JP3307978B2 - Image sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor for optically reading image information on paper and converting and inputting it into an electric signal, and more particularly, to an image sensor attached to a personal information device such as a word processor or a personal computer. The present invention relates to an image sensor suitable for a handy scanner that reads a two-dimensional image by manual scanning.

[0002]

2. Description of the Related Art FIG. 10 shows a conventional example of an image sensor used in this type of handy scanner. This image sensor includes an LED line light source 40 for illuminating a document having a length corresponding to the size of a document to be read, a refractive index distribution type rod lens array (hereinafter, referred to as a Selfoc lens array) 46 and a one-dimensional CCD 47 for image formation. It has an assembly structure attached to a position shown in the figure of an aluminum frame 41.

In such an assembling structure, a read image surface 45 arranged opposite to the lower surface of the frame 41 is
It is illuminated in a line by the LED line light source 40.
Then, the brightness (darkness or darkness of the image) of the reflected light in the linear (one-dimensional) area of a part of the two-dimensional image on the read image surface 45 is formed on the one-dimensional CCD 47 by the selfoc lens array 46. . One-dimensional CCD 47
The one-dimensional image information formed above is converted into a temporally serial electric signal having an amplitude corresponding to the brightness of the image by the electric scanning of the one-dimensional CCD 47.

The two-dimensional image information on the read image plane 45 moves the image sensor in the direction of YY 'in the figure at a speed sufficiently lower than the electric scanning speed per line of the one-dimensional CCD 47. The output signal from the one-dimensional CCD 47 is processed while referring to the output signal from the moving distance sensor in the YY ′ direction (not shown), so that the output signal is sequentially cut into one-dimensional shape, and a series of temporally serial Converted to electrical signals.

FIG. 11 shows details of the LED line light source 40. This LED line light source 40 has resin-molded small LED lamps 42, 42,... For mounting on the surface of a substrate arranged side by side on an elongated printed wiring board 43, and a cylindrical lens 44 having a light diffusion effect is provided in the light extraction direction. It is constituted by. According to such a configuration, the output light is condensed on the linear area on the read image plane 45, and illumination can be performed with as uniform illuminance as possible.

[0006]

However, the above-described image sensor has various disadvantages described below.

In such a handy scanner using an image sensor, when an image reading operation is performed, the portion of the image to be read is below the frame 41 of the image sensor. Those who go cannot see that part directly. For this reason, it is difficult to finely set the reading area, which is a drawback in improving the usability of the handy scanner.

[0008] The above image sensor is an LED.
Since the optical system is configured by combining individual elements such as the line light source 40, the self lens array 46, and the one-dimensional CCD 47, it is necessary to assemble while adjusting the positional relationship between these elements. A disadvantage is that the frame 41 having high reliability is required to stably fix the element at a predetermined position, and thus the structure is complicated and the production process is complicated, which leads to an increase in cost. is there. Further, this has been a bottleneck in reducing the size and weight of the device configuration.

Further, with respect to the line light source 40 for illuminating the read image plane used in this type of image sensor, the illuminance of the linear area on the illuminated image plane is made as uniform as possible. Is required,
In the above-described conventional example, in order to reduce the variation in the output of the individual LED lamps 42, element rank selection, drive circuit resistance adjustment, and the like are performed. For this reason, there is a disadvantage that the production process becomes complicated, and this also leads to an increase in cost.

In addition, in the line light source 40, L
The part where the ED lamp 42 is not mounted (the adjacent LE
Immediately below the gap between the D lamps 42), a reduction in the illuminance (ripple) occurs. Therefore, the light is scattered by using a milky white lens in the cylindrical lens 44 installed in front of the LED lamp 42 in the light emission direction to reduce this reduction. I'm trying. For this reason, there is a disadvantage that the efficiency of using light emitted from the light source is reduced.

Further, due to the influence of these ripples,
Even if the output per LED lamp 42 is improved, it is difficult to significantly reduce the number of mounted LEDs, and this still poses a bottleneck in cost reduction.

The present invention solves the above-mentioned problems of the prior art, and provides an image sensor that can directly view an image in a reading area during a reading operation and is particularly effective when applied to a handy scanner. The purpose is to:

Another object of the present invention is to provide a thin and simple structure which has high utilization efficiency of illumination light, does not require precise adjustment of an optical system at the time of assembling, and significantly improves the reliability of assembling. It is an object of the present invention to provide an image sensor which can be improved and further can reduce the cost significantly.

[0014]

According to the present invention, there is provided an image sensor for transmitting light emitted from a light emitting element onto an image surface to be read and illuminating the image surface to be read, and the illumination optical system. A light condensing optical system for transmitting spatial intensity distribution information of reflected light on the image plane to be read to the photoelectric conversion element, of the light irradiated through the light source, the illumination optical system including the light emitting element Is formed inside the first transparent substrate having the surface mounted thereon,
The condensing optical system is formed with a plurality of optical waveguides inside or on a surface of a second transparent substrate on which the photoelectric conversion element is mounted, and the light converging optical system is formed on a light emitting side of the first transparent substrate.
2 transparent substrate is disposed, and the first transparent substrate of the second transparent substrate
The image reading side should be opposite to
This achieves the above object.
Further, the image sensor of the present invention, the reading target image plane
Transmit the light emitted from the light emitting element upward and read the light
An illumination optical system for illuminating the target image surface, and
Of the irradiated light on the image surface to be read
Transmits the spatial intensity distribution information of the reflected light to the photoelectric conversion element
An image sensor provided with a condensing optical system,
A first transparent substrate having an illumination optical system on which the light emitting element is mounted
The light collecting optical system is formed inside the plate and the light
Inside or surface of the second transparent substrate with the electric conversion element mounted on the surface
A plurality of optical waveguides are formed on the surface, and at least a light emitting portion of the first transparent substrate and a light introducing portion to the optical waveguide of the second transparent substrate are laminated, and The transparency in the stacking direction of the first transparent substrate and the second transparent substrate is maintained, and the image to be read is placed in close contact with the second transparent substrate ,
Thereby, the above object is achieved.

[0015] In addition, the image sensor of the present invention, reading
Transmits the light emitted from the light emitting element onto the image to be captured
And an illumination optical system for illuminating the image surface to be read,
The object to be read of light emitted through the illumination optical system
Photoelectric conversion of spatial intensity distribution information of reflected light on the image plane
Image sensor with a condensing optical system for transmitting
The illumination optical system mounts the light emitting element on a surface thereof.
The first transparent substrate is formed inside the first transparent substrate.
A second transparent optical optical system having the photoelectric conversion element mounted on the surface;
Formed with multiple optical waveguides inside or on the surface of the substrate
It is, has an optical coupling element for controlling any spatial intensity distribution of light output from the illumination optical system, and optical coupling element is provided on at least one end face of the first transparent substrate
Which achieves the above objectives.
It is.

[0016] In addition, the image sensor of the present invention, reading
Transmits the light emitted from the light emitting element onto the image to be captured
And an illumination optical system for illuminating the image surface to be read,
The object to be read of light emitted through the illumination optical system
Photoelectric conversion of spatial intensity distribution information of reflected light on the image plane
Image sensor with a condensing optical system for transmitting
The illumination optical system mounts the light emitting element on a surface thereof.
The first transparent substrate is formed inside the first transparent substrate.
A second transparent optical optical system having the photoelectric conversion element mounted on the surface;
Formed with multiple optical waveguides inside or on the surface of the substrate
Is configured, the plurality of spacing pitch of the light emitting side end of the optical waveguide characterized in that it is arranged narrower than the spacing pitch of the light incident side, the objective reaches, by its
Is done. Further, the image sensor of the present invention can read
Transmitting the light emitted from the light emitting element onto the target image surface,
An illumination optical system for illuminating the image surface to be read;
The image to be read out of light emitted through a bright optical system
Converts the spatial intensity distribution information of the reflected light on the surface
Image sensor equipped with a condensing optical system that transmits light to the
Wherein the illumination optical system mounts the light emitting element on a surface.
Formed inside the first transparent substrate, and
A second transparent substrate having a photoelectric conversion element mounted on the surface thereof
Formed with multiple optical waveguides inside or on the surface of
The light-emitting element includes a light-emitting element having red, blue, and green light-emitting characteristics, and a color-compatible photoelectric conversion element as the photoelectric conversion element, and a transmission band of red, blue, and green. An optical filter having
It is characterized by having the above purpose
Achieved.

Preferably, an optical filter having a characteristic of transmitting only a wavelength band of an emission wavelength of the light emitting element is provided on the photoelectric conversion element mounting surface of the second transparent substrate. Preferably, the first transparent substrate is manufactured by integrally molding a transparent resin by a resin molding method.

[0018]

[0019]

In the image sensor of the present invention having the above structure,
Part of light emitted from a light-emitting element (light source) mounted on the surface of the first transparent substrate is introduced into the first transparent substrate, and is caused by a difference in refractive index between the atmosphere and the transparent substrate. First
The light is reflected on each surface of the transparent substrate and is confined in the substrate. Furthermore, of those lights, the light that hits the optical coupling element provided on an arbitrary surface of the first transparent substrate is reflected in a direction and intensity according to the direction and state of the surface on which the light hits. . Then, a part of the light that has propagated inside the first transparent substrate is emitted from the light emitting unit of the illumination optical system.

Part of the light emitted from the first transparent substrate to the outside directly or after passing through the second transparent substrate laminated on the first transparent substrate, for example, adheres to the back surface of the second transparent substrate. It is illuminated on the read image that is installed. Therefore, if the shape of the optical coupling element formed on a part of the surface of the first transparent substrate is spatially changed in accordance with an appropriate function, the read image plane is passed through the illumination optical system formed on the first transparent substrate. The intensity of the light emitted above is spatially arbitrary,
For example, it becomes uniform.

The image plane illumination optical system of the present invention differs from the conventional example in that it employs a system in which light emitted from a light source (LED lamp) is directly converged on an illumination spot. Light emitted from the element reaches the surface to be illuminated after being reflected many times on each surface inside the first transparent substrate.
Therefore, even when a plurality of light emitting elements are used, the light emitted from each light emitting element is spatially mixed in the substrate, and the influence of the variation in the light emission intensity between the light emitting elements affects the distribution of the light output. It is greatly improved.

With this operation, in the illumination optical system in the image sensor of the present invention, it is not necessary to correct the light intensity of each light emitting element individually for the output variation between a plurality of light emitting elements, which is conventionally required. In addition, on the surface to be illuminated, the effect of the decrease in the illuminance at the gap position between the light emitting elements can be almost neglected. In addition to this, the number of light sources can be reduced as long as the light output permits.

A part of the light radiated on the read image surface via the illumination optical system and reflected on the read image surface is provided on the second transparent substrate which is provided in close contact with the read image surface. After being incident on an optical signal introduction port array of a plurality of optical waveguides (for example, a three-dimensional optical waveguide), and subsequently propagating through the optical waveguide, a light exit port of the optical waveguide provided on an end face of the second transparent substrate The light is emitted from the row, enters a photoelectric conversion element provided in close contact with the surface of the second transparent substrate, and is converted into an electric signal.

Further, among the illumination light irradiated on the readout image plane through the illumination optical system of the first transparent substrate, most of the light not incident on the light waveguide and the second transparent substrate and the first transparent substrate Through the surface of the first transparent substrate or the second transparent substrate to the upper part of the substrate. On the other hand, external light that passes through the substrate surface from above the first transparent substrate or the second transparent substrate and enters the inside passes through the first transparent substrate and the second transparent substrate and adheres to the back surface of the second transparent substrate. After the light is reflected by the read image surface provided in the optical waveguide, a part of the light is incident on the optical waveguide from the array of light introduction ports of the optical waveguide, and most of the rest is again the first transparent substrate and the second transparent substrate. Through the surface of the transparent substrate and go upward.

As described above, according to the image sensor of the present invention, the read image surface is viewed through the first transparent substrate and the second transparent substrate from above the transparent substrate constituting the image sensor even during the image reading operation. It is possible. Furthermore, even when reading in a dark place, the reflected light on the read image surface of the illumination light emitted from the LED light source as the light emitting element leaks toward the upper part of the transparent substrate, so that the image of the reading unit can be confirmed. Become.

According to the above arrangement, the illumination optical system for reading the light from the illumination light source onto the image plane and the reading optical system for guiding the reflected light from the image plane to the photoelectric conversion element are each composed of one sheet. Integrally formed on a transparent substrate,
Further, since the optical system of the image sensor is formed by laminating them, a frame for fixing the conventional individual optical elements in a predetermined positional relationship is not required. Furthermore,
The light emitting element and the light receiving element can be arranged at predetermined positions on the substrate without precise positional adjustment between the elements. Therefore, according to the above configuration, the optical system of the image sensor can be assembled with only simple steps.

The shape of the transparent substrate in which the illumination optical system is formed can be integrally manufactured by a molding method using a resin or the like as a material. Products can be provided.

Further, an optical element having an optical wavelength transmission characteristic corresponding to the wavelength of light emitted from the light emitting element is provided on the end face of the second transparent substrate provided with the exit port array of the optical waveguide of the light condensing optical system. If a filter is provided, light that enters the photoelectric conversion element from outside the substrate other than the illumination optical system is cut, so that a reading error due to uneven illuminance of the read image can be reduced.

Further, the optical waveguide that is provided on a transparent substrate
If the pitch on the exit side of the light guide (for example, a three-dimensional optical waveguide) is made smaller than the pitch on the side of the light entrance within an allowable range of the resolution, it is possible to shorten the length of the one-dimensional light receiving sensor to be used. It can contribute to cost reduction.

[0030]

Embodiments of the present invention will be described below.

(Embodiment 1) FIGS. 1 to 7 show Embodiment 1 of the image sensor of the present invention. The image sensor according to the first embodiment is applied to, for example, a manual scanning image scanner (handy scanner) having a reading width of 11 cm.

This image sensor is formed by bonding a transparent substrate 2 made of glass smaller in size than the transparent substrate 1 made of acrylic to the back side. Specifically, a cutout groove 4 is formed over the entire length of the front surface side of the transparent substrate 1 and at a portion corresponding to a portion near the center in the width direction indicated by YY in FIG. Slope center line A of notched groove 4
-A 'and the oblique cut end face 11 of the transparent substrate 2 are vertically bonded so that the center line of the slope coincides.
In this bonding state, the surface of the oblique cut end face 11 of the transparent substrate 2 can be directly visually recognized through the cutout groove 4 of the transparent substrate 1.

The transparent substrate 1 and the transparent substrate 2 are bonded together by using an acrylic transparent adhesive (thickness: n = 1.49) whose cured refractive index is almost equal to that of the transparent substrate 1 (n = 1.49). 50 μm).

The transparent substrate 1 has, for example, a width of 12 cm and a length of 4 cm.
cm. Further, the notch groove 4 is specifically formed at an angle of 45 degrees with respect to the substrate surface and at a depth of 2 mm.
Are formed as inclined surfaces. Further, a portion corresponding to one end in the width direction on the back surface of the transparent substrate 1 is cut out flatly over a length of 1 mm from the back surface.
An end position (hereinafter referred to as a step line) 12 at the other end in the width direction of the cutout portion is located immediately below an intersection line BB ′ between the 45 ° inclined surface of the cutout groove and the surface of the transparent substrate 1. ing.

With the step line 12 as a boundary, the thickness of the substrate on the inclined surface side of the notch groove 4 is set to 3 mm, and the thickness on the vertical surface side is set to 2 mm.

In addition, inclined surfaces (hereinafter referred to as oblique cut surfaces) 9, 9 inclined at 16 degrees with respect to the YY ′ direction are provided on both end surfaces in the longitudinal direction at the other end in the width direction of the transparent substrate 1. ing. The oblique cut surfaces 9, 9 are, for example, 17 m
m.

The other end in the width direction of the transparent substrate 1 is formed on a saw-toothed surface 15, and on the surface of the saw-toothed surface 15, an optical coupling element 7 formed by sputtering an aluminum reflective film 8 is formed. As shown in FIG. 4, each of the saw-toothed surfaces 15 of the optical coupling element 7 has a tilt direction that is opposite to the longitudinal center CC ′ of the transparent substrate 1. Specifically, the inclination angle of the inclined surface is set at α = 37 degrees with respect to the XX ′ direction corresponding to the longitudinal direction of the transparent substrates 1 and 2. Further, the depth (height) h of the apex of the sawtooth of each saw-tooth surface 15 is constant at a constant pitch p = 0.
It is arranged at 8 mm.

The transparent substrate 1 having the above shape is integrally formed by an injection molding method, and each surface is a smooth surface. According to such an injection molding method,
There is an advantage that the transparent substrate 1 can be formed quickly and accurately.

Further, an antireflection film 14 is provided on the back surface of the portion where the diagonal cut surfaces 9 and 9 and the notch groove 4 are formed by a vacuum deposition method. An LED array light source unit 3 having a structure shown in FIG. 5 or FIG. 6 is attached to the outside of the oblique cut surfaces 9 of the transparent substrate 1. This installation is L
The light output surfaces of the ED array light source units 3 and 3 are brought into close contact with the oblique cut surfaces 9 and 9 respectively, and attached using a transparent epoxy adhesive.

This LED array light source unit 3 is shown in FIG.
Or, as shown in FIG. 6, eight LED chips 32,
32 and one load resistance element 33 are mounted in the light source case 31 made of a liquid crystal polymer in a rectangular parallelepiped shape in a line in the longitudinal direction. This light source case 31 is LE
The portion on which the D chips 32, 32,... Are mounted is a concave light reflection cup, and a light reflection film 35 (hereinafter also referred to as a wiring pattern number 35) serving as a wiring pattern by metal plating on the surface of the light reflection cup. ) Is formed.

The wiring pattern 35 is integrally formed on the surface of the light source case 31 from the mounting portion of the LED chips 32, 32 to the back electrode 34 formed on the back surface (back surface) of the case. I have. Therefore, if wiring is performed from the external power supply to the back electrode 34 in a state where the LED array light source unit 3 is mounted on the transparent substrate 1, it is possible to supply current to the LED chips 32, 32,. it can.

In the LED array light source unit 3, 8
, And one load resistance element 33 are all connected and connected in series. The LED chip 32 mounted on the wiring pattern 35 in the light source case 31 is sealed with a transparent epoxy resin filled in a concave portion of the light source case 31.

On the other hand, the transparent substrate 2 has a length of 12c, for example.
m, a width of 1.8 cm, and a thickness of 0.95 mm. The above-described oblique cut end face 11 is formed on one end face in the width direction of the transparent substrate 2. The angle of inclination of the oblique cut end face 11 is set to 45 degrees. The entire end surface of the transparent substrate 2 including the oblique cut end surface 11 is finished to a smooth surface by polishing.

In addition, the rear surface of the transparent substrate 2, that is, the surface on which the oblique cut end face 11 is viewed through the glass, has a width of about 3 mm from the front end of the oblique cut end face 11 to the opposite end face.
132 channel optical waveguides 6 each having a thickness of 0 μm and a depth of 30 μm
0 are formed. The pitch of these channel-type optical waveguides 6, 6,... Is different between the tip end of the oblique cut end face 11 and the end face on the opposite side, and the pitch at the tip end of the oblique cut end face 11 is 83.3 μm, Are set to 50.0 μm.

These channel type optical waveguides 6, 6,...
Is formed by depositing an Ag film in a waveguide pattern shape on the rear surface of the transparent substrate 2 and then diffusing Ag ⁺ ions into the transparent substrate 2 by a field ion exchange method.

The oblique cut end face 1 of the transparent substrate 2
As shown in FIG. 3, an optical wavelength bandpass filter 10 that transmits the emission wavelength (= 565 nm) of the LED array light source unit 3 is integrally formed on the end face opposite to 1 by vacuum-depositing a dielectric multilayer thin film. Is provided. Further, a one-dimensional CCD 5 is mounted on the end face of the transparent substrate 2 where the light wavelength band transmission filter 10 is provided.
This attachment is performed by opposing the one-dimensional CCD 5 along the row of light emission ports of the channel type optical waveguide 6 and using an epoxy-based transparent adhesive.

Next, the operation of the image sensor of the first embodiment will be described in detail. First, a current is externally supplied to the back electrode 34 of the LED array light source unit 3. Thereby, the LED chips 3 of the LED array light source unit 3
2, 32... Light having a wavelength of 565 nm is emitted, and most of the light is reflected on the LED unit mounting surface of the transparent substrate 1, that is, the antireflection film 1 provided on the oblique cut surfaces 9, 9.
4 and enters the inside of the transparent substrate 1.

As shown in FIG. 7, of the light incident on the inside of the transparent substrate 1, the critical angle θ
Light incident at an angle of incidence of r or more causes total reflection at the boundary surface, repeats reflection at the interface with almost no reflection loss, and is confined inside the transparent substrate 1.

Here, in the first embodiment, the transparent substrate 1
The refractive index n ₁ of the acrylic resin used as the material of the above is n ₁ = 1.49 with respect to the light source wavelength (= 565 nm), and the critical incident angle θr at the interface with the atmosphere is θr = 42.2.
Degree. Further, the LED array light source unit 3 used in the first embodiment has about 70% of the total amount of light radiated to the outside.
The degree is ± 48 degrees with respect to the optical axis (= 90−θr = 90−4)
2.2), the thickness of the transparent substrate 1 is about the same in the thickness direction of the transparent substrate 1 (60 mm) although it is as thin as 3 mm at the light incident portion. ~
(About 70%) of light can be confined inside the substrate.

Most of the light that enters the transparent substrate 1 from the LED array light source unit 3 and propagates inside the transparent substrate 1 is:
As shown in FIG. 3, the light is incident on the sawtooth surface 15 of the optical coupling element 7 formed on the end face of the transparent substrate 1. Since the serrated surface 15 is provided with an aluminum reflecting film, the aluminum reflecting film reflects a light amount corresponding to the reflectance (about 88%).

As shown by the arrows in FIGS. 3 and 4, the saw-toothed surface 15 is used to transmit a light beam that is vertically incident from the LED array light source unit 3 on the light incident surface (oblique cut surface 9) of the transparent substrate 1. , The groove direction of the notch groove 4 of the transparent substrate 1 (X
The reflection angle is set to a reflection angle (for example, 37 degrees with respect to the XX 'direction) necessary for the light to enter perpendicularly to the -X' direction. For this reason, most of the light propagating inside the transparent substrate 1 enters the cutout groove 4 through the optical coupling element 7 at an angle close to the vertical.

Further, as shown in FIG. 4, the saw-toothed surface 15 of the optical coupling element 7 is cut into the center of the transparent substrate 1 in the longitudinal direction according to a certain function f (x) (for example, a parabolic function). It is designed so that the reflection area of the saw-tooth surface 15 per unit length in the XX ′ direction can be increased as the depth increases, so that the X-
The light intensity distribution in the X 'direction can be made uniform.

In the structure of the first embodiment, the distance from the LED array light source unit 3 to the notch groove 4 is sufficiently longer than the distance between the LED chips 32, 32,. It has been set. Therefore, in the thickness direction of the transparent substrate 1, the light reaches the notch groove 4 after repeating a large number of total reflections.
The ripple due to the variation of the light intensity between the chips 32, 32..
Is hardly affected on the 45-degree slope. Therefore, in the first embodiment, there is no need to perform a work for uniformizing the light output using a means involving light loss such as a light diffusion lens as seen in the conventional LED line light source shown in FIG. .

Of the light incident on the 45-degree inclined surface of the cutout groove 4 of the transparent substrate 1, the critical angle θr (4
(2.2 °) or more is totally reflected on the inclined surface, and most of the light is transmitted through the portion 14 provided with the antireflection film on the rear surface of the transparent substrate 1 and the rear surface side of the transparent substrate 1 Injected to Part of the light emitted from the transparent substrate 1 is
The light enters the transparent substrate 2 attached to the rear surface of the transparent substrate 1 or directly illuminates the read image surface 13 disposed immediately below the transparent substrate 1.

Here, the refractive index n of soda glass, which is the material of the transparent substrate 2, is n = 1.52 with respect to the wavelength (= 565 nm) of the LED array light source unit 3, and its critical angle θr is 41.3. Degree. Transparent substrate 1 and transparent substrate 2
, A large part of the light emitted from the transparent substrate 1 and incident on the transparent substrate 2 passes through the transparent substrate 2 without being confined in the transparent substrate 2 and closely adheres immediately below the transparent substrate 2. The read image plane 13 placed on the display is illuminated.

The light applied to the read image surface 13 is reflected at an intensity corresponding to the reflectance (shading of the image) of the read image surface 13. A certain percentage of the light reflected by the portion of the transparent substrate 2 corresponding to the diagonally cut end surface 11 immediately below the channel-type optical waveguide 6 is reflected by the diagonally cut end surface 11 and is directly above each reflection point. The light enters the channel type optical waveguide 6.

Most of the light incident on the channel type optical waveguide 6 propagates through each of the channel type optical waveguides 6, 6,... And reaches the end face of the transparent substrate 2 on the opposite side to the oblique cut end face 11. The light enters the optical wavelength bandpass filter 10 provided on the end face. This optical wavelength band transmission filter 10
Is designed to have a narrow band whose light wavelength transmission band matches the light emission wavelength of the LED array light source unit 3. Therefore, the light transmitted through the transparent substrate 1 from above the transparent substrate 1 is read by the optical wavelength band transmission filter 10 so that
In the case of (3), most of the external light incident on the channel type optical waveguide 6 can be cut. Thereby, it is possible to reduce a reading error caused by uneven illuminance on the read image surface 13 due to the influence of external light.

The light transmitted through the light wavelength band transmission filter 10 is incident on the one-dimensional CCD 5 which is attached in close contact with the light wavelength band transmission filter 10, and is photoelectrically converted into an electric signal. Through the above operation, the density information of the image in the one-dimensional area immediately below the optical waveguide row along the oblique cut end face 11 of the transparent substrate 2 is converted into an electric signal.

In the first embodiment, the image sensor is Y
By moving in the −Y ′ direction and relating the output signal of the moving distance detection sensor (not shown) in the YY ′ direction and the output signal from the one-dimensional CCD 5, the oblique cut end face 1 of the transparent substrate 2 can be obtained.
The density information of the image of the two-dimensional area scanned by the one-dimensional area along one tip line can be converted into a series of electric signal information.

According to the image sensor of the first embodiment, since the read image surface 13 can be visually recognized from above even during the image reading operation, there is an advantage that the reading area can be finely set. Therefore, if this image sensor is applied to a handy scanner, its usability can be greatly improved. Further, since a frame for obtaining the mounting accuracy is not required, it is possible to reduce the size, weight, and cost of the device configuration. There is also an advantage that the production efficiency can be improved. Further, there is an advantage that the use efficiency of light emitted from the LED array light source unit 3 can be improved. Further, since the adverse effect of the ripple can be eliminated and the number of mounted LED chips 32 can be reduced, there is an advantage that the device configuration can be reduced in size and weight and the cost can be reduced.

(Embodiment 2) FIGS. 8 and 9 show Embodiment 2 of the image sensor of the present invention.

In the image sensor according to the second embodiment, the cutting line 12 of the transparent substrate 1 is located immediately below the notch groove 4 provided on the surface of the transparent substrate 1 on the vertical surface side, that is, at the line BB ′. It is provided along. The inclination direction of the inclined surface of the cutout groove 4 is opposite to the inclined direction of the first embodiment. Conversely, the thickness of the notch groove on the 45 ° inclined surface side is 2 mm, and the thickness on the vertical surface side is 3 mm. Further, in the second embodiment, the transparent substrate 2 is bonded to the back surface of the portion of the transparent substrate 1 where the LED array light source unit 3 is attached in the same manner as described above. Therefore, the second embodiment has a structure in which the illumination optical system of the transparent substrate 1 and the condensing optical system of the transparent substrate 2 are folded at the reading area line and stacked.

Since the present embodiment is the same as the first embodiment except for the above points, corresponding parts are denoted by the same reference numerals and detailed description thereof will be omitted.

In the second embodiment, the same effects as in the first embodiment can be obtained.

Third Embodiment Next, a third embodiment of the image sensor according to the present invention will be described. The image sensor according to the third embodiment is a color image sensor. For this reason, in the third embodiment, as the LED array light source unit, instead of the LED chip 32 of the green (565 nm) emission wavelength used in the LED array light source unit 3 of the first embodiment, red, blue and green light are used. A structure in which three LED chips each having three color light emission characteristics, that is, nine LED chips in total are used. The output light of this LED array light source unit exhibits characteristics close to white light.

In the third embodiment, a one-dimensional CCD corresponding to a color image is used as a one-dimensional photoelectric conversion element (light receiving element) mounted on the transparent substrate 1. Further, in the first and second embodiments, the optical wavelength band transmission filter 10 formed on the end face of the transparent substrate 1 is used as the optical filter. In the third embodiment, each light receiving element of the one-dimensional color CCD is used. Red, green, blue (LED of light source) formed on the surface of pixel
An optical filter having a transmission band of (equivalent to the emission wavelength of) is used. The structure of the third embodiment excluding this point is the same as that of the first embodiment.
Alternatively, the structure is the same as that of the second embodiment.

According to the configuration of the third embodiment, a color image can be read. That is, according to the third embodiment, a color image sensor can be realized.

The object to which the present invention is applied is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

[0069]

According to the image sensor of the present invention described above,
At the time of the image reading operation, the read image surface including the read scanning lines is located below the first transparent substrate and the second transparent substrate, but most of the light that has hit the first transparent substrate from above the image sensor is the first transparent substrate. The light can pass through the transparent substrate and the second transparent substrate and reach the read image surface. Most of the light that has reached the read image surface is reflected on the read image surface and then passes through the first transparent substrate and the second transparent substrate again and is emitted to the upper part of the image sensor. Can be visually recognized from above the image sensor even during the image reading operation. Therefore, when the image sensor of the present invention is applied to a handy scanner, it is possible to finely set the reading area, and there is an advantage that the usability can be remarkably improved.

Also, of the light emitted from the light emitting element mounted on the image sensor and passing through the inside of the first transparent substrate and irradiated on the read image surface near the read scan line, the light is provided on the second transparent substrate. Most of the light that does not enter the optical waveguide is transmitted through the second transparent substrate and the first transparent substrate, and is emitted to the upper part of the image sensor. Since the light illuminating the read image area can be seen from above the substrate, there is an advantage that the read image area can be confirmed even when the image sensor is used in a dark place.

Further, in the image sensor of the present invention, all of the reading optical system includes the first transparent substrate and the second transparent substrate.
Since it is integrally formed on or inside the transparent substrate, the first transparent substrate and the second
The bonding of the transparent substrate and the mounting of the light-emitting element and the photoelectric conversion element on the transparent substrate do not require precise position adjustment, and are as simple as mounting electronic components on an electric circuit board. The system can be assembled. As a result, the manufacturing efficiency can be remarkably improved, and the cost can be significantly reduced.

The optical system formed on the transparent substrate itself is formed by using a reflecting mirror having the outer shape of the transparent substrate, an optical waveguide manufactured using a chemical process, and a thin film forming process such as vapor deposition on the transparent substrate. Since it is integrally configured by the formed filter, the structure is extremely simple, the cost of each optical element is low, and at the same time,
There is an advantage that displacement between the optical elements hardly occurs and high reliability can be obtained.

Also, by adopting the transparent substrate integrated structure, each optical element is held and fixed at a predetermined position while securing a space required for forming an optical system between each optical element. Since the frame is unnecessary, there is an advantage that the size and weight of the apparatus can be significantly reduced.

Further, according to the image sensor of the fourth aspect, the pitch of the optical waveguide array forming the condensing optical system is narrower on the light exit side than on the light entrance side.
There is an advantage that the length of a linear photoelectric conversion element such as a CCD to be used can be shortened, which can greatly contribute to cost reduction.

According to the image sensor of the fifth aspect , since the optical filter having the transmission band equal to the emission wavelength of the light emitting element is provided, it is possible to prevent the occurrence of a reading error due to the bad influence of external light. There is an advantage that reliability can be greatly improved.

According to the image sensor of the sixth aspect , since a transparent substrate having a complicated shape can be integrally formed, there is an advantage that variation in product specifications can be reduced and cost can be significantly reduced.

[0077] According particularly to the image sensor of claim 7, there is an advantage that can realize an image sensor for color.

[Brief description of the drawings]

FIG. 1 is a perspective view showing Embodiment 1 of an image sensor of the present invention.

FIG. 2 is a sectional view taken along the line Y-Y 'of FIG.

FIG. 3 is a plan view showing Embodiment 1 of the image sensor of the present invention.

FIG. 4 is a detailed shape diagram showing a light coupling element portion of the image sensor according to the first embodiment.

FIG. 5 is a perspective view showing an LED array light source unit of the image sensor according to the first embodiment.

FIG. 6 is a perspective view showing another embodiment of the LED array light source unit in the image sensor according to the first embodiment.

FIG. 7 is an explanatory diagram showing a state of light introduction and propagation of light to a transparent substrate in the image sensor according to the first embodiment.

FIG. 8 is a perspective view showing Embodiment 2 of the image sensor of the present invention.

FIG. 9 is a sectional view taken along line Y-Y ′ of FIG. 8;

FIG. 10 is a sectional view showing a conventional example of an image sensor.

FIG. 11 illustrates an L used in the image sensor shown in FIG.
FIG. 3 is a perspective view showing an ED array light source unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transparent substrate (first transparent substrate) 2 transparent substrate (second transparent substrate) 3 LED array light source unit 4 cutout groove 5 one-dimensional CCD 6 channel type optical waveguide 7 optical coupling element 8 aluminum reflection film 9 oblique cut surface 10 light Wavelength band transmission filter 11 Oblique cut end face 12 Break line 13 Reading image face 14 Antireflection film 15 Sawtooth face of optical coupling element 31 Light source case 32 LED chip 33 Load resistance element 34 Back electrode 35 Wiring pattern also serving as reflecting mirror

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-58659 (JP, A) JP-A-3-142967 (JP, A) JP-A-62-1110358 (JP, A) JP-A-2- 10964 (JP, A) JP-A-2-58469 (JP, A) JP-A-60-189256 (JP, A) JP-A-57-69250 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 27/14 H04N 1/028 H04N 1/04 JICST file (JOIS)

Claims (7)

(57) [Claims] 1. An illumination optical system for transmitting light emitted from a light emitting element onto an image surface to be read and illuminating the image surface to be read, and an object to be read of light radiated through the illumination optical system. A condensing optical system for transmitting spatial intensity distribution information of reflected light on an image plane to a photoelectric conversion element, wherein the illumination optical system is provided inside a first transparent substrate on which the light emitting element is mounted. in conjunction with the formation, the focusing optical system is formed with a plurality of optical waveguides on the inside or on the surface of the second transparent substrate mounted with the photoelectric conversion elements on the surface, of the first transparent substrate The second transparent substrate is arranged on the light emitting side
And the second transparent substrate is opposed to the first transparent substrate arrangement side.
An image reading side opposite to the image reading side . 2. A light emitting element emits light onto an image surface to be read.
Transmitted light to illuminate the image surface to be read.
Illumination optical system, and the object to be read of light emitted through the illumination optical system
Photoelectric conversion of spatial intensity distribution information of reflected light on the image plane
Image sensor with a condensing optical system for transmitting
The illumination optical system is provided with a first transparent light-emitting element mounted on a surface thereof.
Formed inside the light-emitting substrate, and
The inside of the second transparent substrate having the photoelectric conversion element mounted on the surface or
Is formed with a plurality of optical waveguides on the surface, at least a light emitting portion of the first transparent substrate and a light introducing portion to the optical waveguide of the second transparent substrate are laminated, and the with transparency in the stacking direction of the first transparent substrate and the second transparent substrate is held, characterized in that the read target image in close contact with the second transparent substrate is disposed
Image sensor to be. 3. A light emitting element emits light onto an image surface to be read.
Transmitted light to illuminate the image surface to be read.
Illumination optical system, and the object to be read of light emitted through the illumination optical system
Photoelectric conversion of spatial intensity distribution information of reflected light on the image plane
Image sensor with a condensing optical system for transmitting
The illumination optical system is provided with a first transparent light-emitting element mounted on a surface thereof.
Formed inside the light-emitting substrate, and
The inside of the second transparent substrate having the photoelectric conversion element mounted on the surface or
Is formed with a plurality of optical waveguides on the surface, and has an optical coupling element for controlling the light output from the illumination optical system to an arbitrary spatial intensity distribution, wherein the optical coupling element is the first optical coupling element. Being provided on at least one end face of the transparent substrate.
Characteristic image sensor. 4. A light emitting element emits light onto an image surface to be read.
Transmitted light to illuminate the image surface to be read.
Illumination optical system, and the object to be read of light emitted through the illumination optical system
Photoelectric conversion of spatial intensity distribution information of reflected light on the image plane
Image sensor with a condensing optical system for transmitting
The illumination optical system is provided with a first transparent light-emitting element mounted on a surface thereof.
Formed inside the light-emitting substrate, and
The inside of the second transparent substrate having the photoelectric conversion element mounted on the surface or
Is formed with a plurality of optical waveguides on the surface.
Is, that it is arranged narrower than the spacing pitch of the spacing pitch is the light incident side of the light emitting side ends of the plurality of optical waveguides
Characteristic image sensor. 5. A light emitting element emits light onto an image plane to be read.
Transmitted light to illuminate the image surface to be read.
Illumination optical system, and the object to be read of light emitted through the illumination optical system
Photoelectric conversion of spatial intensity distribution information of reflected light on the image plane
Image sensor with a condensing optical system for transmitting
The illumination optical system is provided with a first transparent light-emitting element mounted on a surface thereof.
Formed inside the light-emitting substrate, and
The inside of the second transparent substrate having the photoelectric conversion element mounted on the surface or
Is formed with a plurality of optical waveguides on its surface , has light emitting elements each having a red, blue, and green light emitting characteristic as the light emitting element, and has a photoelectric conversion element corresponding to a color as the photoelectric conversion element. It has a conversion element, and red, provides an optical filter having a blue and green transmission band
An image sensor, comprising: To wherein said photoelectric conversion element mounting surface of the second transparent substrate, claims an optical filter is provided having a characteristic of transmitting only the wavelength band of the emission wavelength of the light emitting element
6. The image sensor according to any one of 1 to 5 . Wherein said claims 1 to 5 gall first transparent substrate is manufactured by integrally molding a transparent resin by resin molding
2. The image sensor according to claim 1 .