JP3360306B2 - Scanner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder for a scanner using an image sensor or the like.

[0002]

2. Description of the Related Art Conventionally, in a scanner equipped with an automatic document feeder, the following methods have been studied as means for collecting a document from an original platen glass surface into the automatic document feeder. FIG. 5 is a first configuration diagram of a portion of a conventional apparatus for collecting a document in an automatic document feeder. The document 2a is fed while being pressed against the reading glass 11 for the automatic document feeder by the rotation of the roller 4. At this time, the document 2a is illuminated by the illumination device 6, and the illuminated document image is guided to the lens 8 by the mirror 7, and Original 2 which forms an image on sensor 9 and reads and passes through reading glass 11
a is collected in the automatic document feeder by the paper rake 5 inserted into the concave portion of the case beam 12.

FIG. 6 is a second structural view of a portion for collecting a document in the automatic document feeder. The document 2a is fed while being pressed against the platen glass 1 by the rotation of the roller 4, and the illumination device 6 is then turned on. The original 2a is illuminated by the illuminator, the illuminated original image is guided to the lens 8 by the mirror 7, formed on the image sensor 9, and read. The original 2a that has passed the reading position is inserted into the original rake groove 13 of the original platen glass 1. The paper rake 5 collects the paper in the automatic document feeder.

FIG. 7 is a third structural view of a portion for collecting a document in the automatic document feeder. The document 2a is pressed against the document guide transparent sheet 25 attached to the automatic document feeder by the rotation of the roller 4. The original 2a is illuminated by the illumination device 6 through the original guide transparent sheet 25 and the original platen glass 1, and the illuminated original image is guided to the lens 8 by the mirror 7, formed on the image sensor 9, and read. The document 2a that has passed the reading position is
The document is collected in the automatic document feeder by the document guide transparent sheet 25.

[0005]

In the document collecting means of the conventional automatic document feeder, in the first conventional example, a paper scoop is inserted between the platen glass and the glass for the automatic document feeder. A beam shape that closes the gap between the two glasses is required. When the case and the beam are integrated, molding failure such as insufficient filling or warping of the beam portion is likely to occur, and it is necessary to separate the beam shape. Further, the beam shape and the glass for the automatic document feeder are elongated in the main scanning direction, and the periphery of the automatic document feeder becomes weak.

Further, the second conventional example has a drawback in that a groove is formed in the original platen glass itself, so that the groove processing of the original glass becomes very expensive.

In a third conventional example, when a lens is focused on the surface of a normal document for reading the normal document,
When the automatic document feeder is used, the transparent sheet for the document guide is sandwiched between the platen glass and the document, so the lens focus shifts by the thickness of the sheet and conversely focuses on the document when the automatic document feeder is used. In such a case, there is a defect that the lens is usually defocused when reading the original.

[0008]

A scanner according to the present invention has a function of reading an original by keeping an original stationary and moving an optical system.
A scanner having a function of keeping an optical system stationary and moving an original by an automatic feeder to read the original, a transmission-type original table on which the original is placed in a stationary state, and an original so as to protrude from the upper surface of the original table. A transparent member provided at an end of the table to allow the automatically fed document to move in close contact therewith ;
The bright member sets the focal position of the optical system on the surface where the original moves closely.
Thickness that protrudes from the underside of the platen to enable correction
Having.

The scanner according to the present invention automatically feeds a document.
A paper scooping means used when reading by moving the apparatus is formed adjacent to a step formed by the transparent member and the document table .

Further, in the scanner according to the present invention, the original is kept stationary.
When reading by moving the optical system,
The reference position is a step formed by the transparent member and the platen.
are doing.

[0011]

[0012]

FIG. 1 is a block diagram of a method for collecting a document into an automatic document feeder in a scanner according to the present invention.

In the case of reading without using the automatic document feeder, the optical system is in a normal reading state 10b, and moves in the sub-scanning direction to read the document 2b.
The document image is illuminated by the illumination device 6 and guided to the lens 8 by the mirror 7 to form an image on the image sensor 9. When the automatic document feeder is used, the optical system is in the automatic document feeder use state 10a, and the document 2a is fed by the rotation of the roller 4 while being pressed against the auxiliary glass 3 which is a transparent plate. Original 2a that has passed
Is collected in the automatic document feeder by the step between the auxiliary glass 3 and the platen glass 1 and the paper rake 5. If the above-mentioned auxiliary glass 3 is not provided, the original 2a is sandwiched between the paper rake 5 and the original platen glass 1, and the original 2a cannot be separated from the original platen glass 1 and cannot be collected.

FIG. 2 is a first detailed view of a rake portion of a document of the automatic document feeder. The white reference is the lower surface of the auxiliary glass 3 and the white reference printing surface 23 which does not hinder reading and illumination. The original scale, which is printed and serves as a reference for the arrangement of the originals, is also printed on the upper surface of the auxiliary glass 3 and on the original scale printing surface 22 which does not hinder reading and illumination. The position of the document is determined by pressing the document edge against the edge. By coating a protective film 26 between the auxiliary glass 3 and the original table glass 1, breakage of the glass during transportation is prevented.

FIG. 3 is a second detailed view of a rake portion of a document of the automatic document feeder.
Reference numeral 4 denotes a position where the upper surface is a scale and the lower surface is a white reference, and when the original 2b is placed on the original platen glass 1, the scale can be checked through the auxiliary glass 3 and does not interfere with reading or illumination. When the original 2b is installed, the position of the original is determined by pressing the edge of the original against the edge of the auxiliary glass 3.

FIG. 4 shows the principle of the change of the lens focal point when using the automatic document feeder and during normal reading.

The lens optical path 14 during normal reading is refracted at the position of the refraction point 19 by the platen glass 1, forming an optical path 16 in the glass, and forms an image on the surface of the platen glass 1. In this state, if the optical path 14 is refracted like the optical path 16 at the position of the overhead line 21, the optical path becomes an overhead optical path 17. In order to obtain an optical path similar to the optical path 17, the optical path 15 is refracted at the refraction point 20 by the auxiliary glass 3, an optical path 18 in the glass is obtained, and the auxiliary glass 3 protrudes to the upper surface in order to press the document at the focal point of the optical path 18. Let it.

According to the above principle, an optimum lens focal position can be obtained both when the automatic document feeder is used and when it is not used.

[0019]

According to the present invention, an original is fed into the automatic original feeder without forming grooves on the original glass, and without providing a separate glass apart from the original table glass in the sub-scanning direction. It is very inexpensive and easy to process.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of a scanner according to the present invention.

FIG. 2 is a detailed view of a scanner according to the present invention.

FIG. 3 is a detailed view of a scanner according to the present invention.

FIG. 4 is an optical principle diagram of a scanner according to the present invention.

FIG. 5 is a diagram illustrating the configuration of a conventional scanner.

FIG. 6 is a diagram illustrating the configuration of a conventional scanner.

FIG. 7 is a diagram illustrating the configuration of a conventional scanner.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 platen glass 2a document for automatic document feeder 2b normal reading document 3 auxiliary glass 4 automatic document feeder roller 5 automatic document feeder paper rake 6 lighting device 7 mirror 8 lens 9 image sensor 10a automatic document feeder use state 10b normal Reading state 11 Reading glass for automatic document feeder 12 Case beam 13 Document rake groove 14 Lens light path for normal reading 15 Lens light path for automatic document feeding 16 Optical path in glass 17 Overhead light path 18 Optical path in glass 19 Refraction point 20 Refraction point 21 Overhead line 22 Original scale printing surface 23 White reference printing surface 24 Parts for both scale and white reference 25 Transparent sheet for document guide 26 Protective film

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/04 G03G 15/00 H04N 1/00 H04N 1/12

Claims (4)

(57) [Claims] 1. A scanner having a function of reading an original by moving an optical system while the original is stationary and a function of reading the original by moving the optical system by an automatic feeder while the optical system is stationary. A transmissive platen to be placed in a stationary state, and a transparent member provided at an end of the platen so as to protrude from an upper surface of the platen and for the automatically fed document to move closely , The transparent member is provided with the optical
In order to be able to correct the focal position of the system,
A scanner with a thickness that protrudes from the surface . 2. The method according to claim 1, wherein the original is moved by an automatic feeder.
The paper scooping means used when reading
2. The scanner according to claim 1, wherein the scanner is formed adjacent to a step formed by a material and the platen. 3. The apparatus according to claim 1, wherein the original is stationary and the optical system is moved.
When scanning a document, the reference
3. The scanner according to claim 2, wherein the scanner is a difference portion . 4. The transparent member allows the original to move closely.
Having a thickness that allows the focal position of the optical system to be corrected
The scanner according to any one of claims 1 to 3 .