JP2007010952A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading apparatus in which a user can easily attach and remove a detachable original mat at an accurate position.
A transparent document table, a document table first illuminating unit provided below the document table, a document reading unit provided below the document table, and a document table first provided above the document table. A second illumination unit, a document mat for covering the document table, a plug provided at the first end of the document mat, a first protrusion projecting in the thickness direction of the document mat, and a second illumination unit And a latching portion for latching the insertion portion so that the insertion mat can swing about the first end portion, and an original provided on the second illumination portion. A positioning portion having an opening into which the first protrusion is tightly inserted when the mat rotates in a direction approaching the second illumination portion about the first end portion, and the second illumination portion is provided with the first end. Holding the second end facing the part so that it can be opened with the first protrusion inserted into the opening of the positioning part An image reading apparatus.
[Selection] Figure 1

Description

  The present invention relates to an image reading apparatus.

2. Description of the Related Art Conventionally, an image reading apparatus including a document cover that includes a light source for a transparent document is known. In the image reading apparatus disclosed in Japanese Patent Application Laid-Open No. 2004-228561, a document mat for blocking a light emitted from a light source for a transmissive document and bringing the reflected document into close contact with the document table is mounted on the document cover for reading the reflected document. For reading, the original mat is removed from the original cover.
In order to recognize an area of a reflective original placed at an arbitrary position in the reading area in the image reading apparatus, it is necessary to completely cover the reading area with an original mat whose surface has a high reflectance. Further, in order to store the document within the depth of field of the optical system, it is desirable that the reflective document is completely in close contact with the document table in the reading area. In particular, since the edge portion of the document is likely to warp, it is desirable that the document mat is in close contact with the document table in the vicinity of the end surface of the document guide for positioning the reflective document on the document table.

  However, when the document mat is detachable as disclosed in Patent Document 1, the document mat cannot be accurately positioned on the document cover without sacrificing ease of detachment, so that the document mat runs on the document guide. Thus, the original mat must be positioned. Then, a gap is formed between the original mat and the original table at the reading area origin. In such a state, it is impossible to prevent the edge of the reflection document from being lifted off the surface of the document table, and thus the edge of the reflection document cannot be read clearly.

JP 2003-75944 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading apparatus that allows a user to easily attach and remove a detachable document mat to an accurate position.

(1) An image reading apparatus for achieving the above object includes a transparent document table, a first illumination unit provided below the document table to illuminate the document table, and provided below the document table. A reading unit for reading a document placed on the document table; a second illumination unit provided above the document table for illuminating the document table; a plate-shaped document mat for covering the document table; and the document An insertion portion provided at the first end of the mat, a first protrusion provided at the first end of the original mat and projecting in the thickness direction of the original mat, and provided at the second illumination portion A latching portion that has an opening into which the insertion portion is loosely inserted and that holds the insertion portion so that the original mat can swing about the first end portion; and the second illumination portion And the second matte is arranged so that the original mat is substantially centered on the first end. A positioning portion having an opening into which the first protrusion is inserted when rotated in a direction approaching the portion, and a second end portion provided on the second illumination portion and facing the first end portion of the original mat And a holding part that holds the first projecting part in a state where the first projecting part is inserted into the opening of the positioning part.
Since the latching portion has an opening into which the insertion portion of the original mat is loosely inserted, the user can easily insert the insertion portion of the original mat into the opening of the latching portion. When the original mat latched by the latching portion rotates in the direction approaching the second illumination unit with the first end portion substantially at the center, the first protrusion is tightly inserted into the opening of the positioning unit. In this state, the holding portion holds the second end portion facing the first end portion of the original mat so as to be openable. As a result, the original mat is accurately positioned and held at a predetermined position of the second illumination unit in a removable state.

(2) The image reading apparatus may further include a main housing to which the document table is fixed. The second illumination unit may be rotatably connected to the main housing. The latching portion is provided in the vicinity of the rotation axis of the second illumination unit, and the insertion portion is arranged so that the rotation axis of the second illumination unit and the first end portion of the original mat are parallel to each other. The part may be hung.
In a configuration in which the rotation axis of the second illumination unit and the rotation axis of the original mat are parallel and the rotation axis of the original mat is close to the rotation axis of the second illumination unit, the user holds the original mat on the second illumination unit. It can be easily hooked to the part.

(3) The image reading device includes a second protrusion that is provided at a portion of the first end of the original mat that is spaced from the first protrusion, and protrudes in the thickness direction of the original mat, and the second When the original mat is rotated in a direction approaching the second illumination unit with the first end portion substantially at the center, the document mat is perpendicular to the arrangement direction of the first projection and the second projection. And a rotation restricting portion having an opening into which the second protrusion is inserted loosely in an arrangement direction of the first protrusion and the second protrusion.
An opening is provided in the second illuminating unit so that the second projection provided in a portion separated from the first projection of the original mat is inserted in a direction perpendicular to the arrangement direction of the first projection and the second projection. Thus, the rotation around the first protrusion of the original mat can be restricted. In the configuration in which the second protrusion is loosely inserted into the opening in the arrangement direction of the first protrusion and the second protrusion, the tolerance of the distance between the first protrusion and the second protrusion can be set large.

(4) In the image reading apparatus, the original mat is in close contact with the original table at the reading area origin of the reading unit, and the first protrusion has a corner portion closest to the reading area origin of the original mat. It may be formed in the vicinity.
In the configuration in which the first protrusion is formed in the vicinity of the corner closest to the reading area origin of the original mat, the position tolerance of the first protrusion with respect to the reading area origin can be reduced.

Embodiments of the present invention will be described below based on a plurality of examples. In each of the embodiments, the constituent elements having the same reference numerals correspond to the constituent elements of the other embodiments having the reference numerals.
(First Example)
(1) Configuration FIG. 1 is a schematic diagram showing the structure of an image scanner 1 as a first embodiment of an image reading apparatus according to the present invention. The image scanner 1 is an image reading apparatus having a flat bed type having a document table 16 made of a transparent glass plate and having a contact image sensor.

  The document table 16 is formed of a transparent plate such as a glass plate, and a transparent document and a reflective document are placed on the board surface. The transparent original is a developed photographic film such as a strip film or a mount film. The transparent document may be placed on the document table 16 while being locked to a holder (not shown), or may be placed on the document table 16 as it is. The document table 16 is fixed to the document guide 302 of the main housing 300.

  The main carriage 24 includes a reflection original illumination unit 22, a selfoc lens array (SLA) 18, and a linear image sensor 20. The main carriage 24 is supported on the sub carriage 35 by a spring 34. The main carriage 24 comes into close contact with the document table 16 by being pushed by the spring 34. Therefore, the SLA 18 and the linear image sensor 20 mounted on the main carriage 24 are accurately positioned in the optical axis direction. The ring 44 fixed to the sub-carriage 35 slides along the guide rod 36 installed in the sub-scanning direction. The subcarriage 35 is coupled to a pulley 38 and a belt 42 hung on the pulley 46. The pulley 38 is driven by a motor 40. When the motor 40 rotates, the main carriage 24 together with the sub carriage 35 moves along the document table 16 in the sub scanning direction.

The SLA 18 is fixed to the main carriage 24 in such a posture that the arrangement direction of the SELFOC lens coincides with the main scanning direction. The SLA 18 forms an erecting equal-magnification image of the reflective original 48 on the light receiving surface of the linear image sensor 20.
The linear image sensor 20 as a reading unit is fixed immediately below the SLA 18 of the main carriage 24 in such a posture that the arrangement direction of the photoelectric conversion elements coincides with the main scanning direction. The linear image sensor 20 includes a photoelectric conversion unit including a large number of photodiodes and a charge transfer unit such as a CCD or a CMOS.

  The reflective document illuminating unit 22 as the first illuminating unit includes a light guide, an LED, and the like, and is fixed in the vicinity of the SLA 18 of the main carriage 24 so that the longitudinal direction of the light guide coincides with the main scanning direction. .

  The sub-housing 100 accommodates the transmissive original illumination unit 26 and is connected to the main housing 300 so as to be rotatable from a posture in which the plate surface of the document table 16 is opened by a hinge (not shown) to a posture in which the plate surface of the document table 16 is covered. The transmissive original illumination unit 26 includes a fluorescent tube, a light guide, and the like. The sub housing 100 and the transparent document illumination unit 26 correspond to a second illumination unit.

  The original mat 200 is detachably attached to the sub housing 100. The original mat 200 is for bringing the original placed on the surface of the original table 16 into close contact with the original table 16. The original mat 200 is attached to the sub-housing 100 when the reflective original 48 is read, and is removed when the transparent original such as a film is read.

FIG. 2 is a block diagram showing an electrical configuration of the image scanner 1.
The CPU 64 executes a control program stored in the ROM 66 and controls each part of the image scanner 1. The ROM 66 is a non-volatile memory that stores a control program. The RAM 70 is a memory that temporarily stores a control program, scanned image data, and the like. The RAM controller 68 controls data transfer among the CPU 64, the AFE unit 76, the image processing unit 74, the external interface 72, and the RAM 70.

The reflection document light source 50 such as an LED is turned on and off by a light source controller 52 including an inverter circuit, a control circuit, and the like. The reflection original light source 50 and the light source controller 52 correspond to a first illumination unit.
The light source 54 for a transparent document such as a fluorescent tube is controlled to be turned on and off by a light source controller 56 including an inverter circuit, a control circuit, and the like. The light source 54 for transmissive document and the light source controller 56 correspond to a second illumination unit.

The linear image sensor 20 is controlled by a sensor controller 58 that outputs control pulse signals such as a gate pulse signal and a shift pulse signal.
The motor 40 that moves the main carriage 24 in the sub-scanning direction is controlled by a sub-scanning controller 62 that outputs control pulses.

  The analog front end (AFE) unit 76 performs CDS (Correlated Double Sampling) processing, optical black clamp control for reproducing the black level of the image, level adjustment processing of the electric signal by adjusting the gain of the electric signal of the image, Scan image data digitized by performing quantization processing or the like is stored in the RAM 70 via the RAM controller 68.

  The image processing unit 74 is a DSP (Digital Signal Processor) that performs signal processing for performing image processing such as gamma correction and shading correction on the scanned image data stored in the RAM 70 in cooperation with the CPU 64. The external interface 72 connects the image scanner 1 and an external system such as a PC so that they can communicate with each other.

  FIG. 3 is a perspective view showing a state in which the original mat 200 is mounted on the sub housing 100. Two insertion portions 204 are provided on the first end portion 208 of the original mat 200 so as to be separated from each other. The vicinity of a specific side when the original mat 200 is viewed as a rectangle is referred to as an end. The lower surface 201 of the original mat 200 is white. The lower surface 201 of the original mat 200 is wide enough to completely cover the reading area of the original table 16.

  FIG. 4 is a perspective view showing the sub-housing 100 with the original mat 200 removed. The transparent document illumination unit 26 is provided at a position covered by the document mat 200. The arrangement direction of the openings 104 of the two latching portions is parallel to the rotation axis of the sub housing 100. The opening 102 of the positioning part and the opening 106 of the rotation restricting part are provided in the vicinity of the opening 104 of the latching part. The opening 102 of the positioning part is circular. The opening 106 of the rotation restricting portion is an ellipse that is long in the direction of the rotation axis of the sub housing 100 (the arrangement direction of the opening 102 of the positioning portion and the opening 106 of the rotation restricting portion).

5 is an enlarged view of a latching portion of the sub-housing 100, FIG. 6 is an enlarged view of an insertion portion of the original mat 200, and FIG. 7 is a hanging state of the sub-housing 100 in a state where the original mat 200 is mounted on the sub-housing 100. It is sectional drawing of a stop part.
The opening 104 of the latching portion is configured so that the insertion portion 204 can be loosely inserted. The opening 104 is surrounded by the wall surface of the sub housing 100. A cavity 107 surrounded by the wall surface of the sub housing 100 is formed inside the opening 104. The cavity 107 is configured to accommodate the insertion part 204. The latching portion is configured by the opening 104, the cavity 107, and the wall surface of the sub-housing 100 surrounding the opening 104 and the cavity 107.

  The first protrusion 202 is provided at the first end 208 of the original mat 200 where the insertion portion 204 is provided. The position where the first protrusion 202 is provided is in the vicinity of the corner of the original mat 200 that is closest to the reading area origin of the original table 16 when the original mat 200 is placed on the original table 16. The first protrusion 202 is formed in a substantially cylindrical shape and protrudes in the plate thickness direction of the original mat 200. The diameter of the first protrusion 202 is substantially the same as the diameter of the opening 102 of the positioning part. When the first protrusion 202 is inserted into the opening 102 of the positioning part, the side wall surface of the first protrusion 202 and the opening of the positioning part The outer wall surface of the sub housing 100 that surrounds 102 is set in a pressure contact relationship. In order to facilitate the insertion of the positioning portion into the opening 102, it is desirable to chamfer the corner portion of the first protrusion 202.

The second protrusion 206 (see FIG. 1) is provided at a position spaced from the first protrusion 202 of the first end 208 of the original mat 200. The shape of the second protrusion 206 is substantially the same as that of the first protrusion 202. Since the opening 106 of the rotation restricting portion is an ellipse as described above, the second protrusion 206 is tight in the direction perpendicular to the arrangement direction of the first protrusion 202 and the second protrusion 206. The second protrusion 206 is loosely inserted in the direction of arrangement of the second protrusion 206 into the opening 106 of the rotation restricting portion. Such dimension setting is such that even if the distance between the first protrusion 202 and the second protrusion 206 and the distance between the opening 102 of the positioning part and the opening 106 of the rotation restricting part are shifted during molding, the opening of the rotation restricting part This is because the second protrusion 206 can be surely inserted into 106 and the original mat 200 does not rotate around the first protrusion 202.
The configuration of the image scanner 1 has been described above.

(2) Mounting of Document Mat Next, mounting of the document mat 200 will be described.
First, as shown in FIGS. 8 and 9, the insertion portion 204 of the original mat 200 is inserted into the opening 104 of the latching portion of the sub-housing 100. This operation is performed in a state where the sub-housing 100 is rotated upward and separated from the main housing 300 as shown in FIG. Since the opening 104 of the latching portion is configured so that the insertion portion 204 can be inserted loosely, the user can easily insert the insertion portion 204 of the original mat 200 into the opening 104 of the latching portion. Further, since the opening 104 of the latching portion is formed in the vicinity of the rotation axis A of the sub-housing 100, the user can easily insert the original mat 200 into the opening 104 of the latching portion of the sub-housing 100.
When the insertion portion 204 of the original mat 200 is inserted into the opening 104 of the latching portion of the sub-housing 100, the insertion portion 204 is latched by the wall surface of the sub-housing 100 while being accommodated in the cavity 107 of the latching portion. It is done.

  Next, when the original mat 200 rotates in a direction approaching the sub-housing 100 about the first end 208, the first protrusion 202 is tightly inserted into the opening 102 of the positioning portion as shown in FIG. The second protrusion 206 is tight in the direction perpendicular to the arrangement direction of the first protrusion 202 and the second protrusion 206, and is loose in the arrangement direction of the first protrusion 202 and the second protrusion 206. Inserted into. Further, the second end 210 of the original mat 200 is held by the holding unit 108. As a result, the movement (parallel movement and rotation) parallel to the lower surface 201 of the original mat 200 is completely restricted, and the original mat 200 is accurately positioned with respect to the sub housing 100.

  When the sub-housing 100 rotates downward (see FIG. 10A) and the original mat 200 is placed on the original table 16, the original mat 200 is placed on the original guide 302 as shown in FIG. The entire lower surface 201 of the original mat 200 is in close contact with the original table 16 without being laid. Since the original mat 200 can be accurately positioned in the sub-housing 100, the tolerance of the width W3 from the reading area origin to the edge of the original mat 200, and the tolerance of the width W1 from the original guide 302 to the edge of the original mat 200, Can be estimated small. As a result, the distance W2 from the document guide 302 to the reading area origin can be set small. In addition, since the entire lower surface 201 of the original mat 200 can be brought into close contact with the original table 16, it is possible to prevent the original from floating from the original table 16 in the reading area. Therefore, the document can be positioned within the shallow depth of field of the SLA 18.

(Other examples)
As shown in FIGS. 11A and 11B, only one insertion portion 204 may be provided at the first end portion 208 of the original mat 200.

The schematic diagram which concerns on the Example of this invention. The block diagram which concerns on the Example of this invention. The perspective view which concerns on the Example of this invention. The perspective view which concerns on the Example of this invention. The perspective view which concerns on the Example of this invention. The perspective view which concerns on the Example of this invention. Sectional drawing which concerns on the Example of this invention. The perspective view which concerns on the Example of this invention. Sectional drawing which concerns on the Example of this invention. The schematic diagram which concerns on the Example of this invention. The perspective view which concerns on the Example of this invention.

Explanation of symbols

1: image scanner (image reading device), 16: document table, 20: linear image sensor (reading unit), 22: reflection original illumination unit (first illumination unit), 24: main carriage, 26: transmission original illumination unit ( (Second illumination unit), 100: sub-housing (second illumination unit), 102: opening of the positioning unit, 104: opening of the latching unit, 106: opening of the rotation restricting unit, 108: holding unit, 200: original mat, 202: First protrusion, 204: Insertion part, 206: Second protrusion, 208: First end part, 210: Second end part, 300: Main housing

Claims (4)

A transparent platen,
A first illuminator provided below the document table for illuminating the document table;
A reading unit that is provided below the document table and reads a document placed on the document table;
A second illumination unit provided above the document table and illuminating the document table;
A plate-shaped document mat for covering the document table;
An insertion portion provided at a first end of the original mat;
A first protrusion provided at the first end of the original mat and protruding in the thickness direction of the original mat;
A latching portion that is provided in the second illuminating portion and has an opening into which the insertion portion is loosely inserted, and the document mat latches the insertion portion so as to be swingable about the first end portion. When,
A positioning portion provided in the second illumination portion, and having an opening into which the first protrusion is tightly inserted when the original mat rotates in a direction approaching the second illumination portion with the first end portion as a center. When,
A holding provided in the second illuminating unit and releasably holding a second end facing the first end of the original mat in a state where the first protrusion is inserted into the opening of the positioning unit. And
An image reading apparatus comprising: A main housing to which the document table is fixed;
The second illumination unit is rotatably connected to the main housing,
The latching portion is provided in the vicinity of the rotation axis of the second illumination unit, and the insertion portion is arranged so that the rotation axis of the second illumination unit and the first end portion of the original mat are parallel to each other. The image reading device according to claim 1, wherein the image reading device is configured to hang the portion. A second protrusion that is provided in a part of the first end of the original mat that is spaced from the first protrusion and protrudes in the thickness direction of the original mat;
An arrangement direction of the first protrusion and the second protrusion when the original mat is provided in the second illumination part and rotates in a direction approaching the second illumination part with the first end portion substantially as a center. A rotation restricting portion having an opening into which the second protrusion is inserted loosely in an arrangement direction of the first protrusion and the second protrusion,
The image reading apparatus according to claim 1, further comprising: The original mat is in close contact with the original table at the reading area origin of the reading unit,
The image reading apparatus according to claim 1, wherein the first protrusion is formed in the vicinity of a corner closest to the reading area origin of the original mat.

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