JPH056966U - Image reader - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain an image reading device having a high reading speed, which can simultaneously read an image of a color original which is separated according to the three primary colors of light. In an image reading apparatus 10 for illuminating a document P with illuminating light and detecting the reflected light with a sensor to read image information on the document, a part of the light reflected on the document surface is reflected to produce a first image. The first half mirror 15 that guides the light to the first sensor unit 18 via the color filter 18b, and a part of the light transmitted through the first half mirror is reflected, and the reflected light transmits a color different from that of the first color filter. The third sensor unit 19 is guided to the second sensor unit 19 via the second color filter 19b, and the third sensor unit is transmitted via the third color filter 20b that transmits the transmitted light in a color different from those of the first and second color filters. And a second half mirror 16 which leads to 20.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention is incorporated into a color scanner or the like to read an image of a color original document. Image reading device, especially for color images separated into three primary colors and read at the same time. The present invention relates to an image reading device which can be taken.

[0002]

[Prior art]

  Conventionally, in a color image reading device such as a color scanner, an image on the original surface is printed. When reading the image, an image reading device as shown in FIG. 2 was used.   In the figure, an image reading apparatus 1 is a document that is relatively moved in one direction X. The line P is irradiated with linear illumination light in a direction orthogonal to the moving direction of the document P. Light source 2 and the light from this light source 2 is reflected by the document surface (the lower surface of document P in the figure) The lens array 3 that collects the reflected light that has been collected, and the lens array 3 that collects the reflected light. The light receiving device 4 receives light.

[0003]   When the color document P is read by the image reading device 1, the light source 2 is used. For example, the line-shaped illuminating light is time-divided into red, blue, and green, and is radiated specifically and reflected by the document surface. Do not scan the emitted light with the light receiving device 4 which is a monochrome sensor such as a CCD. However, the reading operation is performed in accordance with the movement of the original. By repeating the above steps, the color image on the document surface is read.

[0004]

[Problems to be solved by the device]

  By the way, the light source 2 of the image reading apparatus 1 is sequentially controlled by appropriate switching control. Illumination light corresponding to each of the three primary colors of light is emitted to a predetermined position on the document surface. ing. Therefore, the light receiving device 4 needs to reflect the light reflected from the document surface for each color. Since the time-divisional reading is performed for each element, the image reading efficiency is extremely poor. There was a problem saying.   In addition, the light source 2 that emits illumination light including three wavelengths is adopted, and the light receiving device 4 is provided with the original light. When the reflected light from the manuscript enters, three band-pass filters are used to separate it. There is also a method to use. However, even in this case, there are three types for separating each of the three primary colors. This band-pass filter is used in a time-sharing manner by appropriate switching control. Therefore, the light receiving device 4 sequentially decomposes the reflected light from the document surface by each filter. Each color element will be read separately, which will speed up the image reading. It does not happen.   The present invention has been devised in view of the above problems, and it is divided according to the three primary colors of light. Scanning speed that allows you to simultaneously read the image of the uncovered color original It is an object of the present invention to provide a fast image reading device.

[0005]

[Means for Solving the Problems]

  In order to solve the above problem, the image reading device according to the present invention is reflected by the original surface. Part of the reflected light is guided to the first sensor section via the first color filter. The first half mirror and a part of the light transmitted through the first half mirror are reflected. A second color filter that transmits the reflected light of a color different from that of the first color filter. It is guided to the second sensor section through the same and the transmitted light is different from that of the first and second color filters. Second half-mimic color that is guided to the third sensor unit via the third color filter that transmits the It is characterized by being composed with Ra.

[0006]

[Action]

  According to the above configuration, the first half mirror causes the reflected light from the original surface to be reflected by the first sensor unit. Light transmitted to the first half mirror and transmitted to the second half mirror. Light reflected by the second sensor section and transmitted through the second half mirror It is divided into three types of light that are incident on the sensor unit at the same time.   Then, the light divided into three as described above by each of the first and second half mirrors. Through the color filters formed to transmit different colors, respectively. It will be guided to each of the third to third sensor sections at the same time. Therefore, these first Once the light corresponding to the three primary colors of light is read by the third to third sensor, once The color image can be read by the reading operation of.

[0007]

【Example】

  Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG.   FIG. 1 is a schematic diagram showing an image reading apparatus 10 according to this embodiment.   In the figure, the image reading device 10 is a document that is relatively moved in one direction. A light source 12 for irradiating P with illumination light in a direction orthogonal to the moving direction of the original P. And a lens array that collects the light reflected from the document surface by the light from the light source 12. B and the light collected by the lens array 13 into three light receiving portions 18, 19 , 20 to distribute the first half mirror 15 and the second half mirror And a half mirror 16.

[0008]   The light source 12 is, for example, a fluorescent tube extending in a direction perpendicular to the paper surface or a light emitting die. An LED array or the like in which the odes are arranged side by side in a row is preferably used, and the direction of movement of the document P is Illumination light is emitted along the orthogonal scanning direction. In particular, this embodiment In that case, one light source that emits light containing three wavelengths corresponding to the three primary colors of light is used. Then, a color image can be read as will be described later.   The lens array 13 changes the refractive index distribution along the direction perpendicular to the paper surface, for example. A large number of lenses are integrally arranged in a row. Len arranged in this row As a result, the line-shaped illumination light emitted from the light source 12 to the original P is Reflected light reflected on the lower surface of the original P in the drawing is used as a first half mirror described later. It is designed to focus on 15.

[0009]   The first half mirror 15 is adjusted in a predetermined angle and the lens array 13 is adjusted. A part of the light condensed by the light is reflected, and the reflected light is reflected by the first sensor unit 18 described later. And the light transmitted through the first half mirror 15 is guided to the second half mirror. It is designed to be incident on -16.   The light transmitted through the first half mirror is incident on the second half mirror 16. And this light is reflected by the second half mirror 16 to the second sensor section 19. The reflected light that reaches the third sensor unit 20 and the transmitted light that reaches the third sensor unit 20 through the angle Is being adjusted.

[0010]   The first sensor unit 18, the second sensor unit 19, and the third sensor unit 20 are The examples have a common configuration.   Therefore, this will be described for the first sensor unit. This first sensor unit 18 For example, a monochrome type light receiving element 18a including a CCD and the light receiving element 18a And a first band-pass filter 18b disposed on the front surface of the. By this The reflected light reflected by the half mirror 15 passes through the bandpass filter 18b. In this case, colors other than red, for example, are not transmitted. The child 18a has a red color corresponding to the three primary colors of light among the reflected light forming the color image. Only the prime is detected. Furthermore, the bandpass filter 18b On the front side, a neutral density filter or other neutral density filter is used for the reasons described below. 18c is provided.   Similarly, the second light receiving unit 19 includes a light receiving element 19a and a second color filter 19b. The third light receiving unit 20 is composed of a light receiving element 20a and a third color filter 20b. Has been. The first, second and third color filters 18b, 19b and 20b are The transmitted colors are different. For example, the first color filter 18b outputs red. The second color filter 19b transmits green and the third color filter 20b transmits blue. It has become so.

[0011]   The image reading apparatus 10 according to the present embodiment is configured as described above, and its operation will be described next. State.   The movement of the original P moving from the light source 12 in the X direction with respect to the lower surface in the drawing. When the linear illumination light is emitted along the direction orthogonal to the direction, this light is emitted from the original P. Is reflected by the lower surface of the first half mirror 1 in the lens array 13. It is focused on 5.   The light reflected by the first half mirror 15 is guided to the first sensor unit 18, where Instead, it is dimmed by the dimming filter 18c so that its light amount is halved, for example. Next, when passing through the bandpass filter 18b, for example, only the red component is transmitted. And is incident on the light receiving element 18a. The sticking is detected and a predetermined detection signal is output.   The light transmitted through the first half mirror 15 is then transmitted to the second half mirror 16. The reflected light that enters and is reflected by the half mirror 16 enters the second sensor unit 19. Shoot. At this time, a neutral density filter is not used for the sensor unit 19. This is The amount of light entering the sensor unit 19 is ¼ of the light entering the half mirror 15. Yes, as a result of being dimmed by the neutral density filter 18c in the sensor unit 18, the light receiving element This is because the amount of light incident on 18a is the same. Since the sensitivities of the sensors can be made uniform, it becomes easy to improve the detection accuracy. Therefore The light reflected by the second half mirror 16 is filtered by the bandpass filter 19b. For example, only the blue component is transmitted and enters the second light receiving element 19a, The element 19a detects the blue component of the color image and outputs a predetermined detection signal.   Further, the light transmitted through the half mirror 16 is incident on the sensor unit 20, and the bandpass When passing through the filter 20b, for example, only the green component becomes, which is the light receiving element. Since it is incident on 20a, the light receiving element 20a detects the green component of the color image, Outputs a constant detection signal. In addition, the amount of light incident on the light receiving element 20a depends on other light receiving elements. It goes without saying that it is the same as the children 18a, 19a.

[0012]   Thus, each of the sensor units 18, 19 and 20 responds to the three primary colors of light of the color image. Each component will be detected simultaneously, and the above detection operation will be repeated along the scanning direction. By processing the signal generated by each sensor unit by an appropriate processing circuit, The color image on the lower surface of the document P can be read.

[0013]

[Effect of device]

  As described above, according to the present invention, a color image on the document surface is more easily displayed than in the past. Excellent image reading device that can read efficiently at extremely fast speed Can be provided.

[Brief description of drawings]

FIG. 1 is a schematic view showing an entire image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic view showing an example of a conventional image reading device.

[Explanation of symbols]

10 image reading device, 12 light source, 13
Lens array, 15 first half mirror,
16 2nd half mirror, 18 1st sensor part, 19 2nd sensor part, 20 3rd
Sensor unit, 18b first color filter, 19b
Second color filter, 20b Third color filter.

Claims (2)

[Scope of utility model registration request] 1. A document moving relatively in one direction is irradiated with illumination light in a direction orthogonal to the moving direction of the document, and the light reflected from the document surface is detected by a sensor to detect the document. In an image reading device adapted to read image information, a first half mirror that reflects a part of the light reflected on the document surface and guides it to a first sensor unit via a first color filter; A part of the light transmitted through the first half mirror is reflected, and the reflected light is guided to the second sensor unit via the second color filter which transmits a color different from the first color filter, and
An image reading apparatus comprising: a second half mirror that guides transmitted light to a third sensor unit via a third color filter that transmits a color different from the first and second color filters. 2. The image reading apparatus according to claim 1, further comprising a neutral density filter interposed between the first half mirror and the first color filter.