Extender

In one embodiment, there is provided an extender for extending functions of an electronic apparatus. The extender includes: a connection terminal electrically connected to the electronic apparatus; input signal lines connected to the connection terminal to transmit a video signal that is supplied from the electronic apparatus via the connection terminal; a first video output terminal which complies with a first standard; a second video output terminal which complies with a second standard; and a signal converter configured to convert the video signal into a first video signal that complies with the first standard to output the first video signal to the first video output terminal and configured to convert the video signal into a second video signal that complies with the second standard to output the second video signal to the second video output terminal.

This application claims priority from Japanese Patent Application No. 2010-149101, filed on Jun. 30, 2010, the entire contents of which are hereby incorporated by reference.

BACKGROUND

Embodiments described herein generally relates to an extender for extending the functions of an electronic apparatus.

2. Description of the Related Art

Among portable electronic apparatus such as notebook personal computers and PDAs (personal digital assistants) are ones which can use an apparatus having functions to be added (extender) to extend functions usable by a user while maintaining their high portability. Each of an electronic apparatus and an extender is provided with a connection terminal for their electrical connection.

In general, an extender and an electronic apparatus are electrically connected to each other by a prescribed number of signal lines via their connection terminals. Signal exchange between the extender and the electronic apparatus is performed via the prescribed number of signal lines.

One of signals that are exchanged by an extender and an electronic apparatus is a video signal. Various techniques using their own signal transmission methods have been proposed to decrease the number of signal lines relating to a video signal. These techniques can decrease the number of signal lines relating to a video signal and thereby miniaturize the connection terminals for connection between an extender and an electronic apparatus.

DETAILED DESCRIPTION

According to exemplary embodiments of the present invention, there is provided an extender for extending functions of an electronic apparatus. The extender includes: a connection terminal electrically connected to the electronic apparatus; input signal lines connected to the connection terminal so as to transmit a video signal that is supplied from the electronic apparatus via the connection terminal, wherein the number the input signal lines complies with a certain video signal standard; a first video output terminal which complies with a first standard; a second video output terminal which complies with a second standard; and a signal converter configured to convert the video signal that is supplied from the electronic apparatus into a first video signal that complies with the first standard so as to output the first video signal to the first video output terminal and configured to convert the video signal into a second video signal that complies with the second standard so as to output the second video signal to the second video output terminal.

Extender according to embodiments of the present invention will be hereinafter described with reference to the accompanying drawings.

Each of the extender according to the embodiments of the invention is an extender for extending the functions of an electronic apparatus. The extender has video output terminals that comply with plural respective standards and decreases the number of signal lines relating to a video signal that are electrically connected to an electronic apparatus via connection terminals. The following description will be directed to a case that the electronic apparatus connected to the extender according to each embodiment of the invention is a notebook personal computer (hereinafter referred to as a notebook PC). However, in the invention, the electronic apparatus is not limited to a notebook PC and may be a PDA (personal digital assistant), a portable game machine, a portable music player, a portable moving image player, or the like.

(1) First Embodiment

FIG. 1is a perspective view of an extender according to a first embodiment of the invention and a notebook PC20as an electronic apparatus to be connected to the extender10.

The extender10is an apparatus which is provided with functions to be added to extend functions usable by a user while maintaining high portability of the notebook PC20. The extender10has a base unit11containing various circuits and an extender-side connection terminal12for electrical connection to the notebook PC20. In the embodiment, as shown inFIG. 1, the extender10also has a video output terminal (RGB socket)13that complies with the analog RGB standard which was standardized by the VESA (Video Electronics Standards Association), an HDMI socket14that complies with the HDMI (high-definition multimedia interface) standard, and a video output terminal (DP socket) that complies with the DisplayPort standard (DP standard).

An RGB plug101is to be connected to the RGB socket13. The RGB socket13outputs a video signal that complies with the analog RGB standard to an external display device102(monitor display) that is connected to the RGB plug101and is compatible with the analog RGB standard, via the RGB plug101.

An HDMI plug103is to be connected to the HDMI socket14. The HDMI socket14outputs a video signal that complies with the HDMI standard to an external display device104that is connected to the HDMI plug103and is compatible with the HDMI standard, via the HDMI plug103. A DP plug105is to be connected to the DP socket15. The DP socket15outputs a video signal that complies with the DP standard to an external display device106that is connected to the DP plug105and is compatible with the DP standard, via the DP plug105.

The notebook PC20is equipped with a computer main body21and a display unit22which is a display device. The computer main body21has a thin, box-shaped cabinet and the bottom surface of the cabinet is provided with a PC-side connection terminal23that can be electrically connected to the extender-side connection terminal12of the extender10. For example, one of the extender-side connection terminal12and the PC-side connection terminal23projects from the cabinet of the extender10or the notebook PC20by a prescribed length and the other is recessed so as to be fitted with the one connection terminal12or23.

A rear portion of the top surface of the cabinet of the computer main body21is provided with a keyboard24which is a manipulation unit. A front portion of the cabinet is provided with a palm rest. A central portion of the palm rest is provided with a touch pad25and touch pad buttons26which constitute another manipulation unit. On the other hand, the display unit22has a display panel27and is connected to the computer main body21by connection members (hinges)28which support the display unit22so that it can be opened and closed.

The manipulation units (keyboard24and touch pad25/touch pad buttons26) supplies a main controller32(seeFIG. 2) of the notebook PC20with an input manipulation signal corresponding to a user manipulation. The display panel27, which is a general display output device such as a liquid crystal display, an OLED (organic light-emitting diode) display, or an LED (light-emitting diode) display, displays various kinds of information under the control of the main controller32.

FIG. 2is a block diagram outlining example internal configurations of the extender10and the notebook PC20shown inFIG. 1.

As shown inFIG. 2, the notebook PC20is further equipped with signal lines30the number of which is at least equal to a number that complies with a prescribed video signal standard, a GPU (graphics processing unit)31having an image processing function, and the main controller32. Controlled by the main controller32, the GPU31outputs a video signal that complies with the prescribed video signal standard to the extender10via the signal lines30and the PC-side connection terminal23to which the signal lines30are connected. The main controller32is composed of a CPU, storage media such as a RAM and a ROM, etc., and controls operations of the notebook PC20according to programs stored in those storage media.

On the other hand, the extender10is further equipped with signal lines the number of which complies with the prescribed video signal standard and which are connected to the extender-side connection terminal12, a DP power controller45, and a signal converter50.

The signal lines40, which are electrically connected to the signal lines30via the PC-side connection terminal23, supply the signal converter50with a video signal that is output from the GPU31.

The signal converter50receives a video signal that complies with the prescribed video signal standard from the GPU31via the signal lines30, the PC-side connection terminal23, the extender-side connection terminal12, and the signal lines40. The signal converter50converts the received video signal which complies with the prescribed video signal standard into a video signal that complies with the video signal standard corresponding to one of the video output terminals13-15of the extender10and outputs the latter video signal to that video output terminal.

For example, assume that the extender10has video output terminals that comply with first and second standards and the GPU31outputs a video signal that complies with a third standard. In this case, when receiving a video signal that complies with the third standard, the signal converter50converts the received video signal into a video signal that complies with the first standard and outputs it to the video output terminal that complies with the first standard. Or the signal converter50converts the received video signal into a video signal that complies with the second standard and outputs it to the video output terminal that complies with the second standard.

If the standard corresponding to a destination video output terminal is the same as the standard with which a video signal that is output from the GPU31complies, the signal converter50outputs a video signal that complies with that standard. This means that the signal converter50outputs the received video signal to the target video output terminal as it is without converting it.

The following description will be directed to a case that the extender10is equipped with the RGB socket13, the HDMI socket14, and the DP socket15and the GPU31outputs a video signal that complies with the physical layer standard and the logical layer standard of the DP standard (i.e., a video signal that complies with the DP standard) or a video signal that complies with the logical layer standard of the HDMI standard, and the video signal is transmitted by signal lines30and40that comply with the DP standard.

In this case, the number of lines of each of the set of signal lines30and the set of signal lines40is at least equal to the number that complies with the DP standard. The number of lines that complies with the DP standard is eleven, that is, ten for transmission of differential signals (two is of sideband signal lines corresponding to signal lines for transmission of a DDC (VESA display data channel) signal that complies with the HDMI standard or the like) plus one for transmission of a hot plug signal.

The embodiment is directed to a case that each of the set of signal lines30and the set of signal lines40further has two signal lines for power control via which the GPU31supplies an instruction to the DP power controller45. Therefore, each of the set of signal lines30and the set of signal lines40has 13 lines in total.

The number of lines that complies with the analog RGB standard is seven, that is, three for transmission of R, G, and B signals, two for transmission of a sync signal, and two for transmission of a DDC signal. The number of lines that complies with the HDMI standard is eleven, that is, eight for transmission of differential signals, two for transmission of a DDC signal, and one for transmission of a hot plug signal.

The DP power controller45is controlled by the GPU31via the two signal lines for power control and controls the supply of power to the DP socket15.

The signal converter50is equipped with a DP-to-analog-RGB conversion IC (integrated circuit) (hereinafter referred to as a RGB converter)51, an HDMI bias circuit (hereinafter referred to as a HDMI converter)52, and a DP converter53. Signal lines that comply with the same video standard as the signal lines30and50do are connected to the video signal input side (GPU31side) of each of the converters51-53. Sets of signal lines that comply with the video signal standards corresponding to the sockets13-15are connected to the video signal output sides (the sides of the sockets13-15) of the converters51-53, respectively.

The RGB converter (DP-to-analog-RGB conversion IC)51converts a video signal that is output from the GPU31and complies with the DP standard into a video signal that complies with the analog RGB standard, and outputs the latter video signal to the RGB socket13.

Furthermore, the RGB converter51monitors the output potential of the RGB socket13. The RGB socket13outputs a high-level potential when the RGB plug101is connected to it, and outputs a low-level potential when the RGB plug101is not connected to it. Utilizing the output potential of the RGB socket13as a connection recognition signal, the RGB converter51generates a signal (HPL_RGB signal) that is equivalent to a hot plug signal (HPL_HDMI signal) to be output from the HDMI socket and a hot plug signal (HPL_DP signal) to be output from the DP socket15, and outputs the generated signal to the GPU-side signal lines.

In other words, the RGB socket13is configured so as to output a connection recognition signal to the signal converter50when the RGB plug101is connected to it. Each of the HDMI socket14and the DP socket15outputs a hot plug signal (connection recognition signal) to the signal converter50when the HDMI plug103or the DP plug105is connected to it. InFIG. 2, signal lines for transmission of a connection recognition signal are drawn by broken lines.

The HDMI converter (HDMI bias circuit)52converts a video signal that is output from the GPU31and complies with the logical layer standard of the HDMI standard into a video signal that complies with the physical layer standard of the HDMI standard by adjusting a bias voltage (physical layer information) of the former video signal, and outputs the latter video signal to the HDMI socket14. As a result, the video signal that is output from the HDMI converter52is a video signal that complies with the physical layer standard and the logical layer standard of the HDMI standard.

The HDMI converter52receives a hot plug signal (HPL_HDMI signal) that is output from the HDMI socket14, and outputs it to the GPU-side signal lines as it is.

The DP converter53is a section for outputting a video signal that is output from the GPU31and complies with the DP standard to the DP socket15as it is. The DP converter53is therefore formed by simple wiring lines (signal lines) that comply with the DP standard.

The DP converter53receives a hot plug signal (HPL_DP signal) that is output from the DP socket15, and outputs it to the GPU-side signal lines as it is.

A connection recognition signal that is supplied to the signal converter50is transferred to the GPU31via the signal lines40, the extender-side connection terminal12, the PC-side connection terminal23, and the signal lines30.

The embodiment is directed to a case that the signal converter50outputs a video signal to a selected one of the sockets13-15. In this case, the signal converter50has a switching module55.

The switching module55is equipped with a first multiplexer (MUX)56and a second multiplexer57.

The first multiplexer56supplies a video signal that is received from the GPU31to one of the RGB converter51or the second multiplexer57. The first multiplexer56receives, as a switching control signal, an HPL_RGB signal that is generated by the RGB converter51by converting a connection recognition signal that is output from the RGB socket13.

For example, the HPL_RGB signal is input to the first multiplexer56as a switching control signal via a new single signal line produced by one-to-two branching of one signal line for transmission of a hot plug signal that is included in the signal lines that connect one output terminal of the first multiplexer56to the RGB converter51.

As shown inFIG. 2, the first multiplexer56connects the signal lines40to the RGB converter51if the HPL_RGB signal is at a high level (indicated by a number “1” shown in the first multiplexer56inFIG. 2), and connects the signal lines40to the second multiplexer57if the HPL_RGB signal is at a low level (indicated by a number “0” shown in the first multiplexer56inFIG. 2). In the following description, a connection recognition signal at the high level is represented by “1” and a connection recognition signal at the low level is represented by “0.”

The second multiplexer57supplies the video signal received from the first multiplexer56to one of the HDMI converter52and the DP converter53. The second multiplexer57receives, as a switching control signal, via the HDMI converter52, a connection recognition signal (HPL_HDMI signal) that is output from the HDMI socket14.

As in the case of the above-described HPL_RGB signal, an HPL_HDMI signal is input to the second multiplexer57as a switching control signal via, for example, a new single signal line produced by one-to-two branching of one signal line for transmission of a hot plug signal that is included in the signal lines that connect one output terminal of the second multiplexer57to the HDMI converter52.

As shown inFIG. 2, the second multiplexer57connects the first multiplexer56to the HDMI converter52if the HPL_HDMI signal is at the high level “1,” and connects the first multiplexer56to the DP converter53if the HPL_HDMI signal is at the low level “0.”

(1-2) Operations in a Case that Highest Priority is Given to Connection to RGB Socket13

FIGS. 3A and 3Bshow example operations of the signal converter50in a case that a highest priority is given to connection to the RGB socket13. More specifically,FIG. 3Ashows an example operation of the signal converter50in a case that a higher priority is given to connection, made by the extender10shown inFIG. 2, to the HDMI socket14than to connection to the DP socket15.FIG. 3Bshows an example operation of the signal converter50in a case that a higher priority is given to connection to the DP socket15than to connection to the HDMI socket14.

(1-2-1) Case that Higher Priority is Given to Connection to HDMI Socket14than to Connection to DP Socket15

As shown inFIGS. 2 and 3A, in the configuration ofFIG. 2, a highest priority is given to connection to the RGB socket13and a higher priority is given to connection to the HDMI socket14than to connection to the DP socket15. More specifically, if the RGB plug101is connected to the RGB socket13and hence an HPL_RGB signal at the high level “1” is input to the first multiplexer56, a video signal received from the GPU31is supplied to the RGB converter51irrespective of connection statuses of the other sockets14and15and converted into a video signal that complies with the analog RGB standard, which is output to the RGB socket13.

If the RGB plug101is not connected to the RGB socket13and hence an HPL_RGB signal at the low level “0” is input to the first multiplexer56and if the HDMI plug103is connected to the HDMI socket14and hence an HPL_HDMI signal at the high level “1” is input to the second multiplexer57, a video signal received from the GPU31is supplied to the HDMI converter52irrespective of the connection status of the DP socket15and converted into a video signal that complies with the HDMI standard, which is output to the HDMI socket14.

For example, consideration will be given to a case that the RGB plug101is connected to the RGB socket13. In this case, since an HPL_RGB signal at the high level “1” is generated, the first multiplexer56connects the signal lines40to the RGB converter51irrespective of connection statuses of the other sockets14and15. As a result, whereas the signal lines40are electrically connected to the RGB converter51the signal lines40are disconnected from the other sockets14and15.

The RGB socket13is electrically connected to the GPU31of the notebook PC20via the RGB converter51and the first multiplexer56. Therefore, the HPL_RGB signal that is generated by the RGB converter51on the basis of a connection recognition signal that is output from the RGB socket13is supplied to the GPU31.

When receiving the HPL_RGB signal, the GPU31receives information to the effect that the external display device102which is connected to the RGB socket13is a display device that is compatible with the analog RGB standard, in the form of data having, for example, the EDID (extended display identification data) format from the external display device102via the DDC signal lines. Then, the GPU31outputs a video signal that complies with the DP standard to the signal lines30which comply with the DP standard. The video signal is supplied to the RGB converter51and converted into a video signal that complies with the analog RGB standard, which is output to the analog-RGB-compatible external display device102via the RGB socket13and the RGB plug101.

Consideration will be given to another case that the HDMI plug103is connected to the HDMI socket14and no plugs are connected to the other sockets13and15. In this case, an HPL_RGB signal of “0” and an HPL_HDMI signal of “1” are generated. Therefore, the first multiplexer56connects the signal lines40to the second multiplexer57and the second multiplexer57connects the first multiplexer56to the HDMI converter52.

The HDMI socket14is electrically connected to the GPU31of the notebook PC20via the HDMI converter52, the second multiplexer57, and the first multiplexer56. Therefore, the HPL_HDMI signal that is output from the HDMI socket14is supplied to the GPU31. When receiving the HPL_RGB signal, the GPU31receives information to the effect that the external display device104which is connected to the HDMI socket14is a display device that is compatible with the HDMI standard, in the form of data having, for example, the EDID format from the external display device104via the DDC signal lines.

Then, the GPU31outputs a video signal that complies with the logical layer standard of the HDMI standard to the signal lines30which comply with the DP standard. The video signal is supplied to the HDMI converter52and converted, through bias voltage (physical layer information) adjustment, into a video signal that complies with the physical layer standard of the HDMI standard, which is output to the HDMI-compatible external display device104via the HDMI socket14and the HDMI plug103.

For still another example, consideration will be given to a case that the DP plug105is connected to the DP socket15and no plugs are connected to the other sockets13and14. In this case, an HPL_RGB signal of “0” and an HPL_HDMI signal of “0” are generated. Therefore, the first multiplexer56connects the signal lines40to the second multiplexer57and the second multiplexer57connects the first multiplexer56to the DP converter53.

The DP socket15is electrically connected to the GPU31of the notebook PC20via the DP converter53, the second multiplexer57, and the first multiplexer56. Therefore, an HPL_DP signal that is output from the DPI socket15is supplied to the GPU31. When receiving the HPL_DP signal, the GPU31receives information to the effect that the external display device106which is connected to the DP socket15is a display device that is compatible with the DP standard, in the form of data having, for example, the EDID format from the external display device106via the DDC signal lines.

