JPH05122466A - Original identification device - Google Patents

Abstract

PURPOSE:To provide an original identification device capable of realizing a function to surely identify original size with a low cost without being affected by original density. CONSTITUTION:The original crimping plane of a platen cover 1 is colored in two colors of yellow and white, and an optical unit scans an original surface at respective area, and density data obtained at that time is compared with the density of the original crimping plane of the platen cover 1 stored in an MPU in advance, and a color lighter than that is detected at a yellow original crimping plane, and the color deeper that at a white original crimping plane, and the position of a boundary detected at respective area is compared with the original size stored in advance, and larger size is set as the original size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an original document identifying apparatus for identifying an original document by reading the original document and the original pressure contact surface.

[0002]

2. Description of the Related Art Conventionally, a method of identifying a document has been proposed for a copying machine or the like.

For example, a method of identifying a document size by providing a platen cover with a plurality of photosensor units each including a light emitting element as a light source for document identification and a light receiving element for receiving light reflected by the document (Japanese Patent Laid-Open No. 59-59). -180
535).

Further, a pressure plate for holding an original document having a spectral reflectance in the short wavelength region lower than the spectral reflectance in the wavelength region in which the spectral sensitivity peak of the electrophotographic apparatus is present, and the wavelength region in which the spectral sensitivity peak is in the spectral region of the pressure plate. There are a light detecting means existing in a region having a lower reflectance and a method for detecting the document size by the output of the light detecting means (see Japanese Patent Laid-Open No. 61-232440).

[0005]

However, the above conventional configuration has the following problems.

First, in the method proposed in Japanese Patent Application Laid-Open No. 59-180535, when the original density is thin and semi-transparent and the reading density is large when copying the original, the photosensor unit is read as a shade of black. There is a problem. Further, when the original size is manually selected, an original smaller than the specified original size is used, so that the original is not located at a position where the photosensor unit is hidden and the shade of the photosensor unit may be read as black. .. Further, there is a drawback that the cost becomes high because a large number of photo sensor units are used.

Next, according to the method proposed in Japanese Patent Laid-Open No. 61-232440, when the original used when detecting the original size has the same spectral reflectance as the original pressing plate, the original and the original pressing plate are used. There is a problem that it cannot be distinguished. Further, as in the former method, a large number of light detecting means for detecting the size of the original are used, so that the cost becomes high, the number of parts increases, and the number of manufacturing steps also increases.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an original document identifying apparatus which can realize a function of reliably identifying an original document at low cost.

[0009]

In order to achieve this object, a document identifying apparatus according to the present invention comprises a first area and a dropout color formed by a first color, which is a dropout color, on a document crimping surface. A document pressing unit including a second region formed of a second color that is lighter than the first color; a reading unit that reads the document pressed by the document pressing unit and the document pressure-bonding surface; The density signal from the reading means is compared with density signals corresponding to the first and second colors stored in the memory in advance, and a color lighter than the first color is detected in the first area, In the second area, a detecting means for detecting a boundary line between the original and the original pressure-bonded surface by detecting a color darker than the second color, and a detecting means for detecting the boundary line in the first and second areas, respectively. Position and from the control means described below The comparing the signal indicative of the draft size 1
Control unit that controls the detection unit and the identification unit to identify the original size in each of the area 2 and the second region, and determines the larger one of the two types of original sizes identified by the identification unit as the original size. Document identifying device having means

[0010]

With this configuration, the densities of the two color areas of the original pressure bonding surface composed of two color dropout colors are compared, and the boundary line between the original and the original pressure bonding surface is detected to reliably detect the original. Allows you to identify the size.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the outline of an image reading apparatus according to the present invention. In FIG. 1, 1 is a platen cover for pressing an original, 2 is an original table on which the original is placed, 3 is a white reference plate used for shading correction, 4 is a light source for reading the original, and 5 is reflection from the original. A mirror for guiding the optical path of the optical power in a predetermined direction, a lens 6 for collecting the reflected light guided by the mirror 5, a light receiving element 7 for converting the image information collected by the lens 6 into an electric signal, and 8 for the above 4 to 7 is an optical unit, 9 is a linear pulse motor for moving the optical unit along a platen, 10 is a mover for holding the optical unit 8, and 11 is a stator fixed to the apparatus body.

Further, FIG. 2A shows a color arrangement relationship between the detection area at the time of detecting the original size and the original pressure-bonded surface of the platen cover 1. In this embodiment, yellow and white 2
As shown in the figure, a first position (hereinafter referred to as 1stP) and a second position (hereinafter referred to as 2ndP) are provided. The density comparison is performed at these two points, details of which will be described later.

Further, FIG. 2B shows an original placing surface on which an original is placed, and shows a state in which an original of B5 size is placed. As shown in the figure, reference numeral 20 is a document set reference position which serves as a reference when a document is placed. FIG. 3 shows a block diagram of the identification circuit of the present invention. Reference numeral 12 is a shading correction circuit for distortion correction, 13 is a comparator for comparing the image density read by the optical unit 8 with the density data of the platen cover previously stored in the central processing unit described later, and 14
Is a logical product circuit for comparing the result from this comparator with the data of the original size stored in the central processing unit, which will be described later, to calculate an appropriate original size, and 15 is the data to the comparator 13 or the logical product circuit 14. , A central processing unit (hereinafter referred to as MPU) for storing data such as general control and various document sizes, 16 is an output port for relaying data sent from the MPU 15, and 17 is a result output from the AND circuit 14 to the MPU 15. Input port to relay to, 18 is MPU15
Is a timer for timing and sending the document data from the AND circuit 14 to the AND circuit 14, and 19 is a signal line for sending the document density read by the optical unit 8 to the document identifying circuit and the image processing circuit.

FIG. 4 shows a flow chart of the process of the present invention. The execution procedure of the present invention will be described below with reference to FIGS.

When the start button is pressed (step 1),
The light source 4 is turned on (step 2), and shading correction is performed using the white reference plate 3 in FIG. 1 (step 3). Next, as a preliminary scan, the optical unit 8 moves to 1stP in FIG. 2A (step 4). Next, density measurement for identifying the original is performed. Here, as for the placement position of the document, as shown in FIG. 2B, the lower left of the document is aligned with the document setting reference position 20. Then, the density of the original is measured by performing a preliminary search on the optical unit before performing the normal reading operation. When measuring the density of the document, the document density is detected by reading in the main scanning direction from above the document mounting surface. Next, the density data of the original obtained by the optical unit 8 and the density of the original pressure-bonded surface of the platen cover 1 stored in the MPU 15 in advance are compared by the comparator 13. The presence / absence of a document whose density is lighter than the density stored in this MPU is identified (step 5). At this time, an enable signal corresponding to the detection range of each original size is sent from the MPU 15 through the timer 18.
A3, B4, B5, A4, and A5 and the document size data are sequentially output to the AND circuit 14 (step 6).
At the same time, the output result of the comparator 13 is output to the logical product circuit 14, and the logical product circuit 14 discriminates the proper size and presence / absence of the original. At this time, how to identify is within A5 size (), A5 size and B in the main scanning direction of the document in FIG. 2B.
Assuming five original patterns between 5 sizes (), between B5 size and A4 size (), between A4 size and B4 size (), and between B4 size and A3 size (). If it is determined that there is a break, that is, a boundary between the document and the platen cover, the size of the document is A5 size. Similarly, the document size is recognized as B5 version, A4 version, B4 version, A3 version, and so on. Here, the recognized document size is set as a first size (hereinafter referred to as 1st size) (step 7). At 1stP, the original pressure surface is colored with a yellow dropout color. Therefore, the original size is recognized by identifying the presence or absence of an original having a lighter density than this, and the first size (hereinafter referred to as 1st size). ). However, if only the 1stP is used for identification, if the original has a high density, it is determined that there is no original even if the original is actually present. Therefore, the optical unit 8 is moved to the 2nd P (step 8), and the platen cover 1 is pressed in the area (2nd P) colored with the white dropout color on the original pressure-bonding surface.
The same procedure as above is performed (steps 9 and 10).
In the 2ndP, since the original pressure surface is colored with a white dropout color, the original size is recognized by identifying the presence or absence of an original with a darker density, and
Size (hereinafter referred to as 2nd size) (step 1
1). Next, it is confirmed whether or not the first recognized document size, the 1st size, is valid (step 12). If it is determined to be invalid, it is confirmed whether the second size is valid (step 13), and if it is also determined to be invalid, it is determined that there is no document. In step 12, 1
When the st size is valid, it is confirmed whether the second size is valid (step 15). If it is determined to be valid, the sizes of the 1st size and the 2nd size are compared (step 16), and the larger one is determined as the document size (step 1).
8, step 17). If it is determined that the document is invalid in step 15, the 1st size is recognized as the document size (step 18). Further, when it is validated in step 13, the 2nd size is determined as the document size.

When the document size is determined as described above, the optical unit 8 of FIG. 1 moves to the home position (step 19). Thereafter, the reading operation is started with the recognized document size (step 20). In the present invention,
Although the size of the original is determined by detecting the width of the original, it goes without saying that the area for detecting the presence or absence of the original can be changed and added by detecting the vertical width of the original.

[0017]

According to the present invention, the original document pressing means having the original pressing surface formed of a plurality of dropout collars, the reading means for reading the original and the original pressing surface, and the original and original pressing based on the signal obtained by the reading means. The original and the original are compared by detecting the boundary between the original and the original size, and comparing the densities of the two color areas of the original press-bonded surface composed of two dropout colors. By detecting the boundary line with the pressure-bonding surface, it is possible to reliably identify the size of the document.

Further, since no dedicated light receiving element or light emitting element is used for document identification, it is possible to realize an excellent document identification apparatus which can be provided with a low cost and a simple structure.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of an image reading apparatus to which a document identifying apparatus according to an embodiment of the present invention is applied.

FIG. 2A is an explanatory view showing a color arrangement relationship of a document pressure-bonding surface in one embodiment of the present invention. FIG. 2B is an explanatory view showing a document placement surface in one embodiment of the present invention.

FIG. 3 is a block diagram of a circuit for document identification according to an embodiment of the present invention.

FIG. 4 is a flowchart showing a flow of a document identifying operation according to an embodiment of the present invention.

[Explanation of symbols]

 1 Platen Cover 2 Platen 3 White Reference Plate 4 Light Source 5 Mirror 6 Lens 7 Photosensitive Element 8 Optical Unit 9 Linear Pulse Motor 10 Moving Element 11 Stator 12 Shading Correction Circuit 13 Comparator 14 AND Circuit 15 MPU (Central Processing Unit) 16 Output Port 17 Input Port 18 Timer 19 Line 20 Original Setting Reference Position

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masato Kotobuki 2-3-3 Shimomeguro, Meguro-ku, Tokyo Matsushita Dentsu Co., Ltd.

Claims (2)

[Claims] 1. A first area having a first color which is a dropout color and a second area which is a second color lighter than the first color, which is a dropout color, on the original pressing surface. An original pressing unit composed of a region, a reading unit for reading the original pressed by the original pressing unit and the original pressing surface, and a first memory for storing in advance the densities of the first color and the second color. Means for comparing the density signals corresponding to the first and second colors output by the first storage means with the density signals of the original and the original pressure-bonded surface output by the reading means, and the first area Then, detecting means for detecting a boundary between the original and the original pressing surface by detecting a color lighter than the first color and a darker color than the second color in the second area, and various original sizes And a second storage means for storing The signal indicating the document size output by the means is compared with the signal indicating the position of the boundary detected in each of the first and second areas by the detection means, and the document size is determined in each of the first area and the second area. A document identifying apparatus comprising: an identifying unit for identifying; and a control unit for determining the larger one of the two types of document sizes identified by the identifying unit as the document size. 2. The document identifying apparatus according to claim 1, wherein a boundary of the dropout color is set near a reading start position.