JPH05183692A - Copy moire prevention method and scanner with copy moire prevention mechanism - Google Patents

Abstract

PURPOSE:To prevent copy moire caused in an output picture by forming an image or an original picture at a position slightly before or after an image forming face of a CCD picture read sensor so as to read the original picture slightly unsharply. CONSTITUTION:A flat original platen 3 is moved upward or downward, and the flat original platen 3 is moved closely to a lens section 6 and a CCD picture read sensor section 7 or with an interval. An original is placed to the flat original platen 3 while a picture face of the original is directed downward and an optical image of the picture of the original 8 is formed to a position slightly in front or rear the position of the CCD picture read sensor 7 by b. Thus, the image of the original projected onto a face of the CCD picture read sensor 7 is slightly unsharpened in this manner to prevent occurrence of remarkable moire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing the occurrence of copy moire in a scanner device for receiving an image of an original document such as a printed matter whose gradation is reproduced by halftone dots by a CCD image reading sensor, and a copy method. The present invention relates to a scanner device having a mechanism for preventing moire.

[0002]

2. Description of the Related Art As shown in FIG. 6, a conventional scanner device equipped with a flat platen table reads an image of a document with a CCD image reading sensor and records and stores the read image signal in a memory means as an image database. Alternatively,
Computer, color printer via memory means,
Image output processing is performed by inputting to output means such as a CRT display.

The above-mentioned conventional scanner device has a structure as shown in FIG. 7, and a linear CCD image reading sensor is mounted inside, and an image of an original including halftone dots such as a printed matter is sensed by the image reading sensor. A visible image is output on a sheet such as output paper by an appropriate output means such as an electrostatic color copying machine using a toner system based on the received image by scanning, and the image can be copied.
The linear CCD image reading sensor is a unit pixel detection sensor having a specific size (for example, a minimum size of 20 μm square to 30 μm square, a maximum size of 200 μm square to 30 μm).
A large number of 0 m square CCD image receiving elements) are arranged in a regular area at a predetermined pitch corresponding to the size.

By the way, the pitch per unit length between the arrangement pitch of the unit pixel detection sensors (sensor arrangement spatial frequency) and the arrangement pitch of the dots included in the image of the copy original (image spatial frequency by the dots). The difference, or the pitch difference per unit length between the arrangement pitch of the unit pixel detection sensors and the output image scanning pitch of the electrostatic copying output means is, for example, about 0 to 5 pitch / mm, and the two are compared. In the case of the approximate value, the copied image output on the output paper has the arrangement pitch of the unit pixel detection sensors set to n / mm and the repeated image spatial frequency such as a halftone dot included in the original image is r. As shown by a general theoretical expression L = | n−r | of the number L of moire generated in a unit width (frequency unit is book / mm) in the case of times / mm, the pitch difference is That striped moire those liable to occur.

[0005]

As a measure for avoiding the occurrence of the above-mentioned moire, for example, the arrangement pitch of the CCD image reading sensor may be set to a pitch which is sufficiently fine with respect to the pitch of the halftone dots of the image to be copied. For example, it is possible to avoid the occurrence of moire.

However, when the array pitch of the unit pixel detection sensors of the CCD image reading sensor is made fine and the number of arrayed unit pixel detection sensors is increased, a huge memory capacity corresponding to the number is required. This may cause a memory shortage and may hinder the image reading processing efficiency.

According to the present invention, an image signal read from a document containing an image of a predetermined pitch by a CCD image reading sensor of a scanner device is used without changing the memory capacity.
It is an object of the present invention to avoid the occurrence of moire and enable the read image output means to output a copy.

[0008]

The first invention of the present invention is as follows:
A transparent flat platen table on which a document is placed closely, an openable top cover plate that covers the upper surface of the document table, a linear movable light source for illuminating the document, and a fixed optical lens including an optical lens unit. System and a scanner device equipped with a CCD image reading sensor installed at the original image focus position of the fixed optical lens system, the focused optical image of the original placed on the original table is transferred to the CCD image reading sensor. When a document copy image is output by the copy output means based on the received image signal, in the image forming optical system of the scanner device,
A method for preventing copy moire, characterized in that a lens portion of a fixed optical lens system and a flat platen table are brought close to or apart from each other, and a document image is formed by image formation slightly in front of or behind the CCD image reading sensor. Is.

A second aspect of the present invention is a transparent flat platen table on which a document is placed in close contact, an openable upper cover plate which covers the upper surface of the platen, and a linear for illuminating the document. A movable light source, a fixed optical lens system including an optical lens unit, and a CC installed at a document image focus position of the fixed optical lens system.
A flatbed scanner device having a D image reading sensor and outputting a document copy image by a copy output means based on an image signal received by the CCD image reading sensor of an imaged light image of a document placed on a document table. The imaging optical system is provided with a flat platen original table that can be moved up and down horizontally with respect to a horizontal frame of the apparatus main body, and the flat platen original table is provided so as to be able to approach or separate from the lens portion of the fixed optical lens system. A scanner device with a CCD copy moire prevention mechanism characterized by the above.

A third aspect of the present invention is a transparent flat platen table on which a document is placed in close contact, an openable upper cover plate which covers the upper surface of the platen, and a linear for illuminating the document. A movable light source, a fixed optical lens system including an optical lens unit, and a CC installed at a document image focus position of the fixed optical lens system.
A flatbed scanner device having a D image reading sensor and outputting a document copy image by a copy output means based on an image signal received by the CCD image reading sensor of an imaged light image of a document placed on a document table. In the imaging optical system, C
A scanner device with a CCD copy moire prevention mechanism, characterized in that a CD image reading sensor is provided so as to be close to or away from the lens portion of the fixed optical lens system.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the copy moire prevention method according to the first aspect of the present invention will be described in detail according to the embodiment of FIG. 1. FIG. 1 shows a scanner device used in the embodiment of the method of the present invention. 2 is a perspective view for explaining the outline of the above, a horizontal transparent flat platen table 3, a light source unit 5 that moves along the lower side in the arrow direction, and a lens unit 6 at a fixed position below the light source unit 5.
And a linear CCD image reading sensor section 7 (a sensor in which unit pixel detection sensors are linearly arranged) below the lens section 6 and horizontally interlocking with the lens section 6 in phase symmetry with respect to the lens section 6 The flat platen original table 3 is moved toward or away from the lens unit 6 and the CCD image reading sensor unit 7 by using the scanner device having the above.

The flat platen table 3 is provided with appropriate means.
By moving up or down, the flat platen table 3 is moved toward or away from the lens section 6 (lens focal length; f) and the CCD image reading sensor section 7, and the document is copied on the flat platen table 3. The image surface of the original 8 is placed in close contact with the image surface facing downward, and the optical image of the image of the original 8 (image of desired frequency such as halftone dot image and line drawing image) is slightly Δb from the position of the CCD image reading sensor 7. An image in which the CCD image reading sensor 7 avoids the occurrence of conspicuous moire by slightly blurring the formed image of the original image projected on the image receiving surface of the CCD image reading sensor 7 at the front or rear position. It is designed to be read as a signal.

The position of the flat platen table 3 in the ascending / descending direction can be set by the following equation. That is, the position a _{1 of the} flat platen table 3 (distance between the flat platen table 3 and the lens portion 6) is set as follows: 1 / a ₁ + 1 / (b + Δb) = 1 / f Therefore, a ₁ = f (b + Δb ) / (B + Δb−f).

The copy moire prevention method according to the first aspect of the present invention will be described in detail with reference to another embodiment of FIG. 2. FIG. 2 shows a scanner device used in another embodiment of the method of the present invention. FIG. 3 is a perspective view for explaining the outline, including a horizontal transparent flat platen table 3, a light source unit 5 that moves along the lower side in the arrow direction, and a lens unit 6 at a fixed position below the light source unit 5. , A linear CCD below the lens portion 6 and horizontally interlocking with the lens portion 6 in phase symmetry with respect to the lens portion 6
By using a scanner device having an image reading sensor unit 7 (a sensor in which unit pixel detection sensors are linearly arranged), the lens unit 6 is brought close to the flat platen table 3 and the CCD image reading sensor unit 7. It is to move away from each other.