Then, the GPU31outputs a video signal that complies with the DP standard to the signal lines30which comply with the DP standard. The video signal is supplied to the DP converter53, supplied to the DP socket15as it is, and output to the DP-compatible external display device106via the DP socket15and the DP plug105.

(1-2-2) Case that Higher Priority is Given to Connection to DP Socket15than to Connection to HDMI Socket14

Another configuration is possible which is different from the configuration ofFIG. 2in that as shown inFIG. 3Ban HPL_DP signal is input to the second multiplexer57as a switching control signal instead of an HPL_HDMI signal. In this configuration, a highest priority is given to connection to the RGB socket13and a higher priority is given to connection to the DP socket15than to connection to the HDMI socket14.

Where the signal converter50outputs a video signal to a selected one of the sockets13-15, an arbitrary priority order can be set by properly setting a manner of connections between the switching module55and the converters51-53and determining switching control signals to be input to the switching module55.

(1-3) Operations in a Case that Highest Priority is Given to Connection to HDMI Socket14

Next, to verify that priority order can be set arbitrarily, another example of priority order in which a highest priority is given to connection to the HDMI socket14will be described briefly.

FIG. 4is a block diagram showing a modified signal converter50in a case that a highest priority is given to connection to the HDMI socket14.FIGS. 5A and 5Bshow example operations of the signal converter50in a case that a highest priority is given to connection to the HDMI socket14. More specifically,FIG. 5Ashows an example operation of the signal converter50in a case that a higher priority is given to connection, made by the extender10shown inFIG. 4, to the RGB socket13than to connection to the DP socket15.FIG. 5Bshows an example operation of the signal converter50in a case that a higher priority is given to connection to the DP socket15than to connection to the RGB socket13.

(1-3-1) Case that Higher Priority is Given to Connection to RGB Socket13than to Connection to DP Socket15

As shown inFIGS. 4 and 5A, in the configuration ofFIG. 4, a highest priority is given to connection to the HDMI socket14and a higher priority is given to connection to the RGB socket13than to connection to the DP socket15. More specifically, if the HDMI plug103is connected to the HDMI socket14and hence an HPL_RGB signal at the high level “1” is input to the first multiplexer56, a video signal received from the GPU31is supplied to the HDMI converter52irrespective of connection statuses of the other sockets13and15and converted into a video signal that complies with the HDMI standard, which is output to the HDMI socket14.

(1-3-2) Case that Higher Priority is Given to Connection to DP Socket15than to Connection to RGB Socket13

Another configuration is possible which is different from the configuration ofFIG. 4in that as shown inFIG. 5Ban HPL_DP signal is input to the second multiplexer57as a switching control signal instead of an HPL_RGB signal. In this configuration, a highest priority is given to connection to the HDMI socket14and a higher priority is given to connection to the DP socket15than to connection to the RGB socket13.

Any other arbitrary priority order such as one in which highest priority is given to connection to the DP socket15can be set easily.

The extender10according to the embodiment has the video output terminals (sockets)13-15which comply with the three different video standards, (analog RGB standard, HDMI standard, and DP standard) and outputs a video signal to a selected one of the sockets13-15. And the extender10receives a video signal from the notebook PC20via the signal lines30and the signal lines40the number of which complies with the prescribed video standard (DP standard).

Therefore, the extender10according to the embodiment can output video signals that comply with the plural respective video standards while reducing the number of pins of the extender-side connection terminal12. Therefore, not only the extender-side connection terminal12but also the connection terminal23of the notebook PC20can be miniaturized. The extender10thus makes it possible to miniaturize an electronic apparatus to be connected to it.

The extender10according to the embodiment can automatically output, to a selected one of the plural video output terminals, a video signal that complies with the video standard corresponding to the selected video output terminal according to a preset priority order and connection statuses of the respective video output terminals.

The extender10according to the embodiment uses a DP-to-analog-RGB conversion IC as the conversion-to-RGB section51. Therefore, even where an electronic apparatus connected to the extender10does not have a function of outputting a video signal that complies with the analog RGB standard, if the electronic apparatus can output a video signal that complies with the DP standard, the extender10can output a video signal that complies with the analog RGB standard through conversion of the video signal that complies with the DP standard. Therefore, where, for example, a user has an electronic apparatus that cannot output a video signal that complies with the analog RGB standard and an analog-RGB-compatible external display device (102), the extender10can mediate between the electronic apparatus and the analog-RGB-compatible external display device (102).

In a configuration in which the GPU31outputs a video signal that complies with the analog RGB standard (or HDMI standard) and the signal lines30and the signal lines40are signal lines that comply with the analog RGB standard (or HDMI standard), the converters51-53of the signal converter50may be configured so as to convert a received video signal into video signals that comply with the output destination sockets13-15, respectively.

Another configuration is possible in which the switching module55is omitted and a video signal that is output from the GPU31is supplied equally to all the converters51-53. In this case, a video signal that is output from the GPU31is converted by the converters51-53and resulting video signals are output to the sockets13-15, respectively. Since a video signal has a high frequency, if the switching module55is omitted, it is preferable to take a proper measure to secure the quality of a high-frequency signal. For example, this may be done by minimizing the total length of the signal lines relating to the embodiment that are provided in the extender10and thereby preventing interference with other signal lines.

(2) Second Embodiment

FIG. 6is a block diagram outlining example internal configurations of an extender10A according to a second embodiment and a notebook PC20.

The extender10A according to the second embodiment is different from the extender10according to the first embodiment in that the former is not equipped with the DP socket15, the DP power controller45, the DP converter53, and the second multiplexer57. Since the other part of the configuration and related workings are substantially the same as in the extender10according to the first embodiment, members, sections, etc. having the same ones in the extender10according to the first embodiment are given the same reference symbols as the latter and will not be described in detail.

In the configuration ofFIG. 6in which the RGB converter51is connected to the “1”-side output terminal of the multiplexer56and an HPL_RGB signal is input to the multiplexer56as a switching control signal, a higher priority is given to connection to the RGB socket13than to connection to the HDMI socket14. In another configuration in which the HDMI converter52is connected to the “1”-side output terminal of the multiplexer56and an HPL_HDMI signal is input to the multiplexer56as a switching control signal, a higher priority is given to connection to the HDMI socket14than to connection to the RGB socket13.

Since the extender10A according to the second embodiment is not equipped with the DP socket15, the DP power controller45for supplying power to the DP socket15is not necessary. Therefore, among the signal lines30(13 lines in total) and the signal lines40(13 lines in total) of the extender10according to the first embodiment, the two signal lines for power control are not necessary.

The extender10A according to the second embodiment can output video signals that comply with the plural respective video standards while reducing the number of pins of the extender-side connection terminal12. The extender10A according to the second embodiment can automatically output, to a selected one of the plural video output terminals, a video signal that complies with the video standard corresponding to the selected video output terminal according to a preset priority order and connection statuses of the respective video output terminals. Furthermore, where, for example, a user has an electronic apparatus that cannot output a video signal that complies with the analog RGB standard and an analog-RGB-compatible external display device (102), the extender10A can mediate between the electronic apparatus and the analog-RGB-compatible external display device (102). The electronic apparatus and the analog-RGB-compatible external display device (102) can thus be used effectively instead of being rendered useless.

FIG. 7is a block diagram outlining example internal configurations of an extender10B according to a third embodiment and a notebook PC20.

The extender10B according to the third embodiment is different from the extender10according to the first embodiment in that the former is not equipped with the HDMI socket14, the HDMI converter52, and the second multiplexer57. Since the other part of the configuration and related workings are substantially the same as in the extender10according to the first embodiment, members, sections, etc. having the same ones in the extender10according to the first embodiment are given the same reference symbols as the latter and will not be described in detail.

In the configuration ofFIG. 7in which the RGB converter51is connected to the “1”-side output terminal of the multiplexer56and an HPL_RGB signal is input to the multiplexer56as a switching control signal, a higher priority is given to connection to the RGB socket13than to connection to the DP socket15. In another configuration in which the DP converter53is connected to the “1”-side output terminal of the multiplexer56and an HPL_DP signal is input to the multiplexer56as a switching control signal, a higher priority is given to connection to the DP socket15than to connection to the RGB socket13.

The extender10B according to the third embodiment can output video signals that comply with the plural respective video standards while reducing the number of pins of the extender-side connection terminal12. The extender10B according to the third embodiment can automatically output, to a selected one of the plural video output terminals, a video signal that complies with the video standard corresponding to the selected video output terminal according to a preset priority order and connection statuses of the respective video output terminals. Furthermore, where, for example, a user has an electronic apparatus that cannot output a video signal that complies with the analog RGB standard and an analog-RGB-compatible external display device (102), the extender10B can mediate between the electronic apparatus and the analog-RGB-compatible external display device (102). The electronic apparatus and the analog-RGB-compatible external display device (102) can thus be used effectively instead of being rendered useless.

FIG. 8is a block diagram outlining example internal configurations of an extender10C according to a fourth embodiment and a notebook PC20.

The extender10C according to the fourth embodiment is different from the extender10according to the first embodiment in that the former is not equipped with the RGB socket13, the RGB converter51, and the second multiplexer57. Since the other part of the configuration and related workings are substantially the same as in the extender10according to the first embodiment, members, sections, etc. having the same ones in the extender10according to the first embodiment are given the same reference symbols as the latter and will not be described in detail.

In the configuration ofFIG. 8in which the HDMI converter52is connected to the “1”-side output terminal of the multiplexer56and an HPL_HDMI signal is input to the multiplexer56as a switching control signal, a higher priority is given to connection to the HDMI socket14than to connection to the DP socket15. In another configuration in which the DP converter53is connected to the “1”-side output terminal of the multiplexer56and an HPL_DP signal is input to the multiplexer56as a switching control signal, a higher priority is given to connection to the DP socket15than to connection to the HDMI socket14.

The extender10C according to the fourth embodiment can output video signals that comply with the plural respective video standards while reducing the number of pins of the extender-side connection terminal12. Furthermore, the extender10C according to the fourth embodiment can automatically output, to a selected one of the plural video output terminals, a video signal that complies with the video standard corresponding to the selected video output terminal according to a preset priority order and connection statuses of the respective video output terminals.

As in the extender10according to the first embodiment, each of the extender10A-10C according to the second to fourth embodiments may be modified in such a manner that the switching module55is omitted and a video signal that is output from the GPU31is supplied equally to all the converters.

FIG. 9is a block diagram outlining example internal configurations of an extender10D according to a fifth embodiment and a notebook PC20.

The extender10D according to the fifth embodiment is different from the extender10according to the first embodiment in that the former is equipped with a first switch61for outputting a switching control signal to the first multiplexer56and a second switch62for outputting a switching control signal to the second multiplexer57. Since the other part of the configuration and related workings are substantially the same as in the extender10according to the first embodiment, members, sections, etc. having the same ones in the extender10according to the first embodiment are given the same reference symbols as the latter and will not be described in detail.

When manipulated by a user, the first switch61outputs a switching control signal to the first multiplexer56. When manipulated by the user, the second switch62outputs a switching control signal to the second multiplexer57.

FIG. 10shows an example operation of the signal converter50in a case that a highest priority is given to connection to the RGB socket13made by the extender10D ofFIG. 9.

In the configuration ofFIG. 9in which one of the output terminals of the first multiplexer56is connected to the RGB converter51, if the first switch61outputs a high-level switching control signal, a video signal that is output from the GPU31is supplied to the RGB converter51irrespective of the content of a switching control signal that is output from the second switch62and converted into a video signal that complies with the analog RGB standard, which is output to the RGB socket13.

Therefore, in the configuration ofFIG. 9, the first switch61functions as a switch for receiving an instruction as to whether to output a video signal to the RGB socket13(seeFIG. 10). Therefore, for example, the first switch61may be such as to output, as a switching control signal, a signal equivalent to an HPL_RGB signal.

In the configuration ofFIG. 9, the second switch62functions as a switch for receiving an instruction as to which of the HDMI socket14and the DP socket15a video signal should be output to in the case where the first switch61outputs a low-level switching control signal. It can be said that connection to the HDMI socket14and connection to the DP socket15are dealt with equivalently as long as the first switch61outputs a low-level switching control signal.

Naturally, the second switch62may be used as a switch for receiving an instruction as to whether to output a video signal to the HDMI socket14in the case where the first switch61outputs a low-level switching control signal. In this case, the second switch62may be such as to output, as a switching control signal, a signal equivalent to an HPL_HDMI signal.

The extender10D according to the fifth embodiment can output video signals that comply with the plural respective video standards while reducing the number of pins of the extender-side connection terminal12. The extender10D according to the fifth embodiment can output, to a selected one of the plural video output terminals, a video signal that complies with the video standard corresponding to the selected video output terminal according to a preset priority order and a user manipulation(s) on the switches61and62which are provided in the extender10D. Furthermore, where, for example, a user has an electronic apparatus that cannot output a video signal that complies with the analog RGB standard and an analog-RGB-compatible external display device (102), the extender10D can mediate between the electronic apparatus and the analog-RGB-compatible external display device (102). The electronic apparatus and the analog-RGB-compatible external display device (102) can thus be used effectively instead of being rendered useless.

In connection with the extender10D according to the fifth embodiment, as in the case of the extender10according to the first embodiment, an arbitrary priority order other than the above described one, such as one in which a highest priority is given to connection to the HDMI socket14, can be set easily (refer toFIG. 4, for example). Where there are only two video output terminals as in the cases of the extender10A-10C according to the second to fourth embodiments, it suffices that only one multiplexer and hence only one switch be provided.

Like the extender10according to the first embodiment, the extender10D according to the fifth embodiment may be modified in such a manner that the switching module55is omitted and a video signal that is output from the GPU31is supplied equally to all the converters51-53.

FIG. 11is a block diagram outlining example internal configurations of an extender10E and a notebook PC20E according to a sixth embodiment.

