JP2659116B2 - Image reading head with color discrimination function - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading head having a color discriminating function suitable for reading an image of a color original.

2. Description of the Related Art Conventionally, as shown in FIG. 5, a plurality of light emitting fibers Ti (i = 1 to an integer of 1 to n) and a corresponding number of light receiving fibers Ti are used as an image reading head of this type. fiber
Ri (i = 1 to n) and the light emitting fiber Ti
When light from each light-emitting element Li (i = 1 to an integer of n) is irradiated onto the original Y through the
(I = 1 to n) is reflected light from the light-receiving fiber.
Light is received by each light receiving element Pi (i = 1 to n) through Ri. The electric signal output from each light receiving element Pi according to the amount of received light is converted into each amplifier Ai (i = 1 to n).
And is compared with a predetermined threshold value in each of the next-stage discrimination circuits Gi (i = 1 to an integer of n).
For example, it is determined whether Si is white or black.

On the other hand, in the case of an image reading head having a color discriminating function of not only black and white but also two or three or more color images, the embodiment of FIG. 5 is slightly modified and FIG. It shows, for example, at the base end of each light emitting fiber Ti,
Light emitting diode (LED) L that emits light of yellow (Y) wavelength
Light emitting diode (LE) that emits Yi and red (R) wavelength light
D) LRi are arranged respectively. In this case, first, one light emitting element LYi (or LRi) emits light, and then the other light emitting element LRi (or LYi) emits light. Then, the light emitted from each of the light emitting elements LYi and LRi is applied to the surface of the color original Y via one common light emitting fiber Ti, and the reflected light is further received via the light receiving fiber Ri (not shown). Received by Pi. Then, each light receiving element Pi outputs an electric signal corresponding to the amount of received light of each of the yellow (Y) and red (R) wavelength lights, and the electric signal is compared with a predetermined threshold by each discrimination circuit Gi, If both the (Y) electric signal and the red (R) electric signal are at a lower level than a predetermined threshold value, black is obtained. Conversely, if both are at a high level, white is obtained. If so, the color is determined as red.

[Problems to be Solved by the Invention] However, according to such a conventional image reading head with a color discrimination function, the light incident area of the base end face of each light emitting fiber Ti is divided by half between the two light emitting elements LYi and LRi. Therefore, the amount of light incident on the light emitting fiber Ti is halved, which causes a problem that the light receiving sensitivity is reduced and the color discrimination accuracy is deteriorated. There is also a problem that the manufacturing cost is increased due to difficulty in positioning the light emitting elements LYi and LRi in manufacturing.

[Object of the invention] The present invention has been made in view of such problems,
An object of the present invention is to provide an image reading head having a high-performance color discriminating function at low cost.

[Means for Solving the Problems] To achieve this object, an image reading head with a color discrimination function according to the present invention comprises a head base having a plurality of light-emitting fibers and the same number of light-receiving fibers corresponding to the light-emitting fibers. Are arranged in pairs, and a plurality of types of light having different wavelengths are emitted from the end on the head reading surface side of each light emitting fiber, and light emitting fibers emitting light of the same wavelength are spaced at equal intervals and different from each other. The gist is that the light emitting fibers that emit light of the wavelengths are alternately arranged on the head reading surface at small intervals so as not to interfere with each other.

[Operation] With such a configuration, the image reading head of the present invention is relatively moved in the direction in which the light emitting fibers are arranged on the color document surface, so that light of different wavelengths is irradiated to the same reading point on the color document surface. For example, the color of the color document surface can be determined.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a shuttle type image reading head as an example of the present invention. The image reading head shown in FIG.
A large number of light emitting fibers T1, T2,..., Tn on the circular arc surface 1a of the head base 1 having a sector shape in cross section, and the same number of light receiving fibers R1, R2,. Are respectively stretched, and the top is covered by the head cover 2. A printed circuit board 3 is adhered to one flat surface 1b of the head base 1, and a suitable number of light emitting elements LY, LR and light receiving elements PY, PR each composed of a phototransistor are mounted on the printed circuit board 3. I have. More specifically, in the present invention, the light emitting fibers T1, T2,...
The Tn groups are grouped into medium unit quantities of ten each, and the light emitting fiber groups of each medium unit amount are further grouped into small unit quantities of five. And this is the light emitting fiber T1, T
Taking the case of 2 ... T10 as an example, one small unit of light-emitting fibers T1, T2,..., Which emits yellow (Y) wavelength light at the base end of each fiber of the T5 group Element LY1, LY
... LY5 are arranged, respectively, and light emitting elements LR1 and LR2 emitting red (R) wavelength light are provided at the base ends of the other small unit light emitting fibers T6 and T7. ...
・ ・ LR5 is arranged respectively. Also, the light emitting fibers T1, T2,..., And T5 that emit yellow (Y) wavelength light are equally spaced, and the light emitting fibers T6, T7, and that emit red (R) wavelength light. The light-emitting fibers T1, T2, and T10 are arranged at equal intervals between T10, and the yellow (Y) light and the red (R) light emitted from the reading both ends of the head main body 1 are emitted in a state where they do not interfere with each other. ...
・ T10 is arranged at small intervals. In this embodiment, all the light emitting fibers T1, T2,..., T10 are arranged at equal intervals for the sake of explanation. On the other hand, the base ends of the light-receiving fibers R1, R2,..., R5 arranged corresponding to the light-emitting fibers T1, T2,. The light receiving elements P6 are connected to the light receiving elements PY, and the base ends of the light receiving fibers R6, R7,..., R10 group arranged corresponding to the other light emitting fibers T6, T7,. They are combined into one and connected to one light receiving element PR. In this case, the former light receiving element PY is a photodiode excellent in sensitivity to yellow (Y) light, and the latter light receiving element PR is a photodiode excellent in sensitivity to red (R) light.

FIG. 2 shows an optical reading apparatus to which the image reading head 10 is applied. In this figure, while a platen roller 12 is supported between the frames 11a and 11b, a head support plate 13 is located on the front side of the platen roller 12 between the frames 11a and 11b in the axial direction of the platen roller 12. The image reading head 10 is fixedly mounted on the head support plate 13 in such a manner as to be in close proximity to the surface of the platen roller 12. The head support plate 13 is pulled and urged to one frame 11a via a spring 14, and a cam follower 15 protruding from the head support plate 13 is provided.
Is in sliding contact with a peripheral surface of an eccentric cam disk 17 formed on a rotating shaft 16 rotatably supported on one side of the frame 11a so as to resist the traction force of the spring 14. In this case, the eccentric distance between the center of the eccentric cam disk 17 and the center of the rotating shaft 16 is made to correspond to the tip pitch interval a of the light emitting fibers T1, T2,..., T10. Further, the rotating shaft 16 is connected to a motor 18 as a driving source thereof. That is, a driven gear 20 that is axially mounted on the rotating shaft 16 meshes with a drive gear 19 of a motor 18 provided on one side of the frame 11a. The rotary shaft 16 is also provided with an encoder 21 having a pulse code surface in which a number of slit grooves are radially opened. Although not shown, the encoder 21 is provided with a light emitter and a light receiver opposed to each other with a pulse code surface interposed therebetween, and a pulse when light from the light emitter is transmitted or cut off at regular intervals with the rotation of the pulse code surface. The frequency is detected by the light receiver. LY5, LR1, LR2,... LY5, LR1, LR2,.
··· It is configured that the light emission timing of LR5 is controlled.

