JPH04326655A - Nonmagnification reader - Google Patents

Abstract

PURPOSE:To attain miniaturization and high performance of the nonmagnification reader. CONSTITUTION:The reader is provided with a nonmagnification image forming lens 5 formed by adhering 1st and 2nd lenses 5a, 5b in which plural spherical convex lenses with a light shield layer formed between them regularly while the lenses are made respectively correspondent, an original platen 3 whose thickness is set and adhered with the nonmagnification image forming lens 5 so that the focus of the nonmagnification image forming lens 5 comes to the original placing face, a light source 1 lighting the original face and a photoelectric conversion means 6 arranged opposite to the light source 1 via the original platen 3 and the nonmagnification image forming lens 5. Then an image of the original face is formed on the photoelectric conversion means 6 with nonmagnification and the original is read while being moved in the subscanning direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a same-magnification reading device that optically scans the surface of a document and converts information recorded on the document into an electrical signal and outputs the electric signal.

0002

2. Description of the Related Art In recent years, full-magnification reading devices have been widely used, mainly in facsimile machines, due to advances in same-magnification reading sensors and same-magnification optical systems.

Conventionally, most of these same-magnification reading devices have been constructed using a SELFOC lens array as the same-magnification imaging lens, and most of the products sold as products use this SELFOC lens array. It's safe to say that there are. Therefore, although its configuration is not shown in the drawings, it has a shorter optical path length than a reduction type optical system, making it possible to miniaturize the device, but on the other hand, it has a shallow depth of focus and limited resolution (reading performance is 400D).
There were problems such as PI being limited.

Although it is said that the optical path length will be short especially when a resolution close to 400 DPI is required, the optical path length will be about 40 mm to 70 mm, and when reading by moving the optical system, the space for this will increase and the device will be large. Because of this problem, most full-size reading devices have a structure in which the document moves and the optical system is fixed.

[0005] Furthermore, as a conventional 1x reading device, an apparatus using a 1x optical system having characteristics as shown in FIGS. 8 to 11 has been proposed.

An example of the above-mentioned conventional same-magnification reading device will be described below with reference to the drawings.

FIG. 8 shows the optical system of a conventional 1x reading device. In FIG. 8, 100 is a document. 10
Reference numeral 1 denotes a document mounting table made of glass; 102a is a first lens; 102b is a second lens; and 102c is a third lens.
03 at the same magnification. A non-reflective baffle plate 104 and a field stop aperture 105 are provided between the first lens 102a and the second lens 102b, and are configured to prevent light from coming from an adjacent lens.

The optical system of the same-magnification reading device configured as described above includes a first lens 102a and a second lens 102b.
There is a problem in that it is difficult to manufacture the non-reflective baffle plate 104 and the field stop aperture 105 constructed between the two lenses, and to uniformly manufacture each of the first, second, and third lenses. (Japanese Patent Publication No. 49-8893) Also, as shown in FIG. 9, a method has been proposed in which a first lens 110 and a second lens 111 are used to form an image at the same magnification. It has not been put into practical use as a product because it is difficult to manufacture as it requires combining and integrating. (Japanese Patent Publication No. 61-33174) Furthermore, as shown in FIGS. 10 and 11, a 1-magnification reading device has been proposed in which a 1-magnification imaging optical system is constructed by combining a right-angle mirror 121, a lens array 122, and a roof mirror 123. However, it is necessary to solve the above-mentioned problems for commercialization, such as making the optical characteristics of the lens array uniform and making the entire optical system complicated and difficult to assemble.

(Japanese Unexamined Patent Application Publication No. 60-245357)

0
010]

[Problems to be Solved by the Invention] However, with the above configuration, it is difficult to equalize the characteristics of the lenses constituting the 1-magnification imaging optical system and to assemble them. However, due to resolution limitations and shallow depth of focus, self-hock lens arrays cannot be used in reading devices that require high resolution or deep depth of focus. It had

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a same-magnification reading device that has a simple structure, is compact, and has high performance.

0012

[Means for Solving the Problems] In order to solve the above-mentioned problems, the same-magnification reading device of the present invention includes a first lens in which a plurality of regularly formed spherical convex lenses each having a light shielding layer between the lenses; A second lens is formed by forming a plurality of spherical convex lenses with a light shielding layer therebetween so that the pitch between the lenses is the same as that of the first lens, and bonded to the first lens so that the lenses correspond to each other. A 1-magnification imaging lens, a document mounting table whose thickness is set so that the document placement surface is positioned at the focal position of the 1-magnification imaging lens, and a document mounting table that is made up of a 1-magnification imaging lens and a stacked original. A light source is provided at a predetermined distance from the document placing table on the side facing the document placing table to illuminate the document from the back side, and a photoelectric source is placed at the focal point of the same magnification imaging lens, facing the front magnification lens. This device has a configuration in which reading is performed at the same magnification using a converting means.

[0013]

[Operation] The present invention uses a thin equal-magnification imaging lens with the above-described structure, attaches the equal-magnification imaging lens to the document table, and further positions the focal point on the document table to transmit document information to an electrical signal. It is possible to convert and output the image into a 1:1 image, thereby making it possible to reduce the size and improve the performance of the 1x reading device.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A full-size reading device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a side sectional view of a full-magnification reading device according to an embodiment of the present invention. In FIG. 1, 1 is a light source, 2 is an original transport roller, and 3 is an original placing table. light source 1
is a fluorescent lamp that enters inside the document conveying roller 2 and illuminates the document 4 over the reading main scanning width. The document transport roller 2 is a transparent cylindrical roller 2a made of glass or acrylic, and a thin light-transmitting rubber 2 such as silicone rubber is attached to the outer periphery of the roller 2a.
b, which is rotatably driven in the direction of arrow A (not shown) by a driving means such as a motor, and conveys the original 4 while being sandwiched between it and the original placing table 3. The original 4 is made of a light-transmissive original such as an OHP. Reference numeral 5 denotes a same-magnification imaging lens, which is composed of a first lens 5a and a second lens 5b. The first lens 5a and the second lens 5b are manufactured in a similar manner. First, a special photosensitive glass material is masked and exposed to ultraviolet light. When heat treatment is performed after irradiation with ultraviolet rays, the portions exposed to ultraviolet rays crystallize and shrink, forming spherical portions that were not exposed. Further heat treatment makes the exposed portion opaque, forming a light shielding layer 5c, and easily forming a large number of spherical lenses with uniform optical properties. The first lens 5a and the second lens 5b manufactured in this manner are bonded together with an adhesive 5d in correspondence with each other to form the same-magnification imaging lens 5. Incidentally, optical characteristics such as depth of focus and focal length can be arbitrarily set by the above-described manufacturing conditions, lens thickness (thickness of photosensitive glass material), and interval setting between the first and second lenses. The same-magnification imaging lens 5 is attached to the original table 3 by adhesively bonding its periphery with an adhesive 5d. By adhering the 1-magnification imaging lens 5 to the document mounting table 3 in this way, it provides mechanical strength to the 1-magnification imaging lens 5, which is extremely thin and has a thickness of around 1 mm, and also maintains a stable distance to the original. This makes it possible to perform highly accurate reading. 6 is a photoelectric conversion means; 7 is a base for mounting the photoelectric conversion means;
8 is a mounting means. The photoelectric conversion means 6 is a contact type photoelectric conversion means such as a CCD, and is constructed by arranging a plurality of photoelectric conversion elements in a row in the main scanning direction. Photoelectric conversion means 6
is attached to the base 7 by attachment means 8. Further, the base 7 and the same-magnification imaging lens 5 are bonded together with an adhesive 5d. The photoelectric conversion means 6 is constructed of a glass plate using a Cds-Se thin film structure that can be manufactured, and the glass plate is directly adhered to the same-magnification imaging lens 5, thereby attaching the base 7 and the mounting means. It is also possible to eliminate the number 8. The document conveying roller 2 and the document mounting table 3 may be configured to be able to be pressed into contact with each other and separated from each other.

The operation of the same-magnification imaging device constructed as described above will be explained below with reference to FIG.

First, when the original 4 is conveyed by rollers (not shown) to the contact position between the original placing table 3 and the original transport roller 2, the original transport roller 2 is rotated in the direction of arrow A, and at the same time the light source 1 is turned on. Light. Here, the light transmitted through the original is formed into a 1-magnification image on a photoelectric conversion means 6 by a 1-magnification imaging lens 5 . Further, while conveying the original 4, it is electrically scanned in the main scanning direction by the photoelectric conversion means 6, and the original 4 is sequentially read, converted into an electric signal, and output.

As described above, according to this embodiment, the reading of a transparent original in the original moving method is performed using the first lens 5a and the second lens 5a.
By bonding the 1-magnification imaging lens 5 with the lens 5b bonded to the document mounting table 3, it is possible to easily create a high-performance 1-magnification reading device with a short optical path length (distance from the document surface to the photoelectric conversion means). This can be obtained with a simple configuration.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a side view of a same-magnification reading device showing a second embodiment of the present invention.

In the figure, 1 is a light source, 4 is a document, and 6 is photoelectric conversion means, which are the same as in FIG.

The difference from FIG. 1 is that the original table 3' is
The point is that it is configured to be larger than the original 4 so that it can be read in a fixed manner. Accordingly, the equal-magnification imaging lens 5' is also configured to be larger than the original 4. FIG. 3 is a plan view showing the equal-magnification imaging lens 5' and the original table 3'. As shown in FIG. 3, the main scanning width B and the sub-scanning width C are wider than each other, and the periphery is bonded with an adhesive portion 5'd. Also, when bonding the document mounting table 3' and the equal-magnification imaging lens 5', the air between the document mounting table 3' and the equal-magnification imaging lens 5' is removed to reduce the pressure. ' is arranged along the front surface of the document table 3'.

The operation of the same-size reading device configured as described above will be explained below. First, the original 4 is set on the original placing table 3'. Next, the light source 1 is turned on, and the light source 1 and the photoelectric conversion means 6 are synchronized with a suitable moving means (not shown) and moved in the direction of the arrow F, and the originals 4 are sequentially read.

As described above, the original placing table 3' has a larger area than the original 4 so that the original 4 can be fixed and read, and the equal-magnification imaging lens 5' has an area larger than the original 4 and is attached to the original placing table 3'. By bonding and integrating the document, the document can be fixed and read. Since the document can be read while being fixed, the transparent document will not be damaged. Even if the 1-magnification imaging lens is configured with a wide area, the 1-magnification imaging lens 5' can be manufactured easily and uniformly even over a large area using the manufacturing method described above. There are no problems with manufacturing. Further, since the moving part can be used as a light source and a photoelectric conversion means, a high-performance and simple 1x reading device can be obtained.

A third embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a side view of a same-magnification reading device showing a third embodiment of the present invention.

In the figure, the document mounting table 3', the same-magnification imaging lens 5', and the document 4 are the same as those in the second embodiment, and their explanation will be omitted.

The difference from FIG. 2 is the structure of the document illumination and the area photoelectric conversion means 11'. 9 is a light diffusing plate, and 10 is a light source. The light sources 10 are made of fluorescent lamps, cold cathode tubes, etc., and are provided on both sides of the light diffusing plate 9. The light diffusing plate 9 irradiates the entire document placement range of the document placement table 3' with light incident from both sides. FIG. 5 shows a perspective view of the light source 10 and the light diffusing plate 9.

As shown in FIG. 6, the area photoelectric conversion means 11' is constructed by forming a thin film of a Cds-Se photoelectric conversion element 11'a on a transparent glass substrate 11'b. Further, in the area photoelectric conversion means 11', a photoelectric conversion element 11'a is formed corresponding to the entire document reading range, and an equal-magnification imaging lens 5
' and the periphery outside the reading range are glued together to integrate the document mounting table 3' and the same-magnification imaging lens 5'. In addition, as shown in FIG. 7, signals can be sequentially output by wiring in an n×m matrix and driving in a matrix.

The operation of the same-size reading device configured as described above will be explained below. First, the original 4 is placed on the original placing table 3' and the light source 10 is turned on to illuminate the entire surface of the original through the light diffusing plate 9. Next, area photoelectric conversion means 11
' is driven in a matrix to sequentially read the original and output it as an electrical signal.

As described above, according to this embodiment, by providing the light source and the photoelectric conversion means in a planar manner, it is possible to eliminate the movable part and obtain a highly reliable, simple structure, 1-magnification reading device.

In the first embodiment, the equal-magnification imaging lens 5 and the base 7 are glued together to form an integral structure, but they may be constructed separately.

In the third embodiment, the original is illuminated by the light source 10 and the light diffusing plate 9, but the LE
A D element may be arranged to provide a surface light source, or a plurality of fluorescent lamps may be used to directly illuminate a surface.

Furthermore, in the third embodiment, Cds-S
Area photoelectric conversion means 1 by photoelectric conversion element 11'a of e.
1', the photoelectric conversion element 11'a may be composed of amorphous silicon, CCD, or the like.

Further, in the third embodiment, a light source capable of illuminating in a planar manner and an area photoelectric conversion means are used, but the photoelectric conversion means is an area photoelectric conversion means and the light source is a linear illumination that is moved in the sub-scanning direction for reading. It goes without saying that the configuration may be configured or vice versa.

[0034]

Effects of the Invention As described above, the present invention provides a first lens which has a plurality of regularly formed spherical convex lenses with a light shielding layer between the lenses.
A 1-magnification imaging lens bonded with a second lens; and a document placement stand bonded to the 1-magnification imaging lens with the thickness set so that the focal position of the 1-magnification imaging lens is on the document placement surface. By providing a light source that illuminates the document surface and a photoelectric conversion means, it is possible to reduce the size and improve the performance of the same-size reading device with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a same-magnification reading device in a first embodiment of the present invention.

FIG. 2 is a side view of a same-magnification reading device in a second embodiment of the present invention.

FIG. 3 is a plan view showing a document mounting table and a 1-magnification imaging lens in a second embodiment of the present invention.

FIG. 4 is a side view of a same-magnification reading device in a third embodiment of the present invention.

FIG. 5 is a perspective view showing a light source and a light diffusing plate in a third embodiment of the present invention.

FIG. 6 is a side sectional view of a main part of a third embodiment of the present invention.

FIG. 7 is a configuration diagram showing area photoelectric conversion means in a third embodiment of the present invention.

FIG. 8 is a side view showing a conventional example.

FIG. 9 is a perspective view showing another conventional example.

FIG. 10 is a perspective view showing another conventional example.

11 is a side sectional view of the conventional example shown in FIG. 10. FIG.

[Explanation of symbols]

1. Light source 2 Original transport roller 3, 3’ Original table 5, 5’　1-magnification imaging lens 6, 6' Photoelectric conversion means 11 Area photoelectric conversion means

Claims (5)

[Claims] 1. A first lens including a plurality of regularly formed spherical convex lenses each having a light blocking layer between the lenses, and a plurality of spherical convex lenses each having a light blocking layer between the lenses at a pitch between the first lens and the lens. a 1-magnification imaging lens consisting of a second lens that is formed so that they are the same and is bonded to the first lens so that the lenses correspond to each other, and a second lens that is bonded to the 1-magnification imaging lens and the like; A document placing table having a thickness set so that the document placing surface is located at the focal position of the double imaging lens, and a document placing table having a predetermined distance from the document placing table on the side facing the document placing table through the document. a light source provided to illuminate the document from the back surface thereof; and a photoelectric conversion means provided at a focal position of the same-magnification imaging lens and facing each other through the same-magnification imaging lens. reading device. 2. A full-magnification reading device characterized in that the light source is a surface light source so as to illuminate at least the entire reading range. 3. A same-magnification reading device characterized in that the photoelectric conversion means is an area photoelectric conversion means formed over the entire reading range. 4. The same-magnification reading device according to claim 3, wherein the photoelectric conversion means is composed of Cds-CdS. 5. A life-size reading device, characterized in that the life-size imaging lens has an area that can image at least the entire reading range at the same time.