JP2018029028A - Display device, control method thereof and control program thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that can supply power to external equipment while suppressing an increase in the capacity of an internal power supply.SOLUTION: A display device 10 comprises: a display panel 11 that displays an image; a backlight 12 that emits light from a back face of the display panel 11; an external connection interface 13 that connects external equipment 20; an internal power supply 14 that supplies power to the backlight 12 and the connected external equipment 20; and a control unit 15 that controls brightness of the backlight 12 on the basis of requested power required to be supplied to the external equipment 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device, a control method thereof, and a control program thereof, and more particularly to a display device to which an external device is connected, a control method thereof, and a control program thereof.

  In order to supply power to an external device such as a peripheral device as an accessory power source, a display device (video display device, image display device) having an optional power supply terminal such as a USB is known. For example, Patent Documents 1 to 6 are known as related techniques.

  In recent years, functions and necessary power of USB devices have been diversified, and there has been a demand for supplying large power from a display device having a USB terminal to an external device. The USB Type C standard and the USB 3.1 power delivery standard, which are new USB standards, fulfill such a demand.

JP-A-10-116139 JP 2001-094662 A JP-T-2005-524101 JP 2008-085935 A JP 2010-002503 A JP 2009-153336 A

  However, even if a new standard such as USB Type C is used, in the related display device, it is necessary to increase the capacity of the power supply of the display device in order to supply large power to the external device. Then, the volume of the power supply circuit (power supply device) increases as the capacity of the power supply increases. Furthermore, an increase in the volume of the power supply circuit is directly connected to an increase in the volume of the display device itself. Increasing the size of the display device is not desirable for the user.

  For example, the power consumption of a general information processing display device is about 40 [W]. To supply 30 [W] power (an example of USB Type C) to an external device, a total of 70 [W] is required. A power supply was needed. In this case, the power supply is nearly twice as large as the power capacity (40 [W]) of the initial design that does not assume an external device.

  Therefore, in the related technology, there is a problem that it is difficult to supply power from the display device to the external device while suppressing an increase in the internal power supply.

  In view of such problems, it is an object of the present invention to provide a display device capable of supplying power to an external device while suppressing an increase in internal power supply, a control method thereof, and a control program thereof.

  A display device according to the present invention includes a display panel that displays an image, a backlight that emits light from the back of the display panel, an external connection interface that connects an external device, the backlight, and the connected external device. An internal power supply that supplies power to the external device, and a control unit that controls the brightness of the backlight based on the required power that needs to be supplied to the external device.

  A display device control method according to the present invention is a display device control method including a display panel that displays an image and a backlight that emits light from the back surface of the display panel. A device is connected, power is supplied from an internal power source to the backlight and the connected external device, and brightness of the backlight is controlled based on required power that needs to be supplied to the external device. .

  A control program for a display device according to the present invention is a control program for causing a display device provided with a display panel for displaying an image and a backlight for irradiating light from the back of the display panel, Connect an external device to the connection interface, supply power from the internal power supply to the backlight and the connected external device, and control the brightness of the backlight based on the required power that needs to be supplied to the external device To do.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which can supply electric power to an external apparatus, the control method, and its control program can be provided, suppressing the increase in internal power supply.

It is a block diagram which shows the example of a schematic structure of the display apparatus which concerns on embodiment. 3 is a block diagram illustrating a configuration example of a display device according to Embodiment 1. FIG. 4 is a flowchart illustrating an operation example of the display device according to the first embodiment. 6 is a graph showing a relationship between brightness setting and backlight output for explaining an operation example of the display device according to the first embodiment. 10 is a block diagram illustrating a configuration example of a display device according to Embodiment 2. FIG.

(Outline of the embodiment)
First, the outline of the embodiment will be described with reference to FIG. As shown in FIG. 1, the display device 10 according to the embodiment includes a display panel 11, a backlight 12, an external connection interface 13, an internal power supply 14, and a control unit 15.

  The display panel 11 is a display unit that displays an image, such as a liquid crystal panel. The backlight 12 is an irradiation unit that emits light from the back surface of the display panel 11. The external connection interface 13 is an interface for connecting an external device 20 such as a USB. The internal power supply 14 is a power supply unit that supplies power to the external device 20 connected to the backlight 12 and the external connection interface 13. The control unit 15 controls the brightness of the backlight 12 based on the required power that needs to be supplied to the external device 20.

  With such a configuration, when a high-power external device is connected to an external connection interface such as a USB, the embodiment gives priority to supplying power to the external device, and in order to cover the power of the display device, There is a feature that power is accommodated by limiting the brightness of the backlight.

  For example, in the related technology, the size of the power supply that can supply 70 [W] is required to cover the power 40 [W] in the display device and the power 30 [W] of the external device. Is used, the power of the backlight is limited to allow a margin of power, so that the required power of the external device can be supplied with a power size of 40 [W].

  Without increasing the size of the display device due to increased power supply, which was a problem with the related technology, without changing the size of the display device, when necessary, on the port (interface) side such as USB, A feature of the embodiment is that a large amount of power exceeding 6 times (5 [W]-> 30 [W]), for example, can be distributed in comparison with the related art.

  That is, in the embodiment, since the volume of the power source is not changed, the size of the display device is not changed. Furthermore, in the embodiment, it is possible to connect a high-power device, and there is an effect that the range of devices that can be connected to the display device is widened.

  For example, by connecting a notebook personal computer (laptop personal computer) that could not be driven by the related USB to the USB terminal of the display device, the notebook personal computer can be driven without an AC adapter. At this time, since the power supply and the signal can be communicated with the same cable, the number of cables around the display device can be reduced, and the installation environment of the display device can be improved.

  Furthermore, in the related method, there is an example in which the brightness of the backlight is adjusted by the number of lighted LEDs, but in this case, unevenness in brightness occurs by reducing the number of lighted LEDs. However, in the embodiment, it is possible to keep the screen brightness uniform by controlling the brightness on the entire screen.

  In addition, there is an example in which the related method is applied to a device using a battery, but in this case, it is for the purpose of suppressing the degree of battery decrease, and it is not assumed that the external device is a high-power device. It was. However, in the embodiment, it is assumed that a high-power device is connected, and power is preferentially distributed to the USB external device.

(Embodiment 1)
The first embodiment will be described below with reference to the drawings. FIG. 2 shows a configuration example of a display device (image display device) 100 according to the present embodiment. For example, the display device 100 is a liquid crystal display device that displays an image on a liquid crystal panel. FIG. 2 shows a state in which an external device 200 such as a mouse or a notebook PC is connected to a USB terminal (USB port).

  The display device 100 includes a power control unit 110, which is a main part of the present embodiment, and other devices necessary for the image display device. Specifically, as illustrated in FIG. 2, the display device 100 includes a power supply unit 101, a USB port 102, a USB control unit 103, a backlight 104, a backlight control unit 105, a power detection unit 111, and a power detection unit 112. A distributed power calculation unit 113, a brightness control unit 114, and a brightness setting unit 115.

  The power supply unit 101 is an internal power supply of the display device 100, supplies power to each internal component including the backlight 104 (backlight control unit 105), and further supplies power to the external device 200 via the USB port 102. Supply. The USB port 102 is a port (interface) for connecting the external device 200 which is a USB device, and is a port for transmitting and receiving signals and supplying power according to the USB standard. The USB control unit 103 acquires connection control with the external device 200 connected to the USB port 102 and a requested current requested by the external device 200.

  The backlight 104 is a backlight for a liquid crystal panel (not shown), and includes a backlight light source such as an LED. The backlight control unit (backlight drive unit) 105 drives the backlight 104 based on the power supplied from the power supply unit 101. The backlight control unit 105 includes, for example, a DC-DC converter, and generates driving power for the backlight 104 in accordance with a power control value (brightness control value) from the brightness control unit 114. For example, the backlight control unit 105 generates a PWM (Pulse Width Modulation) signal (periodic pulse signal), and drives the backlight 104 with the generated PWM signal. Therefore, the power control value is a PWM duty (duty ratio). .

