JPH03250967A - Original reading device - Google Patents

Abstract

PURPOSE:To improve the operability by providing a 2nd lighting lamp lighting other side of an original to a side opposite to a photoelectric conversion element with the original inbetween and a means using the photoelectric conversion element to detect the luminous quantity from the 2nd lighting lamp transmitted through the original and identifying kinds of paper of the original based on a white level of the detection signal from the said photoelectric conversion element. CONSTITUTION:Kind of paper of an original is identified not by lighting a lighting lamp 1-1 in a CCD unit 1 but by lighting a transmission lamp 2-1 of a transmission unit 2. That is, a luminous quantity transmitted through an original (not shown) placed on a transparent original placing plate 3 such as a glass plate is detected by a CCD 1-d, and since the luminous quantity transmitted through the original different from the kind of the paper of the original (transmission original, reflection original and thin original), the king o the paper of the original is identified (identification of transmission original, reflection original and thin original) based on an output signal level of the CCD 1-4. Then the selection control of the read mode is implemented based on the result of identification of the hind of the original to execute the original read.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a document reading device that is capable of automatically identifying the paper type of a document and detecting double feeding of two or more documents. The purpose is to improve operability by making it possible to automate identification and double feed detection, etc.A photoelectric conversion element is provided on the opposite side of the photoelectric conversion element with the document in between to illuminate the back side of the document. At least one of the illumination lamps used for the reading unit is also used as that of a normal reading unit, and the amount of light from the illumination lamps that passes through the document is detected by the photoelectric conversion element to identify the paper type of the document; The configuration is configured to perform double feed detection for originals of more than one sheet.

[Industrial application field]

The present invention relates to a document reading device that can automatically identify the paper type of a document and detect so-called double feed of two or more documents.

In order to improve the operability and reduce the cost of a document reading device, it is strongly desired to automate the paper type identification of the document and to simplify the structure of the document double feed detection means.

[Conventional technology]

Generally, a reading unit (hereinafter referred to as a CCD unit) having an illumination lamp that illuminates the document surface and a photoelectric conversion element (hereinafter referred to as a CCD) for reading an image on the document surface is provided, and the CCD unit and the document are A document reading device is known that is configured to read images such as characters on the document surface by moving the document surface relatively. Paper types of the original include paper with low light transmittance and paper with high light transmittance, such as film originals (hereinafter referred to as transparent originals). Furthermore, even among the papers with low light transmittance, there are papers that hardly transmit light (hereinafter referred to as reflective originals) and papers that transmit a certain amount of light (hereinafter referred to as thin paper originals). 2. Description of the Related Art A document reading device with a transmission unit is known that can read either a reflective document or a thin paper document.

The above-mentioned document reading device with a transmission unit includes, in addition to an illumination lamp for reading the document, a transmission unit having a transmission lamp provided on the opposite side of the CCD unit across the document and irradiating the document from the back side. This is an original document reading device. If the paper type of the original is a transparent original, the illumination lamp is not turned on and only the transmission lamp is turned on to read the original, and in the case of a reflective original, the transmission lamp is not turned on and the original is read. The original is read with only the illumination lamp turned on, and in the case of a thin paper original, the original is read with both the transmission lamp and the illumination lamp turned on, for example. That is, it is necessary to control the lighting of the illumination lamp and transmission lamp in accordance with the paper type of the document. Conventionally, the lighting control of the illumination lamp and the transmission lamp has been manually performed by an operator to determine the paper type of the document and to control the control mode corresponding to each paper type.

Further, in a document reading device equipped with an automatic document feeder, it is necessary to prevent document reading errors due to double feeding of documents. Therefore, a document double feed detection means is provided to detect the occurrence of document double feed.

As shown in FIG. 9, the conventional double feed detection means includes a light emitting element 1o and a light receiving element 6 for double feed side output, facing each other with the original 5 in between, and detects the light transmittance of the original. By detecting this, it was possible to detect the occurrence of a double-feed state of a document fed from an automatic paper feeder (not shown). Note that the reference numeral 4 in FIG.
is a CCD unit and includes a reflecting mirror 4-2. Lens 4-3
It is composed of a CCD 4-4, 4-1 is an illumination lamp, and 7 is a document feed roller.

[Problem R to be Solved by the Invention] As explained above, the conventional transmissive unit is capable of reading a transmissive original, a reflective original, or a thin paper original, regardless of the paper type of the original. The original document reading device requires the operator to judge the paper type of the document and manually select a reading control mode corresponding to each paper type, which is a complicated operation.

In addition, the conventional double feed detection means shown in FIG. 9 requires a dedicated light emitting element and light receiving element for double feed detection, which not only complicates the configuration (and increases costs). There was an undesirable problem.

Furthermore, in order to automatically check the paper type of a document, a specially prepared photoelectric conversion element is required.

The present invention aims to solve the above-mentioned undesirable problem, and aims to improve operability by enabling automation of document paper type identification and double feed detection. do.

[Means for Solving the Problems] FIG. 1 is a diagram showing the principle configuration of a document reading device according to the present invention. The code 1 in the figure is a CCD unit, 1-1
is an illumination lamp, 1-2 is a reflecting mirror 1-3 is a lens, 1-4
is a CCD, 2 is a transmission unit, 2-1 is a transmission lamp, 2
-2 represents a transparent plate, and 3 represents a document placement plate.

The principle configuration diagram in Figure 1 shows a document reading device that aims to improve operability by automatically identifying the paper type of a document and controlling the selection of a reading mode corresponding to the paper type. A schematic diagram is shown.

In Figure 1, it goes without saying that the reading of the original is
This is carried out using the CD unit 1 and the transmission lamp 2-1, but in order to identify the paper type of the document prior to that, the illumination lamp 1-1 in the CCD unit 1 is not turned on, and the transmission lamp 2-1 in the transmission unit 2 is turned on. 1 is lit. That is, the CCD 1-4 detects the amount of light that passes through an original (not shown) placed on a transparent original placing plate 3 such as a glass plate, and detects the paper type of the original (transparent original, reflective original, thin paper). Since the amount of light that passes through the original differs depending on the original (original), the C
Identification of the paper type of the original based on the output signal level of CD1-4 (identification of transparent original, reflective original, or thin paper original)
will be held.

Next, based on the identification result of the paper type of the manuscript,
Reading mode selection control is performed and document reading is executed. In other words, ■ In the case of a reflective original, the transmission lamp 2-1 is not turned on, and the illumination lamp 1-1 is turned on.
only lights up.

■ For transparent originals, do not turn on illumination lamp 1-1, but turn on transmission lamp 2-1.
only lights up.

■ For thin paper originals, turn on both the illumination lamp 1-1 and the transmission lamp 2-1.

FIG. 2 is a diagram illustrating another basic configuration of the document reading device according to the present invention. The reference numeral 4 in the figure is a CCD unit, 4-
1 is an illumination lamp, and 4-2 is a reflecting mirror.

4-3 is a lens, 4-4 is a CCD, 5 is a light receiving element for the document 16, and 7 is a document feed roller.

The principle configuration diagram of FIG. 2 shows a schematic diagram of a document reading device equipped with document double feed detection means according to the present invention.

In FIG. 2, reflecting mirror 4-2. Lens 4-3 and C
The CCD unit 4 constituted by the CD 4-4 and the illumination lamp 4-1 are well-known document reading means. In the embodiment shown in FIG. 2, the light transmittance of the document is detected by the light receiving element 6 using the illumination lamp 4-1 in the document reading means.

Since the light transmittance detected by the light-receiving element 6 differs between when only one original is being fed and when two or more originals are being fed, the double feed detection of the original is different. It will be done.

[For production]

As explained above, according to the principle configuration of the present invention illustrated in FIG. 1, by automatically identifying the paper type of the document and controlling the selection of the reading mode corresponding to the paper type, It is possible to improve operability.

Further, according to the principle configuration of the present invention illustrated in FIG. 2, the illumination lamp 4-1 in the document reading device is used as a light source in the double feed detection device for the document, so that the double feed detection device can detect the double feed. It becomes possible to achieve simplification and contribute to cost reduction.

〔Example〕

FIG. 3 is a CCD output waveform diagram in the embodiment shown in FIG.
FIG. 4 is an operation flow diagram showing the operation in the embodiment shown in FIG. 1, FIG. 5 is an operation flow diagram showing the double feed detection operation in the embodiment shown in FIG. 2 shows another embodiment of the document reading device according to the present invention.

With reference to FIGS. 3 and 4, the operations of identifying the paper type of a document and controlling the selection of a reading mode corresponding to the paper type in the configuration shown in FIG. 1 of the present invention will be specifically described. Note that FIG. 3(A) shows the CCD output waveform when the paper type of the original is a thin paper original, and FIG. 3(B) shows the CCD output waveform when the paper type of the original is a transparent original.

In the embodiment shown in FIG. 1, the operation for identifying the paper type of the document is started by executing step (1) shown in FIG.

■ In step (1), when the illumination lamp 1-1 in the CCD unit I-1 is turned off, the transmission lamp 2-1 in the transmission unit 2 is turned on; The presence or absence of output is determined. In the case of a reflective original, most of the light irradiated by the transmission lamp 2-1 does not pass through the reflective original, so when there is no output from the CCD 1-4,
This means that the paper type of the original is a reflective original. In addition, if the paper type of the original is a thin paper original, the above CCDl
The output of CCD1-4 has a waveform as shown in FIG. 3(A), and when the paper type of the document is a transparent document, the output of CCD1-4 has a waveform as shown in FIG. 3(B). The waveform will look like this. Therefore, when there is an output from the CCDs 1-4, it means that the paper type of the original is a thin paper original or a transparent original.

Then, it is determined whether the paper type of the original is a thin paper original or a transparent original in step (4), which will be described later.

(2) If the determination in step (2) is that there is no output (that is, if the paper type of the document is a reflective document), the process moves to step (3). In step (3), the original reading operation is started with the transmission lamp 2-1 turned off and the illumination lamp 11 turned on so that the original reading operation on the reflective original can be executed efficiently. (Step (7)).

(2) If the determination in step (2) is that there is an output, the process moves to step (4), where it is determined whether the paper type of the document is a thin paper document or a transparent document. This determination is made based on the output waveforms (shown in FIG. 3) of the CCDs 1-4. That is, when the paper type of the original is a one-sheet original, the difference value d between the black level value a and the white level value in the output waveform of the CCD 1-4 (shown in FIG. 3(A)) is determined by the paper type of the original. CC when the type is transparent manuscript
The difference between the black level value a and the white level value b' in the output waveform of Dl-4 (shown in FIG. 3(B)) is small compared to the difference between the black level value a and the white level value b' in the output waveform of CCD 1-4. The difference value between the level value and the black level value is set to a predetermined threshold M
(e.g. M= (d+D)xi/2) compared to r
(If 1<MJ, it means a thin paper original; if rD>MJ, it means a transparent original.

(2) If the determination in step (4) is rd<M'' (!Tl, that is, if the paper type of the document is a thin document), the process moves to steps (5) and (6).

In step (5), the illumination lamps 1-1
and the transmission lamp 2-1, and in step (6), the white level value b (see FIG. 3(B)) is turned on.
) is set to a predetermined level value (for example, the white level value b'
), and then the original reading operation is started (step (7)).

■ Also, the determination in step (4) above is r[)>
In the case of MJ (i.e., when the paper type of the manuscript is a transparent manuscript)
In order to efficiently perform the document reading operation on a transparent document, the illumination lamp 1-1 and the transmission lamp 2-1 are left in the state 1! as set in step (1) above. (In other words, transmission lamp 2-1 → lighting, illumination lamp 1-
1→light off state), the document reading operation is started (step (7)).

As explained above, the embodiment illustrated in FIG. 1 improves operability by automating the identification of the paper type of the original, and also maintains stable contrast regardless of the paper type of the original. It is possible to obtain highly reliable image data with

Next, the operation of the document double feed detection means in the embodiment shown in FIG. 2 of the present invention will be specifically explained in relation to the operation flow shown in FIG. 5.

The embodiment shown in FIG. 2 uses an illumination lamp 4-1 for reading an original as a light source, detects the light transmittance of the original with a light receiving element 6, and detects the light transmittance (hereinafter referred to as detected transmittance α). ) and the light transmittance of one fed document to detect double feeding of the document.

Therefore, information regarding the light transmittance of the fed document (for example, the light transmittance (for one document) determined according to the paper type, thickness, etc., hereinafter referred to as the reference transmittance β) By executing the step (a) shown in FIG. 5 for setting , the detection operation regarding the double feed of the document is started.

(2) In step (a), the reference transmittance β of the document to be fed is set.

(2) In step (b), the illumination lamp 4-1 is turned on.

(2) In step (C), feeding of the original 5 is started.

(2) In step (d), the detected transmittance α is measured using the illumination lamp 4-1.

(2) In step (e), the detected transmittance α is compared with the reference transmittance β, and if “α × β”, the document feeding condition is normal. Therefore, the process moves to the next step (f) and the document is read.

(2) If the determination result in step (e) is "α>β", this means that double feeding of the document has occurred.

Therefore, the process moves to step (g), where the occurrence of an error is displayed.

As described above, the embodiment shown in FIG. 2 uses the illumination lamp in the document reading means as a light source in the double feed detection means, so that the double feed detection means can be simplified. In each of the other embodiments of the present invention, which will be described later with reference to FIGS. 6 to 8, basically the same as the embodiment shown in FIG. By using the illumination lamp in the double feed detection means, the double feed detection means is simplified.

In the illustrated embodiment in FIG.
The structure is such that a plurality of light receiving elements 6 are arranged in a direction perpendicular to the light receiving element 6, and the other structure except for this point is the same as the embodiment shown in FIG. 2 described above. Note that FIG. 6 is a plan view for explaining the arrangement of the light receiving element 6, and components other than the light receiving element 6 and the document feed roller 7 (
CCD unit shown in FIG. 2 4. illumination lamps 4-1, etc.) are omitted.

