JP5283005B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device that emits line-shaped light having excellent color mixing properties.

  2. Description of the Related Art Conventionally, there is known an illuminating device that mixes light of a plurality of colors emitted from a color LED using a light guide plate and emits white light from a light guide surface of the light guide plate (see Patent Document 1). As shown in FIGS. 5 and 6, the basic configuration of such an illuminating device includes a red LED 14 </ b> R, a green LED 14 </ b> G and a blue LED 14 </ b> B arranged in a row, and a transparent light guide plate 12. The emitted light is introduced from one end surface 121 of the light guide plate 12 and is repeatedly reflected and diffused in the light guide plate 12 to mix red light, green light, and blue light to obtain white light, which is supplied to the light guide plate 12. It is derived from the other end surface 122 of the.

JP 2009-218175 A

  However, for example, in the lighting device 10 having the configuration shown in FIGS. 5 and 6, red and blue are dominant in the vicinity of both ends 124 and 125 in the longitudinal direction of the light guide plate 12 in the vicinity of the longitudinal ends 124 and 125, respectively. Light is derived. As shown in FIG. 7, the LED rows are symmetrically arranged on the inner side surfaces 123a and 123b of the light guide plate 12 with the boundary lines 126a and 126b between the inner side surfaces 123a and 123b and the base end inner surface 121 ′ as symmetry axes. Therefore, two red LEDs 14R are arranged in succession when the left boundary line 126a is sandwiched in FIG. 7, while two blue LEDs 14B are disposed when the right boundary line 126b is sandwiched in FIG. This is because the light of a specific color emitted from the continuously arranged LEDs 14 is enhanced near both ends 124 and 125 in the longitudinal direction of the light guide plate 12 in the plan view. For this reason, the light derived from the vicinity of both ends 124 and 125 in the longitudinal direction of the light guide plate 12 is predominantly red or blue.

  The present invention has been made in view of such a problem, and it is a main intended object to provide an illumination device capable of emitting mixed color light sufficiently mixed from an end portion of a lead-out plate. It is.

  That is, the lighting device according to the present invention includes a plurality of LEDs arranged in one or a plurality of rows, a light source portion in which two kinds of LEDs are alternately arranged in one row, and a base end portion of the light source portion. Arranged so as to face a plurality of LEDs arranged in one or a plurality of rows, introducing light emitted from the light source part from the base end part and leading out from a front end part facing the base end part, A transparent solid or hollow plate-shaped light guide part whose inner peripheral surface is a reflective surface, and at least one end in the longitudinal direction of the inner peripheral surface base edge of the plate-shaped light guide part is It is located on the substantially optical axis of LED arrange | positioned at the end of the LED row | line | column of a light source part.

  In such a case, in the extending direction of the LED row, two LEDs of a specific color are not continuously arranged across the boundary line between the inner surface of the light guide plate and the inner surface of the base end. In the vicinity of the end in the longitudinal direction of the planar view, the light of the specific color is not enhanced and becomes dominant, and the mixed color light that is sufficiently mixed can be derived from the vicinity of the end in the longitudinal direction of the light guide plate. .

  Among the lighting devices according to the present invention, for emitting white light, for example, when the light emission intensity of the green LED is lower than that of the red LED or the blue LED, the light source unit includes two LED rows, Preferably, red LEDs and green LEDs are alternately arranged in one column, and green LEDs and blue LEDs are alternately arranged in the other column.

  In the above aspect, in order to enhance the color mixing effect, the green LEDs arranged in two different rows are not adjacent to each other in the direction orthogonal to the extending direction of the LED rows, and the green LEDs are staggered. A mode in which the two are aligned is preferable.

  According to the present invention having such a configuration, it is possible to emit line-shaped light having excellent color mixing properties.

The typical perspective view of the illuminating device which concerns on one Embodiment of this invention. The top view of the illuminating device which concerns on the same embodiment. The schematic diagram at the time of seeing the inside of the light-guide plate in the same embodiment from upper direction. The schematic diagram of the illuminating device which concerns on other embodiment. The typical perspective view of the conventional illuminating device. The top view of the conventional illuminating device. The schematic diagram at the time of seeing the inside of the light-guide plate of the conventional illuminating device from upper direction. FIG.

  An embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIGS. 1 and 2, the lighting device 1 according to the present embodiment includes a light guide plate 2 and a light source unit 3 that emits light toward a base end surface 21 of the light guide plate 2.

Each part will be described in detail.
The light guide plate 2 is made of, for example, a resin having a transparent solid rectangular parallelepiped shape. The light guide plate 2 has a base end surface 21 as a light introduction surface and a tip surface 22 opposite to the light introduction surface. The inner peripheral surfaces 23a to 23d of the light guide plate 2 play a role as reflecting surfaces that totally reflect light, and light introduced from the base end surface 21 is communicated with the outside by the inner peripheral surfaces 23a to 23d of the light guide plate 2. The light is totally reflected by the refractive index difference and is reflected and mixed, and proceeds toward the tip surface 22 with almost no loss, and is derived from the tip surface 22.

  The light guide plate 2 is held so as to be positioned on the optical axis of the LED 4 by a holding member 6 mounted on a wiring board 5 described later, and almost all of the light spreading outward from the optical axis of the LED 4 by a predetermined angle or more is transmitted. Install inside.

  The light source unit 3 includes red LEDs 4R that emit red light, green LEDs 4G that emit green light, and blue LEDs 4B that emit blue light. In this embodiment, light is emitted from a light emitting portion 4a formed at the center of the top surface. A chip type chip having a flat rectangular parallelepiped shape is used. These color LEDs 4 are arranged such that the light emitting portions 4a are arranged in a straight line at a predetermined interval on a strip-like flat wiring board 5 as a unit substrate, and two types of LEDs 4 are alternately arranged in each row. In addition, a plurality of rows are arranged in two rows. More specifically, as shown in FIG. 2, a plurality of red LEDs 4R and green LEDs 4G are alternately arranged from the left side toward one row 31 with a predetermined interval. From the left side, a plurality of green LEDs 4G and blue LEDs 4B are alternately arranged at predetermined intervals. Each LED 4 is disposed so as to face the base end face 21 of the light guide plate 2, and light emitted from the LED 4 enters the light guide plate 2 from the base end face 21.

  The red light, green light, and blue light emitted from each LED 4 are repeatedly reflected between the inner side surfaces 23c and 23d facing each other mainly in the direction orthogonal to the longitudinal direction of the light guide plate 2 and sufficiently diffused. After being mixed, it is led out from the tip surface 22. For this reason, line-shaped white light is emitted from the front end surface 22 of the light guide plate 2. The green light LED 4G used in the present embodiment has a light emission intensity lower than that of the red light LED 4R and the blue LED 4B. But green light won't prevail. However, the green LEDs 4G arranged in two different rows are staggered so as not to be adjacent to each other in the direction perpendicular to the extending direction of the LED rows so that the green light is locally enhanced and color unevenness does not occur. Are listed.

  When the illumination device 1 is viewed from above, as shown in FIG. 2, both ends 24 and 25 in the longitudinal direction of the light guide plate 2 are substantially on the optical axes of the LEDs 4 disposed at both ends of the row. The light emitting portions 4a of the LEDs 4 disposed at both ends of the row are substantially half facing the base end face 21 of the light guide plate 2, but the other half is light guide plate 2 in the longitudinal direction in plan view. It protrudes from both ends 24 and 25 of the.

  In the illuminating device 1 having such a configuration, when the inside of the light guide plate 2 is viewed from the front end surface 22, the inner side surfaces 23 a and 23 b of the light guide plate 2 are connected to the inner side surfaces 23 a and 23 b as shown in FIG. 3. The rows of LEDs 4 appear symmetrically with respect to the boundary lines 26a and 26b with the base inner surface 21 ', but only about half of the LEDs 4 arranged at both ends of the row appear, so there are two LEDs of a specific color. When the LED 4 reflected on the inner side surfaces 23a and 23b and the LED 4 visible from the proximal end inner surface 21 'are viewed together, the two types of LEDs 4 are stretched while maintaining the alternately arranged state. Looks like you are.

  For this reason, in the illuminating device for inspection 1 according to the present embodiment, the light of a specific color is not enhanced and predominates at both ends 24 and 25 of the light guide plate 2, so both ends 24 and 25 of the light guide plate 2. From the above, it is possible to derive sufficiently mixed white light.

  In the direction perpendicular to the longitudinal direction of the light guide plate 2 in plan view, the entire LED 4 is reflected on the inner side surfaces 23c and 23d with the boundary line between the inner side surfaces 23c and 23d and the base end inner surface 21 'as the axis of symmetry. Two LEDs 4 of the same type are arranged in succession across the line, but light is repeatedly reflected between the inner side surfaces 23c and 23d facing each other in the direction perpendicular to the longitudinal direction of the light guide plate 2 in plan view. Since it is made uniform, the light of a specific color is not enhanced even if LEDs 4 of the same type are continuously arranged.

