JP4335512B2 - Lighting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination device for product inspection that is suitably used when product inspection is performed using reflected illumination.
[0002]
[Prior art]
In this type of product inspection illumination device, a plurality of light emitters such as LEDs are arranged and illuminated so as to cover the object to be inspected from the peripheral direction so that the intensity of the inspection surface is kept uniform. Has been developed. And in order to cover a to-be-inspected object from the circumference direction, the light-emitting body mounting surface which makes | forms a curved concave surface shape, such as a cylindrical inner surface and a conical concave surface, is formed, and several LED is mounted on the light-emitting body mounting surface. It is desirable.
[0003]
For this purpose, a product inspection lighting device is conventionally subjected to a complicated process in which the holding frame itself is machined into a cylindrical inner surface or conical concave shape and perforated, and a light emitter is directly embedded in each hole and then manual wiring is performed. In order to greatly reduce the labor and cost, the inventor of the present application mounted the LED in a state where the bendable printed circuit board is kept flat, and curved the printed circuit board to make this kind of lighting device. Has been invented and patented (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-21729
[Problems to be solved by the invention]
However, in this type of lighting device, it was thought that it was extremely difficult to provide a heat dissipation structure on the back surface of the curved light emitter mounting surface. is there. Specifically, as shown in FIG. 9 , no heat radiating member is provided on the back side of the LED 100, and the air layer AS is interposed. As a result, there is still room for improvement in that it is difficult to obtain a large illumination intensity because the temperature of the LED cannot be actively lowered, and it is difficult to extend its life.
[0006]
The present invention has been made in view of such circumstances, and in a lighting device for product inspection in which a plurality of light emitters are arranged on a curved concave surface, a large illumination luminous intensity and a long lifetime are ensured while ensuring manufacturability. The main purpose is to obtain
[0007]
[Means for Solving the Problems]
That is, the present invention provides a product inspection illumination device used when a plurality of light emitters are arranged on a curved concave surface, illuminate the subject to be inspected from the surrounding direction, and use the reflected illumination to inspect the product. a is a plurality of the light emitters, chromatic and and said plurality of annular back surface resistance of the surface to be mounted is disposed a light emitter of the printed circuit board a notch in a portion a bendable in the thickness direction And a heat dissipating member that has substantially the same shape as that of the printed board in plan view and can be bent in the thickness direction, and a holding frame that holds the printed board, and the printed board is in a planar state or a substantially planar state. After holding a plurality of light emitters on the light emitter mounting surface set on one surface thereof, one notch side and the other notch side of the printed circuit board on which the light emitter is mounted are connected to the light emitter. The mounting surface is located on the concave side Bonding or holding close to each other to form the printed circuit board in a truncated conical shape, or bonding one notch side and the other notch side of the printed circuit board so that the light emitter mounting surface is located on the concave side The printed circuit board is held close to a truncated cone shape, and the light emitting body is mounted on the light emitting body mounting surface, while one cut-out side and the other cut-out side of the heat radiating member are joined or held in close proximity. The contact surface set on the concave side of the truncated cone shape is in close contact with the back surface of the light emitter mounting surface of the printed circuit board having the truncated cone shape, and the light emitting member mounting surface of the heat dissipation member Monodea the surface in close contact with the back surface is recessed so as to wrap the and the resistor has a flexible deformation is, to hold a printed circuit board equipped with the heat radiating member and the light emitters in the holding groove provided in the holding frame, the Retention In state, the heat radiating member is held groove in fits without substantially gap, which relates to a product inspection lighting apparatus characterized that you contact or substantially close contact with the bottom surface both of the back surface and holding groove of the printed circuit board.
[0008]
If this is the case, it is possible to form a truncated conical concave surface that can be brought into close contact with the anti-illuminant mounting surface simply by joining or bringing the cut-out sides of the heat radiating member together, so that it is extremely easy and reasonable. It is possible to dissipate heat from the light emitter that is disposed on this kind of curved concave surface. As a result, it is possible to dissipate the luminous body without difficulty and actively lower the temperature, so that a high illumination intensity can be obtained and the product life can be increased.
