# Patent

## Title
Display device with USB connectivity

## Abstract

A display device (20) with USB connectivity connects with one or more USB devices (30) via one or more USB ports (207). The display device includes a power module (201), a display controller (202), a switching circuit (203), and an OR gate circuit (204). The display controller connects to a host (10), and is used to control the switching circuit according to a current status of the host. When the host is in a power-saving mode or a power off mode, the display controller controls the switching circuit to be on. Accordingly, the OR gate circuit electrically couples the power module to the USB ports. The display device thus powers the USB devices. If the host is in a normal mode, the display controller controls the switching circuit to be off. Accordingly, the OR gate circuit electrically couples the host to the USB ports. The host thus powers the USB devices.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to display devices, and particularly to a display device with built-in USB (Universal Serial Bus) ports, wherein via the USB ports the display device powers USB devices.
2. Description of the Related Art
A wide variety of computers have been configured with USB ports; for example, desktop, laptop, and notebook computers. Via the USB ports, the computers can communicate with external USB devices.
The power pins of the USB ports provide approximately +5V voltage. Recently, computers have been used to power or even charge external devices by utilizing the USB ports. The power supplied to an external device is typically obtained from a host of the computer. For example, via a USB port built into a display device of a computer, the computer can utilize the power from its host to power or even charge an external USB device.
However, when the power is supplied by the host, the power supply to the external device through the computer is practicable only when the host is in a normal working mode. Once the host enters into a power-saving mode or is powered off, the power supply to the external device is immediately cut off.
In addition, most display devices have their own power supply independent from the corresponding host. These display devices have their own potential ability to power external devices.
Therefore, there is a need for a display device with a USB port, whereby when a corresponding host is in a mode such as a power-saving mode or a power off mode, the display device can take over the power function from the host to power external USB devices.
SUMMARY OF THE INVENTION
To solve the above-mentioned and other problems, a display device with USB connectivity (hereinafter “the display device) is provided. The display device includes a power module and one or more USB ports. The power module has batteries embedded therein as a power source or is connected to an external power source to obtain power therefrom. The USB ports have power pins through which the power module powers or even charge external USB devices. The display device further includes a switching circuit which positioned between the power module and the USB ports, to establish or cut off a connection between the power module and the USB ports, and a controller which controls the to control the switching circuit to be on or be off, to establish or cut off the connection between the power module and the USB ports accordingly. The controller may be a display device which controls the switching circuit in accordance with a current status of a host, or a button, which controls the switching circuit in accordance with manually operations of a user.
Further, a computer system which includes a display device with USB connectivity is also provided. The computer system further includes a host. The host has a plurality of statuses, including a normal mode, a plurality of power-saving modes and a power off mode. The display device includes a power module, a display controller, a switching circuit, an OR gate circuit, and one or more USB ports. The USB ports have power pins, which selectively couple the power module or the host to external USB devices to power or charge the USB devices. The OR gate circuit selectively couples the power pins with the power module or with the host. The display device detects what status the host stands, and controls the switching circuit on or off to establish or cut off a connection between the power module and the USB ports, in accordance with the status of the host.
One of the advantages of the present invention is, in spite of what status the host may be in, whether a normal mode, a power-saving mode or a power off mode, after being connected to the display device via the USB ports of the display device, external USB devices are able to obtain power from the host or from the display device.
Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a display device with at least one built-in USB port, in accordance with the preferred embodiment of the present invention, together with a USB device which can interconnect with the display device via the USB port; and
FIG. 2 is a circuit diagram showing how the display device with the built-in USB port of FIG. 1 powers the USB device via the USB port, in accordance with the preferred embodiment of the present invention.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is an isometric view showing a display device with one or more built-in USB ports (hereinafter “the display device”) in accordance with a preferred embodiment of the present invention, together with a USB device which can connect with the display device via any one of the USB ports. The display device 20 may be a CRT (cathode ray tube), an LCD (liquid crystal display), or any other type of display apparatus known in the art. The USB ports 207 (only one is shown in FIG. 1) may be positioned in any suitable part of the display device 20, such as on a front panel or a rear panel of the display device 20. Appropriate positioning facilitates users in connecting the USB device 30 with the display device 20. In FIG. 1, an exemplary USB device 30 is shown as being a mobile phone.
The USB devices 30 may be coupled to the display device 20 directly, or via an intermediate apparatus. For example, the coupling may be via a hub which can expand the number of USB devices 30 to be connected to the display device 20 when needed, or via charging cables. The USB devices 30 are not to be construed as being limited to mobile phones, as illustrated in FIG. 1. On the contrary, the USB devices 30 may include all manner of various suitable electronic devices. Such electronic devices have one or more USB plugs 301, or are configured with charging cables or chargers that have a USB plug 301. Examples include mobile phones, MP3 (MPEG, audio layer 3) players, notebooks, PADs (Personal Digital Assistants), and so on.
