JPH0439948B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] In a document reading device that places a document on a transparent top plate and reads the document using reflection from the bottom surface of the transparent top plate, a document reader is used to detect the starting edge of the document. It is disclosed that a frame plate is provided against which the starting edge of the document abuts, and a light reflector is disposed on the lower surface of the frame plate, so that the starting edge of the document can be detected correctly.

[Industrial application field]

The present invention relates to a document reading device, and particularly to a document reading device that reads a document using reflection by placing the document on a transparent top plate, and is capable of correctly detecting the starting edge of the document.

[Problems to be solved by conventional technology and invention]

For example, in an OCR image scanner called a flatbed type, a document is placed on a transparent glass top plate, and the document cover is held down from above.
A light source that moves relative to the lower surface of the top plate detects reflected light from the original that returns via the top plate.

In this case, for example, when reading a document in which a predetermined text field exists at a predetermined position on the document, the starting edge of the document is correctly detected and the distance from the starting edge is measured. It is necessary to determine the above-mentioned predetermined character entry field. For this purpose, a document abutting frame plate is placed on the top plate, and the original placed on the top plate is read by correctly abutting its starting edge against the document abutting frame plate. will be started.

In this case, the following problem arises. That is, when reading with the relatively moving light source, the reading position is initially the lower surface of the document abutting frame plate,
Next, move to the beginning of the manuscript. In this case, it is desirable that the intensity of the reflected light can clearly distinguish between the intensity of the reflected light from the lower surface of the document abutting frame plate and the intensity of the reflected light from the starting edge of the document. For this reason, it is thought that if the lower surface of the document abutting frame plate is made black, the contrast with the white document will be clear. However, it has been found that doing so is not always desirable.

FIG. 3 is an explanatory diagram illustrating this point.

Figure 3 A is a manuscript placed on a transparent top plate (white)
Figure 3B shows the state when there is a black sheet on the bottom surface of the document abutting frame plate, and FIG. 3C shows the state where a light reflector exists on the bottom surface of the document abutment frame plate. It represents the state when

In the figure, 1 is the original, 2 is the transparent top plate, 3 is the fluorescent lamp, 4 is the original abutment frame plate, 5 is the reading reflected light, 6
is the light that creates the reflected light inside the top plate, 7 is the light reflected inside the top plate,
8 represents light directed toward the reading point.

Consider a situation where a document (white) is being read as shown in FIG. 3A. In this case, the read reflected light 5 reflected from the reading point B is superimposed with the reflected light from the light 8 and the reflected light 7 inside the top plate caused by the light 6 reflecting inside the top plate. There is. Then, with the reading reflected light 5 having the superimposed light intensity, point B is read as white, as shown on the right side of the figure.

Considering this point, when a black sheet is placed on the lower surface of the original abutment frame plate 4 as shown in FIG. 3B, the following results will be obtained. That is, when the black sheet portion is being read, the read reflected light 5 is sufficiently small and is read as black. However, when the time has come to read the starting edge of the original 1 that is abutted against the original abutting frame plate 4 (that is, when reading point A),
There is reflection from point A based on light 8, but there is virtually no reflected light 7 within the top plate based on light 6.
The light intensity of the reading reflected light 5 is relatively small (the third
(compared to the case in Figure A). As the light source moves and the point to the right of point A is read, the amount of reading reflected light 5 increases as shown on the right side of the figure, and is finally determined to be white. Therefore, it becomes difficult to detect that the starting edge of the document 1 is at the point A. The white sheet portion is provided on the document abutment frame plate 4 in order to allow the apparatus to correctly remember the white level when the light source is in the so-called home position.

Compared to the case of FIG. 3B, if a reflector is placed in place of the black sheet portion as shown in FIG. 3C, at the position of point A, as shown on the right side of the figure,
The amount of reading reflected light 5 increases rapidly, making it possible to correctly detect the starting edge of document 1. This is because the reading reflected light 5 from the point immediately to the left of point A is specularly reflected on the reflector and almost no longer exists, and when reading from point A is performed, it suddenly increases. It is from. and,
When reading is being performed from point A, the amount of light reflected within the top plate 7 can be used as the reading reflected light 5.

[Means for solving problems]

The present invention solves the above problems by disposing a reflector on the lower surface of the document abutting frame plate.

Figure 1 shows the principle configuration diagram of the present invention, and Figure 1A
1B shows a conceptual side sectional view of the main part, and FIG. 1B shows a bottom sectional view of the main part. In the figure, 1 is the original, 2 is the transparent top plate, 3
1 is a fluorescent lamp, 4 is a document abutting frame plate, 5 is a reading reflected light, 9 is a document cover, 10 is a reflection mirror, and 11 is a carriage, which allows the fluorescent lamp 3 and reflection mirror 10 to be moved in the direction of arrow A in the figure. 12 represents a fixed reflection mirror. Further, on the lower surface of the document abutting frame plate 4, as shown in FIG. 1B, a light reflector 13 shown as a reflective sheet is arranged.
A white sheet 14 is placed at a position corresponding to the home position of the light source. Also, the top plate 2
A black sheet 14' is placed on the bottom surface of the document 1 at a location where the document 1 is not supposed to exist. Further, a light reflector 15 is arranged on the lower surface of the document cover 9.

[Effect]

As shown in FIG. 1A, while the carriage 11 with the fluorescent lamp 3 is in the home position, the reflection from the shown white sheet 14 is read to confirm the white level. Then, the carriage 11 sequentially moves in the direction shown in FIG. 1A, detects the starting edge of the document at point A, and thereafter operates to read the reflection from the document 1.

During this time, as described above with reference to FIG. 3C, the amount of reading reflected light 5 increases rapidly at the starting edge of the original 1, making it possible to correctly detect the starting edge of the original 1. In addition, by arranging a light reflector on the lower surface of the document cover 9, it is possible to
This makes it easy to detect edges.

〔Example〕

FIG. 2 shows an embodiment corresponding to the cross-sectional view taken along line X-X' shown in FIG. 1B. In the figure, reference numeral 4 is a frame plate against which the original is abutted, 2 is a transparent top plate, 13 is a reflective sheet, 14 is a white sheet, 16 is a frame corresponding to the position where the original is abutted, 17, 18,
19 each represents an adhesive. In addition, adhesive 1
Regarding No. 9, a particularly transparent adhesive is required.

The cross section taken along the line XX' in FIG. 1B can also be considered to have substantially the same structure as shown in FIG. 3 with respect to the original abutting frame plate 4. The light reflected from the white sheet 14 provides the white level at the home position. The starting edge of the original 1 is detected when the reflected light from the reflection sheet 13 becomes the reflected light at the starting edge of the original 1 as shown in FIG. 3C.

Note that the white sheet 14 and reflective sheet 13 shown in FIG. 2 may be formed on the frame 16 directly by surface treatment of the frame 16.

Further, as shown in FIG. 2, in the present invention, the white sheet 14 is placed from the surface of the transparent top plate 2 with a microscopic space interposed therebetween. If such microscopic spaces are not created, the surface of the white sheet 14 may become dark due to light interference.
In the present invention, the white sheet 14 is supposed to appear sufficiently white.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to correctly detect the starting edge of a document, and one problem in reliably reading the written contents of the document is solved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention, FIG. 2 is a diagram showing the construction of an embodiment, and FIG. 3 is an explanatory diagram illustrating problems. In the figure, 1 is the original, 2 is the transparent top plate, 3 is the fluorescent light, 4
1 is a document abutment frame plate, 5 is a reading reflected light, 9 is a document cover, 13 is a light reflector (reflection sheet), 14 is a white sheet (white surface), 15 is a light reflector (reflection sheet)
represents.

Claims (1)

[Scope of Claims] 1. A document cover 9 that presses the document 1 placed on the transparent top plate 2 from above is provided, and a document abutment frame plate 4 is placed on one end side of the transparent top plate 2. At the same time, the document 1 placed on the transparent top plate 2 with one end abutted against the document abutting frame plate 4 is moved relative to the back side of the transparent top plate 2 along the transparent top plate 2. In a document reading device configured to emit light from a light source 3 through the transparent top plate 2 and read reflected light 5 from the document 1, the document abutting frame plate 4 has the following features: Transparent top plate 2
A light reflector 13 is disposed at least near the end of the side surface against which the original 1 is abutted, and a light reflector 13 is disposed at least near the end of the original abutting frame plate 4 on the transparent top plate 2 side. A document reading device characterized in that a white sheet 14 is formed from the surface on the document abutting frame plate 4 side through a microscopic gap. 2. The document cover 9, which presses the document 1 placed on the transparent top plate 2 from above, has a light reflector 15 disposed on the surface in contact with the document 1. The document reading device according to scope 1.