Another embodiment of the first invention (see FIG. 2).
In the above, the lens unit 6 is moved relative to the flat platen table 3 and the CCD lens unit 7. The original document 8 is placed on the flat platen table 3 with the image surface to be copied on the lower side, and is closely placed upside down. An optical image of a desired frequency such as a dot image or a line drawing image) is formed at the front or rear position slightly Δb from the position of the CCD image reading sensor 7 and projected on the image receiving surface of the CCD image reading sensor 7. After slightly blurring the formed image of the original,
The CD image reading sensor 7 reads the image signal as an image signal that avoids the occurrence of noticeable moire.

The position of the lens portion 6 can be set by the following equation. That is, the setting of the position a ₁ (distance between the platen platen 3 and the lens unit 6) of the lens unit 6 (lens focal length; f) is 1 / a ₁ + 1 / (b + Δb) = 1 / f Therefore, a ₁ = f (b + Δb) / (b + Δb−f).

FIG. 3 is a schematic side view for explaining an embodiment of the apparatus according to the second aspect of the present invention. It is vertically slid along the guide 30 above the horizontal frame 2 above the apparatus main body frame 1. A movably transparent flat platen table 3 is provided in a horizontal state. The flat platen table 3 includes a transparent glass plate 12 mounted and supported in a frame body 11 having a rectangular shape in a plane. Square corner portions 11a, 11 of the frame body 11
Vertical support shafts 1 are provided on the lower side of a, 11a, and 11a, respectively.
3, 3, 13, 13 are attached and the frame body 11 is supported horizontally.

The horizontal frame 2 of the main body of the apparatus includes a shaft portion 20.
a, 20a is provided with a rotating body 20 rotatably supported in a vertical direction, and four vertical supporting shafts 13 are respectively screwed with male screws 13a of the same phase. 13 is screwed to a female screw 20b that is vertically screwed in the rotating body 20.

A sprocket 21 is provided on the outer periphery of each rotating body 20 at the upper stage thereof, and the sprocket 21 is wound by an endless chain 15 and can rotate in conjunction.
Further, one of the rotating bodies 20 is provided with a gear 22 at a lower stage thereof, and meshes with a drive gear 23 which is axially supported by a drive shaft 16a of an electric motor (servo motor, pulse motor, etc.).

The other of the rotary bodies 20 is similarly provided with a gear 22 at the lower stage thereof, a driven gear 24 meshing with the gear 22, and a rotary support shaft 24a integrally attached to the driven gear 24. A rotary encoder 17 for detecting the rotation phase position is arranged in the position.

Inside the apparatus main body frame 1, there is provided a light source section 5 for illuminating the lower surface of the original 8 which is turned upside down and placed in close contact with the upper surface of the glass plate 12 of the flat original table 3, and the light source section 5 is provided. Is a linear type visible light (or visible light including an ultraviolet light region), which can be moved linearly below the flat platen table 3 horizontally at a predetermined speed from right to left in the drawing of FIG. is there. Reference numeral 4 is an opaque upper cover plate whose back surface is covered with the upper surface of the original 8 which is placed on the upper surface of the glass plate 12 with the image to be copied on the lower surface and turned upside down.

A light source section 5 inside the apparatus main body frame 1 is also provided.
A lens portion 6 of a fixed optical lens system is provided in the lower central portion, and below the lens portion 6, in synchronization with the light source portion 5 in the same phase relationship, horizontally linearly in the arrow direction. A linear CCD image reading sensor 7 capable of moving is arranged.

In the embodiment of the second aspect of the invention (see FIG. 3), the flat platen table 3 which moves up and down with respect to the horizontal frame 2 of the apparatus main body is turned upside down and placed in close contact. The image plane on which the image to be copied of the original 8 is imaged via the lens portion 6 is positioned slightly forward or slightly behind the linear CCD image reading sensor 7. The flat platen table 3 is lowered or raised to appropriately approach or separate from the lens portion 6 for positioning.

