JP2002023431A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader capable of accurately fixing an original, even in the case of reading a thick original, or even in the case of longitudinally placing the original. SOLUTION: As for the image reader which is provided with an original cover 6 which is opened/closed with reference to the device main body 1 and for reading the original D by a reading means, the reader is provided with a hinge member 7 for rotatably connecting the device main body 1 and the original cover 6, one end of the hinge member 7 and the device main body 1 are rotatably supported, and the other end of the hinge member 7 and the original cover 6 are rotatably supported, and the hinge member 7 is energized in an original cover 6 opening direction and also in a rotary shaft direction by a torsion compression coil spring 14.

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 for reading and outputting a manuscript such as a photograph or a document, and accurately fixing the manuscript even when a thick manuscript is read or placed vertically. The present invention relates to an image reading device capable of reading by reading.

[0002]

2. Description of the Related Art Image reading apparatuses such as scanners have been widely used with the spread of personal computers. Among them, flat bed type image reading apparatuses have the advantage that they can read even books. There is.

FIG. 6 is a schematic diagram illustrating the configuration of a conventional flatbed image reading apparatus. An original is placed downward on an original platen glass 51 disposed on the upper surface of an apparatus main body 50, and a contact image sensor 52 is attached to the original. Document information is optically read by scanning along a surface. At this time, the original is tightly fixed to the platen glass 51,
A document cover 53 is attached to the apparatus main body 50 so as to be openable and closable.

The document cover 53 is rotatably attached to the apparatus main body by a hinge portion 54 provided at the rear end of the apparatus, and a document pressing member 55 such as a sponge is attached to the inner surface side. Then, by placing the original on the original platen glass 51 and closing the original cover 53, the original is pressed and fixed to the original platen glass 51.

[0005]

The flat bed type image reading apparatus as described above requires an installation space equal to or larger than the document size, and is an apparatus capable of reading a large size document. Requires a large installation space.

However, since the contact image sensor is very small and lightweight, as shown in FIG. 7, the contact image sensor is vertically placed with one side down using an attached stand 56,
Some are enabled even in this state. Documents that can be scanned vertically are limited to sheet-like documents,
With the original cover and the tip of the device closed with a suction cup or the like, the original is pressed against the platen glass and scanned.

On the other hand, the original cover 53 in the configuration of the prior art
Opens and closes by turning around the hinge at the rear end,
In this method, a thick original such as a book cannot be pressed. Generally, the document cover 53 has another hinge or slides up and down to accommodate thick documents.

However, in such an image reading apparatus, if the above-described hinge structure is used, the hinge is opened when the document is placed vertically, and the document cover is lifted from the document glass so that the document cannot be pressed down. Hinge could not be used.

Further, a hinge member is provided between the document cover and the apparatus main body to form a two-stage hinge, and a function of restoring the positional relationship between the document cover and the hinge member when it is opened is added. Some documents can hold down the document firmly without opening the document cover during scanning, and can also handle thick documents even when scanning horizontally.

However, in the above image reading apparatus, the relationship between the original glass and the original cover when the original cover is closed due to the backlash in the rotation axis between the original cover and the hinge member is not constant. Occasionally, the original moved easily, and the function of fixing the original could not be sufficiently satisfied.

The present invention has been made to solve the above problems, and
An object of the present invention is to provide an image reading apparatus capable of accurately fixing a document even when a thick document is read or placed vertically.

[0012]

A typical configuration according to the present invention for achieving the above object is an image reading apparatus that has a cover member that can be opened and closed with respect to an apparatus main body and reads an original by reading means. A hinge member for rotatably connecting the device main body and the cover member, rotatably supporting one end of the hinge member and the device main body, and the other end of the hinge member and a cover member. Are pivotally supported so that the cover member is urged in a direction to open the cover member with respect to the hinge member by an urging means, and is urged in a rotation axis direction.

In the above configuration, when a thick original such as a book is set, the cover is rotated by a pivot portion between the hinge member and the apparatus main body and a pivot portion between the hinge member and the cover member. Will cover thick manuscripts. On the other hand, when a thin original is set, the support portion of the apparatus main body and the hinge member rotate, and the cover member urged in the opening direction by the urging means rotates integrally with the hinge member. It comes into close contact with the manuscript.

When the cover is placed vertically, the cover member is easily rotated in the direction in which the cover member closes with respect to the hinge member. However, the posture is maintained by the urging means, so that the document can be accurately pressed. Further, since the cover member is urged in the axial direction of the shaft supporting portion with the hinge member by the urging means, no rattling occurs.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the image reading apparatus of the present invention will be described with reference to FIGS.

(Overall Configuration) FIGS. 1A and 1B are schematic views of the configuration of a color image forming apparatus according to this embodiment. FIG. 1A is a partially cut plan view, FIG. 1B is a partially cut front view, and FIG. It is an explanatory side view.
As shown in the figure, an original is set on an original platen glass 2 attached to the upper surface of an apparatus main body 1, and an image described on the original is scanned by scanning a contact image sensor 3 in parallel with the original platen glass 2. read.

As shown in FIG. 2, the contact image sensor 3 includes three color LEDs 3R, 3G, 3B, which are light sources for illuminating the original, and reflects light reflected from the original on a light receiving element of the image sensor. A rod lens array 3L and an image sensor 3S are formed.
The three color light sources are sequentially switched and turned on, and the image sensor reads the reflected light from the document for each color to perform color separation reading.

The contact image sensor 3 is shown in FIG.
As shown in the figure, the guide shaft 4 fixed to the apparatus body
It is fixed and supported on a slider 5 that slides on it. A belt for transmitting power from a motor serving as a scanning drive source is fixed to the slider 5. The forward / reverse rotation of the motor enables the contact image sensor to perform reciprocal scanning in the range of the platen glass.

The components of the image reading apparatus include an electrical unit including a control board and a power supply in addition to the above. These components are arranged in the apparatus main body 1 which fixedly supports the platen glass.

An original cover 6 as a cover member for pressing the original onto the glass is placed on the original platen glass 2.
Is attached to the apparatus main body 1 via a hinge member 7 so as to be openable and closable. An original cover sheet 8 made of a sheet material and a sponge is attached to a surface of the inner surface of the original cover facing the original platen glass 2.

FIG. 3 is a block diagram of the read image data processing by the image reading apparatus. An image output signal read by the image sensor 3 in synchronization with the sequentially blinking LED is sent to the amplifier 9 and amplified, and then converted into a digital image signal by the A / D converter 10. A / D converter 10
Divides the dynamic range of the image sensor 3S (the read output difference between the pure white part and the pure black part on the original) by the number of bits and assigns the number of gradations according to the brightness of the image on the original. For example, when an A / D converter with a resolution of 8 bits is used, the gradation from white to black can be identified as 256 gradation levels, and with a 10-bit A / D converter, it can be identified as 1024 gradation levels. Therefore, 8 bit A /
An image reading apparatus using a D converter can identify 24 bits = approximately 16.7 million colors in color reading using a light source of three colors of RGB, and 30 bits = approximately 1.074 billion colors in the case of 10 bits.

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.
Image data obtained by binarizing an image signal obtained by, for example, turning on only G among the GB light sources at a certain threshold value by an image processing circuit incorporated in the gate array 11 is used. When reading an image such as a photograph and outputting the image to a monochrome printer, the image data is binarized using a halftone process such as a dither method or an error diffusion method using an image signal from the G light source. Is used. When processing color images, multi-valued (24 bit
etc.) Image data is suitable.

The image signal that has passed through the image processing circuit is output to a device such as a personal computer 13 via an interface circuit 12.

(Hinge Configuration) Next, the configuration for opening and closing the document cover 6 with respect to the apparatus main body 1 will be described. FIG. 4 is an explanatory view of a hinge structure for opening and closing the apparatus main body 1 and the document cover 6, and FIG. 5 is an explanatory view of a state in which the document cover is opened and closed.

As shown in FIG. 4, on the platen glass,
A document cover 6 and a hinge member 7 for pressing a document onto glass are provided in a concave portion 1 provided at a rear end of the apparatus main body 1.
a and a fitting portion between the projection 7a at the rear end of the hinge member and a projection 6b at the front end of the hinge member and a concave portion 6a at the rear end of the document cover. As a result, the document cover 6 is attached to the apparatus body 1 so as to be openable and closable.

As shown in FIG. 5, the rear end 6b of the document cover 6 projects rearward from the pivotal supports 6a and 7b with the hinge member 7, and the document cover 6 is restricted by the projecting portion so that the document cover 6 is hinged. The member 7 can be rotated only in one direction.

Further, a torsion compression coil spring 14 serving as an urging means is attached around the shaft supporting portions 6a and 7b, and the ends thereof are locked by a projection 7c formed on the document cover 6 and the hinge member 7. ing. As a result, the document cover 6 is constantly urged to open with respect to the hinge member 7. Further, the torsion compression coil spring 14 biases the document cover 6 in the direction of arrow a in FIG. 4 so that the positional relationship in the axial direction of the rotation axis of the document cover 6 and the hinge member 7 becomes constant. I have. As a result, the document cover 6 is urged so as to widen a surface A perpendicular to the rotation axis of the document cover 6 and a surface B perpendicular to the rotation axis of the hinge member 7.
The play in the direction of the rotation axis between the hinge member 7 and the hinge member 7 is moved.

Further, at the tip of the rotation of the document cover 6,
A suction cup 15 is attached. The upper surface of the apparatus main body 1 facing the suction cup 15 is finished to have a smooth surface so that the suction cup 15 can easily adhere. The sponge of the original cover 8 has a thickness such that the original cover 6 is closed and the suction cup 15 is slightly crushed in a state in which the sucker 15 is in close contact with the apparatus main body 1.

In the above arrangement, when the image reading apparatus is opened in a normal flat state and the original cover 6 is opened, the original cover 6 is fixed to the hinge member 7 by the effect of the overhanging portion at the rear end. Rotate integrally. Then, FIG. 5 (b)
As shown in the figure, when the opening angle exceeds 90 °, the opening posture is maintained.

Next, when a thick original such as a book is set and the original cover 6 is closed, as shown in FIG. 5 (c), the original cover 6 is centered on pivots 6a and 7b between the hinge member 7. As a result, the original pressing sheet 8 is bent downward by its own weight, so that the original pressing sheet 8 presses the original D. On the other hand, when a thin document is set and the document cover 6 is closed, the document cover 6 and the hinge member 7 are urged in the axial direction of the rotation shaft by the torsion compression coil spring 14, so that both rotate integrally. I do. Therefore, even in the case of a thin original, the original pressing sheet 8 is in close contact with the original, and the original is accurately fixed to the original platen glass.

In the case of vertical scanning, an original is placed on an original platen glass, the original cover 6 is closed, and the suction cup 15 is pressed from above, so that the original comes into close contact with the apparatus main body. At this time, since the sponge of the original pressure-bonding sheet 8 bends, the reaction force is applied to the original via the sheet material, and even if the original has wrinkles or curls, the original is brought into close contact with the original platen glass. At this time, the document cover 6 is easily rotated in the closing direction with respect to the hinge member 7 in order to place the apparatus vertically, but the open posture is maintained by the action of the torsion compression coil spring 14.
Therefore, a clear image can be read.

Further, since there is no backlash between the document cover 6 and the hinge member 7, the relationship between the document glass and the document cover becomes inconsistent when the document cover is closed as in the conventional case, and the document may easily move. Generation can be prevented.

[0033]

The present invention is constructed as described above.
With a simple configuration, it is possible to accurately fix thin and thick originals and perform clear image reading. The play between the cover member and the hinge member can be eliminated by the urging means.

[Brief description of the drawings]

FIG. 1 is a schematic view of a configuration of a color image forming apparatus according to an embodiment, wherein FIG. 1 (a) is a partially cut plan view, FIG. 1 (b) is a partially cut front view, and FIG.

FIG. 2 is an explanatory diagram of a configuration of a contact sensor.

FIG. 3 is a block diagram of a read image data processing by the image reading apparatus.

FIG. 4 is an explanatory diagram of a hinge configuration for connecting the apparatus main body 1 and a document cover 6 so as to be openable and closable.

FIG. 5 is an explanatory diagram illustrating a state in which a document cover is opened and closed.

FIG. 6 is a schematic diagram illustrating a configuration of a conventional flat bed image reading apparatus.

FIG. 7 is an explanatory view illustrating a state in which a conventional image reading apparatus is placed vertically.

[Explanation of symbols]

 D: Document 1: Device main body 1a: Concave part 2: Document table glass 3: Contact image sensor 4: Guide shaft 5: Slider 6: Document cover 6a: Concave part 6b: Rear end 7: Hinge member 7a: Convex part 7b: Convex part 7c: Projection 8: Original pressure bonding sheet 9: Amplifier 10: A / D converter 11: Gate array 12: Interface circuit 13: Personal computer 14: Torsion compression coil spring 15: Sucker

Claims (3)

[Claims] 1. An image reading apparatus which has a document cover which can be opened and closed with respect to an apparatus main body and which reads a document by a reading means, further comprising a hinge member for rotatably connecting the apparatus main body and a cover member. An end of the hinge member and the apparatus main body are rotatably supported, and the other end of the hinge member and a cover member are rotatably supported on the hinge member. An image reading apparatus, which urges a cover member in an opening direction and urges the cover member in a rotation axis direction. 2. The image reading apparatus according to claim 1, wherein a rotation range of the cover member is restricted with respect to the hinge member. 3. The image reading apparatus according to claim 1, wherein said urging means is a torsion compression coil spring.