Display device, display system, and display control method

Abstract

The present invention provides a display device, a display system, and a display control method. In a display device supplied with power through a wiring harness, a technology is provided that can appropriately suppress a current exceeding an allowable current flowing through the wiring harness. The display device mounted on a vehicle and supplied with power through a wiring harness comprises a display, a speaker, and a control unit. The control unit performs a current suppression process that limits the sum of currents supplied to the display and the speaker based on at least one of information on an image displayed on the display and information on sound output from the speaker.

Description

Technical Field

[0001] The invention relates to a display device, a display system and a display control method. Background Art

[0002] In the past, a display device is known that changes the driving current supplied to the light-emitting element of the display device to a low current when the voltage supplied from the battery becomes below a threshold value (for example, see Patent Document 1). In addition, a technology is known that reduces the brightness of the organic EL display and switches to a power saving mode when the battery voltage decreases in a portable terminal such as a smartphone or tablet computer.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-172723

[0006] However, in a display device equipped with a speaker, in addition to the display, the speaker also consumes current. Therefore, even if the device is switched to the power saving mode described above, if the output of the speaker is large, the current consumption may not be sufficiently reduced. In particular, in a display device that is powered by a wiring harness, although it is intended that a current exceeding the allowable current does not flow through the wiring harness, there is a possibility that even in the power saving mode, the output of the speaker is large, thereby causing a current exceeding the allowable current to flow through the wiring harness. In addition, if the device is configured to frequently switch to the power saving mode, the brightness of the image will frequently decrease, and the user may find it difficult to see the image clearly. Summary of the invention

[0007] The present invention is proposed in view of the above-mentioned problems, and its purpose is to provide a technology that can appropriately suppress a current exceeding the allowable current from flowing through the wiring harness in a display device that is powered by a wiring harness. In addition, another purpose of the present invention is to provide a technology that can suppress a current exceeding the allowable current from flowing through the wiring harness and suppress the image from being difficult to see in a display device that is powered by a wiring harness.

[0008] In order to achieve the above-mentioned purpose, the display device of the present invention has the following structure (the first structure): the display device is mounted on a vehicle and is powered by a wiring harness, and the display device comprises: a display; a speaker; and a control unit that performs current suppression processing to limit the sum of currents supplied to the display and the speaker based on at least one of information on an image displayed on the display and information on a sound output from the speaker.

[0009] In addition, based on the display device of the above-mentioned first structure, it can be the following structure (second structure): the sound information includes the set volume of the speaker, the control unit uses the set volume being above a given volume threshold as one of the conditions to perform the current suppression process, and the current suppression process includes a process of reducing the current provided to the display.

[0010] In addition, based on the display device of the above-mentioned first structure, it can be the following structure (third structure): the sound information includes the output volume from the speaker, the control unit uses the output volume being above a given volume threshold as one of the conditions to perform the current suppression processing, and the current suppression processing includes processing to reduce the current provided to the display.

[0011] In addition, based on the display device of the above-mentioned first structure, it can be the following structure (fourth structure): the brightness of the display is included in the information of the image, the control unit uses the brightness being above a given brightness threshold as one of the conditions to perform the current suppression process, and the current suppression process includes a process of reducing the current provided to the speaker.

[0012] In addition, based on the display device of the above-mentioned first structure, it can be the following structure (the fifth structure): it also includes: a buffer for temporarily storing the information of the image; and a calculation unit for obtaining a calculation value related to the consumption current of the display based on the pixel value information contained in the information of the image stored in the buffer, and the sound information includes the set volume of the speaker. The control unit will perform the current suppression processing based on one of the conditions that the consumption current of the display is estimated to be above a given current threshold value and the set volume is above a given volume threshold value based on the calculation value.

[0013] In addition, based on the display device of the above-mentioned first structure, it can be the following structure (sixth structure): the control unit uses the sum of the estimated current consumption of the display obtained based on the information of the image and the estimated current consumption of the speaker obtained based on the information of the sound to be above a given current consumption threshold as one of the conditions to perform the current suppression processing.

[0014] In addition, based on any one of the above-mentioned structures 1 to 6, the display device may be configured as follows (structure 7): the control unit performs the current suppression processing under the further condition that the voltage of the battery serving as the power supply source becomes below a given voltage threshold.

[0015] In addition, in the display device according to any one of the first to seventh structures, the following structure (eighth structure) may be adopted: the current suppression process includes a process of reducing the set volume of the speaker.

[0016] In addition, the display device according to any one of the first to eighth structures may be configured as follows (ninth structure): the current suppression process includes a process of reducing the brightness of an image displayed on the display.

[0017] In addition, the display device according to any one of the first to ninth structures may be configured as follows (a tenth structure): the current suppression process includes a process of changing the color tone of an image displayed on the display.

[0018] In addition, based on any one of the above-mentioned structures 1 to 10, the display device can be configured as follows (structure 11): the speaker is a display speaker that vibrates a display panel of the display to output sound.

[0019] In addition, the display device according to any one of the first to eleventh structures may be configured as follows (twelfth structure): the display device is connected to a main component mounted on the vehicle via the wiring harness.

[0020] In addition, in order to achieve the above-mentioned purpose, the display system of the present invention has the following structure (Structure 13): it comprises: a main component mounted on a vehicle; and a display device connected to the main component through a wiring harness and supplied with power through the wiring harness, the main component comprising: a control unit that performs current suppression processing to limit the sum of currents supplied to the display and the speaker based on at least one of information on an image displayed on the display of the display device and information on a sound output from a speaker of the display device.

[0021] In addition, in order to achieve the above-mentioned purpose, the display control method of the present invention becomes the following structure (14th structure): it is a display control method for a display device mounted on a vehicle and supplied with power through a wiring harness, and a current suppression process is performed to limit the sum of the currents provided to the display and the speaker based on at least one of the information of the image displayed on the display of the display device and the information of the sound output from the speaker of the display device.

[0022] Effects of the Invention

[0023] According to the present invention, in a display device powered by a wiring harness, a current exceeding the permissible current can be appropriately suppressed from flowing through the wiring harness. In addition, according to the present invention, in a display device powered by a wiring harness, a current exceeding the permissible current can be suppressed from flowing through the wiring harness and an image can be suppressed from being difficult to see. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram showing the structure of a vehicle equipped with a display system.

[0025] Figure 2 It is a block diagram showing the structure of a display device.

[0026] Figure 3 It is a schematic diagram for explaining an organic EL display.

[0027] Figure 4 This is a flowchart showing the flow of current-related control performed by the display device.

[0028] Figure 5 This is a flowchart showing a modification of the control related to the current executed by the display device.

[0029] Figure 6 It is a block diagram showing a modified example of the display system.

[0030] Figure 7 It is a schematic diagram for explaining a modified example of a speaker included in the display device.

[0031] Description of Reference Numerals

[0032] 1…Battery

[0033] 3. 3A…Display system

[0034] 10, 10A…Main component

[0035] 11, 21…Control Unit

[0036] 13, 23 ... display control unit (calculation unit)

[0037] 14, 24… Buffer

[0038] 15, 26…Sound processing unit

[0039] 20, 20A…Display device

[0040] 25…Display

[0041] 27, 27A…Speaker

[0042] 27A…monitor speaker

[0043] 30…Wire harness

[0044] 100…Vehicles

[0045] 251A…Display Panel DETAILED DESCRIPTION

[0046] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0047] <1. Display system>

[0048] Figure 1 1 is a schematic diagram showing the structure of a vehicle 100 equipped with a display system 3 according to an embodiment of the present invention. Specifically, the vehicle 100 is a car. The vehicle to which the present invention is applied may also be a vehicle other than a car, such as a railway vehicle. Figure 1 As shown, a battery 1 , an idling stop control unit 2 , and a display system 3 are mounted on a vehicle 100 .

[0049] The battery 1 is, for example, a lead-acid battery. The battery 1 supplies electric power to various electrical components mounted on the vehicle 100. The battery 1 is disposed in an engine room of the vehicle 100, for example.

[0050] The idling stop control unit 2 includes an electronic control device. The idling stop control unit 2 is supplied with power from the battery 1. The idling stop control unit 2 stops the engine (not shown) of the vehicle 100 based on a given stop condition, and restarts the engine of the vehicle 100 based on a given restart condition. That is, the vehicle 100 has an idling stop function.

[0051] In addition, the given stop condition is, for example, a state where the vehicle 100 is stopped and the vehicle 100 can stop idling. The state where the vehicle 100 can stop idling is, for example, a state where sufficient braking force can be maintained even when the vehicle 100 stops idling and the battery 1 has stored electricity for restarting the engine. For example, it is determined whether the vehicle 100 is stopped by a signal representing the engine speed, a signal representing the vehicle speed, etc. In addition, it is determined whether the braking force can be maintained, for example, by a signal representing the negative pressure of the brake. In addition, for example, the storage state of the battery 1 is determined by a signal representing the voltage of the battery 1.

[0052] In addition, the given restart condition is, for example, a condition for detecting an operation to restart the engine performed by the driver of the vehicle 100, or a condition for the occurrence of an event to restart the engine. For example, the operation to restart the engine performed by the driver is determined by a signal indicating the presence or absence of brake operation, a signal indicating the accelerator pedal opening, and the like.

[0053] The display system 3 includes a main unit 10 and a display device 20. The main unit 10 and the display device 20 are mounted on a vehicle 100. The main unit 10 is supplied with power from a battery 1. The main unit 10 is electrically connected to the battery 1, for example, via a wire harness. The main unit 10 may be, for example, a navigation device, an audio device, a display audio device, or an audio-integrated navigation device.

[0054] The display device 20 is connected to the main component 10 through the wire harness 30. The display device 20 is supplied with power (power supply electricity) through the wire harness 30. In addition, the power supply source is the battery 1. The wire harness 30 is a collection of wires used for power supply and wires used for signal communication in a plurality of bundles. By using the wire harness 30 as in the present embodiment, the main component 10 and the display device 20 can be easily electrically connected.

[0055] In the present embodiment, the display device 20 is a device for a so-called rear seat entertainment system (RSE) system for enjoying TV, DVD images, etc. in the rear seat in the cab of the vehicle 100. The display device 20 is arranged, for example, on the rear side of the front seats such as the driver's seat and the passenger seat, or on the roof of the cab. In the display device 20, the voltage of the battery 1 (for example, 12V) is boosted to a given voltage (for example, 24V), and the display is driven by the boosted voltage.

[0056] <2. Display device>

[0057] Figure 2 2 is a block diagram showing the structure of a display device 20 according to an embodiment of the present invention. Figure 2 As shown, the display device 20 includes a control unit 21 , an image processing unit 22 , a display control unit 23 , a buffer 24 , a display 25 , an audio processing unit 26 , and a speaker 27 .