In the optical reading apparatus thus configured, when the motor 18 is driven, the moving amount of the image reading head 10 reciprocating in the axial direction of the platen roller 12 is twice the eccentric amount of the eccentric cam disk 17. That is, the amount is 2a. So now,
At the three points where the moving amount of the read head 10 is -a, ± 0, + a, predetermined light is emitted from the light emitting fibers T1, T2,. The order in which light is emitted from each of the light emitting fibers T1, T2,..., Tn is as follows. First, the light emitting fibers T1, T2,. Is emitted,
Next, T2 and T7 follow, and finally light is emitted from the light emitting fibers T5 and T10. Then, for example, this read head
Assuming that yellow (Y) light is applied to a point on the original Y surface when the movement amount of the read head 10 is −a, the read head 10
Is moved and the movement amount becomes ± 0, red (R) light is irradiated this time at the previous point. Therefore, yellow (Y) light and red (R) light are sequentially irradiated at each reading point on the document Y surface, and as a result, yellow (Y) light and red (R) light are respectively applied to the light receiving elements PY and PR. Received. Therefore, as in the related art, the color is discriminated by being converted into an electric signal and compared with a predetermined threshold value. When reading of one line is completed, the original Y is moved by the next one line by driving the platen roller 12, and
The operation of the read head 10 is repeated.

Thus, in the present invention, by moving the image reading head 10 in the direction in which the light emitting fibers T1, T2,. Is determined. Therefore, accurate color discrimination can be carried out as long as the light emitting fibers T1, T2,... In the above embodiment, the case where the color discrimination is performed at three points where the moving amount of the image reading head is -a, ± 0, -a is described. + A / 2,
The number of discrimination points can be increased as in + a, so that color discrimination can be performed in a finer partitioned area. In the above embodiment, the light emitting phi T1, T2,...
The light emitting element LY or LR is arranged for each, and the light receiving fiber R
1, R2, ..., Rn are connected together to one light receiving element PY or PR, but the reverse is applied to the light-emitting fibers T1, T2, ..., Tn. Connected to one light emitting element LY or LR, receiving fibers R1, R2 ... R
n may be such that the light receiving elements PY or PR are arranged one by one. In this case, each light emitting fiber T1, T2 ... Tn
, And light can be emitted simultaneously from the light-emitting elements PY and PR, so that the speed of color discrimination can be greatly increased.

On the other hand, as shown in FIG. 4, when three types are used by using blue (B) light in addition to yellow (Y) light and red (R) light, multi-stage color discrimination is possible, and color discrimination close to full color is performed. Is performed. In this case, the amount of movement of the read head may be set to three times the interval (3a) between the light emitting fibers.

Although the above-described read head is of the shuttle type, it is needless to say that the read head can be applied to a serial type read head.

[Effects of the Invention] As described above in the embodiment, according to the image reading head of the present invention, the light quantity of each light emitting fiber is sufficiently ensured, so that the color discrimination accuracy is good. In addition, the problem of the layout design of the light emitting element and the light receiving element can be solved, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an image reading head according to one embodiment of the present invention, FIG. 2 is an external perspective view of an optical reading apparatus incorporating the reading head, and FIG. 3 is an operation state diagram of the image reading head. FIG. 4 is an operation state diagram of an image reading head according to another embodiment of the present invention, FIG. 5 is an electric control block diagram of a conventional image reading head, and FIG. 6 is a conventional image reading head with a color discriminating function. It is an operation | movement state diagram of. In the figure, 1 is a head substrate, Ti is a light emitting fiber, Ri is a light receiving fiber, LY and LR are light emitting elements, PY and PR are light receiving elements, 10 is an image reading head, and Y is a document.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yuya Inagaki 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Koichi Mino 1-16-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Yasufumi Takahashi, Examiner, Telegraph and Telephone Corporation

Claims (1)

(57) [Claims] A plurality of light-emitting fibers and the same number of light-receiving fibers corresponding to the light-emitting fibers are arranged in pairs on a head base, and a plurality of types of light having different wavelengths are provided on the head reading surface side of each light-emitting fiber. It is emitted from the end, the light emitting fibers emitting light of the same wavelength are spaced at equal intervals, and the light emitting fibers emitting light of different wavelengths are alternately spaced at a small interval that does not interfere with each other. An image reading head with a color discrimination function, which is arranged in a row on a head reading surface.