JP2000312281A - Image sensor and transparent cover for the image sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly read an image by preventing a flaw resulting in deteriorated image quality from being caused on a surface of a transparent cover without causing a defect of an easily clogged original even when the transparent cover is made of a material whose surface hardness is low. SOLUTION: The image sensor I is provided with a transparent cover 1, a light source 5 that emits light to an original D placed opposite to a surface of the transparent cover 1, and a plurality of light receiving elements 6 that receive the light reflected in a linear image read object area S of the original D to output a picture signal corresponding to the light receiving quantity. A recessed groove 10 extended in a same direction as the image read object area S is formed on the surface of the transparent cover 1 so as to contain the image read object area S and a face 10a of at least one end of the recessed groove 10 in a cross direction is formed to be an inclined plane that gradually rises from a bottom of the recessed groove 10 toward a surface 1a of the transparent cover 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor used for reading an original image and a transparent cover for the image sensor.

[0002]

2. Description of the Related Art As an example of an image sensor, there is a contact image sensor, and its general structure is shown in FIG.
The image sensor B shown in the figure includes a transparent cover 91 mounted on a case 90, a light source 92 for irradiating the transparent cover 91 with light from the back surface thereof, and a plurality of imaging lenses in a main scanning direction (paper surface). (A direction orthogonal to the lens array) and a plurality of light receiving elements 94 arranged in a row in the main scanning direction. In such a contact type image sensor B, when the light emitted from the light source 92 is applied to the document D disposed on the transparent cover 91, the light is reflected by the linear image reading target area Sa of the document D. The light is focused by the lens array 93, and the image of the document D is formed on the plurality of light receiving elements 94. Then, the plurality of light receiving elements 94 output one line of image signal having an output level corresponding to the amount of received light.

The above-described image sensor B is used by being incorporated in, for example, a facsimile machine. in this case,
A platen roller 95 is located at a position facing the transparent cover 91.
The original D is transported along the surface of the transparent cover 91 in the sub-scanning direction by the platen roller 95. However, in recent years, a means for enabling the image sensor B to be used as a handy scanner is often used as shown in FIG. 10 by providing the image sensor B detachably from the main body of the facsimile apparatus. Has been reached.

As the transparent cover 91 of the image sensor B, there are a glass cover and a synthetic resin cover. The transparent cover made of glass has an advantage that the surface hardness is high and the surface is hardly scratched, but has a disadvantage that it is easily broken when subjected to a mechanical impact and its fragments are easily scattered. In particular, when the image sensor B is used as a handy scanner, the above-mentioned drawback regarding the impact resistance becomes more serious because the user may drop the image sensor B. On the other hand, a transparent cover made of a synthetic resin can reduce the cost and can hardly cause cracking due to impact. However, those made of synthetic resin have a lower surface hardness and are more easily scratched than those made of glass. For example, if the document D is transported by the platen roller 95 with dust being bitten between the original and the surface of the transparent cover 91, the surface of the transparent cover 91 may be easily damaged. Therefore, when the transparent cover is made of a synthetic resin, the quality of the read image may be degraded due to scratches on the surface.

The inventor of the present invention has proposed a means for solving such a problem, as shown in FIG. 11, in which a groove including a linear image reading target area Sa on the surface of the transparent cover 91 is provided. Forming the 96 was conceived earlier. According to such a means, in a state where the platen roller 95 is opposed to the concave groove 96, the platen roller 95 is not pressed against the bottom surface of the concave groove 96 where the image reading target area Sa is set with a large force. Therefore, even when the transparent cover 91 is made of a synthetic resin, it is possible to prevent a portion corresponding to the image reading target area S from being easily damaged.

However, experiments made by the inventor of the present application have clarified that the following problem occurs only when the concave groove 96 having a rectangular cross section is formed on the surface of the transparent cover 91. That is, if the groove 96 is too deep, the leading end of the document D is caught in the groove 96, and the document is likely to be jammed. In addition, dust easily accumulates in the concave groove 96, which causes the quality of the read image to deteriorate. On the other hand, if the groove 96 is too shallow, the groove 96 does not serve as a groove, the bottom surface of the groove 96 is easily damaged, and the quality of the read image may deteriorate. There was.

The present invention was conceived under such circumstances, and even when the transparent cover was made of a material having a low surface hardness, there was a problem that the original was easily jammed. An object of the present invention is to make it possible to perform appropriate image reading by preventing the surface of the transparent cover from being damaged without causing a deterioration in image quality without causing the surface to be damaged.

[0008]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

[0009] An image sensor provided by the first aspect of the present invention includes a transparent cover, a light source for irradiating light to a document placed opposite to the surface of the transparent cover,
An image sensor comprising: a plurality of light receiving elements that receive light reflected from a line-shaped image reading target area of the document and output an image signal corresponding to the amount of received light, wherein the transparent cover On the surface, a concave groove extending in the same direction as the image reading target area is formed so as to include the image reading target area, and at least one surface in the width direction of the concave groove extends from the bottom of the concave groove. It is characterized in that it is a slope gradually rising toward the surface of the transparent cover.

In the present invention, the transparent cover is
A configuration made of a synthetic resin can be adopted. Further, a configuration may be adopted in which a platen roller for transporting the document is arranged to face the concave groove of the transparent cover. further,
Since the whole can be detached from the portion facing the platen roller, it can be configured to be usable as a handy scanner.

In the image sensor provided by the present invention, when a document is transported along the surface of the transparent cover, even if the leading edge of the document is immersed in the concave groove of the transparent cover, the leading edge of the document is The inclined surface at one end in the width direction of the groove can appropriately guide the groove toward the outside. Therefore, even when the groove is formed relatively deep, the document can be prevented from being caught in the groove. In addition, the inclined surface also serves as a guide surface for sweeping out dust in the groove to the outside of the groove when the document is transported along the transparent cover. Even when formed deeply, it is possible to prevent dust from collecting in the concave groove.
As described above, according to the present invention, the groove can be formed relatively deeply while preventing the original from being caught in the groove or easily accumulating dust in the groove. Even when the cover is made of a synthetic resin having a low surface hardness, a portion corresponding to the image reading target area of the transparent cover can be prevented from being easily damaged, and the quality of the read image can be prevented from deteriorating. it can.

In a preferred embodiment of the present invention, the inclination angle of the inclined surface is set to 45 ° or less.

According to such a configuration, since the inclination of the inclined surface is gentle, the document is more reliably prevented from being caught in the groove, and the action of sweeping dust from the inside of the groove to the outside of the groove is also achieved. It will be further promoted. Note that if a document moving horizontally is approaching an inclined surface,
If the inclined surface is larger than 45 °, the component force in the direction perpendicular to the inclined surface becomes larger than the component force in the direction along the inclined surface in the propulsion force of the document. On the other hand, if the inclined surface is set at 45 ° or less, such a problem can be solved, and the original can be more smoothly transferred along the inclined surface.

In another preferred embodiment of the present invention, each surface at both ends in the width direction of the groove is an inclined surface that gradually rises from the bottom of the groove toward the surface of the transparent cover. I have.

According to such a configuration, it is difficult for dust to accumulate at any position on both ends in the width direction of the concave groove.
This is more preferable for preventing the image reading target area of the transparent cover from being stained.

In another preferred embodiment of the present invention, the inclination angle of each of the inclined surfaces at both ends in the width direction of the concave groove is set to 45 ° or less, and the inclined surfaces are interposed via a flat bottom surface. And the depth d of the concave groove is 25 ≦ R / d ≦ 170 (where R is
And the width L of the groove is a value that satisfies the equation of 10 ≦ L / d ≦ 100. I have.

In the present invention, if the shape and size of the concave groove are limited to the above-mentioned values, it is possible to prevent the document from being jammed,
According to the invention of the present application, favorable effects can be obtained for any of the three items of preventing dust from accumulating in the concave groove and preventing a portion corresponding to the image reading target area of the transparent cover from being damaged. Was confirmed by the experiment of the person.

In another preferred embodiment of the present invention, the respective surfaces at both ends in the width direction of the concave groove are connected to each other via a concave curved bottom surface.

According to such a configuration, the cross-sectional shape of the groove can be made smoother, and the effect of smoothing the transfer of the original and the effect of sweeping out dust from the groove can be enhanced.

[0020] In another preferred embodiment of the present invention, a case for supporting the transparent cover is provided, and the transparent cover and the case are hooked to the case. One or more sets of engaging means are provided.

According to such a configuration, the work of mounting the transparent cover on the case can be facilitated.

In another preferred embodiment of the present invention, lenses that form an image of the original on the plurality of light receiving elements by converging light reflected from the image reading target area are arranged in a row. In addition to having the lens array arranged side by side, the case has a recess for accommodating the lens array, and the transparent cover presses the lens array toward the bottom of the recess. Are integrally formed.

According to such a configuration, the lens array can be appropriately mounted in the concave portion of the case using the transparent cover, which is convenient.

A transparent cover for an image sensor provided by the second aspect of the present invention is a transparent cover for an image sensor used by being attached to an image sensor. A groove is formed, and at least one surface in the width direction of the groove is an inclined surface that gradually rises from the bottom of the groove toward the surface. Preferably, the inclination angle of the inclined surface is
The angle is set to 45 ° or less.

The transparent cover for an image sensor having such a configuration is used by aligning its concave groove with a linear image reading target area of the image sensor. Thereby, the same effect as the image sensor provided by the first aspect of the present invention can be expected.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a perspective view showing an example of a transparent cover for an image sensor according to the present invention. FIG. 2 shows FIG.
FIG. 2 is a sectional view taken along line II-II of FIG.

The transparent cover 1 of the present embodiment shown in FIGS. 1 and 2 is manufactured by resin molding using a metal mold. The overall shape is a rectangular plate extending in a certain direction. Have been. As a specific material of the transparent cover 1, PMMA (polymethyl methacrylate (methacrylic resin)) or PC having excellent transparency and mechanical strength is used.
(Polycarbonate) is preferably used. The transparent cover 1 has a concave groove 10, a plurality of engaging projections 11a and 11b, and a convex portion 12.

The concave groove 10 is formed so as to open in the front surface 1 a (the upper surface in the drawing) of the transparent cover 1.
Extend uniformly in the longitudinal direction. The plurality of surfaces defining the groove 10 include two inclined surfaces 10 a and 10 b located at both ends in the width direction of the groove 10, and these inclined surfaces 10 a and 10 b.
There is a flat bottom surface 10c located between them so as to connect a and 10b. Each of the inclined surfaces 10a and 10b extends from the bottom surface 10c to the front surface 1
It is gradually rising toward a. Specifically, the inclination angles θa and θb are both 45 ° or less, and preferably 3 ° or more and 25 ° or less. It is desired that the depth d and the width (total width) L of the concave groove 10 be within a certain range in relation to the radius of the platen roller for transporting the document, as described later. Although not shown in the drawing, two inclined surfaces 10a and 10b and a bottom surface 10
The joint portion between the transparent cover 1 and the two inclined surfaces 10a and 10b and the surface 1a of the transparent cover 1 are rounded, and the above surfaces are smoothly connected.

As will be described later, the plurality of engaging projections 11a and 11b are portions used when the transparent cover 1 is mounted on the case of the image sensor, and are provided at both side edges extending in the longitudinal direction of the transparent cover 1. They are provided at appropriate intervals. The convex portion 12 is a portion used to press a lens array of the image sensor, as described later, protrudes downward from the rear surface 1 b of the transparent cover 1, and extends in the longitudinal direction of the transparent cover 1. Each of the projection 12 and the plurality of engagement projections 11a and 11b is resin-molded integrally with the transparent cover 1.

Next, an example of the image sensor according to the present invention will be described with reference to FIGS. FIG. 3 is a sectional view showing an example of the image sensor according to the present invention. FIG. 4 is a sectional view taken along line IV-IV of FIG.

In FIG. 3, the image sensor I of this embodiment is combined with a platen roller 2 to form a so-called sheet feed type scanner. The image sensor I includes a case 3, a substrate 4, a plurality of light sources 5, a plurality of light receiving elements 6, and a lens array 7 in addition to the transparent cover 1 described above.

The case 3 has a form extending in the main scanning direction (a direction perpendicular to the plane of the paper of FIG. 3), and a slit-shaped hole penetrating in the vertical direction and extending in the longitudinal direction of the case 3. It has a part 30. A plurality of engaging recesses 31a, 31b for engaging the engaging projections 11a, 11b of the transparent cover 1 are formed at the upper opening edge of the hole 30, and the transparent cover 1 is formed by the engaging action. Is mounted on the case 3 so as to close the upper opening of the hole 30.

The substrate 4 is assembled on the bottom of the case 3 and closes the lower opening of the hole 30. The plurality of light sources 5 are, for example, LED light sources, and are mounted on the surface of the substrate 4 in a line at appropriate intervals in the main scanning direction. The hole 30 plays a role as an illumination optical path for irradiating the light emitted from the plurality of light sources 5 toward the transparent cover 1 from the back side thereof. The wall surfaces 30a and 30b of the hole 30 are made white with high light reflectivity, and the upper side of the hole 30 is formed with the concave groove 1 of the transparent cover 1 as the upper part.
The light emitted from each light source 5 is efficiently guided toward the transparent cover 1 because it has a cross-sectional shape bent so as to approach zero.

The lens array 7 focuses the light reflected from the document D supplied to the surface of the transparent cover 1 and forms an image of one line of the document D in the main scanning direction on the plurality of light receiving elements 6. For example, a plurality of SELFOC lenses capable of forming an original image at the same magnification as an erect image are held in a resin holder so as to be arranged in a row. Of course, a convex lens or another type of lens may be used instead of the selfoc lens. The lens array 7 extends in the main scanning direction by being fitted into a concave portion 32 provided in the case 3. The convex portion 12 of the transparent cover 1 is in contact with the upper surface of the lens array 7 so as to press the lens array 7 downward, thereby positioning and fixing the lens array 7.

The lens array 7 and the transparent cover 1 are aligned so that the optical axis C of the lens array 7 is located at the center of the groove 10 in the width direction. Surface 1 of transparent cover 1
A portion of the vicinity of the height a that intersects the optical axis C of the lens array 7 is the image reading target region S. Therefore, in the present embodiment, a substantially central portion in the width direction of the bottom surface 10c of the concave groove 10 is the image reading target area S. Of course, the image reading target area S extends linearly in the main scanning direction.

The plurality of light receiving elements 6 receive the light converged by the lens array 7 and output an image signal corresponding to the amount of the received light, and are arranged in the main scanning direction. It is mounted on the surface of the substrate 4 so as to be located immediately below. The periphery of the plurality of light receiving elements 6 is surrounded by a black auxiliary member 60. This is because, since the case 3 is made of a white resin, if the periphery of each light receiving element 6 is still a white wall, light passing through the lens array 7 is scattered and reflected by the white wall. This is to eliminate the possibility that the light may enter the light receiving element 6. Therefore, for example, when the case 3 is resin-molded using a black resin, the auxiliary member 60 is unnecessary.

The platen roller 2 has shafts at both ends in the longitudinal direction supported by a fixing member (not shown), and is rotatable in a fixed direction. The case 3 has a configuration in which the concave groove 10 of the transparent cover 1 faces the platen roller 2 and can be positioned and fixed at a predetermined location so as to constitute a sheet feed type scanner. However, the case 3 is configured to be able to be detached from the place as needed, and the user can hold the case 3 and make the transparent cover 1 face the original without using the platen roller 2. It is configured so that it can be used as a handy scanner capable of reading the image of the document.

Next, the operation of the image sensor I will be described.

First, when the original D is transported on the transparent cover 1 in the sub-scanning direction by using the platen roller 2, as shown in FIG.
Get inside. However, since the area downstream of the concave groove 10 in the document transport direction is the gentle slope 10a, the leading edge Da of the document D is prevented from being caught on this portion, and the document D is properly transported. can do. When the document D is transported while being in contact with the surface of the transparent cover 1, fine paper dust is generated from the document D due to the contact, and the fine powder enters the groove 10, or may be
Such paper dust may be generated in the inside. Further, dust other than paper dust may enter the groove 10. Most of the dust (not shown) in the concave groove 10 is
As shown in FIG. 6, when the original D is transported, the original D
As a result, the sheet moves to the downstream side in the document transfer direction in the concave groove 10. In this case, the inclined surface 10a functions as a guide surface for sweeping the above-mentioned dust out of the concave groove 10. Therefore, it is possible to prevent dust from accumulating in the concave groove 10, and the bottom surface 10
The transparency of c can be prevented from being impaired by dust. In particular, in the present embodiment, the inclined surface 10b of the concave groove 10 on the upstream side in the document transport direction is also a gentle inclined surface.
Since the included angle with c is increased, it is possible to make it difficult for fine dust to accumulate at the intersections between them.

In the image sensor I, as described above, it is possible to prevent the document D from being caught in the concave groove 10 and to prevent accumulation of dust.
The depth of the concave groove 10 can be made relatively deep. As described above, if the groove 10 is too shallow, the portion that comes into contact with the platen roller 2 via the document D is easily damaged as in the case where the groove 10 is not formed in the transparent cover 1. In the image sensor I, the concave groove 10 can be appropriately deepened so as to solve such a problem. More specifically, in FIG.
0, the platen roller acting on the bottom surface 10c of the groove 10 as compared with the pressing forces Fa, Fb of the platen roller 2 acting on the two shoulders (opening edges of the groove 10) 14a, 14b extending in the longitudinal direction. 2, the depth of the concave groove 10 can be set to an appropriate depth so as to reduce the pressing force Fc. In this manner, the shoulders 14a, 14a of the concave groove 10 are formed.
The document D can be accurately transported between the document and the platen roller 2. On the other hand, the bottom 1 of the groove 10
Even if there is dust between the document 0c and the document D, it is possible to easily prevent the bottom surface 10c from being damaged due to the dust. Of course, the document D can be prevented from unjustly floating from the bottom surface 10c, so that the read image can be prevented from being out of focus.

The inventor of the present application actually manufactures the image sensor I using the transparent cover 1 having the above-described structure, and repeatedly transports the original using the platen roller 2 to thereby form the concave groove 10 of the transparent cover 1. A test was performed to observe three items, namely, whether the original D was caught, the degree of dust accumulation in the concave groove 10, and the scratches generated on the bottom surface 10c of the concave groove 10. As the transparent cover 1, the concave groove 1
0 has the cross-sectional shape shown in FIG. 2, and a large number of samples having θa and θb set at various angles are used. Transparent cover 1
, Two types of materials, PMMA and PC, were used. A4 size PPC paper (trade name: TKRA4, sold by Canon Inc.) was used as the document D, and the number of documents transferred was 2,000 in each case. The radius of the platen roller 2 is 2.5 mm to several tens mm.
The pressing force of the platen roller 2 against the transparent cover 1 was set to a value within a range in which the document D did not slip. The material of the outer peripheral portion of the platen roller 2 was silicone, and its hardness was about 40 °.