[0009]
In addition, the holding frame is simply processed into a conical concave shape for holding the printed circuit board and the heat radiating member, and there is no need to make holes for holding the light emitter embedded, so that the light emitter can be easily cut. Since it can be arranged on the concave surface of the head cone and can be wired, the manufacturing method is not complicated. Furthermore, various prefix conical concave surfaces can be easily formed by appropriately changing the size and diameter of the notches of the heat radiating member and the printed circuit board.
[0010]
On the other hand, as another embodiment that can achieve the same effect as described above, a plurality of light emitters, and a back surface of a surface that can be bent in the thickness direction and has a notch in a part thereof and on which the plurality of light emitters are mounted. An annular printed circuit board in which a resistor is disposed, a heat radiation member that has substantially the same shape as the printed circuit board in a plan view and can be bent in a thickness direction, and a holding frame that holds the printed circuit board. A heat dissipating member that has substantially the same shape as viewed and can be bent in the thickness direction is in close contact with or substantially in close contact with the back surface of the light emitting body mounting surface of the printed circuit board, The other notch side is formed in a truncated conical shape by being joined or held in close proximity so that the light emitter mounting surface is located on the concave side, and is in close contact with the back surface of the light emitter mounting surface of the heat radiating member. Flexible surface A and are those depressions to deform so as to wrap the resistor, to hold a printed circuit board equipped with the heat radiating member and the light emitters in the holding groove provided in the holding frame, in the holding state, the heat radiating member is retained in the groove And an illumination device for product inspection, characterized in that it fits in substantially without any gap and is in close contact with or substantially in close contact with both the back surface of the printed circuit board and the bottom surface of the holding groove .
[0011]
As a highly preferable mode for improving heat dissipation in implementation, a plurality of light emitters are arranged on a light emitter mounting surface having a curved surface provided in a holding frame, and the light emitter mounting A heat radiating member that can be bent in the thickness direction is brought into close contact with the back surface of the surface and the holding frame, and the surface that is in close contact with the back surface of the light emitting body mounting surface of the heat radiating member has flexibility. . This is because the heat of the luminous body can be efficiently and promptly transmitted to the holding frame via the heat radiating member so that the entire holding frame can dissipate heat. By the way, the thermal conductivity of air is 0.02 kcal / mh ° C. When a member made mainly of silicon, fluorosilicone, SEP, etc. is used as the heat radiating member, the thermal conductivity is 0.8 kcal / mh ° C. Since it becomes a grade or more, it turns out that the remarkable remarkable difference arises in the case where an air layer intervenes without using a heat radiating member, and the case where a heat radiating member is used. Furthermore, by interposing a heat radiating member, it is possible to obtain an effect that it is possible to suppress rattling and deformation of the printed circuit board.
[0012]
In addition, in order to improve the degree of adhesion and contribute to the improvement of heat dissipation, and also contribute to the ease of assembly, etc., at least the surface of the heat radiating member that is in close contact with the rear surface of the light emitter mounting surface has flexibility. It is preferable to keep it. Here, “flexibility” means that when a heat radiating member is attached, it is recessed on the back surface of the light emitter mounting surface so as to enclose parts such as lead wires and resistors protruding from the back surface of the light emitter mounting surface. That is, it is soft enough to adhere.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
[0014]
As shown in FIGS. 1 to 3, the illuminating device 4 according to the present embodiment includes a plurality of LEDs 1 that are light emitters, and a printed circuit board 2 that has an annular shape with a part of the cutout and can be bent in the thickness direction. The heat sink 6 is a heat dissipating member that has substantially the same shape as the printed circuit board 2 in plan view and can be bent in the thickness direction, and a holding frame that holds the printed circuit board 2 and has a center hole 32 for visual observation or photographing. An illumination case 3 is provided. Note that the screw 31 is provided for attaching the lighting device 4 because it is drilled in the lighting case 3.
