JPH07212532A - Image input device - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent generation of dark current due to heat in the CCD provided in the image input device and to obtain an image of good quality without requiring special elements or circuits. . [Structure] Illumination section 31 and document scanning section 3 are provided in case 15.
2. The image forming units 33 are arranged in three layers in the vertical direction,
The air intake hole 20 is formed in the case 15 near the CCD 14, and the exhaust fan 2 is installed in the case 15 at a position facing the light source 8.
1 is provided to efficiently cool each part in the case 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input device in which a reflective original or a transparent original is irradiated with light from a light source as a light emitting means and an image on the original is read by a CCD as a photoelectric conversion means.

[0002]

2. Description of the Related Art The construction of a conventional example of this type of image input apparatus is shown in FIGS. In these figures, a film 1 as a transparent original is held by a mount portion 2a of a slide 2, a slide 2 is detachably held by a holder 4 provided on a stage 3, and the stage 3 is driven by a driving mechanism 5a. Driven by. The drive mechanism 5 includes a lead screw 6 that is screwed onto the stage 3 and a stage motor 7 that rotationally drives the lead screw 6.

The film 1 is a light source 8 such as a halogen lamp.
To diffuser plate 9, color filter 10, condenser lens 11
It is irradiated by the light flux emitted via the. Film 1
The optical axis of the transmitted light that has passed through is bent at a right angle by the mirror 12, and is imaged by the lens 13 on the CCD 14 which is a line-type image sensor. In this way, the image of the film 1 is read by the CCD 14, photoelectrically converted, and the image signal is input to an image processing unit (not shown). In addition,
The color filter 10 is provided with filters of three colors of red, green, and blue, and a color image is input by alternately irradiating the same image.

A case 15 as a storage means is provided with a concave portion 16 forming a moving space of the stage 3 and convex portions 17 and 18 arranged on both sides of the concave portion 16, respectively. On one convex portion 17, a light source 8, a diffusing plate 9, a color filter 10, a condenser lens 11, etc., and a power source 19 are provided.
Are accommodated in the other convex portion 18, and the image forming portions such as the mirror 12, the lens 13 and the CCD 14, and the driving mechanism 5 of the stage 3 are accommodated in the other convex portion 18.

On the side surface of the convex portion 17, the condenser lens 1
An air intake hole 20 as an air intake means is provided at the position 1 and an exhaust fan 21 as an air discharge means is provided at the position of the light source 8 at the rear of the convex portion 17. Then, the heat generated from the light source 8 and the power source 19 is discharged to the outside of the case 15 by the exhaust fan 21.

[0006]

In the image input apparatus constructed as described above, a light source 8 such as a halogen lamp which generates heat is used as a light source, and a power source 19 for driving an electric circuit is used. Heat is also generated from. On the other hand, the characteristics of the CCD 14 as a light receiving element are easily affected by the ambient temperature. Therefore, it is necessary to suppress the temperature rise of the CCD 14 and reduce the influence of dark current to improve the image quality. That is, in order to prevent heat generated from the light source 8 or the power source 19 from reaching the CCD 14, conventionally, the light source section and the image forming section are arranged on both sides of the concave section 16 that constitutes the moving space of the stage 3, and the convex sections are respectively formed. It was housed in parts 17, 18. However, even with the above configuration, the flow of air is insufficient, and the heat generated from the light source 8 and the power source 19 reaches the periphery of the CCD 14 and the dark current increases, resulting in the problem of deterioration of image quality.

As a means for reducing the dark current, there is a method of using a Peltier element, but there is a drawback that a drive circuit for driving the Peltier element is required and the apparatus becomes complicated and expensive.

The present invention has been made in view of the above circumstances, and provides an image input device which does not require a special element or circuit and which can suppress the generation of dark current to obtain an image of good quality. The purpose is to do.

[0009]

To achieve the above object, the present invention according to claim 1 provides a light source 8 as a light emitting means for illuminating an image of a film 1 as an original, and a light from the film 1. CCD 14 as photoelectric conversion means for reading the image by means of the above, and stage drive mechanism 5 as document feeding means for placing the film 1 and moving in the sub-scanning direction.
In the image input device including the light source 8, the CCD 14, and the case 15 as a storage means for storing the stage drive mechanism 5, an air intake hole as an air suction means is provided in the case 15 close to the CCD 14 and the light source 8, respectively. 20 and an exhaust fan 21 as an air discharging means are provided.

An image input device according to a second aspect of the present invention is a light source 8
And the CCD 14 are arranged on one side of the case 15 and on the opposite side of the bottom, respectively, and the stage drive mechanism 5 is arranged in the middle part of the case 15 in the height direction.

The image input device according to the third aspect is characterized in that the air discharging means has an exhaust fan 21.

[0012]

In the image input device having the above construction, the outside air is sucked in through the air intake hole 20 formed in the lower part of the case 15 and in the vicinity of the CCD 14, and the power source 19, the stage motor 7, the light source 8 in the case 15 and the like. After absorbing the heat generated from the fan 15, it is discharged to the outside by a fan motor 21 provided near the light source 8 above the case 15. As a result, the heat can be efficiently discharged to the outside due to the flow from the intake of the air to the discharge, and the compensation of the dark current of the CCD 14 is not required, and an image of good quality can be obtained. Also,
Since the mechanical operation of the device and the arrangement configuration of the respective parts are reasonable, the device can be downsized.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the image input device of the present invention will be described below with reference to the drawings.

