JPS61195066A - Color original reading device - Google Patents

Abstract

PURPOSE:To enable a color separation with a requested spectral characteristics by providing a color separation means that has a plural color separation element with different spectral characteristics against one color separation at an intermediate light path between an original face and a line sensor with reading width of the line sensor. CONSTITUTION:By moving a color original 1, the reflecting light of the original 1 illuminated from a light source 2 is image-formed at, through a mirror 3 and a lens 4, the line sensor that is constituted as a CCD5. Preceding an image formation to the CCD5, it is split by a color separation means 6. In a means 6, a color separation element that is constituted as a plural color separation filter 7 in a sector form, a separation member 9 that arranges a plural shading plate 8 in the form of a disc and a step motor 10 are provided. As a filter 7, for example, red filters R1-R3, blue filters B1-B4 and green filters G1 and G2 are used and each different spectral characteristic even in a same color can be selected. Thus, the color separation with the requested spectral characteristics can be obtained.

Description

[Detailed description of the invention] Technique! The present invention relates to a color document reading device that uses a line sensor to read reflected light from a color document illuminated by a light source.

BACKGROUND OF THE INVENTION Color document reading devices of the above type are well known and are used in color facsimile machines, digital color copying machines, digital color manual machines, and the like.

This type of conventional reading device uses, for example, three red, green, and blue filters or three dichroic mirrors when performing color separation. That is, one color separation element was used for separation in one color.

However, in the above document reading apparatus, the spectral characteristics of the color separation elements used are often not the desired spectral characteristics. That is, in one color separation element, the spectral characteristics often deviate from the most preferable spectral characteristics for color separation, or the spectral characteristics differ from the desired spectral characteristics. For this reason, there was a problem that the desired color reproduction could not be obtained6.The present invention eliminates the above-mentioned conventional problems and provides a color document reading device that can easily obtain color separation with desired spectral characteristics. It is intended to.

To achieve this objective, the present invention provides a color separation means along the reading width of the licensor in the optical path between the document surface and the licensor, and the color separation means determines the spectral characteristics for separation of one color. This was achieved by including a plurality of color separation elements with different color separation elements.

Lost in the sky Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a color original, and 2 a light source such as a fluorescent lamp. In this embodiment, when the original is moved and reading scanning is started, the color original 1 is illuminated by the illumination of the light source 2. The reflected light is imaged through a mirror 3° lens 4 on the light receiving surface of a line sensor configured as a CCD 5.

Prior to image formation on the CCD 5, color separation is performed by a one-color separation means 6.

As shown in FIGS. 1 and 2, the color separation means 6 is formed by arranging color separation elements configured as a plurality of fan-shaped color separation filters 7 and a plurality of light shielding plates 8 in a disc shape. It has a disassembly member 9 and a drive device configured as a step motor 10 for rotating the disassembly member. As shown in FIG. 3, the color separation filter 7 includes, in this example, three filters R1, R2, R3, four blue filters Bl v B2 v 83 v B4, and two green filters 〇11G2. It is equipped with In this case, the color separation filters 7 are arranged in groups of the same color, and the light shielding plate 8 is arranged between the filters of different colors. Further, as the color separation filters 7 for each color, filters having the same color but different spectral characteristics are appropriately selected and used, as shown in FIG. 4, for example. Note that the imaging lens 4
As shown in FIG. 5, when viewed from the front of the disassembled member 9, the light emitted from the disassembled member 9 passes along a straight line 1 passing through its center and between the center point and the outer periphery. The light receiving surface 5a of the CCD 5 is arranged on a straight line corresponding to the straight line 1.

The color document reading device configured in this manner can perform color separation with desired spectral characteristics for each color. This will be explained in detail below using an example of color separation using a red filter.

In the case of a red filter, three filters R1゜R2, R
3 is used, and the curves of the respective spectral characteristics shown in FIG. 4 are shown as FR, (f) for convenience of explanation.

Let it be expressed by the formulas FR2(f) and FRs(f). In addition, the outer circumferential lengths of each filter R, R2, and R3 are different,
And because the circumferential speed of the disassembly member 9 is constant.

Each exposure time is t l for R1, t2 for R'2. R
3 and denoted by t3 (see Fig. 3). Therefore, if we express the exposure amount E to ccD5 through the three example filters R, , R2, and R3 using the formula, E = t t IJFRt (f ) + t2 ■ fFR
3! (f)+t3I,/'FRs(f), where: I is the amount of light.

The exposure amount E in this case is the same as that obtained by irradiating the red filter with the spectral characteristics shown in FIG. 6 for a time period t, +t2 +t3. Therefore, the apparent spectral characteristics of the red filter when the red filters R,,R2,R, are each irradiated at a rate of time ``S e i2t j3'' are 61st!I
The spectral characteristics are shown in .

In this way, the spectral characteristics of the red filter are as follows for each filter R
, R2, R3 and their outer circumferential lengths can be changed arbitrarily.

As a result, desired spectral characteristics can be obtained by appropriately selecting the spectral characteristics and outer circumference length of each filter.

In this way, the red filters R, , R2, and R enable preferable color separation similar to the case where color separation is performed using a red filter having desired spectral characteristics.

Also, blue filter 81e B2 y B3 t B4
The same applies to the green filters G1 and G2, and the same color separation as when color separation is performed using filters having desired spectral characteristics is possible. In this embodiment, there are three filters for each color, three for red, four for blue, and two for green, but the number of these filters may be selected as appropriate depending on the spectral characteristics of each filter.

In the color document reading device configured as described above, when reading scanning is started as described above, the color document 1 is color-separated line by line by the color separation means 6, and the color document 1 is color-separated line by line by the color separation means 6.
The image is formed on a. At this time, the disassembly member 9 is connected to the pulse motor 1.
0, it rotates once every time one line is read, and therefore color separation is performed for red, blue, and green according to desired spectral characteristics.

Further, by one rotation of the one-color separation member 9, the CCD 5 is shielded from light every time the color changes by the light-shielding plate 8 provided between each color filter. In this case, as shown in FIG. 5, as the disassembly member 9 moves, the light-shielding plate gradually descends, gradually begins to block light from the light-receiving surface 5a, and eventually completely blocks light. The light-receiving surface 5a is illuminated through the color filter on the rear side.

In this way, if the light shielding plate 8 is provided, two different colors can be displayed on the light receiving surface 5.
This is extremely advantageous in terms of reading accuracy, etc., since there is no overlap in a.

7 and 8 show another embodiment of the invention, in which the color separation means 16 has a cylindrical separation member 19. In FIG. The separation member 19 is configured by arranging a plurality of color separation filters 17 and a plurality of light shielding plates 18 on its side.

That is, each filter 17 and light shielding plate 18 are formed in a curved band shape with a predetermined curvature, and these are arranged one after another.
A disassembly member 19 is configured. Disassembly member 1 with this structure
9 is provided with support members (not shown) on both sides thereof, and is operated by a step motor (not shown) via the support members.
Each time one line is read, it is rotated one rotation in the direction of the arrow. Furthermore, a CCD 1 5 is arranged inside the disassembly member 19.

Also in the color separation means 16 having such a configuration, the red filters R, , R2, and R3 each have different spectral characteristics.

Blue filter Bl + B2 e B3 y B4 y
By providing the green fields 01 and G2 and arranging the light shielding plate 18 between each color, the same effect as in the previous embodiment can be obtained.

FIG. 9 shows still another embodiment of the present invention, in which a dichroic mirror 2 is used as a color separation element of the one-color separation means 26.
A wavelength selective mirror configured as 7 is used. In this case, the disassembly member 29 is formed into a polygonal column shape by arranging a plurality of dichroic mirrors 27 and a plurality of light shielding plates 28 side by side. That is, the mirror 27 and the light shielding plate 28 are provided on a plane parallel to the axis of the prism. In this case, the disassembly member 29 is rotated in an arrow direction by a step motor (not shown) with approximately the center as a fulcrum, and an image is formed on the CCD 25 via each mirror 27 at this time. In this example as well, the spectral characteristics of each dichroic mirror 27 are different, and there are mirrors R1, R2, and R3 that select wavelengths in the red region, and mirrors Bl + B2 + B3 * B that select wavelengths in the blue region.
4 and a mirror Gl for selecting the wavelength in the green region, G2.
A light shielding plate 28 is provided between the mirrors of each color.

In the color document reading device configured as described above, the decomposing means 29 rotates once every time one line is read. In this case, the disassembly member 29
For example, the disassembling member 29 may be made into a regular polygonal prism, and the disassembling member 29 may be intermittently fed so that each mirror stops at a position where the light is irradiated onto the CCD 25, or it may be continuously rotated.

According to this configuration, the spectral characteristics of the dichroic mirrors for each color can be synthesized, and the same effect as in the embodiment described above can be obtained. Moreover, by using a dichroic mirror, a decrease in the amount of light can be suppressed.

FIG. 10 shows yet another embodiment of the present invention, in which the color separation means 36 is provided in front of the imaging lens 34. Further, in this example, two dichroic mirrors 37 are provided to select the wavelength of each color region.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways.

For example, the color separation means may be one that separates one color as shown in FIG. 11, and in this case, a dichroic mirror 47 used as a color separation element is formed in the shape of a triangular prism.

Further, the triangular prism disassembled member of the dichroic mirror 57 may be formed hollow as shown in FIG.

Effects The color document reading device according to the present invention is configured as described above, and it is possible to synthesize spectral characteristics, so that color separation can be performed with characteristics that approximate the target spectral characteristics.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing one embodiment of the present invention, and FIG. 2 is a schematic diagram showing an embodiment of the present invention.
FIG. 3 is a front explanatory view showing the arrangement of the separation members; FIG. 4 is a graph showing the spectral characteristics of each filter; FIG. 5 is a partially enlarged front view of the separation members; 6th
The figures are graphs showing the synthesized spectral characteristics, Figures 7 and 8.
The figures are a perspective view and a side explanatory view showing another embodiment of the present invention,
FIGS. 9 to 12 are explanatory views showing different embodiments of the present invention. 1... Color original 5... CCD 6, 16, 26, 36... Color separation means 7.17...
・Filter 27. 37, 47, 57... Dichroic mirror Figure 1 Figure 4 Figure 4 -! %(mm)-m- Soto艮(mm)-1- 7th medical figure 10

Claims (4)

[Claims] (1) In a color document reading device that uses a line sensor to read reflected light from a color document illuminated by a light source, color separation means is provided along the reading width of the line sensor in the optical path between the document surface and the licensor. . A color original reading device, wherein the color separation means includes a plurality of color separation elements having different spectral characteristics for separating one color. (2) The color document reading device according to claim 1, wherein the color separation means includes a plurality of color separation filters having different spectral characteristics for one color field. (3) The color document reading device according to claim 1, wherein the color separation means includes a plurality of wavelength selective mirrors having different spectral characteristics for separation of one color. (4) The color document reading device according to claim 3, wherein the wavelength selective mirror is provided on a surface parallel to the axis of the polygonal prism.