Computer system, camera module, and voltage control method

Abstract

The present invention prevents the occurrence of noise caused by crosstalk from exceeding the rating of a circuit connected to a communication data line. A computer system includes a first computer device and a second computer device that are connected by a first data line and a second data line for performing communication in a single-ended and full-duplex manner, wherein the first computer device is provided with a first intermediate voltage generation unit that changes a voltage of the first data line to a prescribed first intermediate voltage when the second computer device, having received transmission data transmitted from the first computer device to the second computer device through the first data line, transmits reception data to the first computer device through the second data line.

Description

Computer system, camera module and voltage control method

[0001] The present invention relates to a computer system, a camera module, and a voltage control method.

[0002] During single-ended digital communication, a phenomenon occurs in which noise due to crosstalk from a communication line that is communicating is superimposed on other signal lines that are not communicating.

[0003] In order to reduce such crosstalk, measures have been taken, such as using shielded communication cables or passing output signals through a low pass filter (LPF) to make them less susceptible to noise. Other proposals include circuit devices that suppress the crosstalk effect, as in Patent Document 1. However, these crosstalk countermeasure technologies do not take into consideration the relationship between the noise generated by crosstalk and the ratings of the circuits connected to the communication cables.

[0004] JP 8-274426 JP 2006-217305 JP 5-128410

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a technology that prevents the rated capacity of a circuit connected to a communication data line from being exceeded even if noise due to crosstalk occurs.

[0006] To solve the above problem, the present invention provides a computer system including a first computer device and a second computer device connected by a first data line and a second data line, which communicate in a single-ended and full-duplex manner, wherein the first computer device is provided with a first intermediate voltage generation unit that changes the voltage of the first data line from a predetermined basic voltage to a first intermediate voltage when the second computer device, which has received transmission data transmitted from the first computer device to the second computer device via the first data line, transmits received data to the first computer device via the second data line.

[0007] According to this, when received data is transmitted from the second computer device to the first computer device through the second data line, the voltage of the first data line is changed from a predetermined basic voltage to a first intermediate potential. Therefore, by setting the first intermediate voltage to a value that does not exceed the rating of the circuit connected to the first data line even if crosstalk occurs on the first data line, it is possible to prevent the rating of the circuit connected to the first data line from being exceeded even if crosstalk occurs on the first data line.

[0008] The present invention also provides a computer system including a first computer device and a second computer device connected by a first data line and a second data line, which communicate in a single-ended and full-duplex manner, wherein the second computer device has a second intermediate voltage generation unit that changes the voltage of the first data line from a predetermined basic voltage to a second intermediate voltage when the second computer device receives transmission data transmitted from the first computer device to the second computer device via the first data line and transmits received data to the first computer device via the second data line.

[0009] According to this, when received data is transmitted from the second computer device to the first computer device through the second data line, the voltage of the first data line is changed from a predetermined basic voltage to the second intermediate potential. Therefore, by setting the second intermediate voltage to a value that does not exceed the rating of the circuit connected to the first data line even if crosstalk occurs on the first data line, it is possible to prevent the rating of the circuit connected to the first data line from being exceeded even if crosstalk occurs on the first data line.

[0010] The present invention also provides a computer system including a first computer device and a second computer device connected by a first data line and a second data line, which communicate in a single-ended and full-duplex manner, wherein the first computer device is equipped with a third intermediate voltage generation unit that changes the voltage of the second data line from a predetermined basic voltage to a third intermediate voltage when transmitting data from the first computer device to the second computer device via the first data line.

[0011] According to this, when transmission data is transmitted from the first computer device to the second computer device through the first data line, the voltage of the second data line is changed from a predetermined basic voltage to the third intermediate potential. Therefore, by setting the third intermediate voltage to a value that does not exceed the rating of the circuit connected to the second data line even if crosstalk occurs on the second data line, it is possible to prevent the rating of the circuit connected to the second data line from being exceeded even if crosstalk occurs on the second data line.

[0012] The present invention also provides a computer system including a first computer device and a second computer device connected by a first data line and a second data line, which communicate in a single-ended and full-duplex manner, wherein the second computer device has a fourth intermediate voltage generation unit that changes the voltage of the second data line from a predetermined basic voltage to a fourth intermediate voltage when transmitting data from the first computer device to the second computer device via the first data line.

[0013] According to this, when transmission data is transmitted from the first computer device to the second computer device through the first data line, the voltage of the second data line is changed from a predetermined basic voltage to the fourth intermediate potential. Therefore, by setting the fourth intermediate voltage to a value that does not exceed the rating of the circuit connected to the second data line even if crosstalk occurs on the second data line, it is possible to prevent the rating of the circuit connected to the second data line from being exceeded even if crosstalk occurs on the second data line.

[0014] Also, in the present invention, the second computer device may be a module equipped with an imaging unit and an image processing unit, and may be configured to transmit the processing results in the image processing unit to the first computer device based on instructions transmitted from the first computer device to the second computer device.

