JPH1039426A - Original illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the rising of temp. in trigger band parts and to prevent the shortening of the life of joining caused by a thermal shock by locating lamp cooling blowing paths on the same radial, so that the blowing paths face the lamp trigger band parts. SOLUTION: Both end parts of a circular-arcuate curved tube lamp are fixed in supporting grooves 30 located in both end parts of a lamp holder 12. Further, five grooves (blowing paths) 31a-31e are radially formed from the center of curvature O of the curved tube lamp, on the front surface of the lamp holder 12. The respective grooves 31a-31e communicate with a blowing part 15. Therefore, cooling air from a fan is discharged to the curved tube lamp through each groove from the blowing part 15. Then, trigger electrode wires 32 are additionally provided in the curved tube lamp and held by bands 33a-33e. Further, the outside-diameter side end parts (an exit for the cooling air) of the grooves (blowing paths) 31a-31e are arranged at intervals of 45 deg., so as to just face the bands 33a-33e, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile machine, and the like.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document illuminating device used in a document reading apparatus, and more particularly, to an improvement in a cooling method of a lighting device using an arcuate curved tube lamp.

[0002]

2. Description of the Related Art A reading section of an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile apparatus, and a document reading apparatus use a document reflecting light obtained by irradiating a document on a contact glass with light to obtain image information. To perform image formation, image processing, and the like. A document illuminating device used in these devices is a combination of a light source, a mirror, a lens, and the like. Incidentally, Japanese Patent Application Laid-Open No.
Japanese Patent Application Laid-Open No. 170929/1989 discloses an illumination device using an arcuate curved tube lamp and a cooling means therefor. In this document illuminating device, a plurality of grooves for blowing cooling air to the lamp are radially arranged at the center of the curvature of the curved tube lamp to cool the lamp. However, this conventional example has the following problems. 1. The air passage composed of the grooves is arranged radially with respect to the center of curvature of the curved tube lamp, but is provided at predetermined intervals to hold the trigger electrode (line) provided along the curved tube lamp. Since the direction of air flow is not set so as to cool each wound band, the temperature rise of the lamp located in the band cannot be suppressed, and as a result, the thermal shock to the weld joint of the band increases. As a result, the life is shortened. 2. Cooling air blown toward the lamp from the air passage becomes less likely to come out of the light-shielding plate (a plate surrounding the lamp etc. to shield light leaked from the lamp). As a result, the cooling efficiency is deteriorated by swirling, and the life of the lamp electrode and the trigger electrode wire is apt to rapidly deteriorate. 3. When an exhaust port is provided on a light-shielding plate located on the extension of the ventilation path of the ventilation path formed of radially arranged grooves in the ventilation direction, one of the direct light from a lamp located between the ventilation path and the ventilation port is provided. Part leaks from the air outlet and reaches the contact glass,
This affects the function of irradiating the original and causes the quality of the read image and the formed image to deteriorate.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and when a plurality of air passages (grooves) are arranged radially with respect to the center of curvature of a curved tube lamp, the lamp is wound around the lamp. Of the life of the lamp due to the cooling failure of the band for holding the trigger electrode, and the cooling air blown from the ventilation path to the lamp is prevented from staying in the light shielding plate, thereby preventing the cooling efficiency from decreasing. It is still another object of the present invention to provide a document illuminating device capable of preventing deterioration of image quality due to leakage of lamp light from an air outlet provided in a light shielding plate.

[0004]

In order to achieve the above object, according to the first aspect of the present invention, an upper surface portion of a housing is formed of a contact glass, and is mounted on the contact glass in the housing. A plurality of arcuate curved lamps for illuminating a document are arranged, and a plurality of air passages arranged radially to blow cooling air from the center of curvature of the curved lamp toward the curved lamp; and And a light-shielding plate disposed above the curved tube lamp to prevent direct light from the curved tube lamp from reaching the contact glass. , Characterized in that the trigger electrode band of the curved tube lamp is positioned. According to a second aspect of the present invention, an exhaust port is formed on the surface of the light shielding plate located on an extension of the outlet of the air passage. The invention according to claim 3 is characterized in that an eave-shaped light-shielding plate is protrudingly provided on an upper outer side of an exhaust port of the light-shielding plate.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the accompanying drawings. FIGS. 1, 2 and 3 are an overall longitudinal sectional view, a cross-sectional view of a main part, and a perspective view of a main part structure showing a configuration of an embodiment of the present invention. The document illuminating device shown in FIG. 1 includes a curved tube lamp 1 composed of a flash lamp, a reflecting mirror 2 located below the lamp, a contact glass 3 arranged on the upper surface of the housing for mounting a document 4, A reflector 5 arranged directly above the curved tube lamp 1;
A light shielding plate 6 located above the reflection shade 5 and a scale 7
, Upper base 8, lower base 10, lamp stand 11, lamp holder 12, inner cover 13
, Duct 14, blower 15, lamp cover 16
, A stay 17, a wall plate 18, and packings 19 and 20. In the above configuration, the light beam emitted from the curved tube lamp 1 is reflected by the reflecting mirror 2 and irradiates the original 4 on the contact glass 3. The illuminated document image is projected onto a photoreceptor by an image forming means including a lens. At a position near the curved tube lamp 1, there is disposed a reflection shade 5 having a reflection surface for returning irradiation light from the curved tube lamp 1 to the curved tube lamp in a direction corresponding to the reflecting mirror 2. A light-shielding plate 6 is arranged to prevent direct light from reaching the original. The reflecting mirror 2 is fixed to a lower base 10 of an illumination system, a lamp stand 11 is fixed to the lower base 10, and a lamp holder 12 for holding the curved tube lamp 1 is held on the lamp stand 11 in an adjustable manner. I have. An inner cover 13 is attached to the opening of the upper base 8 and the lower base 10 on the side of the light source 1 to protect the light source.
A duct 14 is arranged on the inner cover 13, and the air blowing part 15 of the lamp holder 12 and the end of the duct 14 coincide with each other when the inner cover is set to form a light source cooling air blowing path. The light source cooling air supply path includes an air supply unit 15 of the lamp holder 12, a lamp cover 16, a duct 14, and the like. The air sent through these parts is blown toward the light source 1.

As shown in FIGS. 2 and 3, an arc-shaped curved tube lamp 1 has support grooves 30 located at both ends of a lamp holder 12.
Both ends are fixed inside. Assuming that the center of curvature of the curved tube lamp 1 is a point O, five grooves (blowing paths) 31 a to 31 e are formed on the upper surface of the lamp holder 12 radially from the point O. Each of the grooves 31 a to 31 e communicates with the blower 15. Accordingly, cooling air from a fan (not shown) is discharged from the blower unit 15 to the curved tube lamp through each groove. As shown in FIG.
2, and each trigger electrode line 32 is held by bands 33a to 33e arranged at intervals of, for example, 45 degrees. Trigger electrode wire 32 and band 33a
To 33e are fixed by welding. In the present invention, the outer diameter side ends (the outlets of the cooling air) of the grooves (blowing passages) 31a to 31e are arranged at intervals of 45 degrees so as to face the respective bands 33a to 33e. Here, the 45-degree interval is merely an example, and the grooves may be arranged corresponding to the band arrangement intervals.

As described above, according to the first aspect of the present invention, the bands 33a to 33 for fixing the trigger wire 32 of the curved tube lamp 1 are provided.
With respect to e, grooves 31a to 31e, which are ventilation paths to the lamp 1, are formed radially around the point 0 so that wind from a fan (not shown) directly hits the bands 33a to 33e and the lamp. As a result, the rise in the temperature of the band portion is suppressed, and the deterioration of the bonding strength life can be greatly delayed as compared with the related art. Next, in the invention of claim 2,
As shown in FIGS. 2, 5 and 6 (b), bands 33a to 33a to fix the trigger wire 2 of the curved tube lamp 1 around the point 0 are used.
33e, and grooves 31a to 31 which are air passages to the lamp
Openings (exhaust ports) 40a to 40e are provided on the surface of the light-shielding plate 6 located on the same radiation as e. With this configuration, the flow of the cooling air flows more smoothly than in the case where the opening is not formed as shown in FIG. It is possible to prevent deterioration of the bonding life between the lamp electrode and the trigger band. That is, in the case of FIG. 6 (a), the grooves 31a to 31e
Although the cooling effect was insufficient because the wind from the stagnation as shown by the arrow, if the openings were provided as shown in FIG. 6 (b), the wind from each groove would flow along the outer periphery of the lamp 1. Since the air is smoothly exhausted from the opening after passing through, the cooling effect is enhanced.

Next, as shown in FIGS. 2 and 5, the invention according to claim 3 is an eave-like reflecting plate 50a-50e extending outward from the upper edge of the opening 40a-40e of the light shielding plate 8. Is provided. Further, as shown in FIG. 5, the lengths and installation positions of the reflectors 50a to 50e are adjusted so as not to enter the image area, so that the direct light from the lamp 1 does not reach the original. . That is, as described above as a drawback of the conventional example, when the air outlet is provided on the light shielding plate which is conventionally positioned on the air blow direction in the air blow path formed of grooves arranged radially, the air blow path and the air blow Some of the direct light from the lamp located between the air outlet and the air outlet leaks from the air outlet to reach the contact glass, affecting the function of illuminating the original and causing the quality of the read image and formed image to deteriorate. However, such an inconvenience can be solved by providing the eave-shaped reflecting plates 50a to 50e as in the present embodiment. The present invention can also be applied to a method of cooling a lamp of a general device using a curved tube lamp, for example, a video device using a strobe or the like.

[0009]

According to the first aspect of the present invention, since the lamp cooling air passage is located on the same radiation so as to face the lamp trigger band portion, the temperature rise of the trigger band portion is suppressed, so that the thermal shock is generated. This can prevent the deterioration of the bonding life due to this. In the document irradiating device according to the second aspect, since the lamp cooling air passage and the air outlet on the lamp light shielding plate have the same radial shape, hot air after cooling in the light shielding plate can be discharged, and the temperature of the lamp electrode and the trigger band can be suppressed. The life can be prevented from deteriorating. In the document irradiating device according to the third aspect, since the second eave-shaped light-shielding plate protrudes above the air outlet on the lamp light-shielding plate, light from the lamp does not directly reach the contact glass. Cooling becomes efficient, and the deterioration of image quality due to the light entering the document can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a document irradiation apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional plan view showing a configuration of a main part of FIG. 1;

FIG. 3 is a perspective view of a main part.

FIG. 4 is a sectional view of a band portion of a curved tube lamp.

FIG. 5 is a longitudinal sectional view showing a configuration of a document irradiation apparatus according to another embodiment of the present invention.

FIGS. 6 (a) and (b) are main part configuration diagrams of a conventional example and another embodiment of the present invention.

[Explanation of symbols]

1 curved tube lamp, 2 reflector, 3 contact glass,
4 manuscript, 5 reflection shade, 6 shading board, 7 scale 7,
8 upper base, 10 lower base, 11 lamp stand, 12 lamp holder, 13 inner cover, 1
4 duct, 15 blower section, 16 lamp cover, 17
Stay, 31a-31e groove (blowing path), 32 trigger electrode wire, 33a-33e band, 40a-40e
Opening (exhaust port), 50a-50e Reflector.

Claims (3)

[Claims] An arcuate curved lamp for illuminating a document placed on the contact glass is provided in the casing. The curved glass lamp has a contact glass on an upper surface of the casing. A plurality of air passages arranged radially for blowing cooling air from the center of curvature toward the curved tube lamp, and a curved tube for preventing direct light from the curved tube lamp from reaching the contact glass. And a light-shielding plate disposed above the lamp, wherein the trigger electrode band of the curved tube lamp is positioned on an extension of the outlet of each of the air passages. Document illumination device. 2. The document illuminating device according to claim 1, wherein an exhaust port is formed on the surface of the light shielding plate located on an extension of the outlet of the air passage. 3. The document illuminating device according to claim 2, wherein an eave-shaped light-shielding plate is provided protruding from an upper outer side of an air outlet of the light-shielding plate.