JPS58173734A - Detecting device of size of original in copying machine - Google Patents

Abstract

PURPOSE:To execute copying of a good quality, by setting so that a main area of optical wavelength of a detecting means is not overlapped on a main area of optical wavelength of a copying optical system, and easily discriminating between a platen cover and an original. CONSTITUTION:In a platen cover 13, a plate-like infrared cut filter 19 is placed so that its one surface is exposed, so as to contain a reflecting point of light of light emitting elements P1-P3. Also, on one corner part which is made to press- contact with a guide 18, in the platen cover 13, a magnet of suitable size is embedded. Also, on a suitable position in a body 10, which is opposed to a magnet 20 in case when the platen cover 13 is closed, and also is capable of detecting a magnetic flux of the magnet 20, a proximity switch S constituted of a lead switch, etc. is provided, by which a detecting part for detecting the opening or closing state of the platen cover 13 is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects the size of the original to be copied, and selects the paper to be supplied or the scanning length of the copying optical system to be optimal for the size of the original. The present invention relates to a document size detection device (hereinafter simply referred to as "document detection device") for a copying machine.

As a conventional document detection device, as shown in FIG. 1 or FIG. 2 viewed from arrow 2 in this figure, appropriate detection means Dl to D3 are provided within a platen cover 91. 1 and 2, a platen 92 on which a document PA is placed is provided at the top of a main body 90 of the copying machine, and switch knobs 93A to 9 are provided in front of the main body 90.
During operation 93 with 3C is provided. Four sizes are set on the platen 92,
The size of the part surrounded by points Q-AI-A2-A4 is A1, and the size of the part surrounded by points Q-B1-B2-B3-B4 is B. The same applies to sizes 0 and D. This size A is usually Japanese Industrial Standard A.
This is set to the size of row 3 or 4, and row B, row 4 or 5.

On the other hand, on the side surface of the main body 90, there is a case 94 storing sheets of paper of sizes corresponding to the sizes A to D, respectively;
The copied paper (hereinafter referred to as "1 copy") is sent out,
Each tray 95 is provided with a tray 95 to be placed thereon.

Furthermore, light emitting elements El to E3 are provided at appropriate positions below the platen 92 in the main body 90, corresponding to the detection means D1 to D3, which are light receiving elements. That is, when the original PA is placed on the platen 92 and the platen cover 91 is closed, the detection means D1 is in the area of size B excluding the area of size A, and the area of size B in the area of size C is
The detection means D2 is located in the area excluding the area of size D, and the detection means D3 is located in the area of size D excluding the area of size C, facing each of the light emitting elements E1 to E3.

In the conventional apparatus having the above configuration, when a document PA of size C, for example, is placed on the platen 92 and the platen cover 91 is closed to make a copy, the detection means Dl to D3 are In ()2, the original PA blocks the light from the light-emitting elements F1 and E2, and only the light-emitting element D3 receives the light from the light-emitting element E3. (In other words, when the document PA is size A, the detection means D1 to D3 are detected, and when the document PA is size B, the detection means D2 are detected.
And D3, in the case of size C, light enters only D3, and in the case of size D, all detection means D1no! , D3, no light is incident. Therefore, the size of the original PA can be determined from the states of the detection means Dl to D3, and based on the result, paper feeding control or optical system scanning 1111 can be performed.
11 is performed by means not shown.

However, in such a conventional apparatus, when copying is performed with the platen cover 91 completely closed, the detection means Dl to 03 sizes are superimposed on any one of the sizes 8 to 03. When copying a document such as the above, the images of the detection means Dl to D3 will appear on the copy, making it impossible to make a high-quality copy.

In addition, in order to eliminate this inconvenience, as shown in FIG. 3, the detection means Dl to D3 are arranged inside the main body 90 of the copying machine, and the reflection of light by the document PA placed on the platen 92 is utilized. Although it is possible that the platen cover 91
Since the surface that contacts the original PA is usually white to prevent fogging, it is inconvenient that it is not possible to distinguish between the reflection from the original PA and the reflection from that surface of the platen cover 91, making it unsuitable for practical use. It's something that doesn't exist.

The present invention has been made in view of the above-mentioned circumstances, and eliminates the drawbacks of the prior art, prevents the image of the detection means from appearing on the copy sheet, and makes it possible to easily distinguish between the platen cover and the original, thereby achieving high quality. The object of the present invention is to provide a document detection device capable of making a copy, and further extending the life of the detection means, reducing the power required for the detection operation, and reducing the influence of ambient light on the detection operation. shall be.

That is, in this invention, the detection means is housed in the main body of the copying machine, the light wavelength of the detection means is set to a value different from the light wavelength used for copy scanning, and the light of the detection means is placed on the platen cover. A device that uses an absorbing member to detect the open/closed state of the platen cover and detect the size of the document when the platen cover is closed, thereby making it possible to accurately detect the document size. It is.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The document detection device according to the present invention will be described in detail below according to embodiments shown in the drawings.

FIG. 4 is a perspective view showing an example of a copying machine equipped with the document detection device according to the present invention, and FIG. 5 is a partially cross-sectional view showing the arrangement of the document detection device with the platen cover closed. This is an explanatory diagram and is seen from arrow V in FIG. 4.

Further, FIG. 6 is an explanatory view corresponding to FIG. 5 showing a state in which there is no document PA, and further, FIG. 7 shows a state in which FIG. 6 is viewed in the direction of the arrow 2 in FIG. 4.

In these FIGS. 4 to 7, the main body 10 of the copying machine
The upper table 11 is provided with a platen 12 on which a document PA is placed approximately in the center thereof, and specifically, the document PA is placed on a platen glass 12G. On this platen 12, similarly to FIG. 1, areas of sizes A to A are numbered. Furthermore, a registration guide (hereinafter simply referred to as "guide 1") 18 is provided along the platen 12 at one end of the table 11, and the platen cover 13 is parallel to this guide 18 with the platen 12 in between. A support mechanism 14 is provided at the other end. The platen cover 13 is a support member 13
A and 13B are rotatably supported by the support mechanism 14 in the h direction of the arrow F1 in FIG. 4, and in the completely closed state, as shown in FIG. It has a shape so large that it even covers the surface of the sun.

Next, an operation panel 15 is provided on the front-F section slope parallel to the guide 18 of the main body 10, and includes items 15A to 15B necessary for operating switches and the like (hereinafter simply referred to as "switches 1"). Provided as appropriate. Further, on one side of the main body 10, there are provided a case 16 in which sheets h1 of sizes corresponding to the above-mentioned sizes A through H1 are stored, and a tray 17 on which copies are sent out and placed, as in FIG. ing.

On the other hand, inside the platen cover 13 is a plate-shaped infrared cut filter (hereinafter simply referred to as "filter 4") 19, the surface of which is exposed so as to include the light reflection points of light emitting elements P1 to P3, which will be described later. Further, the guides 1 to 1 of the platen cover 13 are arranged as shown in FIG.
A magnet 20 of an appropriate size is buried in one corner that comes into contact with the magnet 8. Furthermore, when the platen cover 13 is closed, a proximity switch S constituted by a reed switch or the like is provided at an appropriate position within the main body 10 that faces the magnet 20 and can detect the magnetic flux of the magnet 20. This constitutes a detection section that detects whether the platen cover 13 is open or closed.

Further, below the platen 12 and inside the main body 10, light receiving elements R1 to R3, which are detection means, are arranged, and the light emitted by the light emitting probes P1 to P3 is reflected on the original PA. It is designed to be incident. Behind this light reflection point, the light reflection point of the light emitting element P1 is located in the area of the size B excluding the size A area.
The light reflection point of light emitting element P3 is located in the area of size C excluding the area of size B.
The light emitting elements P1 to P3 are arranged so as to be present in the area excluding the area of size C among the areas.

In other words, the reflection points are arranged to correspond to the positions of the detection means [)1 to D3 in FIG. 1. Also,
When there is no document PΔ, the reflection point is configured to be within the exposed surface of the filter 19, and the back surface of the filter 19, that is, the joint surface 13G between the filter 19 and the platen cover 13 is normally It will be white like the platen cover surface.

Next, the filter 19 and the light emitting elements P1 to P3 described above are connected.
An example of the characteristics is shown in FIGS. 8 and 9.

First, the characteristics of the filter 19 are, as shown in FIG. 8, a wavelength of 400! Transmits light in the visible light range of 700ns,
Light is cut off in the infrared region with a wavelength of 700 rv or more. Next, as shown in FIG. 9, the characteristics of the light emitting elements P1 to P3 have a peak around the wavelength of 950n11;
The light cannot pass through the filter 19.

Next, FIG. 6 shows a configuration example of a determination circuit that determines the size of the document PA from the detection outputs of the light receiving elements R1 to R3, the light emitting elements P1 to P3, and the proximity switch described above. In this figure, the detection outputs of the light receiving elements R1 to R3 are as follows:
The signals are amplified by amplifiers 62A to 62G, respectively, and input to comparators 63A to 63G, respectively, where waveform shaping is performed so as to be suitable for logic operations to be described later. Further, the proximity switch S is input to AND gates 65A to 65D, respectively, and is input to a comparator 63A.
The output of is input to the AND guide 65A, and is also input to the AND gates 1-65B to 6 via the inverter 84A.
Each is input into 5D.

Also, the output of the comparator 63B is the AND gate 65△
and 65B, and is also input to AND gates 65G and 65D via an inverter 4B.The output of a comparator 63C is input to JAND gates 65A to 65C, and is also input to an AND gate 65D via an inverter 64G. has been entered. Further, the proximity switch S connects the light emitting elements Pl to P via the drive circuit 61.
3, respectively.

To explain the contents of the logic circuit of the IFi circuit configured as above, first, the proximity switch S outputs a logic value r only when it is in the closed state as shown in FIG.
)-IJ level. Next, the light-receiving element R1 outputs the level "((j) only in the case of an original of size A. Similarly, the output of the light-receiving element R2 becomes the level r LI J for originals of sizes A and B. , the light receiving element R3 outputs the rHJ level for documents of sizes A to C. Based on the above operations, the states of the outputs TA to TD of the determination circuit for documents of sizes A to D are shown in the table. and as follows. −m=− However,
rHJ, ``Ll'' represents a logical value, and the output of the proximity switch S is assumed to be at the ``T1'' level.

That is, the output of the proximity switch S is the AND gate 65A.
65D, the output shown in the above table is performed only when the output of the proximity switch S is at the rHJ level. Further, the drive circuit 61 operates only when the output of the proximity switch S is at the rHJ level, and the light emitting elements P17'J to P3 emit light. ” level, the outputs of the light receiving elements R1 to R3 are all r
It is LJ level. To put it bluntly, the determination circuit shown in FIG. 10, in addition to the conventional size determination shown in the table above, also functions as a drive unit that performs the size detection operation only in the closed state shown in FIG. are doing.

Next, the overall operation of the above embodiment will be explained with reference to FIGS. 4 to 11. Note that FIG. 11 is an explanatory diagram showing how the platen glass 12G1 original PA, filter 19, and platen cover 13 are superimposed, and how light travels.

First, the operator places the document PA on the platen 12 with the top 13 of the platen 12 opened as shown in FIG. In this state, since the proximity switch S is at 1 level, the outputs A to TD of the judgment circuit are all at the rLJ level, and the light emitting elements P1 to P3 are not energized and do not emit light.

Next, in order to make copies, the operator places the platen cover 1
3 as shown in FIG. Therefore, the proximity switch S changes from rLJ to [H level, and the light emitting elements P1 to P3 emit light by the drive circuit 61.

Here, assuming that the document PA is of size B, as shown in FIG. 5 or FIG. 11, the light emitting element P1
The light is reflected by the original PA as indicated by arrows L1 and 12 and enters the light receiving element R1. On the other hand, the light from the light emitting elements P2 and R3 reaches the filter 19 without being reflected by the original PA. As mentioned above, the filter 19 includes the light emitting element P2,
Since it has the characteristic of absorbing the light of R3 without transmitting it, the light of light emitting elements P2 and R3 travels as shown by arrow L3 and is absorbed by the filter 19, as shown in FIG. 6 or FIG. 11. It never reaches elements R2 and R3. Therefore, the meditation movement shown in the table above is performed by the judgment circuit, and the manuscript P
It is determined that the size of A is size B. Thereafter, based on the output of this judgment circuit, the paper feed size and the scanning distance of the optical system 50 (see FIG. 11) are selected in the same manner as in the prior art.

