JPH01246507A - Color separation filter device - Google Patents

Abstract

PURPOSE:To simplify the structure of the above device and to facilitate assembling and adjusting operations by adhering plural pieces of filters for monochromatic light onto a common transparent base body. CONSTITUTION:The filter FB for blue light, the filter FG for green light and the filter FR for red light are arrayed on the same plane of a transparent glass plate G having optical parallel planes as the common transparent body. The filter FND having the prescribed transmittance to visible light by cutting UV light and IR light is arrayed in the transverse direction thereof and these filters are respectively adhered to the glass plate by balsam and are thereby integrated. Handling of the respective filters for monochromatic light as one single member is thereby enabled. The color sepn. filter device which is simple in the structure of the device and allows the easy assembly and adjustment operations is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color separation filter device used in an image reading system of a multicolor image forming apparatus or the like.

[Background of the invention]

A multicolor image forming apparatus, especially a digital multicolor image forming apparatus, is generally composed of color image processing devices such as an image reading section and an image writing section. The light is passed through an imaging lens system for reading, and conventionally, it is split into multiple lights by a light splitting means such as a prism installed behind it, and the light is imaged on a solid-state imaging device such as a CCD that receives the light in each channel. The method is to take out an image signal corresponding to the image and input it to the image writing section mentioned above.

[Problem that the invention seeks to solve]

A prism block or the like is used as the light splitting means described above, but it requires several expensive CODs, which is difficult in terms of price structure, and it is troublesome to adjust the positions and performance of the CCDs. A method has been proposed in which a plurality of convertible monochromatic light filters are placed in front of or behind the imaging lens system instead of the light splitting means, and the transmitted light is sequentially received by a common CCD to obtain an image signal cycle. ing.

Since the CCD itself is small, each monochromatic light filter does not need to be large in size, but since each filter is manufactured and installed individually, it is always perpendicular to the optical axis of the imaging lens system. It is difficult to install, and the structure is complicated, making it difficult to assemble.

As a result of solving this problem and improving the present invention, the plane of each monochromatic light filter is always perpendicular to the optical axis of the imaging lens system.
The object of the present invention is to provide a color separation filter device that can be directly faced, has a simple structure, and can be easily assembled and adjusted.

[Structure of the invention]

The above object is achieved by a color separation filter device characterized in that the color separation filters provided on the same plane are constructed by bonding a plurality of monochromatic light filters onto a common transparent substrate.

〔Example〕

Embodiments of the invention are shown in FIGS. 1-5.

FIG. 1 shows the main configuration of a multicolor image forming apparatus equipped with a color separation filter device of the present invention, in which A is an image reading system;
B is each unit of the laser writing system or C is the image forming section,
D is a paper feeding section, in which a color image is formed through the following process.

In the reading system A, 11 is a document table;
The document contained in the document is mounted on a carriage 12 that slides horizontally and is illuminated by a halogen lamp 13. The movable mirror unit 15 includes mirrors 16 and 1.
7 is attached and also slides horizontally,
In combination with the mirror 14 attached to the carriage 12, the optical image of the document is guided to the lens reading section 20.

The carriage 12 and the movable mirror unit 15 are connected to a stepping motor by wires (none of which are shown).
, and slide in the same direction at speeds of V8 and 1/2V, respectively.

The lens reading section 20 includes a lens barrel 2L, a color separation filter device 22, and a CCD 23.

The optical image of the original transmitted by the mirrors 14, 16 and 17 sequentially passes through each of the blue, green, red and ND filters constituting a color separation filter F (described later) of the color separation filter device 22, and passes through the lens barrel. 21, and an image is formed on the light receiving surface of the CCD 23 provided on the reading board 24.

Therefore, when exposing the surface of one document, scanning is performed four times by the carriage 12 and the movable mirror unit 15, and in synchronization with this, the color separation filter device 22 scans each filter of the color separation filter F described above. A conversion will take place.

The light image is thus blue, green, red and neutral (ND
) Each image signal output from the CCD 23 corresponding to the filter is subjected to signal processing in a signal processing section. In the signal processing section, shading correction, gradation correction, and dither processing are performed, and color signals separated by color according to the color separation filter are output and input to the laser writing system unit B, which is an exposure means.

In the laser writing system unit B, a laser beam generated by a semiconductor laser (not shown) is rotated and scanned by a polygon mirror 32 rotated by a drive motor 31, passes through an Fθ lens 33, and has its optical path bent by a mirror 34. , is projected onto the circumferential surface of the image carrier 3o to which a charge has been applied in advance by a charger 35 serving as a charging means to form a bright line.

On the one hand, when scanning is started, the beam is detected by an index sensor, and modulation of the beam by a first color signal, for example an image signal passed through a blue color separation filter, is started, and the modulated beam is transferred to the image carrier 30. scan the circumferential surface of the Therefore, the main scanning by the laser beam and the image carrier 3o
A latent image is formed on the circumferential surface of the image carrier 30 by the sub-scanning caused by the rotation of the image carrier 30 . This latent image is developed by a developing device 36Y loaded with yellow toner in the developing means, and a toner image is formed on the drum surface. The obtained toner image, while being held on the drum surface, passes under a cleaning device 39, which is a cleaning means, which is separated from the peripheral surface of the image carrier 3o, and enters the next copy cycle.

That is, the image carrier 3o is charged again by the charger 35, and then a second color signal outputted from the signal processing section, for example, an image signal passed through a green color separation filter, is transferred to the writing system unit l-B. In the same way as the image signal described above, writing is performed on the drum surface to form a latent image. The latent image is developed by a developer 36M loaded with magenta toner as a second color.

This magenta toner image is formed in the presence of the previously formed yellow toner image.

Similarly, 36C and 36BK are developing devices having cyan toner and black toner, respectively, and cyan and black toner images are formed on the drum surface corresponding to the red filter and neutral filter based on the control signal generated by the signal processing section. form.

AC and DC biases are applied to the sleeves of each of the developing devices 36Y to 368, and non-contact development is performed using a two-component developer serving as a developing means. Development is performed without destroying the toner image.

The color image thus formed on the circumferential surface of the image carrier 30 is transferred from the paper feed section to the paper feed belt 41 at the transfer pole 40 provided as a transfer means. The image is transferred onto recording paper, which is a recording medium, fed by the feeding roller 42. The recording paper onto which the toner image has been transferred is separated from the drum surface by a separation pole 43 and conveyed to a fixing device 45 via a conveyor belt 44, where the image is fixed.

On the other hand, the blade 39A of the cleaning device 39 comes into contact with the image carrier 30 from which the recording paper has been separated from the drum circumferential surface to remove the remaining toner, and after that, the image carrier 30 is separated from the drum circumferential surface again. A new color image formation process begins.

FIG. 2 shows the structure of the lens reading section 20, in which the lens barrel 21 is housed in a 7-shaped receiver that opens at right angles toward the upper side of the holding member 21A, and is housed in a fastener 21B.
and is attached to the device board of image reading system A.

Further, the color separation filter device [t22 is the color separation filter F]
It is composed of a filter frame 22A that houses the filter frame 22A and slides intermittently in a direction perpendicular to the plane of the paper, and a frame 22B that incorporates a servo motor M that transmits power to the filter frame 22A. Member 21A
It is attached to the rear end surface of the

Furthermore, the CCD 23 is fixed together with the reading board 24 to the upper part of the rear end surface of the complimentary member 21A via a fixing member 23A by adhesive means or the like.

Note that when installing the color separation filter device 22 and the CCD 23, the flat part of the color separation filter F and the CCD 23 should be
The light-receiving surfaces of the lens barrel 21 are adjusted and fixed so that they are aligned with each other while remaining perpendicular to the optical axis of the lens barrel 21.

The color separation filters F are arranged on the same plane of a transparent glass plate G having optically parallel planes as a common transparent substrate, as shown in FIG. 5(a), (b), and (c). There are three monochromatic light filters having specific transmission wavelength regions as shown, namely, a blue light filter FB1 and a green light filter F. A filter FR for red light and a filter FND as shown in Fig. 5(d) which cuts ultraviolet light and infrared light and has a predetermined transmittance for visible light are arranged horizontally and glued together with Pulsam. It is made into a single unit by integrating the two.

Therefore, the planes of each filter are aligned with high precision, and even if filter conversion is performed, each filter can always maintain accurate perpendicularity to the optical axis of the lens barrel 21. In addition, monochromatic light filters such as Z nS
, M9F x by vacuum deposition, the transparent glass plate G also produces the effect of a cover glass by using the interference filter surface as an adhesive surface.

Furthermore, since the color separation filter F is made into a single unit, the structure of the filter frame 22A is simplified, and therefore, the installation and adjustment of the filter can be done easily.

As shown in FIG. 4, the color separation filter F is housed in the filter frame 22A, and is ensured to prevent optical distortion by a holding spring plate 22D having holes in the effective area of each filter surface. Retained.

The lower surface of the filter frame 22D engages with the rail on the upper surface of the pedestal 22B, and is attached so that the color separation filters F can be slid in the direction in which the filters are arranged. is meshed with a pinion P on the shaft of a servo motor M built in the frame 22B.

The servo motor M is intermittently energized by a signal from a control unit synchronized with the exposure process of the document surface, and can accurately move each of the above-mentioned filters onto the optical axis of the lens barrel 21 and place them in a stopped state. Note that it is of course possible to use a pulse motor instead of the servo motor and move the filter in synchronization with the exposure process by controlling the number of pulses by the control section.

Further, when one cycle of latent image formation by exposure is completed, a return operation is automatically performed to position the filter F8 again at the initial position, that is, on the optical axis.

〔Effect of the invention〕

According to the present invention, the monochromatic light filters constituting the color separation filter can be used while being accurately aligned on the same plane, and each monochromatic light filter can be handled as one single member, so the structure of the device is Thus, a color separation filter device is provided which is simple and requires only a small number of parts and simple work for installation and adjustment.

[Brief explanation of the drawing]

1 and 2 are block diagrams and main parts of a multicolor image forming apparatus equipped with a color separation filter device of the present invention, FIG. 3 is a perspective view of the color separation filter device, and FIG. 4 is a diagram showing the color separation filter device of the present invention. FIG. 5 is a block diagram of the separation filter device, and a graph showing the transmission wavelength characteristics of each monochromatic light filter and ND filter constituting the color separation filter. 21... Lens barrel 21A... Holding member 22... Color separation filter device 22A... Filter frame 22B... Mount 22
C... Bracket 22D... Presser spring plate 2
3...CCD F...Color separation filter G...Transparent glass plate F B+ F G, F B+ F ND... Monochromatic light (
Blue, green, red) and ND filter R...Rack P...Pinion M...Servo motor

Claims (1)

[Claims] 1. A color separation filter device, characterized in that the color separation filters provided on the same plane are constructed by bonding a plurality of monochromatic light filters onto a common transparent substrate.