JP2009123284A - Electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic device capable of instantaneously operating a HDMI (High Definition Multimedia Interface) signal processing part when a CEC (Consumer Electronics Consumer) signal is received. <P>SOLUTION: The electronic device includes a switch means connected between the output line of a standby voltage generated by a power supply part and a signal processing integrated circuit, and power is supplied to the signal processing integrated circuit only when a control signal is input. Also, the electronic device includes an input/output separation circuit of a control signal inside the signal processing integrated circuit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an electronic device capable of controlling an externally connected electronic device according to the HDMI (High Definition Multimedia Interface) standard, and more particularly to detecting an externally connected electronic device and detecting an externally connected electronic device. The present invention relates to an electronic device that realizes power saving by performing power control in a standby state and a power-on state in accordance with a control signal from the device.

Conventionally, technologies for reducing the power consumption of electrical products have been studied in consideration of environmental problems. Among these technologies, the power supply output voltage is controlled in a power-on state in which all functions of the electrical product are operable and in a standby state waiting for a power-on command. In general, a technique for realizing low power consumption by supplying only electric power is used. In addition to the CPU (Central Processing Unit) that controls the overall operation of the electrical product, a sub CPU that receives only a power-on signal from the user and controls the power supply is provided. There is also widely used a technique of supplying only the power for operating the device and suppressing the power consumption during standby.

On the other hand, in recent years, in a video / audio reproduction system in which a plurality of electronic devices are connected, a technique for controlling a plurality of electronic devices connected to one electronic device via a connected cable has been standardized. Yes. One of the standards is the HDMI standard. In the HDMI standard, for example, it is possible to multiplex a digital audio signal during a blanking period of the digital video signal and perform audio transmission, in addition to transmitting the digital video signal in the form of an RGB signal, a YCbCr signal It can be transmitted in the form of YPbPr signals with higher image quality than that, and can be connected with a small HDMI terminal comparable to a USB (Universal Serial Bus), etc. It is.

Further, the HDMI standard can handle not only video signals and audio signals but also signals for communication between devices connected via HDMI terminals. Hot plug terminal for outputting information on whether the power is currently turned on, for outputting the status of the device other than the power information, or for sending a signal for controlling the other device with one device There is a CEC (Consumer Electronics Control) terminal. This CEC terminal is a terminal for sending and receiving commands such as power control between electronic devices, and basic operation commands such as playback, fast forward, skip, and stop can be controlled between products of different electronic device manufacturers. As such, it is defined as a standard by the HDMI standard. Furthermore, the HDMI standard includes an extended area that can be freely defined by each electronic device manufacturer. By extending the control program, control can be performed using a control command unique to each electronic device manufacturer.

An HDMI signal processing unit is required to input / output video / audio signals between connected electronic devices in accordance with the HDMI standard, and to perform mutual control between electronic devices using a CEC signal. In addition, in order to receive a CEC signal from an externally connected electronic device and perform an operation according to the CEC signal, the CEC signal is received regardless of the operation state of the electronic device in the standby state or the power-on state. The HDMI signal processing unit must be able to operate. In order to enable the HDMI signal processing unit to operate at any time, supplying power to the HDMI signal processing unit in both the standby state and the power-on state always ensures that the HDMI signal processing unit does not need to be controlled by the CEC signal. Electric power is consumed in the processing unit, which hinders reduction in power consumption of the electronic device.

FIG. 4 shows a block diagram in the prior art that can always perform control by the CEC signal and realize low power consumption. The power supply unit 401 generates a voltage necessary for the operation of the electronic device, and the sub CPU 402 performs a power-on state and a standby state of the power supply unit 401 in accordance with a power-on or power-off command input from the user via the remote controller 403. To control. In the standby state, the power supply unit 401 outputs only EVER3.3V, the EVER3.3V is supplied to the sub CPU 402, and the sub CPU 402 always monitors a command from the user to set the power supply unit 401 to power on. An electronic device is connected to the HDMI connection terminal 404 via an HDMI cable (not shown), and the hot plug terminal 405 of the HDMI connection terminal 404 is 5 V when the externally connected electronic device is powered on. It is defined in the HDMI standard so that a voltage is output. Also, the CEC input / output terminal 406 of the HDMI connection terminal 404 is a terminal for inputting / outputting a CEC signal between the electronic device and the externally connected electronic device, and the externally connected electronic device is powered on. In such a case, the CEC control program is generally designed to be extended so that a command for powering on the electronic device at the same time as the power on is output from the electronic device connected to the outside. is there.

Next, the CEC signal representing the power-on command is received by the CEC input / output terminal 406 of the HDMI connection terminal 404. The received CEC signal is input to the input / output separation circuit 407 and received by the CEC input terminal 414 of the sub CPU 402. The input / output separation circuit 407 is a circuit for separating the input / output signal of the CEC input / output terminal 406 of the HDMI connection terminal 404 into an input signal and an output signal, and includes four transistors T401 to T404 and a plurality of resistors and capacitors. Consists of. When receiving the CEC signal from the CEC input terminal 414, the sub CPU 402 outputs a power-on signal to the power supply unit 401, and the power supply unit 401 outputs power-on 3.3V. The power supply to the HDMI signal processing integrated circuit 409 is supplied from power-on 3.3V.

On the other hand, when 5 V is output to the hot plug terminal 405, the transistor T405 is turned on, and EVER 3.3 V is applied to the hot plug detection terminal 12 of the HDMI signal processing integrated circuit 409. The HDMI signal processing integrated circuit 409 starts operation when a power-on voltage of 3.3 V is supplied and a signal is detected at the hot plug detection terminal 412, and converts the video / audio signal into data compliant with the HDMI standard. / Output from the audio data output terminal 415 and output from the video / audio data output terminal 413 of the HDMI connection terminal 404 to an externally connected electronic device. The CEC output terminal 416 of the sub CPU 402 outputs a CEC signal for controlling an externally connected electronic device. The output CEC signal is input to the input / output separation circuit 407 and output from the CEC input / output terminal 406 of the HDMI connection terminal 404 to an externally connected electronic device.

As described above, the sub CPU 402 powers on the power supply unit 401 when receiving a CEC signal from an electronic device connected to the outside, and supplies power-on 3.3 V to the HDMI signal processing integrated circuit 409. Realizes power consumption. That is, using the fact that the sub CPU 402 controls the power on / off of the power supply unit 401, power is supplied to the HDMI signal processing unit 409 only when the CEC signal is received in the standby state, and the HDMI signal processing unit 409 is supplied. The case of supplying power to is limited.

In the prior art, since the input / output separation circuit of the CEC signal is composed of a plurality of transistors, it is necessary to design in consideration of variations in the characteristics of the transistors, and therefore, it is necessary to use transistors with small variations. Therefore, the part cost has increased. Further, since power is supplied to the HDMI signal processing unit using the sub CPU, it takes time to supply power to the HDMI signal processing unit, and a time lag occurs until the HDMI signal processing unit operates. The problem remained.

The present invention has been made in view of such a problem, and lowers the manufacturing cost and improves the quality of a CEC signal input / output separation circuit, and operates an HDMI signal processing unit instantaneously when a CEC signal is received. An object of the present invention is to provide an electronic device that can be used.

To achieve the above object, in an electronic device, a power supply unit that outputs a standby voltage and a power-on voltage to an operation unit via a voltage output line, a sub CPU that sets an output voltage of the power supply unit, and a power-on An interface for receiving a command and a power-off command; a signal processing integrated circuit for processing a video / audio source connected to a power supply unit through a voltage output line; and an electronic device connected to the outside by the signal processing integrated circuit Outputs processed video / audio signals and inputs / outputs control signals to / from the externally connected electronic device and a power-on detection terminal for detecting that the externally connected electronic device is powered on The sub CPU transmits control signals to the externally connected electronic device. A voltage output line for a standby voltage generated by the power supply unit and the signal processing integrated circuit, and an input terminal for inputting a control signal from the electronic device connected to the outside The sub CPU sets the power supply unit to generate a standby voltage until the interface receives a power-on command. When the interface receives a power-on command The power supply unit is set to generate a power-on voltage, and the signal processing integrated circuit includes an input / output separation circuit for the control signal, and the input / output separation circuit outputs from the electronic device connected to the outside The control signal received by the input / output separation circuit is output to the sub CPU, and the sub CPU When the control signal is received, the power supply unit is set to generate a power-on voltage, and when it is detected that an electronic device connected to the outside from the detection terminal is powered on, the switch unit is turned on to Power is supplied to the signal processing integrated circuit.

In the electronic device, the signal processing unit converts the video / audio source into a signal that conforms to the HDMI (High Definition Multimedia Interface) standard.

In the electronic device, the connection terminal includes a video / audio signal output terminal compliant with the HDMI standard, a hot plug terminal, and a CEC (Consumer Electronics Consumer) input / output terminal.

By configuring as described above, only when the externally connected electronic device is in the power-on state, power is supplied to the HDMI signal processing unit, and the power consumption of the electronic device is suppressed.

According to the first aspect of the present invention, the switch means is connected between the output line of the standby voltage generated by the power supply section and the signal processing section, and the switch means is connected to an external electronic device. Since the standby voltage is supplied to the signal processing unit only when it is detected that the power is turned on, power consumption is limited so that the signal processing unit operates only when mutual control is performed with an externally connected electronic device. As a result, the power consumption of the electronic device can be suppressed. In addition, by directly turning on and off the switch means by the output signal from the detection terminal for detecting that the electronic device connected to the outside is powered on, the signal processing is performed immediately after the signal is output from the detection terminal. It is possible to supply power to the unit. In addition, by integrating a control signal input / output separation circuit, which has conventionally been composed of a plurality of transistors, in a signal processing integrated circuit, manufacturing costs can be reduced. In addition, since the input / output separation circuit in the prior art is composed of a plurality of transistors, there are as many transistor variations as the number of transistors. There is also a possibility that the separation function which is the function of the above will malfunction. In order to avoid this, a transistor having a small quality variation and a high quality performance rank must be used, which increases the cost. According to the first aspect of the present invention, in designing an electronic device by integrating an input / output separation circuit in a signal processing integrated circuit, only a variation in one part of a semiconductor IC having the signal processing integrated circuit is considered. Since design development or management is sufficient, the development period of electronic equipment can be shortened, the accuracy of separating input / output signals can be improved, and erroneous determination of control signals can be reduced. .

According to the second aspect of the present invention, the signal processing integrated circuit is a processing integrated circuit in which the video / audio source is a signal compliant with the HDMI (High Definition Multimedia Interface) standard, so that a blanking period of the digital video signal is obtained. It is possible to multiplex digital audio signals and perform audio transmission. Using the CEC conforming to the HDMI standard, it is possible to detect the operation state between devices connected by a connection terminal conforming to the HDMI standard. In addition, it is possible to control the operation of each device between devices connected by connection terminals compliant with the HDMI standard.

According to the third aspect of the present invention, the connection terminal is an HDMI connection terminal conforming to the HDMI standard, so that the digital video signal is transmitted in the form of an RGB signal, or in the form of a YCbCr signal. It is possible to transmit in the form of a high quality YPbPr signal. Further, it is possible to connect with a small connector comparable to a USB (Universal Serial Bus). In addition, it is possible to detect an operation state between devices connected by a connection terminal compliant with the HDMI standard by using CEC compliant with the HDMI standard. In addition, it is possible to control the operation of each device between devices connected by connection terminals compliant with the HDMI standard.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an optical disk reproducing apparatus according to the present invention and a television receiving apparatus connected thereto. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The optical disc playback apparatus 100 reads the recorded data when an optical disc 101 such as a DVD is mounted on the drive unit 102. Then, the data read by the drive unit 102 is supplied to the signal processing unit 103 and subjected to digitization processing, error correction processing, decoding processing, and the like in order, and is restored to a digital video signal and audio signal. The

Thereafter, the digital video signal and audio signal restored by the signal processing unit 103 are supplied to the HDMI signal processing integrated circuit 104 and converted into a format conforming to the HDMI standard, and are expressed by a one-dot chain line. Is output to the outside. The DVD HDMI terminal 111 transmits and receives control signals for mutual control with a video output terminal 105 for outputting video data, an audio output terminal 106 for outputting audio data, and an externally connected device. The control input / output terminal 107 is used to

In the optical disc playback apparatus 100, all the operations including the above-described playback operation are comprehensively controlled by the main CPU. The main CPU 108 receives operation information from the operation unit 109 which is a group of switches provided in the main body of the optical disc playback apparatus 100, or receives operation information sent from the remote-controllable remote controller 110 via the light receiving unit 113. Each part is received and controlled so that the operation content is reflected.

