JP3609198B2 - Image reading device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image reading apparatus using photoelectric conversion means comprising a CCD or the like. Application fields include image scanners such as image scanners and facsimiles.
[0002]
[Prior art]
As a conventional technique related to the present invention, as described in Japanese Patent Laid-Open No. 4-171436, in an image reading apparatus capable of optically reading a document image by an optical line sensor, a reflection member is provided around the light source. A document illuminating apparatus is known in which a slit is provided in the reflecting member.
[0003]
[Problems to be solved by the invention]
An image reading device irradiates a document with light from a light source, forms an image of the reflected light or transmitted light on a light receiving surface of a photoelectric conversion element such as a CCD, and converts it to an analog signal. The image information is read after being converted to. The analog signal converted from light by the photoelectric conversion element contains various noise components mixed in from the circuit pattern on the substrate, and then converted into a digital signal to be imaged. Therefore, the S / N is reduced, that is, the image is deteriorated. Cause.
[0004]
Generally, when a high-quality image is required with multi-value output such as DTP (desktop publishing), the dynamic range when converting an analog signal to a digital signal is increased, that is, light obtained on a photoelectric conversion element. By making the output as large as possible, it is possible to obtain a high-quality image with multi-level output.
[0005]
On the other hand, if the necessary information can be recognized with two outputs, such as filing applications, the output of the light obtained on the photoelectric conversion element can be a sufficient image even if it is not so large as compared with the applications such as DTP. Can be obtained.
[0006]
However, when both usage methods, such as DTP and filing, are required, the exposure amount by the light source is set in accordance with the maximum required amount. large. In addition, when the designated color is dropped out, such as for the purpose of OCR, the emission color of the light source is determined, and it is necessary to prepare a dedicated reading device.
[0007]
Accordingly, the present invention provides an image reading apparatus capable of obtaining appropriate image information by allowing the user to easily adjust the exposure amount and emission color required for reading according to the application by combining a light source and a reflecting mirror. The purpose is to provide.
[0008]
[Means for Solving the Problems]
To achieve the above object, a first aspect of the present invention, power supply harnesses controlling lighting of the light source to allow the lighting of up to two holding brackets of the light source is Rutotomoni up to two configurations at right and left A reflecting mirror that can hold a light source, one of the holding brackets includes a pressing member that compresses the mounted light source, and includes a reflecting surface having left and right end portions of the same shape as the light source at a position facing the light source. Can be attached by a holding bracket, and is provided with an openable / closable window that can be opened and closed above the light guide provided with the light source.
[0009]
According to a second aspect of the present invention, the opening / closing window is rotatable about a shaft serving as a fulcrum, and an interlock switch capable of shutting off the power supply to the light source is provided in the vicinity of the fulcrum. In the vicinity, there is provided a lever for turning on / off the interlock switch by a rotational motion .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of an image reading apparatus according to the present invention will be described with reference to the drawings. FIG. 1 shows a configuration in which light sources can be combined in the present invention. Reference numerals 8a and 8b denote light sources, and reference numeral 3 denotes an original glass.
[0012]
In FIG. 1A, the light emitted from the light source 8a strikes the original on the original 3 and becomes reflected light and travels downward in FIG. 1A. Thereafter, the first mirror 9 shown in FIG. The image is formed on the surface of the CCD 6 as a photoelectric conversion element through the second mirror 10, the third mirror 11, and the lens 5.
[0013]
In FIG. 1B, the original on the original glass 3 is directly irradiated from the light source 8a, is reflected by the reflecting mirror 7 facing the light source 8a, and strikes the original on the original glass 3 to increase the illumination light. The irradiated light becomes reflected light and travels downward in FIG. 1 (b), and then onto the CCD 6 surface via the first mirror 9, second mirror 10, third mirror 11, and lens 5 shown in FIG. Imaged. In this case, the exposure amount is increased by 30 to 40% compared to the exposure amount shown in FIG.
[0014]
In FIG. 1C, a light source 8b is provided at a position opposite to the light source 8a. The light that is irradiated on the document surface by the two light sources 8a and 8b and hits the document on the document glass 3 and becomes reflected light. The image is directed downward in FIG. 1C, and then imaged on the surface of the CCD 6 through the first mirror 9, the second mirror 10, the third mirror 11 and the lens 5 shown in FIG. In this case, the exposure amount is increased by 90 to 100% compared to the exposure amount shown in FIG.
[0015]
FIG. 2A is a perspective view showing the appearance of the entire image reading apparatus of the present invention. The automatic paper feeder 2 is rotatably mounted as shown in FIG. 2B around a support shaft (not shown) provided at the rear of the apparatus body 1. An original is placed on the original placement surface 20, read by automatically feeding the original onto the original glass 3 by the automatic paper feeder 2, and directly original without using the automatic paper feeder 2. Two types of reading are possible: reading placed on the top.
[0016]
FIG. 3 shows the internal configuration of the apparatus main body 1. In the apparatus main body 1, although not shown, a guide rail is provided in parallel with the document glass 3 in the document transport direction (left and right direction in FIG. 3), and two carriages (not shown) are provided by the guide rail. ) Is supported movably.
[0017]
A light source 8 and a first mirror 9 directed to a document reading position on the document glass 3 are mounted on the first carriage, and a second mirror 10 and a third mirror 11 are mounted on the second carriage.
[0018]
A lens 5 for focusing the reflected light to form an image and a photoelectric conversion element 6 for reading the image are attached on the optical path of the reflected light from the reflecting surface of the third mirror 11.
[0019]
The automatic paper feeder 2 has a paper feed roller 21 provided above the original placement surface 20, and the original reading position on the original glass 4 of the apparatus main body 1 from the upper surface of the original placement surface 20. A conveyance path that reaches the document pressing plate 29 is then provided. A pair of upper and lower separation rollers 23 and a feed roller 22 are provided in the conveying path, and a conveying drum 24 is provided in front of the conveying direction. Further, a conveyance roller 25 is provided in front of the original reading position on the original glass 4 in the conveyance direction, and a pair of paper discharge rollers 26 and 27 are provided in front of the conveyance direction.
[0020]
As shown in FIG. 3, a pressing plate 28 is provided on the upper surface of the original glass 4 in the vicinity of the original reading position on the original glass 4 of the apparatus main body 1, and the presence or absence of the original in the conveyance path is located in front of the conveyance roller 25. A sensor (not shown) for detecting the above is provided.
[0021]
When the automatic paper feeder 2 is used, when a document is placed on the document placement surface 20 and the copy start button is pressed, a command is sent from the host computer 30 to the CPU 32 via the interface 31 as shown in FIG. The CPU 32 sends a signal to the motor drive circuit 34 based on the data in the ROM 33 to drive the motor 35 and sends a signal to the light source lighting device 36 to light the light source 8. A feed roller 21, a separation roller 23, and a feed roller 22 driven by a motor 35 feed documents one by one to the conveyance path, pass through the document reading position on the document glass 4, and convey rollers 25, discharge rollers 26, 27, the document after reading is discharged onto the document pressing plate 29. During this time, the image on the document conveyed by the image reading unit 37 via the image processing unit 38 is read at the document reading position.
[0022]
That is, at the document reading position on the document glass 4, the light from the light source 8 is irradiated onto the document transported on the document glass 4, and the reflected light is sequentially transmitted by the first mirror 9, the second mirror 10, and the third mirror 11. The image of the original is read by irradiating and forming an image on the photoelectric conversion element 6 with the lens 5. The document after reading is sent from the image processing unit 38 to the CPU 32, and the conveying roller 25 and the discharge rollers 26 and 27 are driven by the instruction from the CPU 32 to be discharged onto the document pressing plate 29.
[0023]
Further, when the automatic paper feeder 2 is not used, the automatic paper feeder 2 is rotated upward about the support shaft 30 to place the document on the document glass 3 and the leading end of the transport roller 25. The document is set so as to enter the lower side, and the image of the original is read by the image reading unit 37 (see FIG. 4) while moving the carriage.
[0024]
That is, an image is read by moving a carriage mounted with the light source 8 and the first mirror 9 and a carriage mounted with the second mirror 10 and the third mirror 11 in a direction parallel to the document surface.
[0025]
FIG. 5 shows an embodiment of a pair of holding brackets 55 and 56 that hold both ends of the light source 8 on the first carriage. The holding brackets 55 and 56 are configured as a pair of left and right, and in one holding bracket 55, a pressing member 42 that presses the mounted light source 8 in the length direction and applies compression is provided. The pressing member 42 presses and holds the light source 8 against the holding bracket 56 by its own elastic force. The power supply harness 47 that controls the lighting of the light source 8 enables lighting control of a maximum of two light sources and is connected to each of the light sources 8, and lights one or two lamps by the lighting control.
[0026]
FIG. 6 shows an embodiment of the reflecting mirror 7. The shape of the left and right end portions of the reflecting mirror 7 is the same as that of the light source 8 and can be attached to the holding brackets 55 and 56. Therefore, when only one light source is used, the reflecting mirror 7 can be mounted at a position facing this one light source. The light irradiated from the light source 8 is reflected on the document by the reflecting surface 48 of the reflecting mirror 7 and the exposure amount can be increased.
[0027]
FIG. 7A shows a state where the open / close window 43 above the first carriage is opened. Thus, the opening / closing window 43 is removable. FIG. 7B shows a state in which the light source 8 on the first carriage is removed with the open / close window 43 opened.
[0028]
FIG. 8 shows the embodiment of the opening / closing window 43 more specifically. FIG. 8A shows a state in which the opening / closing window 43 is closed, and the interlock switch 45 is turned on by a lever 44 attached to the lower part of the opening / closing window 43. FIG. 8B shows a state in which the opening / closing window 43 is moved upward about the fulcrum 46, and the interlock switch 45 is turned off by the lever 44 attached to the lower part of the opening / closing window 43. While the interlock switch 45 is OFF, the power supply to the light source is interrupted to ensure safety.
[0029]
【The invention's effect】
According to the first aspect of the invention, the holding bracket of the light source is capable of holding up to two light sources, the holding bracket of the light source is constituted by pair, one of the holding brackets in the light source mounted A reflecting member having a pressing member for applying a compression, and having a reflecting surface having left and right end portions of the same shape as the light source at a position facing the light source can be attached by a holding bracket, and includes the light source. An open / close window that can be opened and closed above the light-guided body allows energy to be saved by irradiating two light sources when high image quality is required by adjusting the exposure amount or emission amount according to the application. When operating with, one light source can be irradiated and the user can easily select the image quality. In addition, even with a single light source, the exposure amount can be easily increased without increasing the amount of energy by disposing the reflecting mirrors at opposite positions.
[0030]
According to a second aspect of the present invention, the opening / closing window is rotatable about an axis serving as a fulcrum, and an interlock switch capable of interrupting power supply to the light source is provided in the vicinity of the fulcrum. In the vicinity of the fulcrum, there is a lever that turns the interlock switch on and off by rotational movement, so that when the user opens or closes the window, the power to the light source is turned off. It is possible to replace the light source .
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration in which light sources can be combined in an image reading apparatus according to the present invention.
FIG. 2 is a perspective view showing an example of the appearance of the image reading apparatus according to the present invention.
FIG. 3 is a diagram showing an example of an internal configuration of an image reading apparatus according to the present invention.
FIG. 4 is a block diagram showing an example of a signal processing system in the image reading apparatus according to the present invention.
FIG. 5 is an exploded perspective view showing an example of a light source mounting pressing member and a bracket applicable to the present invention.
FIG. 6 is a perspective view showing an example of a reflecting mirror applicable to the present invention.
FIG. 7 is a perspective view showing an example of an opening / closing window of a light source unit applicable to the present invention and showing a state in which the opening / closing window is opened.
FIG. 8 is a side view showing an example of the positional relationship between the opening / closing window of the light source unit and the interlock switch applicable to the present invention.
[Explanation of symbols]
55 Bracket 56 Bracket 7 Reflector 8a Light source 8b Light source 30 Support shaft 42 Press member 43 Open / close window 44 Lever 45 Interlock switch 46 Support point 47 Power supply harness 48 Reflecting surface

Claims (2)

In an image reading apparatus provided with photoelectric conversion means for receiving reflected light from an original of light irradiated by a light source and converting it into an electrical signal,
The power supply harness that controls the lighting of the light source can light up to two,
Retention bracket source is capable of holding the light source Rutotomoni maximum two consists of right and left,
One of the holding brackets includes a pressing member that gives compression to the mounted light source ,
A reflecting mirror having a reflecting surface having left and right end portions of the same shape as the light source can be attached by a holding bracket at a position facing the light source.
An image reading apparatus having a light source holding mechanism, wherein an openable / closable window is provided above a light-traversing body having the light source. 2. The image reading apparatus according to claim 1, wherein the opening / closing window is rotatable about an axis serving as a fulcrum, and an interlock switch capable of shutting off power supply to the light source is provided in the vicinity of the fulcrum. An image reading apparatus comprising a lever for turning the interlock switch on and off by a rotary motion in the vicinity of the fulcrum .

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