The USB devices 30 may be equipped with one or more embedded secondary batteries if needed. When equipped with embedded secondary batteries, and connected with the display device 20, the USB devices 30 not only obtain power from the display device 20, but also synchronously charge the embedded secondary batteries via charging circuits thereof. Generally, a standard USB port 207 provides (5±5%)V voltage and 100 ̃500 mA current, which are sufficient to power and charge most USB devices 30 and their embedded secondary batteries. Otherwise, an additional adaptor is needed to adjust the voltage and current obtained from the USB port 207, in order to obtain a particular power level that is required by some specific USB devices 30.
FIG. 2 is a circuit diagram showing how the display device 20 powers a USB device 30 via a USB port 207, in accordance with the preferred embodiment of the present invention. The display device 20 interconnects with a host 10, which together constitute a computer system 1. The display device 20 includes at least one power module 201, a display controller 202, a switching circuit 203, an adapting apparatus 204, an OR gate circuit 205, and the USB port 207. The power module 201 powers all components of the display device 20. Further, when necessary, the power module 201 can power the USB device 30 in addition to powering the components of the display device 20. The power module 201 can supply the power from an intrinsic power source, (i.e., embedded batteries) or from an external power source.
The switching circuit 203 is series-connected between the power module 201 and the adapting apparatus 204. The switching circuit 203 has two input terminals and one output terminal. The input terminals are respectively connected to the power module 201 and the display controller 202, and the output terminal is connected to the adapting apparatus 204. The display controller 202 is connected to the host 10, and receives video signals from the host 10 via a video interface (not shown). The video interface can, for example, be a VGA (video graphics array) interface or a DVI (display visual interface) interface. Based on the state of video signals it receives, the display controller 202 determines what status the host stands in, and controls the switching circuit 203 on or off accordingly. Typically, the status can be a normal mode, a power-saving mode, or a power off mode. In the preferred embodiments, when the host 10 is detected to be in a power off mode or a power-saving mode, the display controller 202 controls the switching circuit 203 to be on, whereupon the power module 201 supplies power to the adapting apparatus 204 via the switch circuit 203. When the host 10 is detected to be in a normal mode, that is, the host 10 is in a normal working status, the display controller 202 controls the switch circuit 203 to be off, so as to stop the supply of power from the power module 201 to the adapting apparatus 204. The switching circuit 203 may include one or more transistors, or any other suitable switches that can switch on and off under the control of the display controller 202, whereby the supply of power from the power module 201 to the adapting apparatus 204 is either passed or blocked.
The adapting apparatus 204 is coupled to the USB port 207 via the OR gate circuit 205. The OR gate circuit 205 has two input terminals and one output terminal. The input terminals are respectively connected with the adapting apparatus 204 and the host 10. The output terminal is connected with a power pin (designated as 4d in FIG. 2) of the USB port 207. Via such a connection, the OR gate circuit 205 selectively couples the adapting apparatus 204 or the host 10 to the USB port 207. Accordingly, the source of power for the USB device 30 is either the power module 201 or the host 10. In the preferred embodiment, if the host 10 is powered off or in a power-saving mode, the display controller 202 controls the switching circuit 203 to conduct current. Then a first power path is established, which includes the power module 201, the switching circuit 203, the adapting apparatus 204, the OR gate circuit 205 and the USB port 207. If the host 10 is in a normal mode, the display controller 202 controls the switching circuit 203 to cut off. The first power path is correspondingly cut off current. Then a second power path is established, which includes the host 10 and the USB port 207 adopted to transmit power to the USB device 30. In the preferred embodiment, all of pins 4a, 4b, 4c (i.e., excluding the power pin 4d) of the USB port 207 are directly coupled to the host 10. These other pins, including one ground pin (designated as 4a) and two data pins (designated as 4b, and 4c), are directly coupled to the host 10. Thus the USB device 30 is able to exchange data with the host 10 when receiving power from the host 10.
The OR gate circuit 205 may include two parallel-connected diodes or transistors or any other suitable elements, such as a chip with a firmware program, which implement the function of selectively coupling the adapting apparatus 204 or the host 10 to the USB port 207. The adapting apparatus 204 includes a transformer (not shown), and converts the voltage and current from the power module 201 to match the USB port 207. Furthermore, the adapting apparatus 204 may also include a current-limiting apparatus to limit the current output, and a short-circuit protection circuit to protect the display device 20. In addition, instead of being placed between the switching circuit 203 and the OR gate circuit 205, in other embodiments, the adapting apparatus 204 may be positioned between the OR gate circuit 205 and the USB port 207, or in any other suitable place.
The display controller 202 controls the switching circuit 203 on or off in accordance with the current status of the host 10. In the preferred embodiment, the statuses of the host are defined pursuant to ACPI (Advanced Configuration and Power Interface) specifications, which were co-developed by Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba. The display controller 202 detects what status the host 10 stands in. If the host 10 is in any one of the power-saving modes, or in a power off mode, the display controller 202 controls the switching circuit 203 to be on. Meanwhile, the OR gate circuit 205 electrically couples the adapting apparatus to the USB port 207. The first power path conducts current, and the USB device 30 is powered or even charged by the power module 201. If the host 10 is in a normal mode, the display controller 202 controls the switching circuit 203 to be off. Accordingly, the OR gate circuit 205 electrically couples the host 10 to the USB port 207. The second power path conducts current, and the USB device 30 is powered or even charged by the host 10.
The above description illustrates that the switching circuit 203 is controlled by the display controller 202. However, in another embodiment, the switching circuit 203 can be manually controlled by a user via a button (not shown) installed on the display device 20. The button electrically controls the switching circuit 203 according to known technology. This gives the user the discretion to select the display device 20 as a power source of the USB device 30, even if the host 10 is in a normal mode.
It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of type and arrangement of components within the principles of the invention to the full extent indicated by general meaning of the terms in which the appended claims are expressed.

