JPH0629264U - Light source device of image reading device - Google Patents

Abstract

(57) [Summary] [Purpose] Efficiently discharge the heat generated from the light source. [Structure] The reflection light source 8 is used in a scanner that irradiates a document with light and receives the light to read an image of the document. This device includes rod lenses 20a and 20b, halogen lamps 15a and 15b, heat insulating cases 19a and 19b, and blower fans 23 and 24. Rod lens 2
0a and 20b are arranged at positions that can face the document, and can emit light that has entered in the axial direction in the radial direction. The halogen lamps 15a and 15b are rod lenses 20a and 20b.
Is disposed on the base end side of and irradiates the rod lenses 20a and 20b with light. The heat insulating cases 19a and 19b surround the halogen lamps 15a and 15b. The blower fans 23 and 24 are
The air in the heat insulating cases 19a and 19b is discharged.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a light source device, and more particularly to a light source device of an image reading device that irradiates a document with light and receives the light to read an image of the document.

[0002]

[Prior art and its problems]

 For example, in a plane scanning type image reading apparatus such as a scanner, as shown in Japanese Utility Model Application Laid-Open No. 3-5490, a light source section including a light source and a rod lens, and a CCD for receiving light obtained from the light source section through a document. A light receiving element including a line sensor and an optical system including a lens and a reflection mirror for guiding light to the light receiving element are provided. In this type of image reading device, image data is read in the main scanning direction by irradiating a document with linear light and performing slit exposure.

The rod lens is arranged at a position where it can face the original document, and can emit light incident in the axial direction in the radial direction. In addition, the light source is arranged on the base end side of the rod lens. In the above conventional configuration, the heat generated by the halogen lamp remains inside the device, and the temperature inside the device rises. There is also known a configuration in which a blower fan is arranged near the halogen lamp, but the air flow around the halogen lamp is poor and the generated heat cannot be efficiently discharged to the outside of the device.

An object of the present invention is to efficiently dissipate heat generated from a light source.

[0005]

[Means for Solving the Problems]

 The light source device according to the present invention is a device used for an image reading device that irradiates a document with light and receives the light to read the image of the document. This device includes a rod lens, a light source, a heat insulating case, and an exhaust means. The rod lens is arranged at a position where it can face the document and is capable of emitting light incident in the axial direction in the radial direction. The light source is arranged on the base end side of the rod lens and irradiates the rod lens with light. The heat insulating case surrounds the light source. The exhaust means is for exhausting the air in the heat insulating case to the outside of the device.

[0006]

[Action]

 In the light source device according to the present invention, when the light source is turned on, the light is incident in the axial direction of the rod lens and is irradiated on the document from the radial direction of the rod lens. Here, the light source is surrounded by the heat insulating case, and the air in the heat insulating case is exhausted by the exhaust means. Therefore, the heat generated from the light source can be efficiently discharged together with the air.

[0007]

【Example】

 FIG. 1 shows an image reading apparatus (hereinafter referred to as a scanner) 1 adopting an embodiment of the present invention. The scanner 1 includes a lower frame 2 and an upper frame 3 placed on the lower frame 2. A document placing device 4 is arranged on the upper surface of the lower frame 2. Further, as shown in FIG. 2, at the center of the lower frame 2, below the document placing device 4, a transmission light source 7 for slit exposure of a transmission document is vertically movable.

The document placing device 4 has a document table 5 movable in the sub-scanning direction shown by an arrow in FIG. 2 and a drive mechanism 13 for driving the document table 5. The document table 5 is capable of placing a document 6 up to 483 mm × 646 mm (A4 4 sheets + registration marks), and is configured to sandwich the document 6 between a pair of upper and lower glass plates. The upper frame 3 is provided with a reflection light source 8 for slit exposure of a reflection original, an optical system 9, and a light receiving element 10 composed of four CCD line sensors arranged in parallel in the main scanning direction. There is. The optical system 9 includes a reflection mirror 11 that bends the light from the document 6 in the horizontal direction by 90 degrees, and four lenses 12 for forming an image of the light from the reflection mirror 11 on the light receiving element 10. ing. The lens 12 is arranged in the image reading line on the document table 5 so that the ends of the fields of view overlap.

The reflection light source 8 has two halogen lamps 15a and 15b, as shown in FIGS. As shown in FIG. 4, the halogen lamps 15a and 15b are arranged so as to be slightly deviated to the opposite sides in the sub-scanning direction with respect to the exposure center line E in the original document. The halogen lamps 15a and 15b are arranged so as to face each other on both sides of the exposure center line E.

