JPH08214117A - Image reader - Google Patents

Abstract

PURPOSE: To attain selectively reading in the dropout mode and the usual reading by arranging two light sources whose emitted light color differs at positions opposite to each other. CONSTITUTION: The reader has a 2nd light source 9-2 whose emitted light color differs from that of a 1st light source 9-1, and a light reflected in an original obtained by a light emitted from the 1st light source 9-1 onto an original on an original glass 13 is formed onto a CCD 5 via a 1st mirror 1, a 2nd mirror 2, a 3rd mirror 3 and a lens 4. The light emitted from the 1st light source 9-1 is reflected on reflecting mirrors (position shown in solid lines) arranged opposite to each other and reaches an original face. In this case, the 2nd light source 9-2 whose emitted light color differs is extinguished. When a read mode command with a dropout is received, a control section operates a drive mean of a reflecting mirror 8 to move the reflecting mirror 8 to a position (position shown in dotted lines) opposite to the 2nd light source 9-2. Thus, whether or not reading in the dropout mode is conducted is realized by key operation of one-operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an image reading section used in an image scanner or an image forming apparatus, and it is possible to arbitrarily switch between reading with dropout and reading without dropout. The present invention relates to an image reading device.

[0002]

2. Description of the Related Art In an image reading section of an image forming apparatus utilizing an electrophotographic process such as a copying machine, a printer or a facsimile machine, or an image scanner, a document surface set on a document table such as a contact glass. An image reading device for reading the image is used. In general, an image reading device converts the reflected light or transmitted light obtained by irradiating the original surface with light from a light source, converts it into an analog signal by a photoelectric conversion element such as CCD, and further by an A / D converter. Image information is read after being converted into digital signals. The digital image information obtained in this way causes a difference in the obtained image information if the light emission color of the light source illuminating the document is different. For example, when reading an original consisting of a frame part drawn in a predetermined color and a character part drawn in another color as in the case of OCR, it is desired to obtain only character information as read data. In this case (when you want to drop out the frame line information), place a filter of the same color as the frame line before the reflected light of the document is incident on the light receiving surface of the CCD, or change the light source to the specified emission color. By doing so, the requested color dropout is realized.

However, once the filter and the light source are set for reading in the dropout mode, the use of the reading device is limited to only the dropout mode. Therefore, in order to perform reading without dropout, the light source or the filter must be removed or replaced. This is because if the image forming apparatus side remains in the dropout mode and reading is performed without dropout, a situation may occur in which necessary information is not included in the image. This is because the image reading device set in the dropout mode reads the image with energy in a specific wavelength range cut off in the visible light range, so the human eyes feel directly when looking at this image. This is because the gray scale that is present is different from the gray scale received by the CCD.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and a one-touch key operation (or a command from a host machine) for selecting whether or not to perform reading in the dropout mode according to the contents of a read document. It is an object of the present invention to provide an image reading device that can be realized by.

[0005]

To achieve the above object, the invention according to claim 1 is an image reading apparatus equipped with photoelectric conversion means for receiving reflected light from a document illuminated by light from a light source and converting it into an electric signal. In 2 above, two light sources having different emission colors are arranged at positions facing each other. The invention according to claim 2 is provided with a movable plate that moves to shield the light emitting surface of the other light source when one of the two light sources is lit to illuminate the original. And The invention according to claim 3 is characterized in that reflective surfaces that reflect light are provided on both front and back surfaces of the movable plate.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is a diagram showing a main configuration of an image reading apparatus according to the present invention. Reference numeral 1 is a first mirror and 2 is a second mirror.
Mirror 3, 3rd mirror, 4 lens, 5 CCD (photoelectric conversion means), 6 first traveling body, 7 second traveling body, 8 reflecting mirror (shielding plate = movable plate), 9-1 Is the first light source, 9-
Reference numeral 2 is a second light source whose emission color is different from that of the first light source, and 13 is a document glass. Original reflected light obtained by being emitted from the first light source 9-1 and being irradiated on the original on the original glass 13 passes through the first mirror 1, the second mirror 2, the third mirror 3, the lens, and the CCD 5. Imaged above. The light emitted from the first light source 9-1 is reflected by a reflecting mirror (solid line position) arranged to face the original and reaches the original surface. This time,
The second light source 9-2 having a different emission color is in the off state. When there is a reading mode command accompanied by dropout, the control unit described later operates the driving means of the reflecting mirror 8 to move the reflecting mirror 8 to the position (dotted line position) facing the second light source 9-2. .

FIG. 2 is an external view of an example of an image reading apparatus having the image reading section as shown in FIG. 1, and FIG. 3 is a sectional view showing its internal structure. This image reading device
An apparatus main body 10 and an automatic document feeder 11 are rotatably supported on the apparatus main body 10 around a hinge portion provided at one end 11a. Reference numeral 12 is a paper discharge tray.
When documents are fed automatically, the automatic document feeder 11 is closed on the document glass as shown in the figure, and when the documents are set manually, the hinges are used as the center. This is performed by opening the paper device 11 and exposing the original glass.

As shown in FIG. 3, the apparatus main body 10 is provided with a document glass 13 on its upper surface, and first and second traveling bodies 6 and 7 that move right and left directly below the document glass are not shown. It is supported by a guide rail so that it can move back and forth. Other configurations of the reading optical system are the same as those in FIG. The automatic document feeder 11 has a paper feed roller 21 along the document placing surface 20, and passes from the upper surface of the document placing surface 20 to the reading position A on the document glass 13 of the apparatus main body 10 and the discharge tray 12. And a pair of upper and lower separating rollers 23a and 23b and conveying rollers 24 and 25 are provided in the conveying path 22, and the conveying roller 26 and the sheet discharging roller 27 are disposed on the sheet discharging side from the reading position A. To provide. Reading position A
1, a pressing plate 33 is provided on the upper surface of the original glass 13 as shown in FIG. 1, and a sensor 34 for detecting the presence / absence of an original in the conveying path 22 is provided in front of the conveying roller 25.

FIG. 4 is a block diagram showing a control system of the image reading apparatus of the present invention. The control section includes a CPU 37 for executing various processes according to a preset control program,
A ROM 38 storing a program, a RAM 45 storing processing results and data, an input / output circuit (interface) 36, and the like are provided. When a document is fed by using the automatic document feeder 11, the interface is set from the host computer while the document is placed on the document placement surface 20.
A command signal is sent to the CPU 37 via 6. The CPU 37 receiving this command sends a signal to the motor drive circuit 39 to drive the motor based on the data in the ROM 38, and also sends a signal to the light source lighting device 41 to turn on the light source 9. Then, the roller 2 driven by the motor 40
The originals are fed one by one to the conveyance path 2 by 1, 23a, 23b, etc., pass through the reading position A and the conveyance rollers 25, 26
At 27, the read document is discharged onto the discharge tray 12.

During this time, at the reading position A, the light source 9-1
The light from the source is irradiated on the original on the original glass 13, and the reflected light is received by the photoelectric conversion element 5 via the mirrors 1, 2, 3 and the lens 4. These optical systems correspond to the image reading unit 43 in FIG. The digitally converted image information from the image reading unit 43 undergoes required processing by the image processing unit 42 and is displayed as an image on a display unit such as a host computer. Further, in the reading device of the image forming apparatus, this image data is output to an image forming unit (not shown) to form an image on the recording paper.

The light sources 9-1 and 9-2 having different emission colors are
For example, one 9-1 is a normal fluorescent lamp and the other 9-2 is a light source having a constant emission color. Therefore, the image information of the light emitted from the second light source 9-2 and reflected from the document surface is the information obtained by removing the same color as the emission color as the dropout color. The reflecting mirror driving means 45 in FIG. 4 is means for moving the reflecting mirror 8 from the solid line position in FIG. 1 to the dotted line position so that the reading mode instructed by the host computer uses the first light source. Depending on whether it is the normal reading or the dropout mode using the second light source, the light source side is moved to a position where the original glass 13 can be illuminated. For example, in the case of normal reading, the first light source 9-1 is turned on, while the reflecting mirror 8 is moved to the position indicated by the solid line to amplify the emitted light and irradiate the original surface on the original glass. (Fig. 5 (b)). At this time, since the reflecting mirror 8 is configured to block the light traveling toward the light source (the light source 9-2 in this case) facing the light source, the light source 9-2 on the light-off side as shown in FIG. It is possible to prevent light from wrapping around inside.
Further, by forming both surfaces of the reflecting mirror 8 as reflecting surfaces, it can be used as a reflecting mirror for both light sources by simply moving between the solid line position and the dotted line position.

When reading with a drop color, the reflecting mirror 8 is moved to the position shown by the dotted line in FIG.
By illuminating only the light source 9-2, the emitted light is guided to the document surface. The reflecting mirror 8 is of course mounted on the first traveling body 6, and a mechanism for reciprocating the reflecting mirror 8 is as follows.
It is possible to use a solenoid or the like. In some cases, the reflecting mirror 8 may be manually moved between the solid line position and the dotted line position.

FIG. 6 is a flow chart showing the operation of the apparatus of the present invention. In step 1, whether or not the dropout mode is selected by a command from the host computer or the like, and in the normal reading mode, the first light source 9 is selected. -1 is turned on to capture the image data, and after the reading is finished, the first light source is turned off (steps 2 to 5). At this time, the reflecting mirror 8 is at the solid line position. Next, in step 2, the second light source 9
-2 is turned on, the reflecting mirror 8 is moved to the dotted line position, the light source 2 is turned on, image data is taken in, and the reflecting mirror 8 is returned to the solid line position after the second light source is turned off (step 2, 6-11). In the above embodiments, the present invention is applied to the image scanner, but the present invention can be applied to general reading devices of electrophotographic image forming apparatuses such as copying machines, facsimiles, printers and the like.

[0014]

As described above, according to the invention of claim 1,
In an image reading apparatus including a photoelectric conversion unit 5 that receives reflected light from a document illuminated by light from the light sources 9-1 and 9-2 and converts the reflected light into an electric signal, two light sources having different emission colors are mutually connected. Since they are arranged at opposite positions, it is possible to selectively perform normal reading and reading with dropout. According to the second aspect of the invention, when one of the two light sources is turned on to illuminate the document, the movable plate is provided to move so as to block the light emitting surface of the other light source. It is possible to prevent the reflected light from entering the other light source. In the invention according to claim 3, since the reflecting surfaces for reflecting light are provided on both front and back surfaces of the movable plate, the light from both light sources is reflected and guided to the original surface by simply reciprocating the movable plate. be able to.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a main part configuration of a reading device according to an embodiment of the present invention.

FIG. 2 is an external view of an image scanner using the device of the present invention.

FIG. 3 is an explanatory diagram of an internal configuration of the image scanner of FIG.

FIG. 4 is a block diagram illustrating a control system of the image reading apparatus of the present invention.

5A and 5B are comparison diagrams with and without a reflecting mirror.

FIG. 6 is a flowchart showing the operation of the present invention.

[Explanation of symbols]

1 1st mirror, 2nd mirror, 3rd mirror, 4
Lens, 5 CCD (photoelectric conversion means), 6 first traveling body, 7 second traveling body, 8 reflecting mirror (shielding plate = movable plate),
9-1 first light source, 9-2 second light source, 13 original glass,

Claims (3)

[Claims] 1. An image reading apparatus having photoelectric conversion means for receiving reflected light from a document illuminated by light from a light source and converting the light into an electric signal, in which two light sources having different emission colors are opposed to each other. An image reading device characterized in that the image reading device is arranged in. 2. A movable plate is provided to move when one of the two light sources is lit to illuminate a document, and the movable plate moves to block the light emitting surface of the other light source. Item 1. The image reading device according to item 1. 3. The image reading apparatus according to claim 1, wherein the movable plate is provided with reflective surfaces for reflecting light on both front and back surfaces thereof.