  For example, the power detection unit 111, the power detection unit 112, the distributed power calculation unit 113, and the brightness control unit 114 are power control units that control the power (brightness) of the backlight 104 based on the required power of the external device 200. 110 is configured. The power detection unit (first power detection unit) 111 is an external device power detection unit that detects required power requested by the external device 200. For example, the power detection unit 111 acquires the required current of the external device 200 from the USB control unit 103, and calculates the required power of the external device 200 based on the acquired request current. The required power may be the power requested from the external device 200, or may be the power detected by the detector (current detector or power detector) that is supplied to the external device 200. The power detection unit (second power detection unit) 112 is a backlight power detection unit that detects the power (power consumption, drive power) of the backlight 104. For example, the power detection unit 112 acquires the current (consumption current, drive current) of the backlight 104 from the backlight control unit 105, and calculates the power of the backlight 104 based on the acquired current.

  The distributed power calculation unit 113 obtains power to be distributed to the external device 200 and the backlight 104 based on the power supply power information of the power supplied from the power supply unit 101. The distributed power calculation unit 113 determines the power of the external device 200 and the backlight 104 based on the required power of the external device 200 detected by the power detection unit 111 and the power of the backlight 104 detected by the power detection unit 112. To do.

  The brightness setting unit 115 is a setting unit for the user to set the brightness (luminance) of the display screen (backlight). The brightness setting unit 115 includes a memory (storage unit), and stores the brightness setting value set in the memory. The brightness control unit 114 determines the power (brightness) of the backlight 104 based on the power of the backlight 104 (power based on the required power) obtained by the distributed power calculation unit 113 and the brightness setting value of the brightness setting unit 115. A power control value for controlling

  In the present embodiment, as an example, the display device 100 is a device on which a 40 [W] power source (power supply unit 101) is mounted, and the external device (USB device) 200 has a maximum power of 30 [W]. The display device internal device including the backlight 104 requires a maximum of 30 [W] power (maximum internal power). The power supply margin power is 10 [W] obtained by subtracting the maximum internal power 30 [W] from the maximum (total) power 40 [W] that can be supplied by the power supply.

  Next, the operation of the display device 100 including the power control unit 110 according to the present embodiment will be described using the flowchart of FIG.

  As shown in FIG. 3, first, as a control operation on the USB side, the USB control unit 103 connects the USB power line using the information communication with the external device 200 from the USB port 102 or a current detector (not shown). By detecting the value of the flowing current, the current of the external device 200 is captured (S101). The USB control unit 103 acquires current information required by the external device 200 by transmitting and receiving signals according to a communication protocol (USB standard) with the external device 200. When the current detector is used, the current value flowing through the power line of the USB cable is acquired by the current sensor.

  At this time, the required current value is sent from the USB control unit 103 to the power detection unit 111 in the next stage, and the power detection unit 111 calculates the required power (demand power) from the product of the supply voltage from the power source and the required current of the external device 200. To detect. When the voltage supplied to the external device 200 is fixed, the required power may be obtained using a predetermined voltage and the required current (or detection current), and when the supplied voltage is variable, the external device The required power may be obtained using the required voltage (or detected voltage) acquired from 200.

  Subsequently, the distributed power calculation unit 113 determines the required power of the external device 200 (S102, S104), and determines the subsequent control operation of the backlight 104 as follows.

1. When the required power from the external device 200 is 10 [W] or less, the distributed power calculation unit 113 is when the required power from the external device 200 is 10 [W] or less (less than the supply surplus power) (Yes in S102). It is determined that the required power is supplied as it is. That is, since the total power of the required power of the external device 200 and the power inside the apparatus is equal to or less than the power supply capacity (40 [W]), the brightness limitation (power limitation) of the backlight 104 is not performed (S103). In this case, the USB control unit 103 performs control so that required power is supplied from the USB port 102 to the external device 200.

2. When the required power from the external device 200 is 30 [W] or more, the distributed power calculation unit 113, when the required power from the external device 200 is 30 [W] or more (greater than the maximum internal power) (Yes in S104), Since the supply capacity from the power source is exceeded, it is determined that the maximum power (30 [W]) that can be supplied is supplied (S105). The brightness of the backlight 104 is limited so that the total power of the external required power and the internal power is less than the power supply capacity (40 [W]). That is, the display device internal device including the backlight 104 is controlled to use a maximum of 10 [W] power (supply margin power) and the external device 200 can use 30 [W] power. In this case, the USB control unit 103 performs control to supply 30 [W] power from the USB port 102 to the external device 200.

3. When the required power from the external device 200 is 10 [W] or more and 30 [W] or less, the distributed power calculation unit 113 has a required power from the external device 200 of 10 [W] or more and 30 [W] or less (supply margin) If it is within the range from the power to the maximum internal power (No in S104), it is determined that the requested power (maximum 30 [W]) is supplied based on the required power information from the external device 200 (S106). That is, the display device internal device including the backlight 104 is controlled to use the differential power obtained by subtracting the required power from 40 [W] at the maximum. In this case, the USB control unit 103 performs control so that required power is supplied from the USB port 102 to the external device 200.

  On the other hand, as a control operation on the backlight side, as with the USB side, the backlight control unit 105 detects the value of the current flowing through the backlight 104 using, for example, a current detector (not shown), so that the backlight 104 Current is taken in (S111). Further, the current value is sent from the backlight control unit 105 to the power detection unit 112 in the next stage, and the power detection unit 112 determines the current supply power of the backlight 104 based on the product of the power supplied to the backlight 104 and the detected current. (Power consumption) is calculated (S112).

  Subsequently, the distributed power calculation unit 113 calculates power distribution based on the power to the external device 200 determined in S105 or S106 and the power of the backlight 104 determined in S112 (S113). The distributed power calculation unit 113 includes power supply power information (information on the total power that can be supplied by the power supply), information on the required power sent from the USB power detection unit 111, and consumption received from the power detection unit 112 of the backlight 104. The power value that can be supplied to the backlight 104 is calculated from the power information. Specifically, information on the power that can be supplied from the power supply is received, the difference between the power values required by the external device 200 is obtained from the value, and the difference power is set as the power that can be used by the backlight 104 (internal device). The power should be used preferentially by the backlight).

  Subsequently, the brightness control unit 114 generates brightness limit information (power control value) for the backlight 104 so that the power is equal to or lower than the specified value, and outputs the brightness limit information to the backlight control unit 105 (S114). FIG. 4 shows the relationship between the brightness setting set by the user in the brightness setting unit 115 (in the storage unit) and the backlight output (power). That is, as shown in FIG. 4, the brightness setting set by the user is limited by the required power of the external device 200. The brightness of the backlight 104 is corrected until the required power of the external device 200 is met by correcting the power limit information (power determined to be usable by the backlight 104) sent from the previous stage based on the brightness set by the user. Limit. The brightness setting value (power control value) at that time is output to the backlight control unit 105.

  As described above, in the present embodiment, the brightness setting of the backlight is limited based on the required power of the external device, and the power of the backlight is suppressed. Can be distributed to devices.

  For example, it is assumed that the display device is equipped with a power supply of 40 [W], the required power of the USB external device is 10 [W], and the power of the backlight is 30 [W]. Here, even if the required power of the external device increases to 30 [W], the display device of this embodiment limits the brightness of the backlight and suppresses the backlight power to 10 [W]. The necessary power can be supplied to the external device without increasing the power supply power. As a result, although the related technology required that a power supply of 70 [W] be mounted on the display device, by using this embodiment, the power supply capacity can be increased to supply power to external devices. There is no need to increase the power, and power can be supplied to the external device with the power supply of 40 [W].

  When a plurality of external devices are connected, if the required power can be supplied to all the external devices, the brightness of the backlight is limited and supplied. On the other hand, if power cannot be supplied to all external devices, a mode in which power is supplied only to power saving devices and a mode in which a specific device is selected and supplied may be switched. In this case, an external device connected to each USB port is detected by the USB control unit 103 in FIG. 2, and is classified into an external device with low power consumption and an external device with high power consumption. For example, according to the flowchart of FIG. 3, a device with a small power consumption and a device with a large power consumption are classified according to whether the power consumption per device is 10 [W] or less.

