JPH11146132A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain high read accuracy and to reduce the manufacture cost of an image reader. SOLUTION: In the image reader that is provided with a lighting means emitting lights onto an original face 10 linearly, a light collection means forming an image of light reflected from the original face receiving the light, and pluralities of light receiving elements 15 arranged linearly that receive the image- forming light and apply photoelectric conversion to the light so as to detect image data on the original face by use of optical input to the light receiving elements. The lighting means and the light collection means are respectively provided with a light guide means 3 and a light collection member 4 consisting of a light transmission member whose refractive index is n1 or more and placed to a common mother member 2 whose refractive index is n1, and the lighting means emits lights from one or pluralities of light emitting elements 7 via a light guide means 3 as linearly irradiated light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device for reading an image of a document as an input device of a computer, a facsimile, a copying machine, or the like.

[0002]

2. Description of the Related Art An image reading device is used as an image input device.
It has excellent operability and versatility, and is widely used in recent years in the fields of OA equipment, information equipment, and the like. In particular, in recent years, the demand for home-use facsimile machines has increased, and a small-sized and easy-to-use image reading apparatus has been demanded. Image reading devices are becoming widespread. FIG.
FIG. 1 is a cross-sectional view of a conventional contact type image reading apparatus, the outline of which will be described.

As shown in FIG. 9, a contact type image reading apparatus includes a document reading light receiving element 21 in which a plurality of sensor pixels for performing photoelectric conversion are arranged, a protection film 22, and a substrate 23 on which this is mounted. An element array 24, an LED array 25 that is a linear light source for irradiating the original, a lens array 26 that forms an image of the original 29 on the light receiving element array 24 that is a light receiving unit, and a transparent plate on which the original 29 is placed. 27 and an outer case 28 supporting these members.

The operation of the contact type image reading apparatus is as follows.
The original surface is illuminated by the LED array 25, and the diffuse reflected light on the reading line of the original surface is imaged on the light receiving element array by the lens array 26, and the original 2 having the reflected light
Each of the sensor pixels in the light receiving element array 24 converts the density information of 9, ie, the intensity of light into an electric signal, and sends out the signal as a serial or parallel signal output for each reading line. Then, the relative position between the original 29 and the sensor pixel row is moved in the direction perpendicular to the line, and the data transmission for each line is repeated, thereby converting the two-dimensional image information into a time-series electric signal.

[0005] However, the above-mentioned contact type image reading apparatus has the following problems. One is a problem with the light source. That is, to increase the reading accuracy, L
If the number of LEDs in the ED array 25 is increased and densely arranged to substantially uniform the illuminance of the surface of the document to be illuminated, the number of LEDs used is large, so that the component cost increases, and the cost increases. Is difficult to reduce.

Another problem is related to a lens array. That is, the lens array 26 has a configuration in which rod lens arrays are conventionally arranged and connected, and in order to improve reading accuracy, the rod lens is a special material in which the refractive index is distributed by a specific function. Therefore, it is difficult to reduce the cost of the image guide member including the rod lens array.

Another problem is that the light source LE
This is an assembly problem relating to the D array 25 and the lens array 26. That is, conventionally, the LED array 25, the lens array 26, and the light receiving element array 24 were separately assembled to the exterior case 8. Therefore, a dimensional error and an assembling error of these components cause a deviation between the illumination light line on the document surface and the lens array line and a deviation between the lens array line and the light receiving element array. Due to the shift of these lines, the uniformity of the light incident on the light receiving element is reduced, and the reading accuracy is reduced. Alternatively, in order to maintain high uniformity of the light incident on the light receiving element, it takes time and effort to assemble the lines with high precision, which tends to increase the manufacturing cost.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above three problems, and the present invention solves the above problems and manufactures an image reading apparatus with high reading accuracy, in particular, a contact type image reading apparatus with low manufacturing. The purpose is to provide at a cost.

[0009]

According to a first aspect of the present invention, there is provided an illuminating means for illuminating a document surface in a line, and forming an image of the reflected light from the illuminated document surface. A light condensing means, an image reading device having a plurality of light receiving elements arranged in a line for receiving the imaged light and photoelectrically converting the light, and detecting image data of the original surface by light input to the light receiving element; The illuminating means includes a light emitting element and a light guiding means for guiding light emission of the light emitting element to the document surface,
The light guide means is characterized by comprising a base member having a refractive index N1 and one or two or more light-transmitting members having a refractive index higher than N1 disposed on the base member.

According to a second aspect of the present invention as a second means for solving the above-mentioned problems, in the first means, the light condensing means is provided on a base member having a refractive index N1 and the base member,
A translucent member having a refractive index greater than 1 and having a plurality of columns formed in parallel to the width direction with the longitudinal direction of the columnar shape facing the document surface and arranged in the direction of the line; I do.

According to a third aspect of the present invention, a light transmitting member having a refractive index greater than N1 is provided on a common base member having a refractive index N1. Thus, the light guide means and the light condensing means are integrally formed.

As a fourth means for solving the above-mentioned problems, the present invention relates to the second means or the third means,
The pitch of the arrangement of the light transmitting members of the light condensing means in the line direction is equal to or smaller than the pitch of the arrangement of the light receiving elements.

According to a fifth aspect of the present invention, there is provided a light-emitting device according to any one of the second to fourth aspects, wherein each of the light-transmitting members provided on the base member in the condensing means is provided. A lens unit is provided at both or one of the input end and the light output end.

According to a sixth aspect of the present invention, there is provided the present invention, in any one of the second to fifth means, wherein the light transmitting member and the light condensing means in the light guide means of the illumination means are provided. And / or either one of the light-transmitting members is a light-transmitting member having a different refractive index depending on the location.

According to a seventh aspect of the present invention, there is provided a light-emitting device according to any one of the first to sixth means, wherein the light-transmitting member in the light guide means of the illumination means or the light-collecting means. Is characterized by being formed by filling a groove provided in the base member.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment which is one of the preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of the contact type image reading apparatus according to the present embodiment, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is a main part of the image reading apparatus shown in FIG. It is a perspective view showing a certain optical path conversion unit. Reference numeral 1 denotes an optical path conversion unit including a base member 2 having a refractive index n1 and a light transmitting member 3 for diffusion and a light transmitting member 4 for condensing provided on the base member 2. The light transmitting member 3 for diffusion and the light transmitting member 4 for condensing are both
It is made of a light-transmitting material having a refractive index n2 having a relationship of n2> n1. Convex lenses 4b1 and 4b2 are provided at the light input end and light output end of each of the columnar lenses of the light condensing light transmitting member 4, respectively.
Is provided. Reference numeral 11 denotes a transparent plate on which the document 10 is placed. The outer case 12 made of a light-shielding material holds the optical path conversion unit 1 via the spacer 13 and directly supports the transparent plate 11. A light-emitting element 7 and a light source substrate 8 described later are attached to the optical path conversion unit 1, and the light-receiving element array 9 is disposed on the inner bottom surface of the outer case 12 at a position facing the light-collecting element 4.

The base member 2 has the shape of a prism having an irregular hexagonal cross section in which two of the six sides are concave upward, and a side surface 2b which rises vertically along the longitudinal direction of the prism. Is provided with a plurality of guide grooves 5b parallel to the vertical direction, and the light-transmissive light-condensing member 4 is filled in the guide grooves 5b. A plurality of guide grooves 5a are provided on the side surface 2a that rises obliquely on the opposite side to the side surface 2b that rises perpendicularly, so as to radiate upward from below.
The plurality of guide grooves 5 are provided at the center of the lower end of
A common groove 6 is provided in common communication with a. A light emitting element 7 made of an LED is arranged inside the common groove 6, and the light transmitting element 3 is filled in the common groove 6 and the guide groove 5 a so as to cover the light emitting element 7. A light source substrate 8 holding a light emitting element 7 is attached to a portion of the lower surface of the base member 2 adjacent to the side surface 2a. The light source substrate 8 is provided with a wiring (not shown) that is electrically connected to an electrode (not shown) of the LED as the light emitting element 7. The light source substrate 8 is attached to the base member 2 by bonding or the like before filling the translucent member 3 for diffusion with the light emitting element 7 mounted.

The spacer 13 is made of a light-transmitting material having a refractive index of n1. After being joined to the side surface 2b of the base member, it is inserted into and joined to the spacer positioning recess 12a provided on the inner wall of the outer case 12. . The light receiving element array 9 includes a document reading light receiving element 16 in which a plurality of sensor pixels 15 including phototransistors for performing photoelectric conversion are arranged, a protective film 17, and a light receiving substrate 18 on which this is mounted. The light-receiving substrate 18 is inserted into a light-receiving substrate positioning recess 12ba provided on the inner bottom surface of the outer case 12, and the line of the original reading light-receiving element 16 and the arrangement line of the light-condensing light-transmitting member 4 are perpendicular to each other. It is joined and fixed at a position that matches or substantially matches the direction. Portions of the upper end surface of the base member 2 other than the guide grooves 5a and 5b and the spacer 13
A light-shielding film 14 made of paint or the like is provided on an exposed upper end portion of the light-emitting device.

The operation of the image reading apparatus of this embodiment will be described. When a driving voltage is applied from a light source driving circuit (not shown) to the electrode of the light emitting element 7 composed of an LED through the wiring provided on the light source substrate 8, the light emitting element 7 is turned on, and any one of R, G, and B is selected according to the type of the LED. Or one color light.
FIG. 4 is a diagram showing the directional characteristics of the LED as the light emitting element 7. It tends to be strong in the direction of the light emitting main surface 7a and weaker in the direction of the side surface 7b. This tendency is the same in the direction perpendicular to the plane of FIG. In the common groove 6, a very small part of the light emitted from the light emitting element 7 is transmitted through the interface between the front and back of the diffusion transparent member 3 and radiated into the air or the base member 2, but the other light is directly emitted. The light emission spreads toward the guide groove 5a substantially in accordance with the directional characteristics shown in FIG. 3 through the reflection at the front and back interfaces, and most of the light enters the guide groove 5a. The light that has entered the guide groove 5a is partially transmitted and partially reflected at the side surface of the guide groove 5a that forms the interface between the base member 2 and the light transmitting member 3 for diffusion and the front and back interfaces.

That is, at the interface between the side surface and the back side of the light transmitting member 3 for diffusion, the relative critical angle θ1 is equal to the refractive index n1.
And n2, and θ1 = sin ^-1 (n1 / n2). At the interface with the air in the table, the inherent critical angle θ0 is determined by n2, and θ0 = sin ^-1 (1 / n2). In this example, the base member 2 is made of acrylic and n1
= 1.49, the light transmitting member for diffusion 3 is an acrylic resin, and n2 = 1.53. Therefore, from the above relationship, the critical angle θ1 of the interface with the base member 2 is θ1 = sin ⁻¹ (1 .49
/1.53)=76.9°, and the critical angle θ0 of the interface with the air is θ0 = sin ⁻¹ (1 / 1.53) = 40.8 °
It is. Part of the light that has entered the light transmitting member 3 for diffusion of the guide groove 5a is emitted outside from the interface at the upper end of the light transmitting member 3 for diffusion without passing through any of the interface on the side surface and the interface on the front and back. . Other light enters the interface at least once.

At this time, when the incident angle θ (the angle with respect to the normal line of the interface) θ is smaller than the critical angle (θ1 or θ0) of the interface, a part passes and a part reflects. When the incident angle θ is equal to or larger than the critical angle, all of the light is reflected. Since the interface between the front, back, and sides of the light transmitting member 3 for diffusion is substantially in line with the incident light as shown in FIG. 2, the incident angle with respect to the interface is often close to 90 degrees, and most of the interface is mostly used. The light is incident at an angle exceeding the critical angle of 76.9 ° or 76.9 ° of the interface, and is emitted to the outside from the interface at the upper end of the light transmitting member for diffusion 3 after one or more times of reflection without passing through the interface. Is done. Each branch portion of the diffusion light-transmissive member 3 becomes wider as approaching the upper end, and the upper end portions are arranged in a line shape close to each other, so that the light emission of the light emitting element 7 is efficiently converted into a linear light flux. The light transmitting member for diffusion 3
Is ejected from the upper end surface of the.

The ratio of the density of light rays incident on each branch of the light transmitting member 3 for diffusion and the density of light rays emitted therefrom is inversely proportional to the ratio of the width of the entrance to the exit of the branch. on the other hand,
Due to the directional characteristics of the light emitting element 7, the light beam density at the entrance of each branch tends to be higher at the center branch and lower toward the ends. Therefore, for example, when the width of the incident portion of each branch is set equal, the width of the output portion is set to an appropriate size such that it is wide at the center branch and narrower toward both ends. Then, the directivity of the light emitting element 7 is corrected, the density of the light rays of the linear luminous flux emitted from the upper end surface of the light transmitting member 3 to the outside becomes uniform, and the brightness becomes uniform. Conversely, the same applies to the case where the widths of the outgoing portions of the respective branches are made equal, and the dimensions of the incident portions are narrower at the center branch, and are wider toward both ends. The effect of is obtained.

As described above, by using one light emitting element 7, it is possible to emit light composed of a linear light beam with uniform brightness from the upper end surface of the light transmitting member 3 for diffusion. The light composed of this linear light beam is reflected on the original 10 placed on the transparent plate 11.
And the diffuse reflection light on the reading line on the document surface is incident on the light-collecting light-transmitting member 4 composed of a plurality of columnar lenses arranged in the line direction on the vertically rising side surface 2b of the base member 2. I do. Here, as shown in FIG. 3, the arrangement line of the light-condensing translucent member 4 provided on the side surface 2 b of the base member 2 is parallel to the arrangement line of the diffusion translucent member 3 provided on the side surface 2 a of the base member 2. It is provided in. The irradiation line on the document surface by the irradiation of the light emitted from the light transmitting member 3 for diffusion is originally parallel to the array line of the light transmitting member 3 for diffusion.
The reading line on the document surface is parallel to the array line of the light-transmitting light-condensing member 4. Therefore, the irradiation line and the reading line on the document surface are parallel. In this example,
The width of the irradiation line is slightly wider than the width of the reading line, and the area of the reading line falls within the area of the irradiation line.

In the area of the irradiation line, as described above, illumination with uniform brightness is performed, so that the diffuse reflected light in the area of the reading line on the document surface is reflected by the light-transmitting member 4 under the uniform conditions. It is incident on the array line. That is, the density information of the original 9 in the area of the reading line is converted into light intensity under uniform conditions, and the light is incident on the arrangement line of the light-condensing light-transmitting member 4 through the convex lens 4b1.

The light incident on the arrangement line of the light-transmitting light-condensing member 4 is opposite to the light incident on each of the columnar lenses constituting the light-condensing light-transmitting member 4 without passing through a part of the side interface. Although the light is emitted to the side, most of the light is emitted through the convex lens 4b2 to the side opposite to the incidence through one or a plurality of reflections at the interface on the side by the same principle as that already described.

Light emitted from each columnar lens of the array line of the condensing light transmitting member 4 through the convex lens 4b2 enters the corresponding sensor pixel 15 of the light receiving element array 9 to form an image. In this example, the light-transmissive light-condensing member 4 is spaced apart from the original surface and the sensor pixels to some extent.
By providing b1 and b2, it is possible to focus at a position distant from the entrance end and the exit end, and to form an image on the document surface on the sensor pixel 15 without blurring.
The position of the focal point can be adjusted to an appropriate position by appropriately selecting the curvatures of the convex lenses 4b1 and 4b2. In such a lens array, the pitch of the lenses in the array direction is made smaller and is equal to or smaller than the array pitch of the sensor pixels 15 so that the resolution of the image is formed at a predetermined level determined by the array pitch of the sensor pixels 15. Up to When the pitch of the lens array is further reduced and a plurality of columnar lenses correspond to one sensor pixel 15, the resolution limit itself does not change, but the alignment of the columnar lens with respect to the sensor pixel 15 is not changed. However, even if there is some error, it is advantageous because a predetermined resolution can be ensured. In this example, as shown in FIG. 2, the columnar lenses of the light-transmitting light-condensing member 4 are configured such that the pitch in the array line direction is smaller than the array pitch of the sensor pixels 15. In this embodiment, the columnar lens is formed by filling the groove b formed in the base member 2 with a light transmitting member using a molding die or the like, so that the width and pitch in the arrangement line direction are reduced as necessary. Things can be done easily.

Each sensor pixel 15 outputs an electric signal corresponding to the brightness of the image formed by the sensor pixel 15.
As a result, each sensor pixel 15 in the light receiving element array 9 converts the density information of the document 10 having the reflected light in the area of the reading line on the document surface, that is, the intensity of the light, into an electric signal. The output is output from a signal output terminal (not shown) for each read line. Then, by moving the relative position between the document 10 and the row of the sensor pixels 15 in the direction perpendicular to the line and repeating data transmission for each line, the two-dimensional image information is converted into a time-series electric signal. The principle of the conversion of the image information into the electric signal is the same as that of the known one.

In the present embodiment, as described above, the original 10
The light / dark information of the original 10 in the area of the reading line on the surface is converted into light intensity under uniform conditions and incident on the array line of the light-condensing light-transmitting member 4, and the incident light is condensed light-transmitting light. Since the image is guided to the member 4 and forms an image on the sensor pixel with a sufficient resolution, the image information is accurately converted into an electric signal, so that the reproducibility of image data equivalent to or higher than that of the related art can be provided.

Although not shown, when the original surface and the light-transmitting light-condensing member 4 are very close to each other, the convex lens 4b1 at the light input end can be omitted, and the sensor pixel and the light-condensing light can be omitted. When the light transmitting member 4 is very close, the convex lens 4b2 at the light output end can be omitted. This is because each columnar lens of the light-transmitting light-condensing member 4 itself does not have a light-condensing action like an optical fiber, but when the gap is close to zero, blurring of image information due to light diffusion and a decrease in resolution are tolerable. This is because

In the light-transmitting light-condensing member 4 and the light-transmitting light-condensing member 3, even if a separate condensing lens such as a convex lens is not provided, the light condensing light can be changed by changing the refractive index of the light transmitting member depending on the location. Properties can be imparted. FIG. 5 is a principle view showing such a light collecting action inside the light transmitting member. 20
Is a light transmitting member corresponding to the light transmitting member 4 for condensing or the light transmitting member 3 for diffusion, 20a is a portion having a refractive index na, 20b is a portion having a refractive index nb, and the relationship of nb> na is satisfied. The interface 20d between the portions 20a and 20b is inclined such that the central portion protrudes from the light exit surface 20c. The light ray s1 incident on the interface 20d at an angle α1 to its normal line NS is refracted to become a light beam s2 forming an angle α2 larger than the α1 with respect to the normal line NS, and passes through the portion 20a and exits outside. . If the light transmitting member 20 is only the portion 20b, the light beam s1 travels in the direction of the virtual line s3. Ray s2 is a virtual ray s
It can be seen that it is refracted inward as compared to 3. As described above, the light condensing action is performed by the lens effect of the interface 20d. The partial change in the refractive index as described above can be realized by, for example, partially mixing an additive.

The light emitting portion of the light transmitting member 3 for diffusion is prevented from diffusing light in the thickness direction or the width direction by such a principle, and is efficiently placed at a required place on the document surface with high illuminance. Can be irradiated.

As described above, in this embodiment, the light transmitting member 3 for diffusion which is optical means for illuminating the original surface and the light transmitting means for condensing light which is reflected from the original surface are provided. The optical members 4 are both formed on the common base member 2, and the optical path conversion unit 1 is integrally formed. As a result, the number of parts is reduced, the labor for manufacturing and assembling the parts is reduced, and the relative positional accuracy between the light transmitting member 3 for diffusion and the light transmitting member 4 for condensing is reduced as the optical path conversion unit 1. The original line determined by the arrangement position of the diffusion translucent member 3 with respect to the reading line on the original surface determined by the arrangement position of the light condensing translucent member 4 without special adjustment at the time of assembling. Since the illumination lines on the surface can be overlapped in a correct positional relationship, the density information of the document 10 is correctly converted into the intensity of the reflected light, and
, And the image reading performance can be improved.

Next, as for the illumination means for the original surface, as described above, the conventional light emitting device using a large number of light emitting elements on the original surface by combining one light emitting element and the light transmitting member 3 for diffusion. It is possible to irradiate an illumination line having a brightness equal to or more than that of the illumination means.
Further, since the light transmitting member 3 for diffusion can be formed by filling the guide groove 5a formed by a mold or the like with a light transmitting material at the same time as the molding of the base member 2, a conventional light transmitting member using an optical fiber or the like can be formed. The manufacturing cost can be reduced as compared with the light diffusion means. For the reasons described above, the cost of the illumination means of this example can be significantly reduced as compared with the conventional one.

Next, regarding the light transmitting member 4 for condensing the light reflected from the document surface, as described above, the light transmitting member 4 is formed by the same method as the light transmitting member 3 for diffusion. It is possible to reduce the pitch of the columnar lens, which is a constituent element thereof, so that the cost can be significantly reduced as compared with the conventional condensing optical means such as a rod lens array, and the resolution of image reading can be improved. It is advantageous in improving.

An example which is another preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 6 is a perspective view illustrating a part of the configuration of the full-color contact image reading apparatus according to the present embodiment. Reference numeral 2 denotes a base member similar to that of FIG. 1, and FIG. A plurality of guide grooves 5a are provided on the side surface 2a so as to radiate upward from below, and a common groove 6 is provided in the center of the lower end of the side surface 2a and in the vicinity thereof in common with the plurality of guide grooves 5a. Have been. Inside the common groove 6, R, G, and B LEDs are arranged as light emitting elements 7 one by one, and the common groove 6 and the guide groove 5a are covered with the light emitting elements 7 so that the light transmission for diffusion is performed. The member 3 is filled. A light source substrate 8 holding a light emitting element 7 is attached to a portion of the lower surface of the base member 2 adjacent to the side surface 2a. The light source substrate 8 has R, G,
Wiring (not shown) that is electrically connected to each of the electrodes (not shown) of the B LED is provided. Other configurations are the same as those of the embodiment shown in FIG.

The operation of this embodiment will be described. When a driving voltage is sequentially applied to the R, G, and B LED electrodes of the light emitting element 7 from the light source driving circuit (not shown) through the wiring provided on the light source substrate 8 in a time-division manner, the R, G, and B LEDs are set for each color. Lights up sequentially. Irradiation lines that cover the same reading line on the original manuscript are sequentially formed for each color according to the same principle as described above, and diffused reflected light for each color is incident on the sensor pixel according to the same principle. The density information of each color of the document 10 having the reflected light in the read line area on the document surface, that is, the intensity of the light of each color, is determined by the individual sensor pixels 15 in the light receiving element array 9 in a time-division manner. The signal is sequentially converted to an electric signal, and is output as a signal output serially or in parallel from a signal output terminal (not shown) for each read line.

Then, R in the reading line,
After the output of all of G and B is completed, the relative position between the original 10 and the column of the sensor pixels 15 is moved in the vertical direction with respect to the line, and the data transmission for each line is repeated. Converts information into time-series electrical signals. The principle of the conversion of the image information into the electric signal is the same as that of the known one. In this example, the number of LEDs is three, and the number of LEDs can be reduced as a full-color contact image reading apparatus. Other advantages are the same as those of the embodiment shown in FIG.

In the above-described embodiment, the common base member 2 is provided with the guide grooves 5a and 5b, and these are filled with a light transmitting member to constitute the optical path changing unit 1. However, the present invention is not limited to this. As shown in FIG. 7, the guide grooves 5a and 5b are formed in separate base members 2 respectively, and the illuminating means 1a and the condensing means 1b are filled with a translucent member to form the illuminating means. After separately configuring the light-collecting unit 1a and the light-collecting unit 1b, the optical path conversion unit 1 can be configured by joining the illumination unit 1a and the light-collecting unit 1b. Further, even if the illuminating unit 1a is used alone as a document illuminating unit in a separate image reading apparatus, the effect of cost reduction can be obtained. The same applies to the light collecting means 1b.

In the present invention, as shown in FIG. 8, a slit 2d for positioning is provided in the common base member 2 below the light-transmitting member 4 for condensing light in the optical path conversion unit 1, and the slit 2d receives light. A configuration in which the element array substrate 18 is housed and positioned can also be applied. In this example,
Light-receiving element array substrate 18 on which diffusion light-transmitting member 3, light-collecting light-transmitting member 4, and sensor pixel 15 are mounted on the same base material.
Is provided, these positional relationships can be set with high accuracy, and assembly into a case (not shown) can be performed without adjustment, which is easy. In this example, since the sensor pixel 15 and the light-transmitting light-transmitting member 4 are close to each other, the convex lens 4b2 at the light output end can be omitted.

[0040]

As described above, according to the present invention, an image reading apparatus having excellent reading performance can be provided at low manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view illustrating a configuration of a main part of the image reading apparatus illustrated in FIG. 1;

4 is a diagram showing directivity of light emission of a light emitting element of a light source of the image reading apparatus shown in FIG.

FIG. 5 is a principle view showing a light condensing action in a light transmitting member.

FIG. 6 is a perspective view showing a configuration of a main part of an image reading apparatus according to an embodiment of the present invention.

FIG. 7 is a perspective view illustrating a configuration of a main part of an image reading apparatus according to an embodiment of the present invention.

FIG. 8 is a perspective view showing a configuration of a main part of an image reading apparatus according to an embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a configuration of a conventional image reading apparatus.

[Description of Signs] 1 Optical path conversion unit 2 Base member 3 Translucent transmissive member 4 Condensing translucent member 4b Convex lens 5 Guide groove 7 Light emitting element 10 Document 15 Sensor pixel 16 Document reading light receiving element

Claims (8)

[Claims] An illumination means for irradiating a document surface with a line;
Condensing means for forming an image of the reflected light from the irradiated document surface, a plurality of light receiving elements arranged in a line for receiving the formed light and photoelectrically converting the light, In an image reading apparatus for detecting by light input to a light receiving element, the illuminating means includes a light emitting element and light guiding means for guiding light emission of the light emitting element to the document surface, and the light guiding means has a refractive index N1. And the N provided on the base member.
An image reading apparatus comprising one or two or more translucent members having a refractive index greater than one. 2. The light-collecting means is disposed on a base member having a refractive index N1 and has a refractive index greater than N1, and a longitudinal direction of a columnar shape is directed toward the document surface. The image reading apparatus according to claim 1, further comprising a light transmitting member in which a plurality of members formed in parallel with the width direction are arranged in the direction of the line. 3. The light guide means and the light condensing means are integrally formed by disposing a light transmitting member having a refractive index higher than N1 on a common base member having a refractive index N1. The image reading device according to claim 2. 4. The arrangement pitch of the light transmitting members of the light condensing means in the line direction is equal to or smaller than the pitch of the arrangement of the light receiving elements.
The image reading device according to claim 1. 5. The light condensing means according to claim 2, wherein a lens portion is provided at one or both of a light input end and a light output end of each light transmitting member provided on the base member. 5. The image reading device according to any one of 4. 6. The light-transmitting member in the light-guiding means of the illumination means and / or the light-transmitting member in the light-collecting means are light-transmitting members having different refractive indexes depending on locations. The image reading device according to claim 2. 7. The light transmitting member of the light guiding means of the lighting means or the light transmitting member of the light condensing means is formed by filling a groove provided in the base member. The image reading device according to claim 6. 8. The image reading apparatus according to claim 1, wherein the light emitting element and the light receiving element are provided on the common base member directly or via a holding member.