Concave mirrors 16a and 16b are arranged on the back side of the halogen lamps 15a and 15b. The concave mirrors 16a and 16b are for concentrating the light emitted from the halogen lamps 15a and 15b on the rod lens side. On the opposite side of the halogen lamps 15a and 15b from the concave mirrors 16a and 16b, the base ends of rod lenses 20a and 20b which are long in the main scanning direction are arranged. The two rod lenses 20a and 20b are arranged in parallel. A linear irregular reflection layer (not shown) is formed on each of the rod lenses 20a and 20b, and the rod lenses 20a and 20b can emit light incident from the base end in the radial direction. Thus, by arranging the pair of halogen lamps 15a and 15b and the rod lenses 20a and 20b so as to face each other, it is possible to prevent the generation of shadows on the document 6 and to make the distribution of the irradiation light amount on the document 6 substantially uniform. You can

Red line cut filters 17a and 17b are arranged between the rod lenses 20a and 20b and the halogen lamps 16a and 16b. As a result, the heat generated from the halogen lamps 17a and 17b is absorbed, and the light excluding the infrared rays reaches the rod lenses 20a and 20b. The halogen lamps 15a and 15b, the concave mirrors 16a and 16b, and the infrared cut filters 17a and 17b are surrounded by box-shaped heat insulating cases 19a and 19b, respectively. Holes 18a and 18b for inserting the base ends of the rod lenses 20a and 20b are formed in the heat insulating cases 19a and 19b. The diameter of this hole is slightly larger than the diameter of the rod lenses 20a, 20b, and a slight annular gap is formed on the outer peripheral side of the rod lenses 20a, 20b.

One ends of the heat insulating cases 19a and 19b are connected to a duct 22 which is long in the main scanning direction. The heat insulating cases 19a and 19b and the duct 22 are communicated with each other through communication holes 21a and 21b. One end of the duct 22 on the heat insulating case 19b side is opened outward from the upper frame 3. A blower fan 24 is arranged in this open portion. Further, a blower fan 23 is arranged in the duct 22 in the vicinity of the communication hole 21b. That is, the blower fans 23 and 24 are arranged in series in the duct 22.

Next, the operation of the above embodiment will be described. When the document 6 is mounted on the document table 5 and the operator inputs a scanning start command, the transmissive light source 7 or the reflective light source 8 is turned on. Then, the document table 5 is moved in the sub scanning direction by the drive mechanism 13. The light emitted from the light source 7 or the light source 8 passes through the document 6 and is received by the light receiving element 10 via the reflection mirror 11 and the lens 12. As a result, the original 6 is read and an electric signal corresponding to the image is obtained.

In the above-described reading operation, when the original 6 is a reflective original, the reflection light source 8 is used. In the reflection light source 8, when the halogen lamps 15a and 15b are turned on, the air in the heat insulating cases 19a and 19b is heated by the heat generated from the halogen lamps 15a and 15b. On the other hand, when the halogen lamps 15a and 15b are turned on, the blower fans 23 and 24 start operating. As a result, it is possible to prevent the air in the heat insulating cases 19a and 19b from being sucked by the blower fans 23 and 24 and discharged to the outside of the apparatus, and from being diffused into the apparatus from the heat insulating cases 19a and 19b. Further, air flows into the heat insulating cases 19a and 19b from the insertion holes 18a and 18b, and the air that has flowed in can cool the air inside the heat insulating cases 19a and 19b.

At this time, since the blower fan 23 and the blower fan 24 are arranged in series, a strong suction force is obtained with respect to the heat insulating case 19b, and the cooling effect is enhanced. Further, since the communication hole 21a of the heat insulating case 19a is opened to the side wall of the duct 22, the negative pressure effect generated by the air flowing through the duct 22 enhances the cooling effect in the heat insulating case 19a.

[Other Embodiments] (a) The number of light sources is not limited to two and may be one. Further, instead of the halogen lamp, another light source such as a metal halide lamp may be used. (B) Instead of sucking the air in the heat insulating case, the air in the heat insulating case may be pushed out.

[0017]

[Effect of device]

 In the light source device according to the present invention, the air in the heat insulating case surrounding the light source is exhausted by the exhaust means, so that the heat generated from the light source can be efficiently exhausted to the outside.

[Brief description of drawings]

FIG. 1 is a perspective view of a scanner adopting an embodiment of the present invention.

FIG. 2 is a schematic sectional view thereof.

FIG. 3 is a perspective view of a light source for reflection.

FIG. 4 is a schematic cross-sectional view of a light source for reflection.

[Explanation of symbols]

 1 Scanner 6 Original 8 Reflection Light Source 15a, 15b Halogen Lamp 19a, 19b Insulation Case 20a, 20b Rod Lens 22 Duct 23, 24 Blower Fan

Claims (1)

[Scope of utility model registration request] 1. A light source device of an image reading device for irradiating a document with light and receiving the light to read an image of the document, the light being arranged in a position facing the document and being incident in the axial direction. A rod lens that can be emitted in a radial direction, a light source that is disposed on the base end side of the rod lens and irradiates the rod lens with light, a heat insulating case that surrounds the light source, and air in the heat insulating case that is external to the device. A light source device for an image reading device, comprising: