JPH11220177A - Led unit and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED unit and lighting system, which is manufactured easily at low cost and with which uniformly illuminated light is obtained. SOLUTION: A plurality of LED units 20 with a U-shaped sectional slender linear cases 21, an LED mounting substrates 22, which are installed on the internal bases of the cases 21 and in which chip-type LEDs are arranged in a line shape, and Fresnel lenses 23 which are arranged in the opening sections of the cases 21 and linear in a direction along the slender straight lines of the cases are disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED unit and an illuminating device suitably used for illumination such as an automatic pattern inspection device for inspecting a defect of a pattern forming substrate.

[0002]

2. Description of the Related Art FIG. 4 shows an example of an automatic pattern inspection apparatus. FIG. 4 shows an automatic pattern inspection apparatus 40.
As shown in (a), the discriminating device 41 and the CCD camera 4
2, an optical system 43 and the like, and a pattern 52
The pattern forming substrate 50 on which is formed is irradiated with illuminating light from the illuminating device 30, an image of the pattern 52 is taken by the CCD camera 41 via the optical system 43, and the pattern 52 taken by the discriminating device 41, It is determined whether or not the pattern matches a standard pattern stored in advance, and the pattern forming substrate 50 is inspected for defects.

A lighting device 30 has a case 31 having an opening 31a in the center and a funnel-shaped mounting surface 31b on the front side, and a lamp package integrally mounted with a lens mounted on the mounting surface 31b. A ring illumination including a type LED (light emitting diode) 32 or the like is used. In the illumination device 30, a large number of LEDs 32 are arranged in order to obtain uniform illumination light without directionality, and the pattern 52 does not have a shadow when illuminating.

In this automatic pattern inspection apparatus, the image pickup area (detection area) of the CCD camera 42 is about 1 cm ² , and the area is uniformly illuminated.
Illumination light from all directions is given by the ring-shaped illumination device 30 of FIG. 2 (b) to make the pattern 52 shade, and an image is taken by the CCD camera 42 from the central opening 31a. CCD camera 42 or pattern forming substrate 50
Is moved, all the areas of the pattern forming substrate 50 can be inspected.

[0005]

However, the above-mentioned conventional lighting device has an outer diameter of 5.0 to 5.6 mm because the LED 32 is a lamp package type, and the entire device becomes large and large. I will.

[0006] Also, since the work distance is usually determined by the object to be illuminated, the mounting surface must be inclined in a funnel shape (about 30 °) so that the illuminating light is directed there. Because LED32 is attached to
Implementation was difficult.

Further, since the LED 32 is formed by integrally molding a lens, if the positional relationship between the lens and the chip is not accurate, the direction of the optical axis becomes uneven even when set on the basis of the outer shape. No illumination light was obtained.

For this reason, if the direction of the optical axis is adjusted by turning on the LEDs 32 one by one, the manufacturing cost becomes extremely high. To eliminate this unevenness,
Although it is conceivable to insert a diffusion plate on the optical path, another problem that the illumination light becomes dark occurs.

An object of the present invention is to provide an easy and inexpensive manufacturing,
Moreover, it is an object of the present invention to provide an LED unit and a lighting device that can obtain uniform illumination light.

[0010]

In order to solve the above-mentioned problems, an invention according to claim 1 is provided with an elongated linear or arc-shaped or annular case having a U-shaped cross section and an inner bottom surface of the case. L in which chip-type LEDs are arranged in a line
An LED unit including an ED mounting substrate and a Fresnel lens disposed in an opening of the case and having a long and narrow line or a circular arc or a linear line in the case.

According to a second aspect of the present invention, there is provided an illumination device using the LED unit according to the first aspect, wherein
The lighting device is characterized in that a plurality of units are arranged in the longitudinal direction and / or the width direction.

According to a third aspect of the present invention, in the lighting device using the LED unit according to the first aspect, the LED is provided.
The lighting device is characterized in that a plurality of units are arranged in a ring and / or concentrically.

[0013] The invention of claim 4 is the invention of claim 2 or claim 3.
In the lighting device described in Item 1, the LED unit is capable of adjusting an optical axis for each unit.

According to a fifth aspect of the present invention, there is provided the second to fourth aspects of the present invention.
The lighting device according to any one of the above, wherein the LED unit can be turned on for each unit.

[0015]

Embodiments of the present invention will be described below in more detail with reference to the drawings. (First Embodiment) FIG. 1 is a diagram showing a first embodiment of an LED unit according to the present invention and a lighting device using the same. The lighting device 10 is of a straight type, and has a device main body 11 provided with an irradiation port 11a, and is arranged in the device main body 11 so as to face an object O to be illuminated.
Four LED units 20-1 to 20 whose optical axes are adjusted
-4, and one LED unit 20-5 disposed on the apparatus main body 11 via the half mirror 12 so as to face the irradiation target O. The image of the target O is displayed on the center half mirror. 12 through the automatic pattern inspection device 40
(The description is omitted because it is the same as that described in FIG. 4 except that the mirror 44 is provided.)

The LED unit 20 has a rectangular parallelepiped case 21 made of aluminum or the like having a U-shaped cross section and an LED in which chip-type LEDs (light emitting diodes) are arranged in a line. Mounting board 22
And a Fresnel lens 2 which is inserted into a groove formed inside the opening of the case 21 and is linear in the longitudinal direction of the case.
And the like.

In this embodiment, the LED mounting board 22
Is mounted with 120 LED chips of 0.8 mmφ arranged at a pitch of 1.25 mm. Since many small LED chips are arranged at a narrow pitch, uniform light can be obtained. Since the LED mounting board 22 has a bare chip mounted on a printed wiring board in a planar shape by bonding, it is easy to manufacture, and since it is a chip component, it can be mounted accurately on a surface basis.

The Fresnel lens 23 is a rod (column).
It is a condenser lens equivalent to a lens, and has the advantage of being thinner and lighter than a rod lens. This lighting device 10
It is desirable to collect light from all directions into one point, but if light with a certain width is collected, the shape of a rod lens becomes larger than the width of the light, making it heavier. Would. Therefore, in the present embodiment, this Fresnel lens 23 is adopted.

In this embodiment, five 750 mm LED units 20 are used in combination. In this case,
Each LED unit 20 further extends 150 m in the longitudinal direction.
It may be divided into m LED units. In this way, it is possible to cope with lighting devices of various sizes and shapes. At this time, the Fresnel lens 23
Since the lens is a linear lens (a cylindrical lens and completely afocal on a line) along the chip mounting direction, discontinuity at a joint does not matter.

FIG. 2 is a view showing a modification of the LED unit according to the first embodiment and a lighting device using the same.
The LED units 20-1 to 20-4 may be arranged in parallel as shown in FIG. 2, depending on the object to be illuminated.

(Second Embodiment) FIG.
It is a figure showing a 2nd embodiment of an ED unit and a lighting device using the same. The lighting device 10B of this embodiment is of a ring type, in which LED units 20B-1 to 20B-3 having different radii are arranged concentrically. The internal structure of each unit 20B-1 to 20B-3 is
This is the same as the first embodiment.

Also in this case, each LED unit 20B-
1 to 20B-3 may be divided every predetermined angle (for example, every 1/4). If you do this,
Lighting control can be performed for each of the subdivided units, and can be used for the following applications.

(1) In many cases, the contrast of an image changes depending on the direction in which the illumination light is applied, and where to apply the illumination light depends on the target work. In such a case, it is possible to obtain an optimum contrast by controlling the lighting of each unit so as to irradiate the illumination light from various directions.

(2) The liquid crystal panel has spacers (particles).
To form a gap for enclosing the liquid crystal material, and the particles may be counted using the CCD camera 42 in some cases. In this case, since the sealing glass is not elementary glass but has a pattern formed, when illuminating light is irradiated from the periphery, light enters in the optical axis direction (light receiving axis direction) because it is originally a mirror surface. I won't. Since the pattern has an edge, it shines white, and it is difficult to obtain a contrast with particles.

Therefore, control may be performed so that one LED unit is turned on and the other LED unit is turned off. Note that since the pattern is formed in the 180 ° or 90 ° direction, it is sufficient to irradiate from two directions, but irradiation may be performed from three or four directions.

(3) In a chip component mounting inspection machine,
In some cases, it is inspected whether or not solder has been applied. In this case, the irradiation angle may be changed by lighting control of each unit (light is switched for illumination). The three-dimensional shape of the solder can be easily estimated by capturing images of white and invisible, depending on the irradiation angle of the lighting device.

(Modifications) Various modifications and changes are possible without being limited to the embodiment described above, and they are also within the equivalent scope of the present invention. For example, another optical system such as a prism lens may be provided integrally or separately before the Fresnel lens. In addition, the LEDs are easier to control by pulse lighting than in the case where a halogen lamp or the like is used.

[0028]

As explained in detail above, according to the present invention, there is an effect that it is easy and inexpensive to manufacture, and uniform illumination light can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of an LED unit and a lighting device using the same according to the present invention.

FIG. 2 is a view showing a modification of the LED unit according to the first embodiment and a lighting device using the same.

FIG. 3 is a view showing a second embodiment of an LED unit and a lighting device using the same according to the present invention.

FIG. 4 is a diagram illustrating an example of an automatic pattern inspection apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Illumination apparatus 11 Device main body 12 Half mirror 20 LED unit 21 Case 22 LED mounting board 23 Fresnel lens 40 Automatic pattern inspection apparatus 42 CCD camera

Claims (5)

[Claims] 1. An elongated linear, arc-shaped, or annular case having a U-shaped cross section, an LED mounting board provided on an inner bottom surface of the case, and a chip-type LED arranged in a line, An LED unit having an Fresnel lens disposed in the opening, the case being elongated in a straight line or in a direction along an arc or ring. 2. The lighting device using the LED unit according to claim 1, wherein a plurality of the LED units are arranged in a longitudinal direction and / or a width direction. 3. The lighting device using the LED unit according to claim 1, wherein a plurality of the LED units are arranged in a ring and / or concentrically. 4. The lighting device according to claim 2, wherein the LED unit is capable of adjusting an optical axis for each unit. 5. One of claims 2 to 4
The lighting device according to any one of claims 1 to 3, wherein the LED unit can be turned on for each unit.