JP3180046B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus, and more particularly, to an image reading apparatus having a plurality of resolutions and enabling a wide range of reading media.

[0002]

2. Description of the Related Art An image reading apparatus (hereinafter, referred to as a scanner) for reading character information and graphic information on a medium such as paper as image information has a flat plate for placing an original on a transparent flat plate and moving an optical unit to read the original. Bed scanners, ADF (auto document feed) scanners for automatically feeding and reading sheet-shaped documents, and handy scanners are generally known.

In these scanners, normal reading is set at a resolution of 200 dpi to 600 dpi. Further, when printing or enlargement is desired after reading, a high resolution of 1200 dpi to 1800 dpi is required. For this reason, widening the reading resolution of a scanner is an important theme.

To change the resolution, for example, 600 dp
By using an imaging lens for i and an imaging lens for 1200 dpi, by replacing each imaging lens with a desired resolution and switching the focal point, a scanner that can perform normal reading and high-resolution reading can be provided. providing.

[0005]

As described above, the conventional scanner has the following problems.

1) Since a plurality of imaging lenses are used and a mechanism for switching the imaging lenses is required, the operation of switching the resolution is troublesome, and the scanner becomes an expensive device.

[0007]

In order to solve the above problems, the present invention takes the following measures.

[0008] The focal point is switched in a plurality of stages using one imaging lens.

By taking the above means, an optical system corresponding to the reading resolution is formed, so that normal reading and high-resolution reading can be performed, and an optical system corresponding to the reading medium is formed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention adopts the following embodiments.

As shown in FIG. 1, the arrangement angle of a plurality of reflecting mirrors is changed to change the number of times of reflection of reflected light from a document.
It switches the distance to the imaging lens 6 from the original surface by changing the optical path of the reflected light from the original Te, the original
An optical path length switching means for switching the distance from the imaging lens 6 to the imaging plane of the CCD 7 in the direction on the optical path in association with the switched distance from the document surface to the imaging lens 6 is provided.

Furthermore, as shown in FIG. 2, the optical path length switch means, a distance from the original surface to the imaging lens 6 and the imaging
The distance from the lens 6 to the image plane of the CCD 7 is linked to each other
At least normal reading and high resolution reading and reading
Switch the optical path length in three stages , including reading far away from the surface
I can.

Furthermore, as shown in FIG. 3, the optical path length switch means, in conjunction with the distance switching operation to the arrangement angle switching operation and CCD7 image plane from the imaging lens 6 of the reflecting mirror when the optical path length switching operation Switch the optical path length.

Furthermore, as shown in FIG. 4, the image reading
The light source 51, the plurality of reflecting mirrors, and the imaging lens 56
If, to constitute the optical unit 61 having a CCD57, those
The optical unit 61 first reflects reflected light from the reading surface.
Isa first by mounting the frame <br/> over arm 71 pivotally reflecting mirror 53 parts as the rotation fulcrum 62 causes, from the optical unit 61
When reading the reading surface 52 which is arranged at a distance, the optical unit 61 is moved in a predetermined range using the rotation fulcrum 62 as a fulcrum.
The surface is scanned by rotating in a circle .

[0015] Then, as shown in FIGS. 3 to 5, before
The optical unit 61 includes a lever 17 that performs an optical path length switching operation, and a lever position detector 2 that detects the operation of the lever 17.
2a, 22b and one end of the fulcrum 62
A gear 64 to which rotational force is applied from a motor provided;
By the sensor provided on the frame at the other end of the rotation fulcrum 62
Rotation at a certain angle and home position of optical unit 61
The optical unit 6
When reading the reading surface 52 arranged apart from 1
Is detected by the lever position detector 22b.
The optical unit 61 is rotated in accordance with the information
A surface scan is performed while rotating in a predetermined range around 62 as a fulcrum.

By taking the above-described embodiment, the following operation works.

A desired resolution is obtained by changing the optical path length and switching the reading resolution.

Further, the reading resolution has three levels, for example, the normal resolution is set to 300 dpi level, the high resolution is set to 600 dpi or more, or 1200 to 1800 dpi for enlarged display or printout. When the reading range is wide, the resolution is about 75 dpi. Thus, in addition to the normal resolution, the resolution is increased when the image is to be displayed in an enlarged manner or when the user wants to print out the image.

Further, the optical path length switching operation can be easily performed.

Further, it is possible to widen the reading range and read a three-dimensional object. In addition, since it can form a two-dimensional image, it also has a function as a digital lamella.

Then, it is possible to easily read a wide range and a three-dimensional object.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A representative embodiment according to the present invention will be described with reference to FIGS. In the following, the same portions are denoted by the same reference numerals, and detailed description may be omitted.

FIG. 1 is a diagram illustrating the principle of the present invention.

In FIG. 1, light from a light source 1 is applied to a sheet 2
To the first reflecting mirror 3, the second reflecting mirror 4,
CCD 7 by the imaging lens 6 via the reflecting mirror 5
It is focused on and converted into image data.

Further, the first reflecting mirror 3 and the third reflecting mirror 5 are configured so that the arrangement angles can be changed in order to make the optical path variable. The light from the light source 1 is reflected on the sheet 2 and is focused on the CCD 7 by the imaging lens 6 via the first reflecting mirror 3 and the third reflecting mirror 5.

The distance between the image forming lens 6 and the image forming plane of the CCD 7 can be changed by a mechanism described later.

FIG. 2 is a diagram illustrating the principle of the present invention.

In the above configuration, the sensor pitch of the CCD 7 is a constant pitch set to a predetermined value. The resolution is determined by the ratio between the sensor pitch of the CCD 7 via the imaging lens 6 and the read width of the read original surface.

[0029] Thus, in the normal read, the distance from the original surface the distance to the imaging lens 6 from the imaging lens 6 When a ₁ to the imaging surface of the CCD7 becomes b _1. In high-resolution reading, when the distance from the document surface to the imaging lens 6 is a ₂ ,
The distance to the imaging plane of No. 7 is b ₂ . Further, when reading is performed with the reading surface being far away, the image forming lens
The distance to the When a ₃ distance from the imaging lens 6 to the imaging surface of the CCD7 becomes b _3.

FIG. 3 is a schematic view of an embodiment of the present invention (part 1).
It is.

FIG. 1 shows an example of a structure in which the optical path length is switched by interlocking the angular movement of the first and third reflecting mirrors and the distance movement of the imaging lens to the CCD.

The imaging lens 16 is disposed in an optical unit (not shown) so as to be movable in the optical path direction. Further, the imaging lens 16 is connected to the lever 17 via the connecting member 18.
The lever 17 is moved by being operated with the rotation fulcrum 20 as a fulcrum.

A stopper 21a and a stopper 21b are provided at the position where the lever 17 is operated, and a lever position detector 22a and a lever position detector 22b for detecting the operation position of the lever 17 are provided.

The lever 17 includes an arm a 26 and an arm b
27 are connected by 19 slots. The arm a26 and the arm b27 rotate around the rotation fulcrum 28 as a fulcrum.
The arm a26 and the arm b27 each have a long hole 36.
Arm a2.
6, a first reflecting mirror 33 is provided, and an arm b27 is provided with a third reflecting mirror.

The arm a 26 and the arm b 27 are attached to the elongated holes 19 and 36 by pins 37. Further, a detent spring 38 is provided at one end of the reflector support member 32 to maintain the movement angle of the reflector support member 32. Further, a stopper 21c and a stopper 21d for regulating the movement angle of the reflector support member 32 are provided.

In the above configuration, when the lever 17 is set at the position A, normal reading is performed. Also,
When the lever 17 is set at the position B, high-resolution reading is performed. Further, when the lever 17 is set at the position C, the reading is performed with the reading surface far away.

FIG. 4 is a schematic view of an embodiment of the present invention (part 2).
It is.

Referring to FIG. 5, a case where reading is performed with the reading surface being far away will be described. The optical unit 61 includes the lever 17 shown in FIG.
, A first reflecting mirror 53, a second reflecting mirror 54, a third reflecting mirror 55, an imaging lens 56, and a CCD 57. The optical unit 61 includes the first reflecting mirror 5.
The three parts are rotatably mounted on a frame 71 as a rotation fulcrum 62.

When reading the reading surface 52 which is arranged at a distance from the optical unit 61, the optical unit 61 is rotated in a predetermined range with the rotation fulcrum 62 as a fulcrum, and two-dimensional scanning is performed. This reading is suitable for reading a distant object or a three-dimensional object.

FIG. 5 is a schematic view of an embodiment of the present invention (part 3).
It is.

FIG. 3 shows a mechanism for rotating the optical unit 61 in conjunction with the lever position detector 22b shown in FIG. Rotary fulcrum 6 of optical unit 61
2 is rotatably mounted on the frame 71 by a support (not shown). The optical unit 61 is provided with a gear 64 at one end of a rotation fulcrum 62, and a torque is applied to the gear 64 from a motor 75 provided on the frame 71 via gears 72 a and 72 b.

An encoder 65 is provided at the other end of the rotation fulcrum 62. A sensor 76 provided on the frame 71 detects rotation at a fixed angle and the home position of the optical unit 61.

FIG. 6 is a flowchart (part 1) of the embodiment of the present invention.

Referring to FIG. 5, the operation procedure for high-resolution reading will be described.

In step S11, the lever position detector 22a determines whether the B position of the lever 17 has been detected.
If detected, the process proceeds to step S12. If not detected, the lever 17 is operated to the position B and the process returns to step S11.

In step S12, for example, in the case of an ADF scanner, a roller driving motor for automatic paper feeding is driven.

In step S13, a predetermined document is conveyed to the reading area, and the signal of the CCD is read to start reading.

In step S14, the reading of the CCD signal is stopped, and the reading of the predetermined document is completed.

In step S15, the motor is stopped, and the process ends.

FIG. 7 is a flowchart (part 2) of the embodiment of the present invention.

Referring to FIG. 5, an operation procedure in the case where reading is performed with the reading surface far away will be described.

In step S21, the lever position detector 22b determines whether the C position of the lever 17 has been detected.
If detected, the process proceeds to step S22. If not detected, the lever 17 is operated to the position C and the process returns to step S21.

In step S22, the motor 75 for rotating the entire optical unit is driven.

In step S23, the sensor 76 detects the rotational position of the encoder and determines whether the optical unit 61 is at the home position. If it is the home position, the process proceeds to step S24; otherwise, the process returns to step S23.

In step S24, the motor 75 is temporarily stopped at the home position.

In step S25, the motor 75 is driven, and reading is started in step S26.

In step S27, the sensor 76 detects the rotational position of the encoder, and determines whether the end position indicates that the optical unit 61 has rotated by a predetermined angle. If it is the end position, the process proceeds to step S28; otherwise, the process returns to step S27.

In step S28, the reading is terminated, and in step S29, the motor 75 is stopped and the processing is terminated.

The motor for driving the roller and the motor 75 for rotating the entire optical unit can be the same motor. For example, the rotation direction of the driving force is reversed,
Insert a one-way clutch into the transmission system.

On the other hand, the distance from the image forming lens to the image forming surface of the CCD may be such that the CCD can be moved in a direction on the optical path instead of the image forming lens.

[0061]

As described above, according to the present invention, the following effects can be obtained.

By changing the arrangement angle of the plurality of reflecting mirrors and changing the number of times of reflection of the reflected light from the original to change the optical path of the reflected light from the original, the distance from the original surface to the imaging lens is switched. From the original surface to the imaging lens
Since the optical path length switching means for switching the distance from the imaging lens to the CCD image plane in the direction on the optical path in association with the switched distance is provided, it is possible to obtain a desired resolution by switching the reading resolution. Therefore, various types of media can be read.

[0063] Further, the optical path length switch means, the document surface
From the lens to the imaging lens and CCD imaging from the imaging lens
At least normal reading in conjunction with the distance to the surface
And high-resolution reading and reading with the reading surface far away
The optical path length is switched in three stages , including the normal resolution. In addition to the normal resolution, high resolution is used when displaying an enlarged image or printing out, and the reading range is used when reading a wide area or reading a three-dimensional object. Can be read in a wide range.

[0064] Further, the optical path length switch means, the optical path length
Since the switching in conjunction with the distance switching operation to the CCD imaging surface from the arrangement angle switching operation and the imaging lens of the reflector during operation switching the optical path length can easily perform optical path length switch operation.

Further, the image reading device comprises an optical unit having a light source, a plurality of reflecting mirrors, an imaging lens, and a CCD, and the optical unit reflects light from a reading surface.
The first reflecting mirror for reflecting light first is pivotally mounted on the frame as a rotation fulcrum, and is separated from the optical unit.
When reading a reading surface arranged in a horizontal position , the optical unit is rotated in a predetermined range using the rotation fulcrum as a fulcrum to perform surface scanning, so that it is possible to widen the reading range and read a three-dimensional object. In addition, two-dimensional images can be formed. Furthermore, it is possible to have a function as a digital camera.

The optical unit includes a lever for performing an optical path length switching operation, a lever position detector for detecting the lever operation, and a module provided at one end of the rotation fulcrum on a frame.
Gears to which rotational force is applied from the
Rotation at a certain angle by a sensor provided on the frame at the end
Encoder that detects the home position of the optical unit
And a reader that is placed away from the optical unit
When scanning the surface, the lever operation position is detected as the lever position
The optical unit is rotated in accordance with the detection
Since the surface is scanned while rotating in a predetermined range with the point as a fulcrum, it is possible to easily read a wide range and a three-dimensional object.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a diagram illustrating the principle of the present invention.

FIG. 3 is a schematic diagram (part 1) of an embodiment of the present invention.

FIG. 4 is a schematic diagram (part 2) of the embodiment of the present invention.

FIG. 5 is a schematic diagram (part 3) of the embodiment of the present invention.

FIG. 6 is a flowchart (part 1) of the embodiment of the present invention.

FIG. 7 is a flowchart (part 2) of the embodiment of the present invention.

[Explanation of symbols]

 1, 51: light source 2: paper 3, 33, 53: first reflecting mirror 4, 54: second reflecting mirror 5, 34, 55: third reflecting mirror 6, 16, 56: imaging lens 7, 57: CCD 17: Lever 61: Optical unit 71: Frame 64: Gear 65: Encoder 75: Motor 76: Sensor

Claims (5)

(57) [Claims] An imaging lens (6) for changing the angle of reflection of a plurality of reflecting mirrors to change the number of times of reflection of reflected light from the original and changing the optical path of the reflected light from the original to change the optical path of the original from the original surface.
It switches the distance to the imaging from the original surface
An image characterized by comprising optical path length switching means for switching the distance from the imaging lens (6) to the imaging plane of the CCD (7) in the direction on the optical path in association with the switched distance to the lens (6). Reader. Wherein said optical path length switching means, forming from the original surface
Distance to imaging lens (6) and CC from imaging lens (6)
D (7) The distance to the image forming surface is linked to each other, and at least the normal reading, the high resolution reading, and the reading surface are far apart.
2. The image reading apparatus according to claim 1 , wherein the optical path length is switched to three stages including reading. Wherein the optical path length switch means, switching the optical path length
Distance switching Misao from arrangement angles switching operation and the imaging lens of the reflector during operation (6) to CCD (7) the imaging plane
By linking the work by switching the optical path length, that the image reading apparatus according to claim 1 or claim 2, characterized in. 4. An image reading apparatus comprising : a light source (51), a plurality of reflecting mirrors, an imaging lens (56), and a CCD (5).
7) and constitute an optical unit (61) with, the optical
Unit (61) reflects light reflected from the reading surface first
The first reflecting mirror (53) to be used is a rotation fulcrum (62).
By mounting rotatably Te Frame (71), an optical unit
The reading surface (52) arranged at a distance from the
When taken, the rotation fulcrum of the optical unit (61)
The image reading apparatus according to any one of claims 1 to 3, wherein the surface scanning is performed by rotating in a predetermined range using (62) as a fulcrum . Wherein said optical unit (61) includes a lever for performing optical path length switch operation (17), the lever position detector for detecting the lever (17) Operation and (22a, 22b), before
Is the motor provided on the frame at one end of the fulcrum (62)?
Gear (64) to which a rotational force is applied from the rotating fulcrum
(62) Constant by the sensor provided on the other end of the frame
Rotation of angle and home position of optical unit (61)
And an encoder (65) for detecting
The reading surface (52) placed away from the
When removing the lever (17), check the lever position
Optical unit in conjunction with the detection by the output unit (22b)
(61) is a predetermined range with the rotation fulcrum (62) as a fulcrum.
5. A surface scan is performed by rotating in a circle.
The image reading device according to claim 1.