JPS63109645A - Color picture reader - Google Patents

Abstract

PURPOSE:To attain accurate and sure synchronizing drive by delivering a torque of a color filter disk to a sub scanning mechanism via a reducing mechanism having a prescribed gear reduction ratio and driving the color filter disk and the sub scanning mechanism coupled with mechanical synchronizing means through a single motor. CONSTITUTION:The titled reader consists of the sub scanning device 14 applying sub-scanning to original paper 2, an image sensor 20 applying main-scanning to the original, a color filter disk 19 where plural filters with different filter band are arranged splittingly in the circumferential direction and the rotary locus of the filter is crossed with the incident optical path to the image sensor 20, a motor 21 driving the color filter disk 19 and the gear reducer device 22 reducing the output of the motor 21 by a prescribed gear reduction ratio and delivering it to the sub scanning device 14. Thus, two motors driven synchronously so far by the synchronizing means are abolished and the color filter disk 19 and the sub scanning mechanism 14 are driven synchronously accurately and surely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color image reading device that reads color images using an image sensor.

[Prior Art] Some color image reading devices used in color facsimiles, color copying machines, and the like use a one-dimensional image sensor as a photoelectric conversion means.

Conventional color image reading device shown in Figure 4! is disclosed in Japanese Patent Application Laid-Open No. 60-121874 ``Color Reading Device'', in which the original paper 2 is fed by a feed roller 4 driven by a pulse motor 3, and the belt hook is driven by the feed roller 4, which is interlocked with this sub-scanning. The configuration is such that main scanning is performed by sequentially driving each pixel of the image sensor 5. In this device, a three primary color filter 7 driven by a pulse motor 6 driven in synchronization with an image sensor 5 is oscillated between the image sensor 5 and a condensing lens 8, so that the light transmitted through the three primary color filter 7 is It is designed to read the color information of the read location. That is, it is configured to read color information by sequentially switching three primary color filters 7 in which three color filters of red (l, green (G), and blue (B)) are arranged radially in parallel with a certain width. There is.

[Problems to be Solved by the Invention] The conventional color image reading device 1 described above has a drive timing of the val smoke 3 for so-called sub-scanning for feeding the original paper 2 and a drive of the pulse motor 6 to switch the three primary color filters 7. It is necessary to constantly monitor these three timings so that the timing and the reading timing of the image sensor 5 are accurately linked, so the motor drive circuits 3a and 6a that drive each pulse motor 3. must be commonly controlled by a control circuit 9 that controls the reading of the images. Therefore, since two pulse motors 3.6 are used, the circuit configuration required for timing control tends to be complicated, and the manufacturing cost is also high.

[Means for Solving the Problems] The present invention solves the above problems, and the sub-scanning mechanism that sub-scans the original paper and the image sensor that main-scans the original have different wave bands. a color filter disk in which a plurality of filters are arranged in a divided manner in the circumferential direction, and provided so that the rotation locus of the filter intersects with the incident optical path to the image sensor; a motor for rotationally driving the color filter disk; The present invention is characterized by comprising a speed reduction mechanism that reduces the rotational output of the motor at a predetermined speed reduction ratio and transmits it to the sub-scanning mechanism.

[Operation] This invention uses a system in which the rotational power of the color filter disk is transmitted to the sub-scanning mechanism via a reduction mechanism having a predetermined reduction ratio, and the rotational power is transmitted to the sub-scanning mechanism by a single motor and mechanical synchronization means. By driving the color filter disk and the sub-scanning mechanism, the two motors that were previously rotated synchronously by the synchronizing means are eliminated, and the color filter disk and the sub-scanning mechanism are accurately and reliably driven synchronously. It is something.

[Embodiments] Examples of the present invention will be described below with reference to FIGS. 1, 2 and 3. FIG. 1 is a perspective view showing a schematic configuration of an embodiment of a color image reading device of the present invention.

In Figure 1, a color image reading device! ■ is a rectangular frame-shaped document table 12 that is set so as to cover the top of the document paper 2.
It has a sub-scanning mechanism 14 in which a self-propelled conveyance platform 13 that moves in the sub-scanning direction is assembled. Inside the transport table 13, there is a fluorescent tube that irradiates light onto the manuscript paper 2 below the manuscript table 12! 5. Fluorescent tubes! Two reflecting mirrors 16 and 17 are arranged in a predetermined positional relationship to change the optical path of the light emitted from the original paper 2 by reflection. Also, reflector +6°I7
a condensing lens 18 that condenses the light sequentially reflected by the
An image sensor 20 receives reflected light collected by a condensing lens 18 via a color filter disc 19, or a motor 21 that rotationally drives the color filter disc 19 and the rotational output of the motor 21 is reduced to a predetermined reduction ratio. So slow down,
A gear reduction mechanism 22 and the like that transmits data to the sub-scanning mechanism 14 are also incorporated into the conveyance table 13 .

The color filter disk 19 has RGB3 having different wave bands.
A plurality of primary color filters 19r, 19g, 19b are divided and arranged in the circumferential direction, and each filter 19r, 1
The rotation trajectories 9g and 19b intersect the incident optical path to the image sensor 20. Therefore, the light collected by the condenser lens 18 passes through any one of the filters 19r, 19g, and 19b and reaches the image sensor 20. In the gear reduction mechanism 22, a drive gear 23 is fitted and fixed to a rotating shaft 21a of a motor 21 to which a color filter disk 19 is fixed at the tip, and large and small gears coaxially control the rotation of the drive gear 23. The signal is transmitted to the pinion 26 via two integrated reduction gears 24 and 25, and the rack 27 that meshes with the pinion 26 is relatively linearly driven. In this embodiment, the rack 27 is embedded in the top side of the document table 12 along the conveyance direction of the conveyor table 13, so that the conveyor table 13 moves in the sub-scanning direction as the motor 21 rotates. The reduction ratio of the gear reduction mechanism 22 is set to an appropriate ratio in consideration of the aperture ratio of the condenser lens 18, the division pitch of the filter of the color filter disk 19, and the like.

Here, the manuscript table! Assume that a document sheet 2 to be image read is set on the bottom surface of the document sheet 2, and the motor 21 is started. When the motor 21 is activated, the color filter disk 19 rotates, and at the same time, the conveyance table 13 begins to move slowly. The image drawn on the original paper 2 is irradiated with light emitted by the fluorescent tube 15, and is repeatedly reflected by the reflecting mirrors 16 and 17, and then enters the condenser lens 18. The light collected by the condenser lens 18 passes through the color filter disc 19 and forms an image on the image sensor 20 . As a result, the color filter disk I
Filters 19r and 19g that actually use a rotation period of 9
, 19b, each color of RGB is read one after another. Therefore, not only the rotation of the color filter disk 19 and the driving of each pixel of the image sensor 20 are performed in synchronization, but also the movement of the conveyance table 13 is performed in synchronization with them by the gear reduction mechanism 22. As a result, image reading of three colors of RGB by the image reading device 11 is performed accurately and reliably.

In this way, the color image reading device 11 has a configuration in which the color filter disk 19 and the sub-scanning mechanism 14, which are connected by mechanical synchronization means, are driven by a single motor 21. and sub-scanning mechanism 1
4 can be accurately and reliably synchronously driven, thereby allowing the main scanning to drive each pixel constituting the image sensor 20, the sub-scanning to move the conveyance table 13 relative to the original paper 2, and the color filter disk 19. The three rotational drive operations can be well controlled in an integrated manner.

In the above embodiment, the so-called self-propelled color image reading device 11 in which the conveyance table 13 moves with respect to the stationary manuscript paper 2 was taken as an example, but for example, the color image reading device 31 shown in FIG. It is also possible to have a configuration in which the image sensor 20 for main scanning is fixed, and the document paper 2 is moved to perform sub-scanning. The color image reading device 31 is provided with a feed roller 33 having a gear 32 fixed to the shaft end that meshes with the pinion 26, and a guide roller 34 that abuts the feed roller 33. A plurality of guide rollers 34 are arranged at appropriate intervals from each other so as to be able to press several places on the upper surface of the manuscript paper 2, and the manuscript paper 2 is held between the feed roller 33 and the guide roller 34. Moving. In the case of this embodiment, the path of the light from being reflected on the original paper 2 to reaching the image sensor 20 is slightly different from that of the previous embodiment, but by changing the optical path with the two reflecting mirrors 16 and 17. The aim is to save space in the optical system.

In addition, the gear reduction mechanism 35 in this case includes the drive gear 23,
It is composed of reduction gears 24', 25, pinion 26, gear 32, etc., and by adjusting the size of the outer diameter of the feed roller 33, the feeding speed of the manuscript paper 2 can be changed.
Therefore, the gear reduction mechanism 35 and the feed roller 33 constitute the reduction mechanism described in the claims. Note that calculation of the reduction ratio required for the gear reduction mechanism 35 is basically the same as in the previous embodiment.

Furthermore, instead of using two reflecting mirrors 16 and 17 as in the color image reading device If, 31, for example, a third mirror can be used.
It is also possible to change the optical path using one reflecting mirror 42, as in the color image reading device 4I shown in the figure. The illustrated color image reading device 41 has a fluorescent tube 1 placed directly above a document paper 2 held between a pair of feed rollers 43 and 44.
5 is arranged so that the light reflected on the original paper 2 enters the condenser lens 18 via the reflecting mirror 42. A color filter disk 19 interposed between the condenser lens 18 and the image sensor 20 is rotationally driven by a directly connected motor 21 . The rotating shaft 212L of the motor shaft 21 includes
A small diameter pulley 45 is fitted and fixed, and the rotational power of the motor 21 is decelerated and extracted by a large diameter pulley 47 connected to the pulley 45 by a belt 46. A bevel gear 49 is fixed to the tip of the shaft 48 of the pulley 47.
A bevel gear 50 that meshes with this bevel gear 49 is connected to the feed roller 4.
It is coaxially fixed to 3. Therefore, the feed rollers 43 and 44
The original paper 2 is rotated in synchronization with the rotation of the color filter disk I9.
can be sent. As can be seen from this example,
When using a single reflection m42, the image sensor 20
In determining the optical path leading to the fluorescent tube 15, it is necessary to arrange the image sensor 20 to directly face the fluorescent tube 15. As a result, the rotation transmission system of the motor 21 requires means for orthogonally converting the rotation transmission direction, but in this embodiment, a pair of bevel gears 49.
50 fulfills the role of deceleration and direction change, thereby meeting this demand, simplifying the overall configuration of the device and improving the space factor. Note that the speed reduction mechanism described in the claims includes pulleys 45, 47 and belt 46.
and a gear reduction mechanism 51.

[Effects of the Invention] As explained above, the present invention transmits the rotational power of a color filter disk that filters a color image by color to a sub-scanning mechanism via a speed reduction mechanism having a predetermined speed reduction ratio, Since the color filter disk and sub-scanning mechanism, which are connected by mechanical synchronization means, are driven by a single motor, multiple pulse motors are synchronously rotated by a motor drive circuit monitored by a common control circuit. It is possible to accurately and reliably synchronously drive the three pixels that make up the image sensor, sub-scanning for the document paper, and rotationally driving the color filter disk. This provides excellent effects such as good overall control.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the schematic structure of one embodiment of the color image reading device of the present invention, and FIGS. 2 and 3 are perspective views showing the schematic structure of other embodiments of the color image reading device of the present invention. 4 are schematic configuration diagrams showing an example of a conventional color image reading device. 211. Manuscript paper, 11, 31, 41. ,,color image reading device,14. ,,sub-scanning mechanism. 19., color filter disk, 20. ,,image sensor,21. , , motor, 22. ．． 35°St, gear castle speed mechanism, 33. ．． ．． feed roller. 45.47. ,, pulley, 46. ,,belt.

Claims (1)

[Claims] A sub-scanning mechanism for sub-scanning the original paper, an image sensor for main-scanning the original, and a plurality of filters having different filtering bands are arranged in a divided manner in the circumferential direction, and a rotation locus of the filter is arranged in the optical path of incidence on the image sensor. Color filter disks arranged to intersect with each other, a motor that rotationally drives the color filter disks, and a speed reduction mechanism that reduces the rotational output of the motor at a predetermined speed reduction ratio and transmits it to the sub-scanning mechanism. A color image reading device consisting of: