JPH1127479A - Solid-state image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-state image pickup device for photographing an object such as a photograph without inconvenience which may cause a large friction between the object and a cover of the image pickup device. SOLUTION: This device 4 is provided with a case 11, a light source 14 contained in the case 11, a board 16 on which an optical lens 15 and a solid- state image pickup element 17 are mounted, and a cover 12 covering an opening of the case 11, and a rugged surface of the cover 12 is formed. Thus, even when an object with a large surface friction coefficient such as a photograph is carried by a roller while being adhered onto the surface of the cover 12, the friction between the object and the cover 12 is reduced by the rugged surface, thus sticking of the object to the cover 12 is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a solid-state imaging device, and more particularly to a solid-state imaging device for imaging a subject while touching the same.

[0002]

2. Description of the Related Art Some image pickup apparatuses used in scanners, fax machines and the like pick up an image of a subject sent from a roller or the like while making contact with the object. As shown in FIG. 4, such a contact-type solid-state imaging device includes a contact-type imaging module 4 generally called a CIS (Contact Image Sensor) module.

[0003] The roller 3 is rotated by a drive unit 2 including a motor and a gear. The contact-type imaging module 4 captures an image of a subject (not shown) transmitted by rotation of the roller 3, and generates and outputs an image signal. The drive control of the drive unit 2, the operation control of the contact type imaging module 4, and the processing of the output image signal are performed by the signal processing circuit 1.

As shown in FIG. 5, a contact-type imaging module 4 has a housing 11 having an opening surface, and covers the opening surface.
A light-transmitting cover 12 made of glass, resin, or the like;
A light source (not shown) housed in the housing 11;
It includes an optical imaging lens and a solid-state imaging device. The roller 3 is in contact with the outer surface of the cover 12 of the contact type imaging module 4 in a state where a constant pressure is applied.

[0005] As shown in FIG.
The roller 3 and the contact type imaging module 4
Is moved in the direction of arrow B while contacting the surface of the cover 12 of the contact imaging module 4. In the contact-type imaging module 4, light is emitted from the light source, passes through the cover 12, is reflected on the surface of the subject 5, is received by the solid-state imaging device via the cover 12, and the optical imaging lens, and an image signal is generated. Output to the outside.

[0006]

However, the conventional solid-state imaging device has the following problems. The subject includes various originals such as paper, photographs, and films. When capturing an image of a subject having a relatively small coefficient of friction due to irregularities on the surface such as paper, the subject can be smoothly fed between the roller 3 and the cover of the contact-type imaging module 4, so that the image can be taken without any trouble. Can be. However, when an image of a subject having a small coefficient of friction and a large friction coefficient is taken as in a photograph, a large frictional force is generated between the subject and the cover 12. As a result, the frictional force between the cover 12 and the object exceeds the frictional force between the roller 3 and the object, and the object is sent obliquely instead of being sent straight, or the object adheres to the surface of the cover 12. There has been a phenomenon that the cover 12 is damaged due to the damage or the surface of the cover 12 is scratched.

Conventionally, there is a case in which an image of a subject having such a fear is taken after the subject is sandwiched between transparent resin films having a small surface friction coefficient. However, in this method, a resin film is interposed between the subject and the imaging device, so that there is a problem that the resolution is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a solid-state imaging device capable of imaging a subject such as a photograph in which a large frictional force easily occurs with a cover of the imaging device without any trouble. The purpose is to provide.

[0009]

A solid-state imaging device according to the present invention includes a solid-state imaging module for imaging an object while touching the object. The solid-state imaging module has an area in contact with the object on a surface of a portion in contact with the object. It is characterized in that a process of reducing the number is performed.

Since the surface of the portion of the solid-state imaging module that comes into contact with the subject is subjected to a process of reducing the area of contact with the subject, the frictional force between the subject and the subject is reduced, and the subject is attached to the solid-state imaging module. It is possible to take an image while smoothly feeding without causing any problem such as sticking.

The solid-state imaging device according to the present invention includes a roller that rotates to feed a subject, and a solid-state imaging module that takes an image of the subject that has been sent by rotating the roller while contacting the solid-state imaging device. The module is characterized in that irregularities are formed on the surface of the portion that comes into contact with the subject.

Here, the solid-state imaging module includes a housing having an opening surface, a cover covering the opening surface of the housing,
A light source housed in the housing, a lens housed in the housing, and light emitted from the light source is transmitted through the cover to irradiate a subject, and light reflected by the subject is transmitted through the cover. And receiving a light collected by the lens, comprising a solid-state imaging device housed in the housing,
Irregularities may be formed on the surface of the cover.

The unevenness may be formed on the entire outer surface of the cover, or the unevenness may be formed only on the portion that contacts the subject.

The size of the irregularities is from 10 μm to 100
It is preferably in the range of μm.

Alternatively, the unevenness may be formed such that the glossiness of the cover is in the range of 65 to 105.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration of a contact-type imaging module included in the solid-state imaging device according to the present embodiment. The imaging module 4 includes a housing 11 having an open top and a housing 1.
A light-transmitting cover 12 made of glass or resin, which covers the opening surface of the light-emitting device 1, a light source 14 housed in a housing 11, an optical imaging lens 15, and a semiconductor substrate 16 on which a solid-state imaging device 17 is mounted. It has.

Conventionally, the surface of the cover 12 has not been subjected to a process for reducing the frictional force between the cover 12 and the subject, and has been flat. Therefore, as described above, a large frictional force is generated between the cover 12 and a subject such as a photograph having almost no unevenness on the surface and a large friction coefficient, and the subject is damaged by sticking to the cover 12. And so on.

On the other hand, in the present embodiment, the cover 12
Is characterized in that a process for reducing the friction coefficient with respect to the subject is performed on the outer surface of the. Specifically, minute irregularities are formed on the surface of the cover 12 so as to reduce the contact area between the cover 12 and the subject. Due to the presence of the irregularities, the frictional force generated between the subject and the cover 12 is reduced, and the frictional force generated between the subject and the roller is prevented from exceeding the frictional force required for feeding the subject. Is done. Therefore, it is possible to prevent a phenomenon in which the subject is smoothly sent by the roller while contacting the cover surface, and the subject is stuck to the roller and is damaged or sent in an oblique direction. Further, since the image can be taken while directly contacting the cover 12 without covering the subject with a transparent resin film or the like, it is also possible to prevent the resolution from deteriorating.

The surface irregularities of the cover 12 may be formed on the entire area 21a of the outer surface of the module 13 as shown in the plan view of FIG. 2A, or as shown in FIG. A region 21b near the center along the longitudinal direction of the cover 12
May be partially formed.

As shown in FIG. 2B, when the unevenness is formed in the partial area 21b, the area having the width X which receives the pressure from the roller 3 via the subject 5 as shown in FIG. It is desirable to form it so as to include at least 31.

The formation of the irregularities on the surface of the cover 12 may be performed by any method. For example, when the cover 12 is made of glass, fine irregularities having random orientation can be formed by dissolving the surface with a solution containing hydrofluoric acid.

In general, as the size of the unevenness increases, the frictional force between the subject and the cover can be reduced, but if the size is too large, the resolution (MTF (Modulation Transfer Functio
n) value). Then, the size of the unevenness formed on the cover surface was measured and used as a solid-state imaging device. As a result, it was found that the size of the unevenness was desirably in the range of 10 μm to 100 μm.

The gloss of the cover 12 and the cover 12
Referring to FIG. 3, a result obtained by actually measuring the relationship with the resolution at the time of performing imaging by using is described. Here, the horizontal axis indicates the glossiness of the cover 12, and the cover 12 having the glossiness 135 has no irregularities on the surface. The rate decreases. The vertical axis indicates the MTF value. This MT
The F-number is used to compensate for the influence of the characteristics of the solid-state imaging device other than the cover 12, so that the glossiness 13 with no unevenness is formed.
MTF value when the cover 12 of No. 5 was used was 100 (%)
And MT when the cover 12 having the unevenness is used.
The F value is shown as a relative value (%) to 100.

As described above, when the cover 12 having a gloss of 135 with no unevenness is used, the MTF value is 100
(%), The MTF value when using the cover 12 having a gloss of 110 on which small irregularities are formed is about 95 (%), and the MTF value is about 92 (%) with the cover having a gloss of 85 because the irregularities gradually increase. ), About 85 (%) with a cover 12 having a gloss of 65,
The MTF value of the cover 12 having a gloss of 50 was about 78 (%).

The upper limit of the glossiness is set by a limit at which a phenomenon such as sticking to the surface of the cover 12 does not occur when a subject such as a photograph having a large friction coefficient is sent and imaged.
As a result of actual measurement, it was about 105. The lower limit of the glossiness is set by the limit of the MTF value practically used as a solid-state imaging device, and is set to about 65 (MTF value of about 85). Therefore, it is desirable to use the cover 12 that has been subjected to a surface treatment such that the glossiness is in the range of 65 to 105.

The above embodiment is merely an example, and does not limit the present invention. For example, in the above-described embodiment, the surface of the cover that covers the opening surface of the imaging module is subjected to processing that reduces the contact area with the subject. However, the case is not limited to the case where the envelope of the imaging module includes a housing having an open upper surface and a cover that covers the upper surface. For example, the side surface and the upper surface of the envelope may be integrally formed. Therefore, the process of reducing the contact area may be performed not only on the cover surface but also on the surface of the imaging module that contacts the subject.

Further, the surface treatment of the imaging module for reducing the contact area with the subject is not limited to unevenness.
Further, even when the unevenness is formed, the cross-sectional shape is not limited, and the convex portion may have an acute angle shape or a round shape.

[0029]

As described above, in the solid-state imaging device according to the present invention, since the surface in contact with the subject is subjected to the processing for reducing the contact area, the subject such as a photograph having a large friction coefficient can be smoothly processed. To send an image.

[Brief description of the drawings]

FIG. 1 is a front view showing a configuration of a solid-state imaging device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a region where irregularities are formed on a cover surface of the solid-state imaging device.

FIG. 3 is a graph showing a relationship between a glossiness of a cover and an MTF value.

FIG. 4 is a perspective view showing the arrangement of a contact-type imaging module, a roller, and a signal processing circuit to which the present invention can be applied.

FIG. 5 is a perspective view showing an image pickup module and rollers to which the present invention can be applied.

FIG. 6 is a front view showing a relationship between an imaging module, a roller, and a subject to which the present invention can be applied.

[Explanation of symbols]

 Reference Signs List 1 signal processing circuit 2 drive unit 3 roller 4 imaging module 5 subject 11 housing 12 cover 14 light source 15 optical imaging lens 16 substrate 17 solid-state imaging device 21a, 21b, 31 area

Claims (7)

[Claims] 1. A solid-state imaging device including a solid-state imaging module for imaging an object while touching the object, wherein the solid-state imaging module is provided with a process of reducing an area in contact with a subject on a surface of a portion in contact with the subject. A solid-state imaging device. 2. A roller that rotates to feed a subject, and a solid-state imaging module that captures an image of the subject that the roller has rotated while contacting the roller, wherein the solid-state imaging module contacts the subject. A solid-state imaging device, characterized in that irregularities are formed on the surface of the portion. 3. A solid-state imaging module, comprising: a housing having an opening; a cover covering the opening of the housing; a light source housed in the housing; and a lens housed in the housing. The light emitted from the light source passes through the cover and is applied to the subject, and the light reflected by the subject passes through the cover and receives the light collected by the lens.
3. The solid-state imaging device according to claim 1, further comprising: a solid-state imaging device housed in the housing; 4. The solid-state imaging device according to claim 3, wherein irregularities are formed on the entire outer surface of the cover. 5. The solid-state imaging device according to claim 3, wherein the outer surface of the cover has irregularities only in a portion that contacts the subject. 6. The size of the unevenness is from 10 μm to 100 μm.
The solid-state imaging device according to claim 3, wherein the distance is in a range of μm. 7. The solid-state imaging device according to claim 3, wherein the unevenness is formed so that the glossiness of the cover is in a range of 65 to 105.