  When a mode in which a large number of devices with low power consumption are connected is selected, power is not supplied to a device with high power consumption and the device cannot be used, but a plurality of devices with low power consumption can be connected. Many USB devices are portable, and many devices operate with low power consumption. Therefore, in this mode, the operation of the high-power device is sacrificed, but a large number of devices can be connected, so that USB external devices can be used in parallel.

  On the other hand, a high-power device can be used in a mode in which power is supplied by selecting a specific device. In this mode, a list of USB external devices detected by the USB control unit is presented (displayed), and a device that the user wants to use is selected from the list to supply power. In this mode, instead of being able to select a high-power device, a small number of devices can not be connected. Although it can be subdivided into a mode in which multiple devices can be selected within the power range that can be supplied from the power supply and a mode in which devices to be operated alternatively can be selected, the former is included in a mode in which many devices with low power consumption are connected. Therefore, in this embodiment, the latter operation is performed in a mode in which a specific device is selected and power is supplied.

(Embodiment 2)
Next, Embodiment 2 will be described with reference to the drawings. In the first embodiment, the example in which the USB device is connected to the display device has been described. However, the embodiment may be applied to devices other than the USB device. For example, in the present embodiment, an example in which an external device is connected to a display port (DP) of a display device will be described.

  For example, 3.3 [V] power is supplied to the Display Port (DP), and when an external device is connected in a daisy chain, the Display Port OUT is required. By connecting an external device operating at 3.3 [V] to this OUT terminal, the operation of the external device becomes possible.

  The current that can be applied to the current DisplayPort is limited by the DisplayPort control unit and the DisplayPort cable, but if the restriction is relaxed, only the power supplied from the display device to external devices connected in a daisy chain by the daisy chain function can be used. It becomes possible to operate with.

  At that time, by using the same algorithm as in the first embodiment, the brightness of the backlight is limited, so that a large amount of power can be supplied to an external device connected to the DisplayPort. Further, since the external devices can be connected to each other without taking out a number of cables from the display device like USB, space can be saved.

  FIG. 5 shows a configuration example of the display device 100 according to the present embodiment. As shown in FIG. 5, the display device 100 according to the present embodiment includes a DP port 121 and a DP control unit 122 instead of the USB port 102 and the USB control unit 103 as compared with the first embodiment of FIG. 2. The other configurations are the same as those of the first embodiment.

  The DP port 121 is a port (interface) for connecting the DisplayPort compatible external device 200, and is a port for transmitting and receiving signals and supplying power according to the DisplayPort standard. The DP control unit 122 acquires connection control with the external device 200 connected to the DP port 121 and a requested current requested by the external device 200.

  The rough power flow and signal flow of the display device 100 according to the present embodiment are the same as those in the first embodiment. However, when the external device is daisy chained, the power information of the lower device is obtained from the upper device. It is necessary to provide feedback through the device. Based on the information, the DP control unit 122 determines power distribution between the external device 200a and the external device 200b. Therefore, the operation changes depending on whether power can be supplied to all external devices 200.

1. When power can be supplied to all external devices 200 When power can be supplied to all the external devices 200 by dimming the backlight 104, the backlight 104 is dimmed to cover the necessary power to the external devices 200. All the external devices 200 are operated.

2. When power cannot be supplied to all external devices 200 When power cannot be supplied to all external devices 200 even if the backlight 104 is dimmed, a device that can be used is selected as in the first embodiment of the USB. . For example, when operating only the external device 200a, the display port control unit supplies power only to the external device 200a and does not supply power to the external device 200b.

In this manner, even when DisplayPort is used, high power can be supplied to an external device by using this embodiment. Since DisplayPort can handle not only video signals but also data signals, it is an interface with low hurdles for external device connection, and therefore the invention can be implemented without changing USB external device connection and a large algorithm.
(Other embodiments)

  In the above embodiment, the backlight is dimmed (brightness control) in accordance with the power supplied to the external device, so that the user may feel the darkness of the screen. In order to reduce this, for example, the following measures may be applied to the above embodiment.