## Claims

1. A display device with USB (Universal Serial Bus) connectivity, comprising:
a power module; and
one or more USB ports, the USB ports having power pins, the power pins being for connecting the power module with one or more external USB devices to power or charge the USB devices;
a switching circuit, positioned between the power module and the USB ports, configured for connecting or disconnecting the USB ports from the power module;
a display controller configured for controlling the switching circuit to be on or off, to connect or disconnect the USB ports from the power module according to a current status of an associated host; and
an OR gate circuit selectively coupling the switching circuit or the associated host to the power pins of the USB ports;
wherein, the display controller controls the switching circuit to be on if the current status of the associated host is a power off mode or a power saving mode, whereupon the power module powers or charges the USB device; the display controller controls the switching circuit to be off if the current status of the associated host is a normal mode, whereupon the associated host is used to power or charge the USB device.

2. The display device with USB connectivity according to claim 1, further comprising a button installed on the display device, which can be manually controlled by a user to control the switching circuit.

3. The display device with USB connectivity according to claim 1, wherein the power module supplies the power from an external power source.

4. The display device with USB connectivity according to claim 1, further comprising an adapting apparatus to adjust the power from the power module to match the USB ports.

5. A computer system, comprising:
a host; and
a display device, comprising:
a power module;
one or more USB ports, the USB ports having power pins, the power pins being for selectively coupling the power module or the host to one or more external USB devices to power or charge the USB devices;
a switching circuit, positioned between the power module and the USB ports, configured for connecting or disconnecting the USB ports from the power module;
a display controller connected with the host and configured for controlling the switching circuit to be on or off, to connect or disconnect the USB ports from the power module according to a current status of the host; and
an OR gate circuit selectively coupling the power pins with the power module or with the host;
wherein the display controller controls the switching circuit to be on if the current status of the host is a power off mode or a power saving mode, whereupon the power module powers or charges the USB device; and the display controller controls the switching circuit to be off if the current status of the host is a normal mode, whereupon the host powers or charges the USB device.

6. The computer system according to claim 5, further comprising a button installed on the display device, which can be manually controlled by a user to control the switching circuit.