JP3347586B2 - Transmission original irradiation device and 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 capable of reading both reflected light obtained by irradiating an original such as a book and a photograph and transmitted light obtained by irradiating an original such as a film. The present invention relates to a transparent document irradiating device for irradiating light for transmitted light.

[0002]

2. Description of the Related Art Conventionally, as an image reading apparatus of this type, in particular, a transparent original irradiating apparatus provided in the image reading apparatus is, for example, as shown in FIG. FIG. 8 is a schematic cross-sectional view showing the configuration of a transparent document irradiation apparatus according to the related art.

As shown in FIG. 1, a transmissive original irradiating apparatus 1 has a translucent plate 4 having a light diffusing function at a joint S of a lower cover 3 with a box-shaped frame formed by an upper cover 2 and a lower cover 3. Are bonded by welding or double-sided tape, and a light source 5 for scanning exposure is provided in the frame.

When reading a transparent original, the translucent plate 4 needs to irradiate a uniform amount of light over the entire reading range to the position being read on the original. It is provided because a translucent plate having a light diffusion action is required to cover.

The transmissive document irradiating device 1 is provided rotatably with respect to an apparatus main body 6 having an image reading means 8 therein, and a document table glass 7 provided on the apparatus main body 6 when reading an image. Is arranged such that the translucent plate 4 is arranged at a position opposed to.

[0006] The operation of reading an image by the image reading apparatus configured as described above will be briefly described below.

First, when reading a document image such as a film, the document is placed on a document table glass 7. Then, the light source 5 and the image reading means 8 are moved and scanned in synchronization with each other in the direction of the arrow in the figure, so that the original is irradiated from the light source 5 through the translucent plate 4 and the transmitted light is transmitted to the original platen glass 7. The image is read by being guided to the image reading means 8 through the image reading device.

When reading a document image such as a book or a photograph, the document is placed on a platen glass 7. The light source (not shown) arranged inside the apparatus main body 6 and the image reading means 8 are moved and scanned in synchronization with each other in the direction of the arrow in FIG. Is guided to the image reading means 8 via the platen glass 7, whereby the image is read.

[0009]

However, in the case of the above-described prior art, the following problems have occurred.

In such an image reading apparatus, when reading an image by reflected light, it is common to read an original image with the transmission original irradiating device mounted.

However, when a thick original such as a book is placed on the original placing glass and the transmissive original irradiator is closed by the reflected light (set at a predetermined position (position shown in FIG. 8)), the translucent plate is raised. Is pushed up. For this reason, addition is applied to the joint with the lower cover, and by repeating this, the joint is broken, or the translucent plate comes into contact with internal components such as the light source for scanning exposure, and the internal component or translucent plate is damaged. However, there is a problem in that the read image when reading the image by the transmitted light is adversely affected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide a method for reading an image of a thick original such as a book, which is adversely affected by the original. It is an object of the present invention to provide a transparent document irradiating apparatus and an image reading apparatus which are excellent in quality without any problem.

[0013]

In order to achieve the above object, according to the present invention, a substantially rectangular flat plate portion is provided.
A pair of at least one of substantially both ends provided
The side plate is made of a material that has light transmission and light diffusion functions.
A first cover integrally molded with a substantially rectangular flat plate portion;
And at least one of both ends of the flat plate portion.
A second cover provided with a pair of side plate portions;
Outer surfaces of a pair of side plates of the cover and the second cover
In order to have a predetermined minute gap between the inner surfaces of the pair of side plates
Face each other, and the inner surfaces of each flat plate face each other.
So that the first cover and the second cover are fixed
And a light source and the light source in the frame.
It is characterized in that scanning driving means for performing scanning driving is provided .

[0014]

[0015]

Therefore, a member for transmitting and diffusing the light from the light source and irradiating the original with the original forms a frame body as a flat plate portion including the optical path region and a first cover provided with a side plate portion. Therefore, the strength is excellent.

[0017] The ends of the pair of side plates of the first cover are turned outward by the tensile stress generated by pressing the plate of the first cover from the outside to the inside and bending the plate. It is preferable that the opening of the first cover is restricted at a predetermined position by the inner surfaces of the pair of side plates of the second cover so that the curved deformation of the flat plate of the first cover can be restricted to a predetermined amount.

Therefore, the flat portion of the first cover does not curve beyond a predetermined amount.

It is preferable to provide a rib for connecting at least one of the pair of side plates at a position on the flat plate of the first cover which does not obstruct the scanning optical path of the light source. Therefore, the rigidity of the first cover increases.

The image reading apparatus includes the above-mentioned transparent document irradiation device, a transparent document table, and image reading means provided on the opposite side of the transparent document irradiation device via the document table. It is preferable that the original placed on the document is scanned and exposed by the transparent original irradiating device, and the transmitted light is used to read the original image by the image reading means.

It is preferable that a reflection document irradiating means for scanning and exposing a document placed on the document table is provided on the same side of the document table as the image reading means.

Therefore, an original image can be read with both transmitted light and reflected light.

It is preferable that the transparent document irradiating device is supported so as to be substantially rotatable with respect to the document table.

The transparent original is provided by providing a mounting member rotatably supported on a mounting portion formed integrally with the side plate portion of the first cover as an axis, and mounting the mounting member to the document table. It is preferable that the irradiation device is substantially rotatable with respect to the document table.

[0025]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) FIGS. 1 to 5 show a transparent document irradiation apparatus and an image reading apparatus according to a first embodiment of the present invention.

FIG. 1 shows a schematic configuration of a transparent original irradiating apparatus and an image reading apparatus according to a first embodiment of the present invention.

In the figure, reference numeral 106 denotes an image sensor such as a CCD serving as a reading means, which is provided in the image reading apparatus main body 100. A document placing glass 101 as a document table is provided on the upper surface of the apparatus main body. The document P placed on the document placing glass 101 is scanned by an image scanning means 102 as an image reading means, and an image is exposed on the image sensor 106. . In the image sensor, three rows of sensors, each of which is equipped with RED, GREEN, and BLUE films, are arranged to read an image on a document by color separation. The image scanning unit 102 includes a lamp unit 103 and a mirror unit 104 that move and scan in parallel with the image mounting glass 101, and a lens 105 fixedly mounted in the apparatus main body 100.

A lamp unit 103 serving as a reflection original irradiating means includes a white light source L ₁ for illuminating the original P, and a _first mirror for reflecting the image reflected light of the original P illuminated by the light source L ₁ toward the mirror unit 104. Due to M ₁ , the mirror unit 104 turns the image light reflected by the first mirror M ₁ back toward the image sensor 106,
It is constituted by third mirrors M ₂ and M ₃ . The lamp unit 103 moves and scans at twice the speed of the mirror unit 104 in order to keep the optical path length constant in the entire image reading area. For this reason, the optical system of this configuration is usually called a 2: 1 optical system. These units scan (sub-scan) in synchronization with a reading cycle of the image sensor using a driving source (not shown) such as a pulse motor as power.

Reference numeral 200 denotes a transparent original irradiation device for reading a transparent original.
It is a light source unit as a device. L _TwoIs the light source L of the main body₁
The light source 201 is arranged in parallel to the
The half that has a light-diffusion effect and is provided at a position
It is a lower cover as a transparent first cover. Transparent manuscript
The reading light source unit is attached to the rear end of the image reading device,
It can be opened and closed with the hinge 202 as a fulcrum.

[0031] When reading the transparent original, the light source L ₂ is by a driving source (not shown), a range covering the platen glass 101, parallel to the lower cover 201 is scanned synchronously with the image scanning means 102 of the main body . In this case the light source L ₁ of the main body is turned off. Light from the light source L ₂ results in light distribution, such as shown in FIG. 1 (a) is diffused into the surface of the document in translucent plate 201. Of these, the light on the optical axis from the reading position of the image reading apparatus main body to the image sensor 106 is transmitted to the image sensor 106 through the original placed at the position P in the drawing.

When reading a transparent original, the range of the upper end A of the original platen glass is an area where the original is prohibited from being placed. Prior to reading the document, the image sensor reads the direct light amount and light distribution from the light source for the transparent document in this area, and sets the data as various correction data.

FIG. 2 schematically illustrates how an image on a document is formed on a light receiving portion of an image sensor. Around the light receiving portion of the image sensor, a portion that accumulates electric charges converted by the light receiving portion and a portion that transfers a signal to an output stage are adjacent to each other, so that the light receiving portions 106R (RED) of three colors are provided.
106G (GREEN) and 106B (BLUE) are arranged at intervals.

In order to read the same position of R, G, and B by moving the image sensor relative to the original, the interval between the light receiving sections is an integral multiple of the width of the light receiving sections. If there are m lines between RGs and n lines between GBs, the G image signal of a certain l line on the document corresponds to the m lines of the R image signal, and the B image signal corresponds to the (m + n) lines. Read late.

FIG. 3 is a block diagram of the read image data processing by the color image sensor. The image data of each color read by the image sensor 106 is sent to amplifiers 121R, 121G, and 121B, amplified, and then converted into digital image signals by A / D converters 122R, 122G, and 122B. Each A / D converter divides the dynamic range of the image sensor (the difference between the read output between the true white part and the true black part on the document) by the number of bits, and determines the number of gradations according to the brightness of the image on the document. assign. For example, when an A / D converter with a resolution of 8 bits is used, 256 gray levels can be identified from white to black, and 1024 gray levels can be identified for a 10-bit A / D converter. Therefore, RGB
In an image reading apparatus using an A / D converter of 8 bits for each color, 24 bits = about 16.7 million colors can be identified, and for 10 bits for each color, 30 bits = about 1.074 billion colors can be identified.

As described above, since the light receiving portions of each color of the image sensor are arranged at intervals, the phase is adjusted before the image signal is input to the image processing circuit 124.
Buffer memories 123R and 123G for (m + n) lines are provided downstream of the D converter 122R and n lines are provided downstream of the A / D converter 122G, and output is performed in accordance with the B signal read last. . The image processing circuit 124 outputs an image signal that has been subjected to color correction calculations, binarization processing, and the like.

The image signal is supplied to the interface circuit 12
5 to a device 300 such as a personal computer.

There are several types of image signal output modes of the image reading apparatus, and an output mode suitable for the use of the read image can be selected. When reading text and applying the content to OCR or when reading a monochrome line drawing, a monochrome binary image is suitable.
From the GB image signals, for example, a G signal is used, and image data obtained by binarizing the G signal at a certain threshold value by the image processing circuit 124 is selected. When reading an image such as a photograph and outputting the image to a monochrome printer, image data binarized using a halftone process such as a dither method or an error diffusion method using a G signal is also used. . When processing color images, multi-valued (24
bit etc. ) Image data is suitable.

As an A / D converter used in an image reading device, a device having a resolution equivalent to the image processing capability of a connected computer is often used (an image reading device for a computer capable of processing a 24-bit image). RG
An 8-bit A / D converter for each color is used, but an A / D converter having a higher resolution than the processing capability of a computer is used in order to obtain a higher definition gradation. Such an image reading apparatus, for example, each of RGB 10
In the case of using a bit A / D converter, each color 10
The signal divided into gradation levels of bits is converted into 8 bits for each color by the image processing circuit and output.

The transparent original reading light source unit 200 as a transparent original irradiating apparatus, which is a feature of the first embodiment of the present invention, will be described in more detail with reference to FIGS.

