JP2008304794A - Electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic apparatus for storing analog EDID data and digital EDID data and which is capable of preventing the influence of abnormal voltage fluctuations occurring in a connector receiving a signal from the outside. <P>SOLUTION: A CPU 13 sets an operation mode of a reproduction part to a mode, corresponding to an image signal (an analog image signal or a digital image signal), outputted from a source apparatus 150 between a first mode and a second mode by controlling the reproduction part 10, based on data (reproduction specification information) outputted from a storage part 34. When the operating mode of the reproduction part 10, corresponding to the image signal outputted from the source apparatus 150, is the first mode, the CPU 13 controls a switching circuit 33 so that a terminal T1 is connected to a terminal T2 (voltage node N), while the operating mode of the reproduction part 10 is set to the first mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic device, and more particularly to an electronic device that can handle different types of video signals by switching a plurality of specification information stored in advance.

  As a standard for transmitting a digital video (or audio) signal, for example, a DVI (Digital visual Interface) standard is used. In recent years, the HDMI (High Definition Multimedia Interface) standard, which is an improvement of the DVI standard, is being adopted.

  When a video signal is transmitted and received between two electronic devices conforming to the HDMI standard, a transmission device for the signal acquires data called EDID (Extended Display Identification) from the reception device. Thereby, the transmission device can output the video signal in a form according to the reception specification of the reception device. The information included in the EDID data includes, for example, information indicating the specifications / characteristics (resolution, aspect ratio, full HD (High Definition) compatible, etc.) of the electronic device on the receiving side.

  Techniques relating to electronic device control using EDID data are disclosed in, for example, the following documents. A display monitor input channel switching control device described in Japanese Patent Laid-Open No. 2003-29729 (Patent Document 1) determines whether a video signal input from a computer is a signal compliant with an analog specification or a digital specification. Based on the determination result, the EDID data, the input channel, and the OSD (On Screen Display) are switched according to the specifications of the video signal. As a result, it is possible to avoid a problem (for example, a problem that nothing is displayed on the screen) due to a mismatch between the specification of the output signal of the computer and the input channel of the display monitor.

  A display device described in Japanese Patent Laying-Open No. 2005-91955 (patent document 2) includes a storage unit that stores display-specific specification information for each display signal interface format, a determination unit that determines a display signal interface format, and a storage unit. Output means for selecting specification information corresponding to the determination signal generated by the determination means from the specification information stored in the means and outputting the information from the storage means. The specification information is selected based on only the determination signal in a state where the storage means, the determination means, and the output means are all operable. As a result, this display device can realize a DDC (Display Data Channel) function.

An electronic device described in Japanese Patent Application Laid-Open No. 2006-179973 (Patent Document 3) stores EDID data indicating a plurality of types of reception specifications in a memory unit, and sets its own specification from the memory unit when the reception specification is set. Is extracted and stored in the HDMI transmission / reception unit. Further, the electronic device described above outputs EDID data in the HDMI transmission / reception unit in response to an external EDID data acquisition request. This eliminates the need to store separate EDID data for each of a plurality of types of reception specifications, thereby facilitating manufacturing work and shipping work.
JP 2003-29729 A Japanese Patent Laid-Open No. 2005-91795 JP 2006-179973 A

  An electronic device that conforms to the HDMI standard and can receive a digital video signal and an analog video signal (hereinafter referred to as a receiving device) receives, for example, EDID data indicating reception specifications of the analog video signal and a digital video signal. EDID data indicating the specification is stored therein. Some of such receiving apparatuses set their reproduction specifications based on the EDID data. As a result, the receiving apparatus can cope with the video signal from the transmitting apparatus.

  Generally, an acquisition request for EDID data from a transmission device to a reception device is transmitted via a cable. The receiving device is provided with a connector connected to the cable and having a plurality of terminals. Based on the voltage level of the terminal corresponding to the acquisition request among the plurality of terminals, the receiving apparatus determines EDID data to be output to the transmitting apparatus.

  However, when the cable is disconnected from the connector or when the connection between the connector and the cable is insufficient, the voltage level of the terminal may vary. In this case, the following problems may occur.

  The receiving apparatus outputs the EDID data corresponding to the digital video signal even though the EDID data corresponding to the analog video signal is once output. This means that the reproduction specification of the receiving device is changed. As a result, when the cable is reconnected to the connector and an analog video signal is sent from the transmission device, there is a possibility that the reproduction processing at the reception device is not properly performed.

  Therefore, an object of the present invention is to store analog specification EDID data and digital specification EDID data, and to avoid the influence of the voltage change even if an unusual voltage change occurs in a connector receiving an external signal. It is to provide possible electronic devices.

  In summary, the present invention is capable of reproducing an analog video signal and a digital video signal, and playing specification information corresponding to one video signal from an external device that outputs one video signal of the analog video signal and the digital video signal. This is an electronic device that outputs reproduction specification information when it receives a request signal representing the request. The electronic device includes a storage unit, a connector, a switching unit, a playback unit, and a control unit. The storage unit includes first information including information indicating reproduction specifications of the analog video signal, information for color adjustment of an image reproduced based on the analog video signal, and information indicating the reproduction specifications of the digital video signal. The second information is stored in a nonvolatile manner. The storage unit includes a control terminal for controlling the output of the first and second information. The storage unit outputs first information when a first level voltage is applied to the control terminal, and a second level voltage that is lower than the first level is applied to the control terminal. In this case, the second information is output. The connector is connected to an external device, and a request signal whose voltage level changes between the first and second levels and one video signal are input from the external device, and the first and second signals output from the storage unit One of the second information is output to the external device as reproduction specification information. The switching unit switches the connection destination of the control terminal between the voltage node to which the first level voltage is applied and the connector. The reproduction unit has a first mode for reproducing an analog video signal and a second mode for reproducing a digital video signal as operation modes for reproducing one video signal. The control unit controls the switching unit to connect the control terminal to the connector and to input a request signal to the control terminal. The control unit sets the operation mode of the reproduction unit to a mode corresponding to one of the first and second modes by controlling the reproduction unit based on the reproduction specification information output from the storage unit. To do. The control unit determines whether the corresponding mode is the first mode or the second mode by receiving the request signal. When the corresponding mode is the first mode, the control unit controls the switching unit so that the control terminal is connected to the voltage node during the period in which the operation mode of the reproducing unit is set to the first mode. The control unit controls the switching unit so that the control terminal is connected to the connector after setting the operation mode of the reproduction unit to the first mode.

  According to another aspect of the present invention, an external device capable of reproducing first and second video signals of different types and outputting one of the first and second video signals is An electronic device that outputs reproduction specification information when a request signal indicating a request for reproduction specification information corresponding to a video signal is received. The electronic device includes a storage unit, a connector, a switching unit, a playback unit, and a control unit. The storage unit stores, in a nonvolatile manner, first information including information indicating the reproduction specification of the first video signal and second information including information indicating the reproduction specification of the second video signal. The storage unit includes a control terminal for controlling the output of the first and second information. The storage unit outputs first information when a first level voltage is applied to the control terminal, and outputs second information when a second level voltage is applied to the control terminal. The connector is connected to an external device, and a request signal whose voltage level changes between the first and second levels and one video signal are input from the external device, and the first and second signals output from the storage unit One of the second information is output to the external device as reproduction specification information. The switching unit switches the connection destination of the control terminal between the voltage node to which the first level voltage is applied and the connector. The reproduction unit has a first mode for reproducing the first video signal and a second mode for reproducing the second video signal as operation modes for reproducing one of the video signals. . The control unit controls the switching unit to connect the control terminal to the connector and to input a request signal to the control terminal. The control unit sets the operation mode of the reproduction unit to a mode corresponding to one of the first and second modes by controlling the reproduction unit based on the reproduction specification information output from the storage unit. To do. The control unit determines whether the corresponding mode is the first mode or the second mode by receiving the request signal. When the corresponding mode is the first mode, the control unit controls the switching unit so that the control terminal is connected to the voltage node during the period in which the operation mode of the reproducing unit is set to the first mode. The control unit controls the switching unit so that the control terminal is connected to the connector after setting the operation mode of the reproduction unit to the first mode.

  Preferably, the switching unit can further set the connection destination of the control terminal to another voltage node to which a second level voltage is applied. When the corresponding mode is the second mode, the control unit controls the switching unit so that the control terminal is connected to another voltage node during the period in which the operation mode of the reproduction unit is set to the second mode. To do. The control unit controls the switching unit so that the control terminal becomes a connector after setting the operation mode of the reproduction unit to the second mode.

