JPH07329363A - Optical printer - Google Patents

Abstract

PURPOSE:To provide an optical printer in which the chromatic aberration which becomes a problem in the case of color printing can be simply eliminated. CONSTITUTION:The optical printer comprises light emitting means 1 for irradiating at least with red, green and blue lights based on image information, a condensing optical system 3 for condensing the lights irradiated from the means 1 on a photosensitive member 4, and support or discharge means 5 for the member 4. Accordingly, the printer for forming an image on the member 4 comprises optical elements for focusing the color lights at the same position of the member 4 by eliminating the chromatic aberrations of the respective red, green and blue lights between the means 1 and the system 3 and/or between the system 3 and the member 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical printer which exposes a photoreceptor based on image information to form an image on the photoreceptor.

[0002]

2. Description of the Related Art Printers for making hard copies of computer information, video images, etc. have been in general need, especially for color printers, as the quality of image information has improved and the accessibility has improved. There are various printing methods (methods) in color printers. For example, an electrophotographic method in which a charge latent image formed by exposure is developed with toner, an inkjet method in which ink is ejected from fine holes, a thermal transfer method in which ribbon-shaped ink is transferred by heating, and sheet-shaped ink is also sublimated by heating. The thermal sublimation method for printing is currently the main color printing method.

Among such printing methods, a film printer using a printing method in which a signal light based on image information is irradiated to directly draw on a printing film (currently almost a silver salt material) as a photoconductor. Is known as a printer that is simple and can obtain relatively high quality prints. As the photosensitive film which is a photoreceptor, a 35 mm film for general photography is used in many cases, and a film for slide and an instant film (self-developing type film) are also used.

As the light emitting means which is a signal light source, for example, a light emitting diode LED, an EL (electroluminescence) element or the like which emits monochromatic (three primary color) light can be used, as well as one capable of emitting three primary colors for a color printer. In addition, a CRT having a broad wavelength dispersion, a fluorescent display tube, a flash lamp, or the like that emits white light, and an optical filter (each color filter) that performs color separation,
It has been proposed to use and some have been commercialized.

When the photosensitive member is exposed by the scanning method using the light emitting means, the polygon mirror, the lens system and the like, the exposure takes a long time because the exposure is performed while scanning, and high speed printing cannot be performed. Moreover, since the polygon mirror, the lens system and the like are used, the size of the apparatus becomes large. Therefore, a line-shaped light emitting head composed of a line-shaped light emitting pixel (three light emitting pixels arranged on a line) light source of one line for each color (red, green, blue) (total of three lines) is used as a light emitting means. Has been.

The light of each color (red, green, blue) obtained from such a light emitting means is passed through a condensing optical system to a photoreceptor (for example,
Concentrated on the instant film, each color (red,
Exposures corresponding to the green and blue lights are performed.

[0007]

However, since the condensing optical system (for example, SELFOC lens array SLA which is a lens system in which optical fibers are bundled) has chromatic aberration,
In the case of color printing, there is a problem that the condensing position on the photoconductor is different for each color (red, green, blue) light (FIG. 8,
9).

Therefore, in order to solve the problem of chromatic aberration,
As a light emitting means, a device that emits white light is provided with an optical filter (each color filter) for color separation,
Further, a method of condensing each color light at the same position by changing the thickness of the optical filter (each color filter) is considered. However, it is difficult to control the thickness of the filter, and when the thickness of the filter is changed for each color light, the transmittance of each color light also changes, which is not practical.

An object of the present invention is to provide an optical printer which can easily eliminate chromatic aberration which is a problem in color printing.

[0010]

Therefore, firstly, the present invention provides "a light emitting means for emitting at least red, green, and blue light based on image information, and light emitted from the light emitting means on a photoreceptor. An optical printer having a condensing optical system for condensing and a means for supporting or ejecting the photoconductor, which exposes the photoconductor based on the image information to form an image on the photoconductor, Between the light emitting means and the condensing optical system, and / or between the condensing optical system and the photoconductor, the red,
An optical printer (claim 1) is provided, which is provided with an optical element that eliminates chromatic aberration of green, blue, and color lights and focuses each color light on the same position of the photoconductor.

Secondly, the present invention provides an optical printer according to claim 1, wherein the light emitting means is a light emitting means using a light emitting element which emits monochromatic light. provide. In addition, the present invention thirdly provides an “optical printer (claim 3) according to claim 1, wherein the light emitting means is a light emitting means using a white light source and each color filter”.

In a fourth aspect of the present invention, "the light emitting means is a light emitting means using a white light source and a mirror and a half mirror, or a white light source and a dichroic mirror. A printer (claim 4) ". Further, the present invention fifthly provides an “optical printer (claim 5), wherein the optical element is a mirror and a half mirror, or a mirror and a dichroic mirror”.

In a sixth aspect of the present invention, an optical printer according to any one of claims 1 to 5 is characterized in that a reflective optical element is provided between the condensing optical system and the photoconductor. "I will provide a. In addition, the present invention seventhly provides an "optical printer (claim 7), wherein the white light source is a light source using a fluorescent display tube, a CRT, or an EL element". provide.

[0014]

The structure and the image forming method of the optical printer of the present invention will be described based on the example shown in the drawings, but the present invention is not limited thereto. In the optical printer of the present invention, a light emitting means (eg, FL array tube using ZnO: Zn as a phosphor) 1 and a condensing optical system (eg, SELFOC lens array SL which is a lens system in which optical fibers are bundled)
A) 3 and / or between the condensing optical system 3 and the photoconductor (for example, a self-developing type instant film) 4 eliminate the chromatic aberration of the red, green, and blue lights, and remove the chromatic aberration. An optical element 2 for condensing light at the same position on the photoconductor is provided.

The light emitting means 1 has, for example, ZnO: Zn phosphor dots arranged in a line (three lines) corresponding to RGB (red, green, blue), and further each color (red, green, blue) filter F1 ,. F2 and F3 are arranged side by side in correspondence with the arrangement of the light emitting means (for example, 3-line shape) (for example, 3-line shape).
For one pixel recorded on the photoconductor 4, three (RGB) light emitting pixels of the light emitting means 1 (for example,
The phosphor part) emits light.

Further, it is preferable that the light emitting means 1 uses, for example, light emitting diodes LED, EL (electroluminescence) elements or the like that emit monochromatic (three primary color) lights arranged in a line. Further, the light emitting means 1 is preferably a light emitting means using a white light source and a mirror and a half mirror, or a white light source and a dichroic mirror, for example. In this case, the white light is split into each color (red, green, blue) light by the mirror and the half mirror or the dichroic mirror, not the color filter.

For example, as a configuration (example) of the dichroic mirror, a first dichroic mirror that reflects only red component light, a second dichroic mirror that reflects only green component light and transmits red component light, and only blue component light are provided. It is preferable to use a third dichroic mirror that reflects light and transmits red and green component light (see FIG. 4). The recording of one line of the image is made to sequentially emit light for each color of RGB by dynamic or static drive, that is, three (RGB) light emitting pixels (for example, a phosphor portion) of the light emitting means 1.
Is emitted, the image is recorded (formed) on one pixel on the photoconductor 4.

At this time, the light emitted from the light emitting means 1 emits red, green, and the like between the light emitting means 1 and the condensing optical system 3 and / or between the condensing optical system 3 and the photoconductor 4. Blue, light of each color is photoconductor 4
Each color light is reflected by the optical element provided so as to collect light at the same position. Here, the optical element (for example, a mirror and a half mirror, or a mirror and a dichroic mirror) 2 has each color (red, red,
The green and blue lights are arranged so as to be condensed at the same position on the photoconductor 4.

The optical element 2 is, for example, a mirror and a half mirror, or a mirror and a dichroic mirror. As an example of its configuration, a total reflection mirror (first mirror) 2a that reflects red component light and a green component light are provided. Dichroic mirror that reflects light and transmits red component light (second
An optical element including a mirror) 2b and a dichroic mirror (third mirror) 2c that reflects only blue component light and transmits red and green component light is preferable (see FIGS. 1 to 3).

The respective color lights passing through the optical element 2 are on the same axis as the three color lights, and are imaged at the same position on the photoconductor 4 by the condensing optical system (for example, SLA) 3 and the optical element 2. (Collected). A reflective optical element R is preferably provided between the condensing optical system 3 and the photoconductor 4. By providing the reflective optical element R, the light emitting means 1, the condensing optical system 3, and the photoconductor 4 can be arranged in parallel with each other, so that the apparatus can be downsized.

The light emitting means 1 according to the present invention includes, for example,
A light emitting means using a fluorescent display tube, a CRT, or an EL element that emits white light is preferable (claim 7). Fluorescent display tube (F
As a light emitting means using an L array tube), ZnS: Zn + In is used as a phosphor in addition to ZnO: Zn which is the phosphor.
The line head of the FL array tube using ₂ O ₃ (peak wavelength: 464 nm) uses Z as a phosphor as a CRT.
In addition to nO: Zn, Ca ₂ MgSi ₂ O ₇ : Ce ³⁺ (peak wavelength: 385 nm), Zn ₂ SiO ₄ : Ti (peak wavelength: 400 nm), ZnS: Ag (peak wavelength: 4)
A CRT line head or a CRT flat head (which can be miniaturized) using 60 nm) is preferable.

As a light emitting means using an EL element, for example, SrS: Ce, Eu or SrS: in the light emitting layer.
A head of a white light emitting EL element having a double insulation structure using PrF ₃ and Ta ₂ O ₅ for the insulating layer is preferable, and ZnS: Mn (yellow light emission), ZnS: Tb, F is used for the light emitting layer.
A head of a multi-color thin film EL element using (green light emission) or ZnS: Mn or SrS: Ce (blue green light emission) and using Ta ₂ O ₅ or Y ₂ O ₃ for the insulating layer is preferable.

Image formation by the optical printer of the present invention will be described below (see FIG. 5). First, RGB (red) suitable for outputting a color signal output from an image signal generator (one example, personal computer) by a light emitting means (one example, FL array tube) 1 by a control means (one example, interface) of an optical printer. , Green, blue) signal. Then R
Among the GB signals, the red (R), green (G), and blue (B) signals for each dot on the line to be recorded (image formation) are respectively input to the shift register in the control means.

After all the RGB signals for one line are input, the buffer in the control means is opened to operate the light emitting means driver, and the light emitting means corresponding to the R signal dots, G signal dots, and B signal dots of one line. Each light emitting pixel (one example, phosphor) of (one example, FL array tube head) 1 emits light (in the case of static drive). That is, the light emitting pixel portion corresponding to the exposed dot portion emits light, and the light emitting pixel portion corresponding to the non-exposed dot portion does not emit light.
The red light emitted from the light emitting means (monochromatic light source or white light source + color filter) 1 is between the light emitting means 1 and the condensing optical system 3, and / or the condensing optical system 3 and the photoconductor 4. It is reflected by the optical element 2 (for example, the total reflection mirror 2a that reflects the red component light) provided between and.

This red light is collected by a condensing optical system (for example, SL
A) 3 or by a condensing optical system 3 and a reflective optical element (an element provided between the condensing optical system and the photosensitive body for downsizing of the apparatus) R, a photoconductor (eg, an instant film). ) 4 is focused and exposed. Therefore, red (R)
The component light reaches the photoconductor (eg, instant film) 4, and the dots (one line) on the photoconductor are simultaneously exposed to red light.

Next, the green light emitted from the light emitting means (monochromatic light source or white light source + color filter) 1 is emitted between the light emitting means 1 and the light collecting optical system 3 and / or the light collecting optical system. It is reflected by an optical element 2 (for example, a dichroic mirror 2b that reflects green component light and transmits red component light) provided between the system 3 and the photoconductor 4. This green light is provided by the condensing optical system (one example, SLA) 3 or between the condensing optical system 3 and the reflection optical element (for the downsizing of the device, the condensing optical system and the photoconductor). Element) R, a photoconductor (example,
The film is exposed on a film (instant film) 4.

Therefore, the light of the green (G) component reaches the photoconductor (eg, instant film) 4, and the dots (one line) on the photoconductor are simultaneously exposed to the green light. next,
The blue light emitted from the light emitting means (monochromatic light source or white light source + color filter) 1 is between the light emitting means 1 and the condensing optical system 3, and / or the condensing optical system 3 and the photoconductor 4. And an optical element 2 (for example, a dichroic mirror 2 that reflects only blue component light and transmits red and green component light).
It is reflected by c).

This blue light is collected by a condensing optical system (for example, SL
A) 3 or by a condensing optical system 3 and a reflective optical element (an element provided between the condensing optical system and the photosensitive body for downsizing of the apparatus) R, a photoconductor (eg, an instant film). ) 4 is focused and exposed. Therefore, blue (G)
The component light reaches the photoconductor (one example, instant film) 4, and the dots (one line) on the photoconductor are simultaneously exposed to blue light.

Here, an optical element (for example, a mirror and a half mirror, or a mirror and a dichroic mirror) 2
Are arranged so that light of each color (red, green, blue) from the light emitting means 1 is condensed at the same position on the photoconductor 4. The respective color lights that have passed through the optical element 2 are on the same axis as the three color lights, and are imaged at the same position on the photoconductor 4 by the condensing optical system (for example, SLA) 3 and the optical element 2 (collection). Be illuminated). That is, the photoconductor 4 using the RGB light beams
Are simultaneously exposed (in the case of static drive).

By performing the above operation, recording (image formation) concerning RGB signals for one line is simultaneously performed, and similar recording is performed for each line. The photoconductor 4
Is an instant film, the instant film is discharged when all line recording is completed. Note that when the light emitting means 1 is made to emit light by dynamic driving, the exposure of the photoconductor with each color of RGB light is performed simultaneously (for example, red exposure → green exposure → blue exposure).

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0032]

EXAMPLE In the optical printer of this example, a three-color light emitting light source (an example of a light emitting means) 1 including a fluorescent display tube (a phosphor ZnO; an FL array tube using Zn) and a SELFOC lens array SLA ( Between the example of condensing optical system 3),
The chromatic aberration is eliminated by providing the optical element 2 for condensing the red, green, and blue lights at the same position on the photoconductor 4.

The fluorescent display tube (FL array tube) 1 has about 12
One line of light emitting pixels is arranged at a pitch of 0 μm. As shown in FIG. 5, each monochromatic (red, green, blue) light (signal light based on image information) has an SLA (an example of a condensing optical system) 3 and a reflective optical element (mirror) R having a focal length of about 4 cm. Is collected by the optical element 2, SLA 3,
Also, the mechanism (exposure system) moves along with the reflective optical element R to expose the self-developing type instant film (an example of a photoconductor) 4 to perform printing (image formation).

Further, the instant film 4 is fed in the discharging direction by the roller 5 using a stepping motor as a driving source. The stepping motor is 0 in 1 pulse.
It was rotated at 2000 PPS using a rotating 9 °. Image formation using the optical printer of this embodiment will be described below (see FIG. 5).

First, it is suitable for the color signal output from the image signal generator (eg, personal computer) to be output by the light emitting means (eg, FL array tube) 1 by the control means (eg, interface) of the optical printer. RGB
Convert to (red, green, blue) signal. Next, of the RGB signals, the red (R), green (G), and blue (B) signals for each dot on the line to be recorded (image formation) are respectively input to the shift register in the control means. .

After all the RGB signals for one line are input, the buffer in the control means is opened to operate the light emitting means driver, and the light emitting means corresponding to the R signal dots, G signal dots, and B signal dots of one line. Each light emitting pixel (one example, phosphor) of (one example, FL array tube head) 1 emits light (static drive). That is, the light emitting pixel portion corresponding to the exposed dot portion emits light, and the light emitting pixel portion corresponding to the non-exposed dot portion does not emit light. The red light emitted from the light emitting means (monochromatic light source or white light source + color filter) 1 is between the light emitting means 1 and the condensing optical system 3, and / or the condensing optical system 3 and the photoconductor 4. It is reflected by the optical element 2 (for example, the total reflection mirror 2a that reflects the red component light) provided between and.

This red light is collected by a condensing optical system (for example, SL
A) 3 or by a condensing optical system 3 and a reflective optical element (an element provided between the condensing optical system and the photosensitive body for downsizing of the apparatus) R, a photoconductor (eg, an instant film). ) 4 is focused and exposed. Therefore, red (R)
The component light reaches the photoconductor (eg, instant film) 4, and the dots (one line) on the photoconductor are simultaneously exposed to red light.

Next, the green light emitted from the light emitting means (monochromatic light source or white light source + color filter) 1 is emitted between the light emitting means 1 and the light collecting optical system 3 and / or the light collecting optical system. It is reflected by an optical element 2 (for example, a dichroic mirror 2b that reflects green component light and transmits red component light) provided between the system 3 and the photoconductor 4. This green light is provided by the condensing optical system (one example, SLA) 3 or between the condensing optical system 3 and the reflection optical element (for the downsizing of the device, the condensing optical system and the photoconductor). Element) R, a photoconductor (example,
The film is exposed on a film (instant film) 4.

Therefore, the light of the green (G) component reaches the photoconductor (eg, instant film) 4, and the dots (one line) on the photoconductor are simultaneously exposed to the green light. next,
The blue light emitted from the light emitting means (monochromatic light source or white light source + color filter) 1 is between the light emitting means 1 and the condensing optical system 3, and / or the condensing optical system 3 and the photoconductor 4. And an optical element 2 (for example, a dichroic mirror 2 that reflects only blue component light and transmits red and green component light).
It is reflected by c).

This blue light is collected by a condensing optical system (for example, SL
A) 3 or by a condensing optical system 3 and a reflective optical element (an element provided between the condensing optical system and the photosensitive body for downsizing of the apparatus) R, a photoconductor (eg, an instant film). ) 4 is focused and exposed. Therefore, blue (G)
The component light reaches the photoconductor (one example, instant film) 4, and the dots (one line) on the photoconductor are simultaneously exposed to blue light.

