JPH04352123A - Read unit - Google Patents

Abstract

PURPOSE:To reduce the size and thickness of the un-magnified original read unit which is used for a copying machine, facsimile equipment, etc. CONSTITUTION:The read unit consists of a light emitting element 11 which irradiates a document 13, a light guide lens 17 which has an object-side lens part on one of surfaces arranged at right angles in a right-angled roof type prism shape and an image-side prism part 19 on the other surface, and also inverts and reflects an image of incident light from the object-side lens part 18 to a right-angle direction and guides it to the image-side lens part 19 by a roof surface 20 consisting of surfaces connecting end parts of the right-angle arranged surfaces, and a light receiving element 12 which receives the reflected light from the document 13; and the light emitting element 11 and light receiving element 12 are arranged on the same substrate 16 so that the object-side lens part 18 of the light guide lens 17 faces the document 13 and the image-side lens part 19 faces the light receiving element 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading unit, and more particularly to a same-size original reading unit used in copying machines, facsimile machines, and the like.

[0002] In recent years, office automation equipment such as copying machines and facsimile machines are becoming commonplace in homes.

[0003] Along with this, these devices are required to be convenient to carry and easy to assemble and maintain. It is desired to simplify the

0004

2. Description of the Related Art FIG. 5 is a block diagram of a conventional reading unit 1. The reading unit 1 is a facsimile reading unit using a gradient index optical fiber lens. In the figure, 2 and 3 are light emitting diodes, 4 is a gradient index optical fiber lens, 5 is a contact image sensor composed of a solid-state image sensor (CCD), an amorphous silicon element (α-Si semiconductor element), etc.
6 is a housing that holds each of the above devices.

[0005] The light emitted from the light emitting diodes 2 and 3 is irradiated onto the original 7, and the reflected light is incident on the contact type image sensor 5 via the gradient index optical fiber lens 4 to detect the information written on the original 7. The contents are converted into electrical signals.

Here, the gradient index optical fiber lens 4
has a cylindrical shape, with the highest refractive index at the center;
It has a parabolic refraction distribution that decreases toward the periphery. Since light has the property of bending in the direction of a higher refractive index, the light incident on the gradient index optical fiber lens 4 travels through the gradient index optical fiber lens 4 while drawing a sinusoidal curve with the same period. Using this principle, the length of the gradient index optical fiber lens 4 and the refractive index distribution are adjusted so that the image of the content written on the document 7 forms an erect, equal-magnification image on the contact image sensor 5. The distance from the molded optical fiber lens 4, etc. are selected.

[0007] In addition, in order to fabricate this graded index optical fiber lens 4, an element (thallium) that increases the refractive index is added to a glass rod whose main component is silicon or lead, and then the refractive index is increased. It is immersed in a molten liquid containing an element to make it smaller (potassium), and the ratio of the latter increases toward the periphery using an ion exchange method. In this way, a glass rod with a parabolic refractive index is formed. Thereafter, this is thinned into a fiber shape to obtain a gradient index optical fiber. Furthermore, by arranging these gradient index optical fibers in an array, a gradient index optical fiber lens 4 for the reading unit 1 is formed.

[0008]

[Problems to be Solved by the Invention] However, in the conventional reading unit 1, the gradient index optical fiber lens 4 is made of glass, so it is easily broken (mechanical strength is weak), and when arrayed, the lens In order to use it as a mirror, it is necessary to polish the cross section to a mirror-like surface, which poses a problem in that it is not possible to reduce costs.

In order to solve this problem, a refractive index gradient type optical fiber lens is also provided, which is made of plastic instead of glass and has a refractive index distribution similar to that described above. However, since the gradient index optical fiber lens 4 made of plastic cannot have a larger refractive index distribution than the gradient index optical fiber lens 4 made of glass, the distance between the original 7 and the gradient index optical fiber lens 4 is set to 10 mm or less. There was a problem that it could not be shortened to . Furthermore, since the central axis of reading the original 7 and the optical axis of the image formed by the gradient index optical fiber lens 4 coincide, it is possible to arrange the light emitting diodes 2 and 3 and the contact image sensor 5 on the same substrate. The problem was that it couldn't be done. Due to these problems,
In the conventional reading unit 1, it has been difficult to make the unit smaller and thinner.

The present invention has been made in view of the above points, and an object of the present invention is to provide a reading unit that can be made smaller and thinner.

[0011]

[Means for Solving the Problems] In order to solve the above problems, the present invention includes a light-emitting element that irradiates the document, a right-angled roof prism shape, and an object side on one of the surfaces disposed at right angles. The lens portion has an image-side lens portion on the other surface, and a surface connecting the end portions of the surfaces disposed at right angles inverts an image formed by incident light from the object-side lens portion and in the right angle direction. A reading unit is constituted by a light guide lens that is a roof surface that reflects light from the document and guides it to the image side lens portion, and a light receiving element that receives reflected light from the document and converts it into an electric signal, and the light emitting element and the light receiving element The elements are arranged on the same substrate, and the object-side lens part of the light guiding lens is arranged so as to face the document, and the image-side lens part is arranged so as to face the light-receiving element. be.

0012

[Operation] In the reading unit configured as described above, the optical axis from the document to the light receiving element can be bent by the light guiding lens, so it is possible to arrange the light receiving element and the light emitting element on the same board, and the reading unit can be made smaller and thinner.

Furthermore, the light guide lens includes an object side lens section and an image side lens section, and the magnification of each lens section can be set relatively easily. Therefore, even if the light guide lens is formed of resin having a lower refractive index than glass, the object side lens portion and the original can be brought close to each other, and this also allows the reading unit to be made smaller and thinner. In addition, by forming the light guide lens with resin, even a light guide lens having a complicated shape can be easily formed, and since it is hard to break, it can be easily formed into an array.

[0014]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a reading unit 10 which is an embodiment of the present invention.

In the figure, 11 is a light emitting element array, and 12 is a light receiving element array. The light emitting element array 11 is, for example, a light emitting diode (LED) or a fluorescent lamp, and is configured to irradiate light toward the original 13 through a condensing lens 14 . The light-receiving element array 12 is, for example, a solid-state image sensor (CCD) or an amorphous silicon element (α-Si semiconductor element), and reads the reflected light of the original 13 irradiated from a light guide lens 17 (described later), and converts it into the original 13. It generates electrical signals corresponding to the contents described. The reading unit 10 according to the present invention is characterized in that a light emitting element array 11 and a light receiving element array 12 are arranged on the same ceramic substrate 16. The reason why the light emitting element array 11 and the light receiving element array 12 can now be mounted on the same ceramic substrate 16 will be described later.

Reference numeral 17 denotes a light guide lens having a right-angled roof prism shape, and as shown in FIGS. 2 to 4 in addition to FIG. 20, a light shielding part 21, and the like. This light guide lens 17 forms an object side lens part 18 that enters light into one of the surfaces disposed at right angles in the shape of a right-angled roof prism, and an image side lens part 18 that emits light to the other surface. A portion 19 is formed. Further, a roof surface 20 is formed on the vertical front surface of the object-side lens section 18 and the image-side lens section 19, and is composed of two surfaces inclined at approximately 45 degrees with respect to the surface having the lens section. This roof surface 20 is formed only in a predetermined portion sufficient to reflect the light incident from the object-side lens portion 18 toward the image-side lens portion 19.

The light guide lens 17 has a structure in which transparent resin such as plastic is integrally formed in an array. By using a resin with a lower melting point than glass as the material for the light guiding lens 17, even the light guiding lens 17 having a complicated shape can be easily formed, and since it is difficult to break, it can be easily formed into an array. . Furthermore, by molding the light guiding lens 17 with resin, the magnifications of the object side lens section 18 and the image side lens section 19 can be set relatively easily. Therefore, even if the light guide lens 17 is made of resin having a lower refractive index than glass, the object side lens portion 18 and the original 13 can be brought close to each other, and the reading unit 10 can be made smaller and thinner.

[0018] Furthermore, the portion shown in matte finish in FIG. 3 is a light shielding portion, which is disposed in a portion excluding the lens portions 18, 19 and the roof surface 20, and prevents unnecessary light from entering the light guiding lens 17 from the outside. Preventing intrusion. This prevents disturbances from entering the signal generated by the light receiving element array 12 (note that FIGS. 2 and 3 show the arrayed light guide lens 17
(FIG. 4 shows one light guide lens 17).

Next, the optical path within the light guide lens 17 will be explained using FIG. 4. Light from the original 13 passes through the light guiding lens 17 from the direction indicated by arrow A in the figure to the object side lens section 1.
8. The light incident from the object side lens section 18 is 2
Among the roof surfaces 20, one of which is reflected by one roof surface 20a and incident on the other roof surface 20b, reflected again by this other roof surface 20b and directed toward the image side lens section 19, and this image side lens The light is emitted from the portion 19 to the outside of the light guide lens 17 . When passing through this roof surface 20, the image is reversed, and the image side lens section 19 emits the same image as the image incident on the object side lens section 18, that is, an erect, same-magnification image.

Returning to FIG. 1 again, the explanation will be continued. As described above, the optical path of the light incident from the object-side lens section 18 is bent within the light guide lens 17, but the direction is substantially perpendicular when viewed from the side shown in FIG. In this way, since the optical path is bent by the light guiding lens 17, it is no longer necessary to arrange the original 13 and the light receiving element array 12 in a straight line as in the conventional case, and this allows the light emitting element array 11 and the light receiving element array 12 to be placed close to each other. Each array 1
1 and 12 could be arranged on the same substrate 16. In addition, in the figure, 22 arranged between the light emitting element array 11 and the light receiving element array 12 is a light shielding plate, which prevents the light emitted by the light emitting element array 11 from leaking to the light receiving element array 12. be.

[0021]

As described above, according to the present invention, the optical axis from the original to the light receiving element can be bent by the light guiding lens, so it is possible to arrange the light receiving element and the light emitting element on the same substrate. The reading unit can be made smaller and thinner, and the light guide lens has an object-side lens section and an image-side lens section, and the magnification of each lens section can be set relatively easily. Even if the light guide lens is made of resin with a lower refractive index than glass, the object side lens part and the document can be brought close together, which also makes it possible to make the reading unit smaller and thinner. Since it is made of resin, it has the advantage that even a light guide lens having a complicated shape can be easily formed, and since it is hard to break, it can be easily formed into an array.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a reading unit that is an embodiment of the present invention.

FIG. 2 is a perspective view showing an array of light guide lenses.

FIG. 3 is a plan view showing an array of light guide lenses.

FIG. 4 is a diagram for explaining an optical path within a light guiding lens.

FIG. 5 is a configuration diagram showing an example of a conventional reading unit.

[Explanation of symbols]

10 Reading unit 11 Light emitting element array 12 Photo-receiving element array 13 Manuscript 14 Condensing lens 16 Board 17 Light guide lens 18 Object side lens section 19 Image side lens section 20, 20a, 20b roof surface 21 Light shielding part 22　Light shielding plate

Claims (3)

[Claims] [Claim 1] A light emitting element (1) that illuminates the original (13).
1), has a right-angled roof prism shape, has an object-side lens portion (18) on one surface of the surfaces arranged at right angles, and an image-side lens portion (19) on the other surface, and The object-side lens portion (18) is a surface that connects the ends of the surfaces to be arranged.
A roof surface (20,
20a, 20b) and a light guiding lens (17);
It is composed of a light-receiving element (12) that receives reflected light from the original (13) and converts it into an electrical signal, and the light-emitting element (11) and the light-receiving element (12) are mounted on the same substrate (16). At the same time, the object side lens part (18) of the light guiding lens (17) faces the original (13), and the image side lens part (19) faces the light receiving element (12). A reading unit characterized by being arranged as follows. 2. The reading unit according to claim 1, wherein the light guide lens (17) is made of integrally molded resin. 3. The light emitting element (11) on the substrate (16)
) and the light receiving element (12), the light emitting element (1
Claim 1 characterized in that a light shielding member (22) is provided to prevent the light of 1) from leaking to the light receiving element (12).
reading unit.