JPH0563907A - Color picture reader - Google Patents

Abstract

PURPOSE:To realize the color picture reader in which information quantity made incident on an image sensor from an original is enhanced and occurrence of color slurring is prevented. CONSTITUTION:A color reflecting mirror 9 having plural reflecting faces 11-14 having different colors is provided and when a reflected light from an original is made incident on an image sensor 15 by the reflecting faces 11-14 of the color reflecting mirror 9, the light is separated into colors by the reflecting faces 11-14. Since the reflected luminous quantity for the color separation reflecting faces 11-14 is set higher than the reflecting luminous quantity transmitted through the filter, the information quantity of the picture made incident on the image sensor 15 is set higher. Furthermore, since the color reflecting mirror 9 is formed integrally with the plural reflecting faces 11-14, the reflecting faces 11-14 are made standstill in a prescribed direction at a constant position by having only to decide the rotary angle of the color reflecting mirror 9 to prevent production of color slurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image reading device.

[0002]

2. Description of the Related Art First, a conventional example is shown in FIG. Reference numeral 1 denotes a transparent document table, and two carriers 3 and 4 are reciprocally provided along the lower surface of the document table 1. One of the carriers 3 holds a light source 6 for illuminating the original placed on the original table 1 and a mirror 7 for reflecting the reflected light from the original, and the other carrier 4 sequentially receives the reflected light from the mirror 7. A plurality of reflecting mirrors 8 and 32 are held. Further, a condenser lens 16 is provided in the optical path from the mirror 32 to the image sensor 15, and a plurality of filters 33, 34, 35, 3 which are individually color-coded for color separation.
A filter unit 37 having 6 is connected to a drive unit and is held so as to be vertically movable.

Therefore, in the process of moving the carriers 3 and 4 along the platen 1, the reflected light from the document on the platen 1 is reflected by the mirrors 7, 8 and 32, and further the filters 33, 34 and. Color separation is performed by 35 and 36, and an image is formed on the image sensor 15 by the condenser lens 16.

[0004]

For a color image, the carriers 3 and 4 are scanned a plurality of times, and filters 33 and 34,
Although color separation is performed by 35 and 36, the information amount of the image included in the reflected light from the document is reduced due to the influence of the light transmittance of the filters 33, 34, 35 and 36 themselves. Further, it is difficult to position the individual filters 33, 34, 35 and 36 on the same vertical plane, and moreover,
It becomes difficult to improve the switching accuracy of the vertical position of the filter unit 37, which causes color misregistration.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a light source for illuminating a document placed on a transparent document table, an image sensor, and a reflected light from the document are individually color-coded for color separation. A polygonal prism-shaped color reflecting mirror, which is rotatably supported with an axis along the main scanning direction, is formed on the outer peripheral surface of a plurality of reflecting surfaces that reflect toward the image sensor. The motor is configured to intermittently rotate at a rotation angle.

[0006]

When the reflected light from the original is incident on the image sensor by the reflecting surface of the color reflecting mirror, the color separation can be performed by the individual reflecting surfaces. Since the amount of light reflected by the reflective surface for color separation can be made higher than the amount of light reflected by the filter, the amount of information of the image incident on the image sensor can be increased. Further, since the color reflecting mirror for color separation has a plurality of reflecting surfaces integrally formed, it becomes easy to stop each reflecting surface in a fixed position at a fixed position only by determining the rotation angle of the color reflecting mirror. As a result, it is possible to prevent the occurrence of color misregistration.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The same parts as those described with reference to FIG. As shown in FIG. 1, carriers 3 and 4 are slidably held on guide rails 2 arranged along both sides of the lower surface of the document table 1. A part of the endless belt 5 running along the guide rail 2 is fixed to the carriers 3 and 4. The light source 3 and the mirror 7 are held on one carrier 3, and the mirror 8 and the color reflecting mirror 9 are held on the other carrier 4. This color reflecting mirror 49 has N (neutral), R (red), G (green), B (blue) on the outer peripheral surface for color separation.
A plurality of reflecting surfaces 11, 12, 13, which are color-coded for each color of
It is a quadrangular prism having 14 and is rotatably held with an axis along the main scanning direction. A condenser lens 16 is provided in the optical path between the color reflecting mirror 9 and the image sensor 15.
Is provided. The image sensor 15 is held on one surface of the substrate 17.

As shown in FIG. 2, one end of the color reflecting mirror 9 is directly connected to the motor 18, and the other end of the color reflecting mirror 9 has a plurality of through holes corresponding to the reflecting surfaces 11, 12, 13, and 14. 19
Is fixed, and a reflection type photo sensor 21 having a light emitting element and a light receiving element facing each other with the rotary encoder 20 interposed is provided.

Next, as shown in FIG. 3, an MPU (microcomputer processing unit) 22 and
A ROM 23 in which a program is written, a RAM 24 in which variable data is written, a timer 25 for counting the elapsed time after turning on the light source 6 and setting a reading start time, an interface 26, and a DMA.
C (Direct memory access controller) 2
7, the motor driver 28, and the image sensor 15
A / D converter 29 for converting the output from the digital signal into a digital signal
And an image RAM 30 for storing the converted digital signal (image data). A step motor 31 that drives the endless belt 5 to reciprocate the carriers 3 and 4 is connected to the motor driver 28, and a host computer is connected to the interface 26.

In such a structure, in the process of moving the carriers 3 and 4 along the platen 1 by rotating the endless belt 5 by the step motor 31, the reflected light from the document on the platen 1 is mirrored. 7 and the reflecting surface 11, 12, 13, 14 of the color reflecting mirror 9, and the image is formed on the image sensor 15 by the condenser lens 16. Then, every time the carriers 3 and 4 are scanned once,
By rotating the motor 18 by 90 ° and stopping the motor 18 when the photo sensor 21 detects the through hole 19 and switching the reflecting surfaces 11, 12, 13, 14 to be positioned in the optical path, the individual reflecting surfaces 11 , 12, 13, 14 can perform color separation. Since the amount of light reflected by the reflecting surfaces 11, 12, 13, 14 for color separation can be made higher than the amount of light reflected by the filter, the information amount of the image incident on the image sensor 15 can be increased. it can. Further, since the color reflecting mirror 9 for color separation has a plurality of reflecting surfaces 11, 12, 13, 14 integrally formed,
Only by determining the rotation angle of the color reflecting mirror 9, each reflecting surface 11, 1
It becomes easy to make 2, 13, 14 stand still at a fixed position in a fixed direction, and thus, color misregistration can be prevented.

[0011]

According to the present invention, a light source for illuminating a document placed on a transparent document table, an image sensor, and the light reflected from the document are individually color-coded for color separation to the image sensor. A polygonal prism-shaped color reflecting mirror that is rotatably supported with an axis along the main scanning direction and that has a plurality of reflecting surfaces that are reflected toward the outer surface, and this color reflecting mirror is interrupted at a predetermined rotation angle. Since it is composed of a motor that rotates the image, the reflected light from the original can be separated by each reflecting surface when it enters the image sensor by the reflecting surface of the color reflecting mirror. Since the amount of light reflected by the surface can be made higher than the amount of light reflected by the filter, it is possible to increase the amount of information in the image incident on the image sensor. Since the reflecting surface is formed integrally, it is easy to make each reflecting surface stand still at a fixed position and in a fixed direction simply by determining the rotation angle of the color reflecting mirror, which prevents the occurrence of color misregistration. It has the effect of being able to do so.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a rotation driving structure of a color reflecting mirror.

FIG. 3 is a block diagram showing an electronic circuit.

FIG. 4 is a front view showing a conventional example.

[Explanation of symbols]

 1 Document Plate 6 Light Source 9 Color Reflector 11-14 Reflective Surface 15 Image Sensor 18 Motor

Claims (1)

[Claims] 1. A light source for illuminating a document placed on a transparent document table, an image sensor, and color-separated individually for color separation, and reflected light from the document is reflected toward the image sensor. A polygonal prism-shaped color reflecting mirror having a plurality of reflecting surfaces formed on the outer peripheral surface and rotatably supported with an axis along the main scanning direction, and the color reflecting mirror is intermittently rotated at a predetermined rotation angle. A color image reading device comprising a motor.