JPH11196220A - Sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a picture of high resolution by providing an envelope holding a light transmission means so that reflected light generated from transmitted light miss a photosensitive element group so as to prevent the reading of a ghost not existing in a read picture. SOLUTION: CCD 3 mounting the photosensitive element group 2 is housed within the envelope 1 consisting of ceramic and a slide glass 6 held to tilt main surfaces 4 and 5 is held at the envelope 1. Though picture light transmitted through the glass 6 is reflected by CCD 3 and reaches the main surfaces 4 and 5 of the glass 6 to be reflected again, reflected light shown by A' and A" reach positions missing the group 2 as the glass 6 (the main surfaces 4 and 5) are tilted with respect to an optical axis. Consequently, a sensor never reads a picture formed by reflected light reflected from the glass 6, namely a ghost picture, but reads a picture of high picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sensor, and more particularly, to a sensor using a CCD for transferring image signals.

[0002]

2. Description of the Related Art A CCD (Charge Coupled Device) is
Electric charges are transferred by successively forming potential wells in a semiconductor. CCD line sensors using this principle have been widely used in digital copying machines, OCRs, scanners, and the like.

In general, a line sensor equipped with a CCD is
Generally, as shown in FIG. 5, an aluminum film 10 is coated on one end of a group of photosensitive elements 2 arranged on a line as shown in FIG. The CCD is made of a ceramic or the like so as to avoid the influence of an atmosphere in which dust is generated, as shown in FIG. 6 showing a cross section of the line sensor. It is hermetically sealed by the envelope 1 and the slide glass 6, and is arranged in a space filled with an inert gas.

When an image of an original or the like through a lens or the like is transmitted through a slide glass and formed on a photosensitive element group, a part of the transmitted light is reflected by the aluminum film and the slide glass, and the photosensitive element group It reenters the top. However, in digital copiers, OCRs and scanners that deal only with black-and-white images, there are only binary values of a black signal and a white signal, so that a part of the transmitted light may re-enter the photosensitive element group. However, it was possible to eliminate such noise.

[0005]

However, in recent years, digital copiers, OCRs, scanners, and the like have come to read not only binary images of black and white but also halftones. In the digital copying machine, the OCR, the scanner, and the like, an image (ghost) originally not existing in the read image due to noise generated when a part of the transmitted light re-enters the photosensitive element group. Has been read, and a high-resolution image cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a sensor capable of preventing reading of an image (ghost) which does not exist in a read image and obtaining a high-resolution image. Aim.

[0007]

The sensor according to the present invention comprises:
C provided with a photosensitive element group that generates charges by photoelectric conversion
A CD, a light transmitting means for transmitting light to the CCD, and an outer housing for storing the CCD and holding the light transmitting means so that reflected light generated from the transmitted light is deviated from the photosensitive element group. And a container.

According to the sensor of the present invention, the light transmitting means for transmitting light to the CCD provided with the photosensitive element group which generates electric charges by photoelectric conversion is provided by the reflected light generated from the light transmitted through the light transmitting means. So that C deviates from the photosensitive element group.
Since the reflected light can be prevented from being incident on the photosensitive element group by holding the CD in the envelope in which the CD is stored, an image (ghost) that does not originally exist in the read image can be prevented. Reading can be prevented, and an image with high resolution can be obtained.

In addition, a sensor according to the present invention includes a CCD provided with a photosensitive element group that generates electric charges by photoelectric conversion, a substrate having a surface through which light is transmitted to the CCD, a CCD storing the CCD, and An envelope that holds the substrate so that the surface is inclined with respect to the photosensitive element group.

According to the sensor of the present invention, a substrate having a surface through which light is transmitted to a CCD provided with a group of photosensitive elements which generate electric charges by photoelectric conversion is inclined with respect to the group of photosensitive elements. By holding the CCD in the envelope in which the CCD is stored, it is possible to prevent the reflected light from being incident on the photosensitive element group. ) Can be prevented, and a high-resolution image can be obtained.

Further, in the sensor according to the present invention, there is provided a CC having a photosensitive element group for generating charges by photoelectric conversion on a first surface.
D, a substrate having a second surface through which light is transmitted to the CCD, and a substrate storing the CCD and being perpendicular to a normal vector of the first surface and included in the first surface. The length of the shortest straight line is t, the distance between each of the photosensitive elements and the second surface is L, and the angle between the first and second surfaces is θ (0 <θ <180 °). When θ> tan
^-1 (t / L), and an envelope holding the substrate.

According to the sensor of the present invention, the CCD having the photosensitive element group on the first surface which generates electric charges by photoelectric conversion is provided.
A substrate having a second surface that transmits light to the first substrate.
T, the length of the shortest straight line included in the first surface and the distance between each photosensitive element and the second surface is L, and the distance between the first surface and the second surface is L. Assuming that the angle between the second surface and the second surface is θ, θ> tan ⁻¹ (t / L) is satisfied.
By holding the CCD in the envelope where it is stored,
Since it is possible to prevent the reflected light from being incident on the photosensitive element group, it is possible to prevent an image (ghost) originally not existing in the read image from being read and obtain an image with high resolution. Become.

In the present invention, as an element constituting the photosensitive element group provided in the CCD, for example, a MOS capacitor or a photodiode using a polycrystalline silicon electrode can be applied. The area, shape, number of elements, and the like may be appropriately selected depending on the purpose. For example, in a line sensor applied to a facsimile or the like that reads a two-dimensional image, the photosensitive portion of the photosensitive element can be constituted by a photodiode and a channel stopper. The portion is provided with a light-shielded black dummy bit.

The light transmitting means is not particularly limited as long as it has a structure capable of transmitting light to the photosensitive element group provided in the CCD. For example, the light transmitting means is constituted by a curved surface or a large number of surfaces. It is also possible to use acrylic, glass, or the like having a light transmitting surface. However, usually, the image light reaches the photosensitive element group through a lens through the light transmitting means so as to form an image on the photosensitive element group via a lens. Therefore, as the light transmitting means, for example, a glass slide or the like is used. It is desirable to apply a substrate having a plane through which light passes. In the case where the light transmitting means made of acrylic or glass having the light transmitting surface is used, there arises a problem that the light transmitting means acts as a prism.
The arrangement of the light transmitting means with respect to the CD must be carefully adjusted.

Further, the envelope for storing the CCD can be made of, for example, ceramics or the like. In holding the light transmitting means, in order to protect the CCD from dust, etc., the envelope is used together with the light transmitting means. It is desirable to provide a structure in which a closed space is formed and a CCD can be disposed in the space. Here, the fact that the envelope holds the light transmitting means means that the envelope and the light transmitting means are configured as separate bodies, and not only when these are combined, but also that a part of the envelope is more than the light transmitting means. This is a concept that includes the case where it is configured.

Here, a mode of holding the light transmitting means in the envelope will be described. As described above, the image light reaches the CCD through the light transmitting means, but a part of the light that has reached the CCD and is reflected is reflected by the light transmitting means. Therefore, the light transmitting means is held by the envelope based on the optical properties of the light transmitting means so that the light reflected by the light transmitting means does not reach the photosensitive element group provided in the CCD. I just need. For example, when a substrate having a plane through which light passes, such as a slide glass, is applied as a light transmitting unit, and a photosensitive element group is disposed on a certain surface, light reflected by the light transmitting unit is generated. The substrate, which is a light transmitting means, is held in the envelope so that the surface is inclined with respect to the photosensitive element group. At this time, the surface of the substrate, which is perpendicular to the normal vector of the surface on which the photosensitive element group is disposed, and the axis of the longest straight line included in the surface, which generates the reflected light in the light transmitting unit, is inclined. It may be held in an envelope as in
Further, the surface of the light transmitting unit that generates the reflected light is inclined so as to be inclined with respect to the axis of the shortest straight line that is perpendicular to the normal vector of the surface on which the photosensitive element group is provided and that is included in the surface. It may be held in a container. Specifically, on a rectangular surface, when the direction in which the photosensitive elements are arranged along the sides constituting the surface is the longitudinal direction, and the direction perpendicular to the longitudinal direction on the surface is the lateral direction, CCD May be inclined at a cross section (transverse cross section) obtained by cutting the light transmission means at a plane perpendicular to the longitudinal direction.
In a section (longitudinal section) when D is cut along a plane perpendicular to the lateral direction, the surface of the light transmitting unit that generates reflected light may be inclined. However, when the surface of the light transmitting unit that generates the reflected light in the cross section is inclined, the reflected light is inclined as compared with the case where the surface of the light transmitting unit that generates the reflected light is inclined in the vertical cross section. The inclination of the generated surface can be reduced, and the sensor can be configured more compactly.

In particular, when the surface for generating the reflected light in the light transmitting means is inclined in the cross section,
The length of the shortest straight line that is perpendicular to the normal vector of the surface on which the photosensitive element group is provided and is the shortest straight line included in the surface is t, and the distance between each photosensitive element and the surface that generates reflected light in the light transmitting means. When L is an angle formed by these surfaces and θ (0 <θ <180 °), if the substrate is held by the envelope so that θ> tan ⁻¹ (t / L) is satisfied, the CCD It is possible to reliably prevent the reflected light reflected by the light transmitting means from reaching the provided photosensitive element group.

