Information processing apparatus, docking station, and external display control method
View Patent ↗According to one embodiment, an information processing apparatus includes a first logic circuit, a second logic circuit and a controller. The first logic circuit selectively supplies either the detection signal indicating the connection of the external display to a first connector or the detection signal indicating the connection of the external display to a second connector on an extension unit to the input/output port. The second logic circuit switches between supplying the detection signal to the input/output port and cutting off the detection signal to the input/output port. The controller controls the second logic circuit to cut off the supply of the detection signal to the input/output port for a first period when the extension unit is attached or detached.
1. An information processing apparatus comprising:
a first connector configured to connect to an external display;
a connecting portion configured to detachably connect to an extension unit comprising a second connector, the second connector configured to connect to the external display;
a display controller configured to assign an input/output port for receiving a supplied detection signal indicating a connection of the external display;
a first logic circuit configured to selectively supply either a detection signal indicating the connection of the external display to the first connector or a detection signal indicating the connection of the external display to the second connector from the extension unit through the connecting portion to the input/output port;
a second logic circuit between the input/output port and the first logic circuit and configured to switch between supplying the supplied detection signal output from the first logic circuit to the input/output port and cutting off the supplied detection signal output from the first logic circuit to the input/output port; and
a controller configured to control the second logic circuit to cut off the supply of the supplied detection signal output from the first logic circuit to the input/output port for a first period when the extension unit is attached or detached.
2. The apparatus of claim 1 , wherein the display controller is configured to recognize attachment or detachment of the external display when a value of a signal received by the input/output port changes and a state after the change continues for a second period less than or equal to the first period.
3. The apparatus of claim 2 , wherein the first logic circuit is configured to output the detection signal indicating the connection of the external display to the first connector when the extension unit is unattached, and to output the detection signal indicating the connection of the external display to the second connector when the extension unit is attached, based on a second detection signal indicating the attachment of the extension unit.
4. The apparatus of claim 3 , wherein the first logic circuit comprises a multiplexer.
5. The apparatus of claim 1 , wherein the first logic circuit is configured to output the detection signal indicating the connection of the external display to the first connector when the extension unit is unattached, and to output the detection signal indicating the connection of the external display to the second connector when the extension unit is attached, based on a second detection signal indicating the attachment of the extension unit.
6. The apparatus of claim 5 , wherein the first logic circuit comprises a multiplexer.
7. The apparatus of claim 1 , wherein the second logic circuit comprises an AND gate configured to output a signal indicating a logical product of a value of the supplied detection signal output from the first logic circuit and a value of a control signal output from the controller.
8. A control method of an information processing apparatus comprising a first connector configured to connect to an external display, a connecting portion configured to detachably connect to an extension unit comprising a second connector configured to connect to the external display, and a display controller configured to assign an input/output port for receiving a supplied detection signal indicating a connection of the external display, the method comprising:
selectively supplying, by a logic circuit, either a detection signal indicating the connection of the external display to the first connector or a detection signal indicating the connection of the external display to the second connector from the extension unit through the connecting portion to the input/output port; and
cutting off supply of the supplied detection signal indicating the connection of the external display to the input/output port for a first period when the extension unit is attached or detached.
9. The method of claim 8 , wherein the selectively supplying comprises:
supplying the detection signal indicating the connection of the external display to the first connector when the extension unit is unattached; and
supplying the detection signal indicating the connection of the external display to the second connector when the extension unit is attached.