JPH05165108A - Color printer and fluorescent writing device - Google Patents

Abstract

PURPOSE:To obtain a small-sized, inexpensive and high speed color printer using heat developable photosensitive material and also capable of outputting a clear image. CONSTITUTION:A photosensitive member 1 moving on an exposure table 3 is exposed by using a fluorescent writing device 4 for emitting light the visible region including red, green and blue. The fluorescent writing device 4 is mainly constituted of a fluorescent writing head 41 which corresponds to each exposure by red, green and blue and a lens 46, and also, the device is improved so as to obtain a mechanism and a driving method for increasing particularily red exposure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color printer which forms a color image by using a visible light-sensitive heat developing material.

[0002]

2. Description of the Related Art Color printing methods include electrophotography, thermal transfer, ink jet, conventional photography,
Various methods have been proposed such as dry photography and one utilizing the selective curing property of microcapsules. Among them, the one utilizing the selective curing property of microcapsules (for example, JP-A-59-30537) This method is suitable for downsizing and cost reduction because it can obtain high-quality images and the image forming process is very simple. However, the sensitivity is so low that it is difficult to realize a practical optical writing device suitable for this.

Therefore, as a light-sensitive material having a similar method but higher sensitivity, for example, JP-A-61-278849.
You can list the issues. This is a photosensitive transfer type heat development material having sensitivity to visible light, and since silver is used as a trigger, high sensitivity can be obtained. Specific examples of color printing using this photosensitive material include JP-A-63-141051.

[0004]

However, the above-mentioned prior art has the following problems.

First, although the above-mentioned light-sensitive material has become high in sensitivity, it is still low in sensitivity as compared with a conventional photographic process, and its optical writing device is expensive and complicated. In addition to the combination of laser and wavelength converter mentioned in the above-mentioned conventional example, visible light source + liquid crystal shutter / PL
ZT shutters, FOTs, CRTs, etc. are also conceivable, but due to various problems such as print speed, price, gradation, shutter defects, size, etc., their functions cannot be fully fulfilled.

On the other hand, as an optical writing device other than the above,
For example, there is a fluorescent print head as disclosed in JP-A-1-95073, but its application is limited to monochrome electrophotography and the like, and there is no example applied to the heat-developable photosensitive material like the above-mentioned conventional example.

The present invention has been made in view of these circumstances and solves the above problems. An object of the present invention is to obtain a high-speed, clear image at a small size and at a low cost by using a photothermographic material. It is to provide a new color printer capable of performing.

Still another object of the present invention is to provide a color printer using a photosensitive member having a heat developing property and capable of obtaining a high quality image excellent in color balance.

[0009]

A color printer according to the present invention discharges from a cathode to a heat-developable photosensitive member having microcapsules in which at least a photosensitive material and a coloring material are encapsulated on a support. Controlled electrons with the control electrode,
Irradiate the phosphor provided in the anode part, at least red,
It is characterized in that exposure is performed by a fluorescence writing device that emits visible light containing green and blue components.

Further, it is desirable to configure the following various exposure systems.

1) A fluorescent writing device having fluorescent writing heads for red, green, and blue exposures, respectively, wherein the arrangement of each color is green, red, and blue.

2) A fluorescent writing device having fluorescent writing heads for red, green, and blue exposures, respectively, and the number of exposure dots of each color is not the same.

3) The fluorescent writing device is dynamically driven, and the driving duties of red, green, and blue exposure are not the same.

4) A fluorescent writing device provided with a switchable red, green, and blue color filter is used to form a color image by performing at least three exposures corresponding to each color, and at the same time, for each color. The exposure times should not be the same.

5) To have an auxiliary exposure device different from the fluorescent writing device.

[0016]

EXAMPLES The color printer of the present invention will be described in detail below with reference to examples.

FIG. 1 is a front sectional view showing an embodiment of the present invention. First, the operation of this machine will be described.

The unexposed continuous sheet-shaped photosensitive member 1 is housed in a cartridge 2, which is fed from here during operation and exposed by a fluorescent writing device 4 on an exposure table 3 to form a latent image. An image signal, a drive signal and the like are input to the fluorescence writing device 4 from a control device (not shown), and appropriate exposure is performed according to a desired image. After that, the photosensitive member 1 is heated and developed by the thermal developing device 6 via the conveying roller 5.

On the other hand, the cut sheet-shaped transfer member 8 stored in the paper feed tray 7 is sent out by the paper feed device 9,
The pressure transfer device 10 of the roller pressing type is superposed on the photosensitive member 1 in synchronization with the image region formed on the photosensitive member 1.
Is transferred under pressure. The pressure unit of the pressure transfer device 10 is composed of three rollers, an upper roller 11, a middle roller 12, and a lower roller 13, and pressure transfer is performed between the upper roller 11 and the middle roller 12.

Thereafter, the transfer member 8 is separated from the photosensitive member 1 by the separating roller 14 and discharged to the paper discharge tray 16 through the conveying roller 15. The photosensitive member 1 is pinched to promote the conveying and separation of the photosensitive member 1. Winding shaft 1 through roller 17
It is rolled up to 8.

Further, 19 is a manual paper feed port, and 20 is a gas filter for removing gas generated in the machine.

The photosensitive member 1 and the transfer member 8 used in this embodiment.
Is disclosed in JP-A-61-278849, and the photosensitive member 1 is sensitive to visible light, and a full-color image can be obtained on the transfer member 8.

Next, the fluorescent writing device 4 which characterizes the present invention will be described.

FIG. 2 is a schematic diagram showing a fluorescent writing device portion of the color printer of FIG. In the figure, as the fluorescent writing head 41, for example, JP-A-1-95073 is used.
Can be used.
This is a kind of fluorescent display tube in which a cathode 42, a control electrode 43, various electrodes such as an anode 44, a phosphor 45, etc. are arranged in a vacuum sealed with glass, so that visible light is emitted in the lower direction of the drawing. Is becoming A lens 46 composed of a converging fiber array is provided below the fluorescent writing head 41, and a visible light image is projected on the photosensitive member 1 on the exposure table 3.

Since the purpose of the present invention is to obtain a full-color image, the fluorescent writing head 41 is divided into three blocks of dot groups corresponding to the exposure of three colors of red, green and blue. In contrast, lenses 46 are individually provided.

The phosphor 45 used here has a light emission characteristic
From the point of view of life etc., the one whose peak wavelength is blue-green is used. Although it emits blue-green light when visually observed, since it contains red, green, and blue wavelength components and has high brightness, a latent image can be formed on the photosensitive member 1 at high speed. Then, as described above, a clear full-color image can be obtained on the transfer member 8 by pressure transfer after heat development.

In the case of the present embodiment, the photosensitive member 1 having an A4 width is used, and the number of dots of the fluorescent writing head 41 is 2550 dots for each color and has a resolution of 300 DPI.

Now, the fluorescent writing head 41 is used.
The sensitivity matching between the photosensitive member 1 and the photosensitive member 1 will be described.

As described above, an excellent color image can be recorded by combining the fluorescent writing head 41 and the photosensitive member 1, but the respective spectral characteristics (emission of red, green and blue light). Intensity and sensitivity to this light) do not always match. In particular, the photosensitive member 1 of the present invention has a unique property of low sensitivity to red, and it is necessary to consider the effect of this. Therefore, it is possible to obtain a color image having a better color balance by performing appropriate correction in this respect.

Various prescriptions for this purpose will be described below. In addition, in the present embodiment, five correction examples from the first to the fifth are shown as specific examples, but it is obvious that the present invention is not limited to this.

First, a first correction example will be described.

FIG. 3 is a schematic view of the fluorescent writing head 51. One fluorescent writing head 51 is red,
The structure is divided into three color exposure areas, green and blue.
The respective luminous dot groups are arranged in a zigzag pattern, and the luminous dot groups extend over the entire width direction (A4 width) of the photosensitive member. The feature of this example is the arrangement of each color, as shown in the figure, green,
The order is red and blue. What is important here is that the part corresponding to the red exposure always comes to the center.
A lens 52 is provided below the fluorescent writing head 51, but as a general optical characteristic of the lens 52, the central portion has a large amount of light and the amount of light gradually decreases toward the peripheral portion. In this example, this property is applied, and the arrangement of the red exposure portion is given the highest priority so that the red portion of the photosensitive member