KR20070018697A - Wire harness, lighting device, backlight device, and liquid crystal display device - Google Patents

Abstract

The present invention provides a wire harness suitable for supplying alternating current power, an illumination device using the same, a backlight device, and a liquid crystal display device. The solution means for achieving the above object includes a conductive member 1c and a conductive member ( A wire harness 1 having a covering member 1b made of a first insulating material covering and covering 1c and a supporting member 1a made of a second insulating material surrounding the covering member 1b with a space therebetween. By using this wire harness 1 for an illumination device, a backlight device, and a liquid crystal display device, the leakage current flowing through these devices was reduced.

Wire harness, lighting device, backlight device, liquid crystal display device

Description

Wire harness, lighting device, backlight device and liquid crystal display device {WIRE HARNESS, LIGHTING DEVICE, BACKLIGHT DEVICE, AND LIQUID CRYSTAL DISPLAY DEVICE}

1 is an external view of a liquid crystal display device of an embodiment.

2 is a block diagram of a liquid crystal display device of the embodiment.

3 is a view showing a drive controller of the liquid crystal display of the embodiment;

4 is a diagram showing a circuit example of the drive control circuit of the embodiment;

5 illustrates a wire harness of an embodiment.

Fig. 6 is a diagram showing a connection between a drive control unit and an illumination unit using the wire harness in the embodiment.

7 is a view showing a connection between a drive and a control unit and an illumination unit using wires in a comparative example.

8 shows a wire harness of an embodiment.

Fig. 9 is a view showing a drive controller and an illuminator using the wire harness of the embodiment.

10 is a view showing a drive controller and an illuminator using the wire harness of the embodiment;

Fig. 11 is a view showing a drive controller and an illuminator using the wire harness of the embodiment.

12 is a view showing a drive controller and an illuminator using the wire harness of the embodiment;

Fig. 13 is a view showing a drive controller and an illuminator using the wire harness of the embodiment.

Fig. 14 is a view showing a drive controller and an illuminator using the wire harness of the embodiment.

15 illustrates a backlight device using the wire harness of the embodiment.

Fig. 16 is a diagram showing an arrangement of respective components of the liquid crystal display device of the embodiment.

17 shows a lighting device of the embodiment.

Field of technology

BACKGROUND OF THE INVENTION Field of the Invention The present invention is suitable for supplying alternating current power by using a wire harness for interconnecting electrical members arranged separately in various devices such as electric devices and automobiles, and using the wire harnesses. It is about.

Prior art

Background Art Conventionally, wire harnesses have been widely used in various devices such as lighting devices, backlight devices, liquid crystal display devices, and even automobiles as electric devices. The wire harness interconnects electrical devices, electrical components, or electrical blocks (collectively referred to herein as electrical components), physically separated and disposed, and exchanges electrical signals or power between their electrical components. It is to. In other words, the wire harness is a predetermined one having a predetermined length, a bending shape, or the like of one or a plurality of sets of electric wires. The time for connecting the wires is shortened, miswiring is prevented, and the arrangement of the wires is uniformized to improve the product quality.

In particular, in the field of electric devices, recently, liquid crystal display devices are showing signs of rapidly spreading in general homes. In such a non-self-emitting display device, a backlight unit (lighting unit) using a cold cathode fluorescent tube is provided as a light source, and the drive and control unit for driving the lighting unit is mutually covered with a conductive wire (wire) of a conductive material. The backlight device connected and comprised is employ | adopted. In addition, the cold cathode fluorescent tube driven at a frequency higher than the commercial power source frequency has high light emission efficiency, and has been used as an illuminating device for light.

Therefore, in the backlight device which has such an illumination part, a drive control part, and the illumination device for light, what turns on a cold cathode fluorescent tube using AC power of several 10 kHz is used frequently. Then, for example, a plurality of cold cathode fluorescent tubes are provided, and a technique of supplying electric power from one cold cathode fluorescent tube driving device by a conductive material wire (see Patent Document 1), and covering the body using an insulating material Techniques for reducing leakage current from electric wires (see Patent Document 2) and the like have been actively studied.

Also, in the field of automobiles, electric vehicles using synchronous motors have attracted attention. Also in this field, a sheathed wire connecting the synchronous motor and the control unit is required, and the current flowing through the sheathed wire is an alternating current, so that a leak current is generated. Same as in the device.

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-303848

Patent Document 2: Japanese Patent Application Laid-Open No. 2001-255527

Also in the liquid crystal display device mentioned above, in order to improve mass productivity, it is preferable to employ | adopt a wire harness for a backlight device. On the other hand, in recent years, the big screen of a liquid crystal display device progresses gradually, the backlight device also enlarges with this, and the electric power for driving a cold cathode fluorescent tube is also increasing. Moreover, as shown in patent document 1, the aspect which drives several cold cathode fluorescent tubes sequentially by one inverter circuit (drive control circuit), or drives several cold cathode fluorescent tubes simultaneously is increasing. . As a result, the length of the wire harness becomes longer as compared with the case where one cold cathode fluorescent tube is driven by one inverter circuit. In addition, in the lighting device for the light, the distance between the cold cathode fluorescent tube and the driving power unit is separated in order to achieve the purpose of increasing the degree of freedom of design. In the field of automobiles, the synchronous operation of the driving power unit and the AC power is performed. The mutual distance between the motors is more separated by the so-called wheel-in-motor method, and any of them tends to increase the length of the wire harness connecting the driving power unit and the load circuit. have.

In such a case, as in the case of the conventionally used in electric equipment, automobiles, etc., as the wire harness which bundles the covered wires in stages and is molded in the shape along the wiring path, the conductive material body (for example, iron or aluminum chassis) The absolute amount of the leakage current flowing to the circuit increases, and the electric power from the drive / control unit does not effectively reach a load circuit such as a cold cathode fluorescent tube. For this reason, for example, in a backlight device, the fall of luminous efficiency or the enlargement of the drive control part, and also the increase of unnecessary device power consumption are brought about. On the other hand, as shown in Patent Literature 2, when an insulating material is used for the body, even if the leakage current can be reduced, the problem to be overcome also remains due to the strength of the body and the electronic unnecessary radiation countermeasure. In addition, in lighting devices for electric lighting and electric vehicles, the same problem to be solved has arisen with high power and high frequency of an AC power frequency.

SUMMARY OF THE INVENTION In view of the above-described problems, the present invention provides a lighting device, a backlight device, and a liquid crystal display device having a small leakage of AC power and suitable for supplying AC power, and supplying AC power using the wire harness. For the purpose.

The wire harness of the present invention includes a conductive member for interconnecting electrical members for electrical conduction, a covering member comprising a first insulating material surrounding and covering the conductive member, and surrounding the covering member with a space therebetween. A supporting member made of a second insulating material is provided.

In this wire harness, the conductive member interconnects the electrical members to achieve electrical conduction. The covering member made of the first insulating material surrounds and covers the conductive member. The support member surrounds the covering member with a space.

An illumination device of the present invention is a conductive member coated with an insulating material and a lighting unit having a drive power supply unit for supplying AC power, a cold cathode fluorescent tube to which the AC power is supplied, and a body for supporting the cold cathode fluorescent tube; The conductive power supply unit and the cold cathode fluorescent tube are connected to each other to achieve electrical conduction, and are surrounded by a support member made of an insulating material, and have a conductive member disposed along the body. This suppresses the leakage of the AC power.

This lighting apparatus connects a drive power supply part and an illumination part with a conductive member, and makes the cold cathode fluorescent tube of an illumination part light by AC power from a drive power supply part. The conductive member is surrounded by a supporting member made of an insulating material with a space, thereby suppressing leakage of AC power.

The backlight device of the present invention is a backlight device for irradiating light from the back of an image display surface, the backlight device comprising: a driving power supply unit for supplying AC power, a cold cathode fluorescent tube to which the AC power is supplied, and the cold cathode fluorescent tube; An illumination member having a body and a conductive member covered by an insulating material, wherein the drive power supply unit and the cold cathode fluorescent tube are interconnected to achieve electrical conduction, and are surrounded by a support member made of an insulating material, surrounded by a space. A conductive member disposed along the body is provided, and the support member suppresses the leakage of the AC power.

