Network projector including a display signal control unit, and projector system including the network projector
AssigneeNEC Display Solutions, Ltd.
InventorsShuji Murayama, Masaki Kitagawa
Life of this patent
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Abstract
The present invention aims to provide a network projector which has a simple security function via a network. The network projector comprises a power source unit which supplies power to the network projector and a display signal control unit which, when confirming that a connection confirmation signal which is transmitted at a fixed period from a host computer via a network is not inputted for more than a predetermined time, outputs a supply stop signal to the power source unit indicating that the supply of power should be stopped.
Claims14
A network projector connected with a host computer via a wired local area network (LAN) comprising:
- a power source unit which supplies power to said network projector;
- and
- a display signal control unit which, when confirming that a connection confirmation signal, which is transmitted at a fixed period from the host computer via the wired LAN, is not inputted for more than a first predetermined time, outputs a supply stop signal to said power source unit indicating that a supply of power should be stopped,
- wherein said display signal control unit comprises:
- a timer which starts measurement of time when a measurement start signal indicating start of measurement of time is inputted, outputs a measurement end signal indicating that the measurement of time ends when the measured time reaches a second predetermined time, and is reset by input of a connection detection signal;
- a security control unit which outputs said supply stop signal to said power source unit when said measurement end signal is inputted;
- and
- a control unit which outputs said connection detection signal to said timer when detecting said connection confirmation signal, and outputs said measurement start signal to said timer when confirming that said connection confirmation signal has not been inputted within a time period during which the first predetermined time has elapsed after a cable for the wired LAN has been removed from said network projector.
A network projector connected with a host computer via a wired local area network(LAN), the network Projector comprising:
- an operation unit which accepts keyed-in input;
- a timer which starts measurement of time when a measurement start signal indicating start of measurement of time is inputted, outputs a measurement end signal indicating that the measurement of time ends when the measured time reaches a first predetermined time, and is reset by input of a connection detection signal;
- and
- a control unit which controls the operation of said network projector in accordance with an input signal indicating contents of an input to said operation unit, and outputs said connection detection signal to said timer when detecting a connection confirmation signal which is transmitted at a fixed period from the host computer via the wired LAN, outputs said measurement start signal to said timer when confirming that said connection confirmation signal has not been inputted within a time period during which a second predetermined time has elapsed after a cable for the wired LAN has been removed from the network projector, and does not accept said input signal when said measurement end signal is inputted.
A projector system comprising a network projector and a host computer connected via a wired local area network (LAN) wherein, said host computer comprises a first control unit which transmits a connection confirmation signal at a fixed period via the wired LAN, and
- wherein said network projector comprises:
- a power source unit which supplies power to the network projector;
- and
- a display signal control unit which, when confirming that said connection confirmation signal is not inputted for more than a first predetermined time, outputs a supply stop signal to the power source unit indicating that the supply of power should be stopped, and
- wherein said display signal control unit comprises:
- a timer which starts measurement of time when a measurement start signal indicating start of measurement of time is inputted, outputs a measurement end signal indicating that the measurement of time ends when the measured time reaches a second predetermined time and is reset by input of a connection detection signal;
- a security control unit which outputs said supply stop signal to said power source unit when said measurement end signal is inputted;
- and
- a second control unit which outputs said connection detection signal to said timer when detecting said connection confirmation signal, and outputs said measurement start signal to said timer when confirming that said connection confirmation signal has not been inputted within a time period during which the first predetermined time has elapsed after a cable for the wired LAN has been removed from said network projector.
Dependencies are inferred from the claim text.