JPH0470503A - Discriminating apparatus of size of paper etc. - Google Patents

Abstract

PURPOSE:To detect the size of a paper with high speed response and without using an upper lid, and to share an apparatus among series of papers of different size by obtaining a discriminatingng signal indicating the kind the paper in the series on the basis of the combination of detecting signals output form a photodetecting device. CONSTITUTION:Six beams are projected from a multi-beam light source 21, which form beam spots at positions Pa-Pf. These beam spots Pa-Pf are formed by an off-axis micro Fresnel lens array 25. The scattering and reflecting light from each of the beam spots Pa-Pf forms an image on the corresponding photodetector PDa-PDf by an image forming lens 22 and is detected by the photodetector PDa-Pf. The relation between the combination of binary signals and various kinds of the size of documents is obtained by discriminating the level of the detectingsignals of the photodetetors PDa-PDf with use of the respective suitable threshold values. Accordingly,it becomes possible to detect and further discriminate the size of documents of different series without an upper lid with high speed response.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION Technical Field The present invention is typified by a document size determining device used in a copying machine. The present invention relates to a device for determining the size of paper, etc.

Prior art and its problems Conventional document size determination devices installed in copying machines include a type that performs breath scanning using a photoelectric sensor as shown in Figure 16, and a type that uses a breath scan type that uses a photoelectric sensor as shown in Figure 17. There is a type that has a built-in proximity switch, etc.

In FIG. 16, a movable arm 53 is installed inside the copying machine 50.
is provided, and a large number of reflective photoelectric sensors 54 are attached to this arm 53. Movable arm 5 before copying operation
3 moves, the original on the glass plate 51 is scanned by the photoelectric sensor 54 (prescan), and the size of the original is determined based on the output signal of the photoelectric sensor 54 at this time. This type of device has the advantage of being able to discriminate between a wide variety of document sizes, but the presence of movable parts makes the entire device large and its mechanism complicated. Since pre-scanning is required, the time involved becomes loss time, and there is a problem that prompt copying cannot be performed.

In FIG. 17, a plurality of proximity switches 55 (for example, photomicro◆ sensors) 55 are built into the top cover 52 of a copying machine 50. As shown in FIG. A document is placed on the glass plate 51
52 is closed, each proximity switch 55 detects the presence or absence of a document at the location where the proximity switch is attached, and the document size is determined based on the detection signals of the plurality of proximity switches 55. This type has an advantage over the pre-scan type shown in FIG. 16 in that it can save space. However, since the sensor is located on the top lid, the document size cannot be determined without the top lid.
It cannot be applied to copiers with veFeed) function.
Even the slightest unevenness on the sensor will leave pressure marks on the document. If the size of the copy paper is larger than the size of the original, there may be problems such as the shadow of the sensor that is not hidden by the original appearing on the copy paper.

Furthermore, the original (paper) size used in copying machines is
In addition to the Japanese Industrial Standards A and B columns, which are the most common in Japan, there is also a series used in the United States that expresses sizes in inches. Since the paper sizes in these series are different, it is complicated to develop or manufacture a size discrimination device for each series.

SUMMARY OF THE INVENTION Purpose of the Invention The present invention provides a paper size discrimination device that is compact, has high-speed response, is capable of detection without a top cover, and can be shared among different paper size series. It is something.

Structure of the invention 2 Actions and effects A device for determining the size of paper, etc. according to the present invention is as follows.

This device can be used in common to determine the size of two different types of paper. These two series include a plurality of types of paper of different sizes and having approximately the same width and length. The paper size discrimination device according to the present invention uses a plurality of light beams such that the same discrimination signal can be obtained for two series of mutually corresponding sheets, and different discrimination signals can be obtained for different types of paper. a multi-beam light source projecting to different locations; a plurality of light receiving elements for respectively receiving the plurality of reflected light beams from the paper to be determined regarding the plurality of light beams; and the light receiving element corresponding to the plurality of reflected light beams. according to the series based on the combination of light receiving signals output from the two light receiving elements.

The present invention is characterized in that a discrimination signal indicating the type of paper is obtained.