Preferably, the second level is lower than the first level.
More preferably, the first video signal is an analog video signal and the second video signal is a digital video signal.

  More preferably, the first information further includes information for color adjustment of an image reproduced based on the analog video signal.

  More preferably, the electronic device is a projector.

  According to the present invention, in an electronic device that stores analog-specific EDID data and digital-specific EDID data, even if a voltage change that is different from normal occurs in a connector that receives an external signal, the influence of the voltage change is avoided. Can do.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following description, a projector is shown as a specific example of the electronic apparatus according to the present embodiment. Note that the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated. In addition, the numerical values shown below are merely examples and do not limit the present embodiment.

  FIG. 1 is a diagram illustrating a configuration of a projector that is an example of an electronic apparatus according to the present embodiment. Referring to FIG. 1, projector 100 includes a connector 1, a main board 5, a light source 20, a light projecting unit 30, and an operation unit 70.

  The projector 100 has a function of reproducing a video signal in a form conforming to the HDMI standard from the source device 150. The projector 100 can reproduce both an analog video signal and a digital video signal. Therefore, the video signal output from the source device 150 may be either an analog signal or a digital signal.

  Prior to transmitting a video signal to the projector 100, the source device 150 requests the projector 100 to output EDID data. The EDID data corresponds to information indicating the reproduction specification of the projector 100.

  The source device 150 transmits a request signal indicating an acquisition request for EDID data. A request signal from the source device 150 is input to the connector 1 via the cable 2. Inside the projector 100, EDID data indicating the specification of the projector 100 for reproducing an analog video signal (hereinafter referred to as “analog EDID data”) and the specification of the projector 100 for reproducing a digital video signal are shown. EDID data (hereinafter referred to as “digital EDID data”) is stored. The EDID data includes, for example, information indicating the specifications / characteristics of the projector 100 (resolution, aspect ratio, full HD (High Definition) compatible, etc.).

  The projector 100 outputs analog EDID data when the voltage level of the received request signal is H (logic high) level. On the other hand, projector 100 outputs digital EDID data when the voltage level of the received request signal is L (logic low) level. Analog EDID data or digital EDID data is output from the connector 1 and input to the source device 150 by transmitting the cable 2. Here, the H level voltage is a voltage higher than a predetermined threshold voltage (for example, about 1.7 V), and the L level voltage is a voltage equal to or lower than the threshold voltage.

  As the connector 1, for example, a DVI-I connector that can handle both an analog video signal and a digital video signal may be used, or an M1 connector may be used.

  When the user operates the projector 100 (for example, powering on the projector, stopping the projector, etc.), the operation unit 70 outputs information indicating the details of the operation to the CPU 13. The CPU 13 performs processing according to the information.

  The main board 5 includes a playback unit 10, a CPU 13 (Central Processing Unit), and a memory 14. The reproduction unit 10 includes an A / D conversion unit 11, an image processing unit 12, and a channel switching unit 15.

  The reproducing unit 10 has a first mode for reproducing an analog video signal and an second mode for reproducing a digital video signal as an operation mode for reproducing a video signal input from the source device 150. Have. That is, the reproduction unit 10 reproduces an analog video signal when the operation mode is set to the first mode, and reproduces a digital video signal when the operation mode is set to the second mode.

  The channel switching unit 15 switches the output destination of the video signal received from the connector 1 (received from the source device 150) between the A / D conversion unit 11 and the image processing unit 12 according to the control of the CPU 13. When the video signal input to the channel switching unit 15 is an analog video signal, the CPU 13 outputs the analog video signal (signal AS shown in FIG. 1) from the channel switching unit 15 to the A / D conversion unit 11. Then, the channel switching unit 15 is controlled. Thus, the state in which the channel switching unit 15 is controlled corresponds to the first mode of the reproducing unit 10.

  When the video signal input to the channel switching unit 15 is a digital video signal, the CPU 13 outputs the digital video signal (signal DS shown in FIG. 1) from the channel switching unit 15 to the image processing unit 12. The channel switching unit 15 is controlled. Thus, the state in which the channel switching unit 15 is controlled corresponds to the second mode of the reproducing unit 10.

  The A / D converter 11 digitizes the analog video signal input from the source device 150. The image processing unit 12 is an image adjusted to the size of a screen (not shown) based on the digitized data output from the A / D conversion unit 11 or the digital data input from the channel switching unit 15. Is generated.

  When an image is generated from the analog video signal by the processing of the A / D conversion unit 11 and the image processing unit 12, the image processing unit 12 adjusts the color of the image (specifically, RGB gain). The image processing unit 12 receives calibration data for adjusting the color of the image from the CPU 13 and adjusts digital data output from the A / D conversion unit 11 based on this data.

  The memory 14 may be, for example, a RAM (Random Access Memory) that temporarily stores data necessary for the processing of the CPU 13, or a ROM (Read Only) that stores a program for causing the CPU 13 to execute processing in a nonvolatile manner. Memory).

  The light output from the light source 20 is sent to the light projecting unit 30. The light projecting unit 30 spatially modulates the light output from the light source 20 in accordance with the image output from the image processing unit 12 and projects the light onto a screen disposed in front.

  Specifically, the light projecting unit 30 includes a DMD 31 (Digital Mirror Device), a projection lens 32, a switching circuit 33, and a storage unit 34.

  The DMD 31 includes a plurality of micromirrors that are individually controlled. Each micromirror corresponds to one pixel. The micromirror reflects light from the light source 20 to the outside when it is on, and does not reflect light from the light source 20 to the outside when it is off.

  The switching circuit 33 switches the connection destination of the terminal T1 between the terminal T2 and the terminal T3 under the control of the CPU 13. Terminal T2 is connected to voltage node N to which the above-described H level voltage (eg, 3.3V voltage) is applied. This voltage node N is realized by a power supply circuit for supplying a power supply voltage to the CPU 13, for example.

  On the other hand, the terminal T3 receives a request signal from the source device 150 by being connected to the connector. Further, the terminal T3 is also connected to the CPU 13. As a result, the CPU 13 can receive a request signal from the source device 150. Based on the voltage level of the request signal, the CPU 13 grasps which of the analog EDID data and the digital EDID data is requested by the source device 150.

  The storage unit 34 includes a terminal T1, memory circuits 35 and 36, and an inverter 37. The control terminal of the memory circuit 35 is connected to the terminal T1. The input terminal of the inverter 37 is connected to the terminal T 1, and the output terminal of the inverter 37 is connected to the control terminal of the memory circuit 36. That is, the terminal T1 corresponds to a control terminal of the storage unit 34.

  The memory circuit 35 stores analog EDID data and calibration data in a nonvolatile manner. The memory circuit 36 stores digital EDID data in a nonvolatile manner. For example, the memory circuits 35 and 36 are EEPROM (Electrically Erasable Programmable Read Only Memory).

  Each of the memory circuits 35 and 36 outputs data to be stored when an H level voltage is input to its own control terminal, and does not output the data when an L level voltage is input.

  The memory circuit 35 outputs data D1 including analog EDID data and calibration data when the voltage level of the terminal T1 is H level, and does not output data D1 when the voltage level of the terminal T1 is L level.

  When the voltage level of the terminal T1 is L level, the output voltage level of the inverter 37 is H level. Therefore, the memory circuit 36 outputs data D2 including digital EDID data. On the other hand, when the voltage level of the terminal T1 is H level, the output voltage level of the inverter 37 is L level, so the memory circuit 36 does not output the data D2.

  In short, the storage unit 34 outputs data D1 when the voltage level of the terminal T1 is H level, and outputs data D2 when the voltage level of the terminal T1 is L level.

  The data D1 (or D2) output from the storage unit 34 is output from the connector 1 and input to the source device 150 via the cable 2. Thereby, the source device 150 acquires the EDID data of the projector 100. Further, the data D1 (or D2) output from the storage unit 34 is input to the CPU 13. The CPU 13 controls the A / D conversion unit 11, the image processing unit 12, and the channel switching unit 15 based on the received data, thereby setting the operation mode of the reproduction unit 10 to either the first mode or the second mode. To do.

  First, the CPU 13 controls the switching circuit 33 to connect the terminal T1 to the terminal T3 (that is, the connector 1) and to input a request signal to the terminal T1. When a request signal is input to the terminal T1, data (either data D1 or D2) corresponding to the voltage level of the request signal is output from the storage unit 34. The CPU 13 controls the playback unit 10 based on the data (playback specification information) output from the storage unit 34, so that the operation mode of the playback unit is output from the source device 150 out of the first and second modes. Set to the mode corresponding to the video signal (analog video signal or digital video signal).

  Furthermore, the CPU 13 determines whether the operation mode of the reproduction unit 10 corresponding to the video signal output from the source device 150 is the first mode or the second mode based on the voltage level of the request signal. When the mode is the first mode, the CPU 13 switches the switching circuit 33 so that the terminal T1 is connected to the terminal T2 (voltage node N) during the period in which the operation mode of the reproducing unit 10 is set to the first mode. To control. Then, after setting the operation mode of the reproduction unit 10 to the first mode, the CPU 13 controls the switching circuit 33 so that the terminal T1 is connected to the terminal T3 (connector). Thereby, while the CPU 13 sets the operation mode of the reproducing unit 10 to the first mode, the voltage level of the terminal T1 is kept at the H level.

  As described above, the CPU 13 controls the switching circuit 33, so that the cable 2 is disconnected from the connector 1 or the cable is inserted / removed while the CPU 13 sets the operation mode of the reproducing unit 10 to the first mode. In this case, the CPU 13 can correctly set the operation mode of the reproducing unit 10 (that is, set the operation mode to the first mode). Thereby, when the cable 2 is correctly connected to the connector 1, the projector 100 can appropriately process the analog video signal from the source device 150.

  When the voltage level of the request signal is L level, the CPU 13 does not change the connection destination of the terminal T1 while the operation mode of the reproducing unit 10 is set to the second mode. For this reason, the terminal T1 remains connected to the terminal T3. In this case, even if the cable 2 is disconnected from the connector 1 or the cable is inserted or removed, it can be expected that the signal level of the connector remains at the L level. Therefore, when the cable 2 is correctly connected to the connector 1, the projector 100 can be expected to appropriately process the digital video signal from the source device 150.

  In the electronic device of the present embodiment, the connection destination of the control terminal (terminal T1) of the storage unit 34 is switched between the connector 1 and a voltage node to which a predetermined level of voltage is applied. The effect obtained by such a configuration will be described in more detail.

  FIG. 2 is a diagram illustrating a comparative example of the present embodiment. Referring to FIG. 2, the control terminal of storage unit 34 is directly connected to connector 1. In this case, each time the voltage level of the request signal changes, different data is output from the storage unit 34. That is, when the voltage level of the request signal is H level, data D1 (analog EDID data and calibration data) is output from the memory circuit 35, and when the voltage level of the request signal is L level, the memory circuit 36 outputs data D2 (digital EDID data).

  A case where the source device 150 outputs an analog video signal will be described below. In this case, the source device 150 outputs an H level request signal. As a result, the data D1 is output from the memory circuit 35. The CPU 13 performs processing for setting the operation mode of the reproducing unit 10 (see FIG. 1) based on the data D1.

  However, if the cable 2 is disconnected from the connector 1 while the CPU 13 is performing the above processing, the voltage level of the request signal is likely to change from the H level to the L level. When the voltage level of the request signal changes from the H level to the L level, the data D2 is output from the memory circuit 36. Then, the CPU 13 performs a process for setting the operation mode of the reproducing unit 10 based on the data D2 (digital EDID data).

  That is, the operation mode of the playback unit 10 is switched from the first mode to the second mode. For this reason, even if the cable 2 is reconnected to the connector 1 and an analog video signal is input to the projector 100, the projector 100 cannot reproduce the video signal.

  In addition, since the data is input twice to the CPU 13, the data is overwritten inside the CPU 13. As a result, the calibration data is lost. For this reason, even if the projector 100 can reproduce an analog video signal, the color tone of the reproduced image may cause the user to feel uncomfortable.

  However, in the present embodiment, the terminal T1 is connected to the terminal T2 by the CPU 13 while the CPU 13 performs processing related to the setting of the operation mode of the reproducing unit 10 for the reproducing unit 10. For this reason, the voltage level of the terminal T1 is kept at the H level even when the cable 2 is disconnected from the connector 1 or the cable 2 is inserted / removed during the processing of the CPU 13. As a result, it is possible to prevent the digital EDID data from being output from the storage unit 34 after the data D1 (analog EDID data and calibration data) is once output from the storage unit 34. Therefore, the problem that the projector 100 cannot properly reproduce the analog video signal (the problem that the image cannot be reproduced or the color tone of the reproduced image greatly differs from the color tone of the image reproduced before that) is avoided. Can do.

  FIG. 3 is a flowchart schematically showing processing of the CPU 13 shown in FIG. The process shown in this flowchart is called from the main routine and executed every time a request signal is input to the CPU 13, for example.

  Referring to FIGS. 3 and 1, CPU 13 recognizes the type (analog or digital) of EDID data to be acquired by source device 150 based on a request signal from source device 150 (step S <b> 1). Next, the CPU 13 determines whether or not the type of the EDID data is analog EDID data (step S2).

  When the source device 150 intends to acquire analog EDID data (YES in step S2), the CPU 13 connects the terminal T1 and the terminal T2 by controlling the switching circuit 33 (step S3). Subsequently, the CPU 13 reads data D1 (analog EDID and calibration data) from the storage unit 34 (more specifically, the memory circuit 35). Further, the CPU 13 sets the operation mode of the reproduction unit 10 to the first mode (step S4). When the setting of the operation mode of the reproducing unit 10 is completed, the CPU 13 controls the switching circuit 33 to connect the terminal T1 and the terminal T3 (step S5).

  On the other hand, when the source device 150 intends to acquire digital EDID data (NO in step S2), the CPU 13 reads data D2 (digital EDID data) from the storage unit 34 (more specifically, the memory circuit 36). Further, the CPU 13 sets the operation mode of the reproduction unit 10 to the second mode (step S6).

When the process of step S5 or step S6 ends, the entire process ends.
(Modification)
FIG. 4 is a diagram showing a modification of the projector according to the present embodiment. Referring to FIG. 4, switching circuit 33 can switch the connection destination of terminal T <b> 1 between terminals T <b> 3, T <b> 2, T <b> 4 under the control of CPU 13. The terminal T4 is connected to the ground node to receive a ground voltage.

  When the source device 150 acquires digital EDID data, the CPU 13 controls the switching circuit 33 so that the terminals T1 and T4 are connected. As a result, the voltage level of the terminal T1 is fixed to the L level. Further, the CPU 13 sets the operation mode of the reproduction unit 10 to the second mode. When the setting of the operation mode of the reproducing unit 10 is completed, the CPU 13 controls the switching circuit 33 to connect the terminal T1 and the terminal T3. Thereby, while the CPU 13 sets the operation mode of the reproducing unit 10, the data output from the storage unit 34 can be only the data D2.

  The operation of the CPU 13 when the source device 150 acquires analog EDID data is the same as that described above. That is, according to the modification, the voltage level of the control terminal (terminal T1) of the storage unit 34 can be fixed when the CPU 13 sets the operation mode of the reproducing unit 10 to either the first or second mode. Therefore, according to this modification, the malfunction of the projector due to the fluctuation of the voltage of the connector 1 can be prevented more reliably than the configuration shown in FIG.

  In this modification, since the voltage level of the terminal T1 can be fixed to either the H level or the L level, the correspondence between the voltage level of the request signal and the data output from the storage unit 34 is as described above. It is not limited to. That is, the voltage of the request signal is such that the data D1 is output from the storage unit 34 when the voltage level of the request signal is L level, and the data D2 is output from the storage unit 34 when the voltage level of the request signal is H level. A correspondence relationship between the level and the output data of the storage unit 34 may be determined. For example, if the data stored in the memory circuits 35 and 36 are data D2 and D1, respectively, such a correspondence relationship is realized.

  In the projector according to the present embodiment, the DMD is used as an element for spatially modulating light. However, the present invention is not limited to this, and a liquid crystal panel may be used.

  Further, the electronic device of the present embodiment is not limited to a projector. The present invention can be applied to an electronic device that stores therein two different reproduction specification information and can switch between two signal reproduction processes based on the two data.

  Furthermore, the types of video signals are not limited to analog video signals and digital video signals. The present invention can be applied to any electronic device that can reproduce different types of video signals and store information of reproduction specifications for each type of video signal. Examples of different types of video signals include HD video signals and SD (Standard Definition) video signals.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure showing the structure of the projector which is an example of the electronic device which concerns on this embodiment. It is a figure which shows the comparative example of this Embodiment. It is a flowchart which shows roughly the process of CPU13 shown in FIG. It is a figure which shows the modification of the projector of this Embodiment.

Explanation of symbols

  1 connector, 2 cable, 5 main board, 10 playback unit, 11 A / D conversion unit, 12 image processing unit, 14 memory, 15 channel switching unit, 20 light source, 30 projection unit, 32 projection lens, 33 switching circuit, 34 storage unit, 35, 36 memory circuit, 37 inverter, 70 operation unit, 100 projector, 150 source device, N voltage node, T1 to T4 terminals.

Claims (7)

Represents a request for reproduction specification information corresponding to the one video signal from an external device capable of reproducing the analog video signal and the digital video signal and outputting one video signal of the analog video signal and the digital video signal. An electronic device that outputs the reproduction specification information when receiving a request signal,
Including first information including information indicating reproduction specifications of the analog video signal, information for color adjustment of an image reproduced based on the analog video signal, and information indicating reproduction specifications of the digital video signal A control terminal for storing the second information in a nonvolatile manner and controlling the output of the first and second information, and when a voltage of a first level is applied to the control terminal A storage unit that outputs first information and outputs the second information when a voltage of a second level that is lower than the first level is applied to the control terminal;
The request signal that is connected to the external device and changes in voltage level between the first and second levels and the one video signal are input from the external device and output from the storage unit. A connector for outputting one of the first and second information as the reproduction specification information to the external device;
A switching unit that switches a connection destination of the control terminal between a voltage node to which the voltage of the first level is applied and the connector;
A playback unit having a first mode for playing back the analog video signal and a second mode for playing back the digital video signal as operation modes for playing the one video signal;
By controlling the switching unit, the control terminal is connected to the connector, the request signal is input to the control terminal, and the reproduction unit is controlled based on the reproduction specification information output from the storage unit. A control unit configured to set the operation mode of the reproduction unit to a mode corresponding to the one video signal of the first and second modes;
The control unit determines whether the corresponding mode is the first mode or the second mode by receiving the request signal, and when the corresponding mode is the first mode, The switching unit is controlled so that the control terminal is connected to the voltage node during a period in which the operation mode of the reproduction unit is set to the first mode, and the operation mode of the reproduction unit is set to the first mode. An electronic device that controls the switching unit so that the control terminal is connected to the connector after setting the mode. Playback specifications corresponding to the one video signal from an external device capable of reproducing the first and second video signals of different types and outputting one of the first and second video signals. An electronic device that outputs the reproduction specification information when receiving a request signal indicating a request for information,
First information including information indicating the reproduction specification of the first video signal and second information including information indicating the reproduction specification of the second video signal are stored in a nonvolatile manner, and the first information is stored. And a control terminal for controlling the output of the second information, the first information is output when a voltage of the first level is applied to the control terminal, and the second level is output to the control terminal. A storage unit that outputs the second information when the voltage of
The request signal that is connected to the external device and changes in voltage level between the first and second levels and the one video signal are input from the external device and output from the storage unit. A connector for outputting one of the first and second information as the reproduction specification information to the external device;
A switching unit that switches a connection destination of the control terminal between a voltage node to which the voltage of the first level is applied and the connector;
Playback having a first mode for playing back the first video signal and a second mode for playing back the second video signal as operation modes for playing the one video signal And
By controlling the switching unit, the control terminal is connected to the connector, the request signal is input to the control terminal, and the reproduction unit is controlled based on the reproduction specification information output from the storage unit. A control unit configured to set the operation mode of the reproduction unit to a mode corresponding to the one video signal of the first and second modes;
The control unit determines whether the corresponding mode is the first mode or the second mode by receiving the request signal, and when the corresponding mode is the first mode, The switching unit is controlled so that the control terminal is connected to the voltage node during a period in which the operation mode of the reproduction unit is set to the first mode, and the operation mode of the reproduction unit is set to the first mode. An electronic device that controls the switching unit so that the control terminal is connected to the connector after setting the mode. The switching unit can further set the connection destination of the control terminal to another voltage node to which the second level voltage is applied,
In the control unit, when the corresponding mode is the second mode, the control terminal is connected to the other voltage node in a period in which the operation mode of the reproduction unit is set to the second mode. The switching unit is controlled so that the switching unit is controlled so that the control terminal becomes the connector after the operation mode of the reproduction unit is set to the second mode. The electronic device described.   The electronic device according to claim 2, wherein the second level is lower than the first level. The first video signal is an analog video signal;
5. The electronic device according to claim 2, wherein the second video signal is a digital video signal. 6.   The electronic apparatus according to claim 5, wherein the first information further includes information for color adjustment of an image reproduced based on the analog video signal.   The electronic device according to claim 2, wherein the electronic device is a projector.

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