The power supply unit 114 generates a standby voltage required when the optical disc apparatus 100 is in a standby (standby) state and a power-on voltage required when in a power-on (operation) state. Also, the sub CPU 115 performs switching setting between the standby voltage and the power-on voltage of the power supply unit 114, monitors the power-on signal from the operation unit 109 or the remote controller 110, and generates the power-supply unit 114 when receiving the power-on signal. The output voltage to be boosted is increased from the standby voltage to the power-on voltage, and the optical disc reproducing apparatus 100 is shifted from the standby state to the power-on state.

The standby voltage is supplied only to a circuit that requires an operation in order for the optical disc playback apparatus 100 to shift from the standby state to the power-on state. With this configuration, power consumption during standby is suppressed. Yes. A standby voltage is also supplied to the sub CPU 115, and a power-on signal from the operation unit 109 or the remote controller 110 is constantly monitored.

The main CPU 108 uses the memory unit 112. The memory unit 112 mainly includes a ROM (Read Only Memory) that stores a control program executed by the main CPU 108, a RAM (Random Access Memory) that provides a work area for the CPU, various setting information, control information, and the like. Is stored in a non-volatile memory.

Here, the video output terminal 105, the audio output terminal 106, and the control input / output terminal 107 are each provided in a liquid crystal television receiver 120 serving as a signal receiver via a transmission line compliant with the HDMI standard. , And is connected to an HDMI terminal 134 represented by a one-dot chain line. The HDMI terminal 134 includes a video input terminal 121 for receiving video data output from the HDMI terminal 111 of the optical disc apparatus 100, an audio input terminal 122 for receiving audio data, and the television receiver 120 and the optical disc apparatus 100. It comprises a control input / output terminal 123 for transmitting / receiving control data for performing mutual control between them.

Among these, the digital video data supplied to the video input terminal 121 is supplied to the HDMI signal processing unit 124, returned to the digital video signal before being converted into the HDMI standard, and then supplied to the video processing unit 125. Then, the image is converted into a form corresponding to the display, and the image is displayed by the image display unit 126 including a liquid crystal panel or the like.

The digital audio data supplied to the audio input terminal 122 is supplied to the HDMI signal processing unit 124 and returned to the digital audio signal before conversion by the HDMI signal processing integrated circuit 104 of the optical disc playback apparatus. The sound is supplied to the sound processing unit 127 and amplified to a form corresponding to sound reproduction, and the sound is reproduced by the speaker 128.

Further, the CPU 130 of the television receiving device receives operation information from the operation unit 131 that is a switch group provided in the main body of the television receiving device 120, or receives operation information sent from the remote-controllable remote control 132. Receiving via the light receiving unit 133, each unit is controlled to reflect the operation content. The memory unit 129 mainly includes a ROM (Read Only Memory) that stores a control program executed by the CPU 130, a RAM (Random Access Memory) that provides a work area for the CPU, and an image quality adjustment value and a volume that are arbitrarily set by the user. And a non-volatile memory in which various setting information such as adjustment values, control information, and the like are stored.

Next, FIG. 2 shows the pin arrangement of HDMI terminals, which are connection terminals compliant with the HDMI standard, and the signal names of the respective pins. In the HDMI standard, for example, it is possible to multiplex a digital audio signal during a blanking period of the digital video signal and perform audio transmission, in addition to transmitting the digital video signal in the form of an RGB signal, a YCbCr signal It can be transmitted in the form of YPbPr signal of higher quality or higher, and it can be connected with a small HDMI connector similar to USB (Universal Serial Bus), etc. It is.

The HDMI terminal can handle not only a video signal and an audio signal but also a signal for communication between devices connected by the HDMI terminal. To output a hot plug terminal 201 for outputting information on whether or not the power supply is currently turned on, a status of a device other than the power supply information, and a signal for controlling the other device by one device CEC terminal 202 is provided. The hot plug terminal is defined by the HDMI standard so that a voltage of 5 V is output when an externally connected electronic device is powered on. The CEC terminal is a terminal for sending and receiving commands such as power control between electronic devices, and basic operation commands such as playback, fast forward, skip, and stop can be controlled between products of different electronic device manufacturers. Therefore, it is defined as a standard by the HDMI standard. Furthermore, the HDMI standard includes an extended area that can be freely defined by each electronic device manufacturer. By extending the control program, control can be performed using a control command unique to each electronic device manufacturer.

Next, FIG. 3 shows a main block diagram of the electronic apparatus (FIG. 1) according to the present invention. The operation of the electronic device in the embodiment of the present invention will be described with reference to FIG. The power supply unit 114 outputs EVER3.3V, which is a standby voltage in a standby state, and outputs P-ON3.3V, which is a power-on voltage, in a power-on state in which all operations of the electronic device are possible.

The sub CPU 115 sets a standby voltage and a power-on voltage that are output voltages of the power supply unit 114 in accordance with a power-on / off command from the remote controller 110. The sub CPU 115 also outputs a CEC input terminal 305 for inputting a CEC signal from an electronic device connected to the outside, and a CEC signal output for outputting a CEC signal for controlling the electronic device connected to the outside. A terminal 306 is provided. When the CEC signal input from the CEC input / output terminal 303 of the HDMI connection terminal 301 is received via the HDMI signal processing integrated circuit 104 in the standby state, the power-on voltage is output to the power supply unit 114. Set as follows.

The HDMI signal integrated circuit 104 receives a video / audio signal from a video / audio source (not shown), is converted into video / audio data compliant with the HDMI standard, and outputs it from the video / audio data output terminal 307. As described with reference to FIG. 1, the video / audio data output terminal 307 actually has separate output terminals for video data and audio data, but in FIG. 3, it is a single output terminal for simplification. . Further, the HDMI signal processing integrated circuit 104 has a hot plug detection terminal 308 for receiving a signal indicating that an electronic device connected to the outside is powered on. In addition, a CEC input / output terminal 314 for inputting / outputting a CEC signal for performing mutual control with an electronic device connected to the outside is provided. In addition, a CEC input terminal 309 for inputting a CEC signal from the sub CPU 115 and a CEC output terminal for outputting a CEC signal received from an electronic device externally connected to the sub CPU 115 are provided. Further, the HDMI signal processing integrated circuit 104 has a power supply terminal 311 for receiving power necessary for operation.

Here, the CEC signal input / output terminal 303 included in the HDMI connection terminal 301 is an input / output terminal that serves both as an input and an output because the HDMI connection terminal is miniaturized and conforms to the HDMI standard. is there. On the other hand, the sub CPU 115 has a CEC signal input terminal and an output terminal separately. Since the input / output terminals serve as both signal input and output, signal input and output cannot be performed simultaneously. Further, when receiving the input, the sub CPU 115 must at least go through a processing procedure of signal input processing, determination of whether the signal is correct, and output of the determination result. For this reason, the input and output signals cannot be processed at the same time, and the number of processing procedures increases, so that one process takes time. In addition, since input and output cannot be processed simultaneously, interrupt processing that performs processing with priority on a signal having a high priority cannot be performed. In order to improve these, it is necessary to improve the performance of the sub CPU 114 in order to shorten the processing time, which increases the manufacturing cost. Therefore, the sub CPU 114 is provided with a CEC input terminal 305 and a CEC output terminal 306 separately.

The HDMI connection terminal 301 is a connection terminal conforming to the HDMI standard, is connected to an external electronic device (not shown), and outputs a signal indicating that the externally connected electronic device is powered on. A CEC signal for controlling an externally connected electronic device, a CEC input / output terminal 303 for inputting a CEC signal from the externally connected electronic device, and a video / A video / audio data output terminal 304 for outputting audio data is provided.

As described above, the CEC input / output terminal 303 in the HDMI connection terminal 301 is a terminal that also serves as an input / output, whereas the sub CPU 115 enables the response speed to the CEC signal and enables interrupt processing. For this reason, a CEC input terminal 305 and a CEC output terminal 306 are provided, and a CEC signal cannot be input / output without change. Therefore, an input / output separation circuit 312 for separating a CEC input / output signal from the CEC input / output terminal 303 is provided inside the HDMI signal processing integrated circuit 104. The circuit of the input / output separation circuit 312 is equivalent to 407 in FIG. 4 representing the prior art. In the prior art, in the input / output separation circuit 407, four transistors and a plurality of resistors and capacitors are individually configured on a circuit board. In order to ensure separation of input and output signals, it is necessary to design in consideration of variations in electrical characteristics of electronic components. However, if the number of electronic components is large as in the prior art, the variation of each electronic component The parts must be set in consideration of the above. In particular, the characteristics of a transistor, which is a semiconductor element, vary greatly depending on the current and temperature. Therefore, when it is configured with four transistors, it is necessary to select a high-quality product with small variations, which increases the manufacturing cost. I will let you. In the present invention, by integrating these electronic components inside the HDMI signal processing integrated circuit 104, it becomes possible to perform quality control by comprehensively varying the plurality of electronic components, and the input / output separation accuracy is also improved. The manufacturing cost can be reduced by reducing the number of components and reducing the circuit board.

Next, an operation for shifting from the standby state to the power-on state will be described. In the standby state, the power supply unit 114 generates the standby voltage EVER3.3V, and the sub CPU 115 is supplied with the EVER3.3V, and can output a power-on signal for causing the power supply unit 114 to generate the power-on voltage. Is in a state. In the standby state, when an externally connected electronic device is powered on, a predetermined voltage is output to the hot plug terminal 302 of the HDMI connection terminal 301 by the externally connected electronic device. Zero V is output when an externally connected electronic device is in a standby state, and 5 V is output when the electronic device is in a power-on state. The 5 V voltage output to the hot plug terminal 302 is divided by the voltage dividing resistors R301 and R302. The divided voltage is applied to the base of the transistor T301, and the collector-emitter of the transistor T301 is conducted. EVER3.3V is connected to the base of the transistor T302 via the current limiting resistor R303, and the collector-emitter of the transistor T302 is conductive. However, the transistor T301 is conductive by the output voltage of the hot plug terminal 302. The base potential of the transistor T302 is almost zero,
The collector-emitter of the transistor T302 is turned off.

Between the power supply terminal 311 of the HDMI signal processing integrated circuit 104 and the EVER3.3V, switch means 313 for turning on / off the supply of the EVER3.3V to the HDMI signal integrated circuit 104 is provided. The switch means 313 includes a transistor T303, a bias resistor R304, and a current limiting resistor R305, and is turned on / off according to the output voltage of the hot plug terminal 302. When no voltage is output to the hot plug terminal 302, since EVER3.3V is applied to the base of the transistor T302, the base potential of the transistor T303 is also 3.3V, and the emitter-collector of the transistor T303 is turned off. Thus, EVER3.3V is not supplied to the power supply terminal 311 of the HDMI signal processing integrated circuit 104.

When a voltage of 5 V is output to the hot plug terminal 302 and the collector-emitter of the transistor T301 is conducted, the collector potential of the transistor T301 becomes almost zero and the base potential of the transistor T303 becomes almost zero. -The collector is made conductive, and EVER3.3V is supplied to the power supply terminal 311.

Further, EVER3.3V is applied to the hot plug detection terminal 308 of the HDMI signal processing integrated circuit 104 via the current limiting resistor R304, but when the collector-emitter of the transistor T302 is ON, the hot plug is detected. The potential of the detection terminal 308 is almost zero. By turning on T301 and turning off T302 according to the output voltage of the hot plug terminal 302, EVER3.3V is applied to the hot plug detection terminal 308.

As described above, the HDMI signal processing integrated circuit 104 is supplied with the power supply voltage EVER3.3V required for the operation of the HDMI signal integrated circuit 104 according to the output voltage of the hot plug terminal 302 and is connected to the outside. By detecting that the electronic device is powered on, the operation shifts to a ready state in which operation control by CEC is possible at any time.

A CEC signal indicating power-on is output from the CEC input / output terminal 303 of the HDMI connection terminal 301 and input to the CEC input / output terminal 314 of the HDMI signal processing integrated circuit 104. The input CEC signal is output from the CEC output terminal 310 to the sub CPU 115 via the input / output separation circuit 312 provided in the HDMI signal processing integrated circuit 104. The sub CPU 115 receives the CEC signal from the HDMI signal processing integrated circuit 104 at the CEC input terminal 305 and sends a power-on signal to the power supply unit 114. The power supply unit 114 receives the power-on signal from the sub CPU 115, boosts the output voltage from the standby voltage to the power-on voltage, and the electronic device shifts to a power-on state in which all operations are possible.

