JPS6135062A - Optical picture reader - Google Patents

Abstract

PURPOSE:To attain sure reading of an original by providing an image forming lens system and a photoelectric converting element to a case and providing a moving body having movably a light source to the case to attain ease of adjustment of the conjugate length of the image forming system lens. CONSTITUTION:An SELFOC lens array 6 being an image forming lens system is penetrated to the case 20 of an optical picture reader and a photoelectric converting element 8 is provided to the upper face of the case 20. Further, a mobile body 22 is provided with a projected shape light source supporting part 24 and a paper retainer 26 and the support 24 is provided with an LED array 2 being a light source. The case 20 and the mobile body 22 are screwed by a screw adjusting screw 28 and a plate spring 30 is provided to a separated part. Then the position adjustment of the light source attended with the adjustment of the conjugate length of the image forming lens system becomes unnecessary, the working performance is improved and thermal effect by the light source to the photo electric converting element 8 is decreased to ensure the reading of the original 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical image reading device, and more particularly to an optical image reading device that can easily and reliably adjust the position of an original, an imaging lens system, and a light source.

[Prior art]

Generally, optical image reading devices such as facsimile machines, copying machines, and image sensors have a configuration as shown in FIG.

That is, light is irradiated onto the original 4 from the LED array 2 which is a light source, and the light reflected by the original 4 is transmitted to a focusing light transmitting body such as a selfoc lens array (product name: Nippon Sheet Glass Co., Ltd., hereinafter referred to as SLA) which is an imaging lens system. The light is focused onto a photoelectric conversion element 8 by a photoelectric conversion element 8, and the information on the document 4 is read. Manuscript 4
The reading is performed while being moved in the direction shown in the figure by the rotation of the roller 10.

FIG. 0 is a side view of the SLA, and in general, it is ideal to adjust the conjugate length 12 and the conjugate length x 1714 to position the SLA in the focal direction. However, in conventional image reading apparatuses, only the conjugate length x W 14 is adjusted or no adjustment is made. Note that 16 is the optical center of SLA 6.

Recently, as the demand for this type of image reading apparatus has increased, the demand for high resolution, high speed operation, etc. has increased, and in response to this, it has become necessary to further refine the adjustment of the imaging lens system. However, the conventional 8LA positioning method cannot meet this requirement, so an optical image reading device capable of adjusting the conjugate length has been devised.

FIG. 0 shows a cross-sectional view of this optical image reading device.A large number of paper pressers 1B with different thicknesses are prepared.
The conjugate length 12 of the p SLA 6 is adjusted by removably providing each paper presser 18 at the bottom of the casing 20.

However, this image reading device has the following drawbacks.

(1) If the conjugate length is adjusted as shown in FIG. 5, there will be a shift between the illumination position of the LED array 2 and the reading position, making it impossible to perform reliable reading.

(2) Fine adjustment of the conjugate length requires many types of paper pressers 18 having different thicknesses, which increases the number of parts.

(3) When adjusting the conjugate length, it is necessary to remove and replace the paper presser 18, which results in poor work efficiency.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical image reading device that can read documents reliably, has good workability, and is low in cost in order to eliminate the above-mentioned drawbacks.

〔composition〕

In order to achieve the above object, the present invention is characterized in that an imaging system and a photoelectric conversion element are provided in a housing, and a movable body having a light source is movably provided in the housing.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a cross-sectional view of an optical image reading device according to an embodiment of the present invention. As shown in the figure, an SLA 6 as an imaging lens system is installed through a housing 20, and the upper surface of the housing 20 is A photoelectric conversion element 8 is provided. Reference numeral 22 indicates a moving body, and the moving body 22
has a protruding light source support portion 24 and a paper presser portion 26, and the light source support portion 24 is provided with an LBD array 2 serving as a light source. The housing 20 and the movable body 22 are screwed together by an adjustment screw 28, and a leaf spring 30 is provided at a portion where the housing 20 and the movable body 22 are separated from each other.

Next, the operation of this embodiment will be explained. Movable body 220 paper holding part 26Fi is always in contact with document 4 9, adjustment screw 2
By adjusting 8, the movable body 22 is moved in the direction of the distance between the housing 20 and the document 4, that is, in the direction of {circle around (2)} in the figure.

When the moving body 22 moves in the ■ direction, the conjugate length of the SLA 6 changes, but since the LED array 2Fi moves together with the moving body 22, the positional relationship between the document 4 and the LED array 2 does not change, and the illumination due to the adjustment of the conjugate length changes. No positional deviation occurs. Furthermore, adjustment using the adjustment screw 28 can be performed from the photoelectric conversion element side, and can be performed within the actual built-in equipment, making the adjustment more effective.

〔effect〕

As described above in detail and specifically, the present invention provides the following significant effects.

1) The conjugate length of the imaging lens system can be easily adjusted and documents can be read reliably.

2) There is no need to adjust the position of the light source in conjunction with adjustment of the conjugate length of the imaging lens system, resulting in improved workability.

3) The thermal influence of the light source on the photoelectric conversion element is reduced.

4) Unlike the conventional paper presser, the number of unnecessary parts can be reduced and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an optical image reading device according to an embodiment of the present invention, FIG. 2 is a perspective view of the optical image reading device, and FIG. 3 is an explanatory diagram showing the conjugate length of a SELFOC lens array. FIG. 4 is a sectional view of a conventional optical image reading device, and FIG. 5 is an enlarged view of the main part of FIG. In the figure, 2: LED array, 4: Original, 6: SELFOC lens array, 8: Photoelectric conversion element, 20: Housing, 22: Moving body, 28: Adjustment screw , 30...
・It is a leaf spring.

Claims (1)

[Claims] (1) In an optical image reading device in which a document is irradiated with light emitted from a light source and the light passing through the document is imaged on a photoelectric conversion element by an imaging lens system; What is claimed is: 1. An optical image reading device, comprising a photoelectric conversion element, a movable body movable in the direction of the distance between the casing and the document, and having the light source movably provided in the casing.