JPH0319752B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an image reading device such as a facsimile, an image reader, and a copying machine.

<Prior art> Recently, in order to make image reading devices such as facsimile machines and copying machines maintenance-free and smaller,
The number of devices using small sensors called close-contact image sensors, contact sensors, or 1-magnification sensors is gradually increasing. If the sensor did not make contact, the optical path length of the small sensor would change, causing the image to become out of focus, and there was a risk that it would not be possible to read the image clearly and clearly. Therefore, in view of these points, in the past, small sensors were held using highly accurate and sturdy mechanisms in order to keep them in constant contact with the reading platen roller, but these devices are complicated. However, it is inconvenient to assemble and handle, and has the drawbacks of high costs. Furthermore, the flatness of the table on which the user installs the image reading device cannot be guaranteed, so if it is installed on a table with poor flatness, the chassis of the main body will be distorted, and the mechanism that was configured accurately as described above may become distorted. However, it also had the disadvantage that it was not possible to guarantee solid contact between the small sensor and the platen roller.

<Problems to be Solved by the Invention> The present invention fundamentally improves these drawbacks of the conventional technology, and in particular, it has a very simple overall structure and can be installed on a table with no flatness. To develop a device that can ensure that a small sensor always makes solid contact with a platen roller even when the sensor is in contact with the platen roller.

<Means for Solving the Problems> In order to solve the above problems, the present invention provides a reading unit including a light source and a photoelectric conversion element, a cylindrical rotating body provided corresponding to the reading unit,
a biasing means for elastically bringing the reading unit into contact with the rotating body, the image light obtained by illuminating the original supported by the rotating body with the light source of the reading unit is read by a photoelectric conversion element. The image reading device includes support members that support both ends of the reading unit, one end of the reading unit is rotatably supported by the support member, and the other end is fixed to the support member. It is characterized by the fact that it is supported by

<Embodiment> An embodiment of the apparatus according to the present invention will be specifically described with reference to the drawings. In FIG. Pick-up roller 3 operated by
Thus, the sheet is configured so that it can be conveyed to the reading platen roller 5, which constitutes the next cylindrical rotating body, through the space between the lower guide 2 and the upper guide 4. Reference numeral 6 denotes a paper feed guide that is pressed against the lower surface of the platen roller 5 via a pressure spring 6a, and a detection sensor 7 that can detect the leading edge of the document 1 is attached to the side thereof. Next, 8 is a small sensor which is a reading unit, and its both ends are connected by a rotary sensor arm 10 and a fixed sensor arm 10a, which can rotate around a support shaft 9 that is pivoted on the chassis of the main body. Supported.

Next, the small sensor 8 and this small sensor 8
The relationship between the arms 10, 10a supporting the platen roller 5 and the platen roller 5 will be described in detail as follows.
That is, as is particularly clear from FIGS. 2 to 4, one shaft end of the small sensor 8 is pivoted to the rotary sensor arm 10 via a single support shaft 11 so as to be able to swing around this support shaft 11. The other shaft end is completely fixed to the fixed sensor arm 10a at two locations with screws 12.

Reference numeral 13 denotes an urging spring for bringing the small sensor 8 into contact with the platen roller 5, and above the platen roller 5, a paper discharge guide 15 is provided which is pressed against the platen roller 5 by a pressure contact spring 14. Further, 16 is a discharge port for the original 1.

<Function> As described above, the device according to the present invention supports the small sensor 8 by the rotary sensor arm 10 that can rotate around the support shaft 9 and the fixed sensor arm 10a, and also supports one part of the small sensor 8. The side end is pivotally attached to the rotation sensor arm 10 so as to be able to swing around the support shaft 11, and the other end is fixed to the fixed sensor arm 10a. As shown, the fixed sensor arm 10a
The small sensor 8 located on the side is connected to the platen roller 5.
Even if there is a gap between the small sensor 8 on the rotation sensor arm 10 side and the platen roller 5 when the small sensor 8 is brought into contact with the rotation sensor arm 10 , the rotation sensor arm 10 will be able to maintain its position on the support shaft 9 due to the weight of the small sensor 8 and the action of the biasing spring 13 . Since the small sensor 8 rotates around the support shaft 11 and also swings around the support shaft 11, the small sensor 8 can be automatically and constantly brought into contact with the platen roller 5 in a solid manner. Therefore, even if the table on which the device is installed is not flat, the small sensor 8 can be automatically brought into full contact with the platen roller 5.

Next, an example of the small sensor 8 will be described.

As shown in FIG. 5, the small sensor 8 irradiates light onto the reading surface using an illumination mechanism a made up of an LED array, etc., forms an image using an imaging mechanism b made up of a rod lens array, etc., and also uses a photodiode. It is constructed so as to convert it into an electrical signal using a photoelectric conversion element c consisting of an array or the like, and each of the above-mentioned mechanisms is constructed so as to span the entire width direction of the original 1 as shown in FIG. By using such a small sensor 8, it is possible to read the document 1 in the width direction at once, and the optical path length can be reduced to about 10 mm to 30 mm.
Therefore, as conventional photoelectric conversion elements that had to ensure a total optical path length of about 300 mm, CCD and MOS
It is much smaller than when using a type of IC image sensor, etc. Furthermore, the imaging mechanism b of the small sensor 8 may be omitted, and in this case, the distance H between the original 1 and the photoelectric conversion element c can be further reduced, and the size can be reduced. Further, the illumination mechanism a may be provided on both sides of the imaging mechanism b, as shown in FIG. Here, an example of reading a JIS standard A4 size original ₁ using the small sensor 8 will be explained. As shown in FIG.
A4 size document width L ₂ = 210mm, reading width L ₃ = 208mm
All you have to do is read the degree to the same size.

<Effects of the Invention> Since the device according to the present invention has the above-described structure, the small sensor can be brought into constant contact with the platen roller over the entire axial direction of the platen roller, especially on the stand on which the device is installed. Even when the platen roller is not flat, the small sensor can be automatically aligned with the platen roller and brought into full contact with the platen roller, thereby preventing out-of-focus phenomena and improving the image quality. It is possible to clearly read the entire surface, and since the entire mechanism is extremely simple, there are few failures, it is easy to handle, and it can be mass-produced at low cost.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional diagram of the entire device, Figure 2 is a diagram of its main parts, Figures 3 and 4 are perspective diagrams of its main parts, and Figures 5 and 6 are diagrams of a small sensor. It is. 5 is a platen roller, 8 is a small sensor, 9,
11 is a support shaft, 10 is a rotation sensor arm, 10a
is a fixed sensor arm, and 13 is a spring.

Claims (1)

[Claims] 1. A reading unit including a light source and a photoelectric conversion element, a cylindrical rotating body provided corresponding to the reading unit, and an attachment that brings the reading unit into elastic contact with the rotating body. In an image reading device that illuminates a document supported by the rotary body with a light source of the reading unit and reads image light obtained by using a photoelectric conversion element, the image reading device includes a means for supporting both ends of the reading unit, respectively. An image reading device comprising: a support member, wherein one end of the reading unit is rotatably supported by the support member, and the other end is fixedly supported by the support member.