[0058] The control unit 21 is a controller that controls the entire display device 20. In the present embodiment, the control unit 21 is, for example, a computer including a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory). In the present embodiment, the control unit 21 performs a voltage monitoring process for monitoring the voltage of the battery 1. In addition, the control unit 21 performs a current suppression process for limiting the sum of currents supplied to the display 25 and the speaker 27. In the present embodiment, the current suppression process is a process for temporarily limiting the sum of currents supplied to the display 25 and the speaker 27. The control unit 21 performs the current suppression process based on at least one of the information of the image displayed on the display 25 and the information of the sound output from the speaker 27.

[0059] According to this configuration, when it is expected that the power consumption in the self-device (display device) 20 will increase based on at least one of the video information and the audio information, current suppression processing can be performed to reduce the actual current consumption. That is, according to this configuration, it is possible to appropriately suppress the current exceeding the allowable current from flowing in the harness 30.

[0060] The voltage monitoring process and the current suppression process are functions implemented by the CPU executing arithmetic processing according to a program stored in a memory such as a ROM. The voltage monitoring process and the current suppression process will be described in detail later.

[0061] The image processing unit 22 performs various processes on the image information (image signal) input from the outside. The image processing unit 22 is an integrated circuit. The image processing unit 22 is suitable for performing, for example, image synthesis, enlargement, reduction, and color tone adjustment. The image processing unit 22 sends the processed image information to the display control unit 23 using, for example, LDVS (Low Voltage Differential Signaling).

[0062] In addition, in the present embodiment, the image information is input from the main unit 10 through a communication method such as GVIF (Gigabit Video Interface) or IEEEBUS.

[0063] The display control unit 23 controls the operation of the display 25. The display control unit 23 is, for example, an ASIC (Application Specific Integrated Circuit). In the present embodiment, the display control unit 23 is configured to include a buffer 24. Specifically, the image information output from the image processing unit 22 is input to the buffer 24. The buffer 24 temporarily stores the image information displayed on the display 25. The buffer 24 is, for example, a line buffer. In addition, the display control unit 23 and the buffer 24 may be configured separately.

[0064] In the present embodiment, the display control unit 23 obtains a calculation value related to the current consumption of the display 25 based on the pixel value information included in the information of the image stored in the buffer 24. That is, the display control unit 23 has a function as a calculation unit for obtaining a calculation value. The display device 20 includes: a calculation unit 23 for obtaining a calculation value related to the current consumption of the display 25 based on the pixel value information included in the information of the image stored in the buffer 24. The calculation value obtained in the calculation unit 23 is transmitted to the control unit 21 by, for example, communication in the SPI (Serial Peripheral Interface) method. The details of the process of obtaining the calculation value in the calculation unit 23 will be described later.

[0065] The display 25 displays an image according to the image information input from the image processing unit 22 under the control of the display control unit 23. In the present embodiment, the display 25 is an organic EL display. Figure 32 is a schematic diagram for explaining an organic EL display 25. The organic EL display 25 includes an organic EL panel 251 and a flat panel drive circuit 252. The flat panel drive circuit 252 includes a column driver 252a and a row driver 252b.

[0066] The organic EL panel 251 is driven by the column driver 252a and the row driver 252b to display images. The column driver 252a gives a signal to the signal line 253. The row driver 252b gives a signal to the scan line 254. The signal lines 253 and the scan lines 254 are arranged in a matrix in the organic EL panel 251. When the organic EL panel 251 is driven, while the row driver 252b periodically scans the M scan lines 254, the column driver 252a gives an electrical signal to the desired signal line 253 among the N signal lines 253, so that the organic EL diodes (not shown) provided at the intersections of the signal lines 253 and the scan lines 254 emit light, thereby displaying images.

[0067] On the image display surface of the organic EL panel 251, pixels 255 are arranged in a two-dimensional matrix. Each pixel 255 has a first sub-pixel 255R, a second sub-pixel 255G, and a third sub-pixel 255B. In the present embodiment, the first sub-pixel 255R displays red. The second sub-pixel 255G displays green. The third sub-pixel 255B displays blue. That is, an organic EL diode that emits light of a color corresponding to the color displayed in each sub-pixel is configured corresponding to the position of each sub-pixel 255R, 255G, and 255B. Each pixel 255 displays various colors by adjusting the brightness of these sub-pixels 255R, 255G, and 255B. The pixel value information contained in the image information, in detail, includes the pixel values ​​(brightness values) of the three sub-pixels 255R, 255G, and 255B in each pixel 255.

[0068] The number of sub-pixels and the combination of colors of each pixel 255 of the organic EL panel 251 are not limited to the configuration of this embodiment and can be changed as appropriate. For example, each pixel 255 of the organic EL panel 251 can be configured to have four sub-pixels for displaying red, green, blue, and white.

[0069] Back to Figure 2 The sound processing unit 26 performs various processes on the sound information (sound signal) input from the outside. In the present embodiment, the sound information is input from the main unit 10. The sound processing unit 26 is a DSP (Digital Signal Processor). The sound processing unit 26 adjusts the level (volume) of the input sound signal, for example, in accordance with the set volume of the speaker 27 set in the display device 20. The sound processing unit 26 outputs the processed sound information to the speaker 27.

[0070] Speaker 27 includes a speaker driving circuit (not shown) and outputs sound according to the sound information sent from sound processing unit 26. The structure of speaker 27 is not particularly limited. Speaker 27 includes, for example, a voice coil and a diaphragm vibrated by the voice coil.

[0071] In addition, at least a part of the functions implemented by the display control unit 23 and the sound processing unit 26 including the control unit 21, the image processing unit 22, and the buffer 24 can be implemented by software using a single integrated circuit such as a microcomputer. For example, in the present embodiment, a part of the functions implemented by the image processing unit 22, the display control unit 23, or the sound processing unit 26 can also be implemented by the control unit 21.

