JPH0331838A - Image reading device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an image reading device, and in particular, the present invention relates to an image reading device, and particularly to an image reading device, in particular, an image reading device that uses a thick book with a closed spine, such as R#J4, which has concave and convex portions. The present invention relates to an image reading device suitable for, for example, a copying machine cap, which is capable of always accurately reading image information on a document surface, even for a document surface having parts, regardless of changes in unevenness of the document surface. .

(Prior Art) Among the image reading devices conventionally used in copying machines and the like, there is one in particular that reads image information by placing the document surface on the document table F in the F direction and reading the image information. 60-106266
This method has been proposed in Japanese Patent Application Laid-Open No. 6169059, etc.

With conventional image reading means, for image information such as thick book-type originals where the surface of the original to be read is not entirely flat but has uneven parts, for example, the uneven state is detected by the detection means and the image information is detected. The document surface is read by the image reading means using No. 4 from the detection means.

FIG. 14 is a schematic diagram of the main parts of the optical system of the image reading device proposed in Japanese Patent Application Laid-Open No. 130106266 when reading image information on the document surface F with the document surface placed in the F direction. .

In the figure, reference numeral C146 denotes a document surface detection section, which uses two projecting lenses 142 to form a spot image on the second surface of an upwardly facing document placed on the first surface of the document table with the light beam from the light emitting diode 143. A spot image from the original 2 is formed on the surface of the image sensor 145 by the light receiving lens 146. At this time, the uneven state on the surface of the document 2 is determined by detecting a change in the position of the spot image on the surface of the image sensor 145 due to a change in the height of the document 2.

Based on the output signal from the detection means 146, image information on the two sides of the original is read by the image reading means +47.

That is, in the figure, the original surface of the original 2 is illuminated by a light beam from a light source (not shown), and the reflected light beam from the original surface is guided to the imaging lens 3, and the light beam on the second surface of the original is illuminated on the line sensor 4. It forms an image. Then, the housing 141 is moved along the document surface of the document 2 as indicated by an arrow 148 shown in the same figure.
The image information on the two sides of the original is read by

(Problems to be Solved by the Invention) In the image reading device shown in FIG. The uneven state of the document surface is detected by scanning the surface detection unit 146 along the two sides of the document and detecting the position where a spot image reflected from the document surface is formed on the image sensor surface. Does the entire device become larger, requiring more space on top? There was a tendency to become 5lfi.

Even when part of the image information for reading has a curved surface (unevenness), such as in a book-type original, the present invention has a simple configuration that allows the document surface detection unit to easily and accurately detect the uneven shape. An object of the present invention is to provide an image reading device that can accurately read an image of the entire document surface using an image reading section using a signal from the document surface detection section.

(Means for Solving the Problems) The image reading device of the present invention presses a J12W original on a document table surface with a transparent member partially provided with a marked line, and illuminates the marked line of the transparent member with an illumination means. The luminous flux of l
The distance between the transparent member and the document surface is determined by illuminating at an incident angle of 0 degrees or more, and detecting the positional relationship of the projected image of the marked line on the document surface with a detection means. The image reading means scans and reads the image information on the surface of the document using signals from the document.

(Embodiment) FIG. 1 is a schematic diagram of a main part of an embodiment of an image reading device of the present invention.

In the figure, reference numeral 1 denotes a document table, and 2 denotes a book type original, which is placed on the document table 1 with its surface facing upward.

A transparent member 7 presses the R product 2.

A second part of the transparent member 7 outside the image reading area of the original 2 is
A plurality of equally spaced marked lines 8 are provided as shown in the figure.

Reference numeral 9 is a light source for illuminating the marking line, for example, a point light source, which illuminates the marking line on the surface of the transparent member 7! I8 is illuminated at an incident angle of 10 degrees or more. Reference numeral 5 denotes a light source for illuminating the original, which uniformly illuminates two sides of the original.

Reference numeral 3 denotes a document reading lens, and the image information on the two sides of the document illuminated by the light beam from the light source 5 is transferred to mirrors 6a, 6b, and 6c.
The image is formed on the 4th surface of the image reading means.

The image reading means 4 is composed of, for example, a CCD or the like in which a plurality of light receiving elements are arranged one-dimensionally, and converts image information on the two sides of the document into electrical signals.

In this example, each V element 3.4. , 6a.

The image reading section 101 having 6b, 6c, and 7.9 is housed in one housing, and includes a first unit consisting of 6a and 9, a second unit consisting of 6b and 6C, and a third unit consisting of 3.4. The first unit and the second unit are movable in the direction of arrow 102 at a speed ratio of 2:1, and scan and read image information on two sides of the document.

In this embodiment, image information on the uneven original 2 is read as follows.

First, the light source 9 illuminates ll18 on the transparent member 7 surface at an incident angle of 10 degrees or more, so that the projected image 8a of the gauge line 8 is formed on the document 2 surface with a predetermined deviation ff1e.

Figure 3 shows the transparent member 7 and document surface 2 of fili 8 at this time.
FIG. 8 is a schematic diagram showing the relationship with a projected image 8a on a.

When the angle of incidence is less than 10 degrees, the deviation Ig of the projected image 8a becomes too small, which is not good.When observing the projected image 8a at this time from directly above the transparent member 7, the projection image 8a and the projection line 8 as shown in the figure The horizontal distance to the image 8a is 4. The height from the marked line surface 7a of the transparent member 7 on which the marked line 8 is provided to the document surface 2a.

If the angle of incidence of the illumination light from the light source 9 on the transparent member 7 is θ, then 12=h − tan θ, so #ffi reading T! shown in FIG. 1 is obtained. Part i】01
When scanned at a speed F in the direction of arrow +02, the image reading means 4
For example, the output signal from is as shown in Figure 4 (
It is calyxed. This time mark! 18 and the projected image 8
The time difference t with the signal regarding a is L=J2/F=h'L
It becomes a0θ, that is, it becomes.

From this, the height h from the marked line surface 7a of the transparent member 7 to the document surface 2a is determined over the entire surface of the document 2.

In this embodiment, before image reading, the image reading N101 performs pre-scanning to obtain the height h at each point on the two sides of the document, and stores the height h at this time in a storage unit (not shown), for example. Next, the image information on the second side of the original is transferred to the image reading unit lot.
When scanning and reading, for example, the reading lens 3 and the image reading means 4 are moved integrally on the optical axis by a pulse motor shade using signals stored in the storage unit, or the document table 1 is driven vertically by a pulse motor or the like to control the focusing 71I so that the image information on the second side of the document is focused on the fourth side of the image reading means. ing.

FIG. 5 shows a block diagram of a series of signal processing for image reading in this embodiment.

FIG. 6 is a schematic diagram of a part of a second embodiment of the present invention.

In this figure, the area near the transparent N material 7 that presses the original 2 and the original [2] is shown. It is composed of a grid of

An image reading section 10 similar to that shown in FIG. 1 including a light source 9
1 (not shown) to scan the two sides of the original, and sequentially illuminate the marked lines 8 on the transparent member 7 with the light beam from the light source 9. Then, the relationship between the marked line 8 and the projected image 8a formed on the second surface of the original document is detected by an image detecting means 4 (not shown). For reference, the figure shows the anq relationship between the light source 9 and the transparent member 7 for M and N at three locations on the second side of the document.

Figure 8 (L), (M), and (N) are respectively the digits WtL of Figure 6.
, M, and N are explanatory diagrams of output signals obtained by the image reading means 4.

In (A) of FIGS. 8(L), (Ml, and (N)), the solid line is a signal based on the marked line 8 on the surface of the transparent member 7, and the broken line is the projected image 8a of the marked line 8 projected onto the second side of the document. Based on < tS.

The signal actually obtained by the image reading means 4 is shown in Fig. 8 (1,).
, (M>, +N), as shown in (B), <fM is obtained based on the superimposed image of the signal based on the marked line 8 and the projected image 8a. When the output signal at this time is passed through a low-pass filter, the results are shown in Figures 8 (L) and (M).

As shown in (C) of (N), the flow a is determined.

The values shown in FIGS. 5 and 8 (+-), (M), and (C) of (N>) are pressed by the 9 image reading unit 101, which changes depending on the distance between the eJ line surface 7a of the transparent substrate 7 and the document surface 2a. When the document surface is scanned, the signal related to the DC component becomes as shown in FIG. 9, for example.

