JP2000131774A - Printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture printing device by which a picture displayed by a picture display device can be printed on a photosensitive material with high resolution even when the enlarging magnification of the picture is large or a photographic paper wide in width is used. SOLUTION: In this picture printing device, the photographic paper 7 is exposed by two exposure mechanisms EA and EB arranged in the width direction of the paper 7. When the width of the paper 7 is identical, the resolution of the printed picture formed on the paper 7 becomes two times in the width direction of the paper 7 and the quality of the printed image is drastically enhanced in comparison with a conventional picture printing device. Besides, the wide photographic paper 7 can be exposed without lowering the resolution in comparison with the conventional picture printing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus and, more particularly, to a digital micromirror apparatus.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image printing apparatus capable of printing an image composed of a large number of pixels displayed by a digital image display device such as a CD (liquid crystal display) and a CRT on a photosensitive material at a high resolution. .

[0002]

2. Description of the Related Art Light accompanying an image (hereinafter, referred to as a digital micromirror device, LCD, CRT, etc.) emitted from a digital image display device (for example, a digital micromirror device, an LCD, a CRT, etc.) displaying an image composed of a large number of pixels. This is called "image light.")
An image printing apparatus that irradiates a photosensitive material (e.g., photographic paper or the like) conveyed by a conveying unit to expose the photosensitive material and print the image on the photosensitive material has been conventionally known. I have.

In such an image printing apparatus, an image included in image light emitted from an image display apparatus is usually stretched by a printing lens (magnifying lens) to form an image on a photosensitive material surface. Printed on photosensitive material. At that time, when viewed microscopically, each pixel on the image display device is individually printed on the photosensitive material, so that an image printed on the photosensitive material (hereinafter, referred to as a “printed image”) Each pixel on the image display device and 1
It is composed of a large number of pixels corresponding to one.

[0004]

As described above, in an image printing apparatus in which an image displayed by an image display device is printed on a photosensitive material, as described above, the printed image is composed of a large number of pixels on the photosensitive material. Therefore, the resolution of the printed image, that is, the image quality is substantially determined by the number of pixels, that is, the pixel density per unit length or unit area of the photosensitive material.

For this reason, when the enlargement ratio of the image from the image display device to the photosensitive material (the enlargement ratio of the printing lens) is large, the resolution of the printed image is reduced, and a high-quality image cannot be obtained. is there. For example,
When the number of pixels of the image display device in the direction corresponding to the width direction of the photosensitive material (the direction perpendicular to the photosensitive material transport direction on the spread surface of the photosensitive material) is 1280 dots, the image displayed by the image display device is 4 dots. When printing on an inch-width photosensitive material, the resolution of the printed image (pixel density)
Is 320 dpi (dots / inch), and a relatively high quality printed image can be obtained. However, when the image is printed on a photosensitive material having a width of 12 inches, the resolution of the printed image becomes 106.7 dpi, and the image quality of the printed image is considerably deteriorated.

When the enlargement ratio of the image from the image display device to the photosensitive material is small, the resolution of the printed image is relatively high, but the exposure process can be performed on a wide photosensitive material (image printing). There is a problem that can not be.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is intended to solve the problem even when the image enlargement ratio from the image display device to the photosensitive material is large or when a wide photosensitive material is used. It is necessary to solve the problem of providing a printing apparatus (image printing apparatus) capable of printing an image displayed by an image display device on a photosensitive material with high resolution and forming a high-quality printed image on the photosensitive material. Make it an issue.

[0008]

A printing apparatus (image printing apparatus) according to the present invention has been made to solve the above-mentioned problems.
Discloses a method of irradiating a photosensitive material (for example, photographic paper) conveyed by a conveying means with light (including) an image including a large number of pixels displayed by an image display device to expose the photosensitive material. In a printing apparatus that is configured to print the image on a photosensitive material by the exposure processing, a plurality of exposure means are provided, and each of the exposure means corresponds to the number of the photosensitive materials according to the number of the exposure means. The exposure processing is performed on a corresponding one of a plurality of exposure areas divided in a direction perpendicular to the photosensitive material transport direction (that is, the photosensitive material width direction). is there. The plurality of exposure means are usually arranged in a line in the width direction of the photosensitive material.