[0015]
With such a configuration, the manufacturing method of the lighting apparatus according to the present embodiment will be described. First, after holding the printed wiring board 2 in a flat state, a plurality of LEDs 1 are implanted all over the light-emitting body mounting surface 2c set on one surface of the board 2 by a method such as soldering. Thereafter, one notch side 2a and the other notch side 2b of the substrate 2 are curved by joining or approaching so that the light emitter mounting surface 2c is located on the concave side. As a result, the printed circuit board 2 inevitably has a frustoconical shape, and the light emitter mounting surface 2c becomes a frustoconical concave surface, and the LED 1 is disposed there. At this time, the power cable 5 is also wired to the substrate 2 by soldering or the like.
[0016]
On the other hand, one notch side 6a and the other notch side 6b of the heat radiating plate 6 are joined or brought close to each other to form a truncated cone shape. Then, the close contact surface 6c set on the concave surface side of the heat radiating plate 6 is brought into close contact with the curved back surface 2d of the light emitter mounting surface 2c. Here, “contact” includes that part or all of the back surface 2d and part or all of the contact surface 6c are in close contact.
[0017]
The heat radiating plate 6 is made of, for example, silicon, fluorosilicone, SEP or the like as a main material, and has high heat conductivity and flexibility with electrical insulation. When the printed circuit board 2 is in close contact with the back surface 2d, the contact surface 6c is deformed so as to wrap around each component such as a resistor, the protruding LED 1 leg, and the like disposed on the back surface 2d. Note that a pressure-sensitive adhesive or a pressure-sensitive adhesive may be attached to the contact surface 6c to the printed circuit board 2 so that the contact surface 6c adheres to the back surface 2d.
[0018]
Thereafter, the printed board 2 on which the heat sink 6 and the LED 1 are mounted is held in a holding groove 33 having a corresponding diameter provided in the lighting case. In the present embodiment, the holding groove 33 is just large enough to accommodate the printed circuit board 2 and the heat radiating plate 6, and the heat radiating plate 6 fits in the holding groove 33 with almost no gap, and the back surface 2 d of the printed circuit board 2. In addition, it is in close contact with or substantially in close contact with both bottom surfaces of the holding grooves 33.
[0019]
Therefore, in such a case, the heat of the LED 1 can be efficiently and promptly transmitted to the holding frame 3 via the heat radiating plate 6 and can be radiated by the entire holding frame 3, so that the heat dissipation of the LED 1 can be performed without difficulty. You can go and lower the temperature positively. It becomes possible to suppress the temperature rise of LED1. As a result, high illumination intensity can be obtained, and the product life can be increased.
[0020]
Furthermore, by interposing the heat sink 6, it is possible to obtain an effect that it is possible to suppress rattling and deformation of the printed circuit board 2.
[0021]
In addition, it is possible to form a truncated conical concave surface that can be brought into close contact with the anti-light emitting body mounting surface 2d of the printed circuit board 2 simply by joining or bringing the cut-out sides 6a and 6b of the heat sink 6 together. In addition, the manufacturing process is not complicated.
[0022]
Specific effects are shown in FIGS. FIG. 7 shows the result of a comparative experiment for the red LED with and without the heat sink 6. As shown in the figure, the case where the heat sink 6 is present and the case where the heat sink 6 is not present are different from each other by about 25 ° C. in the solder portion temperature of the LED 1 20 minutes after the start of the experiment. Is approximately 10% lower than the initial light amount, whereas when there is no heat radiating plate 6, there is a significant difference of approximately 25% lower than the initial light amount.
[0023]
FIG. 8 shows the result of a comparative experiment for a white LED. In this experiment, the temperature without the heat radiating plate 6 rises to 100 ° C., which is the operation guarantee temperature of the LED. This is due to the fact that the forward voltage (VFmax) of white LED, blue LED or green LED is as high as 3.5 V and the amount of heat generation tends to increase, but there is no heat sink 6 in this way. Depending on the use conditions, it is considered that the temperature rises and causes deterioration, which has a great influence on the lifetime and the luminous intensity. Compared to this, it is understood that the temperature without the heat radiating plate 6 is kept around 45 ° C., and the temperature difference is actually 55 ° C.
[0024]
Of course, there is no need to make a hole for embedding and holding the LED on the illumination case 3 side, and the LED 1 can be easily arranged on the truncated conical concave surface 2c and can be wired easily. It can also have the effect.
[0025]
Furthermore, as shown in FIGS. 4 to 6, various prefix conical concave surfaces can be easily formed by appropriately changing the size and diameter of the notches of the heat sink 6 and the printed board 2.
[0026]
The heat sink 1 is attached to the printed circuit board 2 in advance, for example, in a flat state before the printed circuit board 2 in which the LEDs 6 are all planted is bent, and then one notch side 2a of the substrate 2 is formed. And the other cut-out side 2b are joined or brought close to each other so that the light emitter mounting surface 2c is located on the concave side, and held in a holding groove 33 having a corresponding diameter provided in the lighting case 4. I do not care.
[0032]
The present invention is not limited to the above-described embodiments, and various modifications can be made.
[0033]
For example, the light-emitting body mounting surface is not limited to a truncated conical concave surface, and may be a cylindrical inner surface or a curved concave surface similar thereto. And in that case, of course, it is necessary to make it the corresponding thing, such as making the shape at the time of making it flat form of a heat sink or a printed circuit board.
[0034]
Alternatively, the printed circuit board may be first bent into a truncated cone shape, and the LED may be mounted on the concave surface.
[0035]
Furthermore, a plurality of slits extending radially inward from the outer periphery of the printed board may be provided intermittently. With such a configuration, the printed circuit board can be bent more easily.
[0036]
Furthermore, the wiring of the printed board may be thicker than the thickness normally required according to the amount of current, and the wiring itself may have a heat dissipation function. In this way, the heat dissipation effect can be further enhanced. Specifically, it is preferable to increase the width of the wiring connected to the lead wire extending from the holding body that holds the light emitting element (bare chip) of the LED in order to efficiently dissipate heat.
[0037]
In addition, the holding frame itself is processed to form a light emitter mounting surface as in the prior art, and the heat sink and the heat dissipation member as in the above embodiment are provided on the LED mounting surface. It doesn't matter.
[0038]
In addition, the structure of each part is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.
[0039]
【The invention's effect】
As described in detail above, according to the present invention, it is possible to form a truncated conical concave surface that can be in close contact with the anti-illuminant mounting surface by simply joining or bringing the cutout sides of the heat sink together. It is very easy to dissipate heat from the light-emitting body that is disposed on this curved concave surface. As a result, it is possible to dissipate the luminous body without difficulty and actively lower the temperature, so that a high illumination intensity can be obtained and the product life can be increased.
[0040]
Of course, there is no need to drill a conical concave surface on the holding frame side, a hole for holding the light emitter embedded, etc., and the light emitter can be easily placed on the truncated conical concave surface and wired. The manufacturing method is not complicated.
[0041]
Furthermore, various prefix conical concave surfaces can be easily formed by appropriately changing the size and diameter of the notches of the heat sink and the printed circuit board.
[Brief description of the drawings]
FIG. 1 is a plan view showing a flat state of a printed circuit board on which an LED is mounted according to an embodiment of the present invention.
FIG. 2 is a plan view showing a flat plate state of the heat sink in the embodiment.
FIG. 3 is a central vertical cross-sectional view of the illumination device in the embodiment.
FIG. 4 is a plan view showing a flat state of a printed board on which an LED is mounted according to a modification of the embodiment.
FIG. 5 is a plan view showing a flat plate state of a heat sink in the modification.
FIG. 6 is a central longitudinal sectional view of a lighting device according to the modification.
FIG. 7 is experimental data (red LED) showing the effect of the present invention.
