JP3663074B2 - Signal output device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention can be applied to analog signal processing equipment such as a TV monitor to display video on a video equipment having an analog signal output terminal and a digital signal output terminal, such as a digital still camera, and various information processing. The present invention relates to a signal output device for connecting a digital signal processing device such as a personal computer to be executed. In particular, it has a common jack for connecting an analog signal processing device and a digital signal processing device, and depends on the device connected to the jack. The present invention relates to a signal output device for outputting an analog signal to an analog signal processing device and outputting a digital signal to a digital signal processing device.
[0002]
[Prior art]
Conventionally, in a digital still camera, as shown in FIG. 3, a communication jack (2) to be connected to a digital signal processing device such as a personal computer and an image to which an analog signal processing device such as a TV monitor is connected. An output jack (3) is provided. An analog signal output terminal VIDEO for outputting an analog signal such as a video signal and a digital signal such as a control signal are input to the main circuit (1). An input terminal RXD, a digital signal output terminal TXD for outputting a digital signal such as a control signal, and the like are provided.
[0003]
The analog signal output terminal VIDEO is connected to the input terminal J3 of the video output jack (3) via the line driver (8).
The digital signal input terminal RXD and the digital signal output terminal TXD are connected to the output terminal JI and the input terminal J2 of the communication jack (2), respectively, via the RS232C transceiver (4).
[0004]
Although the digital signal (control signal) output from the digital signal output terminal TXD has an amplitude of 0 to 3.3 V, the RS232C standard requires an amplitude of ± 5 V to ± 15 V. In the circuit, a signal of 0 to 3.3 V is boosted to an amplitude of ± 5.4 using a voltage of ± 6 V obtained from the charge pump (5) in the RS232C transceiver (4), and a communication jack ( Sending to 2).
[0005]
The analog signal (video signal) output from the analog signal output terminal VIDEO has an amplitude of ± 1 V, and the signal includes a line driver (8), a DC blocking capacitor C, and an impedance matching resistor RX. Then, it is supplied to the terminal J3 of the video output jack (3).
[0006]
Accordingly, by connecting a personal computer, for example, to the communication jack (2), data communication can be performed between the digital still camera and the personal computer. For example, the digital still camera is controlled by the personal computer, or digital A digital video signal output from a still camera can be supplied to a personal computer to perform processing such as editing an image.
Further, by connecting, for example, a TV monitor to the video output jack (3), it is possible to display an image taken with a digital still camera on the TV monitor.
[0007]
[Problems to be solved by the invention]
However, in a conventional digital still camera, a digital signal processing device such as a personal computer is connected to the communication jack (2), and an analog signal processing device such as a TV monitor is connected to the video output jack (3). In spite of the fact that both devices cannot be operated at the same time, the communication jack (2) and the video output jack (3) are provided separately. It was.
[0008]
Accordingly, an object of the present invention is to provide an analog signal processing device that should receive an analog signal output from the main circuit and a digital signal output from the main circuit, with respect to the main circuit having the analog signal output terminal and the digital signal output terminal By providing a signal output device for connecting a digital signal processing device that should receive a signal, the conventional communication jack and the video output jack can be combined into one jack. is there.
[0009]
[Means for solving the problems]
The signal output device according to the present invention is:
A common jack (10) for connecting any one of analog signal processing equipment and digital signal processing equipment; and
An analog signal output from the analog signal output terminal of the main circuit (9), of the digital signal output from the digital signal output terminal of the main circuit (9), by selecting one of signals, the jack ( And signal selection means for sending to 10) .
The jack (10) comprises a first terminal J1 to which a digital signal input from a digital signal processing device is to be applied, and a second terminal J2 to which a signal selected by the signal selection means is to be applied, The first terminal J1 is connected to the digital signal input terminal of the main circuit ( 9 ) .
Or the main circuit (9) determines whether any device on the jack (10) is connected, when it is determined that any device is connected to the jack (10), there is some data inputted to the digital signal input terminal When there is no data input, the signal selection means is switched to select an analog signal, and when there is any data input, the signal selection means is switched to select a digital signal .
[0010]
The signal output device of the present invention, the analog signal processing device to the jack (10) is connected, after being detected that any device is connected by a main circuit (9), a jack (10) 1 It is determined whether there is any data input from the terminal J1 to the digital signal input terminal. Here, since an analog signal processing device is connected to the first terminal J1 of the jack (10) , it is determined that there is no data input. As a result, the signal selection means is switched to select an analog signal output from the analog signal output terminal of the main circuit ( 9 ) , and the analog signal is output from the second terminal J2 of the jack (10) to the analog signal processing circuit. Supplied to.
Further, when the digital signal processing device is connected to the jack (10), a main after the circuit some equipment by that (9) is detected to have been connected, the jack (10) the first digital signal from the terminal J1 input terminal of the It is determined whether there was any data input. Here, a digital signal processing device is connected to the first terminal J1 of the jack (10) , and the digital signal supplied from the digital signal processing device passes through the first terminal J1 and is digital in the main circuit ( 9 ) . Since it is input to the signal input terminal, it is determined that some data has been input. As a result, the signal selection means is switched to select the digital signal output from the digital signal output terminal of the main circuit ( 9 ) , and the digital signal is sent from the second terminal J2 of the jack (10) to the digital signal processing circuit. Supplied to.
[0011]
In a specific configuration, the jack (10) further includes a third terminal J3 that is grounded and a fourth terminal J4 that is pulled up when any device is connected to the jack (10). J4 is connected to the device detecting terminal JACK of the main circuit (9), the main circuit (9), the state of the signal detection terminal JACK, determines whether any device is connected to the jack (10).
[0013]
Specifically, the signal selection means is constituted by an analog switch (12).
As a result, a digital signal is input to one signal input terminal of the analog switch (12), and an analog signal is input to the other signal input terminal to switch the signal between the digital signal and the analog signal. I can do it.
[0014]
More specifically, the digital signal input terminal and the digital signal output terminal of the main circuit (9) are connected to one of the first terminal of the jack (10) and the analog switch (12) via the RS232C transceiver (4), respectively. A predetermined voltage boosted by the RS232C transceiver (4) is supplied to the analog switch (12) and is transmitted to the analog switch (12).
[0015]
According to the specific configuration, a predetermined voltage boosted by the RS232C transceiver (4) is supplied to the multiplexer (11) by using the RS232C transceiver (4) also provided in the conventional signal output device. Since the analog switch (12) can be operated, it is not necessary to provide a dedicated power supply circuit for the operation of the analog switch (12), and the circuit configuration is simplified.
[0016]
【The invention's effect】
According to the signal output device of the present invention, the conventional communication jack and the video output jack can be used as a single jack, so that the electronic device to be equipped with the signal output device can be downsized. I can do it.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention applied to a digital still camera will be specifically described below with reference to the drawings.
As shown in FIG. 1, the digital still camera according to the present invention has a communication / video output jack (10) to which a digital signal processing device such as a personal computer and an analog signal processing device such as a TV monitor can be connected. It has.
[0018]
The main circuit (9) of the digital still camera outputs an analog output terminal VIDEO to output a video signal, a digital signal input terminal RXD to which communication data such as a control signal is input, and communication data such as a control signal. A digital signal output terminal TXD to be output, a control signal output terminal CONT to output a control signal, and a device detection terminal JACK for detecting that any device is connected to the communication / video output jack (10). Is provided.
[0019]
An RS232C transceiver (4), a line driver (8), and a multiplexer (11) are interposed between the main circuit (9) and the communication / video output jack (10). The communication / video output jack (10) is a highly versatile 3-pin jack called a “stereo mini jack”. For example, when a personal computer is connected, control data supplied from the personal computer, etc. The first terminal J1 to which the communication data is applied, the second terminal J2 to which the communication data or video signal supplied from the output terminal of the analog switch (12) constituting the multiplexer (11) is applied, and grounded A third terminal J3 and a fourth terminal J4 that is pulled up when any device is connected to the jack (10) are provided.
[0020]
The first terminal J1 of the communication / video output jack (10) is connected to the digital signal input terminal RXD of the main circuit (9) via the inverter (6) of the RS232C transceiver (4). The second terminal J2 is connected to the common output terminal COM of the multiplexer (11). The fourth terminal J4 is connected to the device detection terminal JACK of the main circuit (9).
