KR20030082788A - Assembly of plasma display panel - Google Patents

Abstract

PURPOSE: A plasma display panel assembly is provided to prevent the vibration and the noise from circuits of a printed circuit board or the outside by installing a noise prevention portion on the printed circuit board. CONSTITUTION: A plasma display panel assembly includes a plasma display panel(21), a chassis(23), and one or more printed circuit board(24). The plasma display panel(21) is used for forming a picture image by using a discharge phenomenon. The chassis(23) is adhered on a backside of the plasma display panel(21) by using an adhesive sheet(22) in order to discharge the heat from the plasma display panel(21). The printed circuit board(24) includes a noise prevention portion in order to prevent the vibration and the noise from a driving circuit. The printed circuit board(24) is installed at a predetermined position apart from a backside of the chassis(23). The noise prevention portion is formed with one or more bent portions(26) formed on the printed circuit board(24).

Description

Plasma display panel assembly

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel assembly, and more particularly, to a plasma display panel assembly in which a circuit board is improved to prevent transmission of noise or vibration generated from elements on the circuit board.

Conventional discharge devices have at least a pair of electrodes, which generate a discharge when a voltage is applied to the electrodes. Examples of such a discharge device include discharge lamps such as fluorescent lamps, gas laser generators, and plasma display panels.

The plasma display panel is a device that displays characters or graphics using light emitted from the plasma generated during gas discharge, and is also called a gas discharge display device because it is a display device using a gas discharge phenomenon.

Plasma display panel is a direct current type that the electrode used to apply voltage applied from outside to make plasma is directly exposed to plasma so that the conduction current flows directly through the electrode and the electrode is covered with dielectric so that the displacement current does not flow directly. It is divided into AC type.

In addition, according to the electrode structure of the discharge cell, it is classified into a counter discharge type, a surface discharge type, a barrier discharge type, and the like. In the case of directly using the visible light emitted from the discharge gas, it is mostly used in a monochromatic display plasma display panel element, and neon is a typical example. There is a display panel using orange color from gas, and when color display is required, ultraviolet light from discharge gas such as krypton or xenon excites red (R), green (G), and blue (B) phosphors. Will be used.

Plasma display panels have excellent display performance such as display capacity, brightness, contrast, and viewing angle, and are thus positioned as next-generation display panels that approach the performance of cathode ray tubes.

1 is an exploded perspective view of a plasma display panel assembly according to the prior art.

As shown, the back surface of the plasma display panel 11 forming an image by discharge is adhered to the adhesive sheet 12 having thermal conductivity and attached to the front surface of the chassis 13 for heat dissipation on the plate. On the rear surface of the chassis 13, a circuit board 14 provided with circuit elements for driving the plasma display panel is provided to be spaced apart by a predetermined interval through the connection device 15. The plasma display panel assembly 10 thus formed is mounted in a space formed by the cabinet 16 and the back cover 17. In addition, the support 18 is connected to the lower end of the chassis (13).

When the plasma display panel is driven, its temperature rises due to plasma discharge. The heat is transferred to the chassis 13 through the adhesive sheet 12 and discharged to the outside. The heat dissipation is important in the plasma display panel assembly because heat may adversely affect a phosphor, an electrode, an electromagnetic wave shielding film, and the like, and thus, it is necessary to suppress the temperature below a predetermined temperature. For efficient heat dissipation, aluminum having good thermal conductivity is mainly used as a material of the chassis 13, the cabinet 16, the back cover 17, the support 18, and the like.

On the other hand, the noise generated by the plasma display panel assembly 10 is generated by the vibration caused by the discharge and the circuit drive is transmitted to the mechanism such as the chassis 13, conventionally reduced noise of the plasma display panel assembly 10 In order to prevent the noise from leaking out of the plasma display panel assembly by surrounding the back cover 17. However, this method is disadvantageous in solving the heat dissipation problem of the above-described plasma display panel assembly, and therefore, noise reduction using the back cover 17 is limited.

In order to solve the noise problem, a technical configuration for preventing unnecessary noise generated from a circuit by a back cover is disclosed in Korean Patent Laid-Open Publication No. 2001-0087381. However, such a configuration, as described above, lowers the heat dissipation effect of the plasma display panel, and thus, there is still a problem that there is a limit in noise reduction.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above problems, and to provide a plasma display panel assembly capable of reducing noise.

