TWI404032B - Liquid crystal display device connecting external image signal source - Google Patents

Abstract

The present invention relates to a liquid crystal display device connecting an external image signal source. The liquid crystal display device connecting an external image signal source includes a power board, a control circuit, and a liquid crystal panel. The power board supplies a working voltage for the control circuit. When the liquid crystal display device works in an energy saving state, the control circuit controls the power board to stop working, and the image signal source supplies a working voltage for the control circuit.

Description

Liquid crystal display device with external image signal source

The invention relates to a liquid crystal display device with an external image signal source.

Liquid crystal display devices have been widely used in various modern information devices such as displays, televisions, mobile phones, and digital products due to their advantages of light weight, low power consumption, low radiation, and portability.

Please refer to FIG. 1 , which is a schematic structural diagram of a liquid crystal display device with a prior art external image signal source. The liquid crystal display device 1 includes a power board 11, a control circuit 12, and a liquid crystal panel 13. The power board 11 provides an operating voltage to the control circuit 12. The image signal source 14 provides an image signal to the liquid crystal panel 13 by the control circuit 12.

When the image signal source 14 has no image signal output for a certain period of time, the control circuit 12 controls the liquid crystal display device 1 to be in the power saving mode, and the power board 11 provides the control circuit 12 with the working voltage required for the power saving mode. .

Although the operating voltage of the control circuit 12 is relatively low in the power saving mode, the power consumption of the liquid crystal display device 1 is reduced, but the power consumption of the power supply panel 11 itself is relatively high, resulting in power consumption of the liquid crystal display device 1. Still higher.

In view of this, it is necessary to provide a liquid crystal display device with lower power consumption.

A liquid crystal display device with an external image signal source includes a power board, a control circuit and a liquid crystal panel. The power board is used to provide an operating voltage for the control circuit. The image signal source provides an image signal to the liquid crystal panel by the control circuit. When the liquid crystal display device is in the power saving mode, the control circuit sends a control signal to control the power board to stop working, and the image signal source is used. The operating voltage is supplied to the control circuit.

A liquid crystal display device with an external image signal source includes a power board, a control circuit and a liquid crystal panel. The power board provides an operating voltage for the control circuit. The image signal source includes a power output end and a signal output end, and the image signal outputted by the signal output end is provided to the liquid crystal panel via the control circuit. When the liquid crystal display device is in the power saving mode, the power output terminal of the image signal source supplies the operating voltage to the control circuit.

Compared with the prior art, in the liquid crystal display device of the external image signal source of the present invention, when the liquid crystal display device is in the power saving mode, the image signal source supplies the operating voltage to the control circuit, thereby reducing the power board. The power consumption is such that the power consumption of the liquid crystal display device is low.

Please refer to FIG. 2 , which is a schematic structural diagram of a first embodiment of a liquid crystal display device with an external image signal source according to the present invention. The liquid crystal display device 2 includes an AC power source 20, a power board 21, a control circuit 22, a liquid crystal panel 23, and a first switch circuit 25. The power board 21 provides an operating voltage to the control circuit 22.

The image signal source 24 is a device that can generate an image signal, such as a computer host. The image signal source 24 includes a signal output terminal 241 and a power source output terminal 242. The image signal source 24 outputs an image signal through the signal output terminal 241. The image signal is processed by the control circuit 22 and then supplied to the liquid crystal panel 23 for display. The power output 242 provides an operating voltage to the control circuit 22 by the first switching circuit 25. The control circuit 22 controls the first switching circuit 25 to be turned on or off.

The power board 21 includes an input end 211 and a controller 212. The alternating current The source 20 is electrically connected to the input terminal 211 to provide an operating voltage for the power board 21. The controller 212 includes a feedback control terminal 213. The control circuit 22 controls the controller 212 to operate or stop working by the feedback control terminal 213, thereby controlling whether the power supply board 21 supplies the operating voltage to the control circuit 22. When the feedback control terminal 213 receives the high level signal, the controller 212 stops operating.

Please refer to FIG. 3 , which is a schematic structural diagram of the first switch circuit 25 in FIG. 2 . The first switch circuit 25 includes a power input terminal 251, a control signal input terminal 252, an output terminal 253, a first capacitor 254, a first bias resistor 255, a voltage dividing resistor 256, a transistor 257, A second capacitor 258, a second bias resistor 259 and a bipolar transistor 260. The transistor 257 is a PNP type field effect transistor. The bipolar transistor 260 is an NPN type bipolar transistor. The first capacitor 254 and the second capacitor 258 act as filtering.

The power input terminal 251 is electrically connected to the power output terminal 242 while being grounded via the first capacitor 254. The gate of the transistor 257 is connected in series with the voltage dividing resistor 256, and is electrically connected to the collector of the bipolar transistor 260. The source is electrically connected to the power input terminal 251 and connected in series with the first bias resistor 255. The collector of the bipolar transistor 260 is electrically connected, and its drain is connected to the control circuit 22 as the output terminal 253. The control signal input terminal 252 is electrically connected to the control circuit 22. The base of the bipolar transistor 260 is electrically connected to the control signal input terminal 252, and the emitter of the bipolar transistor 260 is grounded. The base of the bipolar transistor 260 is grounded via a filter bias circuit composed of the second bias resistor 259 and the second capacitor 258 in parallel.

When the signal output terminal 241 has no image signal output for a certain period of time, the control circuit 22 controls the liquid crystal display device 2 to be in the power saving mode. At the same time, the control circuit 22 sends a high level control signal to the feedback control terminal 213 and the Control signal input 252. At this time, the controller 212 receives the feedback control signal of the high level to stop working, so that the power board 21 stops working. The high-level control signal received by the control signal input terminal 252 also causes the base of the bipolar transistor 260 to be at a high level, and the bipolar transistor 260 is turned on, so that the gate of the transistor 257 is grounded, so the electricity The crystal 257 is turned on, and the operating voltage outputted from the power output terminal 242 is outputted to the control circuit 22 via the power input terminal 251 and the transistor 257, so that the control circuit 22 is in the power saving mode. Like the signal source 24, the operating voltage is obtained. When the signal output terminal 241 normally outputs an image signal, the liquid crystal display device 2 is in a normal operation mode, the transistor 257 is turned off, and the AC power source 20 supplies power to the control circuit 22 by the power source board 21.

Compared with the prior art, in the liquid crystal display device 2 of the external image signal source of the present embodiment, when the liquid crystal display device 2 is in the power saving mode, the control circuit 22 sends a control signal to the controller 213, so that the controller The 213 is stopped, so that the power board 21 is stopped. At the same time, the control circuit 22 sends a control signal to turn on the first switch circuit 25. The image signal source 24 externally connected to the liquid crystal display device 2 supplies the control circuit 22 with an operating voltage. Since the power supply board 21 no longer supplies the operating voltage to the control circuit 21 in the power saving mode, power consumption can be reduced, and thus the liquid crystal display device 2 consumes less power.

Please refer to FIG. 4 , which is a schematic structural diagram of a second embodiment of a liquid crystal display device with an external image signal source according to the present invention. The liquid crystal display device 3 has substantially the same structure as the liquid crystal display device 2, except that a second switch circuit 36 is disposed between the input end 311 of the liquid crystal display device 3 and the AC power source 30, and the controller 312 has no feedback control terminal. That is, the control circuit 32 no longer controls the controller 312. The second switching circuit 36 is a relay.

The AC power source 30 provides AC power to the input terminal 311 via the second switch circuit 36.

When the liquid crystal display device 3 is in the power saving mode, the control circuit 32 sends a control signal to the first switch circuit 35 and the second switch circuit 36 to control the first switch circuit 35 to be in an on state. The second switch circuit 36 is in the off state. The AC power supply 30 cannot supply AC power to the input terminal 311 by the second switch circuit 36. The power supply board 31 stops operating, and the operating voltage outputted by the power output terminal 342 is supplied to the control circuit 32 via the first switch circuit 35. When the signal output terminal 341 normally outputs an image signal, the liquid crystal display device 3 is in a normal operation mode, the second switch circuit 36 is closed, and the AC power source 30 supplies power to the power board 31 by the second switch circuit 36. The power board 31 supplies power to the control circuit 32.

In the liquid crystal display device 3 of the second embodiment, the AC power supply 30 cannot be output to the power supply board 31 by turning off the second switching circuit 36 in the power saving mode, that is, the power supply board 31 is completely de-energized. The power consumption of the liquid crystal display device 3 can be further reduced as compared with the case where the power source board 21 of the first embodiment is still connected to the AC power source 20 in the power saving mode.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above-mentioned embodiments are merely preferred embodiments of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in light of the spirit of the present invention are It should be covered by the following patent application.

2, 3‧‧‧ liquid crystal display device

20, 30‧‧‧ AC power supply

21, 31‧‧‧ power board

211, 311‧‧‧ input

212, 312‧‧ ‧ controller

213‧‧‧Feedback console

22, 32‧‧‧ control circuit

23‧‧‧LCD panel

24, 34‧‧‧ image signal source

241, 341‧‧‧ signal output

242, 342‧‧‧ power output

25, 35‧‧‧ first switch circuit

251‧‧‧Power input

252‧‧‧Control signal input

253‧‧‧ Output

254‧‧‧first capacitor

255‧‧‧First bias resistor

256‧‧‧voltage resistor

257‧‧‧Optoelectronics

258‧‧‧second capacitor

259‧‧‧Second bias resistor

260‧‧‧ bipolar transistor

36‧‧‧Second switch circuit

1 is a schematic structural view of a liquid crystal display device of a prior art external image signal source.

2 is a schematic structural view of a first embodiment of a liquid crystal display device with an external image signal source according to the present invention.

3 is a schematic structural view of a first switching circuit of the liquid crystal display device shown in FIG. 2.

4 is a schematic structural view of a second embodiment of a liquid crystal display device with an external image signal source according to the present invention.

2‧‧‧Liquid crystal display device

20‧‧‧AC power supply

21‧‧‧Power board

211‧‧‧ input

212‧‧‧ Controller

213‧‧‧Feedback console

22‧‧‧Control circuit

23‧‧‧LCD panel

24‧‧‧Image source

241‧‧‧ signal output

242‧‧‧Power output

25‧‧‧First switch circuit

Claims (8)

A liquid crystal display device with an external image signal source, comprising: a power board comprising a controller; a control circuit; and a liquid crystal panel; wherein the power board is configured to provide a working voltage for the control circuit, The image signal source provides an image signal to the liquid crystal panel by the control circuit. When the liquid crystal display device is in the power saving mode, the control circuit stops the operation by controlling the controller, thereby controlling the power board to stop working. The image signal source provides an operating voltage for the control circuit. The liquid crystal display device of the image signal source of claim 1, wherein the liquid crystal display device further comprises a first switch circuit, wherein the first switch circuit is connected to the control circuit and the image signal source When the control circuit controls the first switch circuit to be turned on, the image signal source provides an operating voltage to the control circuit via the first switch circuit. The liquid crystal display device further includes an AC power source, and the power board includes an input terminal, wherein the AC power source is the input terminal The power board provides operating voltage. The liquid crystal display device of the external image signal source as described in claim 3, wherein the liquid crystal display device further includes a second switch circuit connected between the AC power source and the input terminal When the control circuit controls the second switch circuit to be disconnected, the power board stops working. A liquid crystal display device with an external image signal source, comprising: a power board comprising a controller; a control circuit; and a liquid crystal panel; wherein the power board provides a working voltage for the control circuit, the liquid crystal display An image signal source is externally connected to the device, the image signal source includes a signal output end and a power output end, and the image signal outputted by the signal output end is provided to the liquid crystal panel through the control circuit, when the liquid crystal display device is in the province In the electrical mode, the control circuit controls the controller to stop working, thereby controlling the power board to stop working, and the power output terminal of the image signal source supplies the operating voltage to the control circuit. The liquid crystal display device of the image signal source of claim 5, wherein the liquid crystal display device further comprises a first switch circuit, wherein the first switch circuit is connected to the control circuit and the power output end When the control circuit controls the first switch circuit to be turned on, the power output terminal provides an operating voltage to the control circuit via the first switch circuit. The liquid crystal display device of the image source of claim 5, wherein the liquid crystal display device further comprises an AC power source, the power board includes an input, and the AC power source is the input terminal The power board provides operating voltage. The liquid crystal display device of the image source of claim 7, wherein the liquid crystal display device further comprises a second switch circuit, the second switch circuit is connected between the AC power source and the input end The control circuit controls the power strip when the second switch circuit is disconnected stop working.