The above two series include, for example, 2 Japanese Industrial Standards A and B series and the inch series with 1-inch specification.

According to this invention, a multi-beam light source, a plurality of light receiving elements, and an imaging optical system can be integrated, and furthermore, since there is no movable part, it is possible to achieve miniaturization. In addition, since the pre-scan operation is unscheduled, it has high-speed response. Furthermore, when the discrimination device of the present invention is applied to a copying machine, there is no need to provide it on the top cover, so paper size can be determined without a top cover, and it can also be applied to copying machines with automatic paper feeding function. While it is possible, there are still traces of oppression.

There are no problems with shadows appearing.

Further, according to the present invention, since it can be applied to both two different series of paper sizes, there is no need to prepare a discrimination device for each series.

The multi-beam light source may be configured from one light emitting element and an off-axis Fresnel lens array including a plurality of off-axis Fresnel lenses that divide the light emitted from the light emitting element into a plurality of parts and deflect them in different directions. can. With such a configuration, it is possible to downsize the multi-beam light source.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which the present invention is applied to a document size determining device used in a copying machine will be described in detail.

This example applies to 1 Japanese Industrial Standards Column A and B (hereinafter referred to as J
This invention relates to a document size discriminating device that is commonly used for discriminating the document size of the IS series (referred to as the IS series) and the document size displayed in units of inches used in the United States (hereinafter referred to as the 1 inch series).

In FIG. 1, a photosensor 20 for determining document size is placed at a suitable location inside a copying machine 10. As shown in FIG.

The top surface of the copying machine 10 is covered with a glass plate 11, and originals 1 to be copied of various sizes are placed at predetermined positions on the glass plate 11 (there are one side alignment and one center alignment as described later).
2 is placed. The photosensors 20 are arranged at different positions P 1 , P 2 , P 2 on the glass plate 11 where the original 12 is placed
A plurality of light beams (four in this example) are projected toward P and Pd, and the size of the original is determined by receiving the reflected light from the glass plate 11 or the original 12. Or output a detection signal for determination.

An example of the configuration of the document size determination photosensor 20 is shown in FIG. The photosensor 20 has a case 29,
In this case 29, a multi-beam light source 21, an imaging lens 22, and a light receiving element array 23 are arranged and fixed. The multi-beam light source 21 includes a light-emitting element, for example, a light-emitting diode 24 that generates light including infrared light, and two light-emitting diodes 24 placed above the light-emitting diode 24, which divide the output light into four light beams and collimate these light beams. It is composed of an off-axis φ micro Fresnel lens array 25 that projects to different positions at the top.

The light receiving element array 23 includes many light receiving elements.

In this embodiment, only four light receiving elements are used. Of course, it goes without saying that only the number of light receiving elements to be used may be arranged in the light receiving element array 23. Imaging lens 2
2, as will be described later, the projection light beam is mainly directed to the original 1.
The purpose is to image the diffusely reflected light (diffusely reflected light) from 2 on the corresponding light receiving element. Visible light cut filters 26 and 27 are provided on the upper surface of the case 29 above the multi-beam light source 21 and the imaging lens 22, respectively. In this embodiment, infrared light is used to determine the document size.

Off-axis micro Fresnel lens array 2
A configuration example of No. 5 is shown in FIG. This lens array 25 includes a plurality of (four in this embodiment) off-axis micro Fresnel lenses (hereinafter referred to as off-axis MF).
(abbreviated as L) 25a.

25b, 25c, and 25d are arranged in a predetermined arrangement. The off-axis MFL is as shown in FIG.

It has the function of deflecting the incident light beam in a desired direction according to the shape of the irregularly spaced gratings formed therein, and collimating the diffused light (also condensing the collimated light). Such off-axis MFLs 25a to 25d have a grating pattern in which a portion of a micro Fresnel lens is cut out. Using the off-axis MFL array 25 shown in FIG. 3, the light beams emitted from the two light emitting elements 24 are divided into four and collimated to form beam spots P, Pb, and Po.

Pd can be formed on the glass plate 11 at a position as shown in FIG.

FIGS. 4, 5, and 7 to 10 show the principle for determining the size of a single-sided type document using the photosensor 20 described above.

