JP3080918U - Digital exposure printing equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A conventional digital exposure printing apparatus has high equipment cost, high running cost, insufficient stability,
There are disadvantages such as insufficient speed, and further improvement in image quality is desired. Further, a system using a reflection unit (DMD) including an aggregate of a large number of movable micromirrors and capable of obtaining a large image size at low cost is desired. SOLUTION: In a digital exposure printing apparatus of a type that exposes a photosensitive material with light reflected from a light source in a reflection unit (DMD) including an aggregate of a large number of movable micromirrors, a direction perpendicular to a moving direction of the photosensitive material. In contrast, an exposure unit capable of associating a plurality of the micromirrors with each of all pixels of the exposed image is used.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a digital exposure printing apparatus for obtaining an image from a digitized image signal on a photosensitive material by exposure printing.

[0002]

[Prior art]

 Conventionally, as an example of a digital exposure printing apparatus for obtaining a visualized image from image information obtained by digitizing an analog image by means of a scanner or a digital image information such as digitalized photographing information of a digital camera, a laser is used. Examples include a beam printer and a silver salt exposure printing apparatus.

[0003] As a method of obtaining a visualized image from digital image information, a digital image information is converted into light as in the above-described exposure printing apparatus, and a latent image is once formed on a photosensitive material and then developed. In addition to the method of visualizing the latent image, a method of directly obtaining an image from an electric signal such as an ink jet printer and a sublimation type thermal printer is known.

[0004] These have characteristics in terms of image quality, speed at which images can be obtained, price, and the like, and are used depending on the purpose of use. Among them, the silver halide exposure printing method is particularly excellent in terms of photographic image quality. Therefore, when an image quality higher than the photographic image quality level is required, the silver salt exposure printing method is often used.

As this type of silver salt digital exposure printing apparatus, an apparatus using a CRT, LED, laser or the like as a light source is known. In the case of a CRT, digital image information is visualized on a CRT, the image on the CRT is formed on a silver halide photosensitive material using an optical system such as a lens, exposed, and subjected to a known development process. The LED and the laser convert the digital image information into light intensity, scan it on a silver halide photosensitive material, create a latent image, develop the latent image, and develop the latent image. This is to obtain the final image.

[0006] Recently, as a silver halide digital exposure printing apparatus, using a normal light source such as a tungsten light, the light from this light source is reflected by a reflection unit (DMD) including an aggregate of a large number of movable micromirrors. A method of exposing this light to a silver halide photosensitive material using an optical system such as a lens has been known. The reflection unit (DMD) including the assembly of the large number of movable micromirrors is provided by Texas Instruments, and is described in detail on its home page. DMD is an abbreviation of Digital Micromirror Device, and when an individual mirror receives an electric signal, it moves and changes the direction of light reflection. Each mirror has an extremely small size. The assembly of a large number of movable micromirrors and the drive circuit and device are unitized and sold as a reflection unit (DMD) including an assembly of a large number of movable micromirrors.

A reflection unit (DMD) including an aggregate of a large number of movable micromirrors is, as the most common, for example, about 1000 micromirrors in the horizontal direction and about 700 micromirrors in the vertical direction. In such a situation, the individual micromirrors are moved by electrical signals introduced into this unit.

[0008]

[Problems to be solved by the invention]

 The conventional silver halide digital exposure printing apparatus has some disadvantages. For example, a laser using a laser requires a very expensive laser light source and requires a special silver halide photosensitive material whose photographic characteristics are adjusted to the wavelength of the laser light. The use of this special light-sensitive material not only raises the cost but also has the disadvantage of increasing versatility.

For example, a device using a CRT has difficulty in stability and durability, and recently, an attempt has been made to use an LED instead of a laser or a CRT. When an LED is used, the positions of B (blue), G (green), and R (red) are different when performing color exposure as in the case of the laser. Therefore, it is necessary to devise a way to match this difference to the same pixel. Further, since the light amount of this LED is low, it is necessary to devise a method of increasing the light amount by multiple exposure. As a result of the multiple exposure, an attempt is made to improve the disadvantage of the unstable light amount of the LED by averaging the light amount of the LED. Is being done.

However, since the number of required LED chips is large, it is necessary to have as many drive circuits as the number of chips and a control circuit for correcting characteristics such as the amount of light between different LEDs. Is done. In order to facilitate multiple exposure, the photosensitive material is fixed to a rotating drum for exposure. However, in order to reduce the exposure printing time, the photosensitive material is not lifted from the drum in order to rotate the drum at a high speed. Innovative structural measures are also required. These have drawbacks of high cost or poor stability.

On the other hand, a digital exposure printing apparatus using a reflection unit (DMD) including an aggregate of a large number of movable micromirrors can freely select a light source, so that the characteristics and intensity of light can be selected. Has many advantages. However, this type of known digital exposure printing apparatus scans in the moving direction by moving the photosensitive material in a plane, so that each mirror is responsible for one pixel in a direction perpendicular to the moving direction. ing. Therefore, for example, if the number of mirrors in the right-angle direction is 1024, in order to obtain a resolution of 300 dpi (a resolution generally required), only an image having a maximum size of 3.41 inches in the right-angle direction is obtained. I can't get it. Therefore, since this is not enough, about 4000 mirrors are used in the perpendicular direction. Even in this case, the image is limited to an image of just over 13 inches at 300 dpi.

[0012]

[Means for Solving the Problems]

 The present invention solves such a problem and, for ease of understanding, mainly describes a silver halide photosensitive material. However, the present invention is not limited to this and can be applied to an electrophotographic system. is there. That is, the present invention relates to a digital exposure printing apparatus that exposes a photosensitive material with light reflected from a light source in a reflection unit (DMD) including an aggregate of a large number of movable micromirrors. The present invention relates to a digital exposure printing apparatus (1) having an exposure means capable of associating a plurality of the micro mirrors with all the pixels of an exposed image in various directions.

[0013] Further, in the digital exposure printing apparatus (1), a digital exposure printing apparatus having a lens between the reflection unit and the photosensitive material and a unit for changing a resolution by changing a magnification and / or a focus of the lens. It relates to the device (2).

Further, in the digital exposure printing apparatus (1 or 2), a red filter, a green filter, and / or a blue filter are inserted between the light source and the photosensitive material to control the color of the exposure. The present invention relates to a digital exposure printing apparatus (3) having color control means, and in the digital exposure printing apparatus (1, 2 or 3), controlling a reflection time of the reflected light to control a gradation of the image. The present invention relates to a digital exposure printing apparatus (4) having control means, and further comprises a rotatable drum and the photosensitive material fixed to the drum in the digital exposure printing apparatus (1, 2, 3, or 4). Fixed means for rotating the drum, rotating means for rotating the drum at a constant speed, and scanning means for moving the reflection unit in parallel with the rotation axis of the drum. The present invention relates to a digital exposure printing apparatus (5).

Further, in the digital exposure printing apparatus (1, 2, 3, 4, or 5), the light amount detecting means for detecting the light amount of the light source, and the light amount of the light source in response to a signal from the light amount detecting means. A digital exposure printing apparatus (6) having light quantity control means for controlling fluctuations; and in the digital exposure printing apparatus (1, 2, 3, 4, 5, or 6), the photosensitive material is silver halide photosensitive paper. The present invention relates to a digital exposure printing apparatus (7).

The digital exposure printing apparatus (1) can associate a plurality of the micromirrors with each of all pixels of an exposed image in a direction perpendicular to a moving direction of the photosensitive material. With such an exposure means, an image of a desired size can be obtained without being affected by the size of the photosensitive material. An example of the exposing means is the scanning means in the digital exposure printing apparatus (5), and is a means for exposing the photosensitive material to light from the light source beyond a long side of the micro mirror assembly. And it is possible to expose each of the pixels in the perpendicular direction using a plurality of micromirrors included in the assembly. For example, in the digital exposure printing apparatus (5), the plurality of micromirrors can use a plurality of mirrors in the moving direction of the photosensitive material for the same pixel, or use a plurality of mirrors in the perpendicular direction or a combination thereof. It is also possible to adjust the gradation of the obtained image. That is, the gradation can be adjusted by adjusting the number of micromirrors assigned to the same pixel.

The reflection unit may be any of those available, but for reflection and availability, projector units are preferred. Reflection units that can be obtained for a silver halide digital exposure printing apparatus are preferable because of the large number of micromirrors as described above, but are extremely expensive as described above. On the other hand, those used for projectors are mass-produced and are desirable in terms of cost and stability. It is produced in large quantities by Texas Instruments with product type symbols such as VGA, SVGA, XGA, and S-XGA.

The digital exposure printing apparatus (2) makes it possible to obtain an image of a desired size and an image of a desired resolution. Both the magnification change and the focal point movement of the lens can be performed, for example, by moving in the direction of the optical system axis, and known optical means for determining which lens is to be moved can be used with a simple configuration and simple operation. Become. Of course, a method of moving the fixed focus lens into and out of the optical path is also possible.