Below 1. After the operation, switch 15A is pressed by the operator.
Through the operations of 15G to 15G, the original @PA is copied in the same way as normal copying. At this time, the light emitted by the optical system 50 is
Although some wavelengths are absorbed by the filter 19, those in the visible light range are transmitted through the filter 19 as shown by arrow 14 in FIG. becomes. Therefore, the filter 19 has almost no effect on copying.

[In the above embodiment, the light receiving elements R1 to R3 and the light emitting elements P1 to P3 are used, but a reflective optical sensor may be used instead of these. In this way, the main body 10 can save space for a light emitting element or a light receiving element.

Furthermore, although the proximity switch S is used in the embodiment described above, the present invention is not necessarily limited to this, and other means may be used as long as the open/closed state of the platen cover 13 can be detected. Good too. For example, it may be detected from the rotation angle of a rotation shaft or the like within the support mechanism 14. Also, the judgment circuit lj” II.

If a timer device is provided in the drive circuit 61 and the light emitting elements P1 to P3 are made to emit light for a short time after the rHJ level signal is output from the proximity switch S, further power savings can be achieved. be able to.

As explained above, according to the document detecting device according to the present invention, all the size detecting devices are housed in the main body of the copying machine, and the wavelength range of the light used for this detecting means is used to scan the copy of the document. The wavelength range of the light is set to be different from that required for the detection means, and on the other hand, the platen cover is provided with an absorbing member that absorbs the light from the detection means, so that the image of the detection means does not appear on the copy or paper. In addition, it is possible to easily distinguish between the platen cover and the document, allowing for accurate detection of the document size.It also detects the opening/closing operation of the platen cover, and detects the document size when the platen cover is closed. Since this operation is performed, it is possible to reduce the power required for detection or extend the life of the detection means, and furthermore, it is possible to avoid the influence of ambient light on the detection operation, which is an excellent effect.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of a copying machine equipped with a conventional document detecting device, Fig. 2 is an explanatory diagram showing the arrangement of the document detecting device as seen from the arrow ■ in Fig. 1, Fig. 3, etc. FIG. 4 is a perspective view showing the external appearance of a copying machine equipped with a document detection device according to the present invention, and FIG. 5 shows the position of the document detection device as seen from arrow V in FIG. The explanatory diagram shown in Fig. 6 is the 5th
Among the figures, an explanatory diagram showing a state in which there is no document; FIG. 7 is an explanatory diagram showing the arrangement of the document detection device as seen from arrow v1 in FIG. 4;
Figure 8 is a diagram showing an example of the characteristics of an infrared cut filter.
FIG. 9 is a miniature diagram showing an example of light emitting characteristics of a light emitting element. FIG. 10 is a block diagram showing an example of characteristics of the judgment circuit.
FIG. 1 is an explanatory diagram showing how light travels and is reflected. 12... platen, 13... platen cover, 13
G... Joint surface, 19... Infrared cut filter which is an absorption member, 61... Drive unit, PA... Document, P
1 to R3...Light emitting elements, R1 to R3...Ukekukenshi, S...Proximity switch which is a detection section. −Distribution

Claims (1)

[Claims] A document size detection device for a copying machine, which includes a detection means arranged in the copying machine corresponding to the size of the document placed at a predetermined position on a platen to detect the size of the document,
The light wavelength main region of the detection means is set so as not to overlap with the light wavelength main region of the copying optical system, and a member that absorbs the light of the detection means is equipped in a portion where the light of the detection means is incident. A platen cover whose joint surface with this member is formed so as to reflect the light of the copying optical system, a detection section that detects the open/closed state of this platen cover, and a detection section that detects whether the platen cover is closed or closed based on the output of this detection section. A document size detecting device for a copying machine, comprising: a drive section that operates the detecting means when the detecting means is in the state.