areas smaller than ¼, they can emit light at high brightness B=400. As a result, it becomes possible to display ¼ of the display area of ​​the large screen as a whole across the four screens with light emitted at high brightness B=400.

[0039] For example, as shown in B of FIG. 6, the multi-display device 41 can also illuminate the entire surface of display 24LA at four times the brightness B=400 by not illuminating the three displays 24RA, 24RB, and 24LB and supplying their power to the remaining display 24LA instead.

[0040] Furthermore, when the display area of ​​the multi-display device 41 is limited to 1 / 4 of the display area of ​​one display 24LA, as shown in C of FIG. 6, the multi-display device 41 can emit light at a brightness B=1600, which is 16 times that of when the entire display 24LA is illuminated.

[0041] In this way, the multi-display device 41 described below regards the power of the power sources of multiple display devices operating in conjunction with each other as a single power source, and is equipped with a power sharing function that allocates power to each display device as needed, making it possible to achieve high-brightness displays that cannot be achieved with the multi-display device 21 described above.

[0042] 6 shows an example in which the number of display devices constituting multi-display device 41 is four, but the number of display devices is not limited to four. For example, when the number of display devices constituting multi-display device 41 is N (N>1) and light emission is concentrated on the entire surface of one display as in B of FIG. 6, a display with light emission brightness N times that of a single display device is possible. Also, when the number of display devices constituting multi-display device 41 is N (N>1) and light emission is concentrated on a display area of ​​1 / M (M>1) of only one of the display devices, a display with light emission brightness N×M times that of a single display device is possible.

[0043] A specific configuration of the multi-display device with the power share function shown in FIG. 6 will now be described.

[0044] <2. Block diagram of a multi-display device to which this technology is applied> FIG. 7 is a block diagram showing an example of the configuration of a multi-display device to which the present technology is applied.

[0045] In FIG. 7, for simplicity, an example in which a multi-display device is configured with two display devices will be described, but the same can be applied to a case in which three or more display devices are used.

[0046] 7 is composed of two display devices 42 arranged adjacent to each other in the vertical or horizontal direction. In order to distinguish between the two display devices 42, one display device 42 will be referred to as display device 42A, and the other display device 42 will be referred to as display device 42B.

[0047] Display device 42 has a power supply 51, a power supply control circuit 52, and a display 53. Thus, display device 42A has a power supply 51A, a power supply control circuit 52A, and a display 53A, and display device 42B has a power supply 51B, a power supply control circuit 52B, and a display 53B.

[0048] The power supply 51 (51A, 51B) has the ability to supply a predetermined amount of power, and supplies the required predetermined amount of power to a display 53 as a load via a power supply line 54 (54A, 54B).

[0049] The power supply control circuit 52 (52A, 52B) controls the power supply from the power supply 51 to the display 53.

[0050] Display 53 (53A, 53B) receives power from power source 51 and displays a predetermined image based on a video signal input via a signal line (not shown). In this embodiment, display 53A and display 53B have the same screen size.

[0051] A power supply line 54A connecting the power supply 51A and the display 53A in the display device 42A and a power supply line 54B connecting the power supply 51B and the display 53B in the display device 42B are connected by a power supply connection line 55. The power supply connection line 55 is a power supply connection section that connects the power supply 51A of the display device 42A and the power supply 51B of the display device 42B in parallel.

[0052] In the multi-display device 41 configured as above, the output of each power supply 51 is controlled so that the power supply to each of the two display devices 42 from the power supplies 51 is balanced.

[0053] The power supply 51 provided in each of the display devices 42 is a power supply with a supply capacity smaller than the maximum power consumed by the display device itself. For example, the display device 42 at the upper left of B and C in Fig. 6 can display an image with four times the brightness B=400 or 16 times the brightness B=160 using 400 W of power, but the power supply 51 provided therein is a power supply with a supply capacity of 100 W, which is smaller than 400 W.

[0054] When display device 42A requires power that exceeds the supply capacity of its own power supply 51A, i.e., when displaying images at a brightness higher than the brightness corresponding to the maximum power supply (100 W) of power supply 51A, power is supplied from power supply 51B of other display device 42B.

[0055] Load A of display 53A and load B of display 53B change depending on the image displayed on each, but the power supplied by each of power sources 51A and 51B is the average value of load A and load B (A+B) / 2.

[0056] <3. First Configuration Example of Multi-Display Device> FIG. 8 shows a detailed first configuration example of the multi-display device 41 of FIG.

[0057] As described above, the display device 42A includes a power supply 51A, a power supply control circuit 52A, and a display 53A.

[0058] The power supply control circuit 52A includes a voltage error amplifier 71A, a bidirectional switch 72A, a current mode PWM controller 73A, a converter 74A, resistors 75A and 76A, and a target voltage generating unit 77A.

[0059] The converter 74A receives a first voltage V E _A(Power supply voltage V E _A) based on a PWM (Pulse Width Modulation) signal from a current mode PWM controller 73A to generate a second voltage V O Specifically, the converter 74A includes an inductor 81A, a MOS-FET 82A, a resistor 83A, a diode 84A, and a capacitor 85A, and outputs a first voltage V E to a second voltage V OHere, the inductance of the inductor 81A is La, the accumulated charge of the parasitic capacitance of the MOS-FET 82A is Qa, and the resistance value of the resistor 83A is Ra.

[0060] The display device 42B is configured similarly to the display device 42A, and therefore a description thereof will be omitted. The converter 74B converts the first voltage V E _B(Power supply voltage V E _B) to the second voltage V O The inductor 81B has an inductance Lb, the charge stored in the parasitic capacitance of the MOS-FET 82B is Qb, and the resistor 83B has a resistance value Rb.

[0061] When the screen sizes of displays 53A and 53B are the same, the inductances La and Lb of inductors 81A and 81B are set to the same (La=Lb), and the resistances Ra and Rb of resistors 83A and 83B are also set to the same (Ra=Rb).

[0062] 7, one of the two display devices 42A and 42B operates as a master that controls the power supply of all power sources 51 of the multi-display device 41, and the other operates as a slave under the control of the master. When the multi-display device 41 is composed of three or more display devices 42, one predetermined display device 42 operates as the master, and the remaining display devices 42 operate as slaves.

[0063] The multi-display device 41 includes at least one master / slave signal generating unit 91 and one power supply control unit 92. The master / slave signal generating unit 91 and the power supply control unit 92 may be provided separately from the multiple display devices 42, or may be provided in each display device 42, for example, so that the master / slave signal generating unit 91 and the power supply control unit 92 of the display device 42 operating as the master are set to be enabled and operate. In the present embodiment, the master / slave signal generating unit 91 and the power supply control unit 92 of the display device 42A are set to be enabled and operate.

[0064] The master / slave signal generating unit 91 generates a master / slave signal that controls whether the power supply control circuit 52 of each display device 42 operates as a master or as a slave, and supplies the signal to the power supply control circuit 52 of each display device 42.

[0065] In this embodiment, display device 42A operates as a master and display device 42B operates as a slave, so that a master signal is supplied to power supply control circuit 52A of display device 42A and a slave signal is supplied to power supply control circuit 52B of display device 42B.

[0066] The supply power control unit 92 calculates the target voltage Vref required for images to be displayed on all displays 53 of the multi-display device 41, and supplies it to the target voltage generation unit 77A. For example, when images to be displayed on all displays 53 are dark images, the displays are made to emit light with low emission luminance, so the target voltage Vref is small. On the other hand, when images to be displayed on all displays 53 are bright images, the displays are made to emit light with high emission luminance, so the target voltage Vref is large.

[0067] The master / slave signal output from the master / slave signal generating unit 91 is supplied to the bidirectional switch 72 of the power supply control circuit 52 of each display device 42. The bidirectional switch 72 is composed of two N-channel MOS-FETs connected in a so-called back-to-back configuration, and the master / slave signal is supplied to the gate of the N-channel MOS-FET. The master signal indicating that the power supply control circuit 52 operates as a master is a High signal that turns on the bidirectional switch 72, and is supplied to the bidirectional switch 72A. The slave signal indicating that the power supply control circuit 52 operates as a slave is a Low signal that turns off the bidirectional switch 72, and is supplied to the bidirectional switch 72B.

[0068] In the power supply control circuit 52A of the display device 42A in which the bidirectional switch 72A is turned on, the output of the voltage error amplifier 71A is made valid. On the other hand, in the power supply control circuit 52B of the display device 42B in which the bidirectional switch 72B is turned off, the output of the voltage error amplifier 71B is made invalid. This prevents interference between the outputs of the voltage error amplifiers 71A and 71B.

[0069] The bidirectional switch 72 is not limited to a configuration of two MOS-FETs connected back-to-back, but may have any configuration that can turn on and off the output in both directions.

[0070] A first input of the voltage error amplifier 71A receives a second voltage V, which is the output voltage of the converter 74A. O A value obtained by dividing _A by resistors 75A and 76A is input as a first input voltage V'(A). A target voltage Vref generated by a target voltage generating unit 77A is input as a second input voltage Vref to a second input of the voltage error amplifier 71A. The target voltage generating unit 77A generates the target voltage Vref set by the supply power control unit 92 and supplies it to the voltage error amplifier 71A.

[0071] The voltage error amplifier 71A calculates a differential voltage Vfb between the first input voltage V'(A) and the second input voltage Vref, and outputs it to the bidirectional switch 72A. For example, if the target voltage Vref is set to 2V, the output voltage of the converter 74A is set to 100V, and the voltage division ratio of the resistors 75A and 76A is set to 1 / 40, the first input voltage V'(A) becomes 2.5V, and the difference between 2V and 2.5V, 0.5V, is output as the differential voltage Vfb of an analog value.

[0072] The differential voltage Vfb, which is the output of the voltage error amplifier 71A, is supplied to the current-mode PWM controller 73A via the turned-on bidirectional switch 72A, and is also supplied to the current-mode PWM controller 73B of the power supply control circuit 52B of the slave display device 42B via connection line 93.

[0073] The current mode PWM controller 73A supplies a PWM signal generated based on the differential voltage Vfb from the voltage error amplifier 71A to the gate of the MOS-FET 82A of the converter 74A, thereby turning the MOS-FET 82A on and off.

[0074] When the value of the current flowing through the MOS-FET 82A is IRa and the MOS-FET 82A is turned on, the relationship between the differential voltage Vfb that is the output of the voltage error amplifier 71A and the value of the current IRa flowing through the MOS-FET 82A is as shown in FIG.

[0075] The current-mode PWM controller 73A turns on and off the MOS-FET 82A with a target value proportional to the differential voltage Vfb, which is the output of the voltage error amplifier 71A. As shown in Fig. 9, the current-mode PWM controller 73A controls the MOS-FET 82A to turn on and off so that when the differential voltage Vfb is large, the current value IRa flowing through the MOS-FET 82A, which is a switching element, becomes large, and when the differential voltage Vfb is small, the current value IRa flowing through the MOS-FET 82A, which is a switching element, becomes small. When the current value IRa flowing through the MOS-FET 82A increases and reaches the output of the voltage error amplifier 71A, the current-mode PWM controller 73A controls the MOS-FET 82A to turn off.

[0076] That is, the converter 74A controls the switching of the current flowing through the MOS-FET 82A to generate the first voltage V E _A to the second voltage V O This is a current mode controlled power supply circuit that converts the input current to _A and outputs it.

[0077] As described above, the power supply control circuit 52A controls the actual output voltage of the converter 74A (the second voltage V O The control circuit 71 controls a current value IRa flowing through a MOS-FET 82A based on an output from a voltage error amplifier 71A that outputs a differential voltage Vfb between a divided voltage value V'(A) of the input current V(_A) and a target voltage Vref.

[0078] The output of the voltage error amplifier 71A is also supplied to a current mode PWM controller 73B of a power supply control circuit 52B of the slave display device 42B via a connection line 93. Therefore, in the power supply control circuit 52B as well, a current value IRb flowing through a MOS-FET 82B is similarly controlled based on the output from the voltage error amplifier 71A.

[0079] In both power supply control circuits 52A and 52B, the current value IRa flowing through MOS-FET 82A and the current value IRb flowing through MOS-FET 82B are controlled based on the output from one voltage error amplifier 71A. In the power supply control circuits 52A and 52B, the inductances La and Lb of the inductors 81A and 81B are the same (La=Lb), and the resistances Ra and Rb of the resistors 83A and 83B are the same (Ra=Rb), so that the current values ​​IRa and IRb are the same. As a result, the power supply from the power supply 51A (second voltage V O _A) and power supply from power supply 51B (second voltage V O _B) is controlled to equilibrium.

[0080] According to the above first configuration example of the multi-display device 41, the power supply control circuits 52 (52A and 52B) of the multiple display devices 42 (42A and 42B) each obtain a control signal indicating whether to operate as a master or a slave. Then, the power supply control circuit 52A that obtains the master signal indicating that it operates as a master also controls the power supply control circuits 52B of the other display devices 42B.

[0081] The power supply control circuit 52A, which is the master, controls the output of its own power supply 51A and the output of the other power supply 51B so that the power supplies 51A and 51B of the two display devices 42A and 42B are balanced.

[0082] In the present embodiment, the case has been described where the screen sizes of display 53A and display 53B are the same, but for example, if the screen sizes of display 53A and display 53B are different, similar control can be performed by setting the ratio of inductances La and Lb and the ratio of resistance values ​​Ra and Rb to values ​​according to the ratio of power supplies 51 corresponding to the screen sizes. For example, by setting La=2Lb and Ra=2Rb, the output ratio of power supplies 51A and 51B can be set to 1:2.

[0083] <4. Second Configuration Example of Multi-Display Device> FIG. 10 shows a detailed second configuration example of the multi-display device 41 of FIG.

[0084] In FIG. 10, parts corresponding to those in the first configuration example shown in FIG. 8 are given the same reference numerals, and the description of those parts will be omitted as appropriate.

[0085] In the second configuration example, the two display devices 42A and 42B do not have a master-slave relationship as in the first configuration example, and the two display devices 42A and 42B have the same configuration. Therefore, the following will explain the display device 42A, and will provide supplementary information on the display device 42B as appropriate.

[0086] As in the first configuration example, the power supply control circuit 52A of the display device 42A has a voltage error amplifier 71A that compares a first input voltage V'(A) obtained by voltage division using resistors 75A and 76A with a second input voltage Vref generated by a target voltage generating unit 77A and outputs a differential voltage Vfb. The display device 42A has a supply power control unit 92A that calculates a target voltage Vref based on an image to be displayed on the display 53A and supplies the target voltage Vref to the target voltage generating unit 77A.

[0087] In addition, the power supply control circuit 52A controls the first voltage V E _A(Power supply voltage V E _A) to the second voltage V O The converter 101A converts the current into _A and outputs it. This converter 101A may be a current-mode controlled converter as in the first configuration example, or may be a converter using other control methods. That is, in the second configuration example, the converter control method does not matter.

[0088] Furthermore, the power supply control circuit 52A has a resistor 102A as a current detection element that detects the value of a current flowing through a display 53A as a load and converts it into a voltage, and an amplifier 103A that amplifies the converted voltage, in the output path of the converter 101A. Here, the resistance value of the resistor 102A is r aand the amplification factor of amplifier 103A is A a It is.

[0089] The power supply control circuit 52A also has a comparator 104A, the first input of which is input with a voltage Va that is the output of the amplifier 103A, and the second input of which is input with the opposite end point (the other end) of a resistor 105A, one end of which is connected to the output of the amplifier 103A.

[0090] Resistor 105A of the power supply control circuit 52A is connected to resistor 105B of the power supply control circuit 52B of the display device 42B via connection line 106, and the connection point between resistor 105A and resistor 105B is set as the second input of comparator 104A of the power supply control circuit 52A, so that the average value Vave of the output voltage Va of amplifier 103A of the power supply control circuit 52A and the output voltage Vb of amplifier 103B of the power supply control circuit 52B is input to the second input.

[0091] Comparator 104A compares the output voltage Va of amplifier 103A, which is a first input, with the average value Vave of the output voltages Va and Vb, which is a second input, and outputs the comparison result (voltage) to the connection point between target voltage generating unit 77A and resistor 106A.

[0092] The power supply control circuit 52A of the display device 42A is configured as described above, and the power supply control circuit 52B of the display device 42B is configured similarly to the power supply control circuit 52A. However, the resistance value of the resistor 102B in the power supply control circuit 52B is set to r b , the amplification factor of the amplifier 103B is A b Then, the resistance value r a =r b , amplification factor A a =A b It is.

[0093] The operation of the power supply control circuit 52A will now be described. In the comparator 104A, the output voltage Va of the amplifier 103A, which corresponds to the value of the current flowing through the output path of the converter 101A, is compared with the average value Vave, which corresponds to the average value of the current flowing through the output paths of the converters 101A and 101B. Then, based on the comparison result of the comparator 104A, the power supply (second voltage V O _B) is controlled. Specifically, when the current value of the converter 101A is smaller than the average current value, the comparator 104A outputs a comparison result (voltage) that increases the second input voltage Vref, which is the target voltage of the voltage error amplifier 71, and when the current value of the converter 101A is larger than the average current value, the comparator 104A outputs a comparison result (voltage) that decreases the second input voltage Vref, which is the target voltage of the voltage error amplifier 71.

[0094] Power supply control circuit 52B also performs a similar operation, thereby controlling power supply control circuits 52A and 52B so that the current values ​​output from converters 101A and 101B are equal to each other. That is, power supply control circuits 52A and 52B control the current values ​​so that the power supplies from power supplies 51A and 51B to two display devices 42A and 42B are balanced.

[0095] In addition, the resistance value r a =r b , amplification factor A a =A b This is the case when the screen sizes of the display 53A and the display 53B are the same. When the screen sizes of the display 53A and the display 53B are different, the resistance value r a andr b and the amplification factor A a and A b The ratio changes depending on the screen size (power supply).

[0096] In the above-mentioned embodiment, the power supply control circuit 52 is configured to control the power supply 51 mounted on each display device 42 of the multi-display device 41 that operates a plurality of display devices 42 in cooperation with each other, but the power supply control circuit 52 of the present technology can be applied to devices other than display devices. That is, the above-mentioned power supply control circuit 52 can be applied to a power supply control device that controls the power supply of each device when a plurality of devices cooperate to configure an entire device. For example, when the power supply control circuit 52 is used in a charger, charging can be accelerated when the number of connected batteries is small.

[0097] In the first configuration example of the power supply control circuit 52 shown in FIG. 8, the current flowing through the converter 74 is matched on a pulse-by-pulse basis, so that even in the case of a load with large fluctuations and large peaks, the peak load can be shared, and the power supply control circuit 52 is suitable for the multi-display device described above.

[0098] On the other hand, the second configuration example of power supply control circuit 52 in FIG. 10 has no restrictions on the type of converter 101, and can therefore be applied to devices such as chargers with small output fluctuations, thereby expanding the options for converter 101.

[0099] <5. Example of a composite device using this technology> FIG. 11 is a block diagram showing an example of the configuration of a multifunction peripheral when the power supply control of the present technology described above is applied to the multifunction peripheral with no limitations on its use.

[0100] The composite device 141 in FIG. 11 is made up of two devices 142A and 142B.

[0101] Since the device 142A and the device 142B have the same configuration, only the device 142A will be described and a description of the device 142B will be omitted.

[0102] The device 142A has a power supply 151A, a power supply control circuit 152A, and a load 153A. The power supply 151A supplies the load 153A with power V(A)×I(A) required for the load 153A to operate. The power supply control circuit 152A controls the power supply from the power supply 151A. More specifically, the power supply control circuit 152A controls the power supplied from the power supply 151A to the load 153A so that it becomes a target value. The load 153A receives the supply of power from the power supply 151A (consumes the power) and performs a predetermined operation.

[0103] The power supply control circuit 152A includes a calculation unit 171A, a Ref voltage generation unit 172A, a voltage detection unit 173A, a difference output unit 174A, and a control unit 175A.

[0104] The calculation unit 171A calculates a current value required for the load 153A and supplies it to the Ref voltage generation unit 172A. The Ref voltage generation unit 172A calculates a target voltage Vref(A) from the current value supplied from the calculation unit 171A and supplies it to the difference output unit 174A. The target voltage Vref(A) is a value obtained by taking into consideration a proportionality coefficient M similar to that of the voltage detection unit 173 to a voltage value corresponding to the required current value supplied from the calculation unit 171A.

[0105] In the example of multi-display device 41 described above, load 153A corresponds to display 53, and calculation unit 171A calculates the current value required for the video to be displayed on display 53.

[0106] The voltage detection unit 173A detects the actual output voltage V(A) from the power supply 151A to the load 153A, converts it to be proportional to the output voltage V(A), and supplies the converted voltage V'(A) to the difference output unit 174A. For example, the converted voltage V'(A) is a voltage such that V'(A)=V(A) / M (M>0).

[0107] The differential output unit 174A compares the target voltage Vref(A) supplied from the Ref voltage generating unit 172A with the converted voltage V'(A) supplied from the voltage detecting unit 173A, and based on the comparison result, generates a differential voltage Vfb(A) for feedback and supplies it to the control unit 175A.

[0108] The control unit 175A controls the power supply of the power supply 151A based on the differential voltage Vfb(A) from the differential output unit 174A. Specifically, when the converted voltage V'(A) is lower than the target voltage Vref(A), the control unit 175A controls to increase the voltage V(A) of the power supply 151A, and when the converted voltage V'(A) is higher than the target voltage Vref(A), the control unit 175A controls to decrease the voltage V(A) of the power supply 151A.

[0109] The device 142B has a similar configuration to the device 142A and performs a similar operation.

[0110] A voltage supply line 181A of the power supply 151A of the device 142A and a voltage supply line 181B of the power supply 151B of the device 142B are shared via a connection line 182. This makes the voltage V(A) of the power supply 151A and the voltage V(B) of the power supply 151B equal (V(A)=V(B)), and power is supplied to the load 153A and the load 153B from the two power supplies 151A and 151B.

[0111] For example, when the maximum power consumption of the load 153A of the device 142A alone is 100W (load 153A≦100W), the maximum power consumption of the load 153B of the device 142B alone is 100W (load 153B≦100W), and the maximum power consumption of the entire composite device 141 is 150W ({(load 153A)+(load 153B)}≦150W), the power supply 151 of each of the devices 142A and 142B only needs to have a supply capacity of 75W. In the conventional power supply control, each of the devices 142A and 142B needs to be provided with a power supply 151 with a supply capacity of 100W. Therefore, the power supply control of the present technology makes it possible to realize a smaller and less costly power supply 151.

[0112] Furthermore, as in the conventional method, if the power supplies 151 of the devices 142A and 142B are each provided with a supply capacity of 100 W, the overall supply capacity of the composite device 141 will be 200 W ({(load 153A)+(load 153B)}≦200 W). For example, it is possible to supply 200 W to load 153A and 0 W to load 153B.

[0113] FIG. 12 is a block diagram showing an example of the configuration of a multifunction peripheral 141 when the multifunction peripheral 141 is made up of four devices 142A to 142D.

[0114] Detailed description of each of the four devices 142A to 142D will be omitted since it is similar to Fig. 11, but a voltage supply line 181A of the power supply 151A of the device 142A, a voltage supply line 181B of the power supply 151B of the device 142B, a voltage supply line 181C of the power supply 151C of the device 142C, and a voltage supply line 181D of the power supply 151D of the device 142D are shared via a connection line 182. As a result, the loads 153A to 153D have the same magnitude, and voltages V(A) = V(B) = V(C) = V(D), so that the power supplied from each of the power supplies 151A to 151D is equal.

[0115] The embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present technology.

[0116] For example, it is possible to adopt a configuration in which all or part of the above-described embodiments are combined.

[0117] It should be noted that the effects described in this specification are merely examples and are not limiting, and there may be effects other than those described in this specification.

[0118] The present technology can have the following configurations. (1) A plurality of display devices each having a power supply having a predetermined supply power; a power supply connection section for connecting the power supplies of the plurality of display devices in parallel; Equipped with When at least one of the plurality of display devices requires power exceeding the predetermined supply power of a power supply of the display device, the display device is configured to receive power from a power supply of the other display device. Composite display device. (2) The display device is configured to be supplied with power from a power supply of another display device when the display device requires power exceeding the predetermined supply power of the power supply of the display device in a case where the display device performs display at a luminance higher than the luminance corresponding to the maximum value of the supply power of the display device. The composite display device according to (1) above. (3) The display device has a power supply control circuit that controls the power supply from the power supply itself, A first power supply control circuit, which is the power supply control circuit of a predetermined one of the plurality of display devices, also controls the power supply control circuits of the other display devices so that the power supplies of the power sources of the plurality of display devices are balanced. The composite display device according to (1) or (2). (4) the power supply control circuit of each of the plurality of display devices receives a control signal for controlling whether or not the power supply control circuit operates as the first power supply control circuit that also controls the power supply control circuits of the other display devices; A predetermined one of the power supply control circuits that has acquired a control signal indicating that it operates as the first power supply control circuit operates as the first power supply control circuit. The composite display device according to (3) above. (5) The power supply control circuit controls the power supply from the power supply based on an output from a difference output unit that outputs a difference between an actual output voltage from the power supply and a target voltage. A composite display device according to (3) or (4). (6) The power supply control circuit includes a power supply circuit that is current-mode controlled, and controls the power supply from the power supply by switching control of a current. A composite display device according to any one of (3) to (5). (7) The control signal generating unit generates and outputs the control signal. The composite display device according to (4) above. (8) The power supply control unit sets the target voltage. The composite display device according to (5) above. (9) The display device has a power supply control circuit that controls the power supply from the power supply itself, The power supply control circuit controls the power supplies of the display devices so that the power supplies of the display devices are balanced. A composite display device according to (1) or (2). (10) The power supply control circuit has a current detection element that detects a current value flowing through a load of its own display device and converts the current value into a voltage, compares a first voltage converted by the current detection element with a second voltage corresponding to an average value of the current value flowing through the load of each of the plurality of display devices, and controls the power supply of the power supply based on the comparison result. The composite display device according to (9) above. (11) A plurality of display devices each having a power supply having a predetermined supply power; a power supply connection section for connecting the power supplies of the plurality of display devices in parallel; A method for controlling a composite display device comprising: When a first display device of the plurality of display devices requires power exceeding a predetermined supply power of a power source of the first display device, a second display device of the plurality of display devices supplies power to the first display device. A method for controlling a composite display device. [Explanation of symbols]

[0119] 41 multi-display device, 42A,42B display device, 51A,51B power supply, 52A,52B power supply control circuit, 53A,53B display, 54A,54B power supply line, 55 power supply connection line, 71A,71B voltage error amplifier, 72A,72B bidirectional switch, 73A,73B current mode PWM controller, 74A,74B converter, 75A,75B,76A,76B resistor, 77A,77B target voltage generation unit, 81A,81B inductor, 82A,82B MOS-FET, 83A,83B resistor, 84A,84B diode, 85A,85B capacitor, 91 master / slave signal generation unit, 92 power supply control unit, 93 connection line, 101A,101B Converter, 102A, 102B Resistor, 103A, 103B Amplifier, 104A, 104B Comparator, 105A, 105B Resistor, 141 Composite device, 142A to 142D Device, 151A to 151D Power supply, 152A to 152D Power supply control circuit, 153A to 153D Load, 171A to 171D Calculation unit, 172A to 172D Ref voltage generation unit, 173A to 173D Voltage detection unit, 174A to 174D Differential output unit, 175A to 175D Control unit, 181A to 181D Voltage supply line

Claims

1. A plurality of display devices each having a power supply having a predetermined supply power; a power supply connection section for connecting the power supplies of the plurality of display devices in parallel; Equipped with at least one of the plurality of display devices is configured to receive power from a power supply of the other display device when the at least one display device requires power that exceeds the predetermined supply power of the power supply of the at least one display device; The display device has a power supply control circuit that controls the power supply from the power supply itself, a first power supply control circuit which is the power supply control circuit of a predetermined one of the plurality of display devices controls the power supply control circuits of the other display devices so that the power supplies of the power sources of the plurality of display devices are balanced; The first power supply control circuit controls the power supply from the power supply based on an output from a difference output section that outputs a difference between an actual output voltage from the power supply and a target voltage. Composite display device.

2. The display device is configured to be supplied with power from a power supply of another display device when the display device requires power exceeding the predetermined supply power of the power supply of the display device in a case where the display device performs display at a luminance higher than the luminance corresponding to the maximum value of the supply power of the display device.

2. The composite display device of claim 1.

3. the power supply control circuit of each of the plurality of display devices receives a control signal for controlling whether or not the power supply control circuit operates as the first power supply control circuit that also controls the power supply control circuits of the other display devices; A predetermined one of the power supply control circuits that has acquired a control signal indicating that it operates as the first power supply control circuit operates as the first power supply control circuit.

2. The composite display device of claim 1.

4. The power supply control circuit includes a power supply circuit that is current-mode controlled, and controls the power supply from the power supply by switching control of a current.

2. The composite display device of claim 1.

5. The control signal generating unit generates and outputs the control signal.

4. The composite display device according to claim 3.

6. The power supply control unit sets the target voltage.

2. The composite display device of claim 1.

7. A plurality of display devices, each of which has a power supply having a predetermined supply power; a power supply connection section for connecting the power supplies of the plurality of display devices in parallel; Equipped with at least one of the plurality of display devices is configured to receive power from a power supply of the other display device when the at least one display device requires power that exceeds the predetermined supply power of the power supply of the at least one display device; The display device has a power supply control circuit that controls the power supply from the power supply itself, the power supply control circuit controls the power supplies of the respective display devices so as to balance the power supplies of the respective display devices; The power supply control circuit has a current detection element that detects a current value flowing through a load of its own display device and converts the current value into a voltage, compares a first voltage converted by the current detection element with a second voltage corresponding to an average value of the current value flowing through the load of each of the plurality of display devices, and controls the power supply of the power supply based on the comparison result. Composite display device.

8. A plurality of display devices each having a power supply having a predetermined supply power; a power supply connection section for connecting the power supplies of the plurality of display devices in parallel; A method for controlling a composite display device comprising: The display device has a power supply control circuit that controls the power supply from the power supply itself, when a first display device of the plurality of display devices requires power exceeding a predetermined supply power of a power source of the first display device, a second display device of the plurality of display devices supplies power to the first display device; a first power supply control circuit which is the power supply control circuit of a predetermined one of the plurality of display devices controls the power supply control circuits of the other display devices so that the power supplies of the power sources of the plurality of display devices are balanced; The first power supply control circuit controls the power supply from the power supply based on an output from a difference output section that outputs a difference between an actual output voltage from the power supply and a target voltage. A method for controlling a composite display device.

9. A plurality of display devices, each of which is provided with a power supply having a predetermined supply power; a power supply connection section for connecting the power supplies of the plurality of display devices in parallel; A method for controlling a composite display device comprising: The display device has a power supply control circuit that controls the power supply from the power supply itself, when a first display device of the plurality of display devices requires power exceeding a predetermined supply power of a power source of the first display device, a second display device of the plurality of display devices supplies power to the first display device; the power supply control circuit controls the power supplies of the respective display devices so as to balance the power supplies of the respective display devices; The power supply control circuit has a current detection element that detects a current value flowing through a load of its own display device and converts the current value into a voltage, compares a first voltage converted by the current detection element with a second voltage corresponding to an average value of the current value flowing through the load of each of the plurality of display devices, and controls the power supply of the power supply based on the comparison result. A method for controlling a composite display device.

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