JPS6022545B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In a facsimile machine or the like, the present invention allows reflected light from a document surface to enter a reading element such as an image sensor, and causes the reading element to perform photoelectric conversion. The present invention relates to an image discussion device that reads images of characters, figures, etc.

Conventionally, image reading devices in facsimile machines have had various configurations, but in general, the image reading device with the configuration shown in Figure 1 is widely used as it is simple and performs its functions reliably. It is used.

First, to explain this conventional device, a frame 2 and an optical bench 3 are fixed to a substrate 1.

A paper feed roller 4 is rotatably supported on the frame 2 and a crab light 5 is attached thereto, and a lens 6 and an image sensor 7 are fixed to the optical bench 3.
In this conventional apparatus, the document 8 is fed in the sub-scanning direction by the rotation of the paper feed roller 4 and is illuminated by the honeycomb lamp 5 .

The light reflected from the surface of the document 8 caused by this illumination is focused by the lens 6 and incident on the light receiving surface of each pixel of the image sensor 7, whereby the bridge document 8 is read and scanned. At this time, the intersection of the straight line 9 connecting the light receiving surface of each pixel of the image sensor 7 with the center of the lens 6 and the surface of the original 8 becomes a scanning point 10 for reading. In order to read the document 8 with high precision, it is necessary that the scanning point 10 be at the correct position and that the image of the scanning point 10 be clearly formed on the light receiving surface. is the elevation angle 8 of the straight line 9 and the distance L between the light receiving surface and the scanning point 10
must always be held at the correct value.

In particular, when the distance L becomes narrow, the image formed on the light-receiving surface of the image sensor 7 becomes blurred, and the captured image deteriorates rapidly. Furthermore, a narrow elevation angle a leads to fluctuations in the distance L, which also results in poor imaging conditions. Therefore, in this conventional device,
After adjusting the elevation angle 8 and the distance L, the substrate 1 must have sufficient rigidity so that the positional relationship between the frame 2 and the optical bench 3 will not be distorted and the elevation angle 8 and the distance L will not be distorted. In other words, the structure of the entire facsimile apparatus must be made extremely rigid, which increases the weight and manufacturing cost of the entire facsimile apparatus. However, in recent years, there has been a strong social demand for facsimile machines to be cheaper and lighter, and the increase in weight and manufacturing cost due to the conventional configuration has been a major obstacle to realizing this demand. Further, in the conventional device, the lens 6 and the image sensor 7
The position adjustment of the optical bench 3 must be performed within the facsimile machine after the optical bench 3 is fixed to the substrate 1, which has the disadvantage that the adjustment is not easy and requires a long time.
The present invention has been made to solve the above-mentioned conventional drawbacks, and can prevent distortion from occurring in the optical path without increasing the weight and manufacturing cost, and the time required for adjusting the optical system. An object of the present invention is to provide an image reading device that can significantly shorten the time required.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 2 shows a side view of the main parts, and FIG. 3 shows a plan view thereof. A frame 2 is attached to the device exterior 11, and a paper feed roller 4 is rotatably supported on this frame 2. , a crab light lamp 5 is attached. The paper feed roller 4 is driven by a drive device (not shown) to feed the document 8 in the sub-scanning direction. Further, in the frame 2,
A pair of support shafts 12 are supported on both sides of the paper feed roller 4.

The axes of these support shafts 12 coincide with an imaginary straight line 13 of the book, which passes in the main scanning direction over the front surface of the document 8 at the portion where the paper feed roller 4 is located on the back surface thereof.
One end of a plate-shaped arm 14 is rotatably supported on each of the support shafts 12, so that each arm 14 is rotatable about the straight line 13. Each arm 1
An optical bench 3 is fixed to the end of the tube 4, and a lens 6 and an image sensor 7 are fixed to the optical bench 3.

A receiving plate 15 is fixed to the lower surface of the optical bench 3, and this receiving plate 15 is provided with screw insertion holes (not shown). A screw 16 is inserted into the screw insertion hole from above to below with an appropriate margin, and the tip side of this screw 16 is
It is screwed onto the device exterior 11.

A spring IT is interposed between the receiving plate 15 and the device exterior 11, and this spring 17 pushes the receiving plate 15 upward.
It is biased in the direction that the bale hits the back of the head. In this image reading device, the scanning point 10 is located on the virtual straight line 13, and the lens relative to the optical bench 3 is arranged such that the image of the scanning point 10 in parentheses is clearly formed on the light receiving surface of each pixel of the image sensor 7. Once the positions of the image sensor 6 and the image sensor 7 are adjusted, the arm length (distance L) remains unchanged and the arm 14 can freely rotate around the straight line 13. As long as the arm 14 and the optical bench 3 are not deformed even if they are moved, the adjusted state is always maintained thereafter.

In this embodiment, even if the device exterior 11 is deformed,
By displacing the receiving plate 15 with respect to the screw 16 against the spring 17, the arm 14 is only slightly rotated, but the arm 14 and the optical bench 3 are not deformed.

Therefore, while the distance L remains unchanged, the scanning point 10 is always located on the virtual straight line 13, and the scanning point 1 in parentheses
The image of 0 is always clearly formed on the light receiving surface. Therefore, there is no need to increase the rigidity of the device exterior 11 so much. Furthermore, in this device, since the distance L between the scanning point 10 and the image sensor 7 is determined by the length of the arm 14, the optical bench 3 attached to the arm 14 is set on an appropriate jig. Since the positions of the lens 6 and the line image sensor 7 can be adjusted outside the device and then incorporated into each device, the optical adjustment becomes extremely easy and the time required for the adjustment work can be significantly shortened.

FIGS. 4 and 5 are a side view and a plan view showing another embodiment.

The arm 14' has a circular or square cross section, and is rotatably supported directly on the frame 2 by having its one end braced with an arm support hole 18 provided in the frame 2. There is. A straight line connecting these two arm support holes 18 coincides with the virtual straight line 13. Further, an elastic material 19 such as a piece of sponge is interposed between the receiving plate 15 and the device exterior 11 in place of the spring 17 in the previous embodiment, and this elastic material 19 is arranged so that the receiving plate 15 is directed upwardly, that is, the head of the screw 16. The back of the section is energized to support. The other structure is the same as that of the previous embodiment. In this embodiment as well, the same effects as in the previous embodiment can be obtained.

Furthermore, in this embodiment, the arm 14 is directly supported by the frame 2, so the structure can be made simpler. In each of the embodiments described above, the optical bench 3 is attached to the device exterior 11 via an elastic body, that is, a spring 17 or an elastic material 19 such as a sponge, but it is not necessary to have such a structure, and the arm 14 It is sufficient if the structure is such that it can be rotated to a certain extent or more.

Therefore, for example, it is also possible to have a structure in which the optical bench 3 is not attached to the device exterior casing 11 and the optical bench 3 is simply layered on the mounting rack exterior 11. However, if the optical bench 3 is attached to the device exterior 11 via an elastic body as in each of the above embodiments, the optical bench 3 may move carelessly on the device exterior 11 during transportation, and the lens 6 and There is no risk of damage to the image sensor 7 or incorrect installation or counterfeiting of the image sensor 7, and the rotation of the arm 14 is prevented when a moment is applied to the arm 14 around an axis perpendicular to the paper plane in FIGS. 3 and 5. The load on the moving shaft can be reduced.

As described above, the image reading device according to the present invention is provided with an arm that is rotatable around a virtual straight line that passes over the entire surface of the original in the main scanning direction, and this arm has a lens and an image sensor. By attaching the optical device, there is no need to increase the rigidity of the structural members of the device, making it possible to prevent distortion of the optical path without increasing the weight or manufacturing cost, and to make it easier to adjust the optical system. This provides an excellent effect of significantly shortening the time required.

[Brief explanation of drawings]

FIG. 1 is a side view of the main parts showing the image processing device of the present invention, and FIG. 2 is a side view of the main parts showing an embodiment of the image processing device of the present invention.
FIG. 3 is a plan view of this embodiment, FIG. 4 is a side view of essential parts showing another embodiment of the invention, and FIG. 5 is a plan view thereof. 2...Frame, 3...Optical bench, 6...Lens, 7...Image sensor, 8...Document, 11...Device exterior, 13... Virtual straight line, 14...
Arm, 17... Spring, 19... Elastic material. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A light source that irradiates the document, a lens that focuses reflected light from the light source from the document surface, a scanning device that receives the reflected light through the lens and performs photoelectric conversion, and An image reading device comprising: a support body rotatable about a virtual straight line extending in a scanning direction and holding the lens and the scanning means;