Now, the incident angle of the luminous flux is θ, and the DC component is ■. , where P is the pitch of the marked lines 8a, and h is the height from the document surface 2a to the marked line surface 7a, 2P.

The document surface 2a is pre-scanned by the image reading unit +01, the marked line and its projected image are read by the image reading unit 4, and the output is passed through a low-pass filter to obtain a DC component, which is AD converted and stored in a storage unit (not shown). When reading the image information on the document surface 2a, the image on the document surface 2a is read using the same method as shown in the first embodiment of FIG. 1 using the signals stored in the storage section. Information is imaged on the image reading means 4 in a focused state. This allows highly accurate image reading.

FIG. 10 shows a block diagram of a series of signal processing for image reading in this embodiment.

FIG. 1+(A) is a schematic diagram of a part of the main part of a third embodiment of the present invention.

In the figure, only the original 2 placed a on the original platen II and the vicinity of the transparent portion 7 are schematically shown.

FIG. 11(B) is a schematic diagram when FIG. 11(A) is viewed from the X direction.

In this embodiment, the PJ line 8 is constituted by a straight line mark parallel to the scanning direction during image reading on the surface of the transparent member 7, as shown in FIG.

As shown in FIGS. 1+ (Δ) and (B), the marked line 8 illuminated by the light beam from the light source 9 at an incident angle θ forms a projected image 8a on the document surface 2a. The projection fli 8 a is a distance I2 in the main scanning direction according to the height h from the marking surface 7a to the document surface 2a.
It shifts by a. The deviation rjl 42a at this time is Qa=h-Lanθ.An image reading unit +01 (not shown) having a light source 9 and similar to that shown in FIG. is determined at each point on the document surface 2a, and from this, the height h at each point on the document surface 2a is determined from h:βa/tanθ, and the height h at this time is stored in the storage section as in the first embodiment. Remember it.

Image information on the entire surface of the document 2 is formed in focus on the surface of the image reading means 4 by a method similar to that described in the first embodiment of FIG.

FIG. 13 shows a series of block diagrams for image reading in this embodiment.

In each of the above embodiments, the WaS may have any shape as long as the distance (height) between the transparent member and the document surface can be detected.

(Effects of the Invention) According to the present invention, the position W1 relationship of the projected image of the marked line provided on a part of the transparent member that presses the document onto the document surface is determined using an image reading means, and the detection result at this time is obtained. By using it, you can easily handle even the uneven surface of book type manuscripts! With a simple configuration, it is possible to achieve an image reading device that can accurately read image information on the entire surface of a document.

[Brief explanation of drawings]

1, 6, and 1 [FIG. 1 shows the first, second, and second embodiments of the present invention, respectively.
The main part schematic diagram of the third embodiment, FIG. 2, FIG. 7, and FIG. 12 are respectively shown in the first embodiment of the present invention. FIGS. 3 and 4 are explanatory diagrams of the marked lines on the surface of the transparent member according to the third embodiment. FIGS.
0° FIG. 13 is a series of block diagrams during image reading according to the first, third and third embodiments of the present invention, and FIGS. 8 and 9 are diagrams obtained from the image detection means in the second embodiment. FIG. 14 is a schematic diagram of a conventional image reading device. In the figure, 1 is a document table, 2 is a document, 3 is a document reading lens, 4 is an image reading means, 9 is a light source, and 6a. 6b and 6c are mirrors, 7 is a transparent member, and 8 is am. lot is an image reading unit, 2a is a document surface, and 7a is a marked line surface. Run it Sir f Toki 9 ke 1 Rod 13 Diagram

Claims (1)

[Claims] (1) A document placed on a document table is pressed with a transparent member having a marked line on a part thereof, and the marked line of the transparent member is illuminated by the light beam from the illumination means at an angle of 10 degrees or more with respect to the transparent member. The distance between the transparent member and the document surface is determined by illuminating at a corner and detecting the positional relationship of the projected image of the reference line on the document surface with a detection means, and using the signal from the detection means. An image reading device characterized in that image information on the surface of the document is scanned and read by an image reading means.