JPS6335063A - Original reader - Google Patents

Abstract

PURPOSE:To simplify a switching mechanism for a color separation filter, by providing a filter switching mechanism for converting a rotation of a driving source to a reciprocating motion of the color separation filter by a cam. CONSTITUTION:When a stepping motor 11 is driven to rotate, a pulley 13 rotates in the direction as indicated with an arrow, this rotation is transferred to a pulley 10 through a belt 14, and a cam shaft 8, namely, a plate cam 9 rotated in the direction as indicated with an arrow. When this plate cam 9 rotates, a filter supporting plate 4 whose pin 6 contacts the peripheral surface of the plate cam 9 executes a reciprocating motion upward and downward, and accordingly, a color separation filter 2 executes a reciprocating motion upward and downward. In this way, the rotation of the driving source is converted to the reciprocating motion of the color separation filter by the cam, therefore, the constitution is simplified, and also, the inertial mass falls accordingly. In this way, the reciprocating motion of the color separation filter, namely, the color separation can be executed at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an original reading device for reading color originals.

A color document reading device that is generally used to read color documents in facsimile machines, copying machines, etc. (
As a color scanner, for example, there is one in which reflected light from a document is input to an image sensor through a color separation filter consisting of red, green, and blue filters.

In such a document reading device, for example, red, green, and blue color separation filters are formed in a stripe shape, and the color separation filters are held movably by an elastic member using, for example, a voice coil motor. It uses a near motor system to reciprocate vertically or horizontally (
(amplitude) and five color filters are sequentially placed in the optical path.

However, in order to increase the reciprocating speed of the single color separation filter, that is, the document reading speed, in order to change the filter by reciprocating the color separation filter using a linear motor method using the voice coil motor, it is necessary to use the voice coil motor. The need to improve the performance of the motor has made the mechanism more complex, and since a coil is required on the filter side, the inertial mass has increased, resulting in poor follow-up and the durability of the elastic member that supports the filter. There are inconveniences such as deterioration.

Purpose This invention has been made in view of the above points, and an object thereof is to simplify the switching mechanism of a single color separation filter.

In order to achieve the above object, the present invention includes a filter switching mechanism that converts rotation of a drive source into reciprocating motion of a color separation filter using a cam.

Hereinafter, a detailed explanation will be given based on one embodiment of the present invention.

FIG. 1 is a perspective view showing a first embodiment of the invention.

This document reading device includes a lens 1 (not shown) that reduces one line of reflected light from the surface of the document, and a lens 1 that enters the reflected light that passes through this lens 1 to read red.

Color separation filter 2 separates into green and blue.

A line image sensor 3 consisting of a CCD that receives reflected light that has passed through the color separation filter 2 and been separated into each color is sequentially arranged.

The color separation filter 2 is made up of striped red, green, and blue filters R9G and B arranged side by side on a holding plate 2a, and the end portions of the holding plate 2a are adhered to the filter support plate 4. ing.

Pins 6 are fixed to both sides of the filter support plate 4, and the pins 6 are slidably fitted into a guide 7 having a U-shaped cross section so as to be movable up and down. An elliptical plate cam 9 fixed to the camshaft 8 is disposed below the pin 6 of the filter support plate 4 as shown in FIG. I'm letting you do it.

Further, while the pulley 10 is fixed to one end of the camshaft 8,
Motor shaft 12 of stepping motor 11 as a drive source
A pulley 13 is fixed to the pulley 10, a belt 14 is stretched between these pulleys 10 and 13, and the plate cam S is rotated by the rotation of the motor 11.

Next, the operation of this embodiment configured as described above will be explained with reference to FIG. 3 as well.

By rotating the stepping motor 11,
The pulley 13 rotates in the direction of the arrow, and this rotation causes the belt 14 to rotate.
is transmitted to the pulley 10 via the camshaft 8, that is, the plate cam rotates in the direction of the arrow.

As the plate cam S rotates, the filter support plate 4, whose pins 6 are in contact with the circumferential surface of the plate cam S, reciprocates up and down, and therefore the color separation filter 2 reciprocates up and down.

At this time, each of the filters R2G and B of the color separation filter 2 is as shown in FIG. are located in the optical path, and the one-color separation filter 2 makes two reciprocations in one rotation of the plate cam S.

As a result, after the reflected light from the original passes through the lens 1, it is separated into the three colors red, green, and blue by the filters R, G, and B of the color separation filter 2 located in the optical path, and the line image sensor 3.

In this way, in this document reading device, the rotation of the drive source is converted into reciprocating motion of the color separation filter by the cam, so the configuration is simplified, and the inertial mass is reduced. It becomes possible to perform reciprocating motion, that is, color separation at high speed.

Further, as in this embodiment, the color separation filter 2 is held by pins 6 and guides 7 so as to be movable up and down.

Compared to the case where the color separation filter 2 is moved up and down by the contact between the temporary cam S and the pin 6, and the color separation filter 2 is held movably by an elastic member.

Stability, vibration resistance, and durability are also improved.

Although the pin 6 of the filter support plate 4 is brought into contact with the circumferential surface of the plate cam S under its own weight, the filter support plate 4 is urged downward by a spring or the like to forcibly move the pin 6 to the plate cam S. If it is pressed against the circumferential surface, stability etc. will be further improved.

FIG. 4 is a block diagram showing an example of a drive control circuit for the filter switching mechanism in this embodiment.

The stepping motor 11 is a driving source for vertically moving the color separation filter 2 as described above, and the stepping motor 11 is a driving source for vertically moving the color separation filter 2.
The rotation is driven by applying a drive pulse from the drive circuit 22 to the drive circuit 22.

On the other hand, stepping motor 2! Reference numeral 1 denotes a drive source for feeding the document, that is, for sub-scanning, and it rotates by applying a drive pulse from an oscillator 24 to a drive circuit 25.

This drive control circuit includes a synchronization signal circuit 26 for controlling each oscillator 21, 24 in order to synchronize the vertical movement of the color separation filter 2 and document feeding, that is, sub-scanning.

For example, assume that the number of pulses corresponding to the amount of rotation of the stepping motor 23 required to feed the original by one line is four pulses. On the other hand, in order to perform color separation using the color separation filter 2, red, green, and blue filters R and G are used for each line.

It is necessary to position the plate cam S in the optical path, and the above-mentioned plate cam S
When using the plate cam S, it makes two reciprocations in one rotation, so in order to perform color separation of one line, the plate cam S only needs to be rotated by 1/4 rotation.

Therefore, the stepping motor 11 for vertical movement of the color separation filter 2 is set to (-90°/motor step angle) = 1
By controlling the drive with the number of pulses for each line, it is possible to synchronize with sub-scanning (document feeding).

In this way, by converting the rotation of the drive source into reciprocating motion of the color separation filter using the cam, it is possible to synchronize the vertical movement of the color separation filter with the sub-scanning, thereby improving reading accuracy. Can be done.

FIGS. 5 and 6 are a side view and a plan view showing a second embodiment of the invention.

As shown in FIG. 7, the color separation filter 32 is composed of striped filters R, G, and B arranged horizontally.
This color separation filter 32 is attached to one end of an elastic arm 33 such as a plate spring, and the other end of this arm 33 is fixed to a support 34 to hold the single color separation filter 32 in a floating state.

Then, a plate cam 35 as shown in FIG. 8 is installed on a support shaft 36 rotatably disposed on the side of the middle part of the arm 33.
The side surface of the intermediate portion of the arm 33 is brought into contact with the peripheral surface of the plate cam 35. Note that the arm 33 is always in contact with the curved surface of the plate cam 35.

Further, the cam shape of the temporary cam 35 is such that the color separation filter 32 oscillates at a sine period. This is because, since the color separation filter 32 is held by an elastic body, vibrations are suppressed and the color separation filter 32 is smoothly reciprocated, thereby avoiding sudden changes in the direction of movement.

Note that this temporary cam 35 is the same as in the above embodiment.

It rotates by being transmitted with the rotation of a drive source such as a dedicated stepping motor or a stepping motor for document feeding.

Even in this case, the color separation filter 32 reciprocates left and right by rotating the plate cam 35 as in the above embodiment, and at this time, the red filter R is detected at eight points on the plate cam 3S shown in FIG. , green filter G is located in the optical path at point T, and blue filter B is located at point U, respectively. In this case, one rotation of the plate cam 35 causes the color separation filter 32 to
makes one round trip.

FIG. S is a plan view showing a third embodiment of the present invention, in which an arm 41 made of an elastic body with a color separation filter 32 attached to the end is formed into an L-shape, and the corner portion is rotatable with a support 42. The other end of the arm 41 is pressed into contact with the circumferential surface of the plate cam 35 by a plate spring 43.

In this embodiment as well, the color separation filter 32 reciprocates left and right as the plate cam 35 rotates, as in the second embodiment. Since the arm 41 is pressed into contact with the circumferential surface of the plate cam 35 by the plate spring 43, the arm 41 is securely pressed against the circumferential surface of the plate cam 35.
1 comes into contact with the peripheral surface of the plate cam 35, improving reliability.

FIG. 10 is a side view showing a fourth embodiment of the invention,
An arm 4 formed by bending the color separation filter 2 and made of an elastic body.
5, and the other end of this arm 45 is attached to the screw 4.
6 is fixed to a fixed part to hold the color separation filter 2 in a floating state, and a plate cam 35 is arranged below the middle of the arm 45.

Further, a tension coil spring 47 is coupled between one end of the arm 45 and the fixed portion to bring the arm 45 into pressure contact with the circumferential surface of the plate cam 35.

In this embodiment, as in the first embodiment, the rotation of the temporary cam 35 causes the color separation filter 2 to reciprocate up and down, and the spring 47 moves the arm 45 between the plate cams 35 and 35.
Since it is pressed against the peripheral surface, reliability is also improved.

As explained above, according to the present invention, the one-color separation filter can be moved back and forth with a simple configuration.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 are a perspective view showing a first embodiment of the present invention, a front view of its main parts, and a front view of a plate cam. FIG. 4 is a block diagram showing an example of the drive control circuit, and FIGS. 5 and 6 are a side view and a plan view showing a second embodiment of the invention. 7 and 8 are explanatory diagrams of the color separation filter and plate cam. FIG. S and FIG. 10 are a plan view showing a third embodiment of the present invention and a side view showing a fourth embodiment. 1... Lens 2, 32... Color separation filter 3
... Line image sensor 9.35 ... Plate cam 11 ... Stepping motor Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 187

Claims (1)

[Claims] 1. A document reading device that reads a color document by reciprocating a color separation filter, characterized in that it is equipped with a filter switching mechanism that converts rotation of a drive source into reciprocation of the color separation filter using a cam. Device.