1. Brightness is improved by loosening unevenness correction.
In the above embodiment, when the backlight control unit performs the unevenness correction of the backlight, the brightness of the center portion of the screen is darkened by performing the unevenness correction, so the correction amount of the unevenness correction is reduced. Therefore, the decrease in brightness can be alleviated.

2. The user is notified of a decrease in brightness by displaying a warning screen before dark.
Since it is an unpleasant phenomenon for the user that the screen becomes dark when an external device is connected, when the backlight control unit lowers the brightness of the backlight in the above embodiment, the screen of the display device (display The brightness of the screen will be limited. Notification to the user is not limited to display, but may be performed by sound, vibration, or other means.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

  Each structure in the said embodiment is comprised by hardware or software, or both, and may be comprised from one hardware or software, and may be comprised from several hardware or software. Each function (each process) in the embodiment may be realized by a computer having a CPU, a memory, and the like. For example, a display program (control program) for performing the display method (control method) in the embodiment is stored in a storage device (storage medium), and each function is executed by the CPU with the display program stored in the storage device. May be realized.

  Such a program can be stored using various types of non-transitory computer readable media and supplied to a computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W and semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)) are included. The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

DESCRIPTION OF SYMBOLS 10 Display apparatus 11 Display panel 12 Backlight 13 External connection interface 14 Internal power supply 15 Control part 20 External apparatus 100 Display apparatus 101 Power supply part 102 USB port 103 USB control part 104 Backlight 105 Backlight control part 110 Power control part 111 Electric power Detection unit 112 Power detection unit 113 Distributed power calculation unit 114 Brightness control unit 115 Brightness setting unit 121 DP port 122 DP control unit 200, 200a, 200b External device

Claims (10)

A display panel for displaying images,
A backlight that emits light from the back of the display panel;
An external connection interface for connecting external devices;
An internal power supply for supplying power to the backlight and the connected external device;
A control unit that controls brightness of the backlight based on required power that needs to be supplied to the external device. The required power is a power detected from the external device or a detection value obtained by detecting a power supplied to the external device by a detector.
The display device according to claim 1. The internal power supply can supply the total power of the maximum internal power and supply surplus power required inside the display device including the backlight,
The control unit does not limit the brightness of the backlight when the required power is smaller than the supply margin power,
The display device according to claim 1. The control unit supplies the maximum internal power to the external device when the required power exceeds the maximum internal power, and brightness of the backlight so that the power of the backlight is lower than the supply surplus power. Limit,
The display device according to claim 3. The control unit supplies the required power to the external device when the required power is within the range of the supply surplus power and the maximum internal power, and the power of the backlight is the total power of the internal power supply. Limiting the brightness of the backlight to be lower than the difference power from the required power;
The display device according to claim 3 or 4. A brightness setting unit for setting the brightness of the backlight;
The control unit controls the brightness of the backlight based on the set brightness and the required power.
The display device according to any one of claims 1 to 5. A backlight driving unit for driving the backlight by a PWM signal;
The control unit controls the brightness of the backlight by controlling the duty of the PWM signal.
The display apparatus as described in any one of Claims 1 thru | or 6. The external connection interface is an interface compliant with the USB standard or the DisplayPort standard.
The display device according to claim 1. A control method for a display device comprising: a display panel that displays an image; and a backlight that emits light from the back surface of the display panel,
Connect an external device to the external connection interface,
Supply power from an internal power source to the backlight and the connected external device,
Controlling the brightness of the backlight based on the required power that needs to be supplied to the external device;
Display device control method. A control program for causing a display device including a display panel to display an image and a backlight to emit light from the back of the display panel to execute the program,
Connect an external device to the external connection interface,
Supply power from an internal power source to the backlight and the connected external device,
Controlling the brightness of the backlight based on the required power that needs to be supplied to the external device;
Display device control program.

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