[0072] Figure 4 1 is a flowchart showing the flow of control related to current executed by the display device 20 according to the embodiment of the present invention. Figure 4 The control related to the electric current shown is continuously performed while the display device 20 is displaying images and outputting sounds. Figure 4 The control related to the electric current shown is not executed when the display device 20 is not displaying images and outputting sounds.

[0073] In step S1, monitoring of voltage, volume, and image signal is started. Voltage monitoring is monitoring of the voltage of the battery 1, and is performed by the control unit 21 to which the voltage value of the battery 1 is input. Volume monitoring is monitoring of the volume of the sound output from the speaker 27, and is performed by the control unit 21 that exchanges information with the sound processing unit 26. Image signal monitoring is performed in relation to the current consumption of the display 25. At the start of image signal monitoring, the display control unit (calculation unit) 23 starts processing to obtain a calculation value related to the current consumption of the display 25. In addition, the control unit 21 to which the calculation value is sent from the display control unit 23 starts monitoring the calculation value. When the monitoring of voltage, volume, and image signal is started, the processing proceeds to the next step S2.

[0074] Before explaining the processing of step S2, the above-mentioned calculated value related to the current consumption of the display 25 is explained. The calculated value related to the current consumption of the display 25 is obtained based on the pixel value information contained in the information of the image accumulated in the buffer 24. The display 25 composed of the organic EL panel 251 consumes more current as the brightness of the displayed image is higher. As long as the pixel value of each pixel of the displayed image is known, the current consumption can be estimated. Based on this, the calculated value related to the current consumption of the display 25 is obtained by calculation based on the pixel value of each pixel of the image displayed on the display 25. The calculated value may be the current value of the estimated current consumption itself, but it may also be a value other than the current value as long as it is a value that can estimate the current consumption of the display 25.

[0075] For example, when the buffer 24 is a line buffer, the calculated value related to the current consumption of the display 25 can be obtained as follows. The display control unit 23 sequentially obtains a line total value by adding together the pixel values ​​of each pixel 255 located on the scan line 254 (to be specific, each pixel has three pixel values ​​of RGB) for each scan line 254 of the organic EL panel 251. Then, if the display control unit 23 calculates the line total value for a certain scan line 254, it further accumulates the newly obtained line total value with the accumulated value of the line total values ​​of each scan line 254 for which the line total value was calculated previously. In addition, if the frame of the image changes, the display control unit 23 resets the accumulation. By resetting, the accumulated value returns to zero. Whenever the display control unit 23 obtains a new accumulated value in this way, it divides the new accumulated value by the white image total value obtained by summing up all the pixel values ​​of each pixel constituting one frame of image when all the pixels are white, to obtain the brightness rate (for example, expressed as a percentage).

[0076] If the brightness rate is obtained, the estimated current consumption of the display 25 can be obtained. That is, the brightness rate is one of the calculation values ​​related to the current consumption of the display 25. If the display control unit 23 obtains the brightness rate, it sends the brightness rate to the control unit 21 as a calculation value. In addition, the display control unit 23 may also send the value of the estimated current consumption obtained based on the brightness rate to the control unit 21. In addition, the display control unit 23 may be configured to send the above-mentioned integrated value to the control unit 21 as a calculation value related to the current consumption. In this case, the above-mentioned brightness rate can be obtained by the control unit 21.

[0077] In step S2, the control unit 21 checks whether the voltage of the battery 1 is below a given voltage threshold. The given voltage threshold can be determined experimentally. The given voltage threshold can be, for example, a voltage value of the battery 1 whose voltage decreases with idling stop. By determining the voltage threshold in this way, it is possible to improve the adverse condition associated with the voltage decrease of the battery 1 during idling stop.

[0078] When the voltage value of the storage battery 1 is less than the given voltage threshold (step S2 "Yes"), the control unit 21 advances the process to the next step S3. On the other hand, when the voltage value of the storage battery 1 is greater than the given voltage threshold (step S2 "No"), the control unit 21 repeats the confirmation process of step S2.

[0079] In step S3, the control unit 21 confirms whether the set volume of the sound output from the speaker 27 is greater than or equal to a given volume threshold. That is, in the present embodiment, the set volume of the speaker 27 is included in the sound information used by the control unit 21 in the current suppression process. Specifically, the control unit 21 confirms whether the set value of the volume of the sound processing unit 26 is greater than or equal to a given volume threshold. If the set value of the volume of the speaker 27 is large, the output of the speaker 27 becomes larger, and the current consumption becomes larger. For example, the given volume threshold is determined by experiments, etc., taking into account that even if the voltage of the battery 1 is reduced, the allowable current does not flow through the wiring harness 30.

[0080] For example, in the case of a configuration in which the setting value of the volume of the speaker 27 is set in stages, the given volume threshold value may be selected from the setting value of the volume. For example, in the case of a configuration in which the setting value of the volume of the speaker 27 is a number selected from "1", "2", and "3" and the larger the number, the larger the volume, the given volume threshold value may be set to "2". In this case, when the setting value of the volume of the speaker 27 is "2" or "3", the control unit 21 determines that the set volume is greater than the given volume threshold value.

[0081] If the set volume is greater than the given volume threshold (“Yes” in step S3), the control unit 21 proceeds to the next step S4. On the other hand, if the set volume is less than the given volume threshold (“No” in step S3), the control unit 21 returns to step S2.