As described above, the switch unit is connected between the output line of the standby voltage generated by the power supply unit and the signal processing unit, and the switch unit detects that the electronic device connected to the outside is powered on. Since the standby voltage is supplied to the signal processing unit only, the power consumption is limited so that the signal processing unit operates only when mutual control is performed with an externally connected electronic device. In addition, even in the standby state, it is possible to always shift to the power-on state in accordance with a control signal from an electronic device connected to the outside.

In the prior art, a CEC signal received from an externally connected electronic device is input to the sub CPU, and the sub CPU generates a power-on voltage in the power supply unit, and this power-on voltage is input to the HDMI signal processing integrated circuit. Therefore, it takes time until the HDMI signal processing integrated circuit operates after the CEC signal is output from the externally connected electronic device. However, in the present invention, a signal is output from the detection terminal by directly turning on / off the switch means for supplying power to the HDMI signal processing integrated circuit by the output signal from the detection terminal for detecting the power-on. Therefore, it is possible to immediately supply power to the signal processing unit. In addition, by integrating the control signal input / output separation circuit, which has conventionally been composed of a plurality of transistors, inside the signal processing integrated circuit, the number of electronic components can be reduced, and the circuit board can be made smaller, thereby reducing the manufacturing cost. Can be reduced. Further, since the input / output separation circuit in the prior art is composed of a plurality of transistors, there are as many variations as there are transistors, and when the variations of individual transistors are combined, There is also a possibility that the separation function which is the function of the above will malfunction. In order to avoid this, a transistor having a small quality variation and a high quality performance rank must be used, which increases the cost. According to the first aspect of the present invention, in designing an electronic device by integrating an input / output separation circuit in a signal processing integrated circuit, only a variation in one part of a semiconductor IC having the signal processing integrated circuit is considered. Since design development or management is sufficient, the development period of electronic equipment can be shortened, the accuracy of separating input / output signals can be improved, and erroneous determination of control signals can be reduced. .

The present invention is suitable for an electronic device having a control circuit for mutually controlling the electronic devices, and particularly suitable for an electronic device that realizes power saving by limiting power supply to the control circuit.

1 is a block diagram of an optical disk reproducing device and a television receiving device connected thereto according to the present invention. The pin arrangement of the HDMI terminal which is a connection terminal compliant with the HDMI standard according to the present invention and the signal name of each pin are shown. The main block diagram in the electronic device which concerns on this invention is represented. The block diagram in a prior art is shown.

Explanation of symbols

100 Electronic Device 104 Signal Integrated Circuit 114 Interface 115 Sub CPU
301 connection terminal 312 input / output separation circuit 313 switch means

Claims (3)

A power supply unit that outputs a standby voltage and a power-on voltage to the operation unit via a voltage output line; a sub CPU that sets an output voltage of the power supply unit; an interface that receives a power-on command and a power-off command; A signal processing integrated circuit for processing a video / audio source connected through a voltage output line, and a video / audio signal processed by the signal processing integrated circuit to an electronic device connected to the outside, and the external And a connection terminal having an input / output terminal for inputting / outputting control signals to / from the externally connected electronic device. The sub CPU is connected to the outside and an output terminal for outputting a control signal to the electronic device connected to the outside. An electronic device having an input terminal for inputting a control signal from the electronic device,
Switch means is provided between the voltage output line of the standby voltage generated by the power supply unit and the signal processing integrated circuit, and the sub CPU generates a standby voltage until the interface receives a power-on command. The power supply unit is set, and when the interface receives a power-on command, the power-supply unit is set to generate a power-on voltage, and the signal processing integrated circuit includes an input / output separation circuit for the control signal The input / output separation circuit receives a control signal output from the electronic device connected to the outside, and outputs the control signal separated by the input / output separation circuit to the sub CPU. When the control signal is received, the power supply unit is set to generate a power-on voltage, and is connected to the outside from the detection terminal. And when the electronic device detects that it has powered on, the electronic device and supplying power to the signal processing integrated circuit by turning on the switch means. The electronic device according to claim 1, wherein the signal processing integrated circuit converts a video / audio source into a signal that conforms to a High Definition Multimedia Interface (HDMI) standard. The electronic device according to claim 1, wherein the connection terminal includes a video / audio signal output terminal compliant with the HDMI standard, a hot plug terminal, and a CEC (Consumer Electronics Consumer) input / output terminal.