1 is an exploded perspective view of a conventional plasma display panel assembly;

2 is an exploded perspective view of a plasma display panel assembly according to the present invention;

3 is a perspective view showing only a circuit board,

4 is a perspective view showing another type of circuit board,

5 is a plan view showing a circuit board on which circuit elements are not mounted;

6 is a plan view showing another circuit board on which no circuit element is mounted;

7 is a plan view showing a circuit board on which circuit elements are mounted.

<Brief description of symbols for the main parts of the drawings>

20; Plasma display panel assembly 11,21; Plasma display panel

22; Adhesive sheets 13,23; Chassis

14,24,31,41; Circuit boards 26,34,44; Cutout

33,43; Circuit elements 15,25; Connecting device

In order to achieve the above object, the present invention provides a plasma display panel for forming an image by discharge, a chassis attached to a rear surface of the plasma display panel by an adhesive sheet and dissipating heat generated from the plasma display panel; Plasma display panel assembly comprising at least one circuit board mounted via a connecting device spaced apart from the rear surface of the circuit board and having noise blocking means for blocking the propagation of vibration and noise generated from the elements of the driving circuit. to provide.

According to one feature of the invention, the noise blocking means comprises at least one cutout formed on a circuit board.

According to another feature of the invention, the cutout is formed in a straight or curved in the propagation path of the noise and vibration on the circuit board.

According to another feature of the invention, the cutout is curved or curved around the connecting device to partition the circuit board into a fixed region and a flexible region.

According to another feature of the invention, the cutout is made discontinuously.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 illustrates an embodiment of a plasma display panel assembly according to the present invention.

As shown, the back surface of the plasma display panel 21 which forms an image by discharge is adhered to the adhesive sheet 22 having thermal conductivity and attached to the front surface of the chassis 23 for heat dissipation on the plate. The adhesive sheet 22 is composed of a heat radiation sheet 22a and a double-sided tape 22b, and the heat radiation sheet 22a is also adhesive. On the rear surface of the chassis 23, a circuit board 24 provided with circuit elements for driving the plasma display panel is provided to be spaced apart by a predetermined interval through the connection device 25. The plasma display panel assembly 20 thus formed is mounted in a space formed by the cabinet 26 and the back cover 27. In addition, the support 28 is connected to the lower end of the chassis (23). In addition, a plurality of cutouts 26 are formed on the circuit board 24.

3 and 4 illustrate only a circuit board of an embodiment according to the present invention.

As shown, the circuit boards 31 and 41 in which the driving circuits are installed are provided with holes 32 and 42 for the plurality of connection devices 25 for attaching the circuit boards 31 and 41 to the chassis 23. There is a fastening device is coupled to this hole. In FIG. 3, the circuit boards 31 and 41 are mounted on the chassis 23 by the boss 25a and the set screw 25b formed in the chassis 23. As shown, the circuit boards 31 and 41 are spaced apart from the chassis 23 by a predetermined height due to the height of the boss 25a. In addition, a plurality of circuit elements 33 and 43 serving as noise sources are provided on the circuit boards 31 and 41, and non-functional portions of the circuit boards 31 and 41 are cut out and formed on the circuit boards 31 and 41. Cutouts 34 and 44 are included. The direction, number, and shape of the cutouts 34 and 44 may vary depending on the size of the circuit boards 31 and 41 or the arrangement of the circuits. Reference numeral 34 in FIG. 3 denotes a cutout 34 formed in a straight line in a propagation path of noise and vibration on the circuit board 31, and reference numeral 44 in FIG. 4 is formed in a curved shape around the connection device 25 to form a circuit. It is a notch which divides the board | substrate 41 into the fixed area | region 44a which is a part adjacent to the hole 42 for a connection device, and the flexible area | region 44b which is an outer part. The curved cutout 44 may be made discontinuously at regular intervals.

The plasma display panel assembly 20 attaches the adhesive sheet 22 to the chassis 23 on which the circuit board 24 is mounted, and applies pressure with the plasma display panel 21 and the chassis 23 attached thereto. To form.

The operation of the plasma display panel assembly according to the present invention configured as described above will be described with reference to FIG.

The vibration generated by the circuit elements 33 and 43 constituting the driving circuit of the plasma display panel 21 or transmitted by external force is transmitted to the heat sink (not shown) and the circuit board 24. For example, a case may be considered in which vibration generated in a field effect transistor (FET) is transmitted to a heat sink and a circuit board 24 attached to the FET. The heat sink and the circuit board 24 are connected by a lug so that vibration of the heat sink is transmitted to the circuit board 24, and the vibration is connected to the chassis 23 and the circuit board 24. Is transmitted to the chassis 23. The chassis 23 acts as a noise source that emits noise to the outside and generates considerable noise. Therefore, it is necessary to block the vibration transmitted to the chassis 23, which forms the cutout 26 on the circuit board 24 so that the vibration transmitted from the circuit element and the heat sink is cut off by the cutout 26. At the same time, the noise caused by the vibration transmitted to the chassis 23 through the coupling device 25 is reduced due to the change in the mode shape and the natural frequency of the circuit board 24 itself.

Tables 1 to 3 show the results of experiments comparing the conventional circuit board with the circuit board according to the present invention.

Table 1 and Table 2 show the overall noise measurements tested by applying vibration to the circuit board without the circuit elements installed.

5 is a plan view of a circuit board used to obtain the experimental results of Table 1.

Referring to FIG. 5, a straight cut 54 is formed in the center of the circuit board 51, holes 52 for connecting devices are formed at the edge and the center of the circuit board 51. The position 53 on the 51 is indicated.

The measurement frequency band was 50 Hz to 8 kHz, measured using a microphone at a distance of 20 cm and 1 cm from the center of the circuit board, and the circuit board was excited with a 159.2 Hz sine wave.

Type of circuit board Conventional circuit boards Improved circuit boards Distance from position (cm) 20 One 20 One Noise measurement value (dBA) 40.1 45.2 37.3 38.4 37.3 45.2 34.3 35.0

Referring to Table 1, the noise of 2.8 to 3.0 dBA was reduced at a distance of 20 cm, it can be seen that the noise reduction effect of 6.8 to 10.2 dBA at a distance of 1 cm.

6 is a plan view of a circuit board used to obtain the experimental results of Table 2. FIG.

Referring to FIG. 6, a cutout 64 is formed around the connecting device of the circuit board 61, and there are holes 62 for the connecting device at the edge and the center of the circuit board 61, and the circuit board 61. The position 63 which has an excitation phase is shown. It is the same as the case of Table 1 of other experimental conditions.

Type of circuit board Conventional circuit boards Improved circuit boards Distance from position (cm) 20 One 20 One Noise measurement value (dBA) 38.2 42.8 36.1 41.9

Referring to Table 2, it can be seen that the noise of 2.1 dBA was reduced at a distance of 20 cm, and the noise reduction effect of 0.9 dBA at a distance of 1 cm.

Table 3 shows the experimental results using a circuit board provided with a circuit element.

7 is a plan view of a circuit board on which circuit elements used to obtain the experimental results of Table 1 are installed.

Referring to FIG. 7, a circuit element 72 is mounted on the circuit board 71, and holes 73 for connecting devices are formed at edges and centers of the circuit board 71, and around each hole. A plurality of cutouts 74 are formed. The experiment was conducted in full white with red (R), green (G), and B (blue), and noise was measured 50 cm from the center of the rear of the circuit. The measured values from the measuring frequency band 50 Hz to 8 kHz are shown in Table 3.

Type of circuit board Conventional circuit boards Improved circuit boards Experimental order Primary Secondary Primary Secondary Noise measurement value (dBA) 33.8 33.2 28.6 28.3

Referring to Table 3, when the improved circuit board is used, it can be seen that the noise is reduced from 4.6 to 5.5 dBA compared to the conventional.

As described above, the plasma display panel assembly of the present invention has noise blocking means for preventing the propagation of noise and vibration generated from the outside or the circuit itself on the circuit board as a component thereof, thereby reducing the noise generated by the vibration being transmitted to the chassis. You can.

Although the present invention has been described with reference to the embodiments shown in the drawings, it is merely exemplary, and it will be understood by those skilled in the art that various modifications and embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical details of the appended claims.

Claims (5)

A plasma display panel for forming an image by discharge, a chassis attached to a rear surface of the plasma display panel by an adhesive sheet to release heat generated from the plasma display panel, and a connection device spaced apart from the rear surface of the chassis by a predetermined interval. And at least one circuit board mounted through and having noise blocking means for blocking the propagation of vibration and noise generated from the elements of the driving circuit. The method of claim 1, And said noise blocking means comprises at least one cutout formed on a circuit board. The method of claim 2, And the cutout is formed in a straight line or a curved line on a propagation path of noise and vibration on a circuit board. The method of claim 2, And the cutout is curved or straight around the connection device to divide the circuit board into a fixed area and a flexible area. The method according to claim 3 or 4, And the cutout is discontinuously formed.