JP2000032222A - Original image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read an original image without misdetection by regulating a shape of luminous flux of at least one of division components in a crossing direction of a luminous flux with astigmatism originated from a projected scanning light and reflected in an original receiving the scanning light and receiving the luminous flux. SOLUTION: Before the original image reader 0 reads an image of an original (O), a scanning light projection means 2 projects a scanning light to detect presence of the original (O) placed on an original platen 1 and a light receiving means 3 regulates a shape of luminous flux of at least one of division components in a crossing direction of a luminous flux with astigmatism originated from the projected scanning light and reflected in the original (O)and receives the luminous flux to detect position and size information of the original(O) to be read in advance so that a size of feeding paper corresponding to the size of the original(O) is selected and an amount of position deviation and a tilt or the like are displayed when the original (O) is deviated from a reference position. Even when the original (O) is not correctly placed, the placing of the original (O) is corrected to read the image of the original (O) accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document image reading apparatus, and more particularly, to a method of reading a document image by detecting the presence or absence of a document placed on a document table such as a copying machine, a facsimile machine, or a scanner. The present invention relates to a document image reading device.

[0002]

2. Description of the Related Art Conventionally, when reading a document image in a copying machine, a facsimile device, a scanner, or the like, a document image reading device performs optical scanning to read a range of the document image and a type of paper to be copied. In order to determine the size of a document, a document detection sensor is used, or a scanner is scanned once, and the size of the document is determined by a method called pre-scan in which the size of the document is read (Japanese Unexamined Patent Application Publication No. See Japanese Unexamined Patent Publication No. 5-58511).

In such a document detection sensor, since only one sensor can obtain information of only a few points, it is necessary to use a plurality of sensors in order to determine the size of other types of documents. .

In addition, the original detection by the pre-scan has disadvantages such as that the first copy is delayed, and that the operator takes out the original by mistakenly performing the pre-scan operation as a real copying operation of the original image.

Therefore, as a means for obtaining a large amount of information with one sensor, an optical scanning type document image reading apparatus is known (see Japanese Patent Application Laid-Open No. 6-242391).

In FIG. 16, such an optical scanning type original image reading apparatus 100 is a copying machine, and the sensor main body is a hologram scanner 10 as optical scanning means.
1. Perforated mirror 102, semiconductor laser 1 as light source
03, comprising a photodetector 104 as scanning light detecting means.

A laser beam emitted from a semiconductor laser 103 as a light source passes through a hole 102a of a perforated mirror 102, and a hologram scanner 1 as an optical scanning means.
01 is incident.

Hologram scanner 10 as scanning means
Numeral 1 diffracts the laser light and rotates the laser light so that the diffracted laser light scans the contact glass 105 on which the document (O) is placed in a circular shape.

The light scanning on the contact glass 105 passes through the portion where the document (O) is not present, but scatters at the portion where the document (O) is present. Come back to.

The returned light is reflected by the mirror portion 102b of the perforated mirror 102, and is detected by a photodetector 104 as scanning light detecting means.

As described above, the portion where the document (O) exists on the contact glass 105 has its signal detected by the photodetector 104 as the scanning light detecting means, and the portion where the document does not exist has the light detecting function as the scanning light detecting means. Since the signal from the device 104 is not detected, the presence or absence of the original (O) in the scanning line can be detected, and further information such as the size and position of the original (O) can be extracted.

However, an optical scanning type document sensor using such a recursive optical system attempts to determine the presence or absence of a document based on the light intensity of the reflected light. As in O), there is a problem that the light is reflected and detected.

Therefore, a document edge detecting device for detecting the size of a document without being influenced by the image density of the document or the contamination of the pressure plate for pressing the document is also known (see Japanese Patent Application Laid-Open No. 9-163083).

Referring to FIG. 17, such an optical scanning type document image reading apparatus 200 includes a light source 2 in a copying machine.
The light emitted from the light source 01 is returned by a light splitting element 202 of a half mirror, a perforated mirror or a partial reflection mirror, and is irradiated on a scanning mirror 203.

The light reflected by the scanning mirror 203 scans the contact glass 204, is scattered and reflected by the original (O) or the pressure plate 205, and is reflected by the light receiving lens 206.
And irradiates the light receiving element 208 via a wedge or a cylindrical lens 207. At this time, the cylindrical lens 2
07, the beam shape changes depending on the reflected distance. This changes depending on the direction of the cylindrical lens 207 or the wedge.

Here, the cylindrical lens 207 is the light receiving element 2
Since the photodiode 08 is inserted so as to have a light condensing action in the horizontal direction, the horizontal focal length of the light receiving element 208 on the photodiode is shorter than the vertical focal length, and even at the same object position. Since the image has two focal points in the vertical and horizontal directions, the focal position is closer to the cylindrical lens 207 in the horizontal direction than in the vertical direction.

Similarly, since the image side also has two focal positions on the object side, when the photodiode of the light receiving element 208 is fixed on the image side, the light is condensed in the vertical direction when the optical path length is long. Since the horizontal direction is blurred, the shape becomes a horizontally long ellipse as shown in FIG. 18A, and when the optical path length is short, the shape becomes a vertically long ellipse as shown in FIG. 18C. At an intermediate distance between them, the ellipse changes from a horizontally long ellipse to a vertically long ellipse smoothly, and becomes a circular state as shown in FIG.

In the astigmatism method, a 2 × 2 light receiving surface is used, and distance detection is performed based on a calculation result of “(A1 + A2) − (B1 + B2)”.

For example, when the optical system is adjusted so as to form a circular beam as shown in FIG. 18B at an intermediate distance between the pressure plate 205 and the original (O) in FIG. 17, "(A1 + A2)" -(B1 + B2) "is a signal as shown in FIG.