  The present invention is not limited to the above embodiment.

  For example, a light diffusing plate may be disposed on the front end surface 22, and the luminance of light derived from the front end surface 22 may be made uniform. As such a light diffusing plate, for example, the surface of the light-transmitting substrate is provided with irregularities by embossing or embossing or the like, and the surface is configured as a frosted glass surface, or white paint is provided on the surface of the light-transmitting substrate. A variety of materials imparted with light diffusibility using light scattering, such as those coated with a gap between them and particles containing light scattering particles in a light transmissive substrate, can be used.

  As shown in FIG. 4, a pair of light guide plate 2 and light source unit 3 are used as units, and a plurality of units are connected in series in the longitudinal direction in plan view, and one lighting device 1 is formed by the plurality of units. It may be configured. At this time, in order to configure one lighting device by connecting a plurality of the same units, it is necessary to provide a plurality of LEDs 4 in the longitudinal direction in one light source unit 3 as shown in FIG. In addition, each light source unit 3 needs to be shorter than the light guide plate 2 on the other end side (right end in FIG. 4) by the amount protruding from one end side (left end in FIG. 4) of each light guide plate 2. is there. For this reason, in the illuminating device 1 shown in FIG. 4, the joining end of adjacent light-guide plates 2 will be located on the optical axis of LED4 arrange | positioned at the left end of the light source part 3 of the right unit toward it.

  In this way, by connecting a plurality of units including the pair of light guide plates 2 and the light source unit 3 to form a single lighting device 1, even if a failure occurs in any of the units, the unit can be replaced in units. Thus, the maintenance cost can be reduced. At this time, as shown in FIG. 4, the front end surface 22 of the light guide plate 2 of each unit is covered with a single long light diffusion plate 27 to eliminate variations in the intensity of light derived from each unit. Is preferably achieved.

  The plate-shaped light guide part may not be a transparent solid light guide plate, but may be a cylindrical body having an outer appearance rectangular parallelepiped shape whose inner peripheral surface is a reflective surface. As such a cylindrical body, for example, the inner surface is coated with a white paint, the inner surface is plated with silver, aluminum, gold or the like metal to make a mirror surface, the inner surface is subjected to electrolytic polishing to a mirror surface And the like.

  The LED used when the illumination device according to the present invention emits white light is not limited to the red LED, the green LED, and the blue LED, and the combination of the red LED and the green LED in one row The green LED and the blue LED are not limited to a mode of being arranged in the other row. For this reason, for example, a plurality of blue LEDs and yellow LEDs that emit yellow light may be alternately arranged in one row, and two types of white LEDs that emit white light having different color temperatures are alternately 1 A plurality of columns may be provided side by side. Furthermore, the number of LED rows is not limited to two, and may be one or more.

  In addition, the present invention is not limited to the above-described embodiments, and may be configured by appropriately combining some or all of the various configurations described above without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Illuminating device 2 ... Light guide plate 21 ... Base end surface 22 ... Front end surface 23 ... Inner peripheral surface 3 ... Light source part 4 ... LED

Claims (3)

A light source unit including a plurality of LEDs arranged in one or a plurality of rows on a strip-shaped flat wiring board , and two types of LEDs arranged alternately in one row;
A proximal end is disposed so as to face the plurality of LEDs arranged in one or a plurality of rows, and introduces light emitted from the light source from the proximal end and faces the proximal end Derived as line-shaped light from the part, the longitudinal direction and the optical axis direction are sufficiently large with respect to the width direction, and the dimensions in each direction are the longitudinal direction, the optical axis direction, and the width direction in order from the largest, A transparent solid or hollow plate-shaped light guide portion whose peripheral surface is a reflective surface, and
At least one end in the longitudinal direction of the inner peripheral surface base end edge of the plate-like light guide part is located on the substantially optical axis of the LED disposed at one end of the LED row of the light source part. A lighting device. The light source section has two LED rows, one row is alternately arranged with red LEDs and green LEDs, and the other row is alternately arranged with green LEDs and blue LEDs. The illumination device according to claim 1, wherein the illumination device is used for inspection .   The lighting device according to claim 2, wherein the green LEDs arranged in two different rows are not adjacent to each other in a direction orthogonal to the extending direction of the LED rows.