Patent Application
20160249421
The present application claims benefit of Chinese patent application CN 201410856635.1, entitled “Backlight Module for Liquid Crystal Display and Liquid Crystal Display Device” and filed on Dec. 31, 2014, which is incorporated herein by reference.
The present disclosure relates to the technical field of liquid crystal display, and particularly to a backlight module for liquid crystal display device and a liquid crystal display device.
With the development of mobile technology, mobile phones have become indispensable communication tools in people's daily life. At present, Liquid Crystal Display (LCD) devices are most widely used as the screens of mobile phones. The liquid crystal display technology has undergone the development from black-and-white screen to colored screen, as well as from Twisted Nematic LCD (TN-LCD) to Thin Film Transistor LCD (TFT-LCD).
With the development of liquid crystal display technology, the size of the liquid crystal display devices that are used in mobile phones is becoming increasingly large, which renders that the power consumption of the liquid crystal display devices is becoming increasingly high. The backlight module is the main power consuming unit in the liquid crystal display device.
The structure of the backlight module in the prior art renders that the power consumption of the liquid crystal display screen accounts for 60 percent to 70 percent of the power consumption of the whole mobile phone. Since the limitation of the battery capacity of the mobile phone, the standby time thereof is greatly shortened due to the high power consumption of the liquid crystal display screen.
Therefore, a backlight module for liquid crystal display device with low power consumption is urgently needed.
The present disclosure aims to solve the technical problem of high power consumption of the backlight module of the liquid crystal display device in the prior art. In order to solve the aforesaid technical problem, the embodiment of the present disclosure firstly provides a backlight module for liquid crystal display device, comprising a light source circuit and a light guide plate. Said light source circuit comprises a control circuit, and a plurality of light-emitting units that are arranged on a lateral surface of said light guide plate and connected with said control circuit, each light-emitting unit being activated or deactivated by said control circuit. Said light guide plate is used for guiding light which enters from the lateral surface, so that the light exits from a front surface.
According to one embodiment of the present disclosure, a first end of each light-emitting unit is connected with a first end of a preset power source, and a second end thereof is connected with a corresponding end of said control circuit.
According to one embodiment of the present disclosure, each light-emitting unit comprises a light-emitting diode, a positive pole of said light-emitting diode being connected with the first end of the preset power source, and a negative pole thereof being connected with a corresponding end of said control circuit.
According to one embodiment of the present disclosure, said control circuit comprises a controllable switch, a first end of said controllable switch being connected with a second end of said preset power source, and each second end thereof being connected with a second end of a corresponding light-emitting unit respectively.
According to one embodiment of the present disclosure, said control circuit controls a time period during which said light-emitting unit is activated or deactivated through regulating a duty ratio of a control signal, so that brightness of said light-emitting unit is regulated.
According to one embodiment of the present disclosure, said light guide plate comprises a first surface and a second surface in parallel with each other, said first surface being provided with cylindrical protrusions that are parallel with one another, and said cylindrical protrusions or said second surface being provided with light guide apertures.
According to one embodiment of the present disclosure, said light guide plate comprises a first surface and a second surface in parallel with each other, said first surface and said second surface each being provided with cylindrical protrusions that are parallel with one another, and the cylindrical protrusions that are arranged on said first surface or said second surface being provided with light guide apertures.
According to one embodiment of the present disclosure, said light guide apertures are arranged along an axial direction of said cylindrical protrusions in a non-uniform manner.
According to one embodiment of the present disclosure, a space between two adjacent light guide apertures that are arranged in one cylindrical protrusion becomes nearer when a distance thereof from a first end of said cylindrical protrusion gets farther.
The present disclosure further provides a liquid crystal display device, which comprises a backlight module for liquid crystal display device as mentioned in any one of the above items.
Compared with the light source circuit of the backlight module in the prior art, in the light source circuit of the backlight module according to the present disclosure, the light-emitting units can be controlled separately. In this case, when it is not necessary to activate all light-emitting units according to actual needs of the liquid crystal display device, the light-emitting units which are necessary can be activated by the control circuit, while the light-emitting units which are not necessary can be deactivated by the control circuit. Since it is not necessary to activate all light-emitting units, the power consumption of the backlight module can be reduced effectively, and thus the life time of the electric devices (such as mobile phones) can be prolonged.
In addition, in the light source circuit according to the present disclosure, the brightness of the light source can also be regulated. Specifically, the time period during which the controllable switch is turned on or turned off can be regulated through regulating the duty ratio of the control signal, so that the time period during which the light-emitting diode is activated or deactivated can be regulated. During a certain time period, the longer the time during which the light-emitting diode is activated is, the brighter the light source looks; on the contrary, during a certain time period, the shorter the time during which the light-emitting diode is activated is, the darker the light source looks. In this manner, the brightness of the light source can be regulated.
According to the present disclosure, the surface of the light guide plate is provided with cylindrical protrusions that are parallel with one another, which enable the light to be in a relatively convergent state when transmitting in the light guide plate. Therefore, compared with the light guide plate in the prior art, the light guide plate provided by the present disclosure has a better light converging effect. Thus, the crosstalk of the light in the light guide plate can be reduced significantly.
In the light guide plate provided by the present disclosure, the light guide apertures are arranged in a non-uniform manner in order to guarantee the uniformity of the light that exits from the surface of the light guide plate. Specifically, in each cylindrical protrusion that is provided with light guide apertures, a space between two adjacent light guide apertures that are arranged in the cylindrical protrusion becomes nearer (i.e., the light guide apertures are distributed in a denser manner) when a distance between the light guide apertures and a first end of the cylindrical protrusion (i.e., the end near to the light-emitting units) gets farther.
The light that exits from the light guide apertures near to the light-emitting units is relatively more, but the light guide apertures are distributed in a sparse manner at this region. By contrast, the light that exits from the light guide apertures far from the light-emitting units is relatively less, but the light guide apertures are distributed in a dense manner at this region. In this manner, the light that exits from each region of the light guide plate can be kept balanced, and thus the uniformity of the light that exits from the surface of the light guide plate can be ensured.
Other features and advantages of the present disclosure will be further explained in the following description, and partially become self-evident therefrom, or be understood through the embodiments of the present disclosure. The objectives and advantages of the present disclosure will be achieved through the structure specifically pointed out in the description, claims, and the accompanying drawings.
The drawings necessary for explaining the embodiments or the prior art are introduced briefly below to illustrate the technical solutions of the embodiments of the present disclosure or the prior art more clearly.
The present disclosure will be explained in details with reference to the embodiments and the accompanying drawings, whereby it can be fully understood how to solve the technical problem by the technical means according to the present disclosure and achieve the technical effects thereof, and thus the technical solution according to the present disclosure can be implemented. It should be noted that, as long as there is no structural conflict, all the technical features mentioned in all the embodiments may be combined together in any manner, and the technical solutions obtained in this manner all fall within the scope of the present disclosure.
Many specific details are illustrated hereinafter for providing a thorough understanding of the embodiments of the present disclosure. However, it is obvious for those skilled in the art that, the present disclosure can be implemented in other methods in addition to the details or specifics described herein.
In order to solve the technical problem of high power consumption of the backlight module of the liquid crystal display device in the prior art, the present embodiment provides a backlight module of a liquid crystal display device, in which each light-emitting unit can be activated or deactivated separately. The backlight module comprises a light source circuit and a light guide plate.
As shown in
According to the present embodiment, a first end of each light-emitting unit 201 is connected with a first end of a preset power source, and a second end thereof is connected with a corresponding end of the control circuit 202. As shown in
According to the present embodiment, the control circuit 202 comprises a controllable switch, which comprises a first end and a plurality of second ends. The first end of the controllable switch is connected with a second end of the preset power source (the negative pole of the preset power source, i.e., the end K), and each second end thereof is connected with a negative pole of a corresponding light-emitting diode respectively.
When the light-emitting diode D1 needs to be activated, a connection between the end B1 and the end K would be turned on by the controllable switch. At this time, a voltage across the two ends of the light-emitting diode D1 reaches an operating voltage thereof, and thus the light-emitting diode D1 can emit light. Since the connections between each of the ends that are connected with the light-emitting diodes (i.e., the ends B1 to Bn) and the end K can be turned on or turned off by the controllable switch separately, each light-emitting diode can be activated or deactivated by the controllable switch separately as well. That is, one light-emitting diode or a plurality of light-emitting diodes can be activated or deactivated by the controllable switch at the same time.
Of course, according to other embodiments of the present disclosure, the control circuit can also be arranged between the light-emitting units and the positive pole of the preset power source. The first end of each light-emitting unit is connected with the control circuit, and the second end thereof is connected with the negative pole of the preset power source. The present disclosure is not limited by this.
Compared with the light source circuit of the backlight module in the prior art, in the light source circuit according to the present embodiment, the light-emitting units can be controlled separately. In this case, when it is not necessary to activate all light-emitting units according to actual needs of the liquid crystal display device, the light-emitting units which are necessary can be activated by the control circuit, while the light-emitting units which are not necessary can be deactivated by the control circuit. Since it is not necessary to activate all light-emitting units, the power consumption of the backlight module can be reduced effectively (for example, compared with the light source circuit in the prior art, the power consumption of the light source circuit provided by the present embodiment can be reduced by 40 percent), and thus the life time of the electric devices (such as mobile phones) can be prolonged.
In addition, in the light source circuit according to the present embodiment, the brightness of the light source can be regulated. Specifically, according to the present embodiment, the time period during which the light-emitting diode is activated or deactivated can be regulated by the controllable switch through regulating the duty ratio of the control signal. During a certain time period, the longer the time during which the light-emitting diode is activated is, the brighter the light source looks; on the contrary, during a certain time period, the shorter the time during which the light-emitting diode is activated is, the darker the light source looks. In this manner, the brightness of the light source can be regulated.
It should be noted that, according to other embodiments of the present disclosure, the light-emitting units and/or the control circuit can also be realized with other reasonable forms of circuit, and the present disclosure is not limited by this. For example, according to one embodiment of the present disclosure, the control circuit can be realized with Field Programmable Gate Array (FPGA) circuit. The FPGA circuit enables the switching circuit to have a higher response speed, so that the light-emitting units can be controlled by the control circuit in a timelier and more accurate manner.
In order to solve the aforesaid technical problem, the present embodiment further provides a light guide plate which can play the role of converging light effectively.
According to the present embodiment, the light guide plate is made of engineering plastic. During manufacturing process, the engineering plastic is firstly melted into liquid state by a melting furnace, and then the engineering plastic in liquid state is transferred to a rolling part through a T-head. There is a certain distance between the T-head and the rolling part. The engineering plastic in liquid state, after being output by the T-head, is cooled gradually during dropping process. The engineering plastic is not cooled completely when reaching the rolling part, and thus the rolling can be performed conveniently.
According to the present embodiment, the rolling part of the device for manufacturing the light guide plate comprises a first roller and a second roller which rotate in cooperation with each other. Since the cylindrical protrusions need to be formed on the first surface and the second surface of the light guide plate, according to the present embodiment, the first roller and the second roller are both provided with protrusions. The engineering plastic, which is transferred from the T-head and is not cooled completely, can be rolled by the first roller and the second roller, so that the structure of the light guide plate as shown in
According to different embodiments of the present disclosure, the protrusions of the roller can be a plurality of circumferential protrusions arranged on a surface of a rolling axle, or can be a plurality of axial cylindrical protrusions arranged on the surface of the rolling axle. According to the present embodiment, the protrusions that are arranged on the first roller and the second roller are circumferential protrusions. This is because, when the engineering plastic is rolled by the roller with circumferential protrusions, a closed space would not be formed between the protrusions and the rolling axle, so that the air in the engineering plastic can be extruded effectively. In this case, the light guide plate rolled therein can have a more uniform structure, the impurities thereof are much less, so that the desirable light-guiding performance of the light guide plate can be guaranteed.
The engineering plastic, after being rolled by the rolling part, is transferred to a transferring part, so that the transferring part can transfer the light guide plate that comes from the rolling part to the following parts of the production line. Since the light guide plate that comes from the rolling part is not cooled completely, the process during which the light guide plate is transferred on the transferring part is the process during which the engineering plastic is cooled. In order to guarantee that the light guide plate is not damaged during this process, according to the present embodiment, the transferring part consists of a plurality of elastic wheels that are arranged side by side with one another so as to support and transfer the light guide plate that comes from the rolling part.
During the process of the light guide plate rolled therein being transferred on the transferring part, a defect detection part of the device would perform defect detection on the light guide plate, so that the structural integrity and the reliability of the light guide plate can be ensured. In addition, since the light guide plate manufactured therein has cylindrical protrusions, dust would accumulate easily on the surface among the cylindrical protrusions. Therefore, according to the present embodiment, the device for manufacturing the light guide plate, after performing defect detection on the light guide plate, can coat the light guide plate with films, so that the upper surface and the lower surface of the light guide plate are coated with protection films respectively. The protection films not only can effectively guarantee the light guide plate to be clean and dustless, but also can protect the surfaces of the light guide plate from being damaged. According to the present embodiment, the protection films that are coated on the light guide plate are adhesive films. Of course, according to other embodiments of the present disclosure, the light guide plate can also be coated with films of other reasonable forms.
At last, the light guide plate, after being coated with films, is cut, so that the light guide plate with required size can be obtained.
In order to present the light converging effect of the light guide plate as shown in
As shown in
Since one of the roles played by the light guide plate is converting the side light source into the surface light source, the light inside the light guide plate should exit from the surface thereof. However, the light transmits in a total reflection manner inside the light guide plate, and the total reflection structure of the light guide plate should be destroyed so that the light can exit from the surface of the light guide plate.
As shown in
The light-emitting units are arranged on the lateral surface of the light guide plate, and the light which enters into the light guide plate would exit from the light guide apertures. Therefore, the larger the distance between the light guide aperture and the light-emitting units is, the less light would exit therefrom. In the light guide plate provided by the present embodiment, the light guide apertures are arranged in a non-uniform manner in order to guarantee the uniformity of the light that exits from the surface of the light guide plate. Specifically, in each cylindrical protrusion that is provided with light guide apertures, a space between two adjacent light guide apertures that are arranged in the cylindrical protrusion becomes nearer (i.e., the light guide apertures are distributed in a denser manner) when a distance thereof from a first end of the cylindrical protrusion (i.e., the end near to the light-emitting units) gets farther.
The light that exits from the light guide apertures near to the light-emitting units is relatively more, but the light guide apertures are distributed in a sparse manner at this region. By contrast, the light that exits from the light guide apertures far from the light-emitting units is relatively less, but the light guide apertures are distributed in a dense manner at this region. In this manner, the light that exits from each region of the light guide plate can be kept balanced, and thus the uniformity of the light that exits from the surface of the light guide plate can be ensured.
It should be noted that, according to other embodiments of the present disclosure, the uniformity of the light that exits from the surface of the light guide plate can be ensured through other reasonable methods. The present disclosure is not limited by the aforesaid method.
According to another embodiment of the present disclosure, the light guide plate can have a structure as shown in
According to a third embodiment of the present disclosure, the light guide plate can have a structure as shown in
According to a fourth embodiment of the present disclosure, the light guide plate can have a structure as shown in
Compared with the light source circuit of the backlight module in the prior art, in the light source circuit of the backlight module according to the present disclosure, the light-emitting units can be controlled separately. In this case, when it is not necessary to activate all light-emitting units according to actual needs of the liquid crystal display device, the light-emitting units which are necessary can be activated by the control circuit, while the light-emitting units which are not necessary can be deactivated by the control circuit. Since it is not necessary to activate all light-emitting units, the power consumption of the backlight module can be reduced effectively, and thus the life time of the electric devices can be prolonged.