[0082] In step S4, the control unit 21 checks whether the current consumption of the display 25 estimated from the calculated value input from the display control unit 23 is equal to or greater than a given current threshold. The control unit 21 may also be configured to convert the calculated value input from the display control unit 23 into a value of the current consumption, and check whether the converted value is equal to or greater than a given current threshold. In this case, for example, the given current threshold is determined by taking into account a given volume threshold and by experiments, etc., taking into account that the allowable current does not flow through the wiring harness 30 even when the voltage of the battery 1 decreases.

[0083] In addition, when the calculated value is the brightness rate described above, the following structure may be used: by setting a given brightness rate threshold, the calculated value and the given brightness rate threshold are compared to determine whether the current consumption of the display 25 is estimated to be above the given current threshold. The given brightness rate threshold can be determined by experiments in the same way as the given current threshold. The given brightness rate threshold is, for example, a value obtained by multiplying 100% by a number greater than zero and less than 1, assuming that all pixels constituting one frame of an image are completely white. When the given brightness rate threshold is, for example, 50%, when the brightness rate obtained as the calculated value is greater than 50%, it is estimated that the current consumption of the display 25 is greater than the given current threshold.

[0084] When it is estimated that the current consumption of the display 25 is equal to or greater than the given current threshold value based on the calculated value input from the display control unit 23 ("Yes" in step S4), the control unit 21 advances the process to the next step S5. On the other hand, when it is estimated that the current consumption of the display 25 is not equal to or greater than the given current threshold value ("No" in step S4), the control unit 21 returns the process to step S2.

[0085] In step S5, the control unit 21 performs a current suppression process to reduce the sum of the currents supplied to the display 25 and the speaker 27. That is, in the present embodiment, the control unit 21 performs the current suppression process under the condition that the current consumption of the display 25 is estimated to be above a given current threshold value and the set volume of the speaker 27 is above a given volume threshold value based on the calculated value. Accordingly, since the current suppression process is performed when it is expected that the image displayed on the display 25 is bright and the output of the speaker 27 is large, it is possible to suppress the current exceeding the allowable current from flowing through the wiring harness 30. In addition, since it is possible to set a structure that produces a change in the image of the display 25, for example, only when the image is bright and the current consumption of the display 25 is expected to be high and the set volume of the speaker 27 is high, it is possible to reduce the possibility that the user finds it difficult to see the image clearly.

[0086] In addition, in the present embodiment, the control unit 21 performs the current suppression process on the condition that the voltage of the battery 1 as the power supply source becomes less than a given voltage threshold value. That is, in the present embodiment, the current suppression process is performed when the voltage value of the battery 1 becomes less than a given voltage threshold value, and further, it is estimated based on the calculated value obtained by the display control unit 23 that the current consumption of the display 25 becomes more than a given current threshold value and the set volume of the speaker 27 is more than a given volume threshold value.

[0087] According to this, since the current supplied to at least one of the display 25 and the speaker 27 can be suppressed when the voltage of the battery 1 decreases, the reduction of the capacity of the battery 1 can be delayed. In addition, when the display device 20 uses the voltage of the battery 1 by boosting it as in the present embodiment, there is a possibility that a large current will flow through the wiring harness 30 along with the decrease in the voltage of the battery 1. However, in the present embodiment, when the voltage of the battery 1 decreases and it is expected that the consumption current of the display 25 and the speaker 27 will increase, the current suppression process is performed, so that the possibility of a current exceeding the allowable current flowing through the wiring harness 30 can be suppressed to a low level.

[0088] The current suppression process may include a process of reducing the brightness of the image displayed on the display 25. In the present embodiment, the current suppression process is a process of reducing the brightness of the display 25. Thus, the sum of the currents supplied to the display 25 and the speaker 27 can be reduced by a simple control of the control unit 21. In addition, since the brightness is reduced only when the image is bright, it is difficult to detect changes in the image.

[0089] The brightness reduction process can be achieved, for example, by reducing the ratio (duty cycle) of the lighting time of each organic EL diode controlled by PWM (Pulse Width Modulation). For example, the degree to which the duty cycle is reduced is determined by experiments. The control unit 21 instructs the display control unit 23 to reduce the duty cycle of the PWM control. The display control unit 23 changes the conditions of the PWM control according to the instruction of the control unit 21, and performs image display control under the changed conditions.

[0090] In addition, when the brightness is reduced, the brightness of all RGB colors can be reduced, but the brightness can also be reduced only for specific colors (such as red and blue) where the brightness change is difficult to feel. This can further reduce the possibility that the user finds it difficult to see the image clearly.

[0091] In addition, the current suppression process may include a process of changing the color tone of the image displayed on the display 25. In this case, a bright image can be changed to a dark image, and the sum of the currents supplied to the display 25 and the speaker 27 can be suppressed. When the color tone is changed, for example, the control unit 21 may be configured to instruct the image processing unit 22 having a function of adjusting the color tone to change the color tone. The process of changing the color tone may be performed instead of the process of reducing the brightness, or may be performed together with the process of reducing the brightness.

[0092] In addition, the current suppression process may include a process of reducing the set volume of the speaker 27. The control unit 21 instructs the sound processing unit 26 to reduce the set volume. The sound processing unit 26 changes the set value of the volume according to the instruction of the control unit 21, and processes the sound signal under the changed condition. In the case of this structure, the sum of the currents supplied to the display 25 and the speaker 27 can also be suppressed.

[0093] The process of reducing the set volume of the speaker 27 can be performed, for example, instead of the process of reducing the brightness, or can be performed together with the process of reducing the brightness. In the former case, the current suppression process limited to the sound can be performed, and the possibility that the user finds it difficult to see the image can be reduced. In the latter case, the sum of the currents supplied to the display 25 and the speaker 27 can be suppressed while balancing the use of both the image and the sound.

[0094] When the control unit 21 completes the processing of step S5, the processing proceeds to step S6. In step S6, the control unit 21 confirms whether the voltage of the storage battery 1 is below a given voltage threshold. The given voltage threshold is the same as the given voltage threshold of step S2. When the voltage of the storage battery 1 is below the given voltage threshold (step S6 "Yes"), the processing proceeds to the next step S7. On the other hand, when the voltage of the storage battery 1 is greater than the given voltage threshold (step S6 "No"), the processing proceeds to step S9.

[0095] In step S7, the control unit 21 checks whether the set volume of the speaker 27 is greater than a given volume threshold. The given volume threshold is the same as the given volume threshold of step S3. If the set volume of the speaker 27 is greater than the given volume threshold (step S7 "Yes"), the process proceeds to the next step S8. On the other hand, if the set volume of the speaker 27 is less than the given volume threshold (step S7 "No"), the process proceeds to step S9.

[0096] In step S8, the control unit 21 determines whether the estimated current consumption of the image is smaller than a given current threshold. Here, it is assumed that the given current threshold is the same as the given current threshold of step S4. The estimated current consumption of the image is the estimated current consumption of one frame of the image. For example, when the cumulative value of the row total value accumulates the amount of one frame and the brightness rate obtained based on the cumulative value is smaller than the above-mentioned given brightness rate threshold, the control unit 21 determines that the estimated current consumption is smaller than the given current threshold. In addition, when the brightness rate obtained based on the cumulative value of one frame is greater than the given brightness rate threshold, the control unit 21 determines that the estimated current consumption is greater than the given current threshold. When the control unit 21 determines that the estimated current consumption of the image is smaller than the given current threshold (step S8 "Yes"), the processing proceeds to the next step S9. On the other hand, when the control unit 21 determines that the estimated current consumption of the image is greater than the given current threshold (step S8 "No"), the processing returns to step S5. In addition, during the processing from step S6 to step S8, the current suppression is maintained.

[0097] In step S9, the control unit 21 releases the current suppression. Specifically, the control unit 21 returns the brightness reduced in step S5 to the brightness before step S5. When the process of step S9 is completed, the control unit 21 returns the process to step S2. The above process is repeated while the display device 20 displays images and outputs sounds.

[0098] According to the present embodiment, even if the accumulated value (the accumulated value of the row total value) for one frame is not stored and the brightness rate reaches a given brightness rate threshold, it is determined that the current consumption of the display 25 has become equal to or higher than a given current threshold, and current suppression processing is performed. That is, the current suppression processing can be performed with good responsiveness.

[0099] <3. Modifications>

[0100] (3-1. First Modification)

[0101] In the above-described embodiment, the current consumption of the display 25 is determined based on the amount of one frame of the image, but this is only an example. The current consumption of the display 25 may be determined based on, for example, the amount of multiple frames of the image or the amount of scan lines less than the number of scan lines of one frame.

[0102] (3-2. Second Modification)

[0103] In addition, in the above-described embodiment, the configuration is used to determine whether to perform the current suppression process based on the estimated current consumption of the display 25 and the set volume of the speaker 27, but this is only an example. For example, the control unit 21 may perform the current suppression process based on the set volume of the speaker 27 being a given volume or more as one of the conditions, and may not use the estimated current consumption of the display 25 in the determination of whether to perform the current suppression process.

[0104] For example, the control unit 21 may perform current suppression processing when the set volume of the speaker 27 is above a given volume and the voltage of the battery 1 is below a given voltage threshold. In this case, the current suppression processing may be processing for reducing the current supplied to the display 25. Thus, when it is expected that the current supplied to the self-device (display device) 20 will become high, the sum of the current supplied to the display 25 and the speaker 27 can be suppressed, thereby appropriately suppressing the current exceeding the allowable current from flowing through the harness 30. In addition, the current suppression processing may include processing for reducing the set volume in addition to processing for reducing the current supplied to the display 25. In addition, the control unit 21 may perform current suppression processing under one of the conditions that the output volume (an example of information on sound) from the speaker 27 is above a given volume threshold instead of the set volume of the speaker 27. In the case where no sound is output even when the set volume is the maximum, or when a quiet sound is output, the current suppression processing is not necessary. According to this configuration, extremely detailed current suppression processing can be performed in consideration of such occasions.

[0105] For example, when it is estimated that the current consumption of the display 25 is equal to or greater than a given current threshold and the voltage of the battery 1 is equal to or less than a given voltage threshold, the control unit 21 may suppress the current by lowering the set volume of the speaker 27 .

[0106] (3-3. Third Modification)

[0107] Figure 5 FIG. 2 is a flowchart showing a modified example of the control related to the current executed by the display device 20. Figure 5 In the modified example shown, the control unit 21 performs current suppression processing under one of the conditions that the sum of the estimated current consumption of the display 25 obtained based on the video information and the estimated current consumption of the speaker 27 obtained based on the sound information is equal to or greater than a given current consumption threshold. Figure 5 When explaining Figure 4 The same matters will be omitted unless they need special explanation.

[0108] In step S11, monitoring of voltage, audio signal, and video signal is started. The monitoring of audio signal is performed in relation to the current consumption of speaker 27. For example, in audio processing unit 26, an estimated value of the current consumption of speaker 27 is calculated based on the signal level of the audio signal temporarily stored in a buffer (not shown) and the set value of the volume. In addition, the estimated value of the current consumption can be calculated by control unit 21. Control unit 21 starts monitoring the sum of the estimated value of the current consumption of display 25 obtained based on the video signal and the estimated value of the current consumption of speaker 27.

[0109] In addition, the estimated value of the current consumption of the display 25 can be obtained based on the pixel value information included in the image information as described above. In addition, the estimated value of the current consumption of the display 25 and the estimated value of the current consumption of the speaker 27 change all the time. Therefore, the sum of the two is obtained by adding together the estimated values ​​when the timing of the display on the display 25 and the timing of the output from the speaker 27 become the same timing.

[0110] In step S12, the control unit 21 confirms whether the voltage of the storage battery 1 is below a given voltage threshold. When the voltage value of the storage battery 1 is below the given voltage threshold (step S12 "Yes"), the control unit 21 advances the process to the next step S13. On the other hand, when the voltage value of the storage battery 1 is greater than the given voltage threshold (step S12 "No"), the control unit 21 repeats the confirmation process of step S12.

[0111] In step S13, the control unit 21 checks whether the sum of the estimated value of the current consumption of the display 25 and the estimated value of the current consumption of the speaker 27 is greater than a given current consumption threshold. For example, the given current consumption threshold is determined by experiments, etc., taking into account that even if the voltage of the battery 1 decreases, the allowable current will not flow through the wiring harness 30. When the sum of the estimated values ​​of the current consumption of the display 25 and the speaker 27 is greater than the given current consumption threshold (step S13 "Yes"), the control unit 21 advances the processing to the next step S14. On the other hand, when the sum of the estimated values ​​of the current consumption of the display 25 and the speaker 27 is less than the given current consumption threshold (step S13 "No"), the control unit 21 returns the processing to step S12.

[0112] In step S14, the control unit 21 performs a current suppression process to reduce the sum of the currents supplied to the display 25 and the speaker 27. The current suppression process may be at least one of a process to reduce the current supplied to the display 25 and a process to reduce the current supplied to the speaker 27. For example, at least one of a process to reduce the brightness of the image displayed on the display 25 and a process to reduce the set volume of the speaker 27 may be performed. When the process of step S14 is completed, the process proceeds to the next step S15.

[0113] In step S15, the control unit 21 checks whether the voltage of the battery 1 is below a given voltage threshold. If the voltage of the battery 1 is below the given voltage threshold (step S15 "Yes"), the process proceeds to the next step S16. On the other hand, if the voltage of the battery 1 is greater than the given voltage threshold (step S15 "No"), the process proceeds to step S17.

[0114] In step S16, the control unit 21 determines whether the sum of the estimated values ​​of the current consumption of the display 25 and the speaker 27 is smaller than a given current consumption threshold. The given current consumption threshold is the same as the given current consumption threshold of step S13. When the control unit 21 determines that the sum of the estimated values ​​of the current consumption of the display 25 and the speaker 27 is smaller than the given current consumption threshold (step S16 "Yes"), the control unit 21 advances the processing to the next step S17. On the other hand, when the control unit 21 determines that the sum of the estimated values ​​of the current consumption of the display 25 and the speaker 27 is greater than the given current consumption threshold (step S16 "No"), the processing returns to step S15. In addition, during the processing of steps S15 and S16, current suppression is maintained.

[0115] In step S17, the control unit 21 cancels the current suppression. When the process of step S17 is completed, the control unit 21 returns the process to step S12. The above process is repeated while the display device 20 displays the image.

[0116] according to Figure 5 The structure of the present modification shown in the figure performs current suppression processing only when the sum of the current consumption of the display 25 and the speaker 27 increases, thereby reducing the possibility that the user feels that the image is difficult to see clearly or the sound is low. In addition, since the structure takes both the current consumption consumed by the display 25 and the speaker 27 into consideration, the current flowing through the harness 30 can be controlled more appropriately.

[0117] (3-4. Fourth Modification)

[0118] Figure 6 1 is a block diagram showing a modified example of the display system 3 according to the embodiment of the present invention. The display system 3A of the modified example includes a main unit 10A and a display device 20A. Figure 6 Although not described herein, the main unit 10A and the display device 20A are connected by a wire harness 30 in the same manner as in the above-described embodiment.

[0119] In the display system 3A of the modified example, the current suppression process for limiting the sum of the currents supplied to the display and the speaker of the display device 20A is performed not by the display device 20A but by the main unit 10A. For this purpose, the main unit 10A includes a control unit 11, an image processing unit 12, a display control unit (calculation unit) 13, a buffer 14, and a sound processing unit 15. Since these units 11 to 15 are respectively the same as the control unit 21, the image processing unit 22, the display control unit (calculation unit) 23, the buffer 24, and the sound processing unit 26 of the above-mentioned display device 20, detailed description thereof will be omitted.

[0120] The control unit 11 performs a current suppression process to limit the sum of the currents provided to the display and the speaker based on at least one of the information of the image displayed on the display of the display device 20A and the information of the sound output from the speaker of the display device 20A. According to this variant, when it is expected that the power consumption in the display device 20A will increase based on at least one of the information of the image and the information of the sound in the main component 10A, an instruction related to current suppression is issued from the main component 10A to the display device 20A. In this way, the current consumption in the display device 20A can be reduced. That is, according to this variant, the current that exceeds the allowable current flowing in the wiring harness 30 can be appropriately suppressed. The structure of this variant is suitable for the case where an expensive integrated circuit is not mounted in the display device 20A, etc.