[0015] The present invention also provides a camera module that is connected to a host computer device by first and second data lines that communicate in a single-ended, full-duplex manner, and that includes a camera and a control unit, wherein the camera module receives command data sent from the host computer device to the camera module via the first data line, and includes a fifth intermediate voltage generation unit that changes the voltage of the first data line from a predetermined basic voltage to a fifth intermediate voltage when the camera module sends response data to the host computer device via the second data line.

[0016] According to this, when the camera module receives command data sent from the host computer device to the camera module via the first data line and then sends response data to the host computer device via the second data line, the voltage of the first data line is changed from a predetermined basic voltage to the fifth intermediate voltage.Therefore, by setting the fifth intermediate voltage to a value that does not exceed the rating of the circuit connected to the first data line even if crosstalk occurs on the first data line, it is possible to prevent the rating of the circuit connected to the first data line from being exceeded even if crosstalk occurs on the first data line.

[0017] The present invention also provides a camera module that is connected to a host computer device by a first data line and a second data line that communicate in a single-ended, full-duplex manner, and that includes a camera and a control unit, and that includes a sixth intermediate voltage generation unit that changes the voltage of the second data line from a predetermined basic voltage to a sixth intermediate voltage when command data is sent from the host computer device to the camera module via the first data line.

[0018] According to this, when command data is sent from the host computer device to the camera module via the first data line, the voltage of the second data line is changed from a predetermined basic voltage to the sixth intermediate voltage. Therefore, by setting the sixth intermediate voltage to a value that does not exceed the rating of the circuit connected to the first data line even if crosstalk occurs on the first data line, it is possible to prevent the rating of the circuit connected to the first data line from being exceeded even if crosstalk occurs on the first data line.

[0019] The present invention also provides a voltage control method for controlling the voltage of a first data line of a first data line and a second data line that connect a first computer device and a second computer device and communicate in a single-ended, full-duplex manner, the method including the steps of: transmitting transmission data from the first computer device to the second computer device via the first data line; changing the voltage of the first data line from a predetermined base voltage to a seventh intermediate voltage; transmitting received data from the second computer device to the first computer device via the second data line; returning the voltage of the first data line from the seventh intermediate voltage to the base voltage; and receiving the received data by the first computer device via the second data line.

[0020] According to this, when received data is transmitted from the second computer device to the first computer device through the second data line, the voltage of the first data line is changed from a predetermined basic voltage to the seventh intermediate potential. Therefore, by setting the seventh intermediate voltage to a value that does not exceed the rating of the circuit connected to the first data line even if crosstalk occurs on the first data line, it is possible to prevent the rating of the circuit connected to the first data line from being exceeded even if crosstalk occurs on the first data line.

[0021] The present invention also provides a voltage control method for controlling the voltage of a second data line of a first data line and a second data line that connect a first computer device and a second computer device and communicate in a single-ended, full-duplex manner, the method including the steps of: changing the voltage of the second data line from a predetermined base voltage to an eighth intermediate voltage; transmitting transmission data from the first computer device to the second computer device through the first data line; receiving the transmission data by the second computer device; and returning the voltage of the second data line from the eighth intermediate voltage to the base voltage.

[0022] According to this, when received data is transmitted from the second computer device to the first computer device through the second data line, the voltage of the first data line is changed from a predetermined basic voltage to the eighth intermediate potential, and by setting the second intermediate voltage to a value that does not exceed the rating of the circuit connected to the first data line even if crosstalk occurs on the first data line, it is possible to prevent the rating of the circuit connected to the first data line from being exceeded even if crosstalk occurs on the first data line.

[0023] According to the present invention, even if noise occurs due to crosstalk, it is possible to prevent the rating of the circuit connected to the communication data line from being exceeded.

[0024] FIG. 1 is a block diagram showing an outline of the overall configuration of an image processing system according to a first embodiment of the present invention. FIG. 2 is a timing chart illustrating a method for controlling a circuit to prevent crosstalk according to the first embodiment of the present invention. FIG. 3 is a flowchart illustrating a method for controlling a circuit to prevent crosstalk according to the first embodiment of the present invention. FIG. 4 is a flowchart illustrating a method for controlling a circuit to prevent crosstalk according to a modified example of the first embodiment of the present invention. FIG. 5 is a block diagram showing an outline of the overall configuration of an image processing system according to a second embodiment of the present invention. FIG. 6 is a flowchart illustrating a method for controlling a circuit to prevent crosstalk according to the second embodiment of the present invention. FIG. 7 is a flowchart illustrating a method for controlling a circuit to prevent crosstalk according to a modified example of the second embodiment of the present invention.

[0025] [Application Examples] Application examples of the present invention will be described below with reference to the drawings.

[0026] 1 is a schematic diagram of the overall configuration of an image processing system 1 according to an application example. The image processing system 1 mainly includes a host device 100A, a camera module 200A, and a stabilized power supply 300. The camera module 200A and the host device 100A are connected by a communication line 400.

[0027] The camera module 200A includes a camera 220 and a microcomputer 230. The microcomputer 230 has a function of capturing an image by the camera 220 and executing predetermined processing on the captured image in response to a command received from the host device 100A via the communication line 400, and transmitting the processing result as a response to the host device 100A via the communication line 400.

[0028] The host device 100A is configured as a general computer device including a microcomputer 120. The host device 100A executes a predetermined application based on the processing results output from the above-described camera module 200A, for example.

