JP2014222332A - Lcd illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LCD illumination device capable of acting as illumination for an LCD, the device which gives appropriate luminous energy in the same casing for a positive liquid crystal or a negative liquid crystal and reduces luminance unevenness.SOLUTION: An LCD illumination device 11 includes: a recessed part 39 for housing an LCD, which is provided in a main casing 33; a light source 45 for a negative LCD and a light source 47 for a positive LCD, which are alternately disposed at a predetermined interval below the recessed part 39 for housing an LCD; a first light-transmitting part 51 opened in a bottom 49 of the recessed part 39 for housing an LCD, at a position corresponding to the light source 45 for a negative LCD; a second light-transmitting part 53 opened in the bottom 49 of the recessed part 39 for housing an LCD, at a position corresponding to the light source 47 for a positive LCD; and a light-shielding part 55 provided in the second light-transmitting part 53 for blocking a part of light from the light source 47 for positive LCD, the light that is transmitted through the second light-transmitting part 53.

Description

  The present invention relates to an LCD lighting device.

2. Description of the Related Art In recent years, an automobile meter in which a liquid crystal display device is attached to a meter case is used to display various information such as a travel distance.
In such a liquid crystal display device, a backlight is used in order to improve visibility, and there are a positive display and a negative display as a display method of the liquid crystal display device using the backlight. In the positive display, light is transmitted through a portion other than the image, and in the negative display, light is transmitted through the image portion. In this case, it is preferable that the backlight does not cause luminance unevenness in an LCD (Liquid Crystal Display).

For this reason, for example, in the liquid crystal display device disclosed in Patent Document 1, the second reflecting plate is disposed between the point light source and the diffusion plate, and between the first reflecting surface disposed on the bottom surface of the housing. The light reflected repeatedly is incident on the upper diffusion plate.
In the liquid crystal display device of Patent Document 2, a light shielding film is formed in order to reduce luminance unevenness by changing the area of the transmission region.
In addition, the lighting curtain in the liquid crystal display device of Patent Document 3 includes a plurality of light shielding portions that shield part of incident light and a transmission portion that transmits incident light, and the plurality of top portions have a predetermined interval. In the formed corrugated plate shape, the light-shielding pattern of the light-shielding portion is located at each top, and is the same at a plurality of tops.

By the way, the negative liquid crystal requires a light amount, but the luminance unevenness is relatively difficult to be visually recognized. On the other hand, the positive type liquid crystal requires only a small amount of light, but the luminance unevenness is easily visible.
Therefore, as shown in FIG. 6, when illuminating the LCD with a plurality of light sources such as LEDs, when using the positive liquid crystal 501 in which the luminance unevenness is easily visible, each positive LCD is used to reduce the luminance unevenness. It is known to provide a bridge-shaped light shielding portion 505 that covers the upper portion of the light source 503. The light shielding portion 505 is provided on the bottom portion 515 of the concave LCD housing concave portion 513 of the main body case 511 provided with a locking claw 507 and an elastic biasing claw 509 around the light shielding portion 505 according to each positive LCD light source 503. On the other hand, when using a negative type liquid crystal that requires a large amount of light but is difficult to visually recognize luminance unevenness, illumination is often performed without providing the light shielding portion 505.

Japanese Patent Laid-Open No. 2004-313153 JP 2005-49664 A JP 2010-197865 A

  However, in an automobile meter, a positive type liquid crystal 501 or a negative type liquid crystal having a different display method in the same vehicle type variation may be used. In such a case, since the LCD housing structure provided in the main body case 511 differs depending on the type of LCD, it is necessary to prepare two types of main body cases 511.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide an LCD illumination that can obtain an appropriate amount of light in the same case and reduce luminance unevenness even in the case of a positive type liquid crystal or a negative type liquid crystal. It is an object of the present invention to provide an LCD illuminating device capable of achieving the above.

The above object of the present invention is achieved by the following configuration.
(1) LCD housing recesses provided in the main body case, negative LCD light sources and positive LCD light sources alternately arranged at predetermined intervals below the LCD housing recesses, and positions corresponding to the negative LCD light sources The first light-transmitting portion opened at the bottom of the LCD housing recess, the second light-transmitting portion opened at the bottom of the LCD housing recess at a position corresponding to the positive LCD light source, and the second light-transmitting portion And a light shielding part that shields part of the light of the positive LCD light source that is transmitted through the second light transmissive part.

  According to the LCD illuminating device having the configuration (1), the first light-transmitting portion that is a direct-lighting structure for negative liquid crystal and the second light-transmitting portion that includes a light-blocking portion for positive liquid crystal are alternately arranged. The LCD housing recess is provided in the main body case. When using the negative type liquid crystal, the light source for the negative LCD is turned on, and the light from the light source for the negative LCD passes through the first light transmitting portion where no light shielding portion is provided. The light passing through the first light transmitting portion is directly illuminated on the negative liquid crystal with a high light intensity, and an appropriate amount of light is obtained, thereby ensuring good visibility. On the other hand, when using the positive type liquid crystal, the light source for the positive LCD is turned on, and the light from the light source for the positive LCD passes through the second light transmitting part provided with the light shielding part. The light passing through the second light-transmitting part is partially shielded by the light-shielding part so that the light intensity is uniform and is illuminated on the positive type liquid crystal, thereby suppressing luminance unevenness. This makes it possible to share the LCD housing recess in either the positive liquid crystal or the negative liquid crystal.

(2) The LCD illumination device having the configuration of (1) above, wherein the light shielding portion is provided on an optical axis of the positive LCD light source.

  According to the LCD illuminating device having the configuration (2), it is possible to block light having a high light intensity near the optical axis of the light source for positive LCD, and the second light-transmitting portion can efficiently block light and radiate around the optical axis. It is possible evenly in the direction.

(3) The LCD illumination device having the configuration of (1) or (2), wherein the first light transmitting part is provided more than the second light transmitting part.

  According to the LCD illuminating device having the configuration (3), it is possible to easily secure the amount of light when the negative liquid crystal is used. That is, when the same main body case is shared, the first light-transmitting portion that performs illumination on the negative liquid crystal that requires a light amount compared to the positive liquid crystal is set more than the second light-transmitting portion. This makes it possible to optimally perform illumination of positive display and negative display in a single structure sharing a limited space.

(4) The LCD illumination device according to any one of the configurations (1) to (3), wherein a bottom portion and a peripheral wall portion of the LCD housing recess are formed in a substantially hemispherical shape. LCD lighting device.

  According to the LCD illumination device having the configuration (4), the light transmitted through the first light transmitting portion or the second light transmitting portion is efficiently used, and high light obtained by the basic configuration of the main body case. In addition to the utilization efficiency and luminance unevenness reduction, it is possible to further improve the light utilization efficiency and reduce the luminance unevenness.

  According to the LCD illumination device of the present invention, an appropriate amount of light can be obtained in the same case, even if it is a positive type liquid crystal or a negative type liquid crystal, and an LCD illumination with reduced luminance unevenness can be obtained.

  The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through a mode for carrying out the invention described below (hereinafter referred to as “embodiment”) with reference to the accompanying drawings. .

It is a front view of the meter for vehicles in which the liquid crystal display provided with the LCD lighting device concerning one embodiment of the present invention was attached. It is a disassembled perspective view of the liquid crystal display device shown in FIG. It is sectional drawing of the liquid crystal display device shown in FIG. FIG. 3 is a perspective view of an LCD housing recess in the LCD illumination device shown in FIG. 2. It is the perspective view which looked at the LCD accommodation recessed part of the LCD illuminating device shown in FIG. 4 from the back side. It is a disassembled perspective view of the conventional liquid crystal display device.

Embodiments according to the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the liquid crystal display device 19 provided with the LCD illumination apparatus 11 which concerns on one Embodiment of this invention can be used suitably for the combination meter 13 which is a meter for motor vehicles. The combination meter 13 is attached to an instrument panel (not shown) of the vehicle, for example. The combination meter 13 includes a speedometer 15 for instructing the vehicle speed, a liquid crystal display device 19 using a liquid crystal plate (LCD) 17, a turn L display unit 21, a turn R display unit 23, and an engine coolant temperature. Water temperature meter 25 to display, fuel meter 27, shift indicator 29, warning lamp 31 such as a seat belt non-wearing warning light, a high beam indicator light, a charging warning light, a half door warning light, a fog lamp indicator light, an engine warning light, and the like , Is provided.

  As shown in FIG. 3, these speedometer 15, liquid crystal display device 19, turn L display unit 21, turn R display unit 23, water temperature meter 25, fuel meter 27, shift indicator 29, and warning lamp 31 are included in the combination meter 13. Housed in the main body case 33. A facing 35 is attached to the front surface of the main body case 33, and the facing 35 hides the wiring board 37, the drive unit, and the like housed in the main body case 33. A front glass is attached to the front side of the main body case 33.

  The LCD 17 exposed as the liquid crystal display device 19 is housed in the LCD housing recess 39 of the main body case 33 as shown in FIG. The LCD 17 uses a negative liquid crystal or a positive liquid crystal according to the negative display or the positive display of the liquid crystal display device 19. The LCD 17 is formed in a rectangular shape, and a plurality of terminals 41 are led out on the long side. The LCD housing recess 39 is formed in a rectangular recess as a part of the main body case 33 made of a synthetic resin material. The LCD 17 is mounted so that the terminal 41 is connected to a terminal block 43 provided at the edge of the LCD housing recess 39 and covers the LCD housing recess 39.

  In the main body case 33, a wiring board 37 is disposed on the back side (lower side in FIG. 3) of the LCD housing recess 39. On the wiring board 37, a plurality of negative LCD light sources 45 and positive LCD light sources 47 are mounted alternately on a straight line. In the present embodiment, two positive LCD light sources 47 are arranged between three negative LCD light sources 45. That is, more negative LCD light sources 45 are provided than positive LCD light sources 47. In this embodiment, the negative LCD light source 45 and the positive LCD light source 47 are arranged in one row, but may be provided in a plurality of rows. Thereby, particularly when the size of the LCD 17 is large, it is easy to secure the light amount in the negative display, and it is easy to reduce the luminance unevenness in the positive display.

As shown in FIGS. 3 and 4, the negative LCD light source 45 and the positive LCD light source 47 are formed by a first light transmitting portion 51 and a second light transmitting portion 53 that are opened in the bottom 49 of the LCD housing recess 39. It is exposed inside the LCD housing recess 39.
The first light transmitting portion 51 is provided at a position corresponding to the negative LCD light source 45, and the second light transmitting portion 53 is provided at a position corresponding to the positive LCD light source 47. The three negative LCD light sources 45 and the two positive LCD light sources 47 are alternately arranged below the LCD housing recess 39 at a predetermined interval. Therefore, the first light transmitting part 51 is provided more than the second light transmitting part 53.

  The first light transmitting portion 51 of the present embodiment is formed in a substantially rectangular hole shape that is long in the direction orthogonal to the longitudinal direction of the LCD housing recess 39. The four corners are formed by chamfering or R-shape. That is, the first light transmitting portion 51 is formed as a through hole in the bottom portion 49 of the LCD housing recess 39. Therefore, the light emitted from the negative LCD light source 45 can pass through the first light transmitting portion 51 without being blocked.

  On the other hand, the second light transmitting portion 53 is provided with a light shielding portion 55. The light blocking unit 55 blocks a part of the light of the positive LCD light source 47 that is transmitted through the second light transmitting unit 53. In the present embodiment, the light shielding portion 55 is formed in a bridge shape that is long in a direction orthogonal to the longitudinal direction of the LCD housing recess 39. As shown in FIG. 5, a circular portion 57 is formed at the longitudinal center of the light shielding portion 55. In the circular portion 57, both end portions in the diameter direction protrude from the both edges of the bridge shape in a semicircular shape outward. The circular portion 57 may have other shapes such as a polygon such as a rectangle, a hexagon, and an octagon, or a shape such as an oval, a semicircle, and an ellipse. Further, the circular portion 57 and other bridge-shaped portions may be formed with through holes and slits for adjusting the light transmission amount.

The light blocking portion 55 of the present embodiment is provided so as to be positioned on the optical axis L of the light source 47 for positive LCD (see FIG. 3). More preferably, the light shielding portion 55 is provided so that the circular portion 57 is positioned on the optical axis L of the light source 47 for positive LCD. The second light transmitting portion 53 is formed in a substantially rectangular hole shape that is long in the direction orthogonal to the longitudinal direction of the LCD housing recess 39.
Therefore, as shown in FIG. 5, the second light transmitting portion 53 of the present embodiment is formed to be widened at the central portion in the longitudinal direction so that a predetermined slit 59 is formed between the circular portion 57. Is done. Then, by appropriately setting the width of the slit 59 of the second light transmitting portion 53, the emitted light from the positive LCD light source 47 that has passed through the slit 59 causes uneven brightness on the LCD 17 of the positive liquid crystal. It is configured so that it is possible to perform illumination with uniform light intensity that is difficult.

  Furthermore, the bottom 49 and the peripheral wall 61 of the LCD housing recess 39 according to the present embodiment are formed in a substantially hemispherical shape. The bottom portion 49 and the peripheral wall portion 61 having a substantially hemispherical shape function as a reflector. That is, light emitted from the negative LCD light source 45 or the positive LCD light source 47 and incident on the reflector portion is efficiently reflected toward the negative liquid crystal or positive LCD 17.

Next, the operation of the LCD illumination device 11 having the above configuration will be described.
In the LCD illumination device 11 according to the present embodiment, as described above, the first light-transmitting portion 51 having a direct illumination structure for negative liquid crystal and the second light-transmitting portion 53 including the light-blocking portion 55 for positive liquid crystal. LCD housing recesses 39 are alternately provided in the main body case 33.

  When using negative type liquid crystal for the LCD 17, the negative LCD light source 45 is turned on, and the light from the negative LCD light source 45 passes through the first light transmitting portion 51 where the light shielding portion 55 is not provided. The light passing through the first light transmitting portion 51 is directly illuminated on the negative liquid crystal LCD 17 with high light intensity, and an appropriate amount of light is obtained, thereby ensuring good visibility in negative display.

  On the other hand, when positive type liquid crystal is used for the LCD 17, the positive LCD light source 47 is turned on, and light from the positive LCD light source 47 passes through the second light transmitting part 53 provided with the light shielding part 55. The light passing through the second light transmitting part 53 is partially shielded by the light shielding part 55 so that the light intensity becomes equal and illuminated on the LCD 17 of the positive type liquid crystal, and uneven brightness in the positive display is suppressed. Thereby, the LCD illumination device 11 can share the LCD housing recess 39 regardless of whether the LCD 17 is a positive type liquid crystal or a negative type liquid crystal.

  Further, in the LCD illumination device 11 of the present embodiment, light having a strong light intensity near the optical axis L of the light source 47 for positive LCD can be shielded, and the light shielding in the second light transmitting portion 53 is efficient and the center of the optical axis L It becomes possible evenly in the radiation direction.

  Further, in the LCD illumination device 11 of the present embodiment, it is possible to easily secure the amount of light when the negative type liquid crystal is used for the LCD 17. That is, in the case where the same main body case 33 is shared, the first light-transmitting portion 51 that illuminates the LCD 17 of the negative liquid crystal that requires a light amount as compared with the positive liquid crystal is more than the second light-transmitting portion 53. There are also many settings. As a result, in a single structure sharing a limited space, illumination of positive display and negative display can be optimally performed.

  Further, in the LCD illumination device 11 of the present embodiment, the reflector 49 is configured by the bottom portion 49 and the peripheral wall portion 61 that are substantially hemispherical, so that the first light transmitting portion 51 or the second light transmitting portion 53 is transmitted. Light will be used efficiently. Thereby, in addition to the high light utilization efficiency and luminance unevenness obtained by the basic configuration of the main body case 33, it is possible to further improve the light utilization efficiency and reduce the luminance unevenness.

Therefore, according to the LCD illumination device 11 according to the present embodiment, even if the LCD 17 is a positive type liquid crystal or a negative type liquid crystal, an appropriate amount of light can be obtained with the same main body case 33, and the LCD illumination with reduced luminance unevenness can be obtained. It becomes possible to do.
In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimensions, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

11 ... LCD lighting device 17 ... LCD
33 ... Main body case 39 ... LCD housing recess 45 ... Negative LCD light source 47 ... Positive LCD light source 49 ... Bottom 51 ... First light transmitting portion 53 ... Second light transmitting portion 55 ... Light shielding portion 61 ... Peripheral wall portion

Claims (4)

LCD housing recess provided in the body case;
A negative LCD light source and a positive LCD light source alternately disposed at predetermined intervals below the LCD housing recess;
A first light-transmitting portion opened at the bottom of the LCD housing recess at a position corresponding to the negative LCD light source;
A second translucent part opened at the bottom of the LCD housing recess at a position corresponding to the positive LCD light source;
A light-shielding part that is provided in the second light-transmissive part and shields part of the light of the positive LCD light source that transmits the second light-transmissive part;
An LCD illumination device comprising:   2. The LCD illumination device according to claim 1, wherein the light shielding portion is provided on an optical axis of the positive LCD light source.   3. The LCD illumination device according to claim 1, wherein the first light-transmitting portion is provided more than the second light-transmitting portion.   The LCD illumination device according to any one of claims 1 to 3, wherein a bottom portion and a peripheral wall portion of the LCD housing recess are formed in a substantially hemispherical shape.

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