JP2008292849A - Illumination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination device capable of illuminating an LCD cell and a prescribed area in the vicinity thereof with colors different from each other, using a common light guide plate, and capable of restraining an undesired illumination caused by light leakage. <P>SOLUTION: This illumination device includes the light guide plate 6 formed integrally with: the first illumination part 6a for introducing a light (for example, green color light) from a light emitting element 4 to serve as a backlight of the LCD cell 7; the second illumination part 6b for introducing a light (for example, red color light) from a light emitting element 5 to illuminate the prescribed area 8b in a case 8; and a connection part 6c for connecting the both illumination parts 6a and 6b. The connection part 6c is provided with: a slit 61c cut in from a width-directional one-end side toward the other end side; and a recessed cut-out 62c cut in from the width-directional other end side toward the one end side, contrarily thereto, and the sum (d1+d2) of cut-in depths in the both 61c and 62c is made not to get less than a width dimension w of the connection part 6c. A shielding plate 9 is preferably arranged inside the slit 61c. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an illuminating device in which an LCD cell and a predetermined region in the vicinity thereof can be illuminated with different colors using a common light guide plate.

  In electronic devices that use LCD cells to display character information, etc., light from the light-emitting elements is introduced into the light guide plate that is placed on the back of the LCD cells (the surface opposite to the display surface) and supplies the backlight. The light emission color of the light emitting element becomes the illumination color of the backlight. In addition, in this type of electronic device, there is a case where a second illumination area having a small area capable of function display such as error display is provided in the vicinity of the LCD cell. Generally, the illumination color of the second illumination area is It is set to a color different from the illumination color of the backlight of the LCD cell.

  When the LCD cell and the second illumination area in the vicinity thereof are illuminated with different colors in this way, the light guide plate and the light emitting element for the LCD cell, and the light guide plate and the light emitting element for the second illumination area are provided. If the provided illumination device is used, each can be illuminated with a desired color, but the number of parts is large, the assemblability is poor, and the illumination device is expensive. Therefore, it is conceivable to integrally mold the light guide plate for the LCD cell and the light guide plate for the second illumination region. However, if the light guide plate is simply made common, the light emitting element for the LCD cell, for example, green Light leaks to the second illumination region side, or conversely, for example, red light of the light emitting element for the second illumination region leaks to the LCD cell side, so that the illumination quality is significantly deteriorated. That is, when the LCD cell and the second illumination area in the vicinity thereof are to be illuminated with different colors using a common light guide plate, the light of the light emitting element introduced into the light guide plate is directed in an undesired direction. It is necessary to take some measures for the light guide plate so that there is no such problem.

Conventionally, as a countermeasure for making it possible to illuminate different areas with a predetermined color using a common light guide plate, a technique of providing a light-shielding slit on the light guide plate has been proposed (see, for example, Patent Document 1). . In such prior art, a portion of the light guide plate where light from one light emitting element is introduced is surrounded by a U-shape with a slit except for a direction in which a specific region to be illuminated exists, thereby moving in an undesired direction. Most of the light from the light emitting element can be blocked by the slit. Since the specific area cannot be completely surrounded by the slit, the light of the other light emitting element also reaches the specific area. However, as described in Patent Document 1, If the light-emitting color of the light-emitting element is red and the light-emitting color of the other light-emitting element is orange, even if orange light is mixed into the specific area illuminated in red, it is hardly noticeable.
Japanese Patent Laid-Open No. 2001-183182 (page 3-4, FIG. 1)

  The above conventional proposal is to illuminate different areas with different colors by providing a U-shaped slit on a common light guide plate, but only one of these areas is illuminated and the other is not illuminated. When the use state is assumed, even if such a slit is provided, good illumination quality cannot be expected. That is, as described above, since the slit of the light guide plate cannot be formed in a closed shape, it is inevitable that the light from the light emitting element leaks to some extent in the undesired direction through the portion where the slit is interrupted. When only one of the regions is illuminated (only one of the light emitting elements is turned on), there is a high possibility that the other region that should be in a non-illuminated state is lightly illuminated by the light of the light emitting element.

  The present invention has been made in view of the situation of the prior art as described above, and an object of the present invention is to illuminate the LCD cell and a predetermined area in the vicinity thereof with different colors using a common light guide plate, and An object of the present invention is to provide an illumination device that can easily suppress undesired illumination caused by light leakage.

  In order to achieve the above object, in the present invention, a first light emitting element and a second light emitting element which are mounted on a circuit board and have different emission colors, and light from the first light emitting element is introduced. A light guide plate formed by integrally forming one illumination portion and a second illumination portion into which light from the second light emitting element is introduced, and a backlight of an LCD cell mounted on the circuit board includes the first illumination portion. And an illumination device capable of illuminating a predetermined region near the LCD cell by the second illumination unit, wherein the first illumination unit and the second illumination unit of the light guide plate A first notch portion cut from one end side in the width direction of the connecting portion toward the other end side, and a cut from the other end side of the connecting portion toward the one end side. A second notch, and the first and second notches The sum of which narrowing depth was set to a value not less than the width of the connecting portion.

  In this way, a pair of notches cut in opposite directions is provided in the connecting portion connecting the first illumination portion and the second illumination portion of the light guide plate, and the depth of the notches of these notches is determined. If the sum is set to be equal to or larger than the width dimension of the connecting portion, most of the light passing from the one illuminating portion to the other illuminating portion through the connecting portion is directed to the first notch portion or the second notching portion. It will be blocked by the notch. Therefore, when the predetermined area in the vicinity of the LCD cell is not illuminated by the second illumination section, there is almost no risk that the predetermined area is illuminated by the light for the first illumination section (for example, green light). Further, there is almost no possibility that the light for the second illuminating part (for example, red light) is mixed into the backlight of the LCD cell, and light leakage that causes undesired name illumination can be effectively suppressed.

  In the above configuration, when one of the first and second cutouts is a slit that locally narrows the connecting part, it is easy to increase the light shielding effect by arranging a light shielding plate in the slit. It becomes. In this case, if the light shielding plate is extended at a position facing the back surface of the second illumination unit, there is no possibility that undesired light enters the second illumination unit via the back surface. The illumination quality is further enhanced. In addition, in the configuration in which the light shielding plate is disposed in the slit of the connecting portion, if the light shielding plate is sandwiched between the narrow portion of the connecting portion and the circuit board, the light shielding plate is bonded and fixed or held by a dedicated member. This is preferable because there is no need to do this.

  According to the illumination device of the present invention, the light guide plate is formed by integrally forming the first illumination unit serving as the backlight of the LCD cell and the second illumination unit capable of illuminating a predetermined area near the LCD cell. A first notch and a second notch that are cut in opposite directions to each other so that the sum of the depths of cut is not less than the width of the connecting portion. Since the portion is provided, most of the light traveling from the one illumination portion to the other illumination portion through the connecting portion is blocked by the first notch portion or the second notch portion. Therefore, when the predetermined area in the vicinity of the LCD cell is not illuminated by the second illuminating unit, there is almost no possibility that the predetermined area is illuminated by the light leakage from the first illuminating unit, and similarly to the backlight of the LCD cell. There is almost no risk of leakage of light from the second illumination unit, and light leakage that causes undesired illumination can be effectively suppressed. In addition, since the light guide plate for illuminating different regions with different colors is an integrally molded product, the number of parts can be reduced, the assemblability can be improved, and a low-cost illumination device can be obtained.

  1 is a front view of an electronic device with an LCD according to an embodiment of the present invention, FIG. 2 is a schematic perspective view showing an internal structure of the electronic device, and FIG. Fig. 4 is a cross-sectional view of the main part showing the LCD mounting structure of the electronic device, Fig. 4 is a perspective view of the main part of the light guide plate provided in the electronic device as viewed from the back side, and Fig. 5 is a part of the light guide plate. FIG. 6 is a perspective view of a light shielding plate provided in the electronic device, and FIG. 7 is a diagram for attaching an LCD cell and a light guide plate to a circuit board in the assembly process of the electronic device. It is explanatory drawing of.

  The electronic apparatus shown in these drawings includes a circuit board 1 in which various electronic components 2, 3 and light emitting elements (LEDs) 4, 5 are disposed on one main surface 1a serving as a component mounting surface, and a first illumination unit. The LCD cell 7 which is held by the light guide plate 6 having 6a and the second illumination part 6b and attached to one side of the circuit board 1 and the case 8 which is an outer shell member are mainly configured. In this electronic device, the first illumination part 6a of the light guide plate 6 into which the light of the light emitting element 4 (emission color is green) is introduced as a backlight on the back side of the LCD cell 7, and is illuminated with green light. Thus, the illumination area of the LCD cell 7 capable of displaying character information and the like can be viewed from the display surface 7a side. A display window 8 a for exposing the display surface 7 a of the LCD cell 7 is provided in the case 8. In addition, the second illumination part 6b of the light guide plate 6 into which the light of the light emitting element 5 (the emission color is red) is disposed is opposed to the illumination area 8b of the case 8 adjacent to the display window 8a. The second illumination unit 6b illuminates the illumination region 8b with red light so that function display such as error display can be performed. That is, the electronic device includes an illumination device including the light emitting elements 4 and 5 and the light guide plate 6.

  The LCD cell 7 has a rectangular outer shape, and has a group of terminals 7c at one side end portion 7b along the longitudinal direction thereof. The LCD cell 7 is mounted on one side of the circuit board 1 in a posture in which the display surface 7a is erected substantially perpendicular to the main surface 1a. As shown in FIG. The surface opposite to the display surface 7a side) faces the side surface 1c of the circuit board 1. Further, the terminal 7c group is bent so as to protrude to the back surface side at a substantially right angle with respect to the display surface 7a, and the distal end portion of the terminal 7c group extending along the other main surface 1b of the circuit board 1. Is soldered to a wiring pattern (not shown) provided on the main surface 1b.

  The light guide plate 6 is a molded product made of a light-transmitting resin such as acrylic, and has a recess 60 (see FIG. 4) for housing and holding the LCD cell 7. The light guide plate 6 has a flat plate-shaped first illumination portion 6a that is substantially the same shape as the display surface 7a and is directly opposed to the back surface of the LCD cell 7, and a strip-shaped first light portion that is disposed on the side of the display surface 7a. A pair of holding portions 6d and 6e for clamping the LCD cell 7 in the recess 60 from both ends in the longitudinal direction. A small hook-shaped first engaging portion 6f attached to the connecting portion 6c and engageable with the through-hole portion 1d (see FIG. 7) of the circuit board 1, and a notch portion near the side surface 1c of the circuit board 1. 1e (refer FIG. 7) and the 2nd engaging part 6g of the large hook shape which can be engaged are provided. The first engaging portion 6f and the second engaging portion 6g are located at both ends of the light guide plate 6 in the longitudinal direction. As shown in FIGS. 4 and 5, the connecting portion 6c of the light guide plate 6 has a slit 61c cut by a dimension d1 from one end side in the width direction to the other end side, and conversely, the other connecting portion 6c. A concave notch 62c is provided which is cut by a dimension d2 from the end side toward the one end side. The connecting portion 6c is locally narrowed by the slit 61c, and the depth of cut d2 of the concave notch 62c located in the vicinity of the narrow portion 63c is the width dimension of the connecting portion 6c in the narrow portion 63c. It is considered not to fall below. That is, the sum (d1 + d2) of the slit depths of the slit 61c and the concave notch 62c provided by cutting the connecting portion 6c in the opposite direction in the width direction is equal to or larger than the width dimension w of the connecting portion 6c. It is set to be.

  A light shielding plate 9 is disposed in the slit 61 c at the connecting portion 6 c of the light guide plate 6. The light shielding plate 9 is made of rubber or plastic having an outer shape as shown in FIG. 6, and the narrow portion 63c of the connecting portion 6c is inserted into the relief portion 9a cut out in a concave shape. And since the height dimension of the part arrange | positioned in the slit 61c among the light-shielding plates 9 is set equivalent to the notch depth of this slit 61c, the narrow part 63c inserted in the escape part 9a, the circuit board 1, and Thus, the light shielding plate 9 can be clamped. Moreover, as shown in FIG.2 and FIG.7, a part of light-shielding plate 9 is arrange | positioned in the position facing the back surface of the 2nd illumination part 6b.

  As described above, the connecting portion 6c of the light guide plate 6 is formed with the slit 61c and the concave notch 62c in which the sum of the cut depths is not less than the width of the connecting portion 6c, and the light shielding plate 9 is disposed in the slit 61c. Therefore, even if the green light of the light emitting element 4 leaks from the first illumination part 6a to the connecting part 6c and travels toward the second illumination part 6b, the light is mostly blocked by the slit 61c and the concave notch 62c. It will be. Similarly, even when the red light of the light emitting element 5 leaks from the second illumination part 6b to the connecting part 6c and travels toward the first illumination part 6a, the light is mostly blocked by the slit 61c and the concave notch 62c. Become. Moreover, since a part of the light shielding plate 9 is disposed at a position facing the back surface of the second illumination unit 6b, undesired light is not incident on the second illumination unit 6b via the back surface. A light shielding wall (not shown) of the case 8 is inserted between the second illumination part 6b and the holding part 6d in the vicinity thereof.

  Next, a procedure for attaching the LCD cell 7 and the light guide plate 6 to the circuit board 1 will be described. First, the LCD cell 7 and the light guide plate 6 are integrated in advance. For this integration operation, it is only necessary to press-fit the LCD cell 7 into the recess 60 of the light guide plate 6, whereby the LCD cell 7 is held between the holding portions 6 d and 6 e while facing the first illumination portion 6 a. Can do. Then, as shown in FIG. 7, after inserting the light shielding plate 9 into the slit 61c, the first engaging portion 6f of the light guide plate 6 is rotatably press-fitted into the through-hole portion 1d of the circuit board 1, and this first engagement. By rotating the light guide plate 6 in the direction in which the LCD cell 7 is close to the side surface 1c with the joint portion 6f as the rotation axis, the second engagement of the light guide plate 6 into the cutout portion 1e cut out near the side surface 1c. The portion 6g is inserted. Thus, when the second engaging portion 6g is inserted to the innermost part in the cut portion 1e, the mounting position of the LCD cell 7 with respect to the circuit board 1 is defined, and one side edge 7b of the LCD cell 7 is the side surface 1c of the circuit board 1. And the terminal 7c group overlaps the corresponding solder land (wiring pattern) on the main surface 1b. As described above, when the LCD cell 7 and the light guide plate 6 are modularized in advance, if the module product is designed to be easily assembled at a predetermined position on the circuit board 1, the assembling workability is improved.

  As described above, the LCD-equipped electronic device according to the present embodiment includes an illumination device including the light emitting elements 4 and 5 and the light guide plate 6, and the light guide plate 6 can illuminate different areas with different colors. It is like that. That is, the light guide plate 6 includes a first illuminator 6a serving as a backlight for illuminating the LCD cell 7 with green light, and a second illuminator 6b capable of illuminating the illumination area 8b near the LCD cell 7 with red light. Since it is a connected integrally molded product, the number of parts can be reduced compared to a configuration using two light guide plates in combination, the assemblability is improved, and a low-cost illumination device can be obtained.

  Further, in the light guide plate 6 of the illumination device, a slit 61c and a concave notch 62c are formed in a connecting portion 6c connecting the first illumination portion 6a and the second illumination portion 6b, and the slit 61c Since the light-shielding plate 9 is disposed in this area, when the illumination area 8b in the vicinity of the LCD cell 7 is not illuminated by the second illumination section 6b, the illumination area 8b emits light (green light) from the first illumination section 6a. There is almost no risk of being illuminated. Similarly, there is almost no possibility that light leakage (red light) from the second illumination unit 6b is mixed into the backlight of the LCD cell 7. Moreover, since a part of the light shielding plate 9 is opposed to the back surface of the second illumination unit 6b, there is no possibility that undesired light enters the second illumination unit 6b via the back surface. Therefore, light leakage that causes undesired illumination can be effectively suppressed. Since the light shielding plate 9 is sandwiched between the narrow portion 63c of the connecting portion 6c and the circuit board 1, it is not necessary to bond and fix the light shielding plate 9 or to hold it with a dedicated member.

  Further, in the electronic apparatus with an LCD according to the present embodiment example, the LCD cell 7 is attached to the circuit board 1 in a state where the one side end 7b of the LCD cell 7 in the standing posture is opposed to the side surface 1c of the circuit board 1. Therefore, compared with the case where the same LCD cell 7 is mounted on the circuit board 1 in a standing posture, the height dimension of the entire electronic device is reduced. That is, by making the side edge 7b of the LCD cell 7 in the standing posture overlap the side surface 1c of the circuit board 1, the projection height of the LCD cell 7 from the circuit board 1 is set at least by the thickness of the circuit board 1. Therefore, the height of the entire electronic device can be reduced and the thickness can be reduced without changing the size of the display surface 7a of the LCD cell 7. For the same reason, the display surface 7a of the LCD cell 7 can be enlarged without increasing the overall height of the electronic device.

  Since the LCD cell 7 has a group of terminals 7c extending from the side edge 7b to the back side at a substantially right angle, the terminal 7c group cannot be soldered to the corresponding wiring pattern of the circuit board 1. Easy. Further, since the LCD cell 7 is attached to the circuit board 1 while being held by the light guide plate 6, vibrations and impacts acting on the LCD cell 7 can be mitigated by the light guide plate 6, and the terminal 7c group The light guide plate 6 can reduce the load acting on the solder joint portion.

It is a front view of the electronic device with LCD which concerns on the example of embodiment of this invention. It is a schematic perspective view which shows the internal structure of this electronic device. It is principal part sectional drawing which shows LCD mounting structure of this electronic device. It is the principal part perspective view which looked at a part of light guide plate with which this electronic device is equipped from the back side. It is the principal part perspective view which looked at a part of this light-guide plate from the upside down direction and the front side. It is a perspective view of the light-shielding plate with which this electronic device is equipped. It is explanatory drawing at the time of attaching an LCD cell and a light-guide plate to a circuit board at the assembly process of this electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit board 2,3 Electronic component 4,5 Light emitting element 6 Light guide plate 6a 1st illumination part 6b 2nd illumination part 6c Connection part 6d, 6e Holding part 7 LCD cell 7a Display surface 7c Terminal 8 Case 8a Display window 8b Illumination area (Predetermined area)
9 Shading plate 61c Slit (notch)
62c Concave notch (notch)
63c Narrow part

Claims (5)

The first light emitting element and the second light emitting element which are mounted on the circuit board and have different emission colors, the first illumination part into which the light of the first light emitting element is introduced, and the light of the second light emitting element A light guide plate integrally formed with the second illumination unit to be introduced, and a backlight of the LCD cell mounted on the circuit board is supplied by the first illumination unit, and the LCD cell An illumination device capable of illuminating a predetermined region in the vicinity by the second illumination unit,
A first notch portion cut from the width direction one end side to the other end side of the connection portion in the connection portion connecting the first illumination portion and the second illumination portion of the light guide plate, A second cutout portion cut from the other end side of the connection portion toward the one end side, and a sum of cut depths of the first and second cutout portions is less than a width dimension of the connection portion. An illumination device characterized in that it is set to a non-value.   2. The illumination device according to claim 1, wherein one of the first and second cutout portions is a slit that locally narrows the connecting portion. 3.   The illumination device according to claim 2, wherein a light shielding plate is disposed in the slit.   4. The illumination device according to claim 3, wherein the light shielding plate is extended at a position facing the back surface of the second illumination unit.   5. The illumination device according to claim 3, wherein the light shielding plate is sandwiched between the narrow portion of the connecting portion and the circuit board. 6.

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