JP2010176078A - Led backlight structure of lcd module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LCD module having an inexpensive backlight structure. <P>SOLUTION: The LCD module includes: a printed board 2 specified to have an electrode on only one surface and to mount electronic components on only one surface; electronic components 3 mounted on the component mount surface of the printed board; a housing 1; and an LCD 4. The electronic components include at least one light-emitting element, and the optical axis of radiant light from the light-emitting element is in a perpendicular direction with respect to the printed board. The housing is in a box form having at least one opening, which is closed by the LCD. At least one reflection plane reflecting the radiant light of the light-emitting element toward the opening is disposed on the inner face of the housing. The printed board is placed to allow the radiant light of the light-emitting element mounted thereon to emit toward the reflection plane. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a structure of an LCD module having a backlight.

As a structure of an LCD module having a backlight, the structure of Patent Document 1 is proposed.

The backlight structure of Patent Document 1 is a surface that is electrically connected to a printed circuit board by reflow processing while fixing a bullet-type discrete component LED with a holder, and reflects light emitted from the LED to the printed circuit board. The housing is provided with an LCD, and an LCD is attached to the housing.

By the way, the discrete type LED element requires a separate holding part such as a holder as described above in order to maintain a precise position and direction because its lead frame is soft. The adoption of the separate holding component leads to an increase in component cost, an increase in the number of component mounting steps, and an increase in management cost.

On the other hand, since soldering of discrete type components must be performed in a separate process from soldering of surface mount components, the adoption of discrete components in the drive substrate of liquid crystal display devices that always include surface mount components such as LCD drivers The soldering process is required twice, which increases the number of man-hours and increases the unit price of the product, and should be avoided as much as possible.

Further, since it is necessary to make the soldering surface different between the surface mount component and the discrete component, it is necessary to employ a printed circuit board having at least two electrode layers, resulting in an increase in component cost.

As described above, the LCD module structure provided with the backlight having the conventional structure has a high cost.
JP 2007-155870 A

In order to solve the above problem, according to one aspect of the present invention, a printed circuit board having a specification that includes an electrode only on one side and mounts an electronic component only on one side;
Electronic components surface-mounted on the component mounting surface of the printed circuit board;
A housing and an LCD,
The electronic component includes at least one light emitting element,
The emitted light optical axis of the light emitting element is perpendicular to the printed circuit board;
The housing is box-shaped with at least one opening closed by the LCD;
The inner surface of the housing includes at least one reflection plane that reflects the emitted light of the light emitting element toward the opening,
The printed circuit board is arranged so that the emitted light of the mounted light emitting element is emitted toward the reflection plane,
An LCD module having a backlight structure characterized by the above.
Is provided.

According to another aspect of the present invention,
On the printed circuit board, a first region where a component having a mounting height equal to or lower than the light emitting portion of the light emitting element is mounted, and a component having a high mounting height relative to the light emitting portion of the light emitting element are mounted. The second region being
The first region is disposed on a side of the printed circuit board close to the LCD;
An LCD module having a backlight structure, wherein the second region is disposed on a side of the printed circuit board far from the LCD.
Is provided.

Furthermore, according to another aspect of the present invention,
The LCD module having a backlight structure, wherein the reflection plane is configured such that a normal line thereof has an intermediate inclination between a normal line of the printed circuit board and a normal line of the LCD.
Is provided.

By adopting the above configuration, it is possible to provide a low-cost LCD module that solves the problems of the conventional structure such as Patent Document 1.

The product of the present invention comprises the following components.

Single-sided printed circuit boards, surface-mount electronic components, housings, and liquid crystal panels.

Please refer to FIG.

A single-sided printed circuit board 2 is disposed on the inner surface of the housing 1. A surface mounting type electronic component 3 is mounted on the component mounting surface of the single-sided printed circuit board 2.

Here, at least one of the electronic components 3 is an electronic component 4 such as an LED or a small light bulb that emits light.

An inclined reflection plane 5 is formed at a position of the housing 1 facing the single-sided printed board 2.

A liquid crystal panel 7 is disposed in the opening 6 of the housing 1 so as to close the opening.

By adopting the above configuration, the emitted light from the electronic component 4 is reflected by the reflection plane 5 and illuminates the liquid crystal panel 7. In the configuration of the present application, since the optical path between the electronic component 4 and the liquid crystal panel is set to be sufficiently long, the liquid crystal panel 7 is uniformly illuminated when the emitted light intensity of the electronic component 4 has a predetermined dispersion. Will be.

In addition, in order to further improve the uniformity of illuminance, it is possible to arbitrarily select the diffusion plate 8.

On the single-sided substrate 2, an electronic component 9 that is taller than the electronic component 4 that emits light is mounted as a surface-mounted electronic component.

Examples of the electronic component 9 that is tall include a ROM connected through an aluminum electrolytic capacitor, a coil, and a socket.

The electronic component 9 is disposed on the non-liquid crystal panel side with respect to the electronic component 4 so as not to block the optical path of the electronic component 4 that emits light.

In the case of this embodiment, the mountable area of the tall electronic component 9 is limited to the area indicated by B.

By adopting such a configuration, it is possible to eliminate obstacles on the optical path, even though the surface-mounted electronic component 4 emits light at a position very close to the surface of the single-sided printed circuit board 2. It is possible to perform uniform illumination without obstruction such as unnecessary reflection and diffusion, and projection of shadows of electronic components on the LCD panel.

In addition, since all electronic components are surface-mounted, and only one mounting surface is required, the soldering process can be performed by a single reflow process, and man-hours can be reduced.

Reference is made to FIG. 2 as a second embodiment of the present invention.

The configuration of FIG. 2 is basically the same as that of FIG. 1 except that the reflective plane 5 does not exist at the position where the tall electronic component 9 is mounted.

Specifically, a space having a rectangular cross-sectional shape, for example, extends from a predetermined position of the reflection plane 5 to the back.

Since the reflection plane 5 reflects light emitted from the electronic component 4 that emits light, the reflection plane 5 is unnecessary in a region where light does not reach due to the radiated light intensity distribution of the electronic component 4.

For this reason, the reflection plane 5 does not exist above the mountable area of the tall electronic component 9.

In the case of this embodiment, since the back part 10 from the end part of the reflection plane 5 of the housing 1 can have any structure, there is virtually no restriction on the height of tall electronic components. .

FIG. 3 is referred to as a third embodiment of the present invention.

The configuration of FIG. 3 is characterized by a shape in which the area B is reduced.

In the case of this embodiment, the depth dimension of the housing 1 can be shortened, and space-saving mounting is possible.

FIG. 4 is referred to as a fourth embodiment of the present invention.

In the embodiment of FIG. 4, by providing an opening in the back portion 10, it can be used as an insertion port for the harness 11 that supplies power to the single-sided printed circuit board 2 and inputs signals.

Numerical limits such as dimensions of each part in each embodiment of the present application are as follows.

In the cross section including the normal line of the single-sided printed circuit board 2 and the liquid crystal panel 7, when the effective display area size of the liquid crystal panel 7 is a, the depth dimension of the reflection plane 5 is a, preferably 0.75a or more.

The inclination angle of the reflection plane 5 is an angle with the normal line of the single-sided printed circuit board and the normal line of the liquid crystal panel as the normal line, and the positional relationship in which the single-sided printed circuit board 2 and the liquid crystal panel 7 are orthogonal as shown in FIG. In this case, the angle is 45 degrees with respect to both the printed circuit board and the liquid crystal panel.

The arrangement of the electronic component 4 that emits light is preferably a position that is 0.5a to 0.75a behind the liquid crystal panel side 7 end of the reflection plane 5.

The electronic component 4 that emits light is assumed to be a surface-mounted LED, but any surface-mounting LED can be used regardless of the light-emitting principle.

For example, an EL element, a micro light bulb, a low pressure, a high pressure discharge lamp, etc. can be employed.

Especially for discharge lamps that require high voltage for light emission, it is necessary to construct a high-voltage circuit that includes coils, capacitors, etc. for boosting, but these components are generally much taller than other surface-mounted components. For this reason, it is difficult to arrange the LCD module. However, according to the configuration of the present invention, an LCD module can be formed without affecting the optical system by arranging the high voltage circuit in the region B.

In the present invention, the light emitting part is an LED package surface part filled with a PN junction surface or phosphor for an LED, a package surface part filled with a phosphor for an EL element, and a coil part for a light bulb. In the case of a discharge lamp, a part that actually emits light to the outside, such as an electric arc part or a phosphor part, is meant.

The present invention can be applied to an LCD module installed in a device that needs to display information.

It is a figure showing 1st Example of this invention. It is a figure showing the 2nd Example of this invention. It is a figure showing 3rd Example of this invention. It is a figure showing the 4th Example of this invention.

DESCRIPTION OF SYMBOLS 1 Housing 2 Single-sided printed circuit board 3 Electronic component 4 Light emitting electronic component 5 Reflection plane 6 Housing opening part 7 LCD panel 8 Diffusion plate 9 Tall electronic component 10 Back space 11 Harness

Claims (10)

A printed circuit board with specifications that have electrodes only on one side and electronic components only on one side,
Electronic components surface-mounted on the component mounting surface of the printed circuit board;
A housing and an LCD,
The electronic component includes at least one light emitting element,
The emitted light optical axis of the light emitting element is perpendicular to the printed circuit board;
The housing is box-shaped with at least one opening closed by the LCD;
The inner surface of the housing includes at least one reflection plane that reflects the emitted light of the light emitting element toward the opening,
The printed circuit board is arranged so that the emitted light of the mounted light emitting element is emitted toward the reflection plane,
An LCD module having a backlight structure characterized by the above. On the printed circuit board, a first region where a component having a mounting height equal to or lower than the light emitting portion of the light emitting element is mounted, and a component having a high mounting height relative to the light emitting portion of the light emitting element are mounted. The second region being
The first region is disposed on a side of the printed circuit board close to the LCD;
2. The LCD module having a backlight structure according to claim 1, wherein the second region is disposed on a side of the printed circuit board that is far from the LCD. 3. The backlight structure according to claim 1, wherein the reflection plane is configured such that a normal line thereof has an intermediate inclination between a normal line of the printed circuit board and a normal line of the LCD. 4. LCD module. In the cross section including the optical axis and the normal line of the LCD, when the effective display area size of the LCD is a,
The reflective plane has a depth dimension of a;
The light source is arranged at a position 0.5a from the LCD side end of the reflection plane,
The second region is arranged in a range of 0.75a or more from the LCD side end of the reflection plane, and the LCD side end of the box-shaped reflection plane has a size of 0 to 0.25a. The LCD module having a backlight structure according to claim 1, further comprising an opening edge portion extending in the opening direction. In the cross-sectional shape, the depth of the reflection plane is 0.75a or more,
5. The backlight according to claim 1, wherein the region of 0.75 a or more of the reflection plane has a rectangular shape connected to a non-LCD side end of the reflection plane. LCD module with structure. 6. The LCD module having a backlight structure according to claim 1, wherein the single-sided printed circuit board is provided inside the housing. 7. The LCD module having a backlight structure according to claim 1, wherein the single-sided printed board is provided outside the housing, and the housing has an opening on at least an optical path of the light emitting element. . The LCD module having a backlight structure according to claim 1, wherein the light emitting element is an LED. 9. The LCD module having a backlight structure according to claim 1, wherein the housing includes a surface on which the substrate can be mounted in parallel with an inner wall surface of the housing. 10. The LCD module having a backlight structure according to claim 1, wherein the opening is closed by the LCD.

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