JPH01265656A - Optical system adjustment device for picture reader - Google Patents

Abstract

PURPOSE:To place a lens of an optical system to a prescribed location with high accuracy by supporting a guide shaft of a fixed unit via a plate spring and fixing the guide shaft and the plate spring by a screw penetrated through them. CONSTITUTION:The guide shaft 2 is supported by the fixed unit 4 by using a screw 13 penetrated via the plate spring 12. Through the constitution above, when the screw 13 is turned by some degree and the position where an elastic repulsing force of the plate spring 12 takes place is selected as the center of position adjustment, the vertical direction of the shaft 2, that is the optical block engaging with the shaft 2 is adjusted. Thus, the lens of the optical system is placed to a prescribed position with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical system adjustment device for an image reading device having a function of reading images such as texts and figures.

2. Description of the Related Art An example of an optical system of a conventional image reading apparatus will be described with reference to FIGS. 3 and 4.

FIG. 3 is a plan view showing the configuration of the main parts of the image reading device. In FIG. 3, 1 is a case, 2 is a guide shaft, and 3 is an optical book, which is engaged with the guide shaft 2 and is movable.

A fixed unit 4 is fixed to the case 1 or installed integrally with the case 1, and supports and fixes the guide shaft 2.

Figure 4 is a detailed sectional view of the fixed unit 4 seen from the axial direction of the guide shaft 2, and the guide shaft 2 is the fixed unit 4.
It is arranged at the corner of the L-shape and fixed by a leaf spring 5 and a screw 6.

Regarding the image reading device configured as above,
The operation will be explained below.

In FIG. 6, the document 8 that is in close contact with the transparent document table 7 is located at L
Illuminated by a light source 9 such as an ED array or a fluorescent light, the reflected light containing image information from the original 8 is reflected by a 1-magnification lens 10.
By condensing the light and further forming an image on the one-dimensional image sensor 11, image information of the original 8 in the main scanning direction is read.

That is, the light emitted from the light source 9 travels in the direction of the arrow in FIG. 6 and reaches the image sensor 11 containing image information. The optical block 3 including these members is driven by a suitable drive means (not shown) and is moved parallel to the document table 7 by the guide shaft 2, resulting in two-dimensional document reading.

Problems to be Solved by the Invention In conventional image reading devices, especially when miniaturization and compactness are required, it is necessary to adjust the relative distances of the optical systems such as the document table, lens, and image sensor mentioned above due to space considerations. There was no way to do so. Furthermore, although a 1-magnification lens is compact and can achieve a short focal length, its depth of focus is generally extremely short compared to a reduction lens. Due to the current practical accuracy of parts related to mounting lenses, sensors, etc., it has been difficult to respond to miniaturization and higher resolution.

Means for Solving the Problems In order to solve the above problems, the optical system adjustment device for an image reading device of the present invention has a movable mechanism in the fixed part of the guide shaft that supports the optical block. The distance between the document table and the document table can be adjusted.

Function The present invention makes it possible to realize a high-resolution apparatus while maintaining a small size by determining a predetermined position using the above-mentioned adjustment mechanism between the equal-magnification lens and the document table.

Embodiment Hereinafter, an optical system adjustment device for an image reading device according to an embodiment of the present invention will be described.

FIG. 1 is a front view and a side view of a main part of this embodiment.

Hereinafter, in these figures, parts corresponding to the conventional apparatus are given the same reference numerals.

In FIG. 1, a guide shaft 2 is supported and fixed to a fixing unit 4 by a screw 13 passing through a leaf spring 12.

In such a configuration, if the screw 13 is turned to a certain extent and the position where the elastic repulsive force of the leaf spring 12 is generated is the center of position adjustment of the guide shaft 2, the vertical adjustment of the guide shaft 2 can be adjusted accordingly. The matching optical block 3 (shown in FIGS. 3 and 4) can be adjusted. Here, the focus shift of the 1-magnification lens is mainly affected by the deviation of the center of the 1-magnification lens itself in the optical axis direction with respect to the center between the original and the image sensor, and other factors such as the distance between the original and the image sensor. Since the influence of misalignment of the document and image sensor is relatively small, the adjustment mechanism described above
All you have to do is align the center of the 1-magnification lens to the center between the two.

FIG. 2 shows another embodiment of the present invention, in which the guide shaft 2 is pressed against the fixing unit 4 by the leaf spring 6, and at the same time, the set screw 14 is engaged from the bottom of the case, and the guide shaft 2 is pressed against the fixing unit 4. By supporting the guide shaft 2 and turning the set screw 14, the guide shaft 2 can be adjusted in the vertical direction as in FIG.

Effects of the Invention According to the present invention, by adjusting the guide shaft fixing unit of the image reading device at four locations, the lens of the optical system can be placed in a predetermined position with high accuracy without enlarging the dimensions of the device itself. Furthermore, a device with high resolution can be obtained easily and at relatively low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an optical system adjustment device for an image reading device according to an embodiment of the present invention, FIG. 2 is a sectional view of a main part of another embodiment, and FIG. 3 is a plan view showing the configuration of a conventional example. FIG. 4 is a sectional view of the main part thereof, and FIG. 6 is a side view thereof. 2...Guide shaft, 4...Fixing unit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2--One side shaft (in (b))
4--Ichitatsumi =, 1 Kozuto Figure 2 (wa (0)

Claims (3)

[Claims] (1) A light source that irradiates a document placed in close contact with a transparent document table made of glass, a 1-magnification lens system that focuses reflected light from the document, and a plurality of light sources that read the focused reflected light. An optical image reading device comprising: a reading section configured with an image sensor having a photoelectric conversion element; a guide shaft member that causes the reading section to scan horizontally with the document table; and a fixing unit that supports the guide shaft member. System adjustment device. (2) The image reading device according to claim 1, wherein the fixing unit supports the guide shaft member via an elastic member and is fixed by a screw passing through the guide shaft member and the elastic member at the same time. Optical system adjustment device. (3) The fixing unit is configured so that a part of the guide shaft member is pressed diagonally upward by an elastic plate, and on the other hand, the part of the guide shaft member is supported by the tip of a screw that is engaged from the bottom of the fixing unit. The optical system adjustment device for an image reading device according to claim 1, characterized in that: