JPH02101861A - Picture scanner - Google Patents

Abstract

PURPOSE:To obtain uniform picture information with high accuracy by using three semiconductor lasers leading a laser beam of different wavelength and a photosensitive material having an absorbing wavelength area corresponding to the laser beam, irradiating the photosensitive material with the laser beam, and converting its reflected light into a color picture signal by a photoelectric conversion element. CONSTITUTION:The 1st-3rd semiconductor lasers 14a-14c are driven sequentially for each picture element under the drive of a control circuit 12 while a photosensitive material 36 is subject to subscanning carrying in the direction of arrow B. A laser beam L1 from the 1st laser 14a is reflected in a reflection mirror 20 through a collimator lens 16a and a warp correcting lens 18a and reaches a reflection mirror 26 through dichroic mirrors 22a, 22b respectively. The beam from the 2nd and 3rd semiconductor lasers 14b, 14c reach similarly to the mirror 26 and the beam is made incident in a reflection mirror 28 and a polygon mirror 30, pictures 40a, 40b are obtained via an ftheta lens 32 and a cylindrical mirror 34 and the 3rd laser 14c corrects them.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image scanning device, and more particularly, three semiconductor radars each emitting a laser beam of a different wavelength are provided, and a semiconductor laser beam corresponding to the laser beam is provided. By irradiating a photosensitive material containing a color forming material with an absorption wavelength range with the laser light, it is possible to accurately read color image information preliminarily carried on the photosensitive material, and it is small and manufactured with low cost. The present invention relates to an image scanning device that can be used.

[Background of the Invention] For example, in the field of printing plate-making, there is an image scanning recording and reproducing system that electrically processes image information carried on a manuscript and creates a film master for the purpose of streamlining work processes and improving image quality. Widely used.

This image scanning recording/reproducing system basically consists of an image reading section and an image recording section.

That is, in the image reading section, monochrome or color image information carried on a document being conveyed in the sub-scanning direction is converted into an electrical signal by a photoelectric conversion element. Next, the image information photoelectrically converted by the image reading unit is subjected to arithmetic processing such as gradation correction and edge enhancement according to the plate-making conditions in the image recording unit, and then converted to an optical signal such as a laser beam. Recording and reproduction are performed on a record carrier made of a photosensitive material such as film.

In this case, when reading the color image information carried on the document, a CCD (Charge
Conventionally, a device has been used that converts the color image information into an electrical signal by arranging coupled cfvices in the main scanning direction, irradiating the document with light from an illumination lamp, and guiding the reflected light to each CCD. ing.

However, in the conventional technique described above, shading is likely to occur due to uneven illumination of the illumination lamp itself, and shading correction is required. Moreover, in reality, each CC
There are variations in sensitivity for each D, and therefore, correction must be applied to all pixels read by the CCD. Furthermore, in order to read with high resolution, a large number of CC
It has been pointed out that the disadvantage is that it is necessary to arrange D with high precision in the main scanning direction.

Therefore, for color originals, for example, RSG.

An apparatus has been proposed in which color image information is obtained by irradiating gas laser light of the three primary colors of B and introducing reflected light or transmitted light from the color document into a photomultiplier serving as a photoelectric conversion element. However, this type of gas laser is quite large and expensive, and incorporating three gas lasers into the device increases the overall size of the device and increases manufacturing costs. It's exposed.

[Object of the Invention] The present invention has been made to overcome the above-mentioned disadvantages, and focuses on semiconductor lasers that are relatively inexpensive and have high resolution, and has developed three types of semiconductor lasers that each emit laser light of a different wavelength. While equipped with a laser, a photosensitive material containing a coloring material having an absorption wavelength range corresponding to each laser beam is used, and the laser beam is irradiated onto the photosensitive material, which carries color image information in advance, to produce a photomultiplier or the like. The device is configured to read desired color image information by converting it into an electrical signal using a photoelectric conversion element, thereby making it possible to perform highly accurate color image reading work, and making the entire device suitable for miniaturization and low manufacturing costs. An object of the present invention is to provide an image scanning device that makes it possible to perform the following operations.

[Means for Achieving the Object] In order to achieve the above object, the present invention includes a main scanning system that irradiates an image recording carrier with a light beam deflected in the main scanning direction, and a main scanning system that irradiates the image recording carrier with a light beam deflected in the main scanning direction. The main scanning system includes a sub-scanning conveyance system that conveys in a direction substantially perpendicular to the above-mentioned direction, and the main scanning system corresponds to the image recording carrier containing three types of coloring materials each having a different absorption wavelength range, and a laser beam within each absorption wavelength range. It is equipped with first to third semiconductor lasers for emitting light, and while the image recording carrier carrying color image information in advance is conveyed in a sub-scanning direction, the laser beams emitted from the first to third semiconductor lasers are emitted. It is characterized in that it is configured to irradiate in the main scanning direction and photoelectrically convert the light from the image recording carrier using a photoelectric conversion element to obtain desired color image information.

[Embodiments] Next, preferred embodiments of the image scanning device according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates an image scanning device according to this embodiment. The image scanning device 10 includes a control circuit 12
Laser light is driven and controlled by L.

It includes a first semiconductor laser 14a to a third semiconductor laser 14c that output . In this case, the laser beam L
The wavelength of laser beam L2 is 830 n rn, and the wavelength of laser beam L2 is 7
50 nm and the wavelength of laser light is 670 nm
m is selected.

A collimator lens 16a is disposed on the laser beam output side of the first semiconductor laser 14a, and a collimator lens 16a that converts the laser beam into a parallel light beam is arranged. will be provided. On the other hand, the second and third semiconductor lasers 14b
, 14c are each provided with a collimator lens 1 on the light output side.
6b116C is arranged, and the collimator lens 16a
Surface tilt correction lenses 18b and 18c are provided at different intervals from 116b. That is, since the optical path lengths of the laser beam, SL, and beam are different,
This is because it is necessary to adjust the positions of the surface tilt correction lenses 18a to 18c, respectively.

A guichroic mirror 22a is provided on the optical path of the laser beams L2 and L3 passing through the surface tilt correction lenses 18b and 18c,
22b, the reflecting mirror 20 and the gicroic mirrors 22a, 22b have the same inclination angle and guide the respective laser beams L1, L2, and L2 to the same optical path 24. Therefore, the guichroic mirror 22a transmits the laser beam LI and reflects the laser beam L2, while the guichroic mirror 22b functions to transmit the laser beam and L2 and reflect the laser beam L3.

The laser beams that have reached the same optical path 24 in this way, ,L
, and L3 are reflected by reflection mirrors 26 and 28 and then irradiated onto polygon mirror 30. The polygon mirror 30 is rotating in the direction of the arrow, and the laser beams L1, L2 and L3 reflected through the polygon mirror 30
passes through the fθ lens 32 and then passes through the cylindrical mirror 34
, and is main-scanned on the photosensitive material 36 in the direction of arrow A. In this case, the photosensitive material 36 is transported in a sub-scanning direction (arrow B
A condensing bar 38 is provided below the photosensitive material 36 and extending in the main scanning direction.

Photoelectric conversion elements, such as photomultipliers 40a and 40b, are attached to both ends of the light condensing bar 38, and the photomultipliers 4Qa and 40b are connected to the image processing circuit 42.
connected to.

Next, the photosensitive material 36 is provided with color forming materials 1, K2, and 3, each having a different absorption wavelength range. Second
As shown in the figure, the coloring material 1 substantially corresponds to the laser beam L1 derived from the first semiconductor laser 14a, and absorbs wavelengths of 800 to 900 nm. On the other hand, coloring materials 2 and 3 correspond to laser beams, L3, 700 to 800 nm and 500 to 700 nm, respectively, derived from the second and third semiconductor lasers 14b and 114C.
It has the property of absorbing wavelengths of nm.

The image scanning device according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

Here, images 44a and 44b corresponding to a desired color image are recorded on the photosensitive material 36 via an image capturing device (not shown) or the like. Further, an identification pattern, for example, a barcode 46, is formed in advance on the photosensitive material 36, and characteristic data of the photosensitive material 36, whether it is a negative image or a positive image, etc. can be determined via the barcode 46. Identification data is stored.

Then, the photosensitive material 36 is loaded into the image scanning device 10. At this time, the photosensitive material 36 may be loaded into a container such as a cartridge, and a bar code indicating characteristic data of the photosensitive material 36 may be formed on the container. With this, when loading the container into the image scanning device 10,
By reading the barcode through a sensor (not shown) provided in the image scanning device 10, characteristic data of the photosensitive material 36, etc. can be detected in advance.

Next, the photosensitive material 36 is sub-scanned and transported in the direction of arrow B in FIG.
The semiconductor laser 14C is sequentially driven for each pixel. Laser light L+ derived from the first semiconductor laser 14a
is made into a parallel light beam by the collimator lens 16a, passes through the surface tilt correction lens 18a, is reflected by the reflection mirror 22, and is reflected by the respective gicroic mirrors 22a12.
2b and reaches the reflecting mirror 26. The laser beam L+ reflected by the reflecting mirror 26 enters the polygon mirror 30 via the reflecting mirror 28, passes through the fθ lens 32, is reflected by the cylindrical mirror 34, and is reflected by the cylindrical mirror 34, forming the first image 44a formed on the photosensitive material 36. Irradiates one pixel.

On the other hand, the laser beam L2 emitted from the second semiconductor laser 14b similarly passes through the collimator lens 16b1 and the tilt correction lens 18b, is reflected by the dichroic mirror 222, passes through the dichroic mirror 22b, and enters the reflection mirror 26. Therefore, the laser beam L2 is transmitted to the photosensitive material 36 along the optical path 24 through which the laser beam L1 described above has passed.
irradiates the first pixel of the image 44a. Furthermore, the third
The laser beam L3 derived from the semiconductor laser 14C passes through the collimator 1/lens 16c and the tilt correction lens 18C, is reflected by the dichroic mirror 22b, and reaches the cylindrical mirror 34 from the reflection mirror 26, resulting in an image 44a.
irradiate the first pixel of.

Here, if + is colored in the coloring material in the first pixel,
In the laser beams Li SL2 and L3 irradiated to the first pixel, the coloring material absorbs the laser beam L+ existing in the + absorption wavelength range, so the condensing bar 38 collects the laser beam L2.

will be irradiated. Therefore, the color image information corresponding to the first pixel is transmitted to the photomultiplier 4Qa,
4ON) to the image processing circuit 42 as an electrical signal.

Furthermore, if the first semiconductor laser 14a to the third semiconductor laser 14C are driven as described above, the polygon mirror 3
0 rotates in the direction of the arrow, each pixel of the images 44a, 44b is scanned by the laser beams L+, L2, and L2, and as a result, two-dimensional scanning is performed on the photosensitive material 36. The transmitted laser beams L+, L2 and 1.3 are introduced into a condensing bar 38 and photomultipliers 40a and 40b provided at both ends of the condensing bar 38.
After being subjected to photoelectric conversion, the electrical signal is sent to the image processing circuit 42. In this case, laser beam L+ SL2
When reproducing the color image information read from the photosensitive material 36 through L3 and L3 as a visible image, magenta and cyan are visually more sensitive to shifts and fluctuations than yellow, so the particles are the largest and have the best characteristics. It is desirable that 1 corresponds to yellow, which is less sensitive to noise, for the inferior coloring material. Therefore, in effect, the laser light and the blue light (
B), and the laser beams L2 and L2 are made to correspond to red light (R) and green light (G), respectively.

Note that the barcode 46 of the photosensitive material 36 is first read by the laser beams LL-L2 and L3, and the characteristic data of the photosensitive material 36 is sent to the image processing circuit 42 to correspond to the respective images 44a and 44b. A color correction calculation formula (described later) has been selected.

Therefore, the exposure amount C of the first pixel of images 44a and 44b
1, Mi, and Yl are determined based on the following color correction calculation formula.

Here, a-th to a33 are correction coefficients that take into account characteristics of filters and the like.

In this way, after the image processing circuit 42 obtains the exposure amount Ci, M, and Y corresponding to the actual color image information of each pixel from the color image information recorded on the photosensitive material 36, this information is shown in the figure. For example, a desired color image is reproduced on photographic paper.

In this case, a pattern for gray balance calibration is recorded in advance in the photosensitive material 36, and the pattern is read first, and the output when reading out the images 44a, 441), which are the main patterns, is adjusted to a predetermined value. You can also do that. As a result, it becomes possible to automatically correct the collapse of color balance caused by the photographing environment, the developing conditions, and even the fluctuations in the output of the successive three-wavelength lasers L+, L2, and L3. Moreover, even better calibration can be achieved by providing the calibration pattern with a plurality of steps from low density to high density.

Note that it is also possible to reproduce and record color images on film or the like using the image scanning device 10.

At that time, laser beams L+, L2 and L2 derived from the first semiconductor laser 14a to the third semiconductor laser 14C,
is modulated under the driving action of a modulator (not shown). Next, for example, by changing the angle of the cylindrical mirror 34 and changing the imaging position, the laser beams L+, L2, and L3 are
The color image recording operation may be performed by main-scanning a film (not shown) that is conveyed in a sub-scanning direction. Here, an optical path switching mirror may be placed in the optical path 24, and the same optical path 24 may be used, and a recording film may be used instead of the photosensitive material 36 to perform sub-scanning in the direction of arrow B. It is also possible to record while transporting.

In this case, in this embodiment, shading does not occur unlike in the conventional case where illumination lamps such as halogen lamps are used, and high resolution can be obtained to perform uniform and highly accurate color image reading work. You can. Furthermore, compared to a large and expensive gas laser, the first semiconductor laser 14a to the third semiconductor laser 14C are considerably cheaper and smaller. As a result, the image scanning device 10 incorporating the first semiconductor laser 14a to the third semiconductor laser 14c can be easily miniaturized as a whole, and has the advantage of being extremely economical. This allows the image scanning device 10 to, for example,
When incorporated into an image scanning recording/reproducing system, the effect is that the entire system can be made smaller and the manufacturing cost can be reduced.

In addition, in this embodiment, by sequentially driving the first semiconductor laser 14a to the third semiconductor laser 14c, the image 4
Laser light on each pixel of 4a, 44b, 1SL2 and L
3 is sequentially irradiated, but the image can be read by the following procedure.

That is, first, the first semiconductor laser 14a is driven to irradiate the entire surface of the image 44a with laser light.

Next, the entire surface of the image 44a is irradiated with the laser beam L2 under the driving action of the second semiconductor laser 14b, and then the entire surface of the image 44a is irradiated with the laser beam L3 under the driving action of the third semiconductor laser 14c. The color image information of the image 44a is read.

Note that, depending on the maximum and minimum transmittance of the photosensitive material 36, the first
By controlling the light emission amount and photoelectric amplification factor of the third semiconductor lasers 14a to 14c, it is possible to obtain a clear image with a low S/N ratio.

[Effects of the Invention] As described above, according to the present invention, three semiconductor lasers each emitting laser light of a different wavelength, and a photosensitive material having an absorption wavelength range corresponding to each laser light, are used. The photosensitive material carrying color image information in advance is irradiated with laser light derived from a semiconductor laser, and the reflected light is converted into an electrical signal by a photoelectric conversion element to obtain desired color image information. In this way, since a semiconductor laser is used, uniform and highly accurate color image information can be obtained, and an accurate visible image can be formed based on this information. Furthermore, semiconductor lasers are smaller and cheaper than gas lasers and the like, and have the advantage that the entire image scanning device incorporating this semiconductor laser can be manufactured economically and compactly all at once.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments.
Of course, various improvements and changes in design are possible without departing from the gist of the present invention.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a perspective explanatory diagram of a schematic configuration of an image scanning device according to the present invention, Fig. 2 is an absorption wavelength characteristic diagram of a photosensitive material used for reading in the image scanning device, and Fig. 3 2 is an explanatory front view of the photosensitive material shown in FIG. 2. FIG. 10... Image scanning devices 14a-14C... Semiconductor lasers 161-16c... Collimator lenses 18a-18c
...Correction lens 20...Reflection mirrors 22a, 22
b... Gicroic mirror 36... Photosensitive material
42...image processing circuit +-3...coloring material

Claims (1)

[Claims] (1) Consisting of a main scanning system that irradiates an image recording carrier with a light beam deflected in the main scanning direction, and a sub-scanning transport system that transports the image recording carrier in a direction substantially perpendicular to the main scanning direction, The main scanning system is equipped with first to third semiconductor lasers that emit laser beams within the respective absorption wavelength ranges in correspondence with the image recording carrier containing three types of coloring materials each having a different absorption wavelength range, and is equipped with a While conveying the image recording carrier carrying image information in the sub-scanning direction, each laser beam derived from the first to third semiconductor lasers is irradiated in the main scanning direction, and the light from the image recording carrier is transferred to a photoelectric conversion element. An image scanning device characterized in that it is configured to perform photoelectric conversion to obtain desired color image information.