JP3120433B2 - Reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] A reading device that diffracts reflected light from a document by a hologram element in different directions according to the wavelength range and receives the reflected light at corresponding light receiving elements has a simple mechanism and is small and light. And cost reduction,
In addition, the object of the present invention is to provide a reading device capable of reading at high speed, provided on the optical path of the reflected light of the light illuminating the original from the light source, and diffracting the emitted light in different directions according to the wavelength range of the reflected light. One hologram element and a plurality of light receiving elements that are respectively arranged on optical paths through which light diffracted in different directions by the hologram element passes, receive the diffracted light, and convert the light into an electric signal, are provided by the light receiving element. It is configured to read an image of a document based on the converted electric signal.

[Industrial applications]

The present invention relates to a reading optical system of a color reading apparatus, and more particularly to a reading apparatus that diffracts reflected light from a document into different directions according to a wavelength range by a hologram element and receives the reflected light at corresponding light receiving elements. It is.

2. Description of the Related Art Recently, a color reading device has been used as an image input device to a facsimile or a computer, and a device that reads three colors of red, green, and blue with a light receiving sensor has been developed and put into practical use.
In this apparatus, since the three colors of red, green, and blue are sequentially switched to receive light, the mechanism is complicated and expensive, and it takes a long time to read. Therefore, it is desired to reduce the cost and speed up the reading.

[Conventional technology]

The filter switching type color reading apparatus will be described with reference to FIGS. 6 and 7. FIG. FIG. 6 is a perspective view showing an outline of a color reading apparatus to which the present invention is applied, and FIG. 7 is an explanatory view of a conventional example.

As shown in FIG. 6, the original 1a is set with the read image facing a glass plate (not shown), and the original 1a is placed through the glass plate.
A reading line 3 on 1a is illuminated by a light source 2a composed of a fluorescent lamp, and an image on this line is read. The reflected light from the reading line 3 is imaged by the lens 4 on the light receiving sensor 5a composed of a charge-coupled device (CCD).

To perform color reading, three filters 6a to 6c of red (R), green (G), and blue (B) are provided between the lens 4 and the light receiving sensor 5a. The filters 6a to 6c are held by linear motors 7a to 7c, respectively.
It can be moved to a position that blocks the optical path to

With such a configuration, the color reading operation will now be described with reference to FIGS. 7 (a) to 7 (c).

First, when reading the R component of the color image on the reading line 3, as shown in FIG.
The filter 6a of R out of .about.6c is driven into the optical path by driving the linear motor 7a. The other two filters 6b and 6c are held at positions that do not block the optical path.

As a result, of the reflected light from the reading line 3, red light can reach the light receiving sensor 5a, and the R component of the image is read.

When reading the G and B components of the image, as shown in FIGS. 7 (b) and (c), the G filter 6b and the B filter 6c are inserted into the optical path and read. When reading of R, G, B of one line is completed, the original 1a is transported by a predetermined length in the direction of arrow A in FIG. 6, and reading of the next line is performed.

Small and lightweight filters 6a to 6c and high-speed linear motor
By combining the filters 7a to 7c, the filters 6a to 6c are switched in the same time as the reading time of the light receiving sensor 5a, and color reading is realized.

When the filters 6a to 6c are removed from the reading optical path,
Black and white reading can be performed, and a color and black and white reading device can be shared by one device.

In the above example, the insertion position of the filters 6a to 6c is set between the lens 4 and the light receiving sensor 5a. However, there is a method of inserting between the original 1a and the lens 4, and three separate filters 6a to 6c are used. However, as shown in the side view of FIG. 8A and the perspective view of the filter of FIG.
There is also a method in which a single plate is reciprocated up and down in the optical path.

[Problems to be solved by the invention]

According to the above conventional method, when reading the read line, R,
Since three filters G and B are sequentially inserted into the optical path and each color component is received by the light receiving sensor to read an image of one line, a driving means for moving the filters is required. The mechanism is complicated, which makes the device large and heavy. In addition, the failure rate is high because there are many moving mechanisms.

In the case of color printing, approximately three times as long reading time is required.

Therefore, there is a problem that the cost of the apparatus increases and the use efficiency is poor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a reading device which has a simple mechanism, can be reduced in size and weight, and can improve cost, and can read at high speed.

[Means for solving the problem]

 FIG. 1 is a diagram illustrating the principle of the present invention.

In the drawing, reference numeral 1 denotes a document, 2 denotes a light source, 9 denotes at least one light source provided on the optical path of the reflected light of the light illuminating the document 1 from the light source 2 and diffracting the reflected light in different directions according to the wavelength range of the reflected light. Hologram elements.
That is, one for a plurality of wavelength regions may be used, or a plurality for a single wavelength region may be used.

Reference numerals 5 denote a plurality of light receiving elements which are arranged on optical paths through which light diffracted in different directions by the hologram element 9 passes, and which receives the diffracted light and converts it into an electric signal.

Therefore, the light diffracted by the hologram element 9 is received by the light receiving element 5, converted into an electric signal, and the image of the document 1 is read.

[Action]

The light in at least one wavelength range of the reflected light of the light illuminating the original 1 from the light source 2 is diffracted in different directions by the hologram element 9 according to the wavelength range, and the diffracted light is respectively received by the corresponding number of light receiving elements 5. Receives light and converts it to an electrical signal to copy the original
Image can be read at the same time, different wavelength regions of reflected light can be read at the same time, and the reading time can be reduced with a simple mechanism, and the apparatus can be reduced in size and weight, cost can be improved, and High-speed reading becomes possible.

〔Example〕

2 and 3 show one embodiment of the present invention. The same reference numerals indicate the same objects throughout the drawings.

In FIG. 2, those having the same names as those in FIG.
The light receiving sensors 5b to 5d and the hologram 9a in the figure correspond to the light receiving element 5 and the hologram element 9 in FIG. 1, respectively.

The present invention is a color reading apparatus using a hologram that diffracts in a plurality of directions corresponding to different wavelength ranges of light, and the hologram will be described below.

FIG. 3A shows the spectral characteristics of the hologram element when white light is incident at an irradiation angle. As shown in the figure,
The hologram element has a characteristic that, out of incident light, only a wavelength region (λ ₀ ) designed in advance is reflected in a specific direction, and light in other wavelength regions is transmitted. This diffraction wavelength range can be freely set, and the incident angle and the diffraction angle can also be freely set.

Further, as shown in FIG. 3 (b), a function having a plurality of diffraction wavelengths (λ _{1 to} λ ₄ ) in one hologram material can be realized.

Also, a function of condensing light for each diffraction wavelength range can be provided.

In the case of a hologram element for a single wavelength range as shown in FIG. 3A, layers having different wavelength ranges are laminated, and in the case of a hologram element for a plurality of wavelength ranges as shown in FIG. 3B. Is installed alone in the optical path.

As a result, the hologram element has the R, G, B
Have the characteristics corresponding to the filters of each color.

FIG. 2 is a side view of a main part of the color reading apparatus to which the present invention is applied. As shown in FIG. 2, a document 1a is set on a glass plate 8, and a light source is placed in a light source unit 20 below the glass plate 8.
2a is arranged to illuminate the reading line 3 on the original 1a.

The hologram 9a is placed on the optical path of the reflected light of the illuminated original 1a.
Are provided at a predetermined angle (for example, 45 degrees).

The hologram 9a has a function of diffracting light in different directions according to a plurality of wavelength ranges of the reflected light.

That is, the light is diffracted in three directions corresponding to the wavelength ranges of the three colors R, G, and B.

Lenses 4a to 4c and light receiving sensors 5b to 5d are provided on the respective optical paths of the light in the three color wavelength ranges of R, G, and B diffracted by the hologram 9a.

The light receiving sensors 5b to 5d have the same function as the light receiving sensor 5a described in the conventional example.

With this configuration and function, the light reflected by illuminating one line on the original 1a from the light source 2a
Diffracted by 9a, light in the three color ranges of R, G, B is condensed by the lenses 4a to 4c, respectively, and at the same time
Image on ~ 5d.

Therefore, the light receiving sensors 5b to 5d are sequentially
To 6c, it is possible to simultaneously receive the same light as when the light is received by the light receiving sensor 5a.
Color reading can be performed in about 3 short times. And filter 6
Since the driving means for moving a to 6c is omitted, the mechanism is simple, the size and weight can be reduced, and the cost can be improved.

In addition, the number of read sheets until the life of the fluorescent lamp of the light source 2a can be increased.

FIG. 4 and FIG. 5 show different embodiments (1) and (2). A different embodiment (1) of FIG.
In a method in which the hologram 9b is provided with a condensing function and the light of each wavelength region diffracted by the hologram 9b is imaged on the light receiving sensors 5b to 5d, the lenses 4a to 4c described in the embodiment are omitted.

A different embodiment (2) of FIG. 5 is provided with holograms 9c and 9d, and the hologram 9c is set to have a function of reflecting light in the wavelength range of R color and transmitting light of other colors. The light in the wavelength range of G color is reflected from the transmitted light, and is reflected in another color, that is, B light.
Each lens 4a is set to transmit light in the color wavelength range.
This is a method of condensing light at で 4c and forming an image on the light receiving sensors 5b to 5d.

 In each case, the same effects as in the above embodiment can be obtained.

〔The invention's effect〕

As described above, according to the present invention, light can be diffracted in different directions by at least one hologram according to the wavelength range of the light reflected from the document, and can be received simultaneously by the light receiving elements on the respective optical paths. There is no need for a driving means for moving the filter as in the conventional method, and the mechanism is simplified, so that the device is small,
Weight is also reduced. Also, since there is no moving mechanism, there is no failure.

In the case of color printing, high-speed reading of approximately three times that of the conventional method can be performed.

Therefore, there is an effect that the cost of the apparatus is improved and the use efficiency is improved.

[Brief description of the drawings]

1 is a principle view of the present invention, FIG. 2 is a side view showing an embodiment of the present invention, FIG. 3 is an explanatory view of a hologram, FIG. 4 is a side view showing a different embodiment (1), FIG. FIG. 6 is a side view showing a different embodiment (2), FIG. 6 is a perspective view showing an outline of a color reading apparatus to which the present invention is applied, FIG. 7 is an explanatory view of a conventional example, and FIG. FIG. In the figure, 1, 1a denotes an original, 2, 2a denotes a light source, 5 denotes a light receiving element, 5a to 5d denote light receiving sensors, 9 denotes a hologram element, and 9a to 9c denotes a hologram.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-179269 (JP, A) JP-A-61-269570 (JP, A) JP-A-59-92667 (JP, A) JP-A-61-26967 122943 (JP, A) JP-A-3-135266 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/028 H04N 1/04

Claims (1)

(57) [Claims] At least one hologram provided on an optical path of reflected light of light illuminating a document (1) from a light source (2) and diffracting the reflected light in different directions according to the wavelength range of the reflected light. An element (9), and a plurality of light receiving elements (5) arranged on an optical path through which light diffracted in different directions by the hologram element (9) passes to receive the diffracted light and convert it into an electric signal. ), And reads an image of the document (1) based on the electric signal converted by the light receiving element (5).