JPH08178852A - Lighting device for inspection - Google Patents

Abstract

PURPOSE: To obtain a lighting device for obtaining a state illuminance using a fluorescent lamp by forming an air flow in an air duct by a ventilation machine and cooling a cooling plate facing the air duct. CONSTITUTION: A cooling plate 1 and a fluorescent lamp 5, fixed to the cooling plate 1 are retained by a retaining plate 6. Two fans 10 and 11 (either of them becomes an exhaust fan) constituting a ventilation machine are fixed to the retaining plate 6. The temperature of the surrounding atmosphere of the fluorescent lamp 5 is detected by a temperature sensor 13. When the atmosphere temperature exceeds a specific value, the exhaust fan is activated and an air flow for cooling is formed in an air duct 12. At this time, an air suction fan is at a halt, but air is sucked through the air suction fan. The cooling plate 1 is cooled by the air flow and the surrounding atmosphere of the fluorescent lamp 5 is indirectly cooled by the cooling plate 1. When the atmospheric temperature is further increases, the air suction fan as well as the exhaust fan are actuated and air is pressed into the air duct 12 by the air suction fan, thus increasing the amount of air flowing through the air duct 12 and increasing the amount of heat radiated from the cooling plate 1 and decreasing the atmospheric temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination device for optically inspecting an object, and more particularly to a device suitable for using a fluorescent lamp as a light source.

[0002]

2. Description of the Related Art As an illuminating device for photographing and inspecting an object with a video camera, a fluorescent lamp is provided in the box and a light diffusion plate is provided on one surface of the box. The box is provided with a ventilation port to handle the temperature rise of the fluorescent lamp. The inspection is performed by comparing the brightness levels of images obtained by capturing reflected light or transmitted light from an illuminated object.

[0003]

However, in the above-described ventilation port type lighting device, when cold air that has entered the installation atmosphere due to opening and closing of the door is sucked into the lighting device, the temperature inside the box suddenly increases. As the illuminance decreases,
It has a problem that it interferes with the inspection.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inspection illuminating device using a fluorescent lamp to obtain a stable illuminance.

[0005]

In order to achieve the above-mentioned object, the present invention provides a box, one surface of which is a heat dissipation plate, and a surface opposite to the heat dissipation plate is a light diffusion plate, and the heat dissipation plate is installed inside the box. The present invention is characterized in that it comprises a fluorescent lamp, an air passage installed outside the box with the heat radiating plate as one surface, and a ventilator installed at an end of the air passage.

[0006]

According to the present invention, since the air flow is formed in the air passage by the ventilator and the heat dissipation plate facing the air passage is cooled, the ambient atmosphere of the fluorescent lamp is indirectly cooled by the heat dissipation from the heat dissipation plate. To be done. Since the blower is operated and stopped by the signal from the temperature detector, the ambient temperature around the fluorescent lamp installed in the box is maintained at an appropriate temperature for the fluorescent lamp.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the inspection illumination device according to the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view of the inspection illumination device, and FIG. 2 is a plan view of the inspection illumination device. In FIGS. 1 and 2, reference numeral 1 is a heat radiating plate, and a light diffusing plate 2 is installed facing the heat radiating plate 1. Side plates 3 are formed on the four surfaces of the heat radiating plate 1 above, below, left and right,
The heat dissipation plate 1, the light diffusion plate 2 and the side plate 3 form a box 4. A plurality of fluorescent lamps 5 are arranged in the box 4, and these fluorescent lamps 5 are fixed to the heat dissipation plate 1.

A holding plate 6 is installed outside the box 4 so as to face the heat dissipation plate 1. The holding plate 6 has 4
A side plate 7 is formed on the surface, and an outer box 8 is formed by the holding plate 6, the side plate 7 and the light diffusing plate 2. The light diffusing plate 2 constitutes one surface common to the box 4 and the outer box 8. Further, the holding plate 6 of the outer box 8 and the heat radiating plate 1 of the box 4 are connected by the connection fittings 9, and the heat radiating plate 1 and the heat radiating plate 1 are connected.
A fluorescent lamp 5 attached to the is held by a holding plate 6.

The holding plate 6 constitutes a ventilator 2.
The individual fans 10 and 11 are fixed. One of the two fans 10 and 11 constitutes an exhaust fan, and the other fan constitutes an intake fan,
These fans 10 and 11 form an air flow for cooling in an air passage 12 defined between the heat dissipation plate 1 and the holding plate 6. The fans 10 and 11 are arranged at the ends of the air passage 12. A temperature sensor 13 for detecting the temperature of the ambient atmosphere of the fluorescent lamp 5 is installed inside the box 4 so that the fans 10 and 11 can be operated and stopped by a signal from the temperature sensor 13. Has become.

Next, the operation of the inspection illuminating device configured as described above will be described. The temperature of the ambient atmosphere of the fluorescent lamp 5 is detected by the temperature sensor 13. When the ambient temperature exceeds a predetermined value, the exhaust fan operates and a cooling air flow is formed in the air passage 12. At this time, the intake fan is stopped, but air is sucked in from the intake fan. Since the heat sink 1 is cooled by this air flow, the atmosphere around the fluorescent lamp 5 is indirectly cooled by the heat sink 1.

When the ambient temperature further rises, the intake fan operates in addition to the exhaust fan, and the air is pushed into the air passage 12 by the intake fan, so that the amount of air flowing through the air passage 12 increases. As a result, the amount of heat radiated from the heat radiating plate 1 is increased and the ambient temperature is lowered. In the embodiment shown in FIGS. 1 and 2, an example in which an exhaust fan and an intake fan are installed as a ventilator has been described, but only the exhaust fan may be installed.

[0012]

As described above, according to the present invention, cold air is not directly sucked into the box accommodating the fluorescent lamp, and the ambient atmosphere of the fluorescent lamp is indirectly connected via the heat sink. Since it is cooled, the ambient atmosphere of the fluorescent lamp is kept in an appropriate temperature range. Therefore, a stable illuminance can always be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an inspection illumination device according to the present invention.

FIG. 2 is a plan view showing an embodiment of the inspection illumination device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat sink 2 Light diffusion plate 4 Box 5 Fluorescent lamp 6 Holding plate 8 Outer box 10, 11 Fan 12 Wind path 13 Temperature sensor

Claims (2)

[Claims] 1. A box in which one surface is a heat dissipation plate and a surface facing the heat dissipation plate is a light diffusion plate, a fluorescent lamp installed in the heat dissipation plate inside the box, and a heat dissipation plate as one surface installed outside the box An illumination device for inspection, which comprises an air passage that is provided and an air blower installed at an end of the air passage. 2. The inspection lighting device according to claim 1, wherein the blower is operated and stopped according to a signal from a temperature detector installed inside the box.