The extender10E according to the sixth embodiment is different from the extender10according to the first embodiment in that the former has a single, first signal line41for supplying a switching control signal to the first multiplexer56from a notebook PC20E and a single, second signal line42for supplying a switching control signal to the second multiplexer57from the notebook PC20E and that switching control signals are supplied to the first multiplexer56and the second multiplexer57from the notebook PC20E. Since the other part of the configuration and related workings are substantially the same as in the extender10according to the first embodiment, members, sections, etc. having the same ones in the extender10according to the first embodiment are given the same reference symbols as the latter and will not be described in detail.

The notebook PC20E is further equipped with a PCH (platform controller hub)33, a first GPIO (general-purpose input/output)34, and a second GPIO.

The main controller32displays, on the display panel27, a selection request image for causing a user to select one of the output destination sockets13-15. The main controller32receives instruction information that is input by the user through the selection request image by manipulating a manipulation unit.

The PCH33is a chip in which I/O controller functions of various devices are integrated. In response to instruction information that is input by a user, the main controller32supplies a switching control signal to the first multiplexer56via the PCH33and the first GPIO34and supplies another switching control signal to the second multiplexer57via the PCH33and the second GPIO35.

FIG. 12shows an example operation of the signal converter50in a case that a highest priority is given to connection to the RGB socket13made by the extender10E ofFIG. 11.

In the configuration ofFIG. 11in which one of the output terminals of the first multiplexer56is connected to the RGB converter51, if the first GPIO34outputs a high-level switching control signal, a video signal that is output from the GPU31is supplied to the RGB converter51irrespective of the content of a switching control signal that is output from the second GPIO35and converted into a video signal that complies with the analog RGB standard, which is output to the RGB socket13.

Therefore, in the configuration ofFIG. 11, the first GPIO34outputs a switching control signal indicating whether to output a video signal to the RGB socket13(seeFIG. 12). Therefore, for example, the first GPIO34may output, as a switching control signal, a signal equivalent to an HPL_RGB signal.

In the configuration ofFIG. 11, the second GPIO35outputs a switching control signal indicating which of the HDMI socket14and the DP socket15a video signal should be output to in the case where the first GPIO34outputs a low-level switching control signal. It can be said that connection to the HDMI socket14and connection to the DP socket15are dealt with equivalently as long as the first GPIO34outputs a low-level switching control signal.

Naturally, the second GPIO35may be regarded as a section for outputting a switching control signal indicating whether to output a video signal to the HDMI socket14in the case where the first GPIO34outputs a low-level switching control signal. In this case, the GPIO35may output, as a switching control signal, a signal equivalent to an HPL_HDMI signal.

The extender10E according to the sixth embodiment can output video signals that comply with the plural respective video standards while reducing the number of pins of the extender-side connection terminal12. The extender10E according to the sixth embodiment can output, to a selected one of the plural video output terminals, a video signal that complies with the video standard corresponding to the selected video output terminal according to a preset priority order and a user manipulation(s) on a manipulation unit of the notebook PC20E. Furthermore, where, for example, a user has an electronic apparatus that cannot output a video signal that complies with the analog RGB standard and an analog-RGB-compatible external display device (102), the extender10E can mediate between the electronic apparatus and the analog-RGB-compatible external display device (102). The electronic apparatus and the analog-RGB-compatible external display device (102) can thus be used effectively instead of being rendered useless.

In connection with the extender10E according to the sixth embodiment, as in the case of the extender10according to the first embodiment, an arbitrary priority order other than the above described one, such as one in which a highest priority is given to connection to the HDMI socket14, can be set easily (refer toFIG. 4, for example). Where there are only two video output terminals as in the cases of the extender10A-10C according to the second to fourth embodiments, it suffices that only one multiplexer and hence only one GPIO be provided.

Like the extender10according to the first embodiment, the extender10E according to the sixth embodiment may be modified in such a manner that the switching module55is omitted and a video signal that is output from the GPU31is supplied equally to all the converters51-53.

For example, when the extender10according to the first embodiment and the extender10E according to the sixth embodiment are combined together, a final output destination socket can be determined taking into consideration both of settings that are input by a user by manipulating a manipulation unit of the notebook PC20E and connection statuses of the sockets13-15.

In this case, for example, a configuration is possible in which a first register is provided to show which of an output signal of the first GPIO34and an HPL_RGB signal should be given priority depending on their contents and whether the first multiplexer56should output a high-level switching control signal or a low-level switching control signal is determined according to a value of the first register and in which a second register is provided to show which of an output signal of the second GPIO35and an HPL_HDMI signal should be given priority depending on their contents and whether the second multiplexer57should output a high-level switching control signal or a low-level switching control signal is determined according to a value of the second register.