As described above, the spreading light emitted from one light-emitting element 24 is split into four light beams by the off-axis MFL array 25, collimated, and beam spots P-Pd of an appropriate area are delivered to the glass plate 11 or original 12. is irradiated.

The light irradiated onto the original 12 is diffusely reflected by the original 12, as shown in FIG. That is, manuscript 12
The brightness of the upper spot is almost constant from any direction. On the other hand, reflection on the front and back surfaces of the glass plate 11 is close to specular reflection, and as shown in FIG. 8, the component of reflected light (regularly reflected light) with a reflection angle α equal to the incident angle α becomes large. .

As shown in FIG. 5, the light receiving element array 23 is arranged at a position where it does not receive specularly reflected light from the glass surface 11. As a result, the photodetector array of 2304 photodetectors PD
-PDd can detect the diffused light from the original 12.

The imaging lens 22 focuses the weak diffused light from the original 12 into beam spots P, Pb, and Po.

The diffusely reflected light from P is transmitted to the corresponding light receiving elements PD, PDb, and PDo of the light receiving element array 23, respectively.

PD, functions to form an image on top.

In this embodiment, as shown in FIG.
are arranged along two predetermined adjacent sides of. This arrangement of originals is called one-sided alignment. Regarding JIS series manuscripts, as shown by the chain line in FIG. 9, B5. B5R,A
4. A4R.

Seven types of document sizes are determined: Folio, B4, and A3. B5R and A4R have the vertical and horizontal arrangement reversed from the other A4-A3. A folio has the same width as an A4 original and is slightly longer. Regarding the inch series originals, six types of original sizes are to be determined (the deviation is also inches as shown in FIG. 9). These JIS
As shown in a table in FIG. 10, originals of each size in the series and inch series correspond to those having approximately the same width and length. However, there is no size corresponding to B5R in the JIS series in the inch series.

In this example, there are four light beam spots P-P,
It is possible to discriminate between seven types of document sizes in the JIS series or six types in the inch series using the diffusely reflected light from. The multi-beam light source 21 is adjusted so that each beam spot P-Pd is formed at a position as shown in FIG. 9 in relation to the originals of each size.

FIG. 10 shows the relationship between the size of the placed document and the output of the light receiving elements PD-PDd that receive diffusely reflected light from the document. Photodetector PD.

The received light signals of ~PDd are level-discriminated using appropriate threshold values, and converted into binary signals of L level or H level. The L level represents a state in which a document is not detected, and the H level represents a state in which a document is detected. It is easy to understand that these document sizes are determined according to the combination of the levels of the output signals of the four light receiving elements PD to PDd. Document discrimination processing is performed by logic circuit or CPU
It can be done by A5 size and 5-×
For 8-size originals, the photodetector PD ~22
Although it is not possible to distinguish between the case where there is no original and the case where there is no original using only the output signal of a PD, since the cover of the copier cannot be closed when there is no original or the copy execution button is not pressed when there is no original, The A5 size can be determined in combination with the opening/closing detection signal or the press input signal of the copy execution button.

In this way, in this invention, it is possible to determine the original size of both the JIS series and the inch series using one type of photosensor 20, so this photosensor can also be used in a copying machine that uses JIS series paper. It can also be used in copying machines that use 2-inch series paper, and can also be used in copying machines that can use both JIS series and inch series paper.

The above-described off-axis MFL array 25 can be manufactured by various methods. for example.

A pattern of an off-axis MFL array is written on the electron beam resist using an electron beam writing method, and the electron beam resist is developed. Off-axis MFL array φ using the electron beam resist remaining film obtained in this way
A standby is created from the pattern by electroforming, transfer, etc. Using this stamper, it becomes possible to inexpensively reproduce a large number of off-axis MFL arrays by a resin molding method or the like.

As a projection lens for a multi-beam light source, not only an off-axis MFL array but also a plano-convex lens array or an aspherical lens array can be used. These lens arrays can be molded using a mold or the like.

FIGS. 11 to 15 show embodiments suitable for arranging original documents in combination with sensors. That is, all manuscripts are
The center line (a line passing through the center in the width direction) coincides with the center line CL of the glass plate 11, and one end of the document is placed at one end of the glass plate 11 so as to match the center line CL of the glass plate 11. In this embodiment, A5 is added as a JIS original size. A
There is no document size in the inch series that corresponds to the 5 sizes.

In this embodiment, six light beams are emitted from the multi-beam light source 21, and P and Pb are shown in FIG.

Bead c at the positions indicated by P , P , P and P
d e em spot is formed. An example of an off-axis MFL array 25 used to form these beam spots P-Pr is shown in FIG.

As can be seen from FIGS. 11 and 12.

These beams °spots P, Pb, Po, P
The diffusely reflected light from , P and Pf forms an image d
e lenses 22 to detect light receiving elements PD, PD, respectively.

An image is formed on PD, PD, PD and PDr, and the light is received by each of these light receiving elements.

FIG. 15 shows the relationship between the combinations of binary signals obtained by level-discriminating the light-receiving signals of the light-receiving elements PD to FD using appropriate threshold values and various document sizes. As a result, there are 8 types of 1 for the JIS series.
Regarding the inch series, it is possible to discriminate six types of document sizes.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing that a photosensor for determining document size is built into a copying machine. FIG. 2 is an enlarged perspective view, partially cut away, showing the configuration of a photosensor for determining document size. FIGS. 3 to 10 show an embodiment for determining the size of a single original. Figure 3 shows off-axis micro Fresnel lens.
FIG. 3 is a plan view showing the array. 4 and 5 show the configuration of the light projecting and receiving optical system, with FIG. 4 being a plan view and FIG. 5 being a side view. FIG. 6 is a perspective view showing the operation of an off-axis micro Fresnel lens. FIG. 7 is a diagram showing the state of diffuse reflection from the document surface, and FIG. 8 is a diagram showing the state of specular reflection from the glass surface. FIG. 9 is a diagram showing the relationship between the beam spot position and various document sizes. FIG. 10 shows the logic for determining the document size based on the output signal of the light receiving element. 11 to 15 show an embodiment for determining the size of a centered document. 11 and 12 show the structure of the light projecting and receiving optical system, with FIG. 11 being a plan view and FIG. 12 being a side view. FIG. 13 is a plan view showing an off-axis micro Fresnel lens array. FIG. 14 is a diagram showing the relationship between the beam spot position and various document sizes. FIG. 15 shows the logic for determining the document size based on the output signal of the light receiving element. FIGS. 16 and 17 are perspective views showing conventional examples. lO/copy machine. 11...Glass plate. 12...Manuscript. 20...Photo sensor for document size determination 21...Multi-beam light source. 22...Imaging lens. 23... Light receiving element array. 24...Light emitting element. 25...Off-axis micro Fresnel lens array. 25a-25f...Off-axis micro Fresnel lens. pp-pD, . . . light receiving element ap-Pr . . . projected light beam bow po-soto.

Claims (3)

[Claims] (1) A device that can be used in common to determine the size of two different series of paper, and these two series include multiple types of paper of different sizes with approximately the same width and length. A multi-beam light source that projects a plurality of light beams to different locations such that the same discrimination signal can be obtained for two series of mutually corresponding paper sheets and different discrimination signals can be obtained for different types of paper sheets, as described above. comprising a plurality of light receiving elements for respectively receiving a plurality of reflected light beams from the paper to be discriminated regarding the plurality of light beams, and an imaging optical system that guides the plurality of reflected light beams to the corresponding light receiving elements, A device for determining the size of paper, etc., which obtains a discrimination signal representing the type of paper according to a series based on a combination of light reception signals output from a light receiving element. (2) The apparatus for determining the size of paper or the like according to claim (1), wherein the two series are Japanese Industrial Standards A and B series and an inch series of inch specifications. (3) The multi-beam light source is composed of a light emitting element and an off-axis Fresnel lens array including a plurality of off-axis Fresnel lenses that divide the light emitted from the light emitting element into a plurality of parts and deflect them in different directions. The device for determining the size of paper, etc., according to claim (1) or (2).