JPS5837666A - Exchanger for color separating filter in color copying machine - Google Patents

Abstract

PURPOSE:To reduce weight by the use of dye filters and to deal with high speed revolutions and a change in humidity by the constitution wherein color separating filters are tied and held by means of transparent yarn to filter holding members which are fixed radially to a revolving shaft. CONSTITUTION:Three sheets of filter holding frames 32 are mounted to a shaft 30 via flanges 31, and dye separating filters 35 of blue, green and red having a rectangular strip shape are mounted to the frames 32. Only the short sides of the filters 35 are adhered to the frames 32, but the long sides are merely tied to the frames 32 by winding transparent nylon yarn 37 at suitable pitches, so that even when wind pressure is exerted upon the surfaces of the filters 35 during rotation the wind goes through the filters, whereby the exertion of exessive force upon the filters 35 is obviated. Even when the filters 35 elongate or contract by the effect of humidity, the filters do not deform or break.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color separation filter replacement device for a color electrophotographic copying machine.

In a color electrophotographic copying machine, three color separation filters, green and red, are usually replaceably installed in the image exposure path, and these filters are switched for each exposure to perform three exposures. , the extra color of the above filter (
By developing the images with yellow, magenta, and cyan developer and transferring them onto the same transfer paper, a color copy identical to the original can be obtained.

Conventionally, as shown in FIG. 1, the color separation filter replacement device described above is a disk-shaped filter fixing device in which three color separation filters 2 are provided on one circumference immediately before or after the copying lens l. The frame 3 is rotatably driven by a drive source 4 through a gear Ω mesh 4 to cut the frame 3, as shown in Fig. 2.
Three color separation filters 6 are placed along the slit exposure path 5.
The device V? is arranged such that the sheets are selectively inserted one by one into the exposure path 5 by a drive device (not shown). It has been known.

In all of these devices, it takes time to change the color separation filters, and the size of the device increases. ! 11) The former method has the drawback that the copying lens is limited to a through lens, and the installation location is also limited.

Further, as shown in FIG. 3, long strip-shaped color separation filters 8 are provided radially on one rotary shaft 7 in the axial direction, so that each of these filters can be switched and inserted into the exposure path 5. 17. Filter changing devices are also known.

The present invention relates to an improvement of this type of color separation filter replacement device.

As a prior art of this type of filter changing device 1't, for example, Japanese Patent Application Laid-Open No. 54-73058 discloses a color separation filter changing device for use in color copying and monochrome copying machines for blue, green, red and N- A device is shown in which four filters of utral density (D) are arranged in a cross shape as one TL (i).

N...D filter rP, for black and white. Among the four filters mentioned above, the first and third blue and second green filters are interference filters 9 which are made of a glass plate coated with layers of other substances, and the red and ND filters &:I:
1. Dyeing 1 made by dyeing a thin plate of Riacete 1 with dye
Filter 10 is used. When these filters are used in combination, the optical path conditions are different between the interference filter ′)Y, which is 1lTi:l, and 1(′1, where the light passes through the dyed Oni 1 filter). Therefore, interference filters 1' and 1' are inserted close to the red filter, N-1) filter, and the optical paths become the same. As a result, the structure becomes bulky and expensive, and the weight increases and the negative force of the driving source increases.

Dye-based filters made by dyeing thin plates such as triacetate 1 have good color separation performance and are very thin.
r7 (; Changes in resolution performance due to distortion of the filter at 1 o'clock, deterioration of imaging performance are small, and it is inexpensive, so it has been used for a long time, but it has been used for a long time. If you do this, the filter may fall off or be damaged due to the wind pressure, depending on how you install it, and also because the filter expands and contracts depending on the degree. There was a problem in that the four circumferences were fixed to the holding frame and the space was deformed.

In view of the above-mentioned drawbacks of the conventional color separation filter changing device, the present invention has been developed by arranging filters radially on the rotating shaft as described below, which is suitable for high-speed switching. It has a simple structure, which reduces the weight by adopting a filter retainer, which can easily be damaged due to high-speed rotation or changes in humidity. The purpose is to provide inexpensive color separation filter replacement!

Hereinafter, the present invention will be explained in detail with reference to the drawings showing an actual M1'r example.

FIG. 4 is a diagram showing an example of a color electrophotographic copying machine equipped with a color separation filter changing device according to the present invention.
The light C12 reflected by the original 13 irradiated by C12,
After being reflected by the first mirror 14 and the second mirror 5, -(
The light is converged and reflected by the mirror lens 16, and after being reflected by the third mirror 17, fourth mirror 18, and fifth mirror 19, an image is formed on the photoreceptor drum 2o. Scanning the original is
The light source 12 and the first mirror 14 move at the same speed from the position indicated by the solid line in the figure to the positions 12' and H' indicated by the chain line, and the second mirror I5 moves in the same direction at a speed of 1 (minutes). When you move, you will be transferred to the government office.

Between the third mirror 17 and the fourth mirror 18, a color 1f+ filter exchange device 21 according to the present invention is provided. In the color separation filter changing device 21, the three dyeing filters of blue, green, and red are replaced radially around the axis.The color separation filter changing device 21 is replaced in sequence according to the image forming process. 1; It is turning into a sea urchin. Is this how you change the filter? Sr'r;
This is done while the optical scanner returns to the normal position 11T (starting position) after forming one image. Filter switching must be performed at very high speed and in a short period of time. The filter is installed parallel to the slit optical path of the optical system and can be rotated in one direction.

v;1 around the photoreceptor drum 20, fjfM at the exposure position
Developing devices 22 , 28 , and 24 each holding three color developers of yellow, magenta, and cyan are provided, and the developer is sequentially developed in another developing device for each exposure fσ, and is fed from a paper feeding device 25. Transfer paper S wrapped around the transfer drum 26 and rotating
Transfer paper s kl: Transfer drum 2
It is peeled off from No. 6 and fixed by fixing device ff#27.
After that, it is placed on the tray 28 outside the machine, and the copying is completed.

As shown in detail in FIGS. 5 and 6, the color separation filter exchange device has three filter holding frames 32 fixed radially to flanges 31 at both ends of +ll+go by screws. The filter holder frame 32 is formed into a frame shape having an inner dimension slightly smaller than the dimension of the rectangular filter 35, and is attached with its longer side parallel to the axis. Boss 31a provided at the center of one flange 31
A filter drive 111I1133 is inserted into the hole,
The positioning pin 34 implanted in the drive shaft 33 is connected to the boss 31.
When it is engaged with the guide groove 311+ provided in a,
The rotation of the drive shaft 33 is transmitted to the filter 1111130, and the filter shaft 3o rotates in one direction shown by an arrow in the figure.

Each filter holding frame 32 is provided with one filter as shown in FIG.
1i', three rectangular dye-based color separation filters 35 of green and red are removed (= J is removed. In other words, the filter 3
5 glues only the short sides of both 4111+ to the corresponding positions of the holding frame 32 with double-sided adhesive tape, and the longer side is made to the same size as the nylon thread fixing screw 3 provided at the end of the holding frame 32.
Transparent nylon thread 37 with one end fixed to '6G'h
After winding the filter diagonally at a suitable pitch, the other end of the nylon thread is tied to the optical fixing screw provided at the other end of the holding frame 32 to secure the filter to the holding frame 32. Several notches 38 are provided on the long edges of the holding frame 32 for hooking and positioning the nylon thread 37. The appropriate thickness of this nylon thread is one equivalent to No. 1 to No. 3. In addition, in this embodiment, both ends of the filter 35 are glued to the holding frame 32 before being secured with the nylon thread 37.
If the filter is temporarily clamped to a holding frame by appropriate means and secured with nylon thread, the entire circumference of the filter can be non-adhered.

Suitable color separation filters include dl, such as Kodak's Wratten filter, Fuji Photo Film's bandpass filter, and sharp cut filter.
In the latter case, a BPB 45 can be used for the blue filter, an old B53 bandpass filter can be used for the green filter, and an lJ', SC60 sharp cut filter can be used for the red filter.

Filter switching d: As mentioned above, the filter 35 is changed at high speed, so that the filter 35 is not damaged or falls off from the holding frame due to the wind pressure applied to the filter 35 at the time of switching, as shown in FIG. The nylon thread 37 is in contact with the side of the holding frame 32 that is not exposed to wind pressure when it is rotated.
Even if wind pressure is applied to the surface of the filter 35 due to high-speed rotation during filter switching, a gap may be created between the filter 35 and the holding frame at the lower part of the filter, or in some cases at both ends, allowing air to escape and damage the filter. This prevents excessive force from being applied.

or ? ! ,,! J: Even if the refilter expands or contracts, the four circumferences are not glued, so the filter will not be deformed or damaged by excessive force.

In this case, V1, it is more convenient for the entire circumference of the filter to be non-adhesive.

As described above, according to the present invention, it is possible to obtain an inexpensive and reliable color separation filter switching device with a simple configuration.

[Brief explanation of the drawing]

1 to 3 C1 are sectional views each showing an example of a conventional color separation filter replacement device, FIG. 4 is a sectional view schematically showing an example of a color copying machine using the device of the present invention, and FIG. A perspective view of an embodiment of the present invention, FIG. 6 is a sectional view thereof, FIG. 7 is a perspective view showing a state in which the color separation filter is attached to a holding member, and FIG. 8 is a sectional view explaining the mounting direction of the DL filter. It is. 30...Rotation Qll+ 32...Filter holding member・X+1°

Claims (3)

[Claims] (1) A single rotary shaft is equipped with multiple dye-based color separation filters radially extending in the direction of the axis, and these color separation filters can be switched and inserted into various image exposure paths. In a color separation filter replacement device for a color electrophotographic copying machine, the above-mentioned color separation filter is fixed radially to a rotating shaft, and at least the long side opposite to the filter holding part is transparent and made of thread without being glued to the holding member. A color separation filter exchange device characterized in that the color separation filter exchange device is held in a fixed manner by the holding member. (2) The color separation filter replacement device according to claim 1, wherein the color separation filter is held with its four sides not fixed to the filter holding member. (3) A patent claim characterized in that the above-mentioned color separation filter is held on the surface of the holding part on the side where wind pressure is not applied when the color separation filter switching device rotates for filter switching. The color separation filter exchange device according to item 1 or 2.