JPH1124185A - Original size detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive original size detecting device, with a reliable and simple constitution, capable of distinguishing an original pressing surface from a white original, even if this original pressing surface is white. SOLUTION: A structural material 9 having a white sheet stuck to a surface is attached to the surface coming into contact with a contact glass 2 of the original cover 4 and the white sheet is coated with transparent fluorescent paint fully or according to the size of an original. When the transparent fluorescent paint is irradiated with specific-wavelength infrared rays, the transparent fluorescent paint emits second-wavelength (a different wavelength) infrared rays. If an original 3 is not present, upon closing the original cover 4 and irradiating it with first-wavelength infrared rays from a light source 5, the transparent fluorescent paint of the white sheet is irradiated with the first-wavelength infrared rays, to emit the second-wavelength infrared rays. If the original 3 is present, the first-wavelength infrared rays are reflected by the original surface without reaching the transparent fluorescent paint, that is, reflected in the same wavelength state. When the filter 7 of a detector 8 transmits only the second-wavelength infrared rays, the presence of the original can be detected by a place irradiated from the light source 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document size detecting device in a document reading device capable of using various document sizes.

[0002]

2. Description of the Related Art Document size detection in a document reading apparatus capable of using various document sizes is disclosed in
As disclosed in Japanese Patent Application Laid-Open No. 5-93161, a method of providing a transparent electrode on a document table, forming a document holder with conductive rubber, and detecting a document size based on a conduction state,
As disclosed in Japanese Patent Publication No. 1552, a method of providing a conductor on one of a platen and a pressure plate and a resistor on the other, and detecting the document size by changing the resistance value according to the document size.
A method of detecting the size of a document based on a pressure difference caused by the presence or absence of a document, as disclosed in Japanese Patent Application Laid-Open No. 0-140949; For detecting a document size by a change in capacitance caused by the
As disclosed in Japanese Patent Application Laid-Open No. 1-285442, various methods have been proposed so far, such as a method of applying a high voltage between a document table and a pressure plate and detecting a document size by a change in potential depending on the presence or absence of a document.

[0003]

Among these conventional methods and apparatuses, the use of a pressure plate having a white original pressing portion is used to irradiate light from below, and the presence or absence of the reflected light is used to detect the presence or absence of the original. In such a system, there is a problem that the same white original and the pressure plate cannot be distinguished. Therefore, in order to distinguish this, electrodes are provided on the pressure plate and glass,
A method for detecting the presence or absence of a document, a method for similarly detecting the position of the document by providing electrodes and resistors, a method using the change in pressure between the pressure plate and the glass due to the thickness of the document, The method using the change in the capacitance between the plates, the method using the change in the potential generated on the platen, the method of coloring the platen to distinguish it from the white of the document, and the situation of the reflected light before and after opening and closing the platen There is known a method for distinguishing the white color of the pressure plate from the white color of the pressure plate.

However, the provision of electrodes on the transparent glass on which the original is to be placed causes optical distortion, albeit slightly, and requires the provision of electrodes or resistors on the pressure plate, making the structure of the apparatus complicated and expensive. There is a problem of becoming. Further, the change in pressure, the change in capacitance, and the change in potential are small due to the presence or absence of a document in a thin document or the like, and there is a problem that the structure is complicated and expensive to obtain a desired detection accuracy. Further, if the press plate is colored, there is a problem that a dirty image is read out of the original, and an open / close detection switch is required to detect the open / close of the press plate, so that the configuration becomes complicated and expensive. .

Conventionally, there is also known an apparatus in which a plurality of electrodes and sensors are provided and a document size is detected by an ON / OFF pattern thereof. However, in such an apparatus, the electrodes or sensors are complicated and expensive. In addition, wiring from the electrodes or sensors to the control unit is required, and there is a problem that a complicated and expensive document size detection device is required. In addition, there is a limit to the places where the electrodes and sensors can be installed, and there is a problem that an erroneous detection is made when the position where the document is placed is shifted.

The present invention has been made in view of the above-mentioned various problems, so that even if the surface of the pressure plate against which the original is pressed is white, it can be distinguished from the white original, and can be reliably and securely used without using a detection mechanism having a complicated structure. An object of the present invention is to provide an inexpensive document size detecting device with a simple configuration.

[0007]

According to a first aspect of the present invention, there is provided an original size detecting apparatus for detecting an original in an original reading apparatus capable of using various types of original sizes. A transparent glass to be placed, a pressure plate coated with a transparent fluorescent paint that emits light of a second wavelength on a white surface that holds an original, and a light of a first wavelength disposed on the other side of the transparent glass is irradiated to the pressure plate side. Means, means for detecting reflected light of the second wavelength light, means for detecting the presence or absence of a document on the transparent glass by the amount of reflected light of the second wavelength light, and document output based on the output of the detection means It is characterized by having means for detecting the size.

According to a second aspect of the present invention, in order to achieve the above object, in a document reading apparatus or the like which can use various kinds of document sizes, a transparent glass on which a document is placed, and a white original fixed size document holding a document. A pressure plate that has a barcode display corresponding to the size of the original document made of a transparent fluorescent paint that emits light of a second wavelength in the vicinity of the outside; and a light plate of the first wavelength disposed on the other side of the transparent glass. Means for scanning and irradiating the side, means for detecting the reflected light of the second wavelength light, means for reading the bar code display from the reflected light of the second wavelength light, output of the bar code display reading means And means for detecting the size of the original.

According to a third aspect of the present invention, in order to achieve the above object, in a document reading apparatus or the like which can use various types of document sizes, a transparent glass on which a document is placed and a second wavelength on a white surface for pressing the document are provided. A pressure plate that draws a bar-like display at constant or specific intervals with a transparent fluorescent paint that emits light of
Means for scanning and irradiating the pressure plate side with light of the first wavelength disposed on the other side of the transparent glass, means for detecting reflected light of the light of the second wavelength, and reading the bar-shaped display from a start position And means for detecting the document size and position from the number of bar-shaped displays until the bar-shaped display disappears.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part of an image reading apparatus using an embodiment of a document size detecting apparatus according to the present invention. This image reading device includes a contact glass 2 made of transparent glass on a device main body 1, a pressure plate 4 for pressing an original 3 on the contact glass 2, and the like, and the configuration itself is well known.

In the present apparatus, the original 3 is placed on the contact glass 2, and the contact glass 2 is
It is pressed and fixed on the upper surface of. A light source 5 and a detector 8 including a light receiving unit 6 and a filter 7 are provided below the contact glass 2 so that an image of the original 3 is optically read.

A structural member 9 having a white sheet adhered to the surface of a sponge is attached to the surface of the pressure plate 4 which is in contact with the contact glass 2 so that the pressure plate 4 can be in close contact with the contact glass 2 outside the document 3. The white sheet is used to make the image formed on the outside of the document 3 white, thereby preventing useless images. Although this structure itself is well known, in the present embodiment, a transparent fluorescent paint (for example, an infrared light emitting phosphor of Hitachi Maxell, Ltd.) is applied to the white sheet of the structural material 9 over the entire surface or according to a prescribed original size. I have. This transparent fluorescent paint emits infrared light of a different wavelength ν2 when irradiated with infrared light of a specific wavelength ν1 (this feature is similar to a phosphor for a cathode ray tube of a color television). Note that a transparent fluorescent paint that has durability against ultraviolet rays, chemicals, and the like may be used.

That is, when the platen 4 is closed and infrared light of the first wavelength ν1 is irradiated from the light source 5 toward the platen 4, if there is no original 3, the white sheet of the structural material 9 is coated. The obtained transparent fluorescent paint is irradiated with infrared light of the first wavelength ν1, thereby emitting infrared light of the second wavelength ν2. If the original 3 is present, the first infrared light cannot reach the transparent fluorescent paint, and is reflected on the original surface to reflect the light of the wavelength ν1 as it is.

The filter 7 of the detector 8 has a second wavelength ν
Since only the infrared light is transmitted through the detector 8 and the detector 8 is sensitive only to this wavelength ν2, it is possible to detect the presence or absence of a document at that location. In other words, the white color of the original 3 and the white color of the pressure plate can be reliably distinguished.

FIG. 2 is a circuit diagram showing an electrical configuration of the light source 5 and the detector 8. Power supply 10 (5V) with current limiting resistor 1
1, infrared light emitting diode 12 (light source 5) and switch 1
3 in series. When the switch 13 is closed, a current flows through the infrared light emitting diode 12, and the infrared light emitting diode 12 emits infrared light having the wavelength ν2. Here, the switch 13 performs ON / OFF control using control means such as a microcomputer 16 provided in the image reading apparatus. The power supply 10 is connected to a series circuit of a current limiting resistor 14 and a phototransistor 15 (filter 7). The contact between the resistor 14 and the phototransistor 15
Connect to input of microcomputer 16. Since the phototransistor 15 has a filter on the light receiving surface that transmits only the wavelength ν1, the phototransistor 15 is turned on when receiving the light of the wavelength ν1.
(About 0.7 V), it is determined that there is no original 3 on the contact glass 2. The light source 5 and the detector 8 are installed at
The position is exactly the same as that of a conventionally known document size detecting device, and the method of determining the document size from the presence or absence of a document at that position is exactly the same as the conventional method.

FIG. 3 is a conceptual diagram showing an example of document size detection in another embodiment of the present invention. In the present embodiment, a structural member attached to a pressure plate 4 is configured such that a unit 20 including a light source that emits infrared light of a first wavelength and a detector that detects only a second wavelength can be moved left and right in the figure by a guide 21. The barcodes 22, 23, and 24 are drawn on a white sheet 9 with a transparent fluorescent paint to detect the document size. Note that the barcodes 22, 23, 24
Is enlarged for the sake of explanation, and is made smaller so as not to actually interfere with image reading. The dotted lines and characters in the figure are B5 size, A
The sizes of the fixed size originals of the 4 size, B4 size, and A3 size are shown for explanation, and are not actually drawn. The positions of the barcodes 22, 23 and 24 are drawn immediately outside the respective sizes.

Here, when the unit 20 is moved right and left in the figure by the guide 21 to read the barcodes 22, 23 and 24, for example, if all the barcodes are read, the document size is B5, and if only the barcode 24 is read, the document size is B5. Can be determined as B4 and so on. Since the barcodes 22, 23 and 24 are drawn with transparent fluorescent paint, they do not affect the image outside the document at all. In addition, barcodes 22, 23,
The reading means 24 can be replaced by conventional techniques such as scanning a light source with a rotating mirror and receiving the reflected light through a lens with a detector.

FIG. 4 is a conceptual diagram showing an example of document size detection in an apparatus according to still another embodiment of the present invention. This embodiment has a configuration similar to that of the embodiment apparatus of FIG. 3, except that bars 2 are drawn at regular intervals with a transparent fluorescent paint instead of a bar code.
5, 26 are used. The bar 26 indicating the starting point is drawn on the white sheet surface of the structural material 9 of the pressure plate 4. Since these bars 25 and 26 are drawn with a transparent fluorescent paint, they do not affect the image outside the document at all.

Therefore, similarly to the previous embodiment, the unit 20
Is moved from the right end to the left end in the figure, first, the bar 26 indicating the start point is read, and it is confirmed that the bar 26 has started correctly. This makes it possible to detect an abnormality when the unit 20 fails and starts reading without moving to the start point. Of course, the bar 26 indicating the start point need not be provided for the case where such an abnormality does not occur depending on the bar reading method. Next, unit 20 is bar 2
5 are detected one after another and the number is read. For example, in this example, if six bars are detected, it can be determined that the document is B5 size.

The bars need not always be at equal intervals, but may be close to each other in the vicinity of a standard document size so that a slight displacement of the document can be detected. Further, it is also possible to provide a structure in which bars are densely provided as a whole to accurately detect the position where the document is placed. Also, in the figure, the original is placed on the basis of the left end. However, when the original is placed at an arbitrary position, bars are provided at intervals of, for example, 1 mm, the bar is read from one end, and the bar is detected for a predetermined time. The position where the document is placed and the size of the document can be read from the number of bars until the bar disappears and the number of bars detected until the other end of the bar is detected. Note that the present embodiment can also be used for measuring the size of an object placed on the contact glass 2. However, in such an application, it is not always necessary to draw the bar with the transparent fluorescent paint.

[0021]

As described above, the document size detecting device according to the first aspect emits light having a wavelength different from the wavelength irradiated with the fluorescent paint even if the color of the pressure plate is white.
The light reflected from the original as it is and the light generated from the transparent fluorescent paint applied to the pressure plate can be reliably distinguished, the image outside the original can be completely read as white, and the transparent fluorescent paint is painted on the pressure plate side. It does not cause any distortion in the read image of the original, and can read even if the pressure plate is dirty, so that it can be inexpensive with a simple configuration without using a complicated detection mechanism. This has the effect.

According to the second aspect of the present invention, as described above, the position can be directly read from the bar code printed on the outside of the original on the pressure plate. The detector only needs to read the barcode, and there is an effect that the position control of the detector itself is unnecessary.

Since the document size detecting device according to the third aspect merely reads the number of bars applied to the pressure plate as described above, it is necessary to keep the scanning speed of the detector constant in addition to the common effect. The pressure plate can be constructed at low cost because there is no need for precision in the bar interval, bar width, etc. It is possible to read, and it is possible to determine a bar indicating the start point or the end point and detect an abnormality when a failure occurs in the detector.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an image reading apparatus using an embodiment of a document size detecting apparatus according to the present invention.

FIG. 2 is a circuit diagram showing an electrical configuration of a light source and a detector used in the embodiment of FIG.

FIG. 3 is a conceptual diagram illustrating an example of document size detection in another embodiment of the present invention.

FIG. 4 is a conceptual diagram showing an example of document size detection in a still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device main body 2 Contact glass 3 Document 4 Pressure plate 5 Light source 6 Light-receiving part 7 Filter 8 Detector 9 Structural material with white sheet adhered 10 Power supply 11 Current limiting resistor 12 Infrared light emitting diode 13 Switch 16 Microcomputer 14 Current limiting resistor 15 Photo Transistor 20 Unit 21 Guide 22, 23, 24 Barcode 25, 26 Bar

Claims (3)

[Claims] 1. A document reading apparatus or the like which can use various kinds of document sizes, a transparent glass on which a document is placed, a pressure plate coated with a transparent fluorescent paint which emits light of a second wavelength on a white surface for holding the document, Means for irradiating the platen side with light of the first wavelength disposed on the other side of the glass, means for detecting reflected light of the light of the second wavelength, amount of reflected light of the light of the second wavelength And a means for detecting the presence or absence of a document on the transparent glass, and a means for detecting the size of the document based on the output of the detection means. 2. An original reading apparatus which can use various kinds of original sizes, a transparent glass on which an original is placed, and a transparent fluorescent paint which emits light of a second wavelength immediately outside the fixed original size having a white surface for holding the original. A platen for producing a barcode display corresponding to the size of the original, a means for scanning and irradiating light of a first wavelength disposed on the other side of the transparent glass to the platen, and a light of the second wavelength. A document comprising: means for detecting reflected light; means for reading the bar code display from the reflected light of the second wavelength light; and means for detecting the size of the document based on the output of the means for reading the bar code display. Size detection device. 3. A document reading apparatus or the like which can use various types of document sizes, wherein a transparent glass on which the document is placed, and a transparent fluorescent paint which emits light of a second wavelength on a white surface for holding the document at regular or specific intervals. A pressure plate depicting a bar-shaped display, a means for scanning and irradiating light of a first wavelength disposed on the other side of the transparent glass to the pressure plate side, a means for detecting reflected light of the light of the second wavelength, start A document size detecting device, comprising: means for detecting the size and position of the document from the number of bar displays from the time when the bar display is read from the position until the bar display disappears.