JPH0641421Y2 - Image reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an image reading apparatus having a color discrimination function.

[Prior Art] Conventionally, in an image reading apparatus having a color discrimination function of this type,
As shown in FIG. 6, light-emitting fibers TY ₁ , TY ₂ , ... TYn having, for example, yellow (Y) light-emitting elements LY ₁ , LY ₂ ,. Red (R) light emitting elements LR ₁ , LR ₂ , ...
R ₁ , TR ₂ , ... TRn are alternately arranged on the image reading surface of the reading head. On the other hand, for the yellow (Y) light emitting fiber, the light receiving fiber RY
₁ , RY ₂ ... RYn are provided, and the red (R)
Receiving fiber RR ₁ , R for light emitting fiber
R ₂ , ... RRn are arranged in parallel.

Then, first, the yellow (Y) light emitting elements LY ₁ , LY ₂ , L
Yn is caused to emit light, and the reflected light at the reading point Si (i = 1 to n) on the original surface is detected by the light receiving elements P ₁ , P ₂ , ... Pn, and then red (R) light is emitted. The elements LR ₁ , LR ₂ , LRn are made to emit light, and the same reading point Si is applied to the light receiving elements P ₁ , P ₂ , ... Pn
To detect.

Further, the electric signals output from the light receiving elements P ₁ , P ₂ , ... Pn are amplified by the respective amplifiers Ai (i = 1 to 2n) and each discrimination circuit Gi (i = 1 to 1n) of the next stage is amplified. (2n integer) is compared with a predetermined threshold value, and the color is discriminated by the control circuit.

[Problems to be solved by the invention] However, in this case, for reading one line,
Even when there is no color (white, that is, there is no image), the operation of yellow light and red light is always performed twice, which results in a problem that it takes time to read the image.

The present invention has been made in order to solve the above problems, and determines the presence or absence of an image at the reading point on the document surface based on the irradiation of the first light source, and there is no image (white).
It is an object of the present invention to provide an image reading device capable of speeding up reading of a two-color image by stopping the irradiation of the light from the second light source when the determination is made.

[Means for Solving the Problems] In order to achieve this object, the image reading device of the present invention is
Regarding the first and second light sources for irradiating the document surface with light, the irradiating means for sequentially irradiating the same spot on the document surface with the light from each of the light sources, and the light irradiating the document surface from each of the light sources. Detecting means for individually detecting the reflected light from the original surface of the original, and determining the presence or absence of an image on the original surface based on the amount of the reflected light of the light from the first light source detected by the detecting means. No. 1 discriminating unit and the first discriminating unit discriminates that there is an image on the document surface, the original document based on the amount of reflected light of the light from the second light source detected by the detecting unit. Second determining means for determining the color of the image on the surface;
When the first discriminating unit discriminates that there is no image when the light of the first light source is applied to the same spot, the irradiation of the light of the second light source is stopped and the original is
When the line is fed, the control of irradiating the light of the next first light source is performed, and when the first determining means determines that there is an image, the light of the second light source is emitted, and the original is 1
And a control means for controlling the line feeding.

[Operation] In the image reading apparatus of the present invention having the above configuration,
The control unit first irradiates the spot on the document surface with the light from the first light source by the irradiation unit, detects the reflected light from the document surface by the detection unit, and the amount of the reflected light is equal to or more than a predetermined amount. In the case of, the first discriminating unit discriminates it as white, that is, white data, and uses it as image data, and the original is fed for one line without irradiating light with the light of the second light source. The irradiation of the next reading spot with the light of the first light source is performed.

Further, when the amount of light reflected from the document surface by the light of the first light source is smaller than a predetermined amount, the first discriminating unit discriminates that there is an image, and then the irradiation unit forms the same spot. Irradiation with the light of the second light source is performed, the light reflected from the document surface is detected by the detection unit, and the color of the image on the document surface is determined by the second determination unit, which is used as image data. . Then, the original is fed by one line.

Embodiments FIG. 1 is a perspective view showing an example of this type of optical image reading apparatus. In the illustrated apparatus, an image reading head 3 is arranged to face a platen roller 2 supported between the frames 1a and 1b, and a head support plate 14 for supporting the image reading head 3 is provided.
Is pulled and urged to one frame 1b via a spring 15, while an eccentric cam disk 18 is axially attached to a rotary shaft 17 provided on one side of the frame 1b, and the circumference of the eccentric cam disk 18 is A cam follower 16 provided on the head support plate 14 is in sliding contact with the surface so as to resist the pulling force of the spring 15. The motor 4 as a drive source is connected to the rotary shaft 17 via gears 19 and 20. Further, a pulse code plate 21 having a large number of slit grooves formed radially is axially mounted on the rotary shaft 17, and an encoder including a light emitter and a light receiver.
22 is attached with the surface of the pulse code plate 21 sandwiched therebetween.

FIG. 2 shows an image reading head used in this optical image reading apparatus. This image reading head 3
As described above, the circular arc surface 11a of the head base 11 having a fan-shaped cross section has a yellow (Y) light emitting element LY ₁ , L at the base end as described above.
Y ₂ , ... LYn are connected to yellow (Y) light emitting fibers TY ₁ , TY ₂ , TYn, and red (R) light emitting elements LR ₁ , LR ₂ , ... at the base end.・ Red (R) light emitting fibers TR ₁ , TR ₂ , ... TRn in which LRn are spliced are arranged alternately in one line and at equal intervals, and correspond to each of the light emitting fibers. The base ends of the same number of yellow (Y) light receiving fibers RY ₁ , RY ₂ , ... RYn and red (R) light receiving fibers PR ₁ , PR ₂ ,. Multiple light-receiving elements PY ₁ , PY ₂ , ... PY
The head cover 12 covers it. Each of the light emitting elements LY ₁ , LY ₂ , ... LYn, LR ₁ , L
The R ₂ , ... LRn and the light receiving elements PY, PR are provided on the printed circuit board 13 and attached to the flat plate surface 11b of the head base 11.

Therefore, in the optical image reading apparatus configured as described above, when the motor 4 is driven, the platen roller 2
The amount of movement of the image reading head 3 which reciprocates in the axial direction is twice the eccentric amount a of the eccentric cam disk 18, that is, the amount of 2a. Therefore, when reading red and black images on a sheet of paper, yellow (Y) or red (R) is generated by the light emitting elements LY and LR at three points where the moving amount of the image reading head 3 is −a, ± 0, + a. Also, the wavelength light is emitted toward the Y surface of the document. The order in which the light of this wavelength is emitted is normally that when the image reading head 3 is at the point -a in FIG. 3, the light emitting fibers TY ₁ , TY ₂ , ... By moving in the A direction and emitting light of TY ₁ , TY ₂ , ... In the same manner at the points of ± 0 and + a, the reading by irradiation of yellow (Y) light for one line is performed. finish.

Next, when the moving direction of the image reading head 3 is reversed and the image reading head 3 is located at the point + a, the light emitting fibers TRn, TR ₂ and TR ₁ are sequentially emitted, and the image reading head 3 moves in the B direction to a point of ± 0. , -A, TRn, ..., TR ₂ , T
When R ₁ is sequentially emitted, the reading by irradiating one line of red (R) light is completed. Where LY
(-A) and LR (± 0), LY (± 0) and LR (-a), LY (+
In a) and LR (± a), the same point on the original Y surface is read.

That is, a certain point on the document Y surface is read by both LY and LR, and the read results of both are calculated by the data processing circuit as the discrimination means and control means of the present invention to become color-discriminated image data. .

Next, an image reading method in the optical image reading apparatus thus configured will be described with reference to FIGS. 4 and 5.

First, the reading process for one line by the light emitting element LY as described above is performed. That is, the light emitting element LY emits yellow (Y) wavelength light toward the document Y surface via the light emitting fiber TY, and the reflected light at the reading point on the document Y surface is received by the light receiving element PY via the light receiving fiber RY. Detected. Further, the output (read result) from each light receiving element PY is sent to the data processing circuit.

Then, in the data processing circuit, calculation is performed based on the amount of reflected light, and "0" or "1" is obtained as the output of LY. Further, all the outputs of LY are subjected to color discrimination based on the truth table shown in FIG. That is, the data processing circuit determines whether or not the output of LY is "1" in one line. If there is an output of LY of "1", the moving direction of the image reading head 3 is reversed and the same line is read by LR as described above.

If the output of LY in one line is "0", it can be judged as the line of "all white" data without reading again by LR.
The reading by is stopped and the platen roller 2 is driven to move the document Y by the next one line, and the reading by LY is continuously performed. In other words, when the image reading head 3 is moved in the A direction, LY is used for reading and LR is used for moving in the B direction, and LY is used for detecting whether or not there are two recorded light sources, and LR is used for color discrimination. It is intended to increase the speed of two-color reading by sharing the work and performing "all white" discrimination in the data processing circuit in the middle. Particularly, two-color originals, which are written in red in black characters, which are the most widely used everyday, can be read at a speed twice as fast as in a normal case between lines, so that the effect is remarkable.

According to the truth table shown in FIG. 4, when the output of LY is “0”, it is determined as “white” regardless of whether the output of LR is “0” or “1”. It is used to detect the presence or absence of recording on the surface, and LR is used to determine the color of recording.

Although the shuttle system has been described in the above embodiments, it goes without saying that the shuttle system can also be applied to the serial system and the line system.

[Advantages of the Invention] As is clear from the above description, according to the image reading apparatus of the present invention, the discriminating means of FIG. 1 causes the discriminating means of FIG. When it is determined that there is no image in the image, and when it is determined that there is no image, the irradiation for the color determination of the image by the light of the second light source is not performed, so that the reading of the two-color image can be speeded up. it can.

[Brief description of drawings]

1 to 6 show an embodiment embodying the present invention. FIG. 1 is an external perspective view of an image input device according to an embodiment of the present invention, and FIG. An exploded perspective view of the read head used, FIG. 3 is an explanatory view of an operating state,
FIG. 4 is a truth table of color discrimination in the data processing circuit, FIG. 5 is a control flow chart of the present invention, and FIG. 6 is an electric control block diagram of an image reading head having a color discrimination function. 2 ... Platen, 3 ... Image reading head, 3 ... Motor, 11 ... Head substrate, TYi ... Yellow (Y) light emitting fiber, TRi ... Red (R) light emitting fiber, R
Yi ... Yellow (Y) light receiving fiber, RRi ... Red (R) light receiving fiber, LY ... Yellow (Y) light emitting element, LR ... Red (R) light emitting element, P ... Receiving light Element, Y ... manuscript.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Takayuki Matsumoto 9-35 Hotta-dori, Mizuho-ku, Aichi Prefecture Nagoya City Brother Industry Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. A first and a second light source for irradiating a document surface with light, an irradiation unit for sequentially irradiating the same spot on the document surface with light from each of the light sources, and each of the light sources for irradiating the document surface. Detecting means for individually detecting the reflected light from the original surface with respect to the irradiated light, and the image on the original surface based on the amount of the reflected light of the light from the first light source detected by the detecting means. First discriminating means for discriminating the presence / absence, and the amount of reflected light of the light from the second light source detected by the detecting means when the first discriminating means determines that there is an image on the document surface. And a second discriminating means for discriminating the color of the image on the document surface based on the above, and the first discriminating means discriminating that there is no image when the light of the first light source is applied to the same spot. Occasionally, irradiation with the light from the second light source is stopped and the original is
When the original is fed by one line, the light of the first light source is emitted, and when the first determining means determines that an image is present, the light of the second light source is emitted, so that the original is equivalent to one line. An image reading apparatus, comprising: a control unit that controls feeding. 2. The first light source is a yellow light source, and the second light source is a red light source that determines whether the color of the image on the document surface is red or black. The image reading apparatus according to claim 1, wherein: