JPS6224984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for reading out information on a document surface such as calligraphy and drawings.

Various reading devices that use photoelectric conversion have been proposed as image information reading devices for facsimile machines, laser beam printers, inkjet printers, etc., but in recent years, advances in image processing devices have made it possible to read images with high resolution. There is a strong desire for the emergence of a device capable of reading multiple information such as color information with high resolution.

The present invention was developed in response to such demands.

In the embodiments of the present invention, a high-resolution one-dimensional light-receiving sensor array is used as a light-receiving sensor, and the length of the sensor unit in the array direction can be manufactured from long to short.
- Thin film photo sensors such as Te amorphous semiconductors and Si amorphous semiconductors can be applied, which exhibit excellent photoelectric conversion characteristics in the visible wavelength region, and can be easily made into long lengths using vacuum evaporation methods. . Although it is a thin film, it has a fast response speed and is chemically stable in air.

FIG. 1 is a diagram illustrating a one-dimensional light-receiving sensor array 1 using the above-mentioned amorphous semiconductor, in which the amorphous semiconductor 2 of the thin film photo diode is connected to a transparent electrode 3 and metal electrodes 4 and 5 as bonding terminals. They are sandwiched together to form one sensor unit a, and a plurality of the units a are arranged in an array across the width of the document to form one one-dimensional light receiving sensor array 1. The array 1 shown in the figure shows an amorphous semiconductor 2 and a metal electrode 5 formed as a single continuous layer common to each sensor unit a.

In this specification, the array direction of each sensor unit a is defined as a main scanning direction, and the direction perpendicular to the main scanning direction is defined as a sub-scanning direction.

When the light L enters the light receiving sensor array, only the portion of the amorphous semiconductor 2 that receives the light through the transparent electrode 3 in each sensor unit a is photoelectrically converted according to the amount of light received, and the information is controlled by the drive circuit 6. The output signal is taken out to the outside by the switching circuit 7 that has been switched. In this way, one line of manuscript information is
It can be extracted from the one-dimensional light receiving sensor array 1 as a time series signal.

Therefore, by forming the light-receiving sensor array 1 with the length of the document width and performing main and sub-scanning of the document surface with a one-to-one correspondence between the light-receiving sensor array and the document surface, information on the entire document surface can be read. things are possible.
In that case, the pitch between each sensor unit a of the light-receiving sensor array 1 determines the resolution when reading the original. Therefore, in order to read the fine details faithfully to the original, it is necessary to make the pitch between each unit a as small as possible.

However, since such a light-receiving sensor array is manufactured by vacuum evaporation, the arrangement density of sensor units is currently limited to approximately 8 units per 1 mm due to mask patterning, manufacturing methods, etc. Furthermore, even if a light-receiving sensor array could be realized with a fine unit pitch, the light-receiving area of each unit a would be extremely small, resulting in a decrease in sensitivity.

Furthermore, when reading color image information by installing a color stripe filter on the light receiving surface, a set of two or three sensor units becomes the reading unit that determines the resolution, so the resolution is kept at the same level as in the case of non-color images. In order to achieve this, even finer unit pitches are required. Therefore, this case also has the same problem of reduced sensitivity as the above case.

The present invention solves these problems and enables high-resolution reading or color information reading while maintaining a large light-receiving area of each light-receiving sensor unit.

Figures 2A and 2B are views showing the first embodiment of the device of the present invention, and Figure 2A is a schematic perspective view of the entire device, and Figure 2B is a schematic perspective view of the entire device.
is a cross-sectional view of the device. This embodiment device has 10 originals.
A cylindrical lens 12 for forming a line light source image of a line light source 13, which has a generatrix in the main scanning direction and is provided parallel to the main scanning direction, on the surface of the original 10. and two (two rows) one-dimensional light receiving sensor arrays 1 arranged in the main scanning direction on both sides of the cylindrical lens 12.
₁ , 1 ₂ , and these members 11, 1
2, _{1 1} , 1 ₂ , and 13 are combined and integrated with each other.

In this embodiment, the linear light source 13 is preferably as thin as possible in order to increase the resolution in the sub-scanning direction, and a halogen light source in the form of a linear light source or a xenon light source with a small tube diameter can be used. It is preferable to use a wear-resistant material with good adhesion, and it is also possible to provide a curvature on the surface in contact with the original 10 in order to improve the adhesion with the original 10.

Also, simply a linear light source 13 and a cylindrical lens 1
If it is difficult to provide narrow line illumination by simply illuminating the 10 sides of the original with 2 and 2, the reading width may be regulated by making a slit of the required width on the 10 sides of the original.

2 arranged on both sides of the cylindrical lens 12
Both of the light receiving sensor arrays 1 ₁ and 1 ₂ of this book have approximately the same configuration as shown in FIG. 1, and as shown in FIG. 3, 8, metal electrodes 4, 5 connected to the transparent electrodes 3, 8, and opaque insulators 9, 9 for blocking light directly entering the amorphous semiconductors 2, 2 from the light source 13. Become. 2 in this example
The light-receiving sensor arrays 1 ₁ and 1 ₂ of the book are constructed with transparent electrodes 3 and 8 as a common continuous layer connecting both arrays 1 ₁ and 1 ₂ , so the metal electrodes 4 and 5 for signal extraction are connected to the two light-receiving sensors. The terminals 4 ₁ , 5 1 of each of the metal electrodes 4 , 5 need only be provided on either side of the array _{1 1 ,} 1 ₂ and the switching circuit 7
(Fig. 1).

In an apparatus having such a configuration, illumination light from a linear light source 13 disposed directly above or in the vicinity of a cylindrical lens 12 for condensing light is condensed by the cylindrical lens 12 and mainly illuminates the 10th side of the original. Line illumination in the scanning direction. Of the original reflected light of the illumination light, the direct reflected light, which is non-information light, passes through the cylindrical lens 12 again and is removed, and the scattered light, which is information light, is transmitted to each of the light receiving sensor arrays 1 ₁ , 1 ₂ on both sides of the cylindrical lens 12 . The light enters each sensor unit through the lower transparent electrode 8. Reading in the same direction is performed by time-series scanning of the light receiving sensor arrays 1 ₁ and 1 ₂ in the main scanning direction, and furthermore, by relatively moving the device and the original 10 in the sub-scanning direction, the original is read. A full reading is done. Note that means for relatively moving the device and the document are not shown.

In this way, in this embodiment, it is possible to efficiently sense the information light from the 10 sides of the document and read the information with an integrated compact device.However, by taking the following measures, The resolution can be further increased.

That is, the first treatment is to place light receiving sensor arrays 1 ₁ , 1 ₂ in a transparent carrier 11 as shown in FIG.
By arranging the light-shielding stoppers ₁₁₁ perpendicular to the main scanning direction in an arrangement corresponding to each sensor unit in the main scanning direction, the resolution in the main scanning direction can be improved. If the thickness of the transparent carrier 11 is thin, the resolution in the main scanning direction is determined by the size and pitch of each sensor unit in the light-receiving sensor arrays 1 ₁ , _{1 2} . A sensor array 1 ₁ that receives information light from a surface;
1 to each sensor unit in ₂ without confusion, and prevent a decrease in resolution due to optical crosstalk where information light from one point on the document enters multiple adjacent sensor units due to scattering of information light. In addition, by making one surface of the light shielding stopper _{11 a} reflective surface, it is possible to increase the amount of light incident on each sensor unit. In addition, each light shielding stopper 1
The pitch of ₁₁ is also effective even if the pitch is thinner than the pitch of each sensor unit in the light receiving sensor arrays ₁₁ and ₁₂ .

The second method is to divide the amorphous semiconductor elements 2, ₂ in each of the light receiving sensor arrays ₁₁ , 12 into each sensor unit using a patterning method such as etching. Prevent signal mixing.

The third measure is to adjust the thickness of the transparent carrier 11 and the width of the cylindrical lens ₁₂ in the sub-scanning direction _.
The amount of light received is increased by lengthening each sensor unit in the sub-scanning direction. Generally, in order to increase the amount of light received, it is sufficient to increase the solid angle at which the illumination point looks up to the light receiving surface of the light receiving sensor unit. This can be achieved by moving the surface closer to the illumination point and widening the light receiving area of the light receiving sensor unit. In this case, the length of the light receiving sensor unit in the sub-scanning direction does not affect the resolution in the main scanning direction, so by increasing the length of the light receiving sensor unit and increasing the amount of light received, the pitch of each light receiving sensor unit in the main scanning direction can be made narrower. The aim is to improve resolution by making it possible to
However, secondary and tertiary reflected light between the document surface and the light receiving sensor surface becomes noise, so making it unnecessarily long in the sub-scanning direction will only increase the noise, but it is recommended to provide an anti-reflection coating on the light receiving sensor surface. This noise can be prevented to some extent.

Two rows of light receiving sensor arrays 1 provided on both sides of the cylindrical lens 12 in the device shown in FIG.
₁ , 1 ₂ are each array 1 as shown in FIG. 4A.
The sensor units _a , 1 and ₂ are arranged in parallel with each other, and the two units a and a facing each other in the sub-scanning direction are connected to each other by transparent electrodes 3 and 8 as shown in FIG. 2B. This substantially enlarges the light-receiving surface of the sensor unit and increases the sensitivity of the device.

In addition, as shown in FIG. 4B, two rows of light receiving sensor arrays 1
By arranging the sensor units a of ₁ , 1, and ₂ in a staggered manner so as to compensate for the non-reading portions of both the light receiving sensor arrays ₁₁ and ₁₂ , one row of light receiving sensor arrays can be arranged. It is possible to obtain nearly twice the resolution. In this case, the pitch of the electrode structure provided in each sensor unit may be 1/2 of the required resolution, which is advantageous in terms of device fabrication and sensitivity.

In the case of FIG. 4B, the opposing sensor units a and a of each array 1 ₁ and ₁₂ are not communicated with each other and read information as individual sensor units. That is, the electrode terminals of the individual sensor units in each array 1 ₁ , 1 ₂ are alternately connected to one switching circuit, or each array 1 ₁ , 1 ₂ is connected to a switching circuit provided separately. A time-series read signal is obtained by connecting and later combining the signals.

FIG. 4C shows an example in which a color reading filter is further provided on the surface of each light-receiving sensor array 1 ₁ , 1 ₂ in FIG. 4B described above to enable reading of color information. That is, on the surface of one light-receiving sensor array ₁₂ , each sensor unit a
Filters Y for luminance signals are installed in correspondence with the sensor units A, and stripe filters for red R and blue B color signals are alternately installed on the surface of the other light-receiving sensor array ₁₁ in correspondence with each sensor unit a. . Using this embodiment, it is possible to read color information with a resolution almost as high as that of a conventional one-row light-receiving sensor array. Furthermore, in the arrangement shown in FIG. 4C, a filter of line G is provided on the surface of one of the light receiving sensor arrays ₁₂ for brightness signals, and a filter of line G is arranged alternately on the surface of the other light receiving sensor array ₁₁ .
B), -B (=G+R) color filters are provided and the information signals are read, both light receiving sensor arrays 1 ₁ ,
Since the signals output from each sensor unit a of 1 _{and 2} include a luminance signal, applying the signal processing system of a normal color television can obtain color information while still providing the same level of information as in the case of the example B in Fig. 4 above. High resolution can be obtained.

In addition, as _{shown in FIG} .
Color information can be obtained by installing green (G), blue (B), and red (R) color filters on the surfaces of sensors ₁ , ₁₂ , and _13, respectively, and reading the signals from each sensor unit a independently. .

A reading device that can simultaneously detect information light from an illuminated line by arranging two or more rows of one-dimensional light receiving sensor arrays 1 ₁ , 1 ₂ , 1 ₃ on one side or both sides of the cylindrical lens 12 is equipped with a sub-array. The document surface and the light receiving sensor surface are not in an optically conjugate relationship in the scanning direction. In that case, by arranging a plurality of n one-dimensional light receiving sensor arrays in which units a are arranged at the same pitch P in n rows in the double scanning direction while sequentially shifting them by P/n in the main scanning direction, all the arrays can be Each sensor unit a in can detect information light from the corresponding illumination line,
Furthermore, a reading device with a resolution nearly n times higher can be obtained.

Next, the second embodiment device will be explained with reference to FIGS. 5A to 5D. The device of this example has a higher resolution and is made more compact. In order to increase the resolution, it is possible to form an image of the document surface on the light-receiving sensor surface, but if an ordinary optical system with only one optical axis is used as the imaging system, the conjugate distance will be long, making it compact. It cannot be used as a device.
This embodiment solves the above problems by using compound lenses.

That is, when a compound eye lens system is used, the conjugate distance can be shortened by that much, and as a result, the amount of light on the image plane increases, and reading unevenness can also be eliminated by increasing the number of lenses. However, when it becomes possible to shorten the conjugate distance, what becomes a problem in making the device more compact is the means for taking in the illumination light.
In other words, in order to read the document surface with high sensitivity, it is necessary to take in sufficient illumination light, and to do so, it is necessary to maintain a sufficient space between the device and the document surface, which impedes further compactness. Therefore, in this embodiment, in order to solve the above-mentioned difficulties, illumination light is introduced directly through the compound eye lens. However, in order to prevent illumination light from being affected by the condensing and diverging effects of the compound lens and causing uneven illumination, a generatrix perpendicular to the main scanning direction is used as a compound lens to be placed between the illumination means and the document surface. A cylindrical lens array body is used.

That is, the apparatus shown in the example of FIG. 5 has a plurality of unit cylindrical lenses ₁₄₁ having a smooth lower surface that contacts the surface of the original 10 and a generatrix parallel to a predetermined sub-scanning direction on the upper surface, which are sequentially arranged in parallel in the main scanning direction. The formed first cylindrical lens array 14, a second cylindrical lens array 15 having the same configuration as the first cylindrical lens array 14, which is disposed facing above the lens array 14 with the convex side of the lens facing downward, and both of them. Between the lens arrays 14 and 15, there is a light shielding plate array 16 perpendicular to the main scanning direction arranged so as to partition each unit cylindrical lens ₁₄₁ individually, and a light shielding plate array 16 arranged on the upper smooth surface of the second cylindrical lens array. A condensing cylindrical lens 12 having a generatrix in the main scanning direction, and a second cylindrical lens array on both sides of the lens 12.Two rows of primary lenses arranged in an array in the main scanning direction are arranged on the upper smooth surface of the second cylindrical lens array. Original light receiving sensor array 1 ₁ ,
1 ₂ , and a linear light source 13 disposed directly above or near the condensing cylindrical lens 12 (Fig. 5C).
It consists of and. These members are combined and integrated.

In the above, each one-dimensional light receiving sensor array 1 in two rows
₁ , 1, _{and 2} have the same configurations as those shown in FIG. 2B, so a detailed explanation thereof will be omitted here. Further, the light shielding plate array 16 serves to prevent optical crosstalk.

The reading process in an apparatus with such a configuration will be explained with reference to FIG. Therefore, the light is condensed to illuminate the original 10 surface in a line in the main scanning direction, and the directly reflected light, which is non-information light, is removed through the cylindrical lens 12 again, and the scattered light, which is information light, is illuminated by the condensing cylindrical lens. Light receiving sensor arrays 1 ₁ on both sides of the lens 12,
The light enters each of the ₁₂ sensor units from the lower transparent electrode 8 side. At this time, the illumination light to the document surface and the reflected light from the document surface respectively pass through the upper and lower two layers of cylindrical lens array bodies 14 and 15 arranged in the main scanning direction. Because they all have a generatrix in the sub-scanning direction, they have no power in that direction,
As a result, it has almost no effect on the light focusing action of the light focusing cylindrical lens 12, and the light flux from the document surface remains as scattered light in the sub-scanning direction of each light receiving sensor array 1 ₁ , 1 ₂ reaches the light receiving sensor surface. Therefore, it is possible to read the same information by arranging a plurality of sensor units in the sub-scanning direction.

Next, the optical relationship in the main scanning direction will be explained with reference to FIG. 5D. In this figure, for convenience, the lower surface of the first cylindrical lens array body 14 and the original 10 are shown.
It is shown with a slight distance from the surface. An image ₁₀₁ on the surface of the original 10 is converted into an inverted image 10 by one lens 141 in the first cylindrical lens array 14 having a magnification β=-1/a ( _a is a predetermined constant). ₂ is formed, and its inverted image 10 ₂
A same-magnification erect image ₁₀₃ is formed on the light receiving sensor surface by one lens ₁₅₁ in the second cylindrical lens array 15 having a magnification β'=-a. In this way, a line image of the entire document is formed on the light receiving sensor surface by the entire cylindrical lens group. That is, by using the two-layer cylindrical lens array bodies 14 and 15, information in the main scanning direction of the document surface is reproduced on the light receiving surface, thereby increasing the resolution. Furthermore, although the illumination light is influenced by the power of the cylindrical lens group in the main scanning direction, because of the optical relationship described above, it is possible to illuminate the document surface almost uniformly.

Furthermore, in this embodiment, the resolution is increased by the following procedure. That is, first, as shown in FIGS. 5A and 5B, the two-layer cylindrical lens array body 1 is
By inserting a light shielding plate 16 perpendicularly to the main scanning direction between 4 and 15, a reduction in resolution in the main scanning direction due to scattering of information light from the document surface is prevented. Second, the amount of light received is increased by increasing the length of each sensor unit in the light receiving sensor arrays 1 ₁ and ₁₂ in the sub-scanning direction. This is because the length in the sub-scanning direction does not affect the resolution in the main-scanning direction. However, the secondary and tertiary areas between the original surface and the light receiving sensor surface
Since the next reflected light becomes noise light, the light receiving sensor unit cannot be made unnecessarily long in the sub-scanning direction, but high-order reflected light can be prevented to some extent by providing an anti-reflection coating on the light receiving sensor surface.

In order to read the entire document, the device and the document are moved in the sub-scanning direction, but the driving means thereof is not shown in the figure.

In addition, in this embodiment, the cylindrical lens array body can be arranged in any number of layers, not just the two layers shown in the illustrated example, as long as it maintains a conjugate relationship between the document surface and the light receiving sensor surface. The pitch of the cylindrical lens does not need to depend on the pitch of the light receiving sensor unit, and even a large pitch will cause no problem. The individual sensor units in each light-receiving sensor array 1 ₁ , 1 ₂ are arranged in a staggered arrangement as shown in FIG. 4B above to improve resolution. Further, color information can be read by arranging a color filter on the light receiving surface of the light receiving sensor as shown in FIGS. 4C and 4D. The arrangement of this color filter is as follows: both light-receiving sensor arrays 1 ₁ ,
Only one of 1 _{and 2} may be used, or a stripe filter may be used as a whole.

The embodiment devices shown in FIGS. 2 and 5 were able to obtain twice the resolution by arranging the light receiving sensor arrays 1 ₁ and 1 ₂ in two rows, but this was achieved by arranging the light receiving sensor arrays in N rows. By arranging such arrays by shifting them by 1/N pitch so that there are no overlapping bits for each unit, it is possible to obtain N times the resolution.

FIG. 6 shows an example in which the color document reading embodiment described in FIG. 4D is applied to the apparatus shown in FIG. 1 ₁ , 1 ₂ , 1 ₃ are arranged, and red R, green G, and blue B filters are arranged on the light receiving surface side of each array 1 ₁ , 1 ₂ , 1 ₃ .

In this device, information light from an original passes through each color filter and is converted into color information by each light-receiving sensor array 1 ₁ , 1
Enter ₂ , 1 ₃ . Therefore, each light receiving sensor array 1
By independently driving ₁ , ₁₂ , and ₁₃ , it is possible to obtain color signals separated into three colors. Note that the arrangement positions of the filters R, G, and B do not have to be the same as those shown in the figure.
5 primary imaging point positions may be used.

FIG. 7 shows a third embodiment of the apparatus.
In this embodiment, an erect, equal-magnification imaging optical system is arranged between the light-receiving sensor and the document surface, at least in the main scanning direction, and the document surface and the surface of the light-receiving sensor array (light-receiving surface) are placed in a conjugate position. It is provided. Therefore, an image of the document surface is always formed on the light-receiving sensor array in an erect and same-size state at least in the main scanning direction. This is also one means of preventing optical crosstalk of information light. In addition, since the optical system is an erect, equal-magnification imaging optical system, even if the optical system is configured with a compound eye optical system, the document surface and the light receiving sensor surface always form one-to-one images in the main scanning direction. It maintains the relationship.

In addition, in the apparatus of this embodiment, a cylindrical body is arranged between the above-mentioned imaging optical system and the document surface, and one of the side surfaces of the cylindrical body serves as an entrance window for the illumination light to effectively take in the illumination light. By constantly pressing the document, it is possible to prevent blurring of the document image on the light receiving sensor surface during scanning and to stabilize reading accuracy.

That is, the apparatus shown in FIG. 7 includes a light source 13, a transparent cylindrical lens body 17 having a semicircular cross section, which is disposed in close contact with the document 10, and a transparent cylindrical lens body 17 which is fixed to the upper surface of the cylindrical lens body 17 and which is arranged in the main scanning direction. A one-dimensional erect equal-magnification lens group 18 in the form of an array, and a one-dimensional light-receiving sensor array 1 in multiple rows in the form of an array in the main scanning direction arranged above the lens group 18.
₁ and 1 ₂ (two columns in the illustrated example). The cylindrical lens 17, the erecting equal-magnification lens group 18, and the light receiving sensor arrays 1 ₁ and 1 ₂ are integrated with each other by a carrier (not shown).

Here, the one-dimensional erecting equal-magnification lens means a lens having erecting equal-magnification imaging performance in a predetermined one-dimensional direction. Further, since the light receiving sensor arrays 1 ₁ and 1 ₂ are the same as those used in the apparatuses of the first and second embodiments, a detailed explanation thereof will be omitted here.

FIG. 7B is a sectional view of the apparatus shown in FIG. 7A perpendicular to the main scanning direction. The original 10 is fed in the sub-scanning direction by rollers 19, 19. Further, the illumination light L from the light source 13 enters the cylindrical lens body 17 through one side surface ₁₇₁ , and is condensed by the light-condensing power of the lens side surface ₁₇₁ having a radius of curvature. A linear area parallel to the scanning direction is illuminated. And the information light scattered by the 10 sides of the original
L ₁ enters the light receiving sensor arrays 1 ₁ and 1 ₂ via the one-dimensional erecting equal-magnification lens group 18 .

Each lens of the one-dimensional erecting equal-magnification lens group 18 is connected to the document surface and the light receiving sensor array 1 in the main scanning direction.
The light receiving surfaces of the photodetector arrays ₁ , ₁ , and 2 are maintained in an erect, equal-magnification relationship, but in the sub-scanning direction, the power is required to condense the information light _L1 from the document surface 10 onto the light receiving sensor arrays ₁₁ , ₁₂ . has. This is because in the two-dimensional scanning method as in this embodiment, the light receiving sensor reads only one amount of information in the sub-scanning direction, so the erect equal-magnification relationship in the sub-scanning direction is not particularly necessary, but it increases the reading sensitivity. This is because it is desirable to have a light condensing effect.

The resolution in the sub-scanning direction is the amount of information light L ₁ that can be transmitted from a thin line on the document surface in that direction.
It depends on whether you get it. Therefore, in the cross-sectional view of FIG.
It is desirable to condense the light onto a point, and for that purpose, the linear light source 13 is focused on the cylindrical body 1 when scanning in the sub-scanning direction.
7 so that the relative position does not change, and the position of the linear light source 13 and the reading point P are set so that they are each in a conjugate relationship with respect to the refraction action of the side surface ₁₇ of the cylindrical body 17. . For example, as shown in FIG. 7C, it is assumed that the reading point P, which is the illumination position, is on the optical axis connecting the linear light source ₁₃ and the center of curvature of the side surface 171 of the cylindrical body 17, and the refractive index of the cylindrical body 17 is n,
The radius of curvature of side surface 17 ₁ is r, and the line light source 13 and side surface 1
Let the distance on the optical axis from the reading point P to the side surface ₁₇₁ be a, and the distance on the optical axis from the reading point _P to the side surface 171 be b. 17 Determine the position of the curve ₁ and the line light source 13. At this time, an image of the line light source 13 is formed in a line shape on the document surface. However, this imaging effect occurs only in the sub-scanning direction, and since the main scanning direction is illuminated with diverging light, uneven brightness on the light source does not become uneven illumination on the document surface.

Further, in the sub-scanning direction, as shown in FIG. 7B, the light-receiving sensor arrays 1 ₁ and 1 ₂ are located in a direction away from the specular reflection direction with respect to the illumination light L, and detect the information scattered light L ₁ , and detect the information scattered light L 1 . The specularly reflected light _L2 , which _is non-information light from the
Since the side surface ₁₇₂ is formed to have a curvature centered on the reading point P, _the light is again focused on the reading point P, increasing the illuminance at the reading point. In general, sides 17 ₁ and 17 ₂ need not have the same curvature.
Moreover, such a cylindrical body 17 can be easily produced by embossing plastic.

Furthermore, in this embodiment, in order to further increase the resolution in the sub-scanning direction, a slit plate 20 made of a light absorbing material is provided on the surface of the cylindrical body 17 facing the original 10, as shown in FIG. 7B. do. The slits ₂₀₁ of this slit plate 20 are parallel to the main scanning direction, and prevent reflected light from other than the reading point P from entering the light receiving sensors ₁₁ and ₁₂ .

Next, to explain reading in the main scanning direction, in the one-dimensional erecting equal-magnification lens group 18 arranged between the original 10 and the light receiving sensors 1 ₁ and 1 ₂ , each lens is aligned with the original surface in the main scanning direction. A vertical life-sized image is formed on the light receiving surfaces of the light receiving sensors 1 ₁ and 1 ₂ . Therefore, even with a compound eye lens, a one-to-one imaging relationship is always maintained between the document surface and the light-receiving sensor surface. By the way, in a reading device having such a configuration, the resolution in the main scanning direction during reading depends on the pitch size of each sensor unit a in the light receiving sensor arrays 1 ₁ and 1 ₂ . The smaller the pitch, the higher the resolution of the reading device can be obtained. Furthermore, although the sensor unit is very small, the erecting, equal-magnification imaging optical system always ensures a one-to-one correspondence between the surface of the light receiving sensor and the surface of the document, so that the light beam emitted from one point on the document does not reach the corresponding unit. Since it is possible to prevent the light from entering the sensor unit, it is possible to improve the S/N ratio.

In this way, the device shown in Figure 7 prevents a decrease in resolution by creating an erect, same-size image of the original on the light-receiving sensor surface, and also uses a transparent body with condensing/reflecting sides to effectively use illumination light. By using 17, it is possible to read a document with a high S/N ratio even with a low brightness light source. Furthermore, by pressing the document with the transparent body 17, it is possible to obtain an erect, life-size image that is always in focus, so that it can be read evenly. Furthermore, since the one-dimensional erect equal-magnification optical system 18 constituted by the compound eye optical system is a relatively short focus optical system,
This makes it easy to downsize the reading device.

In addition, in this embodiment, the one-dimensional erect equal-magnification lens group 1
Reference numeral 8 uses an optical system that does not have an imaging function in the sub-scanning direction, such as the two-layer cylindrical lens arrays 14 and 15 shown in the apparatus of FIG. Therefore, as the light-receiving sensors 1 ₁ and 1 ₂ in the apparatus of this embodiment, one-dimensional light-receiving sensors in which sensor units are arranged by the width of the document in the main scanning direction are arranged in M rows in the sub-scanning direction, and each row has, for example, a sensor shown in FIG. A color filter is installed as shown in D to read the color information, and a light receiving sensor in the M row is installed as shown in FIGS. 4B and C.
By shifting each image by 1/M pitch in the main scanning direction, M times the resolution can be obtained. In this case, if the one-dimensional erect equal-magnification lens group 18 is provided with such power that the information light is focused on the entire M rows in the sub-scanning direction, the reading sensitivity will be increased.

As described above, according to the present invention, it is possible to increase the resolution without technical difficulty with a simple and compact device configuration, and it is possible to provide a device that is highly usable for reading color information, etc. However, the color filter in the embodiment for reading color information is not limited to the surface of the light receiving sensor unit, but may be placed at a position optically equivalent to that provided on the surface of each unit.

In addition to the method of sub-scanning when reading a document by fixing the device and moving the document in a direction intersecting the main scanning direction (perpendicular or diagonal direction), it is also possible to perform sub-scanning by fixing the document and moving the device. Good too.

[Brief explanation of the drawing]

FIG. 1 is a perspective view illustrating an example of the configuration of a one-dimensional light receiving sensor array, and FIGS. 2A and 2B show a first embodiment of the device of the present invention, and FIG. Figure B is a cross-sectional view, Figure 3 is an enlarged partial perspective view showing an example of the structure of a transparent carrier with a light-shielding stopper surface arranged inside, and Figures 4A, B, C, and D are one-dimensional light receiving FIGS. 5A, B, C, and D are diagrams showing an example of arrangement of sensor units between sensor arrays and an example in which color filters are provided for reading color information. Figure A is a schematic perspective view of the device, Figure B is a side view seen from the sub-scanning direction, Figure C is an enlarged cross-sectional view, Figure D is an optical explanatory diagram in the main scanning direction, and Figure 6 is the device shown in Figure 5. FIGS. 7A, B, and C show a third embodiment of the device of the present invention, and FIG. 7A is a schematic perspective view of the device, and FIG. 7B is an end view. , C of the same figure is an optical explanatory diagram. 1, 1, 1 is a one-dimensional light receiving sensor array, 7 is a switching circuit, 10 is a document, 11 is a transparent carrier,
12 is a condensing cylindrical lens, 13 is a line light source, 14 and 15 are cylindrical lens arrays,
16 is a light shielding plate, 17 is a cylindrical body, 18 is a one-dimensional erecting equal-magnification lens group, 19 is an original feed roller, and 20 is a slit plate.

Claims (1)

[Scope of Claims] 1. Consists of a transparent carrier disposed with a first surface facing the document surface, and a plurality of light receiving sensor units each arranged in a predetermined direction, facing the first surface of the transparent carrier. at least two or more one-dimensional light-receiving sensor arrays arranged substantially parallel to each other facing a second surface of the document, the document reading device reading information on the document surface with the light-receiving sensor array through the transparent carrier. In the document reading device, each of the light-receiving sensor arrays is arranged relative to each other so that each sensor unit complements a gap between the other light-receiving sensor units. 2. The document reading device according to claim 1, wherein the one-dimensional light-receiving sensor array is a light-receiving sensor array in which at least a part of the one-dimensional light-receiving sensor array is provided with filter means for reading color information on the light-receiving surface side of each unit. Device.