The digital signal output terminal TXD of the main circuit (9) is connected to the first input terminal CH1 of the multiplexer (11) via the inverter (7) of the RS232C transceiver (4). The video signal output terminal VIDEO of the main circuit (9) is connected to the second input terminal CH0 of the multiplexer (11) via the 75Ω line driver (8), the DC blocking capacitor C1, and the impedance matching resistor R1. Connected to.
[0021]
RS232C transceiver (4) comprises a power supply terminal _{V CC} of 3.3V supply is connected, by boosting the + 6V and -6V by the charge pump the voltage supplied to the power supply terminal (5), the voltage The data transfer operation is performed by the inverters (6) and (7). As a result, the communication data having an amplitude of 0 to 3.3 V obtained from the digital signal output terminal TXD of the main circuit (9) is boosted to an amplitude of -5.4 V to +5.4 V.
The RS232C transceiver (4) is connected to external capacitors C2 and C3, and outputs + 6V and -6V voltages obtained from the charge pump (5) from a pair of voltage output terminals V + and V-. It is possible.
[0022]
The communication data output from the digital signal output terminal TXD of the main circuit (9) is boosted to ± 5.4V through the RS232C transceiver (4) as described above, and then input to the first input terminal CH1 of the multiplexer (11). Is done.
On the other hand, the video signal output from the video signal output terminal VIDEO of the main circuit (9) passes through the 75Ω line driver (8), the DC blocking capacitor C1, and the impedance matching resistor R1, and the second of the multiplexer (11). Input to the input terminal CH0.
The magnitude of the impedance matching resistor R1 is set so that the total resistance value (R1 and R2) is 75Ω when the on-resistance inside the multiplexer (11) is R2.
[0023]
Further, a pair of power supply terminals _{V CC} and _{V EE} provided to a multiplexer (11), the voltage output terminal V + and the RS232C transceiver (4) V- are connected respectively, are input to the first input terminal CH1 The communication data of ± 5.4V or the video signal of ± 1V input to the second input terminal CH0 is covered by a voltage (± 6V) necessary for outputting from the common output terminal COM.
In order to pass ± 5.4V communication data and ± 1V video signal through the multiplexer (11), a negative power source capable of obtaining a voltage of -5.4V or less and a positive power source capable of obtaining a voltage of + 5.4V or more. power but is required use, since the current consumption of the multiplexer (11) is 1μA or less, a + 6V and -6V obtained from RS232C transceiver (4) as a positive power supply _{V CC} and the negative power source _{V EE} multiplexer (11) It can be done.
[0024]
The multiplexer (11) is switched by a control signal (CONT signal) obtained from the control signal output terminal CONT of the main circuit (9). That is, when the CONT signal is “H”, the multiplexer (11) is switched to the first input terminal CH1, and when the CONT signal is “L”, the multiplexer (11) is switched to the second input terminal CH0.
[0025]
FIG. 2 shows the switching operation of the multiplexer (11) by the main circuit (9).
After the power of the digital still camera is turned on, first, in step S1, the CONT signal from the main circuit (9) is set to “L”, and then the state of the device detection terminal JACK is detected, thereby communicating / video. It is determined whether any device is connected to the output jack (10). If it is determined NO, the process returns to step S1 to maintain the CONT signal at “L”.
[0026]
Thereafter, when it is determined as YES in step S2, it is determined whether or not there is any data input to the digital signal input terminal RXD of the main circuit (9). If there is no data input, the process proceeds to step S8. Thus, the TV monitor can be connected to the communication / video output jack (10) in a state where the video signal input to the second input terminal CH0 of the multiplexer (11) is selected. As a result, an image taken with a digital still camera can be displayed on the TV monitor.
[0027]
Thereafter, when the image monitoring is finished in step S9, the state of the device detection terminal JACK is detected again in step S10, and accordingly, no device is connected to the communication / video output jack (10) (No). If it is determined, the process returns to step S1 to maintain the CONT signal at "L".
If it is determined in step S10 that any device is connected to the communication / video output jack (10) (yes), the process returns to step S3 to the digital signal input terminal RXD of the main circuit (9). It is determined whether there is any data input.
[0028]
Here, when a personal computer is connected to the communication / video output jack (10), since the personal computer serves as a host and some control data is transmitted to the digital still camera, yes in step S3. It will be judged.