This backlight device functions as a backlight device by irradiating light from the back of the image display surface. The driving power supply unit and the lighting unit are connected to the conductive member, and the cold cathode fluorescent tube of the lighting unit is made to emit light by AC power from the driving power supply unit. The conductive member is surrounded by a supporting member made of an insulating material with a space, thereby suppressing leakage of AC power.

The liquid crystal display device of the present invention comprises a liquid crystal panel, a panel driver for driving a liquid crystal panel by generating a drive signal in response to a video signal, and a cold cathode fluorescent tube for irradiating light from the back of the image display surface of the liquid crystal panel. A liquid crystal display device comprising: an illumination unit having; and a driving power supply unit for supplying alternating current power to the illumination unit, the liquid crystal display device comprising: a conductive member, a covering member comprising a first insulating material surrounding and covering the conductive member; And a wire harness formed with a supporting member made of a second insulating material arranged so as to surround the gap, wherein the driving power supply unit and the lighting unit are interconnected by the conductive member forming the wire harness.

The liquid crystal display device includes a panel driver, an illumination unit, and a driving power supply unit, and includes a conductive member, a covering member made of a first insulating material surrounding the conductive member and covering the covering member with a space therebetween. By the wire harness formed with the support member which consists of the 2nd insulating material arrange | positioned, an illumination part and a drive power supply part are connected, and the leak of AC power is suppressed.

EMBODIMENT OF THE INVENTION Hereinafter, an Example is described according to drawing. First, a description will be given of a general liquid crystal display device according to Figs. 1 and 2, and according to Fig. 3, a drive / control part and a load circuit in the embodiment used for a liquid crystal display device and functioning as an example of a driving power supply part in the embodiment. An example of a backlight device formed mainly of a cold cathode fluorescent tube serving as an example will be described. The other form of the drive control circuit of the drive control part shown in FIG. 4 is shown, and this is demonstrated. The configuration and operation of the wire harness will be described according to FIG. 5. 6, the connection of the drive control part using a wire harness of an Example, and an illumination part is demonstrated, and the connection of the drive control part using a wire of a comparative example and an illumination part is demonstrated according to FIG. 8 shows a wire harness of another embodiment, and according to FIGS. 9 to 14, a mode of connection between a drive control unit and an illumination unit using wire harnesses of various embodiments will be described, and a backlight will also be described. Describe the device. 15 and 16, the aspect of the connection between the drive controller and the illumination unit using the wire harness of various embodiments will be described, and the backlight device and the liquid crystal display device will be described. In addition, the lighting apparatus for the purpose of light only using the wire harness according to FIG. 17 is demonstrated.

(Description of the liquid crystal display device)

First, the liquid crystal display device of an Example is demonstrated with reference to the external view shown in FIG. 1, and the block diagram shown in FIG. The perspective view shown in FIG. 1A shows the appearance of a liquid crystal display device in which the liquid crystal panel display surface 61 on the surface side (image viewing surface side) of the liquid crystal panel 22 (see FIG. 2) is viewed obliquely downward. FIG. 1: (B) is a perspective view of the liquid crystal display device which saw the back surface side (side other than the image viewing surface side) which is a surface on the opposite side to the liquid crystal panel display surface 61 in the inclined upper direction.

The liquid crystal panel display surface 61 and the chassis 63 are fixed to and supported by a body 62 arranged to surround four surfaces on the top, bottom, left and right sides. Here, in the chassis 63, a main electric circuit including a balance coil unit 64a and a balance coil unit 64b, which will be described later, at both ends of the liquid crystal display device, respectively, is shown in FIG. The screw members 65a to 65d shown in the figure are fixed and arranged. The chassis 63 is made of conductive iron or aluminum (aluminum).

For example, twenty-two cold cathode fluorescent tubes (not shown) are disposed between the rear surface side of the liquid crystal panel display surface 61 and the chassis 63. The cold cathode fluorescent tube has a thin and long columnar shape, and each cold cathode fluorescent tube is parallel to each other, and the body (in the longitudinal direction of the liquid crystal panel display surface 61 (the transverse direction of the surface of Fig. 1)). It is arranged parallel to the longitudinal direction of 62). In addition, each of the cold cathode fluorescent tubes has electrodes at both ends thereof, and each of the electrodes disposed at both ends of the plurality of cold cathode fluorescent tubes has a balance coil unit 64a and a balance coil unit 64b. Power is supplied from each. Thus, the balance coil unit 64a and the balance coil unit 64b are arrange | positioned in the vicinity of the electrode of each cold cathode fluorescent tube, and the electric current which flows through a cold cathode fluorescent tube is aimed at. The balance coil unit 64a and the balance coil unit 64b are supplied with electric power using a wire harness extending from the driving power supply unit over a long distance. In order to make the liquid crystal display device thin, the wire harness is And close to the chassis 63 formed of iron or aluminum. This will be described later in more detail with reference to FIGS. 15 and 16.

The liquid crystal display device 20 is shown as a block diagram in FIG. In the liquid crystal display device 20, a video signal is input from the video terminal tv. This video signal is supplied to the panel driver 21. The panel driver 21 performs necessary video signal processing on the input video signal, and generates a drive signal for driving the liquid crystal panel 22 so that image display based on the input video signal is performed. The liquid crystal panel 22 displays an image in response to the video signal by performing an operation in response to the drive signal generated by the panel driver 21 in this manner. However, the image is not visible.

The illumination part 23 is equipped with the cold cathode fluorescent tube as a light source, The illumination part 23 is driven by the drive control part 5, and functions as a light source. Then, light is transmitted from the rear surface of the liquid crystal panel 22 (the surface opposite to the image viewing surface) so that the image corresponding to the video signal can be visually seen on the image viewing surface of the liquid crystal panel 22. In addition, the drive control part 5 and the panel drive part 21 are comprehensively controlled by the control part 24 so that a cooperative operation may be performed.

3 is a principle diagram of the drive control unit 5 for driving a cold cathode fluorescent tube, and includes a drive control unit having a drive control circuit 15 for driving one cold cathode fluorescent tube 10 as a main component. (5) is shown. The drive control circuit 15 includes an oscillation drive circuit 6, a transistor Q1, and a transistor Q2. The oscillation and drive circuit 6 is a circuit for driving the bases of the transistors Q1 and Q2. The collector of the transistor Q1 is connected to the DC voltage positive electrode side Vin + supplied to the drive controller 5, the emitter of the transistor Q1 is connected to the collector of the transistor Q2, and the transistor ( The emitter of Q2) is connected to the DC voltage cathode side Vin-. Here, in order to reduce the losses in the transistors Q1 and Q2, the transistors Q1 and Q2 are controlled to alternately repeat two states of conduction and disconnection, and the transistor Q1 is controlled. Transistor Q2 is disconnected when conduction, transistor Q2 conducts when transistor Q1 is disconnected, and a square wave is formed at the connection point between the emitter of transistor Q1 and the collector of transistor Q2. ) Voltage is generated.

The voltage of this square wave is applied to the electrodes Dm1 and Dm2 of the cold cathode fluorescent tube 10 through the capacitor C1. The capacitor C1 supports a voltage corresponding to the midpoint potential on the capacitor C1 and adjusts the amplitudes of the potentials of the electrodes Dm1 and Dm2 at the same level as that of the positive electrode. It is to vibrate.

It is of course possible to drive the cold cathode fluorescent tube by the voltage of the square wave, but in this embodiment, the current flowing through the cold cathode fluorescent tube is a sine wave using a resonant circuit, so that unnecessary radiation is generated. The occurrence of is reduced. 4 is a drive control circuit 105 using a resonant circuit. As described later, a resonant circuit composed of the transformer TR and the capacitor C1 shown in FIG. 6 may be used.

The drive control circuit 105 using the resonance circuit shown in FIG. 4 will be described. The drive control circuit 105 connects a current resonant converter to the rear end of the active filter. This drive control circuit 105 corresponds to so-called wide range corresponding to AC input voltages of both an AC 100V system and an AC 200V system. Here, the active filter is added to improve the power factor. As the current resonant converter, a configuration based on a punching type half bridge coupling method is adopted.

In this drive control circuit 105, a common mode noise filter by two common mode choke coils CMC and three across capacitors CL is shown in accordance with the illustrated connection mode for the commercial AC power supply AC. Is connected, and the bridge rectifier circuit Di is connected to this rear end. Further, a normal mode noise filter 125 formed by connecting one choke coil LN and two filter capacitors CN as shown in the rectifier output line of the bridge rectifier circuit Di is connected. The positive output terminal of the normal mode noise filter 125 is connected to the positive terminal of the smoothing capacitor Ci through the series connection of the inductor LPC and the fast recovery type rectifier diode D20. In addition, an RC snubber circuit composed of a capacitor Csn and a resistor Rsn is connected in parallel to the rectifier diode D20.

As the switching element Q3, a MOS-FET having a body diode D103 is selected, and the step-up type switching is performed by the switching element Q3, the inductor LPC, the rectifying diode D20, and the smoothing capacitor Ci. The regulator is configured to form the main part of the active filter for improving the power factor. The power factor and output voltage control circuit 120 is an integrated circuit (IC) for controlling the operation of the active filter which improves the power factor so that the power factor approaches one. The power factor and output voltage control circuit 120 includes a multiplier, a divider, an error voltage amplifier, a PWM control circuit, a drive circuit for outputting a drive signal for switching driving the switching element, and the like.

The voltage value obtained by dividing the voltage (commutation smoothing voltage Ei) of both ends of the smoothing capacitor Ci by the voltage dividing resistors R5 and R6 is input to the terminal T1 of the power factor / output voltage control circuit 120 and switched. From the connection point of the resistor R3 inserted between the source of the element Q103 and the primary earth, a signal corresponding to the current flowing through the bridge rectifier circuit Di to the terminal T2 through the resistor R4 is inputted. have. Further, the full-wave rectified pulsating voltage obtained at the output of the bridge rectifier circuit Di is divided by the resistor R7 and the resistor R8 and input to the terminal T4. The power factor and output voltage control circuit 120 maintains the voltage value divided by the voltage divider resistors R5 and R6 at a predetermined value to make a constant voltage, and divides the voltage and resistance divided by the resistors R7 and R8. The power factor is brought close to 1 by controlling the voltage input to the terminal T2 to be equal through R4. In addition, in this drive control circuit 105, description of the power supply part which supplies electric power to the power factor and output voltage control circuit 120, and the power supply part which supplies electric power to the oscillation / drive circuit mentioned later is abbreviate | omitted.

As described above, the current resonant converter at the rear end of the active filter has a half bridge connection between the switching element Q101 and the switching element Q102 constituted by two MOS-FETs, and the rectified smoothing capacitor Ci. Are connected in parallel. That is, the current resonant converter by the half bridge coupling method is formed. Here, the current resonant converter is driven, and each of the body diode D101 and the body diode D102 flows a reverse current when the switching element Q101 and the switching element Q102 are turned off. Form a path. The switching element Q101 and the switching element Q102 are switched and driven by the oscillation / drive circuit 102 by the switching frequency required by the timing which turns on / off alternately.

The converter transformer PIT is provided for transferring the switching output obtained by the switching element Q101 and the switching element Q102 from the primary side to the secondary side. One end of the primary winding N1 of the converter transformer PIT is connected to the connection point of the switching element Q101 and the switching element Q102 via the series resonant capacitor C101, and the other end thereof is 1. It is connected to the vehicle side earth. Here, the series resonant circuit is formed by the capacitance of the series resonant capacitor C101 and the liquid crystal inductance generated at both ends of the primary winding N1. This series resonant circuit generates a resonance operation by supplying a switching output. The capacitor Cp1 forms a partial voltage resonant circuit to reduce the losses in the switching element Q101 and the switching element Q102.

A secondary winding (N2) is recommended on the secondary side of the converter transformer (PIT). From this secondary winding N2, a sinusoidal voltage in response to the resonance operation can be obtained. Here, by appropriately selecting the turns ratio of the primary winding N1 and the secondary winding N2, a desired voltage can be obtained between the electrode Dm1 and the electrode Dm2 of the cold cathode fluorescent tube 10. Here, the capacitor C1 is for cutting the DC component, but since the DC voltage is not transmitted to the secondary winding N2, the secondary winding N2 is directly connected to the electrode Dm1 without providing the capacitor C1. It may be connected directly to the electrode Dm2.

(Description of the wire harness)

5 shows the wire harness of this embodiment. 5 (A) to 5 (C) are views of the wire harness viewed from one end side. The wire harness 1 shown in FIG. 5A shows a case where the wire harness consists of one conductive member 1c. Such a wire harness 1 is electrically conductive with the conductive member 1c. The coating member 1b which consists of an insulating material which encloses and covers the member 1c, and the support member 1a which consists of an insulating material which surrounds the covering member 1b with a space are formed. Here, the outer diameter of the supporting member 1a is represented by the distance D1, the thickness of the insulating material of the supporting member 1a is represented by the distance D2, and the diameter of the covering member 1b is represented by the distance D3.

The wire harness 2 shown in FIG. 5B shows a case where the wire harness consists of two conductive members 2c and 3c, and such a wire harness 2 is a conductive member. (2c), a covering member 2b made of an insulating material surrounding and covering the conductive member 2c, a supporting member 2a made of an insulating material surrounding the covering member 2b with a space, and a conductive member ( 3c, a covering member 3b made of an insulating material surrounding and covering the conductive member 3c, and a supporting member 3a made of an insulating material surrounding the covering member 3b. The supporting member 2a and the supporting member 3a are almost in close contact with each other and are arranged almost in parallel. The support member 2a and the support member 3a may be adhered to each other by an adhesive or the like, or may be bonded to each other by a binding band, and the support member 2a and the support member 3a may be bonded together. May be integrally molded in advance. Here, the distance from the center of the conductive member 2c to the center of the conductive member 3c is represented by the distance D4.

The wire harness 3 shown in FIG. 5C adds a shield 3d to the wire harness 2 shown in FIG. 5B, and the shield 3d is mesh-shaped. Or a conductive material surrounding the plate-like support member 2a and the support member 3a. The shield 3d may be formed by winding a mesh or flat tape around the wire harness 2 and further, having a space in the shield 3d formed of a hollow tube formed beforehand. It may be formed by inserting (2). In this manner, the shielded wire harness 3 generates better characteristics against electronic unnecessary radiation.

In any of the wire harness 1, the wire harness 2, and the wire harness 3 described above, these wire harnesses have a predetermined predetermined length and have a predetermined shape as needed. Here, a predetermined shape does not necessarily need to be the same as the final shape which attached this wire harness to an apparatus, but also includes the shape which makes it easy to attach to an apparatus. In addition, a mounting member (connector) for simply mounting both ends of the wire harness to the electrical member may be previously connected to these wire harnesses.

Further, in any of the wire harness 1, the wire harness 2 and the wire harness 3 described above, a space exists between the covering member and the supporting member. This space not only has the effect of improving the characteristics described later, but also in the manufacture of the wire harness, the conductive member (coated wire) coated on the covering member passes through the hollow portion of the supporting member. This has the effect of easily forming a wire harness.

Although the wire harness shown to FIG. 5A-FIG. 5C shows one or two conductive members, the same structure can be employ | adopted also when it has three or more conductive members. have. The wire harness having the above-described configuration can prevent the coating from being damaged because the coated wire is supported in the support member.

Next, the electrical characteristics of the wire harness having such a configuration will be described. First, the characteristic common to all is demonstrated according to FIG. 5 (A). The support member 1a has a strength which does not receive a deformation | transformation very much even when it is attached to an apparatus. For this reason, the cross-sectional shape of the wire harness 1 hardly changes. Therefore, each of the distance D1 which is the outer diameter of the support member 1a, the distance D2 which is the thickness of the insulating material of the support member 1a, and the distance D3 which is the outer diameter of the covering member 1b have roughly constant values. Keeping up. Here, since the supporting member 1a is disposed in close proximity to the conductive body of the device, for example, the chassis 63 formed of iron or aluminum (see FIG. 11), the conductive member 1c and the conductive material body. Capacitance is generated between and.

The relationship between the distance D1, the distance D2 and the distance D3 and the magnitude of the capacitance will be described. The distance D3, which is the outer diameter of the covering member 1b, is determined by the magnitude of the current flowing through the conductive member 1c and the voltage applied to the conductive member 1c. Millimeters). The inventor of the present application, when the distance D3, which is the outer diameter of the covering member 1b, is fixed to a diameter of 2.7 mm, the thickness of the distance D1, which is the outer diameter of the supporting member 1a, and the insulating material of the supporting member 1a. By varying the phosphorus distance D2 in various ways and outputting a constant electric power from the drive controller according to the magnitude of both, it is noted that the magnitude of the current flowing through the fluorescent display tube changes, and by experiment, The relationship between the distance D1, the distance D2, and the distance D3 is preferably found.

(Example)

Hereinafter, an Example is described. 6 is an embodiment of a backlight device for irradiating light from the back of the image display surface. This backlight device includes a part of the lighting unit 23a which is an embodiment of the lighting unit 23 shown in FIG. 2, a drive control unit 5a which is an embodiment of the drive control unit 5 shown in FIG. 3, and FIG. 5. The wire harness 1A to the wire harness 1D having the same configuration as the illustrated wire harness 1 are shown. That is, this embodiment is an embodiment of a backlight device for irradiating light from the back of the image display surface, and includes a drive / control unit 5a functioning as a drive power supply unit for supplying AC power, and a cold cathode to which AC power is supplied. An electric conductive member coated with an insulator and a lighting unit 23a having a fluorescent tube and a body for supporting the cold cathode fluorescent tube, and electrically conductive by connecting the drive / control unit 5a and the cold cathode fluorescent tube to each other. Together with a wire harness comprising a wire harness 1A to a wire harness 1D, which is also surrounded by a support member made of an insulating material and functions as a conductive member disposed along the body, It is characterized by suppressing the leakage of AC power.

Here, in the embodiment, the illumination unit 23a is configured by arranging 22 cold cathode fluorescent tubes in parallel, but in FIG. 6, only two cold cathode fluorescent tubes 10 and cold cathode fluorescent tubes 11 are shown. The description of the other 20 cold cathode fluorescent tubes is omitted.

The drive control unit 5a includes a transformer TR in addition to the drive control unit 5 shown in FIG. 3. The transformer TR is provided with the primary winding N1 and the secondary winding N2. Since the leakage inductance is increased by decreasing the coupling degree between the primary winding N1 and the secondary winding N2, a resonance circuit is formed by the leakage inductance and the capacitance of the capacitor C1, and the transformer TR A substantially sinusoidal waveform is formed in the secondary winding N2. As described above, the sinusoidal current flows through the wire harness 1A to the wire harness 1D and, further, other 40 wire harnesses (not shown) to form the cold cathode fluorescent tube 10 and the cold cathode fluorescent tube 11, Since the other 20 cold-cathode fluorescent tubes which are not shown are turned on, the generation of an electronic unnecessary radiation can be made small compared with the case where it lights by a square wave. Here, the drive control circuit 15 is given, for example, 300 V (volts) as a DC voltage, and appropriately adjusts the turns ratio of the secondary winding N2 and the primary winding N1 of the transformer TR. By doing so, 700 V (RMS value) is obtained for the secondary winding N2.

Although the drive control circuit 15 shown in FIG. 3 is used as the drive control circuit of the drive control unit 5a, the drive control circuit 105 using the resonance circuit shown in FIG. 4 is used. It would be good. In this case, the converter transformer PIT disposed in the drive control circuit 105 can be used in place of the transformer TR. In FIG. 6, the converter transformer PIT is connected to the secondary winding N2 of the transformer TR. Each of 44 wire harnesses including the wire harnesses 1A to 1D which are present is connected to the secondary winding N102 of the converter transformer PIT. In this manner, 22 cold cathode fluorescent tubes including the cold cathode fluorescent tube 10 and the cold cathode fluorescent tube 11 can be driven. In addition, when using the drive control circuit 105, it is not necessary to necessarily provide the capacitor | condenser C1. In any of the following embodiments of FIGS. 7 and 9 to 15, the drive control circuit 105 may be used instead of the drive control circuit 15. In this case, since the direct current component is not transmitted to the secondary side by the converter transformer PIT as described above, it is not necessary to necessarily provide the capacitor C1.

Each of the wire harness 1A, the wire harness 1B, the wire harness 1C, and the wire harness 1D has the same configuration as the wire harness 1 shown in FIG. 5A. Although 44 wire harnesses having the same configuration are used, in FIG. 6, the description is omitted, only four are shown, and the description for the other 40 is omitted. In addition, the lengths of the wire harnesses 1A to 1D and the other 40 wire harnesses are not the same, and are cut in a predetermined length in advance. By using such a wire harness, manufacture of a liquid crystal display device can be performed in a short time, and the mass production effect can be improved.

In the present embodiment, the average value of the lengths of the 44 wire harnesses is 750 mm. In the case where a drive control circuit is provided for each cold cathode fluorescent tube and the cold cathode fluorescent tube is connected to the drive control circuit (not shown) It becomes longer compared with 100 mm of). In addition, the 44 wire harnesses include 22 wire harnesses on the right side (including wire harness 1A and wire harness 1B) and 22 wire harnesses on the left side (wire harness 1C and wire harness 1D). It is good to make it into a predetermined shape by tying each band together with a binding band, and to make it the wire harness of a larger division, but in this embodiment, it is set as 44 independent wire harnesses. In the present embodiment, the distance D3, which is the diameter of the conductive member 1c, is set to an outer diameter of 2.7 mm (millimeters) as described above, and the distance D1, which is the outer diameter of the supporting member 1a, is set to 4 mm. The distance D2, which is the thickness of the insulating material of the supporting member 1a, was 0.5 mm. In this case, the average value of the amount of current flowing through the 22 cold cathode fluorescent tubes is 5.859 mA (milliampere: RMS value). In addition, polyethylene was used for the insulating material of the support member.

(Comparative Example)

The comparative example compared with the Example is shown in FIG. In the comparative example, unlike the embodiment, the drive / control part 5a and the illumination part are formed by a wire harness having no support member 1a, that is, a covered wire in which the covering member 1b is disposed on the conductive member 1c. Wiring between cold cathode fluorescent tubes arranged at 23 is provided. In Fig. 6, 50A, 50B, 50C and 50D are attached to each of the coated wires on which the covering member 1b is disposed on the conductive member 1c. Here, the average value of the magnitude | size of the electric current which flows through 22 cold-cathode fluorescent tubes in the case of using the same length of covered wire and having the same length as the Example which has distance D3 of 2.7 mm (millimeter) in diameter is 5.446 ㎃ (milliampere: RMS value).

That is, since the brightness of the cold cathode fluorescent tube is proportional to the current flowing through the cold cathode fluorescent tube, it is necessary to supplement the leakage current in order to make the cold cathode fluorescent tube a predetermined brightness. In the above-mentioned example, in the wire harness which does not have the support member 1a, the increase of 7% of leakage current is recognized, and is equivalent to the fall of the 7% of power conversion efficiency in the above-mentioned power supply part. Therefore, to compensate for this, the wire harness should be supplied with an extra 7% as compared with the case of using the wire harness having the supporting member 1a. Conversely, when using a wire harness having the supporting member 1a, the power conversion efficiency is equivalent to 7% improvement.

In this manner, when the support member 1a is provided, even when the same power is supplied from the drive / control unit 5a, a larger current flows through the cold cathode fluorescent tube than in the case where the support member 1a is not provided. The electric power supplied from the drive control unit 5a can be used more effectively. As a result, the power efficiency of a liquid crystal display device improves and power saving can be aimed at.

(About difference in leakage current in an Example and a comparative example)

The inventor of the present application assumes that such a power-cutting effect occurs when the supporting member 1a is caused by a large factor of the leakage current from the wire harness. That is, not all of the electric power supplied from the drive controller 5a reaches the cold cathode fluorescent tube, but each of the wire harness 1A and the like shown in FIG. 6 or the wire harness 50A and the like shown in FIG. The drive / control unit may be formed by the capacitance between the chassis formed of iron or aluminum, and the mutual capacitance of the wire harnesses such as the wire harness 1A or the mutual capacitance of the wires such as the wire harness 50A. It is thought that the electric power supplied from 5a) leaks as a leak current, and the magnitude | size of the electric current which reaches a cold cathode fluorescent tube decreases.

That is, the leakage current from the wire harness 1A shown in FIG. 6 and the leakage current from the wire harness 50A shown in FIG. 7 are both increased as the voltage applied to the wire harness increases, and the length of the wire harness is increased. The longer it gets, the bigger it gets, the larger the wire harness approaches the metal chassis. For example, the voltage applied to the wire harness is about 700 V as a sine wave voltage, and the length of the wire harness is about 1 m from several tens of centimeters (cm / meter). Such a wire harness is closely adhered to the metal chassis with adhesive or adhesive tape. If there is, the difference between the magnitude of the leakage current from the wire harness 1A and the magnitude of the leakage current from the wire harness 50A cannot be ignored. The tendency of this leakage current to increase is gradually increasing with the increase of screen size and thickness.

First, the capacitance that causes the leakage current will be described. 6 and 7 schematically show some of these capacitances that actually exist. In Figure 6, the capacitance CAN is the capacitance between the wire harness 1A and the iron or aluminum chassis, and the capacitance CBN is the capacitance between the wire harness 1B and the chassis of iron or aluminum, the capacitance ( CCN) represents the capacitance between the wire harness 1C and the chassis of iron or aluminum, and capacitance (CDN) represents each of the capacitance between the wire harness 1D and the chassis of iron or aluminum, and the other 40 wires. For the harness, there is also a capacitance between each wire harness and the chassis of iron or aluminum. However, in FIG. 6, the description is omitted about the capacitance between the other 40 wire harnesses and the chassis of iron or aluminum.

In addition, the capacitance CABN is the capacitance existing between the wire harness 1A and the wire harness 1B, and the capacitance CCDN is the capacitance of the capacitance existing between the wire harness 1C and the wire harness 1D. Each one. In addition, although capacitance exists with each other 40 wire harness which runs in parallel, description is abbreviate | omitted in FIG. In addition, although a capacitance exists between the wire harness 1A and the wire harness 1C or the wire harness 1D and the wire harness 1B and the wire harness 1C or the wire harness 1D, the wire harness 1A And the wire harness 1B is arranged in the right direction, and the wire harness 1C and the wire harness 1D are arranged in the left direction, so that the capacitance between the wire harness in the right direction and the wire harness in the left direction is arranged. Is small enough not to be considered.

In FIG. 7, the capacitance CA is the capacitance between the wire 50A and the chassis of iron or aluminum, and the capacitance CB is the capacitance between the wire 50B and the chassis of iron or aluminum, and the capacitance. CC represents the capacitance between the wire 50C and the chassis of iron or aluminum, and capacitance CD represents each of the capacitance between the wire 50D and the chassis of iron or aluminum, and the other 40 Regarding the wire harness, there is an electrostatic capacitance between the wire harness and the chassis of iron or aluminum, respectively, but the description is omitted in FIG.

In addition, the capacitance CAB represents the capacitance existing between the wire 50A and the wire 50B, and the capacitance CCD represents each of the capacitances existing between the wire 50C and the wire 50D. To indicate. In addition, although capacitance exists with each other with 20 wire harnesses running in parallel, the description is omitted in FIG. In addition, although capacitance is also present between the wire 50A and the wire 50C or the wire 50D and the wire 50B and the wire 50C or the wire 50D, the wire 50A and the wire 50B are right. In the direction, since the wires 50A and 50B are arranged in the left direction, the capacitance between them is small enough not to be taken into consideration.

In addition, although the above-mentioned capacitance was shown equivalently by one capacitor | conductor in all cases in the case shown in FIG. 7, in the case where it shows in FIG. 6, in fact, an electrostatic capacitance is a distributed capacitance. Here, in the case where each of the distance D1, the distance D2, and the distance D3 is fixed, the largest capacitance between the conductive member 1c and the chassis of iron or aluminum is the largest. And the supporting member 1a are in contact with each other, and the supporting member 1a is sandwiched between the iron or aluminum chassis and the covering member 1b. On the other hand, the smallest capacitance between the conductive member 1c and the chassis of iron or aluminum is the case where the space between the conductive member 1c and the chassis of iron or aluminum is the largest.

Thus, the magnitude of the capacitance is not only the distance D1, the distance D2 and the distance D3, but also how the covering member 1b (ie, the conductive member 1c) is disposed among the supporting members 1a. Will depend on. In each wire harness, a preferred arrangement for the smallest capacitance between the conductive member 1c and the chassis of iron or aluminum is to attach the conductive member 1c to one wall surface of the supporting member 1a, and Although the surface to which the affixed was detached from the chassis of iron or aluminum as much as possible, when employ | adopting such a structure, adhesion | attachment and direction management are needed, and mass productivity will become inadequate. In another embodiment, in order to arrange the conductive member 1c on one side of the support member 1a, it is conceivable to fill the space with an insulator (dielectric material), but in this case, the action of the dielectric having a large dielectric constant is considered. As a result, the capacitance increases. On the other hand, the space filled with air formed on the inner surface of the supporting member 1a has the effect of preventing the increase in the electrostatic capacity because the relative dielectric constant of the air is about one.

The inventors found out from the above-mentioned welds that there are certain limitations in the ranges of the distance D1, the distance D2, and the distance D3 which exhibited a desirable effect of reducing the leakage current. That is, when the distance D1 is two large in the distance D3, the conductive member 1c comes into contact with the bottom surface (the surface having the lowest position in the direction of gravity) of the support member 1a, thereby reducing the leakage current. I can't show it. Further, when the distance D2 is two large in the distance D1, that is, when the thickness of the supporting member 1a indicated by the distance D2 is too thick, the capacitance increases due to the action of the dielectric, Rather, the value of the leakage current becomes large. For this reason, it is preferable that the material of the support member 1a is an insulating material of low dielectric constant, and while maintaining the rigidity as a support member, for example, the rigidity which does not crush in the case of being tied by the binding band, In addition, the flexibility of wiring the inside of the apparatus as a wire harness is also required. Thus, in the examples, polyethylene was used as the support member.

In addition, while the ratio between the outer circumferential inner surface area of the support member and the sectional area of the support member cross section of the support member formed of polyethylene is within a predetermined range (within the first predetermined range) while the outer circumferential surface of the support member 1a is surrounded , The ratio of the support member space area of the cross section surrounded by the inner circumferential surface of the support member 1a to the area of the cover member outer circumference of the cross section surrounded by the outer circumferential surface of the covering member 1b within a predetermined range (in the second predetermined range Need to be Here, in the embodiment, each of the support member outer circumferential area, the support member cross-sectional area, the support member space area, and the cover member outer circumferential inner area can be represented by the ratio of diameters because they are circular areas. That is, while the ratio of the distance D1 and the distance D2 is within a predetermined range (within the first predetermined range), the ratio between the distance between the distance D1 and the distance D2 and the distance D3 is predetermined. If it is in a range (in a 2nd predetermined range), the electrostatic capacity between a harness and the chassis of iron or aluminum can be made small, and the effect of reducing the leak current can be acquired.

These two predetermined ranges (first predetermined range and second predetermined range) are values that can be obtained from experimental values, for example, based on the amount of leakage current as an evaluation standard. In addition, the effect of the mutual capacitance (CABN) and the capacitance (CCDN) of the wire harnesses shown in FIG. 6 and the mutual capacitance (CAB) and the capacitance (CCD) of the wires shown in FIG. 7 will be described later. . The magnitude of the capacitance between the wire harnesses and the capacitance between the wires is, in the case of the wire harness 2 shown in Fig. 5, the distance D4 which is the distance between the conductive member 1c and the conductive member 2c. It depends on the size.