The ascending / descending operation of the flat platen table 3 is performed by the electric motor 16, the drive gear 23 is rotated by the motor 16, and the gear 2 meshing with the drive gear 23 is used.
The rotator 21 is rotated in the forward direction or the reverse direction via the sprocket 21 and the sprocket 21 integrated therewith is rotated, and all the rotators 20, 20 are passed through the endless chain 15 wound around the sprocket 21. , 20 and 20 are interlocked with each other, and vertically supported shafts 13 are respectively screwed onto the shafts.
By extending or shortening the horizontal platen 2 from the horizontal frame 2, the flat platen platen 3 integrated therewith is moved up and down.

The ascending / descending position of the flat platen table 3 is detected by the rotary encoder 17 which meshes with the gear 22 of the rotator 20 and rotates in conjunction with each other, and a position setting signal of the flat platen table 3 is output to perform predetermined positioning. Is used for. It should be noted that the lifting means for the vertical support shaft 13 is not limited to the above structure. or,
The vertical support shaft 13 is a square corner portion 11 of the platen platen 3.
The structure does not necessarily need to be integrally attached to the lower side of a, and may have a structure in which it is simply supported by contact.

Next, the apparatus according to another embodiment of the second invention will be described in detail with reference to FIG. 4, in which a transparent flat platen table 3 is horizontally placed above the horizontal frame 2 above the apparatus main body frame 1. Prepare for the condition. The flat platen table 3 includes a transparent glass plate 12 mounted and supported in a frame body 11 having a rectangular shape in a plane. Below the square corners 11a, 11a, 11a, 11a of the frame body 11, one end of each of the four vertical support shafts 13, 13, 13, 13 is screwed with male and female screws of the same phase. Wear the frame frame 1
Support 1 horizontally.

Each of the vertical support shafts 13 is rotatably supported vertically with respect to the horizontal frame 2 of the apparatus main body,
Moreover, the sprocket 14 is pivotally supported. Each sprocket 14 is wound by an endless chain 15 and can rotate in an interlocking manner. Further, one of the vertical support shafts 13 is provided with a gear 18 at the lower stage of the sprocket 14, and a drive gear 19 axially supported by a drive shaft 16a of an electric motor (servo motor, pulse motor, etc.).
Meshes with.

The other of the rotating bodies 20 is similarly provided with a gear 18 at the lower stage thereof, a driven gear 17a meshing with the gear 18, and a rotary support shaft 17b integrally attached to the driven gear 17. Arranges a rotary encoder 17 for detecting the rotational phase position.

Inside the apparatus main body frame 1, there is provided a light source section 5 for illuminating the lower surface of the original 8 which is turned upside down and placed in close contact with the upper surface of the glass plate 12 of the flat original plate 3 from below. Is a linear type visible light (or visible light including an ultraviolet light region), which can be linearly moved horizontally below the flat platen table 3 at a predetermined speed from right to left in the drawing of FIG. is there. Reference numeral 4 is an opaque upper cover plate whose back surface is covered with the upper surface of the original 8 which is placed on the upper surface of the glass plate 12 with the image to be copied on the lower surface and turned upside down.

Further, the light source section 5 inside the apparatus main body frame 1
A lens portion 6 of a fixed optical lens system is provided in the lower central portion, and a point-symmetrical position below the lens portion 6 with the lens portion 6 in the same phase relationship as the light source portion 5, A linear CCD image reading sensor 7 that is capable of moving linearly horizontally in the direction of the arrow in synchronization is arranged.

Another embodiment of the second invention (see FIG. 4)
In FIG. 1, the image to be copied of the original 8 which is placed upside down on the upper surface of the glass plate 12 of the flat platen table 3 that moves up and down with respect to the horizontal frame 2 of the apparatus body is imaged through the lens section 6. The flat platen table 3 is lowered or raised so that the image forming surface is positioned slightly front side or slightly rearward with respect to the linear CCD image reading sensor 7 and the lens unit 6 is moved. Then, the positioning is performed by appropriately approaching or separating.

The flat platen platen 3 is moved up and down by an electric motor 16, a drive gear 19 is rotated by the motor 16, and a gear 18 meshing with the drive gear 19 is used.
The vertical support shaft 13 is rotated in the forward or reverse direction via the sprocket 14 to rotate the sprocket 14, and four vertical support shafts are respectively provided via the endless chain 15 wound around the sprocket 14. 13 is rotated in the same direction, and the flat platen table 3 horizontally supported by screwing on one end side of the vertical support shaft 13 is attached to the horizontal frame 2
To move up and down.