In FIG. 6, each of the plurality of light receiving elements 6 is associated in advance with a ground color area of a document such as a form. In the embodiment shown in FIG. 6, a double feed detection operation similar to the operation flow shown in FIG. 5 is performed after selecting the light receiving element 6 corresponding to the specifications (ground color area) of the form or the like. Therefore, the embodiment shown in FIG. 6 allows double feed detection at a desired position, and II! Double feed detection can be performed without being limited by the specification type of first-class originals.

Next, in both the embodiments shown in FIGS. 7 and 8, as in the embodiment shown in FIG. This is a double-sided document reading device designed to simplify the means. Note that numerals 8 and 9 in the figure are CCD units, 8-1 and 9-
1 is an illumination lamp, 8-3 and 9-3 are lenses, 8-4
and 9-4 represent COD, and other symbols correspond to FIG. Also, R is the surface reading position.

R2 indicates the back side reading position.

In the embodiment shown in FIG. 7, the light receiving element 6 is installed at a position facing the illumination lamp 8-1 with the document in between. That is, the document reading device is configured to perform double feed detection using the illumination lamp 8-1 in the CCD unit 8 as a light source in the double feed detection means.

In addition, in FIG. 7, the light receiving element 6 faces the illumination lamp 8-1 of the CCD unit 8! Although C
The light receiving element 6 may be installed opposite the illumination lamp 9-1 of the CD unit 9.

In the embodiment shown in FIG. 8, the illumination lamp of one of the CCD units (in FIG. 8, the illumination lamp 8-1 of the CCD unit 8) is used as the light source, and the illumination lamp of the other CCD unit is used as the light source.
CD (In Fig. 8, CCD unit 90CCD
9-4) to detect the light transmittance of the original and perform double feed detection.

The embodiments illustrated in FIGS. 7 and 8 described above perform operations basically similar to the operation flow illustrated in FIG. 5 described above.
Perform double feed detection. In the embodiment shown in FIG. 8, if the determination result in step (e) shown in FIG. Back side reading position R
After moving to 2, the document is read.

〔Effect of the invention〕

As explained above, according to the present invention, the paper type (
By automating the identification of reflective originals, thin paper originals, transparent originals), operability can be improved. Further, since it is possible to simplify the detection means for double feeding of a document, it is possible to greatly contribute to cost reduction.

[Brief explanation of drawings]

1 and 2 are respective diagrams of the principle configuration of the present invention, FIG. 3 is a CCD output waveform diagram in the embodiment illustrated in FIG. 1, and FIG. 4 is an operation flow diagram showing the operation in the embodiment illustrated in FIG. 1, FIG. 5 is an operation flow diagram showing the double feed detection operation in the embodiment shown in FIG. 2, and FIGS.
Figure 2 shows an explanatory diagram of a conventional example of double feed detection means. In the figure, 1.4.8 and 9 are CCD units 1-1.4
-1.8-1 and 9-11.1 @ bright lamp, 1-2 is a reflector, 1-3.4-3.8-3 and 9-3 are lenses, 1-4.4-4.8 -4 and 9-4 are CCDs, 2 is a transmission unit, 2-1 is a transmission lamp, 2-2 is a transmission plate,
Reference numeral 3 represents a document placement plate 5, a light receiving element 6, and a document feed roller 7.

Claims (3)

[Claims] (1) a first illumination lamp that illuminates one side of the document;
Equipped with a photoelectric conversion element for reading the image on the document surface,
In a document reading device configured to read the document by relatively moving the photoelectric conversion element and the document, a sensor is provided on the opposite side of the photoelectric conversion device across the document to read the other side of the document. A second illumination lamp that irradiates the document and an amount of light from the second illumination lamp that passes through the document are detected by the photoelectric conversion element, and the paper type of the document is determined based on the white level value of the detection signal of the photoelectric conversion device. What is claimed is: 1. A document reading device characterized by comprising: means for identifying. (2) A configuration that includes an illumination lamp that illuminates the surface of the document and a photoelectric conversion element that reads the image on the surface of the document, and that reads the document by moving the photoelectric conversion device and the document relatively. The original reading device includes a light receiving element that is provided on the opposite side of the photoelectric conversion element with the original in between and receives the light transmitted through the original by the illumination lamp, and reads two or more originals based on the output of the light receiving element. A document reading device configured to detect a double feed. (3) Two sets of reading units each having an illumination lamp and a photoelectric conversion element are arranged to sandwich the original and illuminate both sides of the original, and the two sets of reading units read information on both sides of the original. In the configured document reading device, the light transmitted through the document by the illumination lamp of one of the two sets of reading units is received by the photoelectric conversion element of the other reading unit, and two sheets are read based on the received light value. A document reading device characterized by comprising means for detecting the double feed of a document as described above.