FIG. 8 is experimental data (white LED) showing the effect of the present invention.
FIG. 9 is a central longitudinal sectional view of a conventional lighting device.
[Explanation of symbols]
1. Light emitter (LED)
2 ... Printed circuit board 2a ... One notch side 2b of the board ... The other notch side 2c of the board ... Light emitter mounting surface 2d ... Back surface 6 ... Heat dissipation member (heat dissipation plate) )
6a: one notch side 6b of the heat sink ... the other notch side 6c of the heat sink ... contact surface 7 ... heat dissipation member

Claims (2)

A lighting device for product inspection used when placing a plurality of light emitters on a curved concave surface, illuminating the object to be inspected from the surrounding direction, and inspecting the product by its reflected illumination,
A plurality of light emitters, and the printed circuit board of the annular rear surface resistance is disposed in a plane and have a notch in a portion a bendable in the thickness direction is mounted a plurality of light emitters, the printed A heat dissipating member that has substantially the same shape as the substrate in plan view and can be bent in the thickness direction, and a holding frame that holds the printed circuit board, and holds the printed circuit board in a planar state or a substantially planar state, on one surface thereof After mounting the plurality of light emitters on the set light emitter mounting surface, the light emitter mounting surface is positioned on the concave side of one notch side and the other notch side of the printed circuit board on which the light emitter is mounted. In this way, the printed circuit board is formed in a truncated conical shape by being joined or held in close proximity, or one notch side and the other notch side of the printed circuit board are positioned on the concave surface side. Join or keep close After making the truncated substrate into a truncated cone shape, the luminous body is mounted on the luminous body mounting surface, while one notch side and the other notched side of the heat radiating member are joined or held in close proximity to each other. The contact surface set in the shape and on the concave surface side is closely contacted with the back surface of the light emitter mounting surface of the printed circuit board having a truncated conical shape, and the surface closely contacting the back surface of the light emitter mounting surface of the heat dissipation member There Ri Monodea deforming recess so as to wrap the and the resistor has flexibility,
The holding frame is provided with a holding groove set to a size that can accommodate the printed circuit board and the heat radiating member, and in the state where the printed circuit board with the heat radiating member and the light emitter mounted thereon is held in the holding groove, the heat radiating member is the holding groove. substantially clearance fits without close contact or substantially in close contact with the bottom surface both of the back surface and holding groove of the printed circuit board, and the light emitters illumination device for device testing, wherein Rukoto positioned outside the holding groove within. A lighting device for product inspection used when placing a plurality of light emitters on a curved concave surface, illuminating the object to be inspected from the surrounding direction, and inspecting the product by its reflected illumination,
A plurality of light emitters, and the printed circuit board of the annular rear surface resistance is disposed in a plane and have a notch in a portion a bendable in the thickness direction is mounted a plurality of light emitters, the printed A heat dissipating member that has substantially the same shape as the substrate in plan view and can be bent in the thickness direction, and a holding frame that holds the printed circuit board, and holds the printed circuit board in a planar state or a substantially planar state, A plurality of light emitters are mounted on the light emitter mounting surface set on the surface, and a close contact surface provided on one surface of the heat radiating member is in close contact with the back surface of the light emitter mounting surface, and then one of the printed circuit boards is cut. The notch side and the other notch side are joined or held close together so that the light emitter mounting surface is located on the concave side to form a frustoconical shape, and are in close contact with the back surface of the light emitter mounting surface of the heat radiating member and said surfaces has a flexible Ri deformed Monodea recess so as to enclose the anti,
The holding frame is provided with a holding groove set to a size that can accommodate the printed circuit board and the heat radiating member, and in the state where the printed circuit board with the heat radiating member and the light emitter mounted thereon is held in the holding groove, the heat radiating member is the holding groove. substantially clearance fits without close contact or substantially in close contact with the bottom surface both of the back surface and holding groove of the printed circuit board, and the light emitters illumination device for device testing, wherein Rukoto positioned outside the holding groove within.

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