JPH0813085B2 - Image scanning device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image scanning device, and more specifically, it is provided with three semiconductor lasers for deriving laser beams of different wavelengths, respectively, and absorptions corresponding to the laser beams are provided. By irradiating the laser light on a photosensitive material containing a coloring material having a wavelength range,
The present invention relates to a small-sized and inexpensive image scanning device capable of accurately reading color image information previously carried on the photosensitive material.

BACKGROUND OF THE INVENTION For example, in the field of printing plate making, rationalization of work processes,
2. Description of the Related Art An image scanning recording / reproducing system has been widely used in which image information carried on a document is electrically processed to produce a film original plate for the purpose of improving image quality.

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

In this case, when reading color image information carried on the original, CCD (Charge coupled) as a photoelectric conversion element is read.
device) is arranged in the main scanning direction, and a device for converting the color image information into an electric signal by irradiating the original from a lighting lamp and guiding the reflected light to each CCD has been conventionally used. There is.

However, in the above-described conventional technique, shading is likely to occur due to uneven illumination of the illumination lamp itself, and shading correction is required. Moreover, in reality, each CC
Since there is a variation in sensitivity for each D, it is necessary to correct all the pixels read by the CCD. Further, it has been pointed out that in order to read with high resolution, it is necessary to arrange a large number of CCDs in the main scanning direction with high accuracy.

Therefore, for color originals, for example, R, G, B
There has been proposed an apparatus for irradiating primary color gas laser light and introducing reflected light or transmitted light from the color original document into a photomultiplier as a photoelectric conversion element to obtain color image information. However, this type of gas laser is considerably large and expensive, and the use of three gas lasers incorporated in the device causes the size of the entire device to be considerably large and the manufacturing cost to rise. Exposed.

[Object of the Invention] The present invention has been made in order to overcome the above-mentioned inconvenience, and pays attention to a semiconductor laser which is relatively inexpensive and has a high resolution, and three types of semiconductors for deriving laser beams of different wavelengths are provided. While equipped with a laser, using a photosensitive material containing a coloring material having an absorption wavelength range corresponding to each laser light,
The photosensitive material carrying color image information in advance is irradiated with the laser beam and is converted into an electric signal by a photoelectric conversion element such as a photomultiplier to read desired color image information. It is an object of the present invention to provide an image scanning device capable of performing an image reading operation, suitable for downsizing of the entire device, and inexpensively manufactured.

[Means for Achieving the Object] In order to achieve the above object, the present invention photoelectrically converts color image information pre-recorded on an image record carrier including three kinds of coloring materials having different absorption wavelength regions. An image scanning device for reading, including three semiconductor lasers having different emission wavelengths, and a main scanning system for deflecting light beams from the three semiconductor lasers in a main scanning direction and irradiating the image record carrier. A sub-scanning transport system that transports the image record carrier in a direction substantially orthogonal to the main scan direction; and a photoelectric conversion unit that photoelectrically converts light from the image record carrier. Absorption wavelength range is about 500n each
m to 700 nm, 700 nm to 800 nm, and 800 nm to 900 nm, and the emission wavelengths of the three semiconductor lasers are within the absorption wavelength ranges of the three types of color formers, respectively.

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

In FIG. 1, reference numeral 10 indicates an image scanning apparatus according to this embodiment. The image scanning device 10 includes a first semiconductor laser 14a to a third semiconductor laser 14c, which are driven and controlled by the control circuit 12 to output laser beams L ₁ , L ₂ and L ₃ . In this case, the laser light L _{1 has} a wavelength of 830 nm and the laser light L _{2 has} a wavelength of 7
The wavelength of 50 nm and the laser light L ₃ is selected to be 670 nm.

A laser beam L is provided on the laser beam output side of the first semiconductor laser 14a.
A collimator lens 16a that makes ₁ a parallel light flux is provided, and a surface tilt correction lens 18a and a reflection mirror 20 are provided at a predetermined distance from the collimator lens 16a.
On the other hand, collimator lenses 16b and 16c are provided on the laser light output sides of the second and third semiconductor lasers 14b and 14c, respectively.
Surface tilt correction lenses 18b and 18c are provided at different distances from the collimator lenses 16a and 16b, respectively. That is, since the optical paths of the laser beams L ₁ , L ₂ and L ₃ are different from each other, it is necessary to adjust the positions of the surface tilt correction lenses 18a to 18c.

Laser light transmitted through the surface tilt correction lenses 18b and 18c
The dichroic mirrors 22a and 22b are arranged on the optical paths of L ₂ and L ₃ , and at that time, the reflection mirror 20 and the dichroic mirrors 22a and 22b have the same inclination angle, and the respective laser beams.
L ₁ , L ₂ and L ₃ are guided to the same optical path 24. Therefore, the dichroic mirror 22a transmits the laser light L ₁ and
While reflecting _2, the dichroic mirror 22b is engaged in the function of reflecting the transmitted and the laser beam L ₃ with a laser beam L ₁ and L _2.

In this way, the laser lights L ₁ , L ₂ and L _{3 that} have reached the same optical path 24 are reflected by the reflection mirrors 26 and 28, and then are irradiated on the polygon mirror 30. The polygon mirror 30 rotates in the direction of the arrow, and the laser beams L ₁ , L ₂ and L ₃ reflected by the polygon mirror 30 pass through the fθ lens 32 and are reflected by the cylindrical mirror 34, and the photosensitive material 36. The main scanning is performed in the direction of arrow A. In this case, the photosensitive material 36 is conveyed in a sub-scanning direction (direction of arrow B) substantially orthogonal to the main scanning direction via a sub-scanning conveying means (not shown), and is below the photosensitive material 36 in the main scanning direction. Extending and collecting bar 38
Is arranged. Photoelectric conversion elements, for example, photomultipliers 40a and 40b are attached to both ends of the light collecting bar 38, and the photomultipliers 40a and 40b are image processing circuits.
Connected to 42.

Next, the light-sensitive material 36 is provided with coloring materials K ₁ , K ₂ and K ₃ having different absorption wavelength ranges. As shown in FIG. 2, the coloring material K ₁ is substantially the first semiconductor laser 14
It corresponds to the laser light L ₁ derived from a, 800 to 900n
Absorb the wavelength of m. On the other hand, the coloring materials K ₂ and K ₃ correspond to the laser beams L ₂ and L ₃ emitted from the second and third semiconductor lasers 14b and 14c, respectively, and have characteristics of absorbing wavelengths of 700 to 800 nm and 500 to 700 nm. Have

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

Here, images 44a and 44b corresponding to desired color images are recorded on the photosensitive material 36 through an image capturing device (not shown) or the like. Further, the photosensitive material 36 has an identification pattern in advance,
For example, a bar code 46 is formed, and the characteristic data of the photosensitive material 36 and the identification data such as a negative image or a positive image are stored through the bar code 46.

Therefore, the photosensitive material 36 is loaded into the image scanning device 10. At this time, the photosensitive material 36 may be loaded in a container such as a cartridge, and a bar code indicating the characteristic data of the photosensitive material 36 may be formed in this container. Thus, when the container is loaded in the image scanning device 10, if the bar code is read through a sensor (not shown) provided in the image scanning device 10, the characteristic data of the photosensitive material 36 and the like can be detected in advance. Can be done.

Next, the first semiconductor laser 14a to the third semiconductor laser 14c are driven by the control circuit 12 while the photosensitive material 37 is sub-scanned and conveyed in the direction of arrow B in FIG. The pixels are sequentially driven. The laser beam L ₁ emitted from the first semiconductor laser 14a is collimated by the collimator lens 16a, passes through the face tilt correction lens 18a, and is reflected by the reflection mirror 22. Reflective mirror passing through
Up to 26. The laser beam L ₁ reflected by the reflection mirror 26 is incident on the polygon mirror 30 via the reflection mirror 28, and fθ
The light passes through the lens 32, is reflected by the cylindrical mirror 34, and illuminates the first pixel of the image 44 a formed on the photosensitive material 36.

On the other hand, the laser light L emitted from the second semiconductor laser 14b
Similarly, ₂ is a collimator lens 16b, a tilt correction lens 18b
Is reflected by the dichroic mirror 22a, passes through the dichroic mirror 22b, and enters the reflection mirror 26. Therefore, the laser beam L ₂ irradiates the first pixel of the image 44a of the photosensitive material 36 along the optical path 24 through which the laser beam L ₁ described above passes. Further, the laser beam L ₃ derived from the third semiconductor laser 14c passes through the collimator lens 16c and the surface tilt correction lens 18c, is reflected by the dichroic mirror 22b, reaches the cylindrical mirror 34 from the reflecting mirror 26, and forms an image.
Irradiate the first pixel of 44a.

Here, if the coloring material K ₁ is coloring in the first pixel,
Since the laser light L ₁ existing in the absorption wavelength range of the coloring material K ₁ is absorbed by the laser lights L ₁ , L ₂ and L _{3 with} which the first pixel is irradiated, the laser light L ₁ is collected by the focusing bar 38. ₂ and L ₃ will be irradiated. Therefore, the color image information corresponding to the first pixel is sent to the image processing circuit 42 as an electric signal through the photomultipliers 40a and 40b.

Further, as described above, when the first semiconductor laser 14a to the third semiconductor laser 14c are driven, the polygon mirror 30 rotates in the direction of the arrow, so that each pixel of the images 44a and 44b causes the laser beams L ₁ , L ₂ and L _{3 to be} emitted. Scanning results in a two-dimensional scan on the photosensitive material 36. The laser light
The transmitted light of L ₁ , L ₂ and L ₃ is introduced into the condensing bar 38 and photoelectrically converted by the photomultipliers 40a and 40b provided at both ends of the condensing bar 38, and then the electric signal is imaged. It is sent to the processing circuit 42. In this case, laser light L ₁ ,
When reproducing color image information read from the photosensitive material 36 via L ₂ and L ₃ as a visible image, magenta and cyan are visually more sensitive to shifts and fluctuations than yellow, so the particles are the largest. It is desirable to make the coloring material K ₁ having the poorest characteristics correspond to yellow, which is insensitive to noise. Therefore, substantially, the laser light L ₁ is made to correspond to the blue light (B), and the laser lights L ₂ and L ₃ are made to correspond to the red light (R) and the green light (G), respectively.

The laser beams L ₁ , L _2, and L ₃ first read the bar code 46 of the photosensitive material 36, and the characteristic data and the like of the photosensitive material 36 are sent to the image processing circuit 42 and the respective images 44.
A color correction calculation formula (described later) corresponding to a and 44b is selected.

Therefore, the exposure amount C _i of the i-th pixel of the images 44a and 44b,
M _i and Y _i are determined based on the following color correction calculation formula.

Here, a _{11 to} a ₃₃ are correction coefficients in consideration of characteristics of filters and the like.

In this way, after obtaining the exposure amounts C _i , M _i and Y _i corresponding to the actual color image information of each pixel from the color image information recorded on the photosensitive material 36 by the image processing circuit 42, this information is The image is fed to an image recording device (not shown) and, 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, first, the pattern is read, and the output when reading the images 44a and 44b, which are the main patterns, is adjusted to a predetermined value. You can also As a result, the shooting environment, development conditions, and read-out three-wavelength laser
It is possible to automatically correct the loss of the color balance caused by the fluctuation of the outputs of L ₁ , L ₂ and L ₃ . Further, 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 a color image on a film or the like by the image scanning device 10. At that time, the laser beams L ₁ , L ₂ and L ₃ derived from the first semiconductor laser 14a to the third semiconductor laser 14c are modulated under the driving action of a modulator (not shown). Then, for example, by changing the angle of the cylindrical mirror 34 to change the image forming position, the laser light is changed.
A color image recording operation may be performed by main-scanning L ₁ , L ₂ and L ₃ onto a film (not shown) which is sub-scanned and conveyed. Here, an optical path switching mirror may be arranged in the optical path 24, and the same optical path 24 is used, and a recording film is used in place of the photosensitive material 36, and this is sub-scanned in the direction of arrow B. It is also possible to record while transporting.

In this case, in the present embodiment, unlike the conventional one using an illumination lamp such as a halogen lamp, shading does not occur, high resolution is obtained, and a uniform and highly accurate color image reading operation is performed. You can do it. Furthermore, compared to large and expensive gas lasers,
The first semiconductor laser 14a to the third semiconductor laser 14c are considerably inexpensive and small in size. As a result, the first semiconductor laser 14a
To the image scanning device 1 incorporating the third semiconductor laser 14c
0 has the advantage that it can be easily downsized as a whole and is extremely economical. As a result, when the image scanning device 10 is incorporated in, for example, an image scanning recording / reproducing system, it is possible to reduce the size of the entire system and the manufacturing cost.

Further, in the present embodiment, the image 44a, by sequentially driving the first semiconductor laser 14a to the third semiconductor laser 14c,
Laser light L ₁ , L _2, and L ₃ are sequentially irradiated to each pixel of 44b, but image reading can be performed by the following procedure. That is, first, the first semiconductor laser 14a is driven to irradiate the entire surface of the image 44a with the laser beam L ₁ . Then the second
The laser beam L _{2 is applied} to the image 4 under the driving action of the semiconductor laser 14b.
After irradiating the entire surface of 4a, laser light L ₃ is irradiated to the entire surface of this image 44a under the driving action of the third semiconductor laser 14c, and the color image information of the image 44a is read.

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

[Advantages of the Invention] As described above, according to the present invention, three semiconductor lasers for deriving laser beams having different wavelengths and a photosensitive material having absorption wavelength bands corresponding to the respective laser beams are used, Each of the laser beams derived from the semiconductor laser is applied to the photosensitive material previously carrying color image information, and the reflected light is converted into an electric signal by a photoelectric conversion element to obtain desired color image information. Thus, since the semiconductor laser is used, uniform and highly accurate color image information can be obtained, and based on this, an accurate visible image can be formed. Moreover, the semiconductor laser is smaller and cheaper than the gas laser and the like, and there is an advantage that the entire image scanning device incorporating the semiconductor laser can be manufactured economically and compactly at once.

Although the present invention has been described above with reference to the preferred embodiments, the present invention is not limited to these embodiments, and various improvements and design changes can be made without departing from the scope of the present invention. Of course.

[Brief description of drawings]

FIG. 1 is an explanatory perspective view 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 is a photosensitizer shown in FIG. It is a front explanatory view of a material. 10 ... Image scanning device 14a-14c ... Semiconductor laser 16a-16c ... Collimator lens 18a-18c ... Correction lens, 20 ... Reflection mirror 22a, 22b ... Dichroic mirror 36 ... Photosensitive material, 42 ... Image Processing circuit K _{1 to} K ₃ …… Coloring material

Claims (1)

[Claims] 1. An image scanning device for photoelectrically reading color image information recorded in advance on an image record carrier containing three types of color-forming materials having different absorption wavelength regions, the three having different emission wavelengths. Semiconductor lasers, a main scanning system that deflects the light beams from the three semiconductor lasers in the main scanning direction and irradiates the image record carrier, and conveys the image record carrier in a direction substantially orthogonal to the main scanning direction. And a photoelectric conversion means for photoelectrically converting light from the image record carrier, wherein the absorption wavelength ranges of the three types of color formers are approximately 500 nm, respectively.
.About.700 nm, 700 nm to 800 nm, and 800 nm to 900 nm, and the emission wavelengths of the three semiconductor lasers are the above three, respectively.
An image scanning device characterized by being within the absorption wavelength range of various types of color developing materials.