[0029] The camera module 200A and the host device 100A communicate with each other via a communication line 400 using, for example, a universal asynchronous receiver / transmitter (UART) method.

[0030] The communication line 400 includes a transmission data line 420 connecting the Tx terminal of the host device 100A and the UART RX terminal of the camera module 200A, and a reception data line 410 connecting the Rx terminal of the host device 100A and the UART TX terminal of the camera module 200A.

[0031] The host device 100A has a Tx terminal, an Rx terminal, and a GND terminal. The GND terminal is connected to the GND terminal of the stabilized power supply 300. The Tx terminal is connected to an output port P11 of the microcomputer 120 via a connection line 131. The Rx terminal is connected to an input port P12 of the microcomputer 120. The connection line 131 connecting the Tx terminal and the microcomputer 120 is connected to the power supply 111 via a resistor 112 at a connection point 113. The connection point 113 is further connected to GND 116 via a resistor 114 and a switching element 115 connected in series. In addition, the control terminal of the switching element 115 is connected to an I / O port of the microcomputer 120 via a connection line 132. A connection point 117 on the connection line 132 is connected to GND 116 via a resistor 118. Here, the intermediate voltage generating circuit 110 includes a connection point 113 , a resistor 112 , a power supply 111 , a resistor 114 , a switching element 115 , a GND 116 , a connection line 132 , a connection point 117 , and a resistor 118 .

[0032] The UART RX terminal of the camera module 200A is connected to the input port P22 of the microcomputer 230 via a connection line 252, and the UART TX terminal is connected to the output port P21 of the microcomputer 120 via a connection line 251.

[0033] The stabilized power supply 200 outputs a constant voltage of 5 V from a PW terminal and also has a GND terminal.

[0034] 2 and 3, a crosstalk countermeasure circuit control method in an image processing system 1 according to an application example will be described. In the timing chart of Fig. 2, along the time axis progressing to the right in the drawing, the upper row shows the voltage of the receiving data line 410, and the lower row shows the voltage of the transmitting data line 420.

[0035] First, host device 100A generates command data and transmits it from the Tx terminal to the UART TX terminal of camera module 200A via transmission data line 420 (step S101). When host device 100A transmits command data, an L (low) control signal is input from the I / O port of microcomputer 120 to the control terminal of switching element 115. Since switching element 115 is turned off, the voltage of transmission data line 420 connected to the Tx terminal is controlled by power supply 111, resistor 112, and output signal generation circuit 121 of output port P11 of microcomputer 120. In this state, for example, the H (high) voltage appearing at the Tx terminal is 3.3 V.

[0036] The UART R terminal of the camera module 200A receives command data through the transmission data line 420 (step S201).

[0037] When the host device 100A transmits command data (T1 in FIG. 2), it lowers the voltage on the transmission data line 420 (step S102). Specifically, when the command data is transmitted, the control signal output from the I / O port of the microcomputer 120 is switched from L to H. This turns on the switching element 115, so that the voltage on the transmission data line 420 is controlled to a voltage (intermediate voltage) obtained by dividing the voltage of the power supply 111 in accordance with the ratio of the resistance values ​​of the resistors 112 and 114 connected in series. The intermediate voltage can be set to, for example, 2.5 V.

[0038] Upon receiving the command data, camera module 200A generates response data in accordance with the command data and transmits the response data from the UART TX terminal to the Rx terminal of host device 100A via reception data line 410 (step S202). At this time, as shown in Fig. 2, since the voltage of transmission data line 420 is set to an intermediate voltage, even if crosstalk occurs on transmission data line 420 due to the transmission of response data via reception data line 410, the voltage on transmission data line 420 is kept low, and it is possible to prevent the rated voltage of the circuit connected to transmission data line 420 from being exceeded.

[0039] The host device 100A receives the response data at its Rx terminal via the receive data line 410 (step S103).

[0040] When the host device 100A has completed receiving the response data (T2 in FIG. 2), the control signal output from the I / O port of the microcomputer 120 is switched from H to L, thereby returning the voltage on the transmission data line 420 to its original level (step 104).

[0041] [Embodiment 1] Hereinafter, with reference to the drawings (including the drawings already described in the application examples), a detailed description of the embodiments of the present invention will be given. However, unless otherwise specified, the specific configurations described in the embodiments are not intended to limit the scope of the present invention to those specific configurations.

[0042] 1 is a schematic diagram of the overall configuration of an image processing system 1 according to a first embodiment. The image processing system 1 is mainly configured to include a host device 100A, a camera module 200A, and a stabilized power supply 300. The camera module 200A and the host device 100A are communicatively connected via a communication line 400. Here, the host device 100A corresponds to the first computer device of the present invention, the camera module 200A corresponds to the second computer device and module of the present invention, and the image processing system 1 corresponds to the computer system of the present invention.

[0043] The camera module 200A includes a camera 220 and a microcomputer 230. The camera 220 and the microcomputer 230 can be connected, for example, by a flexible cable 240, but the configuration of the camera module 200A is not limited to this. The microcomputer 230 has a function of capturing images using the camera 220 and performing predetermined processing on the captured images in response to commands received from the host device 100A via a communication line 400, and transmitting the processing results as a response to the host device 100A via the communication line 400. Examples of image processing by the microcomputer 230 include, but are not limited to, detection of a human body, face, or hand in an image; age estimation, gender estimation, facial expression estimation, facial direction estimation, gaze estimation, and blink estimation performed by analyzing facial information detected in the image; and matching (face recognition) of a person in an image against features registered in advance in a memory. Here, the camera 220 corresponds to the camera and imaging unit of the present invention, and the microcomputer 230 corresponds to the control unit and image processing unit of the present invention.

[0044] The host device 100A is configured as a general computer device including a microcomputer 120. That is, it is a computer device having a processor such as a CPU, a main memory device such as a RAM or a ROM, and an auxiliary memory device. The host device 100A executes a predetermined application based on the processing results output from the above-mentioned camera module 200A, for example.

[0045] The camera module 200A and the host device 100A communicate with each other using, for example, the UART (Universal Asynchronous Receiver / Transmitter) method via the communication line 400. The UART method is an asynchronous, full-duplex, single-ended data communication method.

[0046] The communication line 400 includes a transmission data line 420 that connects the Tx terminal of the host device 100A and the UART RX terminal of the camera module 200A, and a reception data line 410 that connects the Rx terminal of the host device 100A and the UART TX terminal of the camera module 200A. Here, the transmission data line 420 and the reception data line 410 correspond to the first data line and the second data line of the present invention, respectively.

[0047] The host device 100A has a Tx terminal, an Rx terminal, and a GND terminal. The GND terminal is connected to the GND terminal of the stabilized power supply 300. The Tx terminal is connected to an output port P11 of the microcomputer 120 via a connection line 131. The Rx terminal is connected to an input port P12 of the microcomputer 120, but a detailed description thereof will be omitted here. The connection line 131 connecting the Tx terminal and the microcomputer 120 is connected to the power supply 111 via a resistor 112 at a connection point 113. The connection point 113 is further connected to GND 116 via a resistor 114 and a switching element 115 connected in series. The control terminal of the switching element 115 is connected to an I / O port of the microcomputer 120 via a connection line 132. A connection point 117 on the connection line 132 is connected to GND 116 via a resistor 118. Here, the intermediate voltage generation circuit 110 includes a connection point 113, a resistor 112, a power supply 111, a resistor 114, a switching element 115, a GND 116, a connection line 132, a connection point 117, and a resistor 118. The switching element 115 may be, for example, an N-type transistor, but is not limited to this. Here, the intermediate voltage generation circuit 110 corresponds to a first intermediate voltage generation unit of the present invention.

[0048] The camera module 200A includes a UART connector 250 having a UART TX terminal, a UART RX terminal, a GND terminal, and a power supply input terminal PW. The UART RX terminal is connected to an input port P22 of the microcomputer 230 via a connection line 252. The UART TX terminal is connected to an output port P21 of the microcomputer 120 via a connection line 251.

[0049] The stabilized power supply 200 outputs a constant voltage of 5 V from a PW terminal and also has a GND terminal.

[0050] 2 and 3 are timing charts and sequence diagrams illustrating a crosstalk countermeasure circuit control method in the image processing system 1. This crosstalk countermeasure circuit control method corresponds to the voltage control method of the present invention. In FIG. 2, along the time axis progressing to the right, the upper part shows the voltages appearing at the Rx terminal of the host device 100A and the UART TX terminal of the camera module 200A, i.e., the voltage of the receive data line 410. The lower part of FIG. 2 shows the voltages appearing at the Tx terminal of the host device 100A and the UART RX terminal of the camera module 200A, i.e., the voltage of the transmit data line 420.

[0051] First, the host device 100A generates command data and transmits it from the Tx terminal to the UART TX terminal of the camera module 200A via the transmission data line 420 (step S101). When transmitting command data in the host device 100A, an L (low) control signal is input from the I / O port of the microcomputer 120 to the control terminal of the switching element 115. Since the switching element 115 is turned off, the voltage of the transmission data line 420 connected to the Tx terminal is controlled by the power supply 111, the resistor 112, and the output signal generating circuit 121 of the output port P11 of the microcomputer 120. In this state, for example, the H (high) voltage appearing at the Tx terminal is 3.3 V. This voltage is referred to as the base voltage, and may be H as described herein or L (0 V). Here, the predetermined basic voltages are exemplified as 3.3 V for the H voltage and 0 V for the L voltage, but these values ​​can be set appropriately depending on the system configuration, communication specifications, etc., and are not limited to the values ​​exemplified.

[0052] The UART R terminal of the camera module 200A receives command data through the transmission data line 420 (step S201). Here, the command data corresponds to the transmission data and instructions of the present invention.

[0053] When the host device 100A transmits command data (T1 in FIG. 2), it lowers the voltage on the transmission data line 420 (step S102). Specifically, when the command data is transmitted, the control signal output from the I / O port of the microcomputer 120 is switched from L to H. This turns on the switching element 115, so that the voltage on the transmission data line 420 is controlled to a voltage (intermediate voltage) obtained by dividing the voltage of the power supply 111 in accordance with the ratio of the resistance values ​​of the resistors 112 and 114 connected in series. The intermediate voltage can be set to, for example, 2.5 V. Here, the intermediate voltage corresponds to the first intermediate voltage and the seventh intermediate voltage of the present invention.

[0054] Upon receiving the command data, camera module 200A generates response data in accordance with the command data and transmits the response data from the UART TX terminal to the Rx terminal of host device 100A via reception data line 410 (step S202). At this time, as shown in FIG. 2, since the voltage of transmission data line 420 is set to an intermediate voltage, even if crosstalk occurs on transmission data line 420 due to the transmission of response data via reception data line 410, the voltage on transmission data line 420 is kept low, thereby preventing the voltage from exceeding the rated voltage of the circuit connected to transmission data line 420. Here, the response data corresponds to the reception data and processing result of the present invention.

[0055] The host device 100A receives the response data at its Rx terminal via the receive data line 410 (step S103).

[0056] When the host device 100A has completed receiving the response data (T2 in FIG. 2), it returns the voltage of the transmission data line 420 to its original state (step 104). Specifically, when the reception of the response data has completed, the control signal output from the I / O port of the microcomputer 120 is switched from H to L. This turns off the switching element 115, so that the voltage of the transmission data line 420 is controlled by the power supply 111, the resistor 112, and the output signal generation circuit 121 of the microcomputer 120 to the voltage of the connection line 131 connected to the Tx terminal.

[0057] [Modification] In the first embodiment, the voltage of the transmission data line 420 connected to the Tx terminal of the host device 100A is changed to an intermediate voltage. However, an intermediate voltage generation circuit may be provided between the Rx terminal and the input port P12 of the microcomputer 120 to change the voltage of the reception data line 410 connected to the Rx terminal of the host device 100A to an intermediate voltage. By changing the voltage of the reception data line 410 to an intermediate voltage when command data is transmitted through the transmission data line 420, even if crosstalk occurs on the reception data line 410, the voltage of the reception data line 410 can be kept low and prevented from exceeding the rated voltage of the circuit connected to the reception data line 410. The intermediate voltage generation circuit may be provided on both or either the Tx terminal side and the Rx terminal side of the host device 100A. Here, this intermediate voltage corresponds to the third intermediate voltage and the eighth intermediate voltage of the present invention, and the intermediate voltage generation circuit corresponds to the third intermediate voltage generation unit of the present invention.

[0058] 4 is a sequence diagram illustrating a method for controlling a circuit to prevent crosstalk in this case. Processes common to those in FIG. 3 are assigned common reference numerals and detailed descriptions thereof will be omitted. This method for controlling a circuit to prevent crosstalk corresponds to the voltage control method of the present invention.

[0059] First, the host device 100A lowers the voltage on the receive data line 410 to an intermediate voltage (step S111). Next, command data is transmitted from the Tx terminal of the host device 100A via the transmit data line 420 to the UART TX terminal of the camera module 200A (step S101). The UART R terminal of the camera module 200A receives the command data via the transmit data line 420 (step S201). Next, the host device 100A restores the voltage on the receive data line 410 (step S112). The camera module 200A transmits response data from the UART TX terminal to the Rx terminal of the host device 100A via the receive data line 410 (step S202). The Rx terminal of the host device 100A receives the response data via the receive data line 410 (step S103).

[0060] Furthermore, in the first embodiment, an intermediate voltage generation circuit is provided that reduces the voltage to an intermediate voltage when the voltage of the transmission data line 420 connecting the host device 100A and the camera module 200A is H. However, an intermediate voltage generation circuit with a similar configuration may be provided that increases the voltage to an intermediate voltage when the voltage of the transmission data line 420 connecting the host device 100A and the camera module 200A is L. This prevents the rated voltage of the circuit connected to the transmission data line 420 from exceeding even if a negative voltage change occurs on the transmission data line 420 due to crosstalk. In this case, as in the above-described modification, an intermediate voltage generation circuit with a similar configuration that increases the voltage to an intermediate voltage when the voltage of the transmission data line 420 connecting the host device 100A and the camera module 200A is L may be provided. Such intermediate voltages correspond to the first intermediate voltage and the third intermediate voltage of the present invention, and the intermediate voltage generation circuits correspond to the first intermediate voltage generation unit and the third intermediate voltage generation unit of the present invention, respectively. Furthermore, these intermediate voltages correspond to the seventh intermediate voltage and the eighth intermediate voltage.