Reference numeral 200 denotes a transparent original reading light source unit body, in which a transparent original irradiating light source L ₂ , a motor serving as a driving source constituting scanning driving means for scanning the light, and a motor comprising a gear train and a belt. Transmission means of rotation,
Further, a control circuit for receiving a signal from the image reading apparatus main body and generating a lighting signal of a light source and a driving signal of a motor in accordance with the signal is incorporated.

Reference numeral 203 denotes an upper cover as a second cover;
Reference numeral 201 denotes a lower cover as a first cover, and these constitute a frame.

The lower cover 201 is formed of a transparent material such as PC or acrylic, and a light diffusing agent such as metal oxide powder added thereto. Reference numeral 201a denotes a portion of the document placing glass for irradiating the document (scanning light path passing portion), 201b denotes an outer frame portion, which constitutes a flat plate portion, 201c denotes a hook portion to be attached to the main body, and 201d denotes a side plate portion. It is a side wall part.

FIG. 5A is a sectional view of the lower cover 201 assembled in the light source unit 200 for reading a transparent original. As shown in FIG.
d and the inner surface 203 of the side wall as the side plate of the upper cover
a is opposed with a predetermined minute gap δ.

When the light source unit 200 for reading a transparent original having the lower cover 201 of this configuration is closed on an image reading apparatus on which a thick original is placed, as shown in FIG. Sagging between. At this time, the side wall 201d tries to open outward as it goes, but is restricted by hitting the inner surface 203a of the side wall of the upper cover 203, and is prevented from opening further. As a result, a repulsive force against the document is generated from the lower cover 200, and the lower cover 200 is no longer bent.

As described above, since the lower cover 201 is integrally formed, the rigidity of the light irradiating portion and the outer frame portion is greatly improved as compared with the prior art, and the portion of the lower cover 201 where the document is irradiated (scanning light path) Since the bending deformation of the passage portion 201a can be regulated by a predetermined amount, the joint between the light irradiation portion and the outer frame portion is not broken as in the related art, and the quality does not contact the internal components. In addition to the improvement, the cost of the product can be significantly reduced by integrating the components.

Although the present embodiment has been described using a light source unit for reading a transparent original which scans a light source, a light source unit of a type in which a plurality of light sources are fixedly mounted and simultaneously illuminates the entire reading range. It is also possible to apply to.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention. The rigidity of the lower cover itself is further increased by providing ribs that connect between the side walls of the lower cover 201 in the first embodiment. For other configurations and actions, refer to
Therefore, the same components are denoted by the same reference numerals, and description thereof will be omitted.

[0049] 201e as shown in FIG, 201f are left and right, with ribs connecting the front and rear side walls, shades range can not be provided with ribs, such as the scanning range of the light source L ₂ are (does not interfere with the scanning beam path position )).

As a result, the rigidity of the lower cover 201 is improved, and the effect is further enhanced.

(Third Embodiment) FIG. 7 shows a third embodiment of the present invention. The other components are further integrally formed on the lower cover 201 in the first embodiment, and the lower cover 201 also functions as a substrate having other functions. Other configurations and operations are the same as those of the first embodiment, so that the same components are denoted by the same reference numerals and description thereof will be omitted.

As shown in the figure, a mounting portion 201g of a mounting leg portion 204 as a mounting member to the image reading apparatus main body 100 is provided integrally with the lower cover 201. A click 201i for holding the posture at the open position may be provided integrally.

[0053]

According to the present invention, since the surface of the frame body facing the platen is constituted by one member, the strength of the surface portion with respect to the frame body is increased, and the influence of external pressure on the document by the original is reduced. Excellent quality without being affected.

A member for transmitting and diffusing the light from the light source and irradiating the original with a document constitutes a frame as a first cover provided with a flat plate portion including the optical path region and a side plate portion. Therefore, it has excellent strength and is not adversely affected by external pressing by a document or the like.

Since the flat portion of the first cover is not bent more than a predetermined amount, the first cover does not come into contact with internal parts and the like, so that the quality is more excellent.

By providing the ribs on the flat portion of the first cover, the rigidity of the first cover is increased, and the quality is further improved.