If this is binarized according to the threshold level, as shown in FIG. 19B, a signal of only the original (O) portion excluding the pressure plate 205 can be extracted. By measuring the width of the signal, the angle at which the edge is output, the time from the reference value, and the like, the position and size of the placed original (O) can be detected.

However, a copying machine or the like on which such an optical scanning type document image reading device 200 is mounted is usually used under illumination such as a fluorescent lamp 209. Further, even if the copy start button is pressed while the document (O) is held down by hand, copying is possible, so that there is often a lighting device such as a fluorescent lamp 209 on the scanning line of the optical scanning as shown in FIG. .

In such a case, the image of the fluorescent lamp 209 is considerably blurred because it is far away from the focal position.
As a large light image (C) as shown in FIG.
08 across the photodiode surface.

At this time, "(A1 + A2)-(B1 + B
Performing the calculation of "2)""has caused a problem that, as shown in FIG. 22, even a portion having no original (O) is erroneously detected as a signal.

[0024]

In the above-described conventional document image reading apparatus, there is a problem in that a part without the document (O) is erroneously detected as a signal due to disturbance light such as illumination of a fluorescent lamp. I was

An object of the present invention is to solve such a problem. That is, it is an object of the present invention to provide a document image reading apparatus that detects the presence or absence of a document placed on a document table and reads a document image without erroneous detection even when there is disturbance light such as illumination of a fluorescent lamp. Aim.

[0026]

According to one aspect of the present invention, there is provided a document image reading apparatus for detecting the presence or absence of a document placed on a document table and reading a document image. A document placing table for placing a document, scanning light projecting means for projecting scanning light for detecting the presence / absence of a document placed on the document placing table, and projecting light to the scanning light projecting means. A document image reading apparatus which comprises a light receiving means for restricting and receiving a light beam shape of at least one component of a reflected light beam having astigmatism from a lighted document and dividing the reflected light beam into components intersecting each other. Main features.

According to a second aspect of the present invention, in the original image reading apparatus according to the first aspect, the main feature is that the scanning light projecting means is an original image reading apparatus including a condensing means.

According to a third aspect of the present invention, in the document image reading apparatus according to the first or second aspect, the scanning light projecting means comprises:
The main feature is that the scanning means is a document image reading device comprising a diffraction grating.

According to a fourth aspect of the present invention, in the document image reading apparatus according to the first or second aspect, the scanning light projecting means includes:
The main feature is that the scanning means is a document image reading device comprising a prism.

According to a fifth aspect of the present invention, in the original image reading apparatus according to the first, second, third, or fourth aspect, the main feature is that the light receiving means is an original image reading apparatus comprising a cylindrical lens.

The present invention according to claim 6 is based on claims 1, 2, 3,
The main feature of the original image reading apparatus according to 4 or 5 is that the light receiving means is an original image reading apparatus including a light splitting means for splitting a reflected light beam into components in a direction intersecting each other.

The present invention according to claim 7 is based on claims 1, 2, 3,
The document image reading device according to 4, 5, or 6, is characterized in that the light dividing means is a document image reading device including a half mirror.

The present invention according to claim 8 is based on claims 1, 2, 3,
4. The document image reading apparatus according to 4, 5, 6, or 7, wherein the light receiving means regulates a light flux shape of at least one of the reflected light flux having astigmatism from the document divided into components in a direction intersecting each other. The main feature of the present invention is that it is a document image reading apparatus comprising:

The present invention according to claim 9 is based on claims 1, 2, 3,
The document image reading device according to 4, 5, or 6, is characterized in that the light dividing means is a document image reading device including a partially transmitting mirror.

According to a tenth aspect of the present invention, there is provided the first and second aspects.
The document image reading device according to 3, 4, 5, or 6, is characterized in that the light dividing means is a document image reading device including a partially reflecting mirror.

The present invention according to claim 11 is based on claims 1, 2,
The document image reading device according to 3, 4, 5, or 6, is characterized in that the light dividing means is a document image reading device having a perforated wedge.

The twelfth aspect of the present invention is the first aspect of the present invention.
The main feature of the document image reading device described in 3, 4, 5 or 6 is that the light dividing means is a document image reading device having a partial wedge.

The present invention according to claim 13 is based on claims 1, 2,
The main feature of the document image reading device described in 3, 4, 5, or 6 is that the light dividing means is a document image reading device including a partial analysis grid.

According to a fourteenth aspect of the present invention,
The document image reading device according to 3, 4, 5, or 6, is characterized in that the light dividing means is a document image reading device including a light receiving area dividing means for dividing a light receiving area of a light receiver.

According to a fifteenth aspect of the present invention, in the document image reading apparatus according to the fourteenth aspect, the light receiving area dividing means comprises:
The main feature is that it is a document image reading device in which the light receiving area of the light receiver is divided into three.

[0041]

According to the first aspect of the present invention, there is provided a document image reading apparatus configured as described above, wherein a scanning light projecting unit for projecting scanning light for detecting the presence or absence of a document placed on a document placing table is provided. Illuminating the fluorescent lamp by controlling the light flux shape of at least one of the reflected light fluxes having astigmatism from the projected original document and dividing the reflected light fluxes into components in directions intersecting by the light receiving means; It is possible to provide a document image reading apparatus that detects the presence or absence of a document placed on a document table and reads a document image without erroneous detection even when there is disturbance light.

According to a second aspect of the present invention, a scanning light projecting means having a light condensing means for projecting a scanning light for detecting the presence or absence of a document placed on a document placing table is used to illuminate the document from the projected document. The reflected light beam having astigmatism is divided into components in the direction intersecting by the light receiving means, and the light beam shape of at least one component is regulated so as to be received, so that even if there is disturbance light such as illumination of a fluorescent lamp. Original image reading, where the light from the light source efficiently illuminates the original on the contact glass of the original placing table, detects the presence of the original placed on the original table without erroneous detection, and reads the original image. Equipment can be provided.

According to the third aspect of the present invention, the scanning means for projecting scanning light for detecting the presence or absence of a document placed on the document table is projected by the scanning light projecting means having a diffraction grating. The reflected light beam having astigmatism from the original document is divided into components in the direction intersecting by the light-receiving means, and the light beam shape of at least one of the components is regulated so as to be received. Even if there is, the image formed on the document at any position becomes constant,
It is possible to provide a document image reading device that reliably prevents erroneous detection and detects the presence or absence of a document placed on a document table to read a document image.

According to the fourth aspect of the present invention, the scanning means for projecting the scanning light for detecting the presence or absence of the original placed on the original placing table is projected by the scanning light emitting means having a prism. The reflected light beam having astigmatism from the document is received by restricting the light beam shape of at least one of the components divided into components in the direction intersecting by the light receiving means, so that disturbance light such as illumination of a fluorescent lamp can be generated. Even if there is, the image formed on the original at any position becomes constant,
It is possible to provide a document image reading device that reliably prevents erroneous detection and detects the presence or absence of a document placed on a document table to read a document image.

According to the fifth aspect of the present invention, the scanning light projecting means for projecting scanning light for detecting the presence / absence of the document placed on the document table is provided by a cylindrical lens from the projected document. The reflected light beam having astigmatism is divided into components in the direction intersecting by the light receiving means, and the light beam shape of at least one component is regulated so as to be received, so that even if there is disturbance light such as illumination of a fluorescent lamp. Another object of the present invention is to provide a document image reading apparatus for reading a document image in which the presence or absence of a document placed on a document table can be easily detected without erroneous detection.

According to the sixth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the document placed on the document table is provided with astigmatism from the projected document. The reflected light beam having the above is controlled so that the light beam shape of at least one of the components divided in the direction intersecting by the light splitting means of the light receiving means is received, and there is disturbance light such as illumination of a fluorescent lamp. In addition, it is possible to provide a document image reading device that detects the presence or absence of a document placed on a document table and reads a document image without erroneous detection.

According to the seventh aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the document placed on the document table is provided with astigmatism from the projected document. The reflected light beam having the above-mentioned shape is divided into components in the direction intersecting with each other by the half mirror of the light splitting means of the light receiving means, and the light flux shape of at least one of the components is regulated so as to be received. Therefore, it is possible to provide a document image reading apparatus that detects the presence or absence of a document placed on a document table and reads a document image without erroneous detection.

According to the eighth aspect of the present invention, the astigmatism from the projected document is detected by the scanning light projecting means for projecting scanning light for detecting the presence or absence of the document placed on the document table. The reflected light beam having the above shape is divided into components in directions intersecting by the light splitting means of the light receiving means, and the light flux shape of at least one component is regulated by a mask so as to be received. However, it is possible to provide a document image reading apparatus that detects the presence or absence of a document placed on a document table and reads a document image without erroneous detection.

According to the ninth aspect of the present invention, the astigmatism from the projected document is detected by the scanning light projecting means for projecting the scanning light for detecting the presence or absence of the document placed on the document table. The reflected light flux having the above-mentioned is divided into components in the direction intersecting by the partial transmission mirror of the light splitting means of the light receiving means so that the light flux shape of at least one component is regulated and received, and disturbance such as illumination of a fluorescent lamp is performed. It is possible to provide a low-cost, high-maintenance document image reading apparatus that detects the presence or absence of a document placed on a document table without erroneous detection even when there is light, and has a small number of components for reading a document image. Make it possible.

According to a tenth aspect of the present invention, the scanning light projecting means for projecting scanning light for detecting the presence or absence of a document placed on the document table is provided with astigmatism from the projected document. The reflected light flux having the light is divided into components in a direction intersecting by the partial reflection mirror of the light splitting means of the light receiving means, and the light flux shape of at least one of the components is regulated and received. It is possible to provide a low-cost, high-maintenance document image reading apparatus that detects the presence or absence of a document placed on a document table without erroneous detection even when there is light, and has a small number of components for reading a document image. Make it possible.

According to the eleventh aspect of the present invention, astigmatism from the projected document is detected by the scanning light projecting means for projecting scanning light for detecting the presence or absence of the document placed on the document table. The reflected light beam having the shape is controlled to receive the light beam shape of at least one component that is divided into components in the direction intersecting with the perforated wedge of the light splitting device of the light receiving device, so that disturbance such as illumination of a fluorescent lamp is performed. It is possible to provide a low-cost, high-maintenance document image reading apparatus that detects the presence or absence of a document placed on a document table without erroneous detection even when there is light, and has a small number of components for reading a document image. Make it possible.

According to a twelfth aspect of the present invention, the astigmatism from the projected document is detected by the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the document placed on the document table. The reflected light having the above-mentioned is divided into components in the direction intersecting with the partial wedges of the light splitting means of the light receiving means so that the light flux of at least one of the components is regulated and received, and disturbance light such as illumination of a fluorescent lamp is received. Therefore, it is possible to provide a low-cost, high-maintenance document image reading apparatus with a small number of components for detecting the presence or absence of a document placed on a document table without erroneous detection and reading the document image. To do.

According to the thirteenth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the document placed on the document table is provided with astigmatism from the projected document. The reflected light having the above-mentioned is divided into components in the direction intersecting by the partial diffraction grating of the light splitting means of the light receiving means so that the light flux shape of at least one of the components is regulated and received, and disturbance such as illumination of a fluorescent lamp is performed. It is possible to provide a low-cost, high-maintenance document image reading apparatus that detects the presence or absence of a document placed on a document table without erroneous detection even when there is light, and has a small number of components for reading a document image. Make it possible.