8A is a cross-sectional view in the longitudinal direction of the wire harness 31. In FIG. 8A, the conductive member 1c and the covering member 1b meander randomly in contact with the inner circumferential surface of the supporting member 1a. In such a case, the capacitance between the wire harness 31 and the chassis of iron or aluminum is, on average, arranged so that the conductive member 1c passes through the center of the supporting member 1a, and the conductive member (for the meandering portion) 1c) becomes long, and it can be considered that the capacitance increased by this amount. In other words, the wire harness 31 is considered to be able to realize an equivalent action to surrounding the wires by floating the space while maintaining a constant distance from the chassis of iron or aluminum by the action of the supporting member 1a. do.

In order to obtain such an effect, it is conceivable to make the length of the covering member 1b longer than the length of the supporting member 1a. Then, since the outer surface of the covering member 1b contacts the inner surface of the supporting member 1a while meandering, as a result, a wire harness having a small capacitance between the chassis of iron or aluminum can be realized. .

As another form of the wire harness formed on the basis of such a principle, there is a wire harness 32 shown in FIG. The wire harness 32 is a modification of the wire harness 2 shown in FIG. 5B, wherein each of the covering member 2b and the covering member 3b is a supporting member 2a and a supporting member 3a. I am meandering in). In addition, the same aspect as that of the wire harness 34 shown in FIG. 8C having four conductive members is possible. In the wire harness 34, each covering member meanders inside each supporting member. It is supposed to. Although an example of the wire harness 34 having four conductive members is shown in FIG. 8C, there is no technical limitation to the number of conductive members, and the wire harness having more than two conductive members is also shown. It is possible.

(Regarding another preferred embodiment of the liquid crystal display device using the wire harness)

9 to 16, another preferred embodiment of the backlight device using the above-described wire harness will be described. 9-16, the lighting part, the drive control part, and the wire harness which mutually connect are described, and since another part is the same as that of FIG. 2, the other part is not described.

FIG. 9 shows an illumination unit and a drive / control unit in which a large reduction effect of the leakage current occurs when the cold cathode fluorescent tube 10 disposed in the illumination unit 23B is long in the longitudinal direction. In FIG. 9, the code | symbol 1b, 1c is abbreviate | omitted and described the cover member 1b and the conductive member 1c of the wire harness 1 shown to FIG. 5 (A). In FIG. 9, one electrode end of the cold cathode fluorescent tube 10 is connected to one end of the secondary coil of the transformer TR by a relatively short connection line, and the other electrode end of the cold cathode fluorescent tube 10 is connected. Silver is connected to the other end of the secondary coil of the transformer TR with the wire harness 1. Since the capacitance between the conductive member 1c of the wire harness 1 and the chassis of iron or aluminum is small as described above, even if the length of the wire harness 1 is long, the amount of leakage current can be suppressed small. . In addition, the same effect can also be produced using the wire harness 31 shown in FIG. 8A instead of the wire harness 1.

FIG. 10 shows a lighting unit and a drive / control unit for reducing the electronic unnecessary radiation while reducing the leakage current when the cold cathode fluorescent tube 10 disposed in the lighting unit 23B is long in the longitudinal direction. 5a) is shown. In Fig. 10, reference numerals 2b and 2c and reference numerals 3b and 3c denote the cover member 2b, the cover member 3b and the conductive member 2c of the wire harness 2 shown in Fig. 5B. ), The conductive member 3c is omitted. Each of the electrode ends disposed at both ends in the longitudinal direction of the cold cathode fluorescent tube 10 is connected to one end of each of the secondary windings N2 of the transformer TRa and the transformer TRB having the same leakage inductance. It is connected by a relatively short connection line. In addition, each of the other ends of the transformer TRa and the transformer TRB is grounded. The transformer TRa and the transformer TRB act in the same manner as the transformer TR described above, and form a resonant circuit by the leakage inductance of the transformer TRa and the transformer TRB and the capacitor C1 to form cold cathode fluorescent light. A sinusoidal voltage is applied to each electrode of the tube 10, and the transformer TRa and the transformer TRB such that the polarity of the voltage V1 and the voltage V2 applied to each electrode are reverse polarity. ), The polarity of the coil is selected.

The transformer TRa and the drive control circuit 15 are arranged in close proximity, and the primary winding N1 of the transformer TRa is connected to the drive control circuit 15 by a short connection line. On the other hand, since the trance TRB is disposed near the electrode disposed in the cross section in the longitudinal direction of the cold cathode fluorescent tube, the distance from the drive control circuit 15 is far, and the primary of the trance TRB is large. The winding N1 is connected by the long wire harness 2. Even in such a long distance, the amount of leakage current flowing from the wire harness 2 to the chassis of iron or aluminum can be made small. In addition, by increasing the number of turns of the secondary winding N2 than the primary winding N1 of the transformer TRB, the voltage applied to the wire harness 2 can be lowered, thereby making the leakage current smaller. . In this embodiment, the transformer TRB forms a load circuit together with a cold cathode fluorescent tube.

On the other hand, in FIG. 6, since the capacitance as shown by the capacitance CABN exists between the conductive member 2c and the conductive member 3c of the wire harness 2 of FIG. Leak current flows. The leakage current generated by such capacitance between lines is different in magnitude from the leakage current in response to the voltage difference applied to each of the adjacent conductive member 2c and the conductive member 3c. The amount of electronic unnecessary radiation varies depending on the direction of the current flowing through each of the member 2c and the conductive member 3c.

Here, with respect to the voltage applied to each of the adjacent conductive member 2c and the conductive member 3c and the current flowing in both, the conductive member 1c and the conductive member (1c) are connected to the respective primary windings of the transformer TRB. Since one end of each of 2c is connected, as described above, a reverse polarity voltage is applied to the conductive member 2c and the conductive member 3c, and the reverse direction is applied to the conductive member 2c and the conductive member 3c. Current flows. On the other hand, regarding the capacitance, in the wire harness 2, the distance between the conductive member 2c and the conductive member 3c is approximately equally constant by the supporting member 2a and the supporting member 3a. As a result, the value of the capacitance becomes a value corresponding to the length of the wire harness 2. In addition, since the conductive member 2c and the conductive member 3c are separated from each other through the space formed by the supporting member 2a and the supporting member 3a, the covering member 2b and the covering member 3b come into close contact with each other. The magnitude of the capacitance is smaller than that in the case of the present invention.

Therefore, the value of the leakage current in response to the capacitance becomes smaller than the case where the covering member 2b and the covering member 3b are in close contact with each other, and flows to both the conductive member 2c and the conductive member 3c. Since the direction of the current is reverse, electromagnetically, it can be regarded as electromagnetic radiation from a short dipole, and the amount of electronic unnecessary radiation can be reduced. In addition, in the embodiment shown in FIG. 10, the wire harness 32 can also be used instead of the wire harness 2. In addition, when the number of cold cathode fluorescent tubes 10 arranged in the lighting unit 23B is not one, but plural, for example, 22, the electrodes of each cold cathode fluorescent tube are connected in parallel to connect the plurality of cold cathodes. Each of the fluorescent tubes can emit light at the same time.

FIG. 11 illustrates an illumination unit and a drive / control unit in which a large reduction effect of the leakage current is generated when there are a plurality of cold cathode fluorescent tubes arranged in the illumination unit 23B. In FIG. 11, although it is set as two of the cold cathode fluorescent tube 10 and the cold cathode fluorescent tube 11, even if it is three or more, the same structure can be employ | adopted and the same effect can be acquired. In this case, when the allowable current capacity per one of the conductive members constituting the wire harness is set as the current capacity per one of the cold cathode fluorescent tubes, a wire harness having the number of conductive members corresponding to the number of cold cathode fluorescent tubes is obtained. The formation can correspond to any number of cold cathode fluorescent tubes.

In FIG. 11, one end of the secondary coil of the transformer TR is connected to the conductive member 2c of the wire harness 2 on the right side and the conductive member 3c of the wire harness 2 on the right side. The other end of the secondary coil is connected to the conductive member 2c of the wire harness 2 on the left side and the conductive member 3c of the wire harness 2 on the left side. In this case, the direction of the current flowing through the conductive member 2c and the conductive member 3c of the wire harness 2 on the right side is the same direction, and the conductive member 2c and the conductive member 3c are coin-shaped. There is no voltage between them. For this reason, no leakage current flows through the electrostatic capacitance formed between the conductive member 2c and the conductive member 3c, and the leakage current is only a component flowing through the chassis of iron or aluminum. Similarly, the direction of the current flowing through the conductive member 2c and the conductive member 3c of the wire harness 2 on the left side is the same direction, and the conductive member 2c and the conductive member 3c are coin-shaped, and the left side The leak current does not flow in the electrostatic capacitance formed between the conductive member 2c and the conductive member 3c even with respect to the wire harness 2. In this way, the amount of leakage current can be made smaller.

In contrast to FIG. 11 in FIG. 12, the lighting unit 23a having the same configuration as that shown in FIG. 11, the drive / control unit 5a having the same configuration as that shown in FIG. 6, and that shown in FIG. 5 are shown. It is provided with the wire harness 2. In the case shown in FIG. 12, one end of the secondary coil of the transformer TR is connected to the conductive member 2c of the wire harness 2 on the right side and the conductive member 3c of the wire harness 2 on the left side. The other end of the secondary coil of the transformer TR is connected to the conductive member 3c of the wire harness 2 on the right side and the conductive member 2c of the wire harness 2 on the left side. In this manner, as in FIG. 10, currents flowing to adjacent conductive members can be reversed to each other. In this case, the amount of unnecessary radiation can be reduced as described above. 11 and 12, the wire harness 32 described above can be used in place of the wire harness 2.

6 and 9 to 12 described above, the drive and control unit which functions as a drive power supply unit for generating AC power by the wire harness having the conductive member and the supporting member shown in FIG. 5. And an illumination unit functioning as a load circuit supplied with AC power, and suppressing the leakage current from the conductive member by such a wire harness. On the other hand, when a large number of cold cathode fluorescent tubes are used in the lighting unit, as described above, the cold cathode fluorescent tubes are simply connected in parallel, and the magnitude of the current flowing through each cold cathode fluorescent tube is not uniform. have. The reason for this is that the lengths of the paths from the drive control unit to the respective cold cathode fluorescent tubes are different, and the magnitude of the leakage current from the conductive member connecting therebetween is different, and the characteristics of each cold cathode fluorescent tube are also different. This is because there is a deviation. 13 to 15 show a configuration of a drive / control unit which prevents a difference in the magnitude of the current flowing through each cold cathode fluorescent tube and allows a uniform current to flow through each cold cathode fluorescent tube. 16 shows a backlight device using such a drive and control unit.

The drive control unit 5b shown in FIG. 13 uniforms the current In1 flowing through the cold cathode fluorescent tube 10 and the current In2 flowing through the cold cathode fluorescent tube 11 using the balance coil Lb. It is to make it. Here, the balance coil Lb is also called a common mode choke coil. When the winding NLb1 and the winding Nlb2 have the same number of turns, the current flowing from the terminal Lbi is the current flowing from the terminal Lbo1. Classified into In1 and the current In2 flowing from the terminal Lbo2. The size of the current In1 is equal to the size of the current In2. That is, the current In1 is taken out from the terminal at the winding end of the winding NLb1, and the current In2 is taken out from the terminal at which the winding Nlb2 starts winding, but the winding NLb1 and the winding Nlb2 are taken out. ) Is magnetically tightly coupled to each other, the electromotive voltage is generated in each coil in response to the difference between the current In1 and the current In2, and the current (In1) is caused by the feedback effect. ) And current In2 are equivalent. In addition, each of the contact C1b1, the contact C1a1, the contact C1b2, the contact C1a2, the contact C2b, and the contact C2a are the contacts of the connector, and the drive control part 5b and the illumination part 23a are each. It is adopted to enable the putting on and taking off.

The drive control unit 5c shown in FIG. 14 uses the set of a plurality of balance coils as the balance coils Lb, so that the current flowing from the terminal Lbi is supplied to the current In1 from the terminal Lb01 and the terminal. It is classified into the current In2 from Lb02, the current In3 from the terminal Lb03, and the current In4 from the terminal Lb04. When the turns of the winding NLb1 and the winding Nlb2 are equal, and the turns of the winding NLb3 and the winding Nlb4 are equal, and the turns of the winding NLb5 and the winding Nlb6 are equal, Current In1 of the cold cathode fluorescent tube 10, Current In2 of the cold cathode fluorescent tube 11, Current In3 of the cold cathode fluorescent tube 12, In4 of the cold cathode fluorescent tube 13 The magnitudes of the currents flowing through each of?) Are all equal. Also, contact C1b1 and contact C1a1, contact C1b2 and contact C1a2, contact C1b3, contact C1a3, contact C1b4 and contact C1a4, contact C2b and contact Each of C2a) is a contact point of a connector, and is employed to enable attachment and detachment of the drive control unit 5c and the illumination unit 23a.

FIG. 15 illustrates a backlight device of the liquid crystal display device shown in FIGS. 1 and 2. One terminal of the secondary winding N2 of the transformer TR of the drive control unit 5a is connected to the conductive member of the wire harness 1f via the connector CNA, and is connected to the wire harness via the connector CNC. The conductive member of 1f is connected to the balance coil unit 64a. In addition, the other terminal of the secondary winding N2 of the transformer TR is connected to the conductive member of the wire harness 1g via the connector CNB, and is connected to the conductive member of the wire harness 1g via the connector CND. The conductive member is connected to the balance coil unit 64b. In addition, the balance coil unit 64a and the lighting unit 23a are connected via the connectors CN1a to Connector CN22a, and the balance coil unit 64b and the lighting unit 23a are the connectors CN1b to Connector CN22b. It is connected through. Here, the voltage generated at both ends of the secondary winding N2 of the transformer TR is 700V (volts), and the length of the wire harness 1g, the long wire harness, is 750 mm (millimeters). have. Since such a high voltage is applied to a long wire harness, when the conventional wire harness is used instead of the wire harness 1g, the magnitude of the leakage current becomes larger.

In the backlight device shown in FIG. 15, two balance coil units, a balance coil unit 64a and a balance coil unit 64b, are used. However, as shown in FIG. 14, only one electrode side is balanced. The unit may be used, and the other electrode side may directly connect electrodes with each other without using a balance unit. However, as shown in Fig. 15, by providing the balance coils on both sides of the electrodes, the uniformity of the current flowing through each cold cathode fluorescent tube can be further improved.

As shown in FIG. 10, two transformers of the transformer TRa and the transformer TRB are provided in place of the transformer TR, and the balance coil unit (2) is provided in the secondary winding N2 of the transformer TRa. 64a may be connected and the balance coil unit 64b may be connected to the secondary winding N2 of the transformer TRB. In this case, the transformer TRB has the same structure as the transformer TRa, and the number of turns of each of the secondary windings N2 disposed in the transformer TRa and the transformer TRB is used for the transformer TRa and the transformer. The leakage current is larger than the number of turns of each primary winding N1 disposed in the TRB, and the value of the voltage applied to the wire harness 1g, which is the longer wire harness, is made lower, and the leakage current is further reduced. Can be suppressed. For example, when the number of turns of the primary winding N1 is 1 and the number of turns of the secondary winding N2 is 4, the voltage applied to the wire harness 1g does not have the transformer TRB. It can reduce to 1/4 of a case and can suppress a leakage current. However, since two transformers are required, it is advantageous from the viewpoint of downsizing of the device to use the wire harness 1g of the present embodiment to suppress the leakage current.

Here, the balance coils Lb1a to the balance coils Lb21a are disposed in the balance coil unit 64a, and the balance coils Lb1b to the balance coils Lb21b are disposed in the balance coil unit 64b and the lighting unit ( The currents flowing through the cold cathode fluorescent tubes arranged in 23a) are assumed to be equivalent. In each balance coil other than the balance coil Lb20a and the balance coil Lb20b, the number of turns of the two coils which comprise a balance coil is equal. In the balance coil Lb20a and the balance coil Lb20b, since two cold cathode fluorescent tubes are connected to one winding and eight cold cathode fluorescent tubes are connected to the other winding, eight cold cathode fluorescent lamps are connected. If the number of turns of the winding on the side to which the tube is connected is 1, the number of turns of the winding on the side to which the two cold cathode fluorescent tubes are connected is four.

