JPH11355486A - Image reader and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily attach a platen glass to a cover of an image reader by a glass attaching member and to prevent a document from being caught between the platen glass and the glass attaching member. SOLUTION: In this image reader, a platen glass 1 is attached to a cover 11, which is provided with four peripheral walls, by longitudinal movement, and a document is placed on the platen glass and is read. The platen glass is covered with ceiling members 11a and 11b provided in front and rear walls of the cover when viewed in the moving direction of the platen glass, and at least one of right left sides of the platen glass is fixed to right and left walls by a glass attaching member 12 which is fixed to this one side by an adhesive or the like as shown by 12a with a part of the front part in this moving direction left unfixed, thereby the platen glass is attached to the cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of reading an original such as a photograph or a document, converting the original into digital data, and outputting the digital data.
The present invention relates to a device configuration of an image reading device for computer input.

[0002]

2. Description of the Related Art FIG. 5 is a schematic diagram showing the configuration of a color image reading apparatus.

[0003] P is a read original placed on the original platen glass 100, and an image on the original is read by scanning the reading unit 101 in parallel with the original platen glass 100. As shown schematically in FIG. 6, the reading unit 101 has three color LEDs 101R, which are light sources for irradiating a document, inside thereof.
101G, 101B, rod lens array 101 for imaging reflected light from a document on a light receiving element of an image sensor
L and an image sensor 101S are incorporated.
The light sources of the three colors 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.

A reading unit 101 includes a slider 102 which slides on a guide shaft 103 fixed to the apparatus main body.
Fixedly supported on top. A belt 1 for transmitting power from a motor 105 serving as a scanning drive source is provided on the slider 102.
04 is fixed. By the forward and reverse rotation of the motor, the reading unit can perform reciprocal scanning in the range of the platen glass.

[0005] In addition to the above, the components of the image reading apparatus include an electrical unit 106 including a control board and a power supply. These components are arranged in a cover 111 that fixedly supports the platen glass. The inventor has previously proposed the following cover.

[0006] The cover 111 is provided with ceilings 111a and 111b along two sides of the front and rear sides (left and right directions in FIG. 1) of the hollow box.
And is made by molding.
The distance between the front and rear side walls of the cover 111 is set longer than the entire length of the platen glass 100, and a slide margin 111c for mounting the glass is provided on the front side wall. As shown in the drawing, the document table glass 100 is inserted with its front end inserted toward the near side of the cover 111 and then shifted rearward.

In the drawing, reference numeral 112 denotes a plate for holding down a glass, and each bent portion has a hook portion 112a at several places. The cover 111 has hook claws 111d at positions facing the hooks of the glass pressing plate. Place the platen glass 100 on the step 111e of the cover 111,
The cover of the apparatus is formed by fitting the left and right glass pressing plates from above so that the hooks engage with the claws of the frame.

A document cover 111 for pressing a document onto the glass is mounted on the document table glass so as to be openable and closable.

FIG. 7 is a block diagram of the read image data processing by the image reading apparatus. An image output signal read by the image sensor 101 in synchronization with the sequentially blinking LED is sent to an amplifier 121 and amplified, and then converted into a digital image signal by an A / D converter 122. A
The / D converter divides the dynamic range of the image sensor (the read output difference between the pure white part and the pure black part on the document) by the number of bits, and assigns the number of gradations according to the brightness of the image on the document. For example, if an A / D converter with a resolution of 8 bits is used, the interval from white to black is 256
, And in the case of a 10-bit A / D converter, 1024 gradation levels can be identified. Accordingly, in an image reading apparatus using an 8-bit A / D converter, 24 bi-colors are read in a color reading using a light source of three colors of RGB.
t = approximately 16.7 million colors, 30 bits for 10 bits =
About 1.074 billion colors can be identified.

There are several types of output modes of the image signal 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 lighting, for example, only G among the GB light sources by a certain threshold value in an image processing circuit incorporated in the gate array 123 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 (24b
it etc. ) Image data is suitable.

The image signal that has passed through the image processing circuit is sent to a device 20 such as a personal computer via an interface circuit 124.
0 or output to the image forming apparatus. In the case of an image forming apparatus, for example, by a laser beam modulated with an image signal,
An electrostatic latent image is formed on a photosensitive drum by an electrophotographic method.
The developing unit develops the latent image using toner as a developer to form a toner image, and the toner image is transferred to a sheet by the transfer unit. The transferred sheet is conveyed to a fixing unit, where the toner image is heated and fixed on the sheet.

[0012]

The above-described housing construction of the image reading apparatus has been previously proposed by the present inventor. In this case, the image reading apparatus is provided between a platen glass and a sheet metal plate. There is a possibility that a gap is easily formed, and the document may enter the gap and break. In addition, if the cover and the glass pressing plate are not sufficiently fitted, the platen glass may rattle.

The present invention solves the above problems,
It is an object of the present invention to provide an image reading apparatus in which a gap between a platen glass and a glass pressing plate is eliminated and the platen glass can be firmly fixed.

[0014]

Means for Solving the Problems In order to achieve the above object, a means of the present invention is to attach a platen glass to a cover having four peripheral walls by moving the platen back and forth, and place an original on the platen glass. In the image reading apparatus configured to be placed and read, the platen glass is covered by ceiling members provided on the front and rear walls of the cover when viewed in the moving direction of the platen glass, and at least one side of the platen glass is attached to the platen glass. The document table glass is attached to the cover by fixing to the left and right walls with glass attaching members fixed with an adhesive or the like while leaving a part of the front part in the moving direction on one side.

[0015]

[First Embodiment] The present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 are configuration examples of an image reading apparatus according to the present invention. In the figure, P is the platen glass 1
An image on the original is read by scanning the reading unit 2 in parallel with the original platen glass 1 on the original placed above. The reading unit 2 incorporates a light source for illuminating the original, a lens that forms reflected light from the original on a light receiving element of the image sensor, and an image sensor. Reference numeral 11 denotes a frame body also serving as an exterior cover, in which the platen glass 1,
In addition to the reading unit 2, a rail for guiding the reading unit to travel, a transmission mechanism for transmitting a driving force to the reading unit, a motor as a driving source, a control board, a power supply, and the like are housed.

The cover or frame 11 is formed in a hollow box shape having four front and rear and left and right peripheral walls and a bottom plate. It is made by molding. In the present invention, the front and rear refer to the front and rear in the moving direction when the platen glass is attached to the cover. In FIG. 1A, the right side is front, the left side is rear, the upper side is left, and the lower side is right. However,
The platen glass 1 can also be mounted by moving it up and down as seen in FIG. 1A, in which case the upper side is the front and the lower side is the rear. Cover 1 more than full length of platen glass 1
The distance between the front and rear side walls is set to be long, and a sliding margin 11d for mounting glass is provided on the front side wall between the ceiling 11a and the rib 11c.

In the drawing, reference numeral 12 denotes a resin glass holding plate or glass mounting member having a function as a reference when setting an original. Are fixed in parallel and at predetermined intervals. Reference numeral 12a (hatched portion) indicates an attached portion or a fixed portion, and a part of the front end portion of the plate 12, which is a mounting member, is not fixed. Also, at the front end of the plate, there are left and right positioning protrusions or claw portions 12b with respect to the cover and front and rear direction positioning protrusions or claw portions 12c, and also at the rear end side, with left and right positioning protrusions or claw portions 12d. Is provided. The cover 11 is provided with grooves 11f, 11g, and 11h, which are fitting concave portions corresponding to these convex portions.

Next, a method of mounting the original platen glass having the above configuration will be described with reference to FIG. First, the front end of the platen glass 1 is inserted into the near side of the cover 11. At this time, as shown in FIG. 3B, the front portions of the glass holding plates at both ends are lifted. As mentioned above, this part is not bonded to the glass, so that it can flex and lift off the glass when lifted. When the glass is shifted to the near side along the cover sliding margin 11c, the rear end of the glass eventually falls into the glass mounting portion of the cover. Then, when the glass is shifted to the rear, the front and back surfaces of the glass cover 1
1b and the rib 11e, the positioning claw 12d at the rear end of the plate fits into the corresponding groove of the cover. Subsequently, when the front end of the plate is pushed downward, the positioning claw 12b in the left-right direction and the positioning claw 12
c is fitted in the corresponding groove of the cover, and the original table glass is fixed to the cover.

According to the present invention, the plate is stuck to the platen glass so that the platen is not pinched as in the prior art, and the platen glass is securely fixed. Further, as a component for mounting the document table, the cost of parts is reduced because the mounting member is a single component, and the assembling workability is also improved.

[Embodiment 2] In order to guarantee the safety of the product to the user, it is required that the apparatus cannot be disassembled without any tools. Therefore, in the present embodiment, an apparatus provided with a decomposition preventing means will be described with reference to FIG.

The basic configuration is the same as in the first embodiment. A projection 22 d is provided at the tip of the positioning claw 22 c in the front-rear direction of the glass holding plate 22, and a cover 21 is provided.
A hole 21d for engagement is provided at a position facing the protrusion 22d.
Is provided. The hole is small enough to accommodate a thin screwdriver.

When the glass is assembled into the cover in the same procedure as in the above-described embodiment, and the front end of the plate is pushed downward, the front, rear, left and right positioning is performed, and the projections 22d of the plate engage with the holes 21d of the cover. . The hole is small enough and the upper projection is deep enough so that the cover cannot be opened without tools such as a clock screwdriver, ensuring safety.

The projections and holes for realizing the same function are not limited to this position, but may be provided at any position such as the tip of another positioning portion.

[0024]

As described above, according to the present invention,
The platen glass is covered by ceiling members provided on the front and rear walls of the cover when viewed in the direction of movement of the platen glass, and at least one of the left and right sides of the platen glass, and a part of the front part in the moving direction is left on the one side. By fixing the platen glass to the cover by fixing to the left and right walls with glass mounting members fixed with an adhesive or the like, there is no need to sandwich the original between the platen glass and the glass mounting member. ,
The cost of parts for mounting the platen glass can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of an image reading apparatus embodying the present invention.

FIG. 2 is a diagram showing a main part of a configuration example of an image reading apparatus embodying the present invention.

FIG. 3 is a diagram showing an example of assembling an image reading apparatus embodying the present invention.

FIG. 4 is a diagram showing a main part of an image reading apparatus according to another embodiment of the present invention.

FIG. 5 is a diagram illustrating a configuration example of a conventional image reading apparatus.

FIG. 6 is a diagram showing a conventional image reading unit.

FIG. 7 is an image data processing block diagram of a conventional image reading apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Original platen glass 2 ... Reading unit 11 ... Cover 11a, 11b ... Ceiling member 11c ... Rib 11d ... Moving amount 11f, 11g, 11h ... Concave part 12 ... Glass holding plate 12a ... Adhesive part 12b, 12c, 12d ... Convex part

Claims (7)

[Claims] 1. An image reading apparatus in which an original platen glass is attached to a cover having four peripheral walls by moving back and forth, and an original is placed on an original glass platen for reading. Covering the platen glass with ceiling members provided on the front and rear walls of the cover when viewed in the direction,
By fixing at least one of the left and right sides of the platen glass to the left and right walls with a glass attachment member fixed with an adhesive or the like while leaving a part of the front part in the moving direction on the one side,
An image reading apparatus wherein a platen glass is attached to a cover. 2. The glass mounting member according to claim 1, wherein at least a front portion of the glass mounting member is provided with a first convex portion for restricting left and right movement, and a second convex portion for regulating front and rear movement is provided on a side portion thereof. A first concave portion in which the first convex portion is fitted is provided in the ceiling member, and a second concave portion in which the second convex portion is fitted is provided on the left and right walls of the cover. Image reading device. 3. The image reading apparatus according to claim 1, wherein the distance between the front and rear walls is longer than the front and rear dimensions of the platen glass in order to allow for movement when mounting the platen glass. 4. The image reading apparatus according to claim 2, wherein a rib for supporting a platen glass is provided below the ceiling member. 5. The cover according to claim 2, wherein a locking portion is formed on the second convex portion, and holes for engaging the locking portion are formed on at least one of the left and right walls of the cover. Image reading device. 6. The image reading apparatus according to claim 5, wherein the engagement between the locking portion of the second protrusion and the hole is at least large enough to prevent the finger from being released by a finger. 7. An image forming apparatus comprising: the image reading apparatus according to claim 1; and an image forming unit that forms an image based on information read by the image reading apparatus.