JPS60127863A - Color original reader - Google Patents

Abstract

PURPOSE:To attain miniaturization and ease of focus adjustment by arranging a color separation element to the image forming lens side to eliminate the need for the use of a long back focus as the image forming lens and focusing at each image forming lens. CONSTITUTION:The reflected light from the color original O is separated by dichroic mirrors 3, 5 with a color separating means and separated into red, blue and green color component flux. The separated each color flux should be shifted so as not to be overlapped with each other and made incident to the image forming lenses 8-10. Thus, it is required to shift each color separation flux by at least one image forming lens' share, and the shift of the luminous flux is realized easily by the adjustment of the relative position relation of the dichroic mirrors 3, 5 and flat mirrors 4, 6 and 7.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a color document reading device.

(Prior Art) Various types of color document reading devices are known in the past that separate color documents into three primary colors and read them.

Conventionally known color document reading devices generally use a single imaging lens to image the □□□ of the color document reading section, and direct the optical path of the imaging light beam to the □□□ of the imaging lens. It is divided into 6 parts on the side, each of the 6 parts of the imaged light beam is guided to the corresponding solid-state image sensor, and focused on the light receiving area, and each of the 6 parts of the imaged light beam is subjected to color separation. That is what it is. Such conventional color document reading devices have the following problems.

That is, the light-receiving area length of the solid-state image sensor is smaller than the reading width of the document. Therefore, the condensation due to imaging/zoom has a reduction magnification. Therefore, the optical path length between the imaging lens and the solid-state image sensor is shorter than the optical path length on the object side of the imaging lens. However, since it is necessary to install an optical system for splitting the optical path and a color separation means on the image side of the lens, it is necessary to use a lens with a long bank focus as the imaging lens. The equipment becomes bulky and the size of the device increases.

In addition, since a single iris lens focuses images on multiple solid-state image sensors, focusing is difficult and cumbersome.

(Objective) Accordingly, it is an object of the present invention to provide a novel color document reading device that effectively solves the above-mentioned problems.

(composition) The present invention will be explained below.

The color document reading device of the present invention is a device that separates and reads a color document into three primary colors α, β, and γ.
It has a J lens and color separation means.

The illumination scanning means scans the original, i.e. the color original to be read;
Scan the IJ with illumination.

One of the six solid-state image sensors photoelectrically converts an image separated into alpha colors. Another one photoelectrically converts an image 1' separated into β colors, and the remaining one photoelectrically converts an image separated into gamma colors.

The six imaging lenses include six solid-state image sensors,
In correspondence with each other, the image of the color document reading section is formed on the light receiving area of the corresponding solid-state imager.

The color separation means separates the light from the color original into six primary colors α.

Color separation into β and γ. This color separation element is arranged on the object side of the six imaging lenses.

-Illumination scanning of the original is performed for a color original placed in a fixed position.
The illumination optical system may be moved, or the color original may be moved relative to the illumination optical system, or both the illumination optical system and the color original may be moved, and the relative displacement of the two may be utilized. Illumination scanning may also be performed using

As the solid-state image sensor, a so-called COD, BBD, etc. can be used.

As the color separation means, a dichroic mirror or a color filter shade can be used.

The following is a description of a specific example.

In the example shown in Figure 1, code 0 indicates a color manuscript,
Reference numeral 1 is a document placement crow, reference numeral 2 is an illumination lamp, reference numeral 6 is a dichroic mirror, reference numerals 4, 6.7 are plane mirrors, reference numeral 5 is a dichroic mirror, reference numerals 8, 9, .
10 is an imaging lens, and reference numeral 11. 12. 13 is
A solid-state image sensor is shown in each figure.

A color document O having color information to be read is placed flatly on the document placement glass 1 with the surface having the color information facing downward.

In this example, it is assumed that the three primary colors α, β, and γ are red, green, and blue, respectively.

Now, when the illumination lamp 2 is turned on in the state shown in Fig. 1, since the illumination lamp 2 is a tube lamp whose longitudinal direction is orthogonal to the drawing, the color document portion above the illumination lug will be It is illuminated through the document placement glass 1 in the form of a slit whose longitudinal direction is perpendicular to the drawing.

The reflected light from the color original o first enters the dichroic mirror 6. The dichroic mirror 6 has an optical property of reflecting red light and transmitting light of other colors. Therefore, the red light component of the light incident on the dichroic ink mirror 3 is reflected to the right by the dichroic mirror 6, and the components of other colors are transmitted through the dichroic ink mirror 3.

The red light component reflected by the dichroic mirror 6 is then reflected by the plane mirror 6.7, and is then reflected by the imaging lens 9.
, and this image is formed by 7 zooms 9 to form a reduced image of the illuminated portion of the color document ◯ at f8.

A solid-state image sensor 12 is placed at the position of the image plane of this reduced image.
This means that it is being deployed.

On the other hand, the light transmitted through the dichroic mirror 2 is reflected by the plane mirror 4 and then enters the dichroic mirror 5. The dichroic mirror 5 has an optical property of reflecting the blue light component of the incident light and transmitting light of other colors.

Therefore, of the light incident on the dichroic mirror 5, the blue light component is reflected by the dichroic mirror 5, and the green light component is transmitted through the dichroic mirror 5.

The blue light component reflected by the dichroic mirror 5 is reflected by the plane mirror 7 and then enters the imaging lens 10. A solid-state image sensor 16 is arranged so as to match the imaging plane of the reduced image. ing.

The green light component transmitted through the dichroic mirror 5 is then reflected by a plane mirror 6.7, forms an image, and enters a lens 8, where a reduced image is formed by the action of the lens 8. A solid-state image sensor 11 is arranged so as to match the imaging plane of this reduced image.

The solid-state image sensors 11, 12, and 13 have the same structure, and are made by arranging and integrating minute light-receiving elements in one direction at minute intervals, and providing a self-scanning function. In a solid-state imager, the area where minute light-receiving elements are arranged is called a light-receiving area.

The direction in which the light receiving elements are arranged is referred to as the longitudinal direction of the light receiving elements. Since the light receiving element is extremely small, the light receiving area is linear. In Fig. 1, ° solid-state image sensor 1
t, 12. The light receiving area of 13 is in the direction perpendicular to the drawing.

As mentioned above, solid-state image sensors 11, 12゜16
are arranged to coincide with the image plane of the reduced image of the color original O by the imaging lenses 8, 9, and 10, respectively.
As is clear from Figure 1, solid-state image sensor-1
Each of the light receiving areas 1, 12, and 13 corresponds to a portion of the color original O indicated by the symbol pl. This portion P is a linear region whose longitudinal direction is perpendicular to the drawing. As can be easily understood from the above explanation, the reduced image of this linear region P is for each solid-state image sensor 11, 12,
The image is focused on 13 light receiving areas. So, the linear region P is i
It is called Toribe.

Now, as mentioned earlier, the imaging lenses 8, 9, and 10 are filled with the green light component, the green light component, and
Since the red light component and the blue light component are incident, the reduced image formed in the light receiving area of the solid-state image sensor 11, 12゜13 is the color separation of green, red, and blue of the reading section P. . Therefore, each solid-state image sensor-11, 12,
By driving 13, the six primary color separation images of the reading section P can be converted into electrical signals. Therefore, by repeatedly driving the solid-state image sensors 11, 12, and 13 while scanning the color original Q to the right in FIG. 1, the color original ○ can be separated into six primary colors and read.

As mentioned above, there are various methods for scanning the color original O, but here, a case where the color original is moved and a case where the color original is not moved will be explained.

When moving the color original O, the color original 0 is moved to the left in the fan 1 diagram with respect to the original placing glass 1 using an unillustrated original conveying means.

In this case, the other optical systems do not move.

In such a scanning method, the illumination lamp 2 and the document conveyance means (not shown) constitute illumination scanning means. Further, the dichroic mirrors 6 and 5 constitute color separation means 411.

In order to scan the color original O without moving it, the illumination lamp 2, dichroic mirror 6, and plane mirror 4 are integrated, and they are displaced to the right at a constant speed (2). At the same time, the dichroic ink mirror 5 and the plane mirror 6.7 are integrated, and the speed is 1/2 of the moving speed of the illumination lamp 2, etc.
In other words, it is sufficient to move it to the right at 1/2V.

In this case, illumination lamp 2. dichroic mirror 6
．． 5. The plane mirrors 4, 6, 7 and the mechanism for moving these constitute illumination scanning means, and dichroic mirror 6.5 serves as color separation means and also forms part of the illumination scanning means. becomes.

In Figure 1, the reflected light from the color original 0 is passed through a dichroic mirror 3. as a color separation means. 5, and is separated into red, blue, and green color component light beams. The color component light beams separated from each other in this manner must be shifted so as not to overlap each other and then enter the imaging lenses 8, 9, and 10. For this purpose, it is necessary to shift each color-separated light beam from each other by at least the pupil of the imaging lenses 8, 9.10. This can be easily achieved by adjusting the relative relationship between companies.

Figures 2 and 6 show two other examples of using dichroic mirrors as color separation means.

Please note that to avoid complications, color originals should be 0. Manuscript placed fff
Glass 1, illumination rung 2, imaging lens 8,9゛10,
Regarding the solid-state image sensors 11, 12, and 13, the same reference numerals as in Fig. 1 are used in the drawings after Fig. 2. In addition, in the drawings below 2. 9. Only 10 optical axis rays are shown.

In the actual case shown in Fig. 2, 14.15 is a dichroic mirror, and 16.15 is a dichroic mirror. 17. 18 indicates a plane mirror.

Assuming that each of the dichroic mirrors 14 and 15 has the same optical function as the dichroic mirror 6.5 shown in FIG. The resolved image and the green resolved image are solid-state image sensors 12 and 1, respectively.
1 is converted into an electrical signal.

In the actual case shown in Figure 6, 20.21 is a dichroic ink mirror, and 19.21 is a dichroic ink mirror. 22. 23 indicates a plane mirror. Assuming that the dichroic mirrors 20.21 each have the same optical function as the dichroic mirror 6.5 in Figure 1, the red separated image, blue separated image, and green separated image of the color original O are solid. The image sensors 15, 12, and 11 convert the signals into electrical signals.

In the actual case shown in Fig. 4, 24.25 is a semi-transparent mirror, and 19.25 is a semi-transparent mirror. 22. 23 is a plane mirror, code 26゜2
7.28 indicates a filter.

The semi-transparent mirror 24 has the function of reflecting 1/6 of the incident light and transmitting 2/6 of the incident light, and the semi-transparent mirror 25 has the function of transmitting 1/2 of the incident light and reflecting 1/2 of the incident light. . Therefore, the original color original is separated by the semi-transparent mirrors 24 and 25 into six light beams that are equal in intensity, and each of the light beams separated in this way is filtered through the filters 26 , 27 ,
28 to the condensation lens 8.9.10.
If a green light transmitting filter is used, each light beam is separated into colors by passing through these filters 26.27°28. Therefore, a red separated image and a blue separated image of the color original O.

The green parts are solid-state image sensors 11 and 11, respectively.
It is converted into an electrical signal by 12 and 13. In this example, semi-transparent mirrors 24, 25 and filters 26, 27° 28 constitute the color separation means.

In any of the actual cases shown in Figure 2, Figure 3, and Figure 4, the document moving method or the fixed source tank method is possible.

(Effects) As described above, according to the present invention, a novel color document reading device can be provided. In this color document reading device, since the color separation element is arranged on the object side of the lens, there is no need to use a lens with a long bank focus as the imaging lens. Therefore, the reading device can be downsized. %
Furthermore, as the imaging lens, a lens with a short bank focus, which has been conventionally used for reading black and white originals, can be used as is.

Furthermore, since bit alignment is carried out separately for each imaging lens, it can be carried out extremely easily.

[Brief explanation of the drawing]

Figure 1 is a front view schematically showing only the affected part of one actual case of the present invention, Figure 2 is a front view schematically showing only the essential parts of another actual case of the present invention, and Figures 1-6 are FIG. 4 is a front view schematically showing only the essential parts of yet another practical example of the present invention. FIG. 4 is a front view schematically showing only the essential parts of another practical example of the present invention. 0...Color original, 1...Original placement glass, 2...
Illumination wrap, 3, 5, 14, 15, 20.21... Dichroic mirror, 4, 6, 7, 16, 17, 18° 22.23... Plane mirror, 24.25... Semi-transparent mirror, 2
6,27゜28...Filter, 8.9.10 ・
...Imaging lens, 11, 12. 13 ・・・Solid image Seven sir man 1 diagram p Qi 4 diagram

Claims (1)

[Claims] An apparatus for reading a color original by separating it into three primary colors α, β, and γ, comprising: illumination scanning means for illuminating and scanning the original; six solid-state image sensors; Six imaging lenses are provided for each of the image sensors and form the image of the reading section onto the light receiving area of each corresponding solid-state image sensor, and the light from the color original is divided into six primary colors α. , β, and γ, wherein the color separation means is disposed on the object side of the six imaging lenses.