FIG. 16 shows the drive control unit 5a, the balance coil unit 64a, the balance coil unit 64b, the wire harness 1f, the wire harness 1g, and the cold cathode fluorescent tube (in the chassis 63). 16 shows only the cold cathode fluorescent tube 10 and the cold cathode fluorescent tube 11. Of the 22 cold cathode fluorescent tubes, the other 20 cold cathode fluorescent tubes are also arranged to be parallel to each other, but the description is omitted. Shows the arrangement of each. Here, the wire harness 1f and the wire harness 1g have the same structure as the wire harness 1 shown in Fig. 5A. In the arrangement shown in Fig. 16, by using the wire harness 1f and the wire harness 1g, the leakage current to the chassis 63 formed of conductive iron or aluminum can be reduced, and the balance is reduced. By using the coil unit 64a and the balance coil unit 64b, the electric current which flows in each cold cathode fluorescent tube can be made uniform, and the luminance of light emission of each cold cathode fluorescent tube can be made uniform.

Although not shown in the layout of each component part of the liquid crystal display device shown in FIG. 16, the signal processing board | substrate and panel drive circuit board contained in the panel drive part 21 (refer FIG. 2) are arrange | positioned. Since the panel drive part 21 is a part which has a large board | substrate area in the whole, and the frequency to handle is higher than the drive control part 5a, the arrangement position of the panel drive part 21 takes priority, It becomes difficult to arrange | position the drive control part 5a near the electrode of a cold cathode fluorescent tube, and the length of the wire harness 1f and the wire harness 1g becomes nonuniform, and both, or, The tendency of the length of one wire harness to become long is unavoidable. In the case where such circumstances of the liquid crystal display device are considered, the effect of reducing the leakage current by using the wire harness 1f and the wire harness 1g having the same structure as the wire harness 1 shown in FIG. 5 is shown. Is a big one.

FIG. 17 is an example of the case where the wire harness 1 and the wire harness 2 shown in FIG. 5B are used for the lighting device. All the embodiments related to the above-described backlight device can be applied to such a lighting device. Here, the circuit part of this lighting device is as shown in FIG. In the lighting apparatus shown in FIG. 17, in the lighting unit 23a of FIG. 13, only two cold cathode fluorescent tubes are replaced by the cold cathode fluorescent tubes 10 and the cold cathode fluorescent tubes 11. It is provided as 81a and cold cathode fluorescent tube 81b. The wire harness 2 (not shown in FIG. 17) has a terminal Lbo1 of the drive control unit 5b and one electrode (not shown in FIG. 17) of the cold cathode fluorescent tube 81a. It connects via the contact C1a1, and also connects the terminal Lbo2 of the drive control part 5b and one electrode (not shown in FIG. 17) of the cold cathode fluorescent tube 81b to the contact C1b2 and the contact C1a2. Connect via). In addition, the wire harness 1 (not shown in FIG. 17) is the secondary electrode N2 of the transformer TR of the drive control unit 5b and the other electrode of the cold cathode fluorescent tube 81a (FIG. 17). 17 and the other electrode of the cold cathode fluorescent tube 81b (not shown in FIG. 17) are connected via the contact C2b and the contact C2a. The support member 83 and the canopy 82 are formed of a conductive metal material having a hollow portion, and the wire harness 1 and the inside of the hollow portion of the support member 83 and canopy 82 are formed. The wire harness 2 passes through and is wired.

In the case of adopting such a structure, the drive / control unit 5b serving as a drive power supply unit for supplying AC power, which is a large structural unit attached to the bottom of the lighting device, and the AC power attached to the upper portion of the lighting device are supplied. The distance between the cold cathode fluorescent tube and the support member 83 for supporting the canopy 82 and the wire harness 1 and the wire harness 2 as a body for supporting the cold cathode fluorescent tube is long. Or a metal material, the capacitance between the wire harness 1 and the wire harness 2 and these metal materials is large, but is provided with a conductive member surrounded by space by a supporting member made of an insulating material. The leakage current from the wire harness 1 and the wire harness 2 can be made small. Moreover, the balance coil Lb arrange | positioned at the drive control part 5b can flow uniform current to the cold cathode fluorescent tube 81a and the cold cathode fluorescent tube 81b.

According to the present invention, it is possible to provide a wire harness having less leakage of AC power, an illumination device, a backlight device and a liquid crystal display device which supply AC power using the wire harness.

Claims (13)

A conductive member for interconnecting the electrical members to achieve electrical conduction; A covering member comprising a first insulating material surrounding and covering the conductive member; And a supporting member made of a second insulating material surrounding the covering member with a space therebetween. The method of claim 1, The area of the cross section surrounded by the inner circumferential surface of the support member, while the ratio between the outer circumferential inner surface of the support member and the cross sectional area of the cross section of the support member of the second insulating material is within the first predetermined range, and the inner circumferential surface of the support member is within the first predetermined range. A ratio of the ratio between the inner space of the covering member and the inner circumference of the covering member of the cross section surrounded by the phosphor supporting member space area and the outer circumferential surface of the covering member is within the second predetermined range. The method of claim 1, The support member has a first support member and a second support member, which are in close contact with each other and are arranged substantially parallel to each other. The method of claim 1, The covering member meanders, and a part of the covering member comes into contact with an inner surface of the support member. The method of claim 1, One of the electrical members interconnected by the conductive member is connected to a drive power supply unit for supplying AC power, The other side is connected to the load circuit to which the said AC power was supplied, A wire harness, wherein the support member suppresses leakage of the AC power. A driving power supply unit supplying AC power; An illumination unit having a cold cathode fluorescent tube to which the AC power is supplied and a body supporting the cold cathode fluorescent tube; A conductive member coated with an insulating material, wherein the drive power supply unit and the cold cathode fluorescent tube are interconnected to achieve electrical conduction, and are also spaced by a supporting member made of an insulating material, and are disposed along the body. With a conductive member, The support device suppresses the leakage of the AC power by the support member. The method of claim 6, And said illuminating section has a plurality of cold cathode fluorescent tubes, and AC power is supplied from said driving power supply section through a balance coil for equalizing the current flowing in these cold cathode fluorescent tubes. A backlight device for irradiating light from the back of an image display surface, A driving power supply unit supplying AC power; An illumination unit having a cold cathode fluorescent tube to which the AC power is supplied and a body supporting the cold cathode fluorescent tube; A conductive member coated with an insulating material, wherein the drive power supply unit and the cold cathode fluorescent tube are interconnected to achieve electrical conduction, and are also spaced by a supporting member made of an insulating material, and are disposed along the body. And a conductive member to suppress the leakage of the AC power by the support member. The method of claim 8, A plurality of cold cathode fluorescent tubes are provided, and AC power is supplied from the driving power supply unit through a balance coil for equalizing the current flowing through these cold cathode fluorescent tubes. A lighting unit having a liquid crystal panel, a panel driving unit for driving a liquid crystal panel by generating a driving signal in response to a video signal, and a cold cathode fluorescent tube for irradiating light from the rear surface of the image display surface of the liquid crystal panel; A liquid crystal display device comprising a driving power supply unit for supplying AC power, A wire harness formed with a conductive member, a covering member made of a first insulating material surrounding and covering the conductive member, and a supporting member made of a second insulating material arranged to surround the covering member with a space; And the drive power supply unit and the illumination unit are interconnected by the conductive member forming the wire harness. The method of claim 10, The support member of the wire harness has a first support member and a second support member disposed in close contact with each other and in parallel with each other, and the first conductive member and the second support member included in the first support member have the first support member. 2. A liquid crystal display device characterized in that the direction of voltage polarity applied to each of the conductive members is different. The method of claim 10, The support member of the wire harness has a first support member and a second support member disposed in close contact with each other and in parallel with each other, and the first conductive member and the second support member included in the first support member have the first support member. 2 The liquid crystal display device characterized in that the direction of the voltage polarity applied to the conductive member is in the same direction. The method of claim 10, A plurality of cold cathode fluorescent tubes are provided, and the AC power is supplied from the driving power supply unit through a balance coil for equalizing the current flowing through these cold cathode fluorescent tubes.

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