As described above, it is possible to provide the image reading apparatus with a transparent original irradiating apparatus which is excellent in quality and is not adversely affected by external pressing by an original or the like.

Further, the above-mentioned transmission original irradiating device can be provided also in an image reading apparatus provided with a reflection original irradiating means and capable of reading an original image with both transmitted light and reflected light.

A mounting portion of a mounting member for supporting the transparent document irradiating device so as to be substantially rotatable with respect to the document table may be formed integrally with the side plate portion of the first cover.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a transparent document irradiation device and an image reading device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a state where an image on a document is formed on a light receiving unit of an image sensor.

FIG. 3 is a block diagram of read image data processing by a color image sensor.

FIG. 4 is a schematic configuration diagram of a transparent original irradiating apparatus which is a feature of the first embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view illustrating a state in which the transparent document irradiation device in FIG. 4 is attached to an image reading device.

FIG. 6 is a schematic configuration diagram of a transparent document irradiating apparatus which is a feature of the second embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a transparent original irradiating apparatus which is a feature of the third embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating a schematic configuration of a transmission original irradiation apparatus and an image reading apparatus according to the related art.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 Image reading apparatus main body 101 Document mounting glass 102 Image scanning means 106 Image sensor 200 Transparent document reading unit 201 Lower cover 201a Scanning light path passing section 201b Outer frame section 201d Side wall section 201e Rib 201f Rib 201g Mounting section 203 Upper cover 203a Side wall inner surface 204 mounting leg L ₂ transparent original reading light source

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 15/00 G03G 15/40 G03G 21/16-21/18 G03B 27/58-27/64 H04N 1 / 04-1/207

Claims (7)

(57) [Claims] 1. A substantially rectangular flat plate portion and a pair of side plate portions provided at substantially both ends of at least one of the flat plate portions are integrally formed of a material having a light transmitting and light diffusing function. A first cover, a substantially rectangular flat plate portion, and a second cover provided with a pair of side plate portions at substantially both ends of at least one of the flat plate portions.
And an outer surface of a pair of side plate portions of the first cover and an inner surface of a pair of side plate portions of the second cover are opposed to each other so as to have a predetermined minute gap, and each flat plate is A frame configured by fixing the first cover and the second cover so that the inner surfaces of the portions face each other, and a light source and a scan driving unit configured to scan and drive the light source in the frame. A transparent document irradiation device, comprising: 2. An end of a pair of side plates of the first cover due to a tensile stress generated by pressing the plate of the first cover from the outside to the inside and bending the plate. By restricting the opening toward the outside at a predetermined position by the inner surfaces of the pair of side plates of the second cover, the bending deformation of the flat plate of the first cover can be restricted to a predetermined amount. The transmission original irradiating apparatus according to claim 1 , wherein: To 3. A does not interfere with the scanning beam path of the light source at the flat portion of the first cover position, claim 1, characterized in that a rib for connecting at least one of the pair of the side plate portions, respectively Or the transmission original irradiating apparatus according to 2. 4. A transparent document irradiating apparatus according to claim 1 , a transparent document table, and an image reading means provided on the opposite side of said transparent document irradiating apparatus through said document table. An image reading device, comprising: scanning and exposing a document placed on the document table by the transparent document irradiation device, and reading the transmitted image by the image reading means. 5. A same side as the image reading means relative to the document table, according to claim 4, further comprising a reflective original irradiating means for scanning exposure original placed on the original table Image reading device. 6. The apparatus according to claim 1, wherein said transparent document irradiating device is supported substantially rotatably with respect to said document table.
6. The image reading device according to 4 or 5 . 7. A mounting member, which is rotatably supported on a mounting portion integrally formed on a side plate portion of the first cover as an axis, and the mounting member is mounted on the document table. 7. The image reading apparatus according to claim 6 , wherein the transmissive document irradiation device is substantially rotatable with respect to the document table.