JP2662019B2 - Image reading device - Google Patents

Description

Description: 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 in which lines are formed in a main scanning direction on a read original from an illumination unit in order to form a plate collection mask. Irradiation of illumination light to obtain density information of the passage holes, and when reading image information carried on the transmissive original via the same illuminating portion, forming a light transmissive portion corresponding to the reading range of the transmissive original The present invention relates to an image reading apparatus which uses a light-shielding member made in this way, thereby preventing flare light or the like from being generated and enabling a highly accurate image reading operation.

BACKGROUND OF THE INVENTION For example, in the field of printing and plate making, an image scanning reading and reproducing system for electrically processing image information carried on an original to create a film original for the purpose of streamlining work processes, improving image quality, etc. Is widely used.

The image scanning reading and reproducing system basically includes an image reading device and an image reproducing device. In this case, the image reading apparatus illuminates the reflection type or transmission type document conveyed in the sub-scanning direction in the main scanning direction by using the irradiating means, reads the reflected light or transmitted light by the image reading means, and converts it into an electric signal. . On the other hand, the image reproducing apparatus performs arithmetic processing such as gradation correction and contour emphasis according to plate making conditions on the image information photoelectrically converted by the image reading apparatus, and records and reproduces the image on a record carrier such as a film. The record carrier is developed by a predetermined developing device and is used as a film original for printing or the like.

By the way, for example, plate collection and composition are performed to combine a pattern and a character or a pattern and a mark for creating a catalog, a pamphlet, and a flyer, and an image reading apparatus is employed for this type of plate collection and synthesis work. . This image reading apparatus uses a read original in which a reflective original cut out in advance is adhered to a transparent base, irradiates the read original with illumination light, and detects light passing through the read original via a line sensor. . Then, the density information of the passing light is read and 2
A negative output signal is obtained by performing a value conversion process, and a mask is created using this signal.

Therefore, it is conceivable to use the image reading apparatus for creating a mask as an image reading apparatus for a transmission type document constituting the above-described image scanning / reading / reproducing system.

In this case, in the image reading apparatus for making a mask, a long rod-shaped light source extending in the main scanning direction on the read document is used for the purpose of substantially improving the illumination efficiency and preventing the occurrence of uneven illumination. Is desired. However, in particular, if the long rod-like light source is used for a transmission type original such as a film whose size is considerably smaller than that of a read original for making a mask, a problem is caused.

That is, when this is schematically described with reference to FIG. 1, a bar-shaped light source 4 which extends in the main scanning direction (the direction of arrow B) corresponding to the size of a not-shown original for making a mask (not shown) is provided below the original table 2. Are arranged. Then, when the transmissive original 6 is placed on the original table 2 and the rod-shaped light source 4 is energized while the original table 2 is conveyed in the direction of arrow A in the sub-scanning direction, the transmitted light L ₀ transmitted through the transmissive original 6 is reduced. In addition, unnecessary light L ₀₁ , L ₀₂ having a relatively large light amount transmitted through the document table 2 is incident on the CCD camera 10 via the reflection mirror 8. For this reason, it has been pointed out that the unnecessary lights L ₀₁ and L ₀₂ become stray light such as flare light, so that the image reading operation of the transmissive original 6 cannot be performed with high accuracy.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-described disadvantages, and has a rod-shaped light source that irradiates illumination light in a line along a main scanning direction on a read document, and a transmission-type document. When reading, a light-blocking member is provided to prevent the illumination light from transmitting only through the reading range of the transmission type original and preventing unnecessary light from entering the CCD camera, thereby generating stray light such as flare light. It is an object of the present invention to provide an image reading apparatus capable of performing an image reading operation of the transmission type original with high accuracy without any trouble, and furthermore, by simply attaching and detaching a light shielding member, facilitating a handling operation. And

[Means for Achieving the Object] In order to achieve the above object, the present invention relates to a method in which the document placed on the document table is irradiated with illumination light linearly in the main scanning direction. An image reading apparatus that photoelectrically reads image information and / or density information of the document by being conveyed in a sub-scanning direction substantially orthogonal to a main scanning direction, and corresponds to a reading range of a transmission type document smaller in size than the document. A plate-like light-shielding member that has a light-passing opening that shields the illumination light emitted outside the reading range, and is detachable from the document table; and the transmission-type document and the light-shielding member. Positioning means for integrally positioning the document table with respect to the document table, wherein the positioning means is formed on a pin member provided on the document table, on the light shielding member, and the pin member is inserted therein. Holes, And a mount provided with a hole into which the pin member is inserted while the transmissive original is attached.

[Embodiment] Next, a preferred embodiment of the image reading apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 2, reference numeral 30 indicates an image reading apparatus according to the present embodiment. The image reading device 30 scans a document table 32 on which a document is set, a transport mechanism 34 for transporting the document table 32 in the direction of arrow A, and a document transported in the sub-scanning direction by the transport mechanism 34. It basically comprises an image reading unit 36. In this case, the transport mechanism 34 is a first housing
The image reading unit 36 is provided on the first housing 38 and is provided inside the second housing 40 mounted on the first housing 38. An opening 42 for passing the document table 32 is formed on one side surface of the second housing 40.

First, the transport mechanism 34 will be described. The first housing
Guide bars that are horizontal and parallel to each other on the upper surface of 38
44a and 44b are provided, and both ends of the guide bars 44a and 44b are supported by supports 46 and 48 on the first housing 38. Also, a ball screw parallel to the guide bars 44a and 44b
The ball screw 50 is rotatably driven by a driving motor 52 provided in the first housing 38, while the ball screw 50 is provided on the support bases 46 and 48.

Guide bars 44a, document C reading create masks to 44b, platen 32 which holds the transmission-type original S ₁ or reflection originals S ₂ carries image information is supported in a movable state. That is, as shown in FIGS. 2 and 3,
First pressing the lid and the base 54 and the reflection-type original S ₂ and the reading table glass 56 for placing a document C for openably to the base glass 56
58 includes a mask member 60 to be used in transmissive original S ₁ in the first presser lid 58 of Toko is placed a second presser lid 62.

A hollow portion 63 into which a prism described below is inserted is defined in the base 54, and the transmitted illumination light described below is used for the base glass.
Opening 64 for guiding the transmissive original S ₁ through 56 are defined. Further, pin members 66a and 66b are implanted on the upper surface of the end of the base 54 so as to be directed vertically upward. On the other hand, the first holding lid 58
Has a frame 70 having a substantially U-shaped cross section and a first light-transmitting plate, for example, a holding glass 72 sandwiched by the frame 70, and the frame 70 is provided with pin members 66a and 66b. Holes 74a and 74b for insertion are formed, and the pin members 66a and 66b are inserted.
Is selected to be larger than the thickness of the frame 70.

Further, the mask member 60 is made of light-shielding member substantially exhibits a lamellar, rectangular corresponding to a small reading range of the transmission type original S ₁ dimension than reflection originals S ₂ and the read original C at its center An opening 76 having a shape is formed. In addition, holes 78a and 78b are provided at one end of the mask member 60 in the short direction to engage the pin members 66a and 66b and perform the positioning and fixing functions of the mask member 60.

Next, the second holding lid 62 has a second light-transmitting plate body, for example, a holding glass 80, and rectangular bodies 82a and 82b made of a resin material are fixed to both ends in the longitudinal direction of the holding glass 80. At the same time, handles 83a and 83b are provided on the respective rectangular bodies 82a and 82b.

On the other hand, support stands 84a and 84b are erected on the first housing 38, and the hollow prism 85 is supported by the support stands 84a and 84b. An opening 86 extending in the main scanning direction (the direction of the arrow B) is defined at a predetermined position of the prism 85, and a transmission illumination means 88 is accommodated in the prism 85 below the opening 86. Is done. The transmitted illumination means 88 has a rod shape that is long in the main scanning direction. For example, fluorescent lamps, halogen lamps,
A light source 90 such as a xenon lamp;
A reflecting mirror 92 is provided below as necessary.

The reading angle β of the reading original C and the transmission type original S ₁ with respect to the virtual perpendicular line P is approximately
30 ° first transmissive illumination light L ₁ and the reflecting mirror 102 for reflecting the second transmissive illumination light L ₂ in the horizontal direction passing through are arranged. And the transmitted illumination light reflected in the horizontal direction.
_On the extension of L ₁ and L ₂ , there is provided a CCD as an image reading mechanism for reading these transmitted illumination lights L ₁ and L ₂ and reflected illumination light described later.
A camera 108 is provided.

The CCD camera 108 includes a casing 110 as shown in FIG. 2 and FIG.
And the second reading means 114 are provided. Further, the imaging lens 116 of the one end portion as an imaging optical system of the casing 110 is attached, the transmitted second transmitting illumination light L ₂ and the first transmitted through the imaging lens 116 in the casing 110 optical path switching means 118 for guiding the illumination light L ₁ and the reflected illumination light and (to be described later) to respective said first reading means 112 and the second reading means 114 is mounted.

The optical path switching means 118 has a reflection pair 120,
A rotation shaft 122 is engaged with one side of the rotation shaft 120. The rotating shaft 122
Is rotatably supported on a base 124, and one end of a swing plate 126 is engaged with an end of the rotating shaft 122. Base 12
An actuator, for example, a linear solenoid 128 is fixed on the side of the rocking plate 126 in close proximity to the rocking plate 126. Combine. Here, a coil spring 134 is externally provided on the rod 130, and when the linear solenoid 128 is deenergized, the rod 130 presses the rocking plate 126 via the resilient force of the coil spring 134. Thereby, the reflector 120 is oriented and held in the horizontal direction. on the other hand,
When the linear solenoid 128 is driven, the rod 130 is displaced inward, and the reflector 120 abuts against the stopper 136, so that the reflector 120 is positioned and held at an angle of 45 ° with respect to the vertical direction.

Above the reflector 120 line sensor constituting the first reading unit 112, for example, be arranged to CCD138 extends in parallel along the main scanning line of the transmission type original S _1.

The second reading unit 114 reads the original C and the reflective original S.
First and second reflecting mirrors 140a which are arranged corresponding to the main scanning line across the edges of the _2, comprises 140b, the reflection mirror 14
0a and 140b are positioned at an angle of 45 ° with respect to the vertical direction. A line sensor, for example, CCDs 142 and 144 is disposed above each of the reflection mirrors 140a and 140b. Furthermore, the first and second reflecting mirrors 140a, is CCD146 a line sensor as well is provided on the optical path of the first transmissive illumination light L ₁ and the reflected illumination light passes through the gap 140b. Therefore, a large document reading C and reflection originals S ₂ dimensions than transmissive original S ₁ is configured to read and divided through substantially three CCD142,144 and 146.

On the other hand, the second housing 40 in the reflection illumination means 150 for illuminating the reflected illumination light to be described later reflection originals S ₂ is provided. Light source 1 in this case, reflection illumination means 150 for outputting the reflected illumination light L ₃
52, a curved optical fiber bundle 158 formed by bundling a number of optical fibers 156 held at both ends by light guide holding members 154a and 154b, and reflected illumination guided by the optical fiber bundle 158. and a cylindrical rod lens 160 for condensing the light L ₃ in a line form.
At this time, the reflected illumination light L ₃ emitted from the holding member 154b
The position of the holding member 154b is selected in advance so that the illumination angle α formed by the virtual perpendicular line P perpendicular to the document table 32 is about 15 °. The reflected illumination light L collected by the rod lens 160
₃ after being reflected by the reflection originals S _2, via the reflecting mirror 102
The light enters the CCD camera 108. In this case, CCD camera 108 is disposed in the read via the reflecting mirror 102 reflecting the illumination light L ₃ to read angle β is reflected approximately 30 ° with respect to the virtual vertical line P position.

The image reading apparatus according to the present embodiment is basically configured as described above, and the operation and effect will be described next.

First, when performing the reading operation of the read original C in order to create a plate collection mask, the reflector 120 is displaced to a position shown by a two-dot chain in FIG. That is, the linear solenoid
By extinguishing 128, the rod 130 becomes a coil spring
The rod 130 protrudes outward through the elastic force of 134, and the rod 130 presses the rocking plate 126. For this reason, the rotating shaft 122 rotates, and the reflector 120 engaged with the rotating shaft 122 swings vertically upward by a predetermined angle to be positioned.

Then, after the first holding cover 58 of the document table 32 is opened and the read original C is placed on the base glass 56, the first holding cover 58 is closed and the holes 74a and 74b of the frame 70 are closed. The first holding lid 58 is fixed to the base 54 by fitting the pin members 66a and 66b. Then, the document table 32 is conveyed in the direction of arrow A under the action of the driving motor 52,
It is moved to a predetermined portion of the image reading unit 36.

When the document table 32 reaches a predetermined portion of the image reading section 36, the reading operation of the document C to be read is started. That is, the illumination light output from the light source 90 reaches the inside of the document table 32 from the opening 86 and irradiates the read document C in the main scanning direction (the direction of arrow B). This illuminating light transmits the read original through C as the first transmitted illuminating light L ₁ , and is guided to the second reading unit 114 in the CCD camera 108 via the reflecting mirror 102.

As shown in FIG. 4, in the second reading unit 114, the first transmissive illumination light L ₁ is divided into three parts, the first transmissive illumination light L ₁ from the main scanning line across the edges of the read document C first And the second
The light is reflected vertically upward by the reflection mirrors 140a and 140b and CC
Guided to D142, D144. The first transmissive illumination light L ₁ from the main scanning line middle portion of the read document C is directly applied to the CCD146. Thus, CCD142,144 and 146 first transmissive illumination light L ₁ through is converted photoelectrically predetermined image density signal is obtained, it feeds sent to an output unit (not shown) the image density signals by binarization Then, a plate-collecting mask (not shown) is prepared.
During this time, since the document table 32 is being conveyed in the sub-scanning direction (the direction of arrow A) under the action of the driving motor 52, the read document C is two-dimensionally scanned and all the image information is read. After the reading operation is completed, the driving motor 52
Is rotated in the opposite direction to that described above to move the document table 32 to a predetermined position.

On the other hand, the reading operations of the image information carried by reflection originals S ₂ is carried out in substantially the same manner as document C reading described above. That is, after placing a reflective original S ₂ removed document C reading by lid opening the first presser lid 58 of the platen 32 to the base glass 56, for closing off the first holding lid 58. Next, the document table 32 is
It is transferred to a predetermined portion of 36, and the reflection illumination means 150 is driven.
Accordingly, the reflected illumination light L ₃ emitted from the light source 152, after passing through the optical fiber bundle 158 is focused by a rod lens 160, it is guided to the platen 32. Then, the reflected illumination light L ₃ is taken out as an optical signal of image information by irradiating a reflection originals S ₂ via the presser glass 72 in the main scanning direction (arrow B direction). The image information as the optical signal is reflected by the holding glass 72 in an oblique direction, and then guided to the second reading unit 114 in the CCD camera 108 via the reflection mirror 102. Therefore, CCD14
All image information in the main scanning direction of the reflective original S2 is photoelectrically read via ₂ , 144 and 146. During this time,
Since the document table 32 is transported in the sub-scanning direction (direction of arrow A) under the action of drive motor 52, the reflection originals S ₂ is two-dimensionally scanned by the reflected illumination light L _3, the image information Will be taken out.

Furthermore, when reading a transmissive document S _1, after removal of the reflection originals S ₂ the first presser lid 58 of the platen 32 and the lid opening and lid opening said first presser lid 58. Next, the pin members 66a, 66b
A hole portion 78a, while placing the mask member 60 on the presser glass 72 through 78b, to place the transmission original S ₁ in the opening 76 formed in the mask member 60. At that time, a transparent manuscript
S ₁ is attached to the backing sheet 180, holes 182a are formed in said mount 180, 182b of the pin member 66a, the transmissive original S ₁ fitted to 66b positioned against base 54 . further,
A positioning mark (not shown) is provided on the mount 180 or the mask member 60, and a second pressing cover 62 is placed on the mask member 60 via the mark, and the pressing glass 80 of the second pressing lid 62 is sandwiching a transmissive original S ₁ by the presser glass 72 of the first presser lid 58.

Then, platen 32 under the action of the drive motor 52 reaches a predetermined portion of the image reading unit 36, the reading operation of the permeable supported image information on the original S ₁ is being started. That is, the illumination light outputted from the light source 90 is transmitted through the transmissive original S ₁ as the second transmissive illumination light L _2. In this case, after the second transmissive illumination light L ₂ is taken out as an optical signal of image information by transmitting the transmission document S _1, it passes through the image information holding glass 80 serving as the optical signal, by the reflection mirror 102 The light is reflected in the horizontal direction and guided to the CCD camera 108.

At this time, in the optical path switching means 118 in the CCD camera, the linear solenoid 128 is energized to displace the rod 130 inward against the elastic force of the coil spring 134.
Therefore, the pressing action on the swing plate 126 is released, and the reflector 1
20 oscillates vertically downward due to its own weight, and the stopper 136
The reflector 120 is positioned at an angle of 45 ° with respect to the vertical direction. Thus, the second transmissive illumination light L ₂ is transmitted through the imaging lens 116 reflector led to the CCD camera 108 side 120
And the light is reflected vertically upward by the reflector 120. As a result, the second transmitted illumination light L ₂ is transmitted to the first reading unit 11.
It is read photoelectrically via the CCD138 which is 2.

During this time, the document table 32 is conveyed in the sub-scanning direction (direction of arrow A) under the action of the driving motor 52. Consequently, the transmission type original S ₁ is irradiated by the second transmissive illumination light L ₂ in two dimensions, so that the image information is read by CCD138 is taken out.

In this case, according to the present embodiment, in order to perform the reading operation of the density information of the read original C with high accuracy, a long rod-like light source 90 is used in the main scanning direction (the direction of the arrow B), and the transmission type having a small size is used. when performing the read operations original S ₁ is placing the mask member 60 made of a light-shielding member on the first presser lid 58. Urging that case, the the mask member 60 forms an opening 76 corresponding to the reading range transmissive originals S _1, after positioning the transmissive original S ₁ in the opening 76, the light source 90 I do. Therefore, the unnecessary lights L ₀₁ and L ₀₂ shown in FIG. 1 are blocked by the mask member 60 and do not go out to the reflection mirror 102 side, and only the second transmitted illumination light L ₂ transmitted through the transmission type original S ₁ is used. Is a CCD camera 1
The incident light enters the inside of 08 (see Fig. 5). Therefore, CCD138
A can prevent the stray light flare light or the like is irradiated, the supported transmission type original S ₁ the image information can be read highly accurately effect.

Moreover, when performing read operations transmissive original S _1, may be performed the task of mounting the substantially mask member 60, the advantage that the preparatory work is simplified is obtained. Where the mask member
The hole 60 is provided with holes 78a and 78b.
The work of positioning the mask member can be achieved only by fitting the a and 78b to the pin members 66a and 66b, and the preparation work can be made more efficient.

The mask member 60 also has a function of preventing the pressing glass 72 from being damaged by the second pressing lid 62, in addition to the above-mentioned function as the light shielding means. The second holding lid 62 is provided with horns 82a and 82b made of a resin material at both ends in the longitudinal direction of the holding glass 80 to prevent the holding glass 72 from being damaged.

Further, in the image reading apparatus 30, the document reading C transmissive original S ₁ for creating a mask for collecting impression of a single light source 90
In this case, the illumination means can be substantially reduced. As a result, it is possible to achieve an effect that the entire image reading device 30 can be reduced in size and cost.

[Effects of the Invention] As described above, according to the present invention, a transmission type original having a small size is formed by using a long light source that irradiates a read original in a line in the main scanning direction in order to form a plate collection mask. The carried image information can be accurately read. In addition, it is only necessary to attach and detach the light-shielding member defining the opening substantially corresponding to the reading range of the transmissive original, thereby facilitating the entire preparation operation and performing an efficient and highly accurate image reading operation. The effect that becomes possible is obtained. Furthermore, a single light source can be used as illumination means for two types of originals, and there is an effect that the size and cost of the apparatus can be reduced.

As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to these embodiments, and various improvements and design changes can be made without departing from the gist of the present invention. Of course.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram when a transmissive original is read by an image reading apparatus according to the prior art, FIG. 2 is a schematic sectional view of the image reading apparatus according to the present invention, and FIG. FIG. 4 is an exploded perspective view of a platen, FIG. 4 is a schematic perspective explanatory view showing an internal configuration of a CCD camera constituting the image reading apparatus, and FIG. 5 is an explanation when a transmission type original is read by the image reading apparatus. FIG. 30 image reading device 32 document table 34 transport mechanism 36 image reading unit 58 lid lid 60 mask member 62 lid lid 76 opening 88 Transmission illumination means 90 Light source 102 Reflecting mirror 108 CCD camera 112 114 Reading means 116 Imaging lens 118 Optical path switching means 120 Reflector C Document to be read , S ₁ … Transparent original S ₂ … Reflective original

Claims (1)

(57) [Claims] An original placed on a platen is illuminated linearly in a main scanning direction with illumination light, and the platen is conveyed in a sub-scanning direction substantially orthogonal to the main scanning direction. What is claimed is: 1. An image reading apparatus for reading image information and / or density information photoelectrically, comprising: a light-passing opening corresponding to a reading range of a transmission-type original having a size smaller than that of the original; And a plate-shaped light-shielding member detachably attached to the document table while blocking the illumination light, and positioning means for integrally positioning the transmission-type document and the light-shielding member with respect to the document table. Wherein the positioning means includes a pin member provided on the document table, a hole formed in the light-shielding member, into which the pin member is inserted, and the transmissive document is adhered, The pin member is inserted Image reading device comprising a backing sheet having a hole that is, in that it comprises.