In step S4, the CONT signal is switched to “H”, and in step S5, communication data input to the first input terminal CH1 of the multiplexer (11) is selected and communication is performed from the main circuit (1). / Communication data can be supplied to the video output jack (10). As a result, bidirectional data communication is performed between the digital still camera and the personal computer.
[0029]
Thereafter, when communication with the personal computer is terminated in step S6, the state of the device detection terminal JACK is detected in step S7, and no device is connected to the communication / video output jack (10). If it is determined (No), the process returns to step S1 to switch the CONT signal to “L”. On the other hand, when it is determined that any device is connected to the communication / video output jack (10) (yes), the process returns to step S3, and the digital signal input terminal RXD of the main circuit (9) Determine whether there was data input.
[0030]
According to the above procedure, when an analog signal processing device such as a TV monitor is connected to the communication / video output jack (10), the video signal from the digital still camera is also used for communication / video output via the multiplexer (11). The signal is supplied to the jack (10), and signal processing in an analog signal processing device, for example, image display is possible.
On the other hand, when a digital signal processing device such as a personal computer is connected to the communication / video output jack (10), communication data from the digital still camera passes through the multiplexer (11) and the communication / video output jack (10). The data communication between the digital still camera and the digital signal processing device becomes possible.
[0031]
Even if a digital signal processing device such as a personal computer is connected to the communication / video output jack (10), even if the video signal is output from the video signal output terminal VIDEO of the digital still camera, the video signal is Since it only has an amplitude of ± 1 V and is sufficiently lower than the voltage of communication data ± 5.4 V, there is no possibility that the digital signal processing device will malfunction in response to this signal.
[0032]
In the above digital still camera, the communication jack (2) and the video output jack (3) provided in the conventional digital still camera are also used as one jack (10). The camera can be reduced in size by the amount of space.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a main part of a digital still camera according to the present invention.
FIG. 2 is a flowchart showing the operation of the digital still camera.
FIG. 3 is a circuit diagram showing a configuration of a conventional digital still camera.
(9) Main circuit
(4) RS232C transceiver
(5) Charge pump
(10) Communication / video output jack
(11) Multiplexer
(12) Analog switch

Claims (4)

For a main circuit having an analog signal output terminal , a digital signal output terminal, and a digital signal input terminal , an analog signal processing device that should receive an analog signal output from the main circuit, and a digital signal output from the main circuit A signal output device for connecting a digital signal processing device for receiving and transmitting a digital signal to a main circuit ,
A common jack (10) for connecting any one of analog signal processing equipment and digital signal processing equipment; and
An analog signal output from the analog signal output terminal of the main circuit (9), of the digital signal output from the digital signal output terminal of the main circuit (9), by selecting one of signals, the jack ( A signal selection means for sending to 10) ,
The jack (10) comprises a first terminal J1 to which a digital signal input from a digital signal processing device is to be applied, and a second terminal J2 to which a signal selected by the signal selection means is to be applied, The first terminal J1 is connected to the digital signal input terminal of the main circuit ( 9 ) ,
Or the main circuit (9) determines whether any device on the jack (10) is connected, when it is determined that any device is connected to the jack (10), there is some data inputted to the digital signal input terminal When there is no data input, the signal selection means is switched to select an analog signal, and when there is any data input, the signal selection means is switched to select a digital signal. A characteristic signal output device. The jack (10) further includes a third terminal J3 that is grounded and a fourth terminal J4 that is pulled up when any device is connected to the jack (10) . The fourth terminal J4 is a main circuit ( is connected to the device detecting terminal JACK 9), the main circuit (9), the state of the signal detection terminal JACK, the signal output according to claim 1 to determine whether any device is connected to the jack (10) apparatus.   The signal output device according to claim 1 or 2, wherein the signal selection means comprises an analog switch (12).   The digital signal input terminal and the digital signal output terminal of the main circuit (9) are connected to the first terminal of the jack (10) and one input terminal of the analog switch (12), respectively, via the RS232C transceiver (4). 4. The signal output device according to claim 3, wherein a predetermined voltage boosted by the RS232C transceiver (4) is supplied to the analog switch (12), and signal transmission is performed by the analog switch (12).

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