[0061] 5 is a schematic diagram of the overall configuration of an image processing system 2 according to Example 2. Components common to the image processing system 1 according to Example 1 are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0062] The image processing system 2 according to the second embodiment is primarily configured to include a host device 100B, a camera module 200B, and a stabilized power supply 300. In the image processing system 2, an intermediate voltage generation circuit 210 is provided in the camera module 200B. Here, the host device 100B corresponds to the first computer device and host computer device of the present invention, the camera module 200B corresponds to the second computer device and camera module of the present invention, and the image processing system 2 corresponds to the computer system of the present invention. The UART TX terminal of the camera module 200B is connected to an output port P21 of the microcomputer 230 via a connection line 251. An output signal generation circuit is connected to the output port P21 of the microcomputer 230, but details will be omitted here. The UART RX terminal of the camera module 200B is connected to an input port P22 of the microcomputer 230 via a connection line 251, but details will be omitted here. A connection line 251 connecting the UART TX terminal and the microcomputer 230 is connected at a connection point 213 to a power supply 211 via a resistor 212. The connection point 213 is further connected to a GND 216 via a resistor 214 and a switching element 215 connected in series. A control terminal of the switching element 215 is connected to an I / O port of the microcomputer 230 via a connection line 252. A connection point 217 on the connection line 252 is connected to the GND 216 via a resistor 218. When receiving command data in the camera module 200B, an L (low) control signal is input from the I / O port of the microcomputer 230 to the control terminal of the switching element 215, turning the switching element 215 off. In this state, for example, the H (high) voltage appearing at the UART RX terminal is 3.3 V. This base voltage may be H as described here, or L (0 V). However, these values ​​are merely examples and can be set appropriately depending on the system configuration, communication specifications, etc., and are not limited to the illustrated values. Here, intermediate voltage generation circuit 210 includes connection point 213, resistor 212, power supply 2111, resistor 214, switching element 215, GND 216, connection line 252, connection point 217, and resistor 218. Here, intermediate voltage generation circuit 210 corresponds to the second intermediate voltage generation unit and fifth intermediate voltage generation unit of the present invention.

[0063] 6 is a sequence diagram illustrating a method for controlling a circuit to prevent crosstalk in the image processing system 2. The timing chart of the method for controlling a circuit to prevent crosstalk according to this embodiment is the same as that of FIG. 2 (however, T1 and T2 are replaced with T3 and T4). This method for controlling a circuit to prevent crosstalk corresponds to the voltage control method of the present invention.

[0064] First, the host device 100B generates command data and transmits the command data from the Tx terminal to the UART TX terminal of the camera module 200B via the transmission data line 420 (step S101).

[0065] The UART R terminal of the camera module 200B receives command data via the transmission data line 420 (step S201).

[0066] When the camera module 200B receives the command data (T3 in FIG. 2), it lowers the voltage on the transmission data line 420 (step S211). Specifically, when the command data is transmitted, the control signal output from the I / O port of the microcomputer 230 is switched from L to H. This turns on the switching element 215, so that the voltage on the transmission data line 420 is controlled to a voltage (intermediate voltage) obtained by dividing the voltage of the power supply 211 in accordance with the ratio of the resistance values ​​of the resistors 212 and 214 connected in series. The intermediate voltage can be set to, for example, 2.5 V. Here, this intermediate voltage corresponds to the second intermediate voltage and the fifth intermediate voltage of the present invention.

[0067] Upon receiving the command data, camera module 200B generates response data in accordance with the command data and transmits the response data from the UART TX terminal to the Rx terminal of host device 100B via reception data line 410 (step S202). At this time, as shown in Fig. 2, since the voltage of transmission data line 420 is set to an intermediate voltage, even if crosstalk occurs on transmission data line 420 due to the transmission of response data through transmission data line 420, the voltage on transmission data line 420 is kept low, and it is possible to prevent the rated voltage of the circuit connected to transmission data line 420 from being exceeded.

[0068] The host device 100B receives the response data at its Rx terminal via the receive data line 410 (step S103).

[0069] When the host device 100B has completed receiving the response data (T2 in FIG. 2), the voltage on the transmission data line 420 is restored (step S212). Specifically, when the reception of the response data is completed, the control signal output from the I / O port of the microcomputer 230 is switched from H to L. This turns off the switching element 215, so that the voltage on the transmission data line 420 is controlled to the voltage on the connection line 251 connected to the Tx terminal by the power supply 211, resistor 212, and the output signal generation circuit of the microcomputer 230. Here, the voltage on the transmission data line 420 may be restored after the response data is transmitted from the camera module 200B to the host device 100B.

[0070] In the second embodiment, the case where the voltage of the transmission data line 420 connected to the UART RX terminal of the camera module 200B is changed to an intermediate voltage has been described. However, an intermediate voltage generation circuit may be provided between the UART RX terminal and the output port P21 of the microcomputer 230 so as to change the voltage of the reception data line 410 connected to the UART TX terminal of the camera module 200B to an intermediate voltage. By changing the voltage of the reception data line 410 to an intermediate voltage when command data is transmitted through the reception data line 410, even if crosstalk occurs on the reception data line 410, the voltage of the reception data line 410 can be kept low and prevented from exceeding the rated voltage of the circuit connected to the reception data line 410. Here, these intermediate voltages correspond to the fourth intermediate voltage, sixth intermediate voltage, and eighth intermediate voltage of the present invention, and the intermediate voltage generation circuit corresponds to the fourth intermediate voltage generation unit and sixth intermediate voltage generation unit of the present invention.

[0071] 7 is a sequence diagram illustrating a method for controlling a crosstalk countermeasure circuit in this case. Processes common to those in FIG. 6 are assigned common reference numerals and detailed descriptions thereof will be omitted. This method for controlling a crosstalk countermeasure circuit corresponds to the voltage control method of the present invention.

[0072] First, the camera module 200B lowers the voltage of the reception data line 410 to an intermediate voltage (step S221). Next, command data is transmitted from the Tx terminal of the host device 100B via the transmission data line 420 to the UART TX terminal of the camera module 200A (step S101). The UART R terminal of the camera module 200B receives the command data via the transmission data line 420 (step S201). Next, the camera module 200B restores the voltage of the reception data line 410 (step S222). Then, the camera module 200B transmits response data from the UART TX terminal to the Rx terminal of the host device 100B via the reception data line 410 (step S202). The Rx terminal of the host device 100B receives the response data via the reception data line 410 (step S103).

[0073] The intermediate voltage generating circuit may be provided on either or both of the UART RX terminal side and the UART TX terminal side of the camera module 200B.

[0074] Furthermore, in the second embodiment, an intermediate voltage generation circuit 210 is provided that reduces the voltage to an intermediate voltage when the voltage of the transmission data line 420 connecting the host device 100B and the camera module 200B is H. However, an intermediate voltage generation circuit with a similar configuration may be provided that increases the voltage to an intermediate voltage when the voltage of the transmission data line 420 connecting the host device 100B and the camera module 200B is L. This prevents the voltage of the transmission data line 420 from exceeding the rated voltage of the circuit connected to the transmission data line 420 even if a negative voltage change occurs on the transmission data line 420 due to crosstalk. In this case, as in the above-described modification, an intermediate voltage generation circuit with a similar configuration that increases the voltage to an intermediate voltage when the voltage of the reception data line 410 connecting the host device 100B and the camera module 200B is L may be provided. These intermediate voltages correspond to the second, fourth, fifth, and sixth intermediate voltages of the present invention, and the intermediate voltage generating circuits correspond to the second, fourth, fifth, and sixth intermediate voltage generating units of the present invention, respectively. Also, these intermediate voltages correspond to the seventh and eighth intermediate voltages of the present invention.

[0075] In the following, the components of the present disclosure will be described with the reference numerals in the drawings to enable comparison between the components of the present disclosure and the configurations of the embodiments. <Supplementary Note 1> A computer system (1) including a first computer device (100A) and a second computer device (200A) connected by a first data line (420) and a second data line (410) for single-ended and full-duplex communication, wherein the first computer device (100A) includes a first intermediate voltage generator (110) that changes the voltage of the first data line (420) from a predetermined base voltage to a first intermediate voltage when the second computer device (200A) receives transmission data transmitted from the first computer device (100A) to the second computer device (200A) via the first data line (420) and transmits received data to the first computer device (100A) via the second data line (410). <Supplementary Note 2> A computer system (2) including a first computer device (100B) and a second computer device (200B) connected by a first data line (420) and a second data line (410) for single-ended and full-duplex communication, wherein the second computer device (200B) is characterized in that the second computer device (200B) has a second intermediate voltage generation unit (210) that changes the voltage of the first data line (420) from a predetermined base voltage to a second intermediate voltage when the second computer device (200B) receives transmission data transmitted from the first computer device (100B) to the second computer device (200B) via the first data line (420) and transmits received data to the first computer device (100B) via the second data line (410).<Supplementary Note 3> A computer system (1) including a first computer device (100A) and a second computer device (200A) connected by a first data line (420) and a second data line (410) for single-ended and full-duplex communication, wherein the first computer device (100A) is provided with a third intermediate voltage generation unit that changes the voltage of the second data line (410) from a predetermined base voltage to a third intermediate voltage when transmitting transmission data from the first computer device (100A) to the second computer device (200A) via the first data line (420). <Supplementary Note 4> A computer system (2) including a first computer device (100B) and a second computer device (200B) connected by a first data line (420) and a second data line (410) for single-ended and full-duplex communication, wherein the second computer device (200B) is provided with a fourth intermediate voltage generation unit that changes the voltage of the second data line (410) from a predetermined base voltage to a fourth intermediate voltage when transmitting transmission data from the first computer device (100B) to the second computer device (200B) via the first data line (420). <Supplementary Note 5> The computer system (1, 2) according to any one of Supplementary Notes 1 to 4, wherein the second computer device (200A, 200B) is a module including an imaging unit (220) and an image processing unit (230), and transmits a processing result in the image processing unit (230) to the first computer device (100A, 100B) based on an instruction transmitted from the first computer device (100A, 100B) to the second computer device (200A, 200B).<Supplementary Note 6> A camera module (200B) that is connected to a host computer device (100B) by a first data line (420) and a second data line (410) that communicate in a single-ended and full-duplex manner, and that includes a camera (220) and a control unit (230), wherein the camera module (200B) receives command data transmitted from the host computer device (100B) to the camera module (200B) via the first data line (420), and the camera module (200B) includes a fifth intermediate voltage generation unit (110) that changes the voltage of the first data line (410) from a predetermined basic voltage to a fifth intermediate voltage when transmitting response data to the host computer device (100B) via the second data line (410). <Supplementary Note 7> A camera module (200B) that is connected to a host computer device (100B) by a first data line (420) and a second data line (410) that communicate in a single-ended and full-duplex manner, and that includes a camera (220) and a control unit (240), characterized in that the camera module further includes a sixth intermediate voltage generation unit that changes the voltage of the second data line (410) from a predetermined basic voltage to a sixth intermediate voltage when command data is transmitted from the host computer device (100B) to the camera module (200B) via the first data line (420).<Supplementary Note 8> A voltage control method for controlling a voltage of a first data line (420) of a first data line (420) and a second data line (410) that connect a first computer device (100A, 100B) and a second computer device (200A, 200B) and communicate in a single-ended and full-duplex manner, the method comprising the steps of: transmitting transmission data from the first computer device (100A, 100B) to the second computer device (200A, 200B) through the first data line (420); changing the voltage of the first data line (420) from a predetermined base voltage to a seventh intermediate voltage; transmitting received data from the second computer device (200A, 200B) to the first computer device (100A, 100B) through the second data line (410); and returning the voltage of the first data line (420) from the seventh intermediate voltage to the base voltage. the first computer device (100A, 100B) receiving the received data through the second data line (410). <Supplementary Note 9> A voltage control method for controlling the voltage of the second data line (410) of a first data line (420) and a second data line (410) that connect a first computer device (100A, 100B) and a second computer device (200A, 200B) and communicate in a single-ended and full-duplex manner, comprising the steps of: changing the voltage of the second data line (410) from a predetermined base voltage to an eighth intermediate voltage; transmitting transmission data from the first computer device (100A, 100B) to the second computer device (200A, 200B) through the first data line (420); receiving the transmission data by the second computer device (200A, 200B); and returning the voltage of the second data line (410) from the eighth intermediate voltage to the base voltage.

[0076] 1, 2 Image processing system 100A, 100B Host computer device 110 Intermediate voltage generating unit 200A, 200B Camera module 410 Receiving data line 420 Transmitting data line

Claims

1. A computer system including a first computer device and a second computer device connected by a first data line and a second data line for single-ended, full-duplex communication, wherein the first computer device is characterized in that the second computer device receives transmission data transmitted from the first computer device to the second computer device via the first data line and changes the voltage of the first data line from a predetermined base voltage to a first intermediate voltage when transmitting received data to the first computer device via the second data line.

2. A computer system including a first computer device and a second computer device connected by a first data line and a second data line, which communicate in a single-ended and full-duplex manner, wherein the second computer device is characterized in that the second computer device receives transmission data transmitted from the first computer device to the second computer device via the first data line and has a second intermediate voltage generation unit that changes the voltage of the first data line from a predetermined basic voltage to a second intermediate voltage when transmitting received data to the first computer device via the second data line.

3. A computer system including a first computer device and a second computer device connected by a first data line and a second data line, which communicate in a single-ended and full-duplex manner, wherein the first computer device is equipped with a third intermediate voltage generation unit that changes the voltage of the second data line from a predetermined basic voltage to a third intermediate voltage when transmitting data from the first computer device to the second computer device through the first data line.

4. A computer system including a first computer device and a second computer device connected by a first data line and a second data line, which communicate in a single-ended and full-duplex manner, wherein the second computer device is equipped with a fourth intermediate voltage generation unit that changes the voltage of the second data line from a predetermined basic voltage to a fourth intermediate voltage when transmitting data from the first computer device to the second computer device via the first data line.

5. A computer system according to any one of claims 1 to 4, characterized in that the second computer device is a module equipped with an imaging unit and an image processing unit, and transmits the processing results of the image processing unit to the first computer device based on instructions transmitted from the first computer device to the second computer device.

6. A camera module comprising a camera and a control unit, connected to a host computer device by first and second data lines for single-ended and full-duplex communication, wherein the camera module receives command data sent from the host computer device to the camera module via the first data line, and comprises a fifth intermediate voltage generation unit that changes the voltage of the first data line from a predetermined basic voltage to a fifth intermediate voltage when sending response data to the host computer device via the second data line.

7. A camera module comprising a camera and a control unit, connected to a host computer device by first and second data lines for single-ended and full-duplex communication, characterized in that it also comprises a sixth intermediate voltage generation unit that changes the voltage of the second data line from a predetermined basic voltage to a sixth intermediate voltage when command data is sent from the host computer device to the camera module via the first data line.

8. A voltage control method for controlling the voltage of a first data line of a first data line and a second data line that connect a first computer device and a second computer device and communicate in a single-ended, full-duplex manner, comprising the steps of: transmitting transmission data from the first computer device to the second computer device via the first data line; changing the voltage of the first data line from a predetermined base voltage to a seventh intermediate voltage; transmitting received data from the second computer device to the first computer device via the second data line; returning the voltage of the first data line from the seventh intermediate voltage to the base voltage; and receiving the received data by the first computer device via the second data line.

9. A voltage control method for controlling the voltage of the second data line of a first data line and a second data line that connect a first computer device and a second computer device and communicate in a single-ended, full-duplex manner, comprising the steps of: changing the voltage of the second data line from a predetermined base voltage to an eighth intermediate voltage; transmitting transmission data from the first computer device to the second computer device through the first data line; receiving the transmission data by the second computer device; and returning the voltage of the second data line from the eighth intermediate voltage to the base voltage.

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