When a light transmitting means made of acrylic or glass having a light transmitting surface composed of a curved surface or a large number of surfaces is used, the light transmitting means is used based on the optical properties of the light transmitting means. The mode of holding the light transmitting means in the envelope is appropriately optimized so that the light reflected by the means does not reach the photosensitive element group provided in the CCD. When a space enclosed by the envelope and the light transmitting means is formed and a CCD is provided in the space, the space may be filled with an inert gas such as high-purity nitrogen or argon. .

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals, and detailed description will be omitted. In addition, the present invention is not limited to the present embodiment unless departing from the gist thereof.

FIG. 1 is a diagram showing a sensor according to the present embodiment, and is a top view (FIG. 1 (a)) and a cross-sectional view (FIG. 1 (b)), respectively, as viewed from the photosensitive element group side. And a longitudinal sectional view (FIG. 1 (c)).

As shown in FIG. 1, in the sensor according to the present embodiment, a CCD 3 on which a photosensitive element group 2 is mounted is stored in an envelope 1 made of ceramics. A slide glass 6 held so that the main surfaces 4 and 5 are inclined is held. The space in which the CCD is stored is sealed by the envelope 1 and the slide glass 6, and the space is filled with high-purity nitrogen gas. Note that the CCD 3 is electrically connected to the pin group 7 by a bonding wire (not shown).

Here, a mode of holding the slide glass 6 with respect to the envelope 1 will be described with reference to FIG. 2 showing a cross section taken along a line AB in FIG.

As shown in FIG. 2, the slide glass 6
Is the width of the photosensitive element group 2 with respect to the envelope 1, the distance L between the photosensitive element group 2 and the main surface of the slide glass 6 is L,
When the angle between the mounting surface of the CCD 3 and the slide glass 6 in the above is θ (0 <θ <180 °), it is held so as to satisfy θ> tan ⁻¹ (t / L). Is processed so that the slide glass 6 (main surfaces 4 and 5) can be held in an inclined state.

In the sensor according to the present embodiment, the image light transmitted through the slide glass 6 is reflected by the CCD 3, reaches the main surfaces 4 and 5 of the slide glass 6, and is reflected again. Since the slide glass 6 (main surfaces 4 and 5) is inclined with respect to the optical axis of the light A transmitted through the optical path I, the slide glass 6 does not reach the photosensitive element group 2 of the CCD 3. That is, in FIG. 2, the reflected light indicated by A ′ and A ″ ″ reaches a position deviated from the photosensitive element group 2. Therefore, in the above sensor, an image with high image quality could be read without reading an image due to the light reflected by the slide glass 6, that is, a ghost image.

When an image is read by the sensor, the original 8, the lens 9, the slide glass 6, and the photosensitive element group are arranged so as to maintain the mutual relationship as shown in FIG. , An unillustrated mirror, an optical filter, an aperture, and the like can be provided.

On the other hand, for comparison, when an image was read from an original using a sensor having the same configuration as that of the above sensor except that the main surface of the slide glass was parallel to the photosensitive element group 2, a ghost image was obtained. The image was read, and a high-quality image could not be obtained.

That is, as shown in FIG. 4, in the sensor, the light B transmitted through the optical path II reflects a part of the light on the main surface 5 (light B ') and the photosensitive element group 2
To reach. At this time, most of the light B is in the photosensitive element group 2
Is partially reflected as light B ″, is reflected again by the main surfaces 4 and 5 of the slide glass 6, and is reflected by the photosensitive element group 2 as light B ″ ″ and light B ″ ″. The points p and q are reached. At this time, the light C (here, parallel to the light B) transmitted through the optical path III overlaps with the light B ″ ′ at the point p, but the light B ′ ″ should originally reach the point p. Since the light is not light, a ghost image is formed by light read by the light. This phenomenon occurs not only at the p point but also at any area including the q point, and it is impossible to obtain a high quality image.

Thus, in the sensor according to the present embodiment, an image (ghost) that does not exist in the read image
This makes it possible to prevent image reading and obtain a high-resolution image. Further, since the sensor according to the present embodiment can hold the main surface of a general slide glass at an angle with respect to the envelope, the production efficiency does not decrease, and a rise in the production cost is suppressed. I was able to.

Note that instead of tilting the main surface of the slide glass, the same effect as in the present embodiment can be obtained by tilting the photosensitive element group mounted on the CCD. Since the amount of light to be read decreases (cos θ is lost based on the above θ), the reading sensitivity decreases. On the other hand, when the slide glass is tilted as in the present embodiment, the photosensitive element group can be arranged perpendicular to the optical axis, so that it goes without saying that the image quality does not decrease due to the decrease in the amount of light. .

[0030]

As described above in detail, according to the sensor according to the present invention, the light transmitting means for transmitting light to the CCD provided with the photosensitive element group which generates electric charges by photoelectric conversion is provided by the light transmitting means. The reflected light generated by the light transmitted through the means is held in the envelope in which the CCD is stored so that the reflected light is deviated from the photosensitive element group, so that the reflected light can be prevented from entering the photosensitive element group. Therefore, it is possible to provide a sensor capable of preventing reading of an image (ghost) that did not originally exist in the read image and obtaining an image with high resolution.

According to the sensor according to the present invention, the CCD provided with the photosensitive element group that generates electric charges by photoelectric conversion is provided.
A substrate having a surface through which light is transmitted with respect to the photosensitive element group is held in an envelope in which the CCD is stored so that the surface is inclined with respect to the photosensitive element group. Since the incidence can be prevented, it is possible to provide a sensor capable of preventing reading of an image (ghost) originally not existing in the read image and obtaining an image with high resolution.

Further, according to the sensor of the present invention, a substrate having a second surface through which light is transmitted to a CCD having a photosensitive element group that generates electric charges by photoelectric conversion on the first surface is provided. The length of the shortest straight line perpendicular to the normal vector of the first surface and included in the first surface is t, the distance between each photosensitive element and the second surface is L, and the distance between the first surface and the second surface is L. Assuming that the angle between the second surface and the second surface is θ, the CCD is held in an envelope in which the CCD is stored so that θ> tan ⁻¹ (t / L) is satisfied. Since it is possible to prevent the reflected light from entering, it is possible to provide a sensor capable of preventing reading of an image (ghost) that did not originally exist in the read image and obtaining a high-resolution image. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a sensor.

FIG. 2 is a diagram showing a cross section cut along the line AB in FIG.

FIG. 3 is a diagram showing a mutual relationship regarding the arrangement of a document 8, a lens 9, a slide glass 6, and a photosensitive element group.

FIG. 4 is a diagram illustrating formation of a ghost image.

FIG. 5 is a diagram showing the vicinity of a photosensitive element group in the line sensor.

FIG. 6 is a diagram showing an arrangement of CCDs.

[Explanation of symbols]

1 ... envelope 2 ... photosensitive element group 3 ... CCD
4, 5: Main surface 6: Slide glass 7: Pin group 8: Original 9: Lens 10: Aluminum film 11: Bonding wire

Claims (7)

[Claims] 1. A CCD provided with a photosensitive element group that generates electric charges by photoelectric conversion, a light transmitting unit that transmits light to the CCD, a reflection storing the CCD, and a reflection generated from the transmitted light. An envelope holding the light transmitting means so that light is deviated from the photosensitive element group. 2. A CCD provided with a photosensitive element group that generates charges by photoelectric conversion, a substrate having a surface through which light is transmitted to the CCD, a CCD storing the CCD, and An envelope that holds the substrate so that the surface is inclined. 3. A CCD having a first surface provided with a photosensitive element group that generates charges by photoelectric conversion, a substrate having a second surface through which light is transmitted to the CCD, and storing the CCD. The length of the shortest straight line perpendicular to the normal vector of the first surface and included in the first surface is t, the distance between each of the photosensitive elements and the second surface is L, Is the angle between the surface of the second surface and the second surface is θ (0 <θ
<180 °), an envelope that holds the substrate so as to satisfy θ> tan ⁻¹ (t / L). 4. The substrate is held by the envelope so that the substrate is inclined with respect to a light receiving surface of the sensitivity element group in a cross section of the sensor in a direction orthogonal to the arrangement direction of the sensitivity element group. The sensor according to claim 3, wherein: 5. The device according to claim 1, wherein the substrate is held by the envelope so that the substrate is inclined with respect to a light receiving surface of the sensitivity element group in a cross section in the arrangement direction of the sensitivity element group. Item 3. The sensor according to Item 3. 6. The substrate is held by the envelope so that the substrate is inclined with respect to a light receiving surface of the group of sensitivity elements in a cross section of the sensor in a direction orthogonal to the arrangement direction of the group of sensitivity elements. The sensor according to claim 4, wherein: 7. The substrate is held by the envelope so that the substrate is inclined with respect to a light receiving surface of the sensitivity element group in a cross section in the arrangement direction of the sensitivity element group. Item 7. The sensor according to Item 4.