[0121] (3-5. Fifth Modification)

[0122] Figure 7 2 is a schematic diagram for explaining a modified example of a speaker included in the display device 20 or 20A. Figure 7 As shown, the speaker 27A provided in the display device 20, 20A may be a display speaker that vibrates the display panel 251A (organic EL panel, etc.) provided in the display 25 to output sound. By using the speaker as a display speaker, it is possible to avoid arranging components constituting the speaker around the display panel, thereby miniaturizing the speaker.

[0123] The display speaker 27A includes an actuator drive circuit 271 and an actuator 272 in addition to the display panel 251A. The actuator drive circuit 271 includes a D / A converter and an amplifier (not shown). The D / A converter converts the digital signal (sound signal) output from the sound processing unit 26 into an analog signal. The amplifier amplifies the analog signal converted by the D / A converter to generate an actuator drive signal, and outputs the signal to the actuator 272.

[0124] The actuator 272 is driven in accordance with the actuator driving signal to vibrate the display panel 251A. Sound is outputted by the vibration of the display panel 251A based on the driving of the actuator 272. The actuator 272 may be, for example, a piezoelectric element (piezoelectric element), a solenoid, etc. The actuator 272 is disposed on the back side of the display panel 251A. The actuator 272 is fixed to the back side of the display panel 251A, for example, by means of an adhesive.

[0125] <4. Notes, etc.>

[0126] In addition to the above-mentioned embodiments, various technical features disclosed in this specification can also be modified within the scope of the technical creation. That is, the above-mentioned embodiments are all illustrative and should not be considered as limitations. The technical scope of the present invention is not shown by the description of the above-mentioned embodiments but by the claims, and should be understood to include all changes that belong to the meaning and scope equivalent to the claims. In addition, the multiple embodiments and modifications shown in this specification can be appropriately combined and implemented within the possible scope.

[0127] Furthermore, the present invention can be applied to a main assembly which is supplied with power from a battery through a wiring harness and has a function as a display device.

Claims

1. A display device mounted on a vehicle and supplied with power through a wiring harness, the display device comprising: monitor; speaker; a control unit that performs a current suppression process for reducing a sum of currents supplied to the display and the speaker relative to an allowable current of the wiring harness based on information of an image displayed on the display and information of a sound output from the speaker; A buffer temporarily storing the image information; and a calculation unit that obtains a calculation value related to the current consumption of the display based on pixel value information included in the information of the image accumulated in the buffer; The sound information includes the set volume of the speaker. The control unit performs the current suppression process under one of the conditions that it is estimated based on the calculation value that the current consumption of the display is equal to or greater than a given current threshold and the set volume is equal to or greater than a given volume threshold.

2. The display device according to claim 1, characterized in that The current suppression process includes a process of reducing the current supplied to the display.

3. The display device according to claim 1, characterized in that The sound information includes the output volume from the speaker. The control unit performs the current suppression process under one of the conditions that the output volume is greater than a given volume threshold, The current suppression process includes a process of reducing the current supplied to the display.

4. The display device according to claim 1, characterized in that The image information includes the brightness of the display. The control unit performs the current suppression process under the condition that the brightness is greater than or equal to a given brightness threshold. The current suppression process includes a process of reducing the current supplied to the speaker.

5. The display device according to claim 1, characterized in that The control unit performs the current limiting process on one of the conditions that a sum of an estimated current consumption of the display obtained based on the video information and an estimated current consumption of the speaker obtained based on the audio information is equal to or greater than a given current consumption threshold.

6. The display device according to any one of claims 1 to 5, characterized in that: The control unit performs the current limiting process on the condition that the voltage of a storage battery serving as a supply source of the power source becomes equal to or lower than a predetermined voltage threshold.

7. The display device according to any one of claims 1 to 5, characterized in that: The current suppression process includes a process of reducing the volume of the speaker.

8. The display device according to any one of claims 1 to 5, characterized in that: The current suppression process includes a process of reducing the brightness of an image displayed on the display.

9. The display device according to any one of claims 1 to 5, characterized in that: The current suppression process includes a process of changing the color tone of an image displayed on the display.

10. The display device according to any one of claims 1 to 5, characterized in that: The speaker is a display speaker that vibrates a display panel included in the display to output sound.

11. The display device according to any one of claims 1 to 5, characterized in that: The display device is connected to a main component mounted on the vehicle through the wiring harness.

12. A display system, characterized in that: have: A main assembly, mounted on a vehicle; A display device having a display, connected to the main assembly via a wiring harness and supplied with power via the wiring harness, A buffer temporarily storing the image information; and a calculation unit that obtains a calculation value related to the current consumption of the display based on pixel value information included in the information of the image accumulated in the buffer; The sound information includes the set volume of the speaker. The control unit performs the current suppression process under one of the conditions that the current consumption of the display is estimated to be equal to or greater than a given current threshold value and the set volume is equal to or greater than a given volume threshold value, based on the calculated value. The main component includes: a control unit that performs current suppression processing to reduce the sum of currents supplied to the display and the speaker relative to the allowable current of the wiring harness based on information of images displayed on the display of the display device and information of sounds output from the speaker of the display device.

13. A display control method for a display device mounted on a vehicle and supplied with power via a wiring harness, wherein: Based on information of an image displayed on a display of the display device and information of a sound output from a speaker of the display device, a current suppression process is performed to reduce a sum of currents supplied to the display device and the speaker relative to an allowable current of the wiring harness, temporarily storing the image information, obtaining a calculated value related to the current consumption of the display based on pixel value information included in the information of the image stored in the buffer, The sound information includes the set volume of the speaker. The current suppression process is performed under one of the conditions that it is estimated based on the calculation value that the current consumption of the display is equal to or greater than a given current threshold and the set volume is equal to or greater than a given volume threshold.

Images