JP2005037451A - Manuscript size sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a document size sensor that realizes the miniaturization of its external shape and that prevents specular reflection light or stray light from entering a light receiving element side. <P>SOLUTION: Between a light emitting element 110 and a light emitting lens 120, a light shielding layer 150 is arranged as a means for shielding specular reflection light components. The optical axis of the light emitting element 110 and that of the light emitting lens 120 are coincide with each other. In addition, in the light shielding layer 150, a pin hole 150h is prepared, and the center of this pin hole 150h is coincide with the optical axis of the light emitting element 110 and that of the light emitting lens 120. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a document size sensor that employs a triangulation method, and more specifically, to reduce the influence of specular reflection light and stray light reflected on a glass surface on which a distance measurement object is placed, thereby reducing signal light. The present invention relates to a structure of a document size sensor that can detect only (reflected light component).
[0002]
[Prior art]
A document size sensor is used in a document reading device in a copying machine, a complex FAX, or the like. The document size sensor will be described with reference to FIG. The document size sensor 500 is provided with a light emitting element 510 and a light receiving element 540 on the same substrate 501 at a predetermined distance. A light emitting lens 520 is provided above the light emitting element 510 with an interlayer film 502 interposed therebetween, and a condenser lens 530 is provided above the light receiving element 540 with an interlayer film 502 interposed therebetween.
[0003]
A method of detecting the distance to the distance measuring object 700A (reflecting object A) by using the document size sensor 500 by the triangulation method is to place the distance measuring object 700A on the glass substrate 600 and to measure the distance. The presence of the distance measuring object 700A is detected as a spot a that is reflected by the lower surface of the object 700A and received by the light receiving element 540.
[0004]
In the case of the distance measurement object 700B positioned above the distance measurement object 700A, the light receiving element 540 reflects the surface on the lower surface side of the distance measurement object 700B (reflection object B) and receives the light. The presence of the distance measuring object 700B is detected as the spot b. When the spot moves to the side farther from the light receiving element 540 than the spot b in the light receiving element 540, it is determined that the distance measuring object (such as a document) is “present”. On the other hand, in the case of the distance measuring object 700C (reflecting object C), since the spot c is detected on the light receiving element 540 side with respect to the spot b, it is determined that the distance measuring object 700C (document etc.) does not exist. Will be.
[0005]
Here, in the document size sensor 500, the emitted light 1 from the light emitting element 510 is transmitted through the light emitting lens 520 and projected onto the distance measuring object 700, and the reflected light is irregularly reflected from the distance measuring object 700. Is collected by the condenser lens 530 and received by the light receiving element 540, thereby detecting the distance to the distance measuring object 700. However, as shown in FIG. 10, the incident light of the specularly reflected light 1 </ b> A into the light receiving element 540 becomes a problem.
[0006]
With reference to FIG. 9 again, there is no problem if the spot a is formed by the reflected light of the distance measuring object 700A, for example, but when the regular reflected light 1A enters the light receiving element 540, the light intensity Therefore, a spot b is formed in a pseudo manner. As a result, since an erroneous detection occurs and an accurate distance to the distance measuring object 700A cannot be measured, the reliability of the determination of the presence or absence of the distance measuring object 700A is lowered. Such a problem causes a similar problem not only by specular reflection light but also by generation of stray light.
[0007]
Therefore, in order to prevent such erroneous detection by the regular reflection light 1A, as shown in FIG. 11, in order to prevent the regular reflection light 1A from entering the light receiving element 540 side, radiation from the light emitting element 510 is performed. The light emitting element 510 is inclined so that the light emitting optical axis of the light 1 intersects the perpendicular of the glass substrate 600.
[0008]
The following Patent Document 1 is cited as a document size sensor that is used to determine whether or not there is a distance measuring object.
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 06-027546
[Problems to be solved by the invention]
However, when the light emitting element 510 is disposed at an inclination, the outer shape (thickness) of the document size sensor 500 is increased. (See FIG. 11: A> B). At present, copying machines, complex FAX machines, and the like have been downsized, and it is necessary to downsize the document size sensor.
[0011]
By projecting the light emitting optical axis of the light emitting element 510 perpendicularly to the glass surface, it is possible to reduce the outer shape of the document size sensor, but as described above, the side of the regular reflected light 1A on the light receiving element 540 side. It is not possible to prevent light from entering. In addition, even when the stray light that directly enters the light receiving element 540 increases, erroneous detection occurs, and thus an accurate distance to the distance measuring object 700A cannot be measured.
[0012]
Accordingly, the present invention has been made in order to solve the above-mentioned problems, and a first object is to realize downsizing of the outer shape of the document size sensor and to allow regular reflected light to enter the light receiving element side. An object of the present invention is to provide a document size sensor that can be blocked. A second object is to provide a document size sensor that can prevent stray light from entering the light receiving element side.
[0013]
[Means for Solving the Problems]
In order to solve the above problem, according to one aspect of the document size sensor according to the present invention, the radiated light from the light emitting element is transmitted through the light emitting lens to project the distance measuring object, and the distance measuring A document size sensor for detecting the distance to the distance measuring object by condensing reflected light diffusely reflected from the object by a condensing lens and receiving it by a light receiving element. Is provided.
[0014]
The light emitting element is disposed so that the light emission optical axis of the emitted light from the light emitting element is perpendicular to the surface of the distance measuring object, and the distance measuring object is disposed between the light emitting element and the light receiving element. In order to use the reflected light that is irregularly reflected from the light, regular reflected light component shielding means for shielding the regular reflected light component from the light projected from the light emitting lens is provided.
[0015]
As described above, when the specular reflection light component blocking means is provided, the generation of the specular reflection light is prevented, and the emission optical axis of the radiated light from the light emitting element is arranged to be perpendicular to the surface of the object to be measured. Even so, the distance to the object to be measured can be accurately detected. As a result, it is possible to reduce the size of the document size sensor without reducing the reliability of detection of the presence / absence of a distance measurement object. As a result, it is possible to further reduce the size of a copying machine, a composite FAX, or the like.
[0016]
In order to solve the above problem, according to an aspect of the document size sensor according to the present invention, the radiated light from the light emitting element is transmitted through the light emitting lens and projected onto the distance measuring object. A document size sensor that detects the distance to the distance measurement object by condensing reflected light diffusely reflected from the distance measurement object with a condenser lens and receiving the light with a light receiving element. With the features of
[0017]
Between the light emitting element and the light receiving element, there is provided stray light shielding means for shielding stray light that is irradiated from the light emitting element to the light receiving element without passing through the light emitting lens.
[0018]
Thus, by providing the stray light blocking means, the stray light is prevented from entering the light receiving element, and only the signal light can enter the light receiving element. Thereby, it is possible to accurately detect the distance to the distance measurement object, and to ensure high reliability in detecting the presence or absence of the distance measurement object.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The configuration of the document size sensor in each embodiment based on the present invention will be described below with reference to the drawings.
[0020]
<Embodiment 1>
With reference to FIG. 1, the configuration of document size sensor 100A in the present embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of document size sensor 100A in the present embodiment.
[0021]
In document size sensor 100A in the present embodiment, light emitting element 110 and light receiving element 140 are provided on the same substrate 101 at a predetermined distance. As the light emitting element 110, for example, a light emitting diode (LED) is used, and as the light receiving element 140, a semiconductor position detecting element (PSD: Position Sensitive Photodetector) is used.
[0022]
A light emitting lens 120 is provided above the light emitting element 110 with an interlayer film 102 interposed therebetween, and a condenser lens 130 is provided above the light receiving element 140 with an interlayer film 102 interposed therebetween.
[0023]
In addition, a characteristic configuration of the present embodiment is that a light shielding layer 150 as a regular reflection light component light shielding unit is provided between the light emitting element 110 and the light emitting lens 120. In this embodiment mode, the light emitting optical axis of the light emitting element 110 and the optical axis of the light emitting lens 120 are provided to coincide with each other, and the light blocking layer 150 is provided with a pinhole 150h. The center of the pinhole 150h is provided so that the optical axes of the light emitting element 110 and the light emitting lens 120 coincide. The planar shape of the light shielding layer 150 is not particularly limited, and various shapes such as a circle, a rectangle, a polygon, and the like can be adopted. The light shielding layer 150 is made of polycarbonate or the like.
[0024]
<Action and effect>
Thus, by providing the light shielding layer 150 having the pinhole 150 h between the light emitting element 110 and the light emitting lens 120, the specular reflection light component is shielded from the light projected from the light emitting lens 120 in the light shielding layer 150. It becomes possible. As a result, the S / N is improved by preventing the generation of regular reflection light in the reflected light irregularly reflected from the distance measuring object 700, and more accurate measurement can be performed.
[0025]
In the document size sensor 100A in the present embodiment, the distance between the light emitting element 110 and the light receiving element 140 is about 20 mm to 40 mm, between the light emitting element 110 and the light emitting lens 120, and between the light receiving element 140 and the light collecting element. The distance between the lens 130 is about 3 mm to 6 mm, the thickness of the light shielding layer 150 is about 0.5 mm to 1.5 mm, and the distance between the light emitting lens 120 and the light shielding layer 150 is about 3 mm. ˜6 mm, and it is not uniquely determined by the shape of each lens, the shape of the pinhole 150h, the directivity, the focal length, and the detection distance of the light emitting element 110, but the diameter of the pinhole 150h is about φ0.5 mm. It is about ~ 1.5mm. It should be noted that the document size sensor 100A can be manufactured using a general semiconductor manufacturing technique.
[0026]
<Embodiment 2>
Next, the configuration of document size sensor 100B in the present embodiment will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the configuration of document size sensor 100B in the present embodiment. It should be noted that the same configuration as that of document size sensor 100A shown in the first embodiment is denoted by the same reference numeral, and redundant description will not be repeated, and only characteristic portions will be described in detail. The same applies to Embodiments 3 to 8 described below.
[0027]
The document size sensor 100B according to the present embodiment is characterized in that a mold member 160 including a pinhole 160h is provided as a regular reflection light component light shielding unit in contact with the lower surface side of the light emitting lens 120 instead of the light shielding layer 150 described above. There is in point. The design conditions required for the mold member 160 and the pinhole 160h are the same as those in the first embodiment. The mold member 160 is made of polycarbonate or the like.
[0028]
<Action and effect>
Also in the present embodiment, it is possible to obtain the same function and effect as in the first embodiment. It should be noted that the document size sensor 100B according to the present embodiment can be manufactured using a general semiconductor manufacturing technique.
[0029]
<Embodiment 3>
Next, the configuration of document size sensor 100C in the present embodiment will be described with reference to FIG. 3A is a cross-sectional view illustrating the configuration of the document size sensor 100C according to the present embodiment, and FIG. 3B is a diagram illustrating the configuration of a case member 170 described later.
[0030]
A feature of the document size sensor 100C in the present embodiment is that a case member 170 including a pinhole 170h is provided so as to cover the light emitting element 110 as a regular reflection light component light shielding unit instead of the light shielding layer 150 described above. It is in. The case member 170 includes an upper wall portion 171 that covers the upper surface of the light emitting element 110, and a side wall portion 172 that surrounds the entire periphery of the peripheral portion of the upper wall portion 171 and hangs down from the peripheral portion. The design conditions required for case member 170 and pinhole 170h are the same as those in the first embodiment. The case member 170 is made of polycarbonate or the like.
[0031]
<Action and effect>
Also in the present embodiment, it is possible to obtain the same function and effect as in the first embodiment. It should be noted that the document size sensor 100C according to the present embodiment can be manufactured using a general semiconductor manufacturing technique.
[0032]
<Embodiment 4>
Next, the configuration of document size sensor 100D in the present embodiment will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a configuration of document size sensor 100D in the present embodiment.
[0033]
The document size sensor 100D according to the present embodiment has the same basic configuration as that of the first embodiment, except for the optical axis (L1) of the light-emitting lens 120 and the central axis of the pinhole 150h. The light emitting lens 120 and the pinhole 150h are arranged so as to deviate from (L2) (x in FIG. 4), and the optical axis of the emitted light L3 emitted from the light emitting element 110 is further away from the light receiving element 140. The radiated light L3 is irradiated from the light emitting element 110 so as to be inclined to intersect the optical axis (L1) of the light emitting lens 120.
[0034]
<Action and effect>
According to the configuration in the present embodiment, the probability that regular reflection light is generated can be further reduced by inclining the optical axis of the emitted light L3 emitted from the light emitting element 110 in the direction away from the light receiving element 140. Make it possible. It should be noted that the document size sensor 100D according to the present embodiment can be manufactured using a general semiconductor manufacturing technique. The configuration in the present embodiment can also be applied to the configurations in the second and third embodiments.
[0035]
<Embodiment 5>
Next, the configuration of document size sensor 100E in the present embodiment will be described with reference to FIG. FIG. 5 is a cross-sectional view showing a configuration of document size sensor 100E in the present embodiment.
[0036]
The document size sensor 100E according to the present embodiment is characterized by stray light shielding between the light emitting element 110 and the light receiving element 140 that blocks the stray light 1B that is irradiated from the light emitting element 110 to the light receiving element 140 without passing through the light emitting lens 120. The light shielding wall 200 is provided so as to extend in the vertical direction as a means. In the present embodiment, the light shielding wall 200 is provided so as to penetrate the substrate 101. The light shielding wall 200 is formed of a conductive resin or the like and has a wall thickness of about 0.5 mm to 1.5 mm.
[0037]
<Action and effect>
In the present embodiment, the light emitting element 110 and the light receiving element 140 are not transmitted even though the stray light 1B irradiated to the light receiving element 140 due to irregular reflection in the interlayer film 102 without passing through the light emitting lens 120. By providing the light shielding wall 200 between them, it is possible to block the incoming light of the stray light 1B to the light receiving element 140. As a result, the S / N is improved and more accurate measurement can be performed. It should be noted that the document size sensor 100E according to the present embodiment can be manufactured using a general semiconductor manufacturing technique.
[0038]
<Embodiment 6>
Next, the configuration of document size sensor 100F in the present embodiment will be described with reference to FIG. FIG. 6 is a cross-sectional view showing a configuration of document size sensor 100F in the present embodiment.
[0039]
The document size sensor 100F according to the present embodiment is characterized in that a light shielding wall 200 is provided as stray light shielding means, and a light shielding pattern layer 210 is provided on the lower surface side of the substrate 101 on which the light emitting element 110 is placed. . The light shielding pattern layer 210 is made of a copper foil and has a thickness of about 35 μm. The light shielding wall 200 is provided only on the upper side of the substrate 101.
[0040]
<Action and effect>
Also in the present embodiment, the light shielding wall 200 and the light shielding pattern layer 210 can block the stray light 1B from entering the light receiving element 140, so that the same effect as the fifth embodiment can be obtained. Is possible. It should be noted that the document size sensor 100F according to the present embodiment can be manufactured using a general semiconductor manufacturing technique.
[0041]
<Embodiment 7>
Next, the configuration of document size sensor 100G in the present embodiment will be described with reference to FIG. FIG. 7 is a cross-sectional view showing a configuration of document size sensor 100G in the present embodiment.
[0042]
The document size sensor 100G according to the present embodiment is characterized in that a case member 220 including a pinhole 220h is provided so as to cover the light emitting element 110 as stray light shielding means. The case member 220 includes an upper wall portion 221 that covers the upper surface of the light emitting element 110, and a side wall portion 222 that surrounds the entire periphery of the peripheral portion of the upper wall portion 221 and hangs down from the peripheral portion. The design conditions required for case member 220 and pinhole 220h are the same as those in the first embodiment.
[0043]
<Action and effect>
Also in the present embodiment, the case member 220 can block stray light 1 </ b> B from entering the light receiving element 140, so that the same operational effects as those of the fifth embodiment can be obtained. It should be noted that the document size sensor 100G according to the present embodiment can be manufactured using a general semiconductor manufacturing technique.
[0044]
<Eighth embodiment>
Next, the configuration of document size sensor 100H in the present embodiment will be described with reference to FIG. FIG. 8 is a cross-sectional view showing a configuration of document size sensor 100H in the present embodiment.
[0045]
The document size sensor 100H according to the present embodiment is characterized in that a mold member 230 that covers the upper surface side of the light emitting element 110 and includes a pinhole 230h is provided as stray light shielding means. The design conditions required for the mold member 230 and the pinhole 230h are the same as those in the first embodiment.
[0046]
<Action and effect>
Also in the present embodiment, since the mold member 230 can block the incoming stray light 1B to the light receiving element 140, it is possible to obtain the same effects as those of the fifth embodiment. It should be noted that the document size sensor 100H according to the present embodiment can be manufactured using a general semiconductor manufacturing technique.
[0047]
It should be noted that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0048]
【The invention's effect】
According to the document size sensor based on the present invention, it is possible to provide a document size sensor having high reliability in detection and measurement accuracy.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a document size sensor according to a first embodiment based on the present invention.
2A is a cross-sectional view and FIG. 2B is a cross-sectional view taken along line BB in FIG. 2A showing a configuration of a document size sensor according to the second embodiment of the present invention.
3A is a sectional view and FIG. 3B is an enlarged view showing a configuration of a document size sensor according to a third embodiment of the present invention.
FIGS. 4A and 4B are a cross-sectional view and a partial enlarged view of a configuration of a document size sensor according to a fourth embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a configuration of a document size sensor according to a fifth embodiment based on the present invention.
FIG. 6 is a cross-sectional view showing a configuration of a document size sensor according to a sixth embodiment based on the present invention.
FIGS. 7A and 7B are a cross-sectional view and a partial enlarged view of a configuration of a document size sensor according to a seventh embodiment of the present invention.
FIG. 8 is a sectional view showing a configuration of a document size sensor according to an eighth embodiment based on the present invention.
9A is a cross-sectional view illustrating a first configuration of a document size sensor in the prior art, and FIG. 9B is a partially enlarged view thereof.
FIG. 10 is a schematic diagram showing a problem of a document size sensor in the prior art.
FIG. 11 is a cross-sectional view showing a second configuration of a document size sensor in the prior art.
[Explanation of symbols]
100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H Document size sensor, 101 substrate, 102 interlayer film, 110 light emitting element, 120 light emitting lens, 130 condenser lens, 140 light receiving element, 150 light shielding layer, 150h, 160h , 170h, 220h, 230h Pinhole, 160, 230 Mold member, 170, 220 Case member, 171, 221 Upper wall portion, 172, 222 Side wall portion, 200 Light shielding wall, 210 Light shielding pattern layer.

Claims (10)

The emitted light from the light emitting element is transmitted through the light emitting lens and projected onto the object to be measured, and the reflected light irregularly reflected from the distance measuring object is condensed by the condenser lens and received by the light receiving element. A document size sensor for detecting a distance to the object to be measured by
The light emitting element is arranged so that the emission optical axis of the emitted light from the light emitting element is perpendicular to the surface of the object to be measured,
Between the light emitting element and the light receiving element, the specularly reflected light component is shielded from the light projected from the light emitting lens in order to prevent the occurrence of specularly reflected light in the reflected light irregularly reflected from the distance measuring object. A document size sensor, comprising: a regularly reflected light component light shielding means. Between the light emitting element and the light emitting lens, the specular reflection light component light shielding means is provided,
The light shielding means includes a light shielding member including a pinhole.
The document size sensor according to claim 1. The regular reflection component light shielding member is:
The document size sensor according to claim 2, wherein the document size sensor is a mold member including the pinhole, which is provided on a lower surface side of the light emitting lens. The said regular reflection light component light shielding member is a case member provided between the said light emitting element and the said light emitting lens, and is provided so that it may cover the said light emitting element while including the said pinhole. Document size sensor. The light emitting lens and the pinhole are arranged so that the optical axis of the light emitting lens and the central axis of the pinhole are shifted,
The emitted light is emitted from the light emitting element so that an optical axis of the emitted light emitted from the light emitting element is inclined in a direction away from the light receiving element and intersects an optical axis of the light emitting lens. Item 5. The document size sensor according to any one of Items 2 to 4. The emitted light from the light emitting element is transmitted through the light emitting lens and projected onto the object to be measured, and the reflected light irregularly reflected from the distance measuring object is condensed by the condenser lens and received by the light receiving element. A document size sensor for detecting a distance to the object to be measured by
A document size sensor, comprising: stray light shielding means for shielding stray light that is irradiated from the light emitting element to the light receiving element without passing through the light emitting lens between the light emitting element and the light receiving element. The document size sensor according to claim 6, wherein the stray light shielding unit is a light shielding wall provided between the light emitting element and the light receiving element. The document size sensor according to claim 6, wherein the stray light shielding unit is a light shielding pattern layer provided on a lower surface side of the light emitting element. The document size sensor according to claim 6, wherein the stray light blocking unit is a case member including a pinhole and provided to cover the light emitting element. The document size sensor according to claim 6, wherein the stray light blocking unit includes a pinhole and is a mold member provided so as to cover the light emitting element.

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