In this printing apparatus, various types of digital image display devices of a reflection type or a transmission type can be used as the image display device. Specifically, for example, a digital micromirror device (DMD), a reflective LCD,
Examples include a transmissive LCD, a transmissive PLZT panel, and a CRT. Note that the digital micromirror device includes a plurality of micromirrors that can switch the reflection direction, and the image can be displayed by switching the reflection direction of each micromirror so as to correspond to the image. A reflective image display device that can be used, and is particularly suitable for use as an image display device of a printing apparatus according to the present invention.

In this printing apparatus, line exposure and surface exposure can be used as the exposure method for the photosensitive material. Here, the line exposure means a strip-shaped (elongated rectangular) exposure processing area that is elongated in a direction perpendicular to the photosensitive material transport direction (that is, the photosensitive material width direction) while the photosensitive material is continuously moved by the transport means. This is an exposure processing method in which an exposure processing is sequentially performed every time. As the line exposure, there are literally an exposure method of exposing one line (one line) at a time and a plurality of lines (scrolling an image of an image display device in the photosensitive material transport direction in synchronization with movement of the photosensitive material). Any of the exposure methods of simultaneously performing exposure over a plurality of rows can be used. In addition, surface exposure means that while the photosensitive material is intermittently moved by the transport means, exposure processing is performed on a planar (eg, rectangular) exposure processing area (eg, an exposure area for one frame) when the movement of the photosensitive material is stopped. This is an exposure method to be applied.

According to the printing apparatus of the present invention, each image (pixel) displayed by a plurality of image display devices is connected to the width direction of the photosensitive material and is printed on the photosensitive material. The resolution (pixel density) of the printed image in the width direction of the photosensitive material is increased according to the number. For example, when two exposure units (image display devices) are provided, the resolution of the printed image in the width direction of the photosensitive material can be doubled. In the case of line exposure, the resolution (pixel density) can be increased in the photosensitive material transport direction in the same manner as in the photosensitive material width direction, for example, by adjusting the moving speed of the photosensitive material or the scroll speed of the image display device. . Therefore, even when the enlargement ratio of the image from the image display device to the photosensitive material is large or when a wide photosensitive material is used, the image displayed by the image display device can be printed on the photosensitive material with high resolution, and the photosensitive material can be printed. A high quality printed image can be formed on the material. In addition, it is possible to print an image with relatively high resolution (perform exposure processing) even on a photosensitive material having an extremely wide width.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, two sets of exposure mechanisms (exposure means) each having a digital micromirror device (DMD) are arranged in a line in the photographic paper width direction (photosensitive material width direction). An embodiment of the present invention will be specifically described by taking an image printing apparatus (printing apparatus) in which an image displayed by a micromirror apparatus is printed on photographic paper by a line exposure method as an example. As the line exposure, there is an exposure method of literally exposing one line (one line) at a time, and a plurality of lines (an image) of a digital micromirror device are scrolled in the photographic paper transport direction in synchronization with the movement of the photographic paper. Any of the exposure methods of simultaneously performing exposure over a plurality of rows can be used.

As shown in FIG. 1, an image printing apparatus 1 according to the present invention substantially comprises an exposure printing processing section 2, a development processing section 3, and a drying processing section 4. Then, in the exposure printing processing unit 2, after the photographic paper 7 wound around the paper roller 6 in the paper magazine 5 is pulled out from the paper magazine 5, the photographic paper transport mechanism (transport) provided with the transport roller 13 and the like is provided. by means), and is conveyed in the direction indicated by arrow a ₁ and arrow a _2. The photographic paper 7 is continuously moved in the transport direction at a constant speed by the photographic paper transport mechanism.

In the exposure printing unit 2, the light (white light) emitted from the light source 8 (for example, a halogen lamp) is converted into R (red), G
The light passes through a color filter (not shown) of either (green) or B (blue), and is converted into monochromatic light L ₁ of R, G or B to be incident on the digital micromirror device 10. The color wheel 9 rotates intermittently at regular intervals according to the speed of the exposure processing, and sequentially switches the color filters through which light is to be transmitted. That is, the color of the monochromatic light L _1, for each predetermined time, R,
Switching is repeated in the order of G and B. If the switching timing between the color wheel 9 and the color filter can be synchronized, the color wheel 9 may be switched by continuous rotation instead of intermittent rotation as described above.

The digital micromirror device 10
A reflected light, the image light L ₂ to the digital micromirror device 10 is accompanied by an image to be displayed, the printing lens 1
The image light L ₃ is extended by 1 (extension lens), and the extended image light L ₃ is irradiated on the photographic paper 7, and the photographic paper 7 is subjected to an exposure process. Thus, the image displayed by the digital micromirror device 10 is stretched by the printing lens 11 to form an image on the printing paper 7, and the image is printed on the printing paper 7. The exposure or printing is performed by R, G and B
Are performed repeatedly for the three monochromatic lights. That is,
The R, G, and B images are printed on the same exposure area of the printing paper 7 in an overlapping manner.

The printing paper 7 on which the image has been printed as described above.
Is transported from the exposure printing processing section 2 to the developing processing section 3 by a photographic paper transport mechanism having transport rollers 13 and the like.
Then, the printing paper 7, while meandering developing unit developing solution tank 12 provided in the 3 to move generally in the arrow A ₃ direction is developed by the development processing solution. Thereafter, the printing paper 7 that has been developed is conveyed from the developing section 3 to the drying unit 4 by print paper transporting mechanism, is dried while moving the drying unit 4 in the arrow A ₄ direction, the image printing It is taken out of the device 1.

Hereinafter, a specific configuration and functions of the digital micromirror device 10, which is a reflection type digital image display device, will be described. As shown in FIG. 2A, the digital micromirror device 10 has a plate-like outer shape having a substantially rectangular spreading surface, and has a substantially rectangular micromirror portion in a frame portion 14 forming a housing in plan view. 15 are arranged. Then, as shown in FIG. 2B, a large number of micromirror units 15 (6 in FIG.
(Only the illustrated number of micromirrors 16 are arranged in a grid pattern). Substantially square in plan view, each of the micromirrors 16, the dimension H ₁ in the lateral direction (corresponding to the printing width direction) dimension D ₁ and vertical (corresponding to the printing paper conveying direction) are both generally 16μm approximately Are arranged so that the horizontal interval D ₂ and the vertical interval H ₂ are both approximately 1 μm. In the digital micromirror device 10 (SXGA standard), 1280 micromirrors 16 are arranged in the horizontal direction (1280 pixels) and 1024 micromirrors are arranged in the vertical direction (1024 pixels). Each micro mirror 16
Respectively correspond to one pixel.

As shown in FIG. 2C, each of the micro mirrors 16 (16a, 16b) has a structure in which a mirror plate 17 is supported by a yoke 18 via a support column 19. Although not shown in detail, the yoke 18 is rotatably connected to the substrate 20 via a connection structure. Here, when a memory element (not shown) arranged on the substrate 20 below each yoke 18 is energized, the state is shown, for example, on the left-side micro mirror 16a in FIG. 2C. Thus, the yoke 18 is rotated and inclined by the electrostatic action of the memory element until the left end of the yoke 18 contacts the substrate 20. In this state, the normal line S ₁ of the mirror plate 17 is inclined leftward by a predetermined angle θ with respect to the vertical line S ₀ (+ θ). That is,
The reflecting surface (spreading surface) of the mirror plate 17 is tilted to the left by θ (hereinafter, this state of the micromirror is “on”).
). At this time, the reflected light of the micromirror 16a is applied to the printing lens 11 and thus the photographic paper 7.

On the other hand, when the memory element is not energized, for example, the right-side micro mirror 16b in FIG.
As shown in FIG. 2, the yoke 18 is rotated and inclined by the electrostatic action of the memory element until the right end thereof contacts the substrate 20. In this state, the normal S ₂ of the mirror plate 17 is inclined rightward by a predetermined angle θ with respect to the vertical line S ₀ (−θ). That is, the reflection surface of the mirror plate 17 is inclined rightward by θ (hereinafter, this state of the micromirror is referred to as “off”). At this time, the reflected light of the micromirror 16b is not irradiated on the printing lens 11 (the photographic paper 7), but is absorbed by a light absorbing plate (not shown).

Thus, the digital micromirror device 1
0 switches (sets) the on / off state of each micromirror 16 based on digital image data corresponding to an arbitrary image so as to correspond to the image. That is, the micromirror unit 15 of the digital micromirror device 10 displays an image in which each micromirror 16 has one pixel (one pixel). Here, the time required to switch on / off each micromirror 16 is about 10 microseconds.

Hereinafter, the specific structure and function of an exposure mechanism (exposure means) including the digital micromirror device 10 and the printing lens 11 will be described. As shown in FIG.
In this image printing apparatus 1, a first exposure mechanism EA having two exposure mechanisms, namely, a digital micromirror device 10a and a printing lens 11a, and a second exposure mechanism having a digital micromirror device 10b and a printing lens 11b.
The exposure mechanisms EB are arranged in a line in the Y _{1 to} Y ₂ directions, that is, in the photographic paper width direction.

Here, the exposure area 21 of the photographic paper 7 (the area where the exposure processing or the printing processing is actually executed) is Y _1.
~Y is bisected in _two directions (printing paper width direction), the Y ₁ side is formed first exposure region 21a, it is formed second exposure area 21b on the Y ₂ side. Then, the first exposure area 21a
Is subjected to exposure processing by a first exposure mechanism EA, and the second exposure area 21b is subjected to exposure processing by a second exposure mechanism EB.

[0023] Then, in the image printing apparatus 1, the printing paper 7 is being continuously conveyed at a constant speed in the X ₁ direction, the exposure processing is performed by a line exposure type. That is, Y _{1 to} Y ₂
Elongated rectangular (strip-shaped) exposure area 21 which is long in the direction
(21a, 21b) each, X ₁ direction (paper conveyance direction)
Are sequentially subjected to an exposure process.

As described above, since the exposure processing is performed by the two exposure mechanisms EA and EB arranged in a line in the Y ₁ to Y ₂ directions, if the width of the photographic paper 7 is the same, Y ₁ to Y ₂ direction resolution baking image formed (pixel density) is doubled as compared with the conventional image printing apparatus, the image quality of the baked image is greatly enhanced. If the resolution is the same as the conventional one, the exposure processing can be performed on the photographic paper 7 having a double width.

By the way, as described above, Y ₁ to Y ₂
When the resolution in the direction (print paper width direction) is doubled,
₁ resolution (pixel density) of the to X ₂ direction (paper conveyance direction) must also be increased to twice. In this case, since the exposure process the paper 7 by a line exposure type while continuously moving is performed, the thus enhance X ₁ to X ₂ direction resolution must be changed to the timing of the exposure process .

That is, in order to perform color output,
Must be exposed with three monochromatic lights of R, G and B,
In addition, since it is necessary to obtain a contrast, it is necessary to perform the same spot several times (at least three times) in order to form one dot (pixel) on the printing paper 7. Even if the resolution is increased and the dots become smaller, the moving speed of the photographic paper 7 does not change.
In this case, the exposure process is performed every time one dot is moved. However, the exposure process is performed only once every two dots. Therefore, it is necessary to speed up (double) the movement (scroll) of the micromirror 16 of the digital micromirror device 10.

If the movement of the micromirror 16 cannot be accelerated due to the structure of the digital micromirror device 10, if the exposure method is a multi-row micromirror 16
The number of lines of the micromirror 16 to be used may be doubled by utilizing the fact that the line exposure is performed by using. This problem can also be dealt with by reducing the moving speed (transport speed) of the photographic paper 7 to half.

For example, as shown in FIG. 3B, a conventional lithographic printing paper 7 is exposed by using only one exposure mechanism E having a digital micromirror device 10 and a printing lens 11. In the exposure processing method, R, G or B
Monochromatic light L ₁ (see FIG. 1), SXGA standard (corresponding to the transverse direction (printing paper width direction) is 1280 pixels, the vertical direction (corresponding to the paper transport direction) is 1024 pixels) digital micromirror Micromirror unit 1 of device 10
Some areas of 5 (e.g., the lateral direction is 1280 pixels, the vertical direction 400 region of the pixel) is reflected by the image light L ₃ comprising elongated reflected light or image light L _2, a constant A print image is formed by line exposure to irradiate the photographic paper 7 moving at a high speed. At this time, each micromirror 16 of the digital micromirror device 10 (FIG. 2)
(See (c)) repeats on / off in accordance with the image data.

As described above, when only one exposure mechanism E (digital micromirror device 10) is used, the number of the micromirrors 16 is 12 in the horizontal direction (the width direction of the printing paper).
Since the number is set to 80, exposure processing of 1280 dots or more in the width direction is impossible regardless of the width of the photographic paper 7 (exposure processing of 1280 dots or less is possible). . In other words, when the exposure process is performed on the photographic paper 7 having a large width, the resolution is degraded only by increasing the size of each dot. For example, the resolution when printing on a photographic paper 7 having a width of 4 inches is 320 dpi, whereas the resolution when printing on a photographic paper 7 having a width of 12 inches is 106.7 dpi.

On the other hand, in the image printing apparatus 1 according to the present invention, as described above, the two exposure mechanisms EA and EB are arranged in a line in the width direction of the photographic paper, and each of the digital micromirrors 10a and 10b is provided with a single color. applying light L _1, 2 single printing lens 11a, so that to form an image with 11b. Here, both digital micromirror devices 10
Since the images displayed by a and 10b are connected to one, the number of micromirrors 16 in the horizontal direction (the photographic paper width direction) is 2560 in a pseudo manner. When the exposure processing is performed in this manner, the resolution when using the photographic paper 7 having a width of 4 inches is 640 dpi, and the resolution when using the photographic paper 7 having a width of 12 inches is 213.3 dpi. Therefore, the resolution is doubled as compared with the case where the exposure process is performed using only one exposure mechanism E (digital micromirror device 10).

Therefore, in the image printing apparatus 1 according to the present invention, even when the enlargement rate of the image from the digital micromirror device 10 to the photographic paper 7 is large, or when the photographic paper 7 having a wide width is used, the image is printed at a high resolution. Thus, the image can be printed on the photographic paper 7, and a high-quality printed image can be formed on the photographic paper 7. In addition, an exposure process (printing process) can be performed on a very wide photographic paper 7 without lowering the resolution of a printed image.

In this embodiment, the exposure mechanism E
The digital micromirror devices 10, 10a, and 10b are used as A and EB image display devices. However, the image display devices are not limited to digital micromirror devices, and various types of reflective or transmissive digital image displays are used. An apparatus can be used. For example, a reflective LCD, a transmissive LCD, a transmissive PLZT panel, a CRT, or the like can be used. The exposure processing may be performed by combining these image display devices.

Further, in this embodiment, the exposure processing is performed by the line exposure method. However, the exposure processing method is not limited to the line exposure method, and the exposure processing may be performed by the surface exposure method. Good.

[Brief description of the drawings]

FIG. 1 is an elevational view showing a schematic configuration of an image printing apparatus according to the present invention.

FIG. 2A is a plan view of a micromirror device, and FIG. 2B is an enlarged plan view of a micromirror constituting the micromirror device shown in FIG.
(C) is an elevation view of the micro mirror.

FIG. 3A is a perspective view of an exposure unit of an image printing apparatus according to the present invention having two exposure mechanisms, and FIG.
FIG. 2 is a perspective view of an exposure unit of the image printing apparatus including only one exposure mechanism.

[Explanation of symbols]

E: Exposure mechanism, EA: First exposure mechanism, EB: Second exposure mechanism, 1: Image printing apparatus, 2: Exposure printing processing section, 3: Development processing section, 4: Drying processing section, 5: Paper magazine, 6 …
Paper roller, 7: photographic paper, 8: light source, 9: color foil, 10: digital micromirror device, 10a ...
Digital micromirror device, 10b Digital micromirror device, 11 Printed lens, 11a Printed lens, 11b Printed lens, 12 Processing bath, 13
Conveyance roller, 14 ... frame part, 15 ... micro mirror part,
16 micromirror, 16a micromirror, 16
b: micro mirror, 17: mirror plate, 18: yoke, 19: support, 20: substrate, 21: exposure area, 21
a: First exposure area, 21b: Second exposure area.

Claims (4)

[Claims] An exposing means for irradiating a photosensitive material conveyed by a conveying means with light accompanying an image composed of a large number of pixels displayed by an image display device to perform an exposing process on the photosensitive material; In a printing apparatus configured to print the image on the photosensitive material by the exposure process, a plurality of the exposure means is provided, each exposure means,
The photosensitive material is exposed to a corresponding one of a plurality of exposure areas divided in a direction perpendicular to the photosensitive material transport direction according to the number of exposure means. Printing equipment. 2. The image display device according to claim 1, further comprising a plurality of micromirrors each of which can switch a reflection direction, and displaying the image by switching a reflection direction of each micromirror so as to correspond to the image. 2. The printing device according to claim 1, wherein the printing device is a digital micromirror device. 3. A method of exposing a photosensitive material, wherein the photosensitive material is continuously moved by the transporting means, and is sequentially exposed to each of strip-shaped exposure processing areas which are long in a direction perpendicular to the photosensitive material transport direction. 3. The printing apparatus according to claim 1, wherein the exposure is performed by line exposure. 4. A method according to claim 1, wherein the photosensitive material is subjected to a surface exposure method in which the photosensitive material is intermittently moved by the transporting means, and a planar exposure processing area is exposed when the movement of the photosensitive material is stopped. 3. The printing apparatus according to claim 1, wherein