JP2002359729A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader which can be downsized and obtain excellent quality by contriving the selection and arrangement or the like of components, particularly light sources. SOLUTION: In the image reader having light sources 1 emitting light to an original 3, a field lens 4 acting like an image forming means that forms an image from the light emitted from the light source and reflected light in the original 3, and a photoelectric conversion means 6 that converts the formed reflected light image into an image signal, the light sources are characterized in that LEDs are placed along a plane perpendicular to the face of the original 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image reading device such as an image scanner.

[0002]

2. Description of the Related Art Conventionally, a light source for irradiating a document with light is generally provided so as to face the document along the document irradiation direction.

As an example in which a light source is installed so as to face a document along a document irradiation direction, a configuration disclosed in Japanese Patent Application Laid-Open No. 9-51402 is known.

[0004]

However, when a light source for irradiating light on a document is installed to face the document along the document irradiation direction as in the above-described conventional example, the distance from the reading optical axis is reduced. Cannot be reduced due to the size of the light emitting source, which may be disadvantageous for downsizing the device.

The present invention has been made in view of the above points, and provides a high quality image reading apparatus while achieving downsizing by devising the selection and arrangement of components, especially light sources. The purpose is to:

[0006]

The present invention can solve the above-mentioned problems by providing the following constitution.

(1) A light source for irradiating the original with light, an image forming means for forming an image of reflected light emitted from the light source and reflected by the original, and converting the formed reflected light into an image signal An image reading apparatus, comprising: a photoelectric conversion unit that performs lighting; wherein the light source includes an LED disposed along a plane perpendicular to a document surface of the document.

(2) The image forming means and the photoelectric conversion means share the axis of the optical axis of the reflected light perpendicular to the original surface of the original, and lie on two planes orthogonal and parallel to the optical axis. The image reading device according to the above (1), wherein the image reading devices are arranged respectively.

(3) The image reading apparatus according to the above (1) or (2), wherein the light source is a bare chip LED and is arranged in parallel with a pixel array of the photoelectric conversion means.

(4) The light source is mounted on the same circuit board as the photoelectric conversion means.
The image reading device according to any one of (3).

(5) The image as described in any one of (1), (3) and (4) above, wherein an irradiation angle of the original by the light source is 45 ° or more and 80 ° or less from the original surface. Reader.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the image reading apparatus according to the present invention will be described below.

FIG. 1 is an explanatory cross-sectional view showing a main part of an image reading apparatus according to an embodiment of the present invention. FIG. 2 is an explanatory view showing a configuration of a light source of the image reading apparatus according to an embodiment of the present invention. FIG. 3 is an explanatory cross-sectional view showing a configuration of a main part of an image reading apparatus in a conventional example.

A description will be given below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a light source for irradiating a document with light, which comprises a plurality of LEDs and a fluorescent LED using an LED as an excitation source, and is arranged along a plane perpendicular to the document surface.

The light source 1 composed of a plurality of LEDs or the like has a spectral characteristic suitable for color reading at different wavelengths when used in a color image reading apparatus.

When the light source 1 is turned on, the light from the light source 1 illuminates the original 3 with an illumination angle θ of 45 ° or more and 80 ° or less from the original surface via an illumination lens 2 as a light collecting means.

The reflected light from the document 3 passes through a field lens 4 as an image forming means and an image forming lens 5 which are arranged with an optical axis in a direction perpendicular to the document surface and an image of a CMOS or the like as a photoelectric conversion means. An image is formed on the sensor 6 and converted into an image signal.

Reference numeral 7 denotes a case. Reference numeral 8 denotes a holder (frame). The case 7 includes an imaging lens 5, an image sensor 6 as a photoelectric conversion unit, and a printed circuit board 9 as a circuit board on which the light source 1 is mounted. A predetermined positional relationship is held through the holder 8.

FIG. 2 is an explanatory diagram showing the configuration of the light source of the image reading apparatus according to the embodiment of the present invention.

In FIG. 2, the light source 1 is constituted by arranging three LEDs on the same substrate circuit in a row in the reading width direction.

The first light source 1r located at the center is a fluorescent LED for emitting red light, and the second light source 1b is an LED for emitting blue light. 1g is an LED that emits green light, and is disposed outside the other side of the first light source.

The above-mentioned LEDs are constituted by bare-chip LEDs.

FIG. 3 is an explanatory cross-sectional view showing the configuration of a main part of an image reading apparatus in a conventional example. As is apparent from comparison with FIG. This shows a state where the image reading apparatus is extremely miniaturized.

[0025]

As described above, according to the present invention, the size and size of the image reading apparatus can be reduced and the quality of the image reading apparatus can be improved by improving the selection and arrangement of the components, especially the light sources. Can be achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view illustrating a main configuration of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a light source of the image reading apparatus according to the embodiment of the present invention.

FIG. 3 is an explanatory cross-sectional view showing a configuration of a main part of an image reading apparatus in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source 1r Red fluorescent LED 1g Green LED 1b Blue LED 2 Illumination lens 3 Original 4 Field lens 5 Imaging lens 6 Image sensor (photoelectric conversion means) 7 Case 8 Holder (frame) 9 Printed circuit board θ Light source irradiation angle (Reference numerals used in conventional examples) 11 light source 12 illumination lens 13 document 14 field lens 15 imaging lens 16 image sensor 17 case 18 holder (frame) 19 printed circuit board

Claims (5)

[Claims] 1. A light source for irradiating a document with light, an image forming means for forming an image of reflected light emitted from the light source and reflected by the document, and converting the formed reflected light into an image signal An image reading device comprising: a photoelectric conversion unit, wherein the light source emits light along a plane perpendicular to a document surface of the document.
An image reading apparatus, wherein D is installed. 2. The image forming means and the photoelectric conversion means share an axis of an optical axis of reflected light perpendicular to the document surface of the document, and are respectively provided on two planes orthogonal and parallel to the optical axis. The image reading device according to claim 1, wherein the image reading device is arranged. 3. The image reading apparatus according to claim 1, wherein the light source is a bare chip LED, and the light source is arranged in parallel with a read pixel array of the photoelectric conversion unit. 4. The image reading apparatus according to claim 1, wherein said light source is mounted on a same circuit board as a photoelectric conversion unit. 5. An image reading apparatus according to claim 1, wherein an irradiation angle of the original by the light source is not less than 45 ° and not more than 80 ° from an original surface.