The ascending / descending position of the platen platen 3 is detected by the rotary encoder 17 which is engaged with the gear 18 of the vertical support shaft 13 and rotates in conjunction with the platen platen 3 to output a position setting signal for predetermined positioning. Is used for.

In the second invention, the case where the linear CCD image reading sensor 7 is used as the CCD image reading sensor has been described as an example, but the present invention is not limited to this, 3, it is also possible to use, for example, an area type CCD image reading sensor fixedly installed in a region including the image forming surface on the optical axis of the lens unit 6 shown in FIG.

In the second invention (see FIGS. 3 and 4), the flat platen table 3 is moved relative to the lens section 6 and the CCD image reading sensor section 7. The position can be set by the following equation, as in the first embodiment of the first invention (see FIG. 1) described above. For example, when the flat platen table 3 is moved up or down, the optical image of the image of the document 8 is changed to CC
The CCD image reading sensor 7 is formed by forming an image in the front or rear position slightly Δb from the position of the D image reading sensor 7.
When it is desired to obscure the read image due to, and to avoid the occurrence of a noticeable moire, the position of the flat platen table 3 (distance a ₁ between the flat platen table 3 and the lens portion 6) is set to 1 / a ₁ +1. / (b + Δb) = 1 / f Thus, a _{a 1 = f (b + Δb} ) / (b + Δb-f).

Next, the apparatus of the third embodiment of the present invention will be described in detail with reference to FIG. 5. FIG. 5 is a perspective view for explaining the outline of the apparatus of the first embodiment, which is a horizontal flat plate. An optical lens arranged between a document table 3 (a flat platen table that is movable up and down with respect to the apparatus main body frame in the second invention or is a fixed type different from the second invention) and the CCD image reading sensor 7. The position of the lens unit 6 in the system is made movable in the optical lens system. In addition, a is a lens portion 6 from the upper surface of the glass plate of the flat platen table 3.
Shows the distance to the lens center, and b shows the distance from the lens unit 6 to the CCD image reading sensor 7.

In FIG. 5, the lens portion 6 is fixed to the lens jig 25, and the jig arms 2 on both the left and right sides of the jig 25 are provided.
5a and 25a have the same phase vertical screw shafts 28 and 2
Screw 8 on. One end of each of the vertical screw shafts 28 is pivotally supported by the fixed frame 26, and the other end thereof is pivotally supported by the bearing portions 27a, 27a of the support arms 27, 27 provided upright on the fixed frame 26. The vertical screw shafts 28, 28 respectively include a sprocket 28a and a gear 28b.
Is mounted and fixed, and is pivotally supported. The sprocket 28
An endless chain 28c is wound around a and 28a so that both vertical screw shafts 28 and 28 can rotate together.

The gear 28b pivotally supported on one of the vertical screw shafts 28 is meshed with a drive gear 30a pivotally supported on the drive shaft of an electric motor 30 (pulse motor, servo motor, etc.), and the other vertical screw shaft 28a. A driven gear 29a is meshed with a gear 28b pivotally supported by 28, and a rotary encoder 29 is connected to a support shaft portion 29b that pivotally supports the driven gear 29a.

The vertical screw shafts 28, 28 are interlocked with each other by the electric motor 30 to rotate the vertical screw shafts 28.
By moving up and down the lens jig 25 that is screwed onto the lens jig 8, the lens portion 6 attached to the lens jig 25 is fixed to the flat platen original plate 3 and the linear CCD image reading sensor 7 by a fixed optical lens system. In the above, the approaching or separating operation is performed. The confirmation of the position of the lens unit 6 is detected by the rotary encoder 29.

The light source section 5 and the linear CCD image reading sensor 7 linearly move in parallel to the flat platen table 3 in the same manner as in the second aspect of the invention, and have the same phase at the point-symmetrical positions. It moves according to the relationship.

Also in the third invention, as the CCD image reading sensor, in addition to the linear CCD image reading sensor 7, for example, it is fixedly installed in a region including the image forming surface on the optical axis of the lens portion 6. It is also possible to use an area CCD image reading sensor (a sensor in which a large number of pixel detection sensors are regularly arranged in the vertical and horizontal directions).

In the above third invention (see FIG. 5),
The lens unit 6 is used for the flat platen table 3 and the CCD lens unit 7.
The position of the lens portion 6 can be set by the following equation, as in the other embodiment (see FIG. 2) of the first invention described above. For example, by moving the position of the lens unit 6, the optical image of the original image is formed at the position slightly ahead or behind the position of the CCD image reading sensor 7 by Δb, and the CCD image is formed.
When it is desired to blur the image read by the image reading sensor 7 to avoid the occurrence of moire, the position of the lens unit 6 (focal length of the lens; f) (the platen platen 3 and the lens unit 6).
The setting of the separation distance a ₁ ) between and is: 1 / a ₁ + 1 / (b + Δb) = 1 / f Therefore, a ₁ = f (b + Δb) / (b + Δb-f).

[0043]

According to the method of the present invention, a document image is formed slightly in front of or behind the reading image receiving surface of the CCD image reading sensor of the scanner device, and then the original image is read by the CCD image reading sensor. Based on the read image signal, the copied image output means visually outputs the copied image, and the reproducibility of an image (predetermined frequency image) such as sharp halftone dots and lines included in the original image. Pixels (such as halftone dots and streak lines) that can be scanned with a slight unsharpness that does not affect (density, gradation, sharpness) Pixel) Pitch (Image spatial frequency value)
And the array pitch (array spatial frequency value) of the pixel detection sensors arrayed in the CCD image reading sensor, or the array pitch (array spatial frequency value) of the pixel detection sensors arrayed in the CCD image reading sensor And a striped moire generated on the copied visible image due to a pitch difference between the output scanning pitch of the copy output means and the unsharp image reading by the CCD image reading sensor, making it inconspicuous. Therefore, it is possible to prevent the occurrence of visible copy moire.

Further, in the scanner device of the present invention, the flat platen table or the lens portion is provided in the fixed optical lens system so that the position can be moved, and the flat platen table or the lens portion is moved to an appropriate position to set the CCD. An optical image of the original image is formed slightly in front of or behind the image receiving surface of the image reading sensor, and the image is read with a slight unsharpness that does not affect the reproducibility (density, gradation, sharpness). Therefore, the striped moire generated in the output image can be obscured by the read slightly unsharp image reading signal, and the occurrence of visible moire can be prevented.

[0045]

According to the copy moire prevention method and the scanner device with the copy moire prevention mechanism of the present invention, a document image is formed slightly in front of or behind the image receiving surface of the CCD image reading sensor mounted in the scanner device. By making the image slightly unsharp for reading, copy moire generated in the output image by the copy image output unit connected to the scanner device is prevented, and the arrangement pitch of the unit pixel detection sensors arranged in the CCD image reading sensor. Without increasing the number of arrayed unit pixel detection sensors or increasing the memory capacity in response to the increase in the number of sensors, and does not cause moire in document image reading using the scanner device in the printing plate making process. No image database, improvement of image reading / reading processing efficiency, and scanner It is intended to exert a remarkable effect in downsizing the location.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating an embodiment of a copy moire prevention method according to the first aspect of the present invention.

FIG. 2 is a perspective view illustrating another embodiment of the copy moire prevention method according to the first aspect of the present invention.

FIG. 3 is a side sectional view illustrating an embodiment of a scanner device with a copy moire prevention mechanism according to a second aspect of the invention.

FIG. 4 is a side sectional view for explaining another embodiment of the scanner device with the copy moire prevention mechanism in the second invention of the present invention.

FIG. 5 is a perspective view illustrating an embodiment of a scanner device with a copy moire prevention mechanism according to a third aspect of the invention.

FIG. 6 is a block diagram illustrating an outline of a conventional scanner device and copy output means.

FIG. 7 is a schematic side view illustrating the structure of a conventional scanner device.

[Explanation of symbols]

1 ... Device main frame 2 ... Horizontal frame 2a ... Space part 3 ... Flat platen table 4 ... Top cover plate 5 ... Light source part 6 ... Lens part 7 ... CCD image reading sensor 8 ... Original document 11 ... Frame frame body 12 ... Transparent glass plate 13 ... Vertical support shaft 14 ... Sprocket 15 ... Endless chain 16 ... Electric motor 16a ... Motor shaft 17 ... Rotary encoder 17a ... Spindle 1
8 ... Gear 19 ... Drive gear 20 ... Rotating body 21 ... Sprocket 22 ... Gear 23 ... Drive gear 24 ... Followed gear 25 ... Lens jig 25a ... Jig arm 26 ... Fixed frame 27 ... Support arm 27a ... Bearing part 28 ... Vertical Screw shaft 28a ... Sprocket 28b ... Gear 28c
… Endless chain 29… Rotary encoder
29a ... driven gear 29 b ... shaft 30 ... electric motor 30a ... driving gear a ... document - inter-lens distance a ₁ ... a document after movement adjustment - lens distance b ... between lenses -CCD image reading sensor distance [Delta] b ... sensor receiving surface - Distance between image planes

Claims (5)

[Claims] 1. A transparent flat platen table on which a document is placed in close contact,
An openable cover plate that covers the upper surface of the document table, a linear movement type light source for illuminating the document, a fixed optical lens system having an optical lens unit, and a document image focus position of the fixed optical lens system. The image forming optical image of the original placed on the original table is received by the CCD image reading sensor by using the scanner device having the CCD image reading sensor installed in the image forming apparatus, and the image is copied based on the received image signal. When outputting a document copy image by the output means, in the image forming optical system of the scanner device, the lens portion of the fixed optical lens system and the platen platen are brought close to or apart from each other, and the document is located slightly in front of or behind the CCD image reading sensor. A copy moire prevention method characterized in that an image is formed and received. 2. A transparent flat platen table on which a document is placed in close contact,
An openable cover plate that covers the upper surface of the document table, a linear movement type light source for illuminating the document, a fixed optical lens system having an optical lens unit, and a document image focus position of the fixed optical lens system. Equipped with a CCD image reading sensor installed in
An image forming optical system of a flatbed scanner device for outputting a document copy image by a copy output means based on an image signal received by the CCD image reading sensor of an imaged light image of a document placed on a platen. A copy moire comprising a flat platen table which can be moved up and down horizontally with respect to a horizontal frame of the main body, and the flat platen table is provided so as to be able to approach or separate from the lens portion of the fixed optical lens system. Scanner device with prevention mechanism. 3. A flat platen plate is horizontally provided so as to be vertically slidable with respect to a horizontal frame of the main body of the apparatus, and is supported by a horizontal frame of the main body of the apparatus so as to be capable of being driven up and down. 3. A vertical support shaft for connection or contact support on the subordinate side is provided, and the flat platen table is moved toward or away from the lens part of the fixed optical lens system by raising or lowering the horizontal support shaft. Scanner device with copy moire prevention mechanism. 4. A flat platen plate is horizontally provided with respect to a horizontal frame of an apparatus main body so as to be vertically slidable, and is rotatably supported by a horizontal frame of the main body of the device and has a flat platen plate at its square corners. A vertical support screw shaft screwed and supported on the subordinate side is provided, and the flat document table is moved toward or away from the lens portion of the fixed optical lens system by forward or reverse rotation of the vertical support screw shaft. 2. A scanner device with a copy moire prevention mechanism according to 2. 5. A transparent flat platen table on which a document is placed in close contact,
An openable cover plate that covers the upper surface of the document table, a linear moving light source for illuminating the document, a fixed optical lens system having an optical lens unit, and a document image focus position of the fixed optical lens system. Equipped with a CCD image reading sensor installed in
In the image forming optical system of the flatbed scanner device, which outputs a copy image of the document by the copy output means based on the image signal received by the CCD image reading sensor of the imaged light image of the document placed on the document table, the CCD A scanner device with a copy moire prevention mechanism, wherein an image reading sensor is provided so as to be able to approach or separate from a lens portion of a fixed optical lens system.