1 and 2 show the structure of an embodiment of the present invention. In these figures, portions corresponding to those of the conventional example shown in FIGS. 3 to 5 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In FIGS. 1 and 2, the case 15 is formed in a cubic box shape, and an opening 15a for inserting and removing the holder 4 is provided on one front surface of the case 15. The inside of the case 15 is composed of almost three layers, and an illumination unit 31, a document scanning unit 32, and an image forming unit 33 are arranged in this order from the top.

The illuminating unit 31 includes a light source 8 such as a halogen lamp arranged on the right side of the drawing, a diffusion plate 9, a color filter 10,
The first condenser lens 11a, the first mirror 34, the second mirror 35, the third mirror 36, and the second condenser lens 11b are included. The light emitted from the light source 8 is emitted from the first, second and third mirrors 34, 35 and 3
The optical paths are bent at right angles by 6 to irradiate the surface of the film 1 at right angles. Therefore, since the optical path is folded and arranged parallel to the surface of the film 1, the illumination unit 3
1 can be thinned.

The original scanning unit 32 is a holder 4 for the film 1.
The stage 3 and the lead screw 6 and the stage motor 7 are used as a drive mechanism 5 and the like. The lead screw 6 and the stage 3 are arranged parallel to the optical path of the illumination unit 31.

The image forming unit 33 is composed of a mirror 12, a lens 13 and a CCD 14, and the optical path reflected by the mirror 12 is arranged parallel to the optical path of the illuminating unit 31.
The line 1 CCD 1 is used to read the image on the film 1.
4, the illumination area on the film 1 is CC
A linear shape corresponding to D14 may be used, and Fresnel-type condenser lenses 11a and 11b and a mirror 3 that constitute the illumination unit 31.
Since the lines 4, 35, and 36 may also be linear, the optical path of the illumination optical system can be folded and arranged as described above, and the thin illumination unit 31 can be configured.

Further, at the lower left side of the case 15 in the drawing, C
An air intake hole 20 is formed at a position facing the CD 14, and an exhaust fan 21 is provided on the upper right side of the case 15 in the drawing.
Is provided.

Next, the operation of this embodiment will be described. After setting the film 1 in the holder 4, the film 1 is inserted into the stage 3 moved to the left side through the opening 15a and fixed on the stage 3. The stage 3 is driven by the drive mechanism 5 to move to the right side, and sub-scanning for reading the image of the film 1 is performed.

On the other hand, the light source 8 is turned on, and the reading position of the film 1 is illuminated by the illumination unit 31. Film 1
The light transmitted through the above image is focused on the CCD 14 via the mirror 12 and the lens 13, and the image of one line is read. By repeating this reading operation in the main scanning direction while sequentially moving in the sub scanning direction, that is, the moving direction of the film 1, the image of the film 1 can be two-dimensionally input.

The color filter 10 has three colors of red, green and blue.
A color image can be input by providing a color filter and alternately reading the same image.

During operation of the above image input apparatus, the power source 1 for driving the stage motor 7, turning on the light source 8, and driving the circuit.
Heat is generated by 9 or the like. However, outside air is sucked in from an air intake hole 20 formed near the CCD 14 below the case 15, and the stage motor 7 in the case 15
After absorbing the heat generated from the light source 8, the power source 19, etc., the heat is exhausted to the outside by the exhaust fan 21.
It is possible to prevent the ambient temperature of 4 from rising.

According to the present embodiment, the flow from the intake of the outside air to the discharge of the outside air can be formed without difficulty in the order of the vicinity of the CCD 14, the periphery of the document reading portion, the power source 19 and the light source 8, so that a special Peltier element or the like is used. An element and a circuit for driving this element are unnecessary, and it is possible to suppress an increase in dark current generated in the CCD 14 and input a good image. Further, since the mechanical operation of the device and the arrangement configuration of each part are not unreasonable, the device can be downsized.

In the above-mentioned embodiment, the original is the film 1 as the transparent original, but the same effect can be obtained by applying it to the image input device for reading the reflective original.

[0026]

As described above, according to the image input apparatus of the present invention, the air intake means and the air discharge means are provided in the storage means surrounding the outer periphery of the apparatus in the vicinity of the photoelectric conversion means and the light emission means, respectively. Therefore, the flow of the outside air in the storage means can be efficiently formed, and the heat generated from each part can be sufficiently discharged to the outside. Therefore, it is possible to input an image of good quality by suppressing an increase in dark current generated in the photoelectric conversion means without requiring a special element or circuit.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an internal schematic configuration of an embodiment of an image input apparatus of the present invention.

FIG. 2 is an external perspective view of FIG.

FIG. 3 is a cross-sectional view showing an internal schematic configuration of an example of a conventional image input device.

FIG. 4 is a vertical sectional view of FIG.

5 is an external perspective view of FIG.

[Explanation of symbols]

 1 film (original) 5 stage drive mechanism (original feeding means) 8 light source (light emitting means) 14 CCD (photoelectric conversion means) 15 case (storage means) 20 air intake hole (air suction means) 21 exhaust fan (air discharge means) )

Claims (3)

[Claims] 1. A light emitting unit for illuminating an image of a document, a photoelectric conversion unit for reading the image by light from the document, a document feeding unit for placing the document and moving in the sub-scanning direction, and the light emission. An image input device comprising: a storage unit, a storage unit for storing a photoelectric conversion unit and a document feeding unit; and an air intake unit and an air discharge unit provided in the storage unit in proximity to the photoelectric conversion unit and the light emitting unit, respectively. An image input device characterized in that 2. The light emitting means and the photoelectric conversion means are arranged on one upper side and the opposite lower side of the accommodating means, respectively, and the document feeding means is arranged at an intermediate portion in the height direction of the accommodating means. The image input device according to claim 1. 3. The image input device according to claim 1, wherein the air discharging unit has an exhaust fan.