The digital exposure printing apparatus (3) uses a three-color filter as is known in a conventional analog exposure printing apparatus for a silver salt photosensitive material, and preferably includes a rotating three-color filter. Positioning the light-sensitive material between the light source and the reflection unit and synchronizing the light-sensitive material with the reflection unit enables three-color overlapping exposure on the same pixel. Alternatively, for example, as described later in detail, by providing a three-color filter adjacent to the micro mirror assembly in a slit shape, the structure and circuit for synchronous rotation can be omitted.

The digital exposure printing apparatus (4) controls an ON electric signal for controlling a reflection angle of each of the minute mirrors included in the reflection unit, and sets an ON time (a time for irradiating the photosensitive material with light). ) Can be adjusted to adjust the obtained image gradation. In short, the gradation is controlled by the pulse width modulation (PWM) method.

As described above, the digital exposure printing apparatus (5) uses an example of the exposure unit. The digital exposure printing apparatus (6) corrects the time variation of the light amount of the light source to obtain a better image, and the digital exposure printing apparatus (7) is suitable for using silver halide photosensitive paper as a photosensitive material. It is a thing.

[0022]

[Embodiment of the invention]

 Hereinafter, specific embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. FIG. 1 is a conceptual view of an exposure portion of a digital exposure printing apparatus according to an embodiment of the present invention. For a portion not shown, for example, the structure of a digital exposure printing apparatus using an LED can be used.

The light from the light source 1 passes through the rotating three-color filter 2, is reflected by the reflection unit 3, and exposes the silver halide photosensitive paper 6 via the lens 4 to form a latent image 8. . Reference numeral 5 denotes a drum, which is rotatable in the direction of the arrow. The photosensitive paper 6 is supported along the circumferential surface of the drum 5. Although not shown, digital image information is introduced into the reflection unit by a digital electric signal. According to the electric signal, each of the micromirrors of the reflection unit moves, and the latent image is formed by forming an exposed / unexposed state on the photosensitive paper according to the state of reflection of the light. . At this time, the color information of the three colors of the digital image information and the rotation of the three-color filter are synchronized, and three-color overlapping exposure is performed on the same pixel.

An exposure optical system including a light source 1, a rotating three-color filter 2, a reflecting unit 3, and a lens 4 is configured to be movable in the direction of the rotation axis of the drum. The exposure optical system moves in synchronization with the rotation of the drum, thereby performing scan exposure on the surface of the photosensitive paper. Reference numeral 7 denotes a light amount detector which detects the light amount of the light source, sends a signal to a light amount controller (not shown), and adjusts the light amount of the light source connected to the light amount controller to a constant value. The long side of the micromirror assembly of the reflection unit is arranged in the drum axis direction.

In order to adjust the gradation of the obtained image, as described above, ON time control of the electric signal introduced to the reflection unit, control of the micro mirror in the drum rotation direction, and control of the drum There is a method of controlling the micro mirror in the axial direction. For example, the time control is performed in four stages, the micromirrors in the drum axis direction are divided into four groups by using the 64 micromirrors in the rotation direction of the drum, and multiple exposure is performed by 1024 (4 × 64 × 4). Can be obtained.

FIG. 2 is a conceptual diagram of an assembly of micromirrors, and is an example in which a portion 10 of the entire assembly 9 of the micromirrors is used. The long side of the entire assembly is located parallel to the rotation axis of the drum, and the short side of the entire assembly is located in the drum rotation direction. For example, in FIG. 1, when all the mirrors of the entire assembly 9 are used, an image may be blurred due to the positional relationship between the diameter of the drum and the reflection unit. Since the entire assembly is basically flat and different from the shape of the drum surface, an image blur occurs at a position away from the optical axis in the short side direction of the entire assembly. If the blur exceeds the allowable range, the blur can be set within the allowable range by using the portion 10 instead of using the whole of the entire assembly.

FIG. 3 is a diagram showing a state of image formation in FIG. In FIG. 1, when the photosensitive paper on the drum rotating at a constant speed is exposed while moving the exposure optical system at a constant speed in parallel with the drum rotation axis, a spiral image is formed. Reference numeral 11 denotes a state in which the photosensitive material is spread, and reference numeral 12 denotes an exposure image area, which represents a state in which a spiral image is formed. The short side of the drum 11 is the drum axis direction.

In FIG. 1, since image formation is performed spirally, image distortion occurs. If the distortion exceeds an allowable level, it is necessary to correct the image distortion. FIG. 4 shows an example in which the exposure optical system is inclined to prevent distortion. Reference numeral 13 denotes a drum, and 14 denotes a silver halide photosensitive paper on the drum. The image exposure area at the n-th rotation is 15, and the image start area at the (n + 1) -th rotation is 16. The exposure optical system and the silver halide photosensitive paper are each inclined with respect to the spiral axis. For example, in the example shown in FIG. 1, the exposure optical system is appropriately rotated clockwise around the optical axes of the reflection mirror 3 and the lens 4.

FIG. 5 shows an example in which a three-color filter is provided in the reflection unit, and the rotary three-color filter 2 in FIG. 1 is omitted. Reference numeral 17 denotes an entire assembly of micromirrors, and three-color filters 19, 20 and 21 are provided on a used portion 18. 19 is a blue filter, 20 is a green filter, and 20 is a red filter. The long side direction of the micromirror aggregate is the drum axis direction. An electric signal to the reflection unit is adjusted so that respective colors overlap on the same pixel.

FIG. 6 shows another example in which a three-color filter is provided in the reflection unit. The long-side direction of the micromirror whole assembly 22 is the drum rotation axis direction. Three-color filters 24, 25 and 26 are provided in the used portion 23 of the micro mirror assembly. 24 is a blue filter, 25 is a green filter, and 26 is a red filter.

FIG. 7 shows an example of scanning the reflection unit. The vertical axis represents the moving speed of the exposure optical system, and the higher the speed, the higher the speed. The horizontal axis is the time. A is the first exposure time (scan), and B is the second exposure time (scan). For example, in FIG. 1, the reflection unit moves parallel to the drum axis at a certain speed (area A) within an allowable range of image distortion during image exposure, and at the end of image exposure (at the end of one scan). To the start of the next image exposure (the start of the next scan) (area B 1) at a high speed to the image exposure start position. During this time, the drum keeps rotating at a constant speed. By doing so, the amount of movement of the exposure optical system with respect to the rotation of the drum can be given a range.

[0032]

[Effect of the invention]

 According to the present invention, a digital exposure printing apparatus is characterized in that image formation is faster than that of a digital exposure printing apparatus using LEDs, and is cheaper than other digital exposure printing apparatuses. Since the digital exposure printing apparatus of the present invention can use silver halide photosensitive material, it has excellent image quality, does not require a special photosensitive material, and can use a photosensitive material for an analog silver halide exposure printing apparatus, thereby reducing running costs. It has a cheap effect. Further, the stability of the light source is good, and the level of the obtained image quality is high.

[0033] Compared with a known digital exposure printing apparatus using a reflection unit (DMD) including an assembly of a large number of movable micromirrors, the size of an obtained image is not limited, and its cost is high. Also has a cheap effect. Further, since the resolution and the gradation can be adjusted, a better image can be obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of one embodiment of the present invention.

FIG. 2 is an example of using a micro mirror assembly.

FIG. 3 is a conceptual diagram illustrating a state of image formation.

FIG. 4 is an example of preventing image distortion.

FIG. 5 is an example of a reflection unit having a three-color filter.

FIG. 6 is another example of a reflection unit having a three-color filter.

FIG. 7 is an example of a scan of a reflection unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light source 2 rotating three-color filter 3 reflection unit 4 lens 5 rotating drum 6 photosensitive material 7 light source light amount detector 8 exposure area 10 micro mirror assembly of used part 12 exposure area 14 photosensitive material 15 exposure area 18 three-color filter 24 blue filter 25 Green filter 26 Red filter

Claims (7)

[Utility model registration claims] 1. A digital exposure printing apparatus which exposes a photosensitive material with light reflected from a light source in a reflection unit (DMD) including an assembly of a large number of movable micromirrors. A digital exposure printing apparatus, comprising: exposure means capable of associating a plurality of said micromirrors with each of all pixels of an exposed image in a direction. 2. A digital exposure printing apparatus according to claim 1, further comprising a lens between said reflection unit and said photosensitive material, and means for changing resolution by changing magnification and / or focusing of said lens. 3. The digital exposure printing apparatus according to claim 1, further comprising color control means for inserting a red filter, a green filter, and / or a blue filter between the light source and the photosensitive material to control the color of the exposure. apparatus. 4. A gradation control means for controlling a reflection time of the reflected light to control a gradation of the image.
2 or 3 digital exposure printing apparatus. 5. A rotatable drum, fixing means for fixing the photosensitive material to the drum, rotating means for rotating the drum at a constant speed, and scanning means for moving the reflection unit in parallel with the rotation axis of the drum. Claim 1, comprising:
2, 3 or 4 digital exposure printing equipment. 6. The digital exposure printing apparatus according to claim 5, further comprising: a light amount detecting unit configured to detect a light amount of the light source; and a light amount controlling unit configured to control a light amount variation of the light source according to a signal from the light amount detecting unit. 7. The digital exposure printing apparatus according to claim 5, wherein said photosensitive material is silver halide photosensitive paper.