JPH029262A - Color image sensor - Google Patents

Abstract

PURPOSE:To obtain a large color signal output with a single light source and a single photoelectric conversion element array by using a color filter member able to be driven, arranging the light source in the inside of the member and arranging the light sensor member to the outside. CONSTITUTION:A color filter member 3 is used as color filters (3-1, 3-2, 3-3) made of colored slit glass or plastic in red, green blue and the filters are arranged in parallel alternately for each color, fixed cylindrically to a stationary ring 8 and the inside has a light source 2 and the photosensor member 1 having the photoelectric conversion element array of the same width as the original is arranged at the outside of the said color filter member in parallel with the center axis of the color filter member.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color image sensor for reading color originals in facsimiles, digital copying machines, etc.

[Prior Art] A color image sensor used in facsimile machines, digital copying machines, etc. is basically a combination of a color separation mechanism with a normal image sensor mainly consisting of a light source and a photoelectric conversion element array.

Regarding the color separation mechanism in conventional color image sensors, for example, Japanese Patent Laid-Open No. 58-212255 describes the color separation mechanism for red, green,
Color separation is performed by switching the illumination light sources for each color of blue, but this method requires a plurality of light sources, which increases the size of the device and increases the cost. Furthermore, JP-A-60-123059 proposes a device in which color filters for each color are provided on an optical sensor member having a row of photoelectric conversion elements, but in the case of this device, a row of photoelectric conversion elements is required for each color filter. Therefore, manufacturing becomes extremely complicated. Furthermore, in JP-A No. 60-74569, three types of photosensor members each have a color separation function using an a-Si photosensitive material, but since these photosensor members are laminated, the direction of incidence of light is On the other hand, the lower the layer, the lower the color sensitivity, and the lower the light transmittance when the photosensitive material is used as a color filter (dye).

(compared to pigments, etc.), and therefore has the disadvantage that the color signal output is also small.

[Problems to be Solved by the Invention] The purpose of the present invention is to eliminate all of the above-mentioned drawbacks in the prior art, to easily manufacture a single light source without increasing the number of photoelectric conversion element arrays, and to provide a large It provides a simple, compact, and economical color image sensor that can obtain a color-accurate output.

[Structure and operation of the invention] The color image sensor of the present invention has a light source inside a cylindrical color filter member having red, green, and blue band-like filters arranged parallel to the central axis and alternating with each color on the surface. At the same time, an optical sensor member having a photoelectric conversion element array having the same width as the original is arranged outside the color filter member so that the photoelectric conversion element array is parallel to the central axis of the color filter member. This is a characteristic feature.

To explain the present invention with reference to the drawings, FIGS. 1(a) and (
1)) are schematic cross-sectional rT+i diagrams of examples of the color image sensor of the present invention, in which 1M(a) shows the contact type, and FIG. 1(1)) shows the complete contact type, and 7. The main difference between the close-contact type and the fully dense n-type is the presence or absence of an equal-magnification coupling element; the close-contact type has an equal-magnification coupling element 7, whereas the fully close-contact type does not have such an element. do not have. close contact type,
In any of the fully contact type color image sensors, the light from the light source 2 is resolved by the force of 1-7 rotations in synchronization with the scanning speed. After that, it is positioned on the platen 0-5-4 and emitted onto the image surface of the original E'i, and the reflected light (-7) is converted into an electrical signal by the optical sensor section 1 having a photoelectric conversion element array. Converted. Note that 6 in Figure 1(a)
is a document holding member for maintaining a constant distance between the object (here, the document 5) determined by the same-magnification imaging element 7 and the image (here, the optical sensor 6-1 member 1); It is contact glass.

In FIG. 1(b), such a contact glass is unnecessary because the optical sensor member 1 can be used instead.

In the color image sensor as described above, the optical sensor member 1 includes, for example, a transparent substrate 1--3 and a photoelectric conversion element array 1.
-2 and a transparent protective layer 1-1. Note that the constituent materials of the substrate, the photoelectric conversion element array, and the transparent protective layer may be the same as conventional materials, but the photoelectric conversion element array preferably has a substantially uniform intensity distribution in the visible wavelength range.

Like this] Amorphous Si is used as a photoelectric conversion element array.
Examples include photodiodes and photoconductor cells made of photoelectric materials such as , CdS, and Se.

Next, the color filter member of the present invention will be explained.

Specific examples of this color filter member are shown in FIGS.
As shown in c), the color filter member 3 in FIG. 2(a) is a color filter (3-1, 3-2, 3-3) made of glass or plastic strips colored red, green, and blue, respectively.
The color filter member 3 of FIG. 2(b) is arranged alternately in parallel for each color and fixed in a cylindrical shape with a fixing ring 8. The color filter member 3 of FIG. The band-shaped filters (3-1, 3-2, 3-3) of red, green, and blue colors are arranged alternately, 1-1 for each color, on the central axis of the cylinder and the -V row. Ink of each color is applied using the screen printing method, and the color filter member 3 in Figure 2 ((7) is a strip-shaped glass plate or stick film colored red, green, and blue respectively. Filter (3-1, 3-2,
3-3), and these were pasted on the surface of a transparent cylinder 9 in such a way that they were arranged parallel to the central axis of the cylinder and alternately for each color (however, here, there was a slight gap between each filter). be.

The principle of forming color signals by the color filter member as described above is as follows. That is, in the third step 1, when the image surface of the original 5 is first irradiated with light that has passed through, for example, a red filter 3-1, a red image signal is obtained, [FIG. 3(a)],
Next, by rotating the color filter member 3, the light that has passed through the green filter 3-2 and the blue filter 3-2 and the light that has passed through the Jf filter 3-3 are irradiated below the light source 2.
A recorded image signal [Fig. 3(b)] and a blue image signal [Fig. 3(C)] are obtained. In this case, the original may be kept still until the three color signals are obtained, but it may be moved if the resolution is not so required. However, the rotation speed of the color filter unit 3 should be Light of sensor member 1'
It is necessary to synchronize with the main speed of the city conversion element array.

The light sources 2, 1 and 2 may be the same as conventional ones, but preferably have almost uniform intensity in the visible wavelength range.

Examples of such light sources include white fluorescent lamps and halogen lamps.

[Operations and Effects of the Invention] According to the present invention, a rotatable color filter member as shown below is used, and a light source is disposed inside the member and a light sensor member is disposed outside to read a color image. Since the mechanism is configured, a large color signal output can be obtained with a simple light source and a single photoelectric conversion element array, and it is also easy to manufacture, thus creating a simple, compact, and economical color image sensor. − can be provided.

44 Brief description of the drawings FIGS. 1(a) and (b) are schematic sectional views of an example of the color image sensor of the present invention, and FIGS. 2(a), (b), and (c) are respectively schematic sectional views of an example of the color image sensor of the present invention. Oblique view of an example of a color filter member used in a color image sensor, FIG. 3(a)
, (b) and (c) are explanatory diagrams of the principle of forming color signals by the color filter member.

1... Optical sensor member having a photoelectric conversion element array 2... Light source member 5 Original 7 Equal-magnification coupling element 8 Fixing ring 9 Transparent 11) Fabric [3 Figure 11-2 = -- Quality / \ (b ) 12221/'1 (C) 1222L 72-- Hano-/3-2no

Claims (1)

[Claims] 1. A light source is placed inside a cylindrical color filter member that has red, green, and blue band filters arranged parallel to the central axis and alternately for each color on the surface, and a light source is placed outside the color filter member that is identical to the original. A color image sensor comprising a photosensor member having an array of photoelectric conversion elements with a width of 100 mm, and arranged so that the array of photoelectric conversion elements is parallel to a central axis of a color filter member.