In addition, in the light source circuit according to the present disclosure, the brightness of the light source can also be regulated. Specifically, the time period during which the light-emitting diode is activated or deactivated can be regulated by the controllable switch through regulating the duty ratio of the control signal. During a certain time period, the longer the time during which the light-emitting diode is activated is, the brighter the light source looks; on the contrary, during a certain time period, the shorter the time during which the light-emitting diode is activated is, the darker the light source looks. In this manner, the brightness of the light source can be regulated.
According to the present disclosure, the surface of the light guide plate is provided with cylindrical protrusions that are parallel with one another, which enable the light to be in a relatively convergent state when transmitting in the light guide plate. Therefore, compared with the light guide plate in the prior art, the light guide plate provided by the present disclosure has a better light converging effect. Thus, the crosstalk of the light in the light guide plate can be reduced significantly.
In the light guide plate provided by the present disclosure, the light guide apertures are arranged in a non-uniform manner in order to guarantee the uniformity of the light that exits from the surface of the light guide plate. Specifically, in each cylindrical protrusion that is provided with light guide apertures, a space between two adjacent light guide apertures that are arranged in the cylindrical protrusion becomes nearer (i.e., the light guide apertures are distributed in a denser manner) when a distance between the light guide apertures and a first end of the cylindrical protrusion (i.e., the end near to the light-emitting units) gets farther.
The light that exits from the light guide apertures near to the light-emitting units is relatively more, but the light guide apertures are distributed in a sparse manner at this region. By contrast, the light that exits from the light guide apertures far from the light-emitting units is relatively less, but the light guide apertures are distributed in a dense manner at this region. In this manner, the light that exits from each region of the light guide plate can be kept balanced, and thus the uniformity of the light that exits from the surface of the light guide plate can be ensured.
It could be understood that, the embodiments disclosed herein are not limited by the specific structures, treatment steps or materials disclosed herein, but incorporate the equivalent substitutes of these features which are comprehensible to those skilled in the art. It could be also understood that, the terms used herein are used for describing the specific embodiments, not for limiting them.
The phrases “one embodiment” or “embodiments” referred to herein mean that the descriptions of specific features, structures and characteristics in combination with the embodiments are included in at least one embodiment of the present disclosure. Therefore, the phrases “one embodiment” or “embodiments” appeared in different parts of the whole description do not necessarily refer to the same embodiment.
For the purpose of convenience, a plurality of items, structural units, component units and/or materials used herein can be listed in a common list. However, the list shall be understood in a way that each element thereof represents an only and unique member. Therefore, when there is no other explanation, none of members of the list can be understood as an actual equivalent of other members in the same list only based on the fact that they appear in the same list. In addition, the embodiments and examples of the present disclosure can be explained with reference to the substitutes of each of the components. It could be understood that, the embodiments, examples and substitutes herein shall not be interpreted as the equivalents of one another, but shall be considered as separate and independent representatives of the present disclosure.
In addition, the features, structures and characteristics described herein can be combined with one another in any other suitable way in one embodiment or a plurality of embodiments. The specific details, such as lengths, widths and shapes, described herein are used for providing a comprehensive understanding of the embodiments of the present disclosure. However, it is understandable for those skilled in the art that, the present disclosure may be implemented in other ways different from the specific details specified herein, or may be implemented in other methods, components and materials. The structures, materials and operations known to all are not shown or described in the examples to avoid blurring various aspects of the present disclosure.
The embodiments are described hereinabove to interpret the principles of the present disclosure in one application or a plurality of applications. However, a person skilled in the art, without departing from the principles and thoughts of the present disclosure, can make various modifications to the forms, usages and details of the embodiments of the present disclosure without any creative work. Therefore, the protection scope of the present disclosure shall be determined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201410856635.1 | Dec 2014 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2015/071212 | 1/21/2015 | WO | 00 |