As a result of the above test, when each of θa and θb is 45 ° or less, especially when the angle is between 3 ° and 25 °, the document D is less likely to be caught and dust is less likely to accumulate in the concave groove 10. confirmed. And θa, θ
b is 45 ° or less, and if the radius of the platen roller 2 is R, the depth d of the groove 10 is 25
When the width L of the concave groove 10 is set to a value satisfying the expression of 10 ≦ L / d ≦ 100 while the value satisfying the expression of ≦ R / d ≦ 170, the result satisfying the above three items is obtained. Obtained. When the value of R / d is less than 25, or L / d
Is less than 10, the groove 10 is relatively too deep, so that dust easily accumulates in the groove 10, and the frequency of the document D getting stuck in the groove 10 is high. became. Conversely, if the value of R / d exceeds 170,
Alternatively, when the value of L / d exceeds 100, the groove 10 is relatively too shallow, and the bottom surface 1 of the groove 10
The possibility of occurrence of a scratch at 0c was increased. The same result was obtained when the transparent cover 1 was made of either PMMA or PC.

FIGS. 7 and 8 are cross-sectional views of main parts showing other examples of the transparent cover for an image sensor according to the present invention.

In the configuration shown in FIG.
The inclined surfaces 10d and 10e at both ends in the width direction of the concave groove 10A are
They are connected to each other via a concave bottom surface 10f located between them, and the entire surface defining the concave groove 10A is a smooth concave curved surface. According to such a configuration,
Since the entire surface defining the concave groove 10A is smoothly connected, it is possible to appropriately prevent the document D from being caught and dust from easily accumulating in the concave groove 10A. Also, two places 2 on the outer periphery of the platen roller 2
When a and 2b are brought into contact with shoulders 14a and 14b of groove 10A, distance s1 between tip 2c of the outer periphery of platen roller 2 and bottom 10f of groove 10A can be relatively large. Becomes Therefore, for example, when the outer peripheral portion of the platen roller 2 is made of a considerably soft member, the platen roller 2 is connected to the shoulder 1 of the concave groove 10A.
When the platen rollers 4a and 14b are strongly pressed against each other, it is possible to secure an appropriate gap between the tip end portion 2c of the platen roller 2 and the bottom surface 10f, and it is possible to prevent the bottom surface 10f from being easily damaged. As described above, in the present invention, the bottom surface connecting the inclined surfaces of the concave grooves 10A and the whole or a part of the inclined surfaces may be formed in a curved shape.

In the configuration shown in FIG.
Only the surface 10a at one end in the width direction of the groove 10B is inclined, and the surface 10g at the other end in the width direction of the groove 10B.
Is a non-inclined surface that rises substantially perpendicularly from the bottom surface 10h. Thus, in the present invention,
Of the two ends in the width direction of the concave groove, only one surface may be configured as an inclined surface. Even in such a configuration,
If the inclined surface 10a is disposed downstream of the non-inclined surface 10g in the transport direction of the document D, the leading end of the document D is
Can be hardly caught,
The dust in the groove 10B is removed by using the inclined surface 10a.
B can be smoothly swept out of B. However,
In the above structure, dust may be collected at a portion Na where the non-inclined surface 10a and the bottom surface 10h intersect (however, the portion where the dust is collected and the image reading target area S
The dust does not immediately deteriorate the transparency of the image reading target area S because it is separated from the target groove S). Preferably, the surfaces at both ends in the width direction of the concave groove are preferably inclined surfaces.

The specific configuration of each part of the image sensor and the transparent cover for the image sensor according to the present invention is not limited to the above-described embodiment, and various design changes can be made. For example, in the image sensor according to the present invention, a light source (for example, a cold cathode tube) other than the LED light source may be used as the light source.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a transparent cover for an image sensor according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view showing an example of an image sensor according to the present invention.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a sectional view of a main part showing a document transfer state.

FIG. 6 is a cross-sectional view of a main part showing a document transfer state.

FIG. 7 is a sectional view of a main part showing another example of the transparent cover for an image sensor according to the present invention.

FIG. 8 is a sectional view of a main part showing another example of the transparent cover for an image sensor according to the present invention.

FIG. 9 is a cross-sectional view illustrating an example of a conventional image sensor.

FIG. 10 is a cross-sectional view showing a state in which a conventional image sensor is used as a handy scanner.

FIG. 11 is a cross-sectional view of an essential part showing an example of a structure in which a concave groove is formed in a transparent cover of an image sensor.

[Explanation of symbols]

 I Image sensor S Image reading target area D Document 1 Transparent cover 1a Surface (of transparent cover) 2 Platen roller 3 Case 5 Light source 6 Light receiving element 7 Lens array 10, 10A, 10B Grooves 10a, 10b Inclined surface 10c Bottom surface 10d, 10e Inclined surface 10f, 10h Bottom surface 11a, 11b Engagement projection 12 Convex portion 31a, 31b Engagement concave portion 32 Recess

Claims (12)

[Claims] 1. A transparent cover, a light source for irradiating light to an original placed opposite to the surface of the transparent cover, and a light reflected from a linear image reading target area of the original by receiving the light. An image sensor, comprising: a plurality of light receiving elements that output an image signal corresponding to the amount of received light, wherein the surface of the transparent cover includes the image reading target region and is the same as the image reading target region. In the width direction, and at least one surface in the width direction of the groove is an inclined surface that gradually rises from the bottom of the groove toward the surface of the transparent cover. Features an image sensor. 2. The transparent cover is made of a synthetic resin.
The image sensor according to claim 1. 3. The image sensor according to claim 1, wherein a platen roller for transporting the document is disposed to face the concave groove of the transparent cover. 4. The image sensor according to claim 3, wherein the whole is configured to be detachable from a portion facing the platen roller, so that the image sensor can be used as a handy scanner. 5. The image sensor according to claim 1, wherein the inclination angle of the inclined surface is set to 45 ° or less. 6. The surface according to claim 1, wherein each surface at both ends in the width direction of the groove is an inclined surface that gradually rises from the bottom of the groove toward the surface of the transparent cover. An image sensor according to claim 1. 7. The inclination angle of each inclined surface at both ends in the width direction of the concave groove is set to 45 ° or less, and the inclined surfaces are connected to each other via a flat bottom surface. The depth d of the groove is 25 ≦ R / d ≦ 170 (however,
R is the radius of the platen roller disposed opposite to the transparent cover), and the width L of the concave groove is a value satisfying the expression of 10 ≦ L / d ≦ 100. The image sensor according to claim 6, wherein 8. The image sensor according to claim 1, wherein the respective surfaces at both ends in the width direction of the concave groove are connected to each other via a concave curved bottom surface. 9. A case for supporting the transparent cover, and the transparent cover and the case are provided with a case for hooking the transparent cover to the case.
A set or sets of engagement means are provided.
9. The image sensor according to any one of claims 1 to 8. 10. A lens array having lenses arranged in a row, the lenses for focusing light reflected from the image reading target area to form an image of the document on the plurality of light receiving elements. A concave portion for accommodating the lens array is formed in the case, and a convex portion for pressing the lens array toward the bottom of the concave portion is integrally formed in the transparent cover. An image sensor according to claim 9. 11. A transparent cover for an image sensor used by being mounted on an image sensor, wherein a concave groove extending in a predetermined direction is formed on a surface of the transparent cover, and at least one end in the width direction of the concave groove. A transparent cover for an image sensor, characterized in that the surface is a slope gradually rising from the bottom of the groove toward the surface. 12. The transparent cover for an image sensor according to claim 11, wherein an inclination angle of the inclined surface is 45 ° or less.