Here, the optical element 2 (for example, a mirror and a half mirror, or a mirror and a dichroic mirror)
Are arranged so that light of each color (red, green, blue) from the light emitting means 1 is condensed at the same position on the photoconductor 4. The respective color lights that have passed through the optical element 2 are on the same axis as the three color lights, and are imaged at the same position on the photoconductor 4 by the condensing optical system (for example, SLA) 3 and the optical element 2 (collection). Be illuminated). That is, the photoconductor 4 using the RGB light beams
Are simultaneously exposed.

By performing the above operation, recording (image formation) concerning RGB signals for one line is simultaneously performed, and similar recording is performed for each line. When all line recording is completed, the instant film 4 is discharged. When the FL array tube head, which is the light emitting means 1, is caused to emit light, the filament of the FL array tube has 100K.
Alternating current of Hz and 1.7 V, a voltage of 40 V was applied to the cathode, and a voltage of 35 V was applied to the anode. Then, the selection of light emission was controlled by setting the anode voltage to 35V or 0V.

Further, in accordance with the shade of the color to be developed, F
The light emission time of the L array tube (the time to apply a voltage to the anode) was changed, and gradation expression was performed for each color. For this reason, the light emission time (duty) differs for each dot. Using the optical printer of this embodiment, 6
When 40 × 480 dot color printing was carried out a number of times, good printing could be performed because there was no chromatic aberration.
At this time, the exposure was completed in about 1 second.

[0044]

As described above, according to the optical printer of the present invention, it is possible to eliminate chromatic aberration, which is a problem in color printing, with a simple structure. We can provide a printer.

[Brief description of drawings]

FIG. 1 shows a light emitting means (FL array tube, three-color filter) optical element, a condensing optical system (SL) in the embodiment.
It is a schematic sectional drawing which shows arrangement | positioning of A), a reflective optical element (mirror), and a photoreceptor (instant film).

FIG. 2 is a schematic cross-sectional view showing an example in which a three-color phosphor is used as a light emitting means in the configuration according to FIG.

FIG. 3 is a schematic sectional view showing an example in which the arrangement of FIG. 1 is changed.

FIG. 4 is a schematic cross-sectional view showing the configuration and arrangement in yet another example of the present invention (showing another example in which a dichroic mirror is used as an optical element, and the optical element also performs white light spectroscopy).

FIG. 5 is an explanatory diagram showing the configuration and arrangement of the embodiment.

FIG. 6 is an explanatory diagram showing chromatic aberration in a conventional optical printer.

FIG. 7 is an explanatory diagram showing chromatic aberration in another conventional optical printer.

FIG. 8 is a schematic cross-sectional view showing an example of a means for eliminating chromatic aberration in a conventional optical printer (an example in which the thickness of each color filter is changed).

[Explanation of symbols for main parts]

 DESCRIPTION OF SYMBOLS 1 ... Light emitting means 2 ... Optical element 2a ... 1st optical element 2b ... 2nd optical element 2c ... 3rd optical element 3 ... Condensing optical system 4 ... Photoconductor 5 ... Supporting or discharging means of photoconductor H ... Light emitting part of light emitting means R ... Reflective optical element F ... Each color light filter F1 ... Red light filter F2 ... Green light filter F3. ..Blue light filters and above

Claims (7)

[Claims] 1. At least red based on image information,
The photoconductor includes: a light emitting unit that emits light of each color of green and blue; a condensing optical system that condenses light emitted from the light emitting unit onto a photoconductor; and a support or discharge unit for the photoconductor. In an optical printer that forms an image on the photoconductor by exposing based on image information, between the light emitting means and the condensing optical system, and / or between the condensing optical system and the photoconductor. In between, the red, green, blue,
An optical printer provided with an optical element that eliminates chromatic aberration of each color light and focuses each color light at the same position on the photoconductor. 2. The optical printer according to claim 1, wherein the light emitting means is a light emitting means using a light emitting element that emits monochromatic light. 3. The light emitting means is a light emitting means using a white light source and each color filter.
The optical printer described. 4. The optical printer according to claim 1, wherein the light emitting means is a light emitting means using a white light source and a mirror and a half mirror, or a white light source and a dichroic mirror. 5. The optical printer according to claim 1, wherein the optical element is a mirror and a half mirror, or a mirror and a dichroic mirror. 6. The optical printer according to claim 1, further comprising a reflective optical element provided between the condensing optical system and the photoconductor. 7. The white light source is a fluorescent display tube, a CRT,
Alternatively, it is a light source using an EL element, and the optical printer according to claim 3.