According to a fourteenth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the document placed on the document table is provided with astigmatism from the projected document. The reflected light flux having the light receiving area dividing means for dividing the light receiving area of the light receiver of the light splitting means of the light receiving means is divided into components in directions intersecting each other, and the light flux shape of at least one of the components is regulated so as to be received. Therefore, even if there is disturbance light such as illumination of fluorescent lamps, the number of parts for detecting the presence or absence of a document placed on the platen and reading the document image without erroneous detection is small and low cost and high maintenance. A small document image reading device can be provided.

According to a fifteenth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the document placed on the document table is provided with astigmatism from the projected document. The light receiving area dividing means for dividing the light receiving area of the light receiving means of the light receiving means into three light receiving areas is divided into at least one of the components in the direction intersecting with each other. Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, the number of parts for detecting the presence / absence of a document placed on the platen and reading the document image without erroneous detection is small, and versatility is high. Further, it is possible to provide a small-sized document image reading device with low cost and high maintenance.

[0056]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, a document image reading apparatus 0 according to the present invention converts a document image of a document (O) placed on a contact glass of a document placing table 1 such as a copying machine, a facsimile machine, or a scanner into the above-mentioned document. The light is illuminated by an illumination lamp 4 disposed below the contact glass of the original table 1, and can be read by a light receiving element 7 via a mirror group 5 and a lens 6.

The document image reading apparatus 0 detects the presence or absence of the document (O) placed on the document table 1 by the scanning light projecting means 2 before reading the document image of the document (O). Of the reflected light having astigmatism from the document (O) projected onto the scanning light projecting means 2 into at least one of the components in the direction intersecting each other. The shape of the light beam is regulated, the light is received by the light receiving means 3, the position and size information of the original (O) to be read in advance are detected, and a paper feeding size (not shown) corresponding to the size of the original is selected by a paper feeding means (not shown). When the original (O) is displaced from the reference position, the position deviation amount, the inclination, and the like are displayed on display means (not shown), and even when the original (O) is not correctly placed, not shown. Precisely manuscript (O) by proofreading means The image is can be read.

The scanning light projecting means 2 comprises a condensing means 2a comprising a light projecting lens for collimating or condensing light,
A light source 2c for generating light having no astigmatism or light having astigmatism used for detecting the document (O), a light splitting means 2d for splitting an optical path on a light projecting side and a light receiving side, and the light splitting means 2d
Scanning means 2b for deflecting the light reflected by the half mirror to scan on the contact glass of the document table 1.
Consists of

The condensing means 2a comprises a light projecting lens for collimating or condensing light, and can efficiently illuminate the light of the light source 2c on the original (O) on the contact glass of the original mounting table 1, and It is preferable that the beam spot on the contact glass of the document table 1 be designed to be as small as possible.

The condensing means 2a may be a collimating lens if the light source 2c is a light source having a small area, such as an LD. A condensing lens that forms an image on the contact glass is used.

The scanning means 2b has a function of scanning the light from the light source 2c on the contact glass of the document table 1, and is used for a copying machine, for example.
A mirror scanner as shown is used.

As the light source 2c, various light sources such as an LD, a light bulb, and an LED can be used. However, since the light source 2c is generally used in a device operated by a human such as a copying machine, it is possible to secure safety to a human body, to improve light collection efficiency, LEDs are most desirable over low power.

As the light splitting means 2d, a beam splitter such as a half mirror, a partial reflection mirror, or a partial transmission mirror is used.

[0065] The light receiving means 3 includes a cylindrical lens 3a, the beam splitter and the mask _{A3b 11} without the half mirror 3b ₁ or illustrated light splitting means 3b and the mask _{B3b 12}
When a light receiver A3c ₁ of the light receiving elements of the photodetector 3c photodetector B
3c ₂ and a condenser lens 3d.

The light splitting means 3b is provided with the cylindrical lens 3
a, the light passing through the condenser lens 3d
3c ₁ and the half mirror 3b ₁ for guiding to the light receiver B3c ₂ and through the two sets of the mask _{A3b 11} and the mask _{B3b 12,} original document projected on the scanning light projecting means 2 ( It is used to regulate the light beam shape of at least one component obtained by dividing the reflected light beam having astigmatism from O) into components in the direction crossing each other.

The mask A3b ₁₁ and the mask B
Reference numeral 3b ₁₂ denotes a portion for transmitting or blocking only a necessary region from the condensed light, at a position where reflected or scattered light from the original (O) is imaged by the cylindrical lens 3a and the condensing lens 3d. The mask A3b _{11 is} arranged and
Or at least one of the shape of the mask B3b ₁₂ is equal or similar to the shape of the image formed, the light receiver 3
one transparent pattern on the light receiver A3c ₁ of c, no mask or reverse light shielding pattern is used on the other of said light receiver B3c _2.

[0068] In the light receiver A3c ₁ and the light receiver B3c ₂ of the light-receiving unit 3c is usually a photodiode (PD)
Is used. Although various photodiodes (PDs) are used, those having high sensitivity to the wavelength of the light source 2c are preferable, and the half mirror 3b of the light splitting means 3b is preferably used.
_The light beam divided by ₁ is disposed at a position where the light beam can be efficiently received.

The scanning light having no or astigmatism emitted from the light source 2 c of the scanning light projecting means 2 irradiates the contact glass of the document table 1. The contact glass of the original mounting table 1 is made of glass through which light passes. If there is no original (O), the original glass passes through the glass as it is, and if there is the original (O), scattering occurs due to the original (O).

[0070] the document scanning light scattered by the (O) is the cylindrical lens 3a, is focused by the condenser lens 3d, the mask _{A3b 11,} the mask _{B3b 12}
Only the light that has passed through is received by the light receiver A3c of the light receiver 3c.
_1, is detected by the light receiver B3c _2.

The scanning light emitted from the light source 2c is
If there is no astigmatism, the cylindrical lens 3a is indispensable.
Although a is not indispensable, if it is arranged as shown in the figure, the astigmatism is enlarged and emphasized, so that the detection is easily performed.

At this time, astigmatism occurs due to the cylindrical lens 3a disposed in the optical system, and the mask A3
b _11, the light receiving pattern at the imaging position for the original (O), which he placed the above mask B3b ₁₂ may change shape in response to the detected distance as in FIG.

For example, the position of the pressure plate 8 at the detection timing
Is half-open, so the entrance path is
Is long and horizontally long with respect to the vertically long shape of the position of the original (O)
become. In this position, as shown in FIG.
Mask A3b at the position ₁₁Is placed,
The light receiver A3c of the light receiver 3c₁Side, manuscript
The reflected light from an object farther than the position (O) is
3b₁₁The light receiver A3c₁Light incident on
Is reduced, and conversely, the light receiver B3c₂Side, manuscript
All light at the position is blocked, and the farther the object
To increase.

[0074] In order to determine the signal from the actual document (O) performs the subtraction of the light receiver A3c ₁ and the light receiver B3c _2, by exceeding the threshold level at which the signal is set, there is a document It is convenient to use signal processing for determining

As a signal processing method, the received light signal is set to A /
There are various methods such as D conversion and digital processing,
Any means may be used. As an example, a method of detecting a difference signal of the light receiver A3c ₁ and the light receiver B3c _2.

When there is an original (O) on the contact glass of the original mounting table 1 and the original (O) is not received by the pressure plate 8 and the external light, the time changes as shown in FIG. The on the contact glass of the document table 1 original (O) only, without the other reflected light is detected signal only to said light receiver A3c ₁ because there is not detected in the light receiving unit B3c _2. here,
“(The light receiver A3c ₁ ) − (the light receiver B3c ₂ )”
Is calculated, it is detected that the edge of the document (O) exists at a position exceeding the threshold level.

Further, when the pressure plate 8 and the external light are received on the contact glass of the document placing table 1, the time changes as shown in FIG. In the case of external light and the pressure plate 8,
“(The light receiver A3c ₁ ) − (the light receiver B3c ₂ )”
Does not exceed the threshold level, and erroneous detection by outside light and the pressure plate 8 can be prevented.

Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, a document for reading the document image by detecting the presence or absence of the document (O) placed on the document table 1 without erroneous detection. It has become possible to provide an image reading device.

[0079] In FIG. 5, so as to comprise a light splitting function by placing a partially transmitting mirror 3b ₂ to the position of the mask A3b ₁₁ of the optical splitting means 3b, was able to simplify the apparatus.

[0080] The said partially transmitting mirror 3b ₂ mask A
3b ₁₁ to serve the same function as, the light receiver A3
One of c ₁ and the light receiver B3c _2, for example, the light receiver A3c ₁ only signal is detected, the image of the reflected light from the distance of the original (O) to the light receiver B3c ₂ are all transmitted, the other It has a shape which reflects only light other than the distance of the original (O) to the light receiver B3c _2.

Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, the presence or absence of the document (O) placed on the document table 1 is detected without erroneous detection to read the document image. It is possible to provide a low cost and high maintenance document image reading apparatus with a small number of parts.

[0082] In FIG. 6, so as to comprise a light splitting function by placing a partially reflecting mirror 3b ₃ to the position of the mask A3b ₁₁ of the optical splitting means 3b, was able to simplify the apparatus.

The partial reflection mirror 3b _{3 is connected} to the mask A
3b ₁₁ to serve the same function as, the light receiver A3
One of c ₁ and the light receiver B3c _2, for example, the light receiver A3c ₂ only signal is detected, the image of the reflected light from the distance of the original (O) to the light receiver B3c ₂ are all reflective, the other has a shape that transmits only light other than the distance of the original (O) to the light receiver B3c _1.

Accordingly, even if there is disturbance light such as illumination of a fluorescent lamp, the presence or absence of the original (O) placed on the original table 1 is detected without erroneous detection to read the original image. It is possible to provide a low cost and high maintenance document image reading apparatus with a small number of parts.

In FIGS. 7 and 8, the light splitting means 3b
Wedge 3b ₄ open holes at the position of the mask _{A3b 11}
The arranged with the light splitting function, the light receiver 3 of the light receiver A3c ₁ and region 2, as shown the light receiver B3c ₂
By using the split photodiode, the device could be further simplified.

The aperture wedge 3b ₄ has an opening that transmits the reflected light of the original (O) and polarizes the reflected light other than the reflected light of the original (O) so as to fulfill the same function as the mask A3b _11. 3b ₄₁ .

The opening 3b ₄₁ of the perforated wedge 3b ₄ does not need to have the shape of the reflected light of the original (O) completely as shown in the figure. .

Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, the presence or absence of the document (O) placed on the document table 1 is detected without erroneous detection to read the document image. It is possible to provide a low cost and high maintenance document image reading apparatus with a small number of parts.

[0089] In FIG. 9, includes a light splitting function by arranging a partial wedge 3b ₅ to the position of the mask _{A3b 11} of the optical splitting means 3b, the light receiver of the light receiver 3 A3c
As used area bisected photodiodes in use thereof shown in ₁ and the light receiver B3c _2, further we were able to simplify the apparatus.

[0090] the partial wedge 3b ₅ is, the mask A
3b ₁₁ to serve the same function as the reflected light of the original (O) is polarized, light other than the reflected light of the original (O) has a partial wedge such that transmission.

Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, the presence or absence of the document (O) placed on the document table 1 is detected without erroneous detection to read the document image. It is possible to provide a low cost and high maintenance document image reading apparatus with a small number of parts.

[0092] In FIG. 10, comprises a light splitting function by arranging a partial analysis grid 3b ₆ to the position of the mask _{A3b 11} of the optical splitting means 3b, the light receiver of the light receiver 3 A3
The c ₁ and the light receiver B3c ₂ so as to use the region 2 divided photodiode as shown, further, were able to simplify the apparatus.

The partial analysis grid 3b ₆ is formed by the mask A
In order to fulfill the same function as 3b ₁₁ , the reflected light of the document (O) is polarized, and the reflected light of the document (O) is transmitted, except for the reflected light of the document (O). It has a partial diffraction grating shaped to polarize light other than the reflected light of the original (O).

[0094] The partial analysis grid 3b ₆ are relief type,
Any material may be used as long as it is formed in a region required by a commonly used diffraction grating such as a volume type.

[0095] The position disposed above partial analysis grid 3b ₆ is not necessarily placed perpendicular to the incident light, for example, it may be placed to be inclined high diffraction efficiency direction. Furthermore,
It is also effective to use a blazed or reflective type for high efficiency.

Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, the presence or absence of the document (O) placed on the document table 1 is detected without erroneous detection to read the document image. It is possible to provide a low cost and high maintenance document image reading apparatus with a small number of parts.

In FIG. 11, the light receiving area dividing means 3b ₇
Represents the light receiver 3 itself as shown in FIG.
₁ and region 2 split photodiode of the optical receiver B3c _2, disposed at the image position of the reflected light from the original (O), the imaging geometry of the imaging geometry or approximation of the reflected light from the original (O) And the surrounding area, the light dividing means 3b
Has the same light splitting function when the half mirror 3b ₁ and the mask _{A3b 11} and made of the mask _{B3b 12} mag.

In FIG. 12, the light receiving area dividing means 3
b ₇ is a method of dividing the region 2 divided photodiode of the light receiver A3c ₁ and the light receiver B3c ₂ of the light receiving device 3, as shown, same shape as the image of the original (O) is preferable .

[0099] In FIG. 13, however, the light receiving region dividing means 3b ₇ is divided into three parts as the dividing method illustrated Segmentation photodiode between the light receiver A3c ₁ and the light receiver B3c ₂ of the light receiver 3 The shape described above is easy to produce, has high versatility, reduces costs, reduces the number of parts, and is advantageous for miniaturization.

Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, the presence or absence of the original (O) placed on the original table 1 is detected without erroneous detection to read the original image. It has become possible to provide a small-sized document image reading apparatus with a small number of parts and low cost and high maintenance.

In FIG. 14, diffraction of the scanning means 2b is performed.
Lattice 2b₁Is a disk-shaped hologram diffraction grating,
Irradiation light is obtained by rotating the drive means (not shown).
2b ₁₁To the mirror 2b₁₂More incident and polarized
And scan in a circle.

Therefore, since the light path length does not change when scanning the contact of the document table 1, the image formed on the document (O) at any position becomes constant, and erroneous detection is prevented. The result is that stable signal detection has become possible.

In FIG. 15, the pre-scanning means 2b
Zum 2b₂Is a rotatable micro prism,
Irradiation light is obtained by rotating the drive means (not shown).
2b ₂₁Incident, polarized, and scans in a circular fashion.
ing.

Accordingly, since the light path length does not change when scanning the contact glass of the document table 1, the image formed on the document (O) at any position becomes constant, and erroneous detection is performed. Prevention and stable signal detection became possible.

[0105]

According to the first aspect of the present invention, a scanning light for detecting the presence or absence of a document placed on a document table is projected. The reflected light beam having astigmatism from the projected original is divided by the light receiving device into components intersecting with each other, and the light beam shape of at least one of the components is regulated by the scanning light projecting device so as to be received. Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, a document image reading device that detects the presence or absence of a document placed on a platen and reads a document image without erroneous detection is provided. I can do it.

According to the second aspect of the present invention, the light is projected by the scanning light projecting means having the light condensing means for projecting the scanning light for detecting the presence / absence of the document placed on the document placing table. The reflected light beam having astigmatism from the document is divided into components in the direction intersecting by the light receiving unit, and the light beam shape of at least one of the components is regulated so as to be received. Even if there is, the light of the light source efficiently illuminates the original on the contact glass of the original placing table,
A document image reading apparatus that detects the presence or absence of a document placed on a document table without erroneous detection and reads a document image can be provided.

According to the third aspect of the present invention, the scanning means for projecting scanning light for detecting the presence / absence of a document placed on the document table is provided by the scanning light projecting means having a diffraction grating.
Since the reflected light flux having astigmatism from the projected document is divided into components in the direction intersecting by the light receiving means, the light flux shape of at least one of the components is regulated and received, so that the illumination of the fluorescent lamp is performed. Even when there is disturbance light, the image formed on the document at any position becomes constant, and it is possible to reliably prevent erroneous detection and detect the presence or absence of the document placed on the platen. It has become possible to provide a document image reading device for reading.

According to the fourth aspect of the present invention, the scanning means for projecting the scanning light for detecting the presence / absence of the document placed on the document placing table is provided by the scanning light projecting means having the prism.
Since the reflected light beam having astigmatism from the projected document is divided into components in the direction intersecting by the light receiving means, the light beam shape of at least one of the components is regulated and received, so that the illumination of the fluorescent lamp is performed. Even if there is disturbance light, the image formed on the document at any position will be constant, and erroneous detection will be reliably prevented to detect the presence or absence of the document placed on the platen. It has become possible to provide a document image reading device that reads a document.

According to the fifth aspect of the present invention, the scanning lens for projecting the scanning light for detecting the presence / absence of the original placed on the original placing table is used to scan the cylindrical lens from the projected original. As a result, the reflected light flux having astigmatism is divided into components in the direction intersecting by the light receiving means, and the light flux shape of at least one of the components is regulated so as to be received. However, it is possible to provide a document image reading apparatus that reads a document image that can easily detect the presence or absence of a document placed on a document table without erroneous detection. .

According to the sixth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the original placed on the original placing table is provided with the astigmatism from the projected original. Since the reflected luminous flux having the aberration is divided into components in the direction intersecting by the light dividing means of the light receiving means, the light flux shape of at least one of the components is regulated and received, so that disturbance light such as illumination of a fluorescent lamp may be generated. Even if a document image is read, it is possible to provide a document image reading apparatus that detects the presence or absence of a document placed on a document table and reads a document image without erroneous detection.

According to the seventh aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the original placed on the original placing table is provided with the astigmatism from the projected original. Since the reflected luminous flux having the aberration is divided into components in the direction intersecting by the half mirror of the light splitting means of the light receiving means, the luminous flux shape of at least one of the components is regulated so as to be received. It is possible to provide a document image reading apparatus that detects the presence or absence of a document placed on a document table and reads a document image without erroneous detection even when there is disturbance light.

According to the eighth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the document placed on the document placing table is provided with the astigmatism from the projected document. The reflected luminous flux having the aberration is divided into components in the direction intersecting by the light splitting means of the light receiving means, and the light flux shape of at least one of the components is regulated by the mask so that the light is received. Even if there is light, it is possible to provide a document image reading apparatus that detects the presence or absence of a document placed on a document table and reads a document image without erroneous detection.

According to the ninth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the original placed on the original placing table is provided with an astigmatism from the projected original. Since the reflected luminous flux having the aberration is divided into components in the direction intersecting by the partially transmitting mirror of the light splitting means of the light receiving means, the light flux shape of at least one of the components is regulated and received, so that the illumination of a fluorescent lamp, etc. Provided is a low-cost, high-maintenance document image reading device that detects the presence or absence of a document placed on a document table without erroneous detection even when there is disturbance light, and reads the document image with a small number of components. I can do it.

According to the tenth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the document placed on the document placing table is provided with the astigmatism from the projected document. Since the reflected luminous flux having the aberration is divided into components in directions intersecting by the partial reflection mirror of the light splitting means of the light receiving means, the light flux shape of at least one of the components is regulated and received, so that the illumination of a fluorescent lamp, etc. Provided is a low-cost, high-maintenance document image reading device that detects the presence or absence of a document placed on a document table without erroneous detection even when there is disturbance light, and reads the document image with a small number of components. I can do it.

According to the eleventh aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the original placed on the original placing table is provided with the astigmatism from the projected original. Since the reflected luminous flux having an aberration is divided into components in the direction intersecting with the perforated wedge of the light splitting means of the light receiving means, the luminous flux shape of at least one of the components is regulated and received, so that illumination of a fluorescent lamp or the like is performed. Provided is a low-cost, high-maintenance document image reading device that detects the presence or absence of a document placed on a document table without erroneous detection even when there is disturbance light, and reads the document image with a small number of components. I can do it.

According to the twelfth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the original placed on the original placing table is provided with an astigmatism from the projected original. Since the reflected luminous flux having the aberration is divided into components in the direction intersecting with the partial wedge of the light splitting means of the light receiving means, the light flux shape of at least one of the components is regulated so as to be received, so that illumination of a fluorescent lamp, etc. Provided is a low-cost, high-maintenance document image reading device with a small number of components for detecting the presence or absence of a document placed on a document table without erroneous detection even when there is disturbance light, and for reading a document image. Is now available.

According to the thirteenth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the original placed on the original placing table is provided with the astigmatism from the projected original. Since the reflected luminous flux having an aberration is divided into components in directions intersecting by the partial diffraction grating of the light splitting means of the light receiving means, the light flux shape of at least one of the components is regulated and received, so that illumination of a fluorescent lamp or the like is performed. Provided is a low-cost, high-maintenance document image reading device that detects the presence or absence of a document placed on a document table without erroneous detection even when there is disturbance light, and reads the document image with a small number of components. I can do it.

According to the fourteenth aspect of the present invention, the scanning light projecting means for projecting the scanning light for detecting the presence or absence of the document placed on the document placing table is provided with a non-point light from the projected document. The reflected light beam having the aberration is received by regulating the shape of the light beam of at least one of the components divided in the direction intersecting by the light receiving area dividing means for dividing the light receiving area of the light receiver of the light dividing means of the light receiving means. Therefore, even if there is disturbance light such as illumination of a fluorescent lamp, the number of parts for detecting the presence or absence of a document placed on the platen and reading the document image without erroneous detection is small, and low cost and high cost A small document image reading device can be provided by maintenance.

According to the fifteenth aspect, the scanning light projecting means for projecting the scanning light for detecting the presence / absence of the original placed on the original placing table is provided with an astigmatism from the projected original. The reflected light beam having the aberration is received by restricting the shape of the light beam of at least one of the components which are respectively divided into the components in the direction intersecting by the light receiving area dividing means for dividing the light receiving area of the light receiver of the light receiving means into three. As a result, even if there is disturbance light such as fluorescent light illumination, the number of components for detecting the presence or absence of a document placed on the platen and reading the document image without erroneous detection is small and versatile. It has become possible to provide a small original image reading apparatus with high cost, low cost and high maintenance.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically illustrating a document image reading apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a state of a main part of the document image reading apparatus according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a signal magnitude and time characteristic of a state of another main part of the document image reading apparatus according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating signal magnitude and time characteristics in other states of another main part of the document image reading apparatus according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating a main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 6 is an explanatory diagram illustrating a main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating a main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 8 is an enlarged explanatory view illustrating another main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating a main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 10 is an explanatory diagram illustrating a main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 11 is an explanatory diagram illustrating a main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 12 is an enlarged explanatory view illustrating another main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 13 is an enlarged explanatory view illustrating another main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 14 is a perspective view illustrating a main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 15 is a perspective view illustrating a main part of a document image reading apparatus according to another embodiment of the present invention.

FIG. 16 is an explanatory diagram illustrating an outline of a conventional document image reading apparatus.

FIG. 17 is an explanatory view schematically illustrating another document image reading apparatus according to the related art.

FIG. 18 is an explanatory diagram illustrating a state of a main part of another conventional document image reading apparatus.

FIG. 19 is an explanatory diagram illustrating characteristics of signal magnitude and time of another main part of another document image reading device of the related art.

FIG. 20 is an explanatory view schematically illustrating another document image reading apparatus of the related art.

FIG. 21 is an explanatory diagram illustrating a state of a main part of another document image reading apparatus of the related art.

FIG. 22 is an explanatory diagram illustrating characteristics of signal magnitude and time of another main part of another document image reading apparatus of the related art.

[Explanation of symbols]

0 Document Image Reading Device 1 Document Placement Table 2 Scanning Light Projecting Unit, 2a Condensing Unit, 2b Scanning Unit, 2b ₁ Diffraction Grating, 2b ₁₁ Irradiation Light, 2b ₁₂
Rising mirror, 2b ₂ prisms, 2b ₂₁ irradiation light, 2c light source, 2d light splitting means 3 light receiving means, 3a cylindrical lens, 3b light splitting means,
3b ₁ half mirror, 3b ₁₁ mask A, 3b
₁₂ masks B, 3b ₂ partially transmitting mirrors, 3b ₃
Partially reflective mirror, 3b _4- hole wedge, 3b ₄₁
Opening, 3b ₅ partial wedge, 3b ₆ partial analytical grid, 3b ₇ light receiving area dividing means, 3c light receiver, 3c ₁
Light receiver A, 3c ₂ Light receiver B, 3d Condensing lens 4 Illumination lamp 5 Mirror group 6 Lens 7 Light receiving element 8 Pressure plate 100 Original image reading device 101 Hologram scanner 102 Perforated mirror, 102a hole, 102b Mirror portion 103 Semiconductor laser 104 Photodetector 105 Contact glass 106 Pressure plate 200 Original image reading device 201 Light source 202 Light splitting element 203 Scanning mirror 204 Contact glass 205 Pressure plate 206 Light receiving lens 207 Cylindrical lens 208 Light receiving element 209 Fluorescent lamp

Continued on the front page F-term (reference) 2F065 AA03 AA22 AA23 AA31 BB01 BB24 CC02 DD12 FF44 GG02 GG06 GG07 HH04 JJ01 JJ15 JJ18 JJ23 LL08 LL12 LL37 LL46 MM26 QQ03 QQ04 QQ08 QQ25 2A01A062A012 CA09 CA14 DA02 DA05 DA10 DA20 DA21 DA23 HA02 HA10 LA02 RA02

Claims (15)

[Claims] A document image reading apparatus for detecting the presence or absence of a document placed on a document table and reading a document image, and a document table placed on the document table and a document placed on the document table. Scanning light projecting means for projecting scanning light for detecting the presence or absence of an original, and a reflected light beam having astigmatism from the document projected on the scanning light projecting means as a component in a direction intersecting. A document image reading apparatus, comprising: a light receiving unit that regulates and receives a light beam shape of at least one of the divided components. 2. An original image reading apparatus according to claim 1, wherein said scanning light projecting means comprises a condensing means. 3. An original image reading apparatus according to claim 1, wherein said scanning light projecting means includes a diffraction grating. 4. An original image reading apparatus according to claim 1, wherein said scanning light projecting means includes a prism. 5. An original image reading apparatus according to claim 1, wherein said light receiving means comprises a cylindrical lens. 6. A document image reading apparatus according to claim 1, wherein said light receiving means comprises light splitting means for splitting the reflected light flux into components in a direction intersecting each other. Document image reading device. 7. An original image reading apparatus according to claim 1, wherein said light splitting means comprises a half mirror. 8. A document image reading apparatus according to claim 1, wherein said light receiving means is adapted to apply a reflected light flux having astigmatism from the document to a component in a direction crossing said reflected light flux. An original image reading apparatus comprising a mask for regulating a light flux shape of at least one of the divided components. 9. An original image reading apparatus according to claim 1, wherein said light splitting means comprises a partially transmitting mirror. 10. A document image reading apparatus according to claim 1, wherein said light splitting means comprises a partial reflection mirror. 11. An original image reading apparatus according to claim 1, wherein said light splitting means comprises a perforated wedge. 12. The original image reading apparatus according to claim 1, wherein said light splitting means comprises a partial wedge. 13. An original image reading apparatus according to claim 1, wherein said light splitting means comprises a partial analysis grid. 14. A document image reading apparatus according to claim 1, wherein said light splitting means comprises a light receiving area dividing means for dividing a light receiving area of a light receiver. Document image reading device. 15. A document image reading apparatus according to claim 14, wherein the light receiving area dividing means sets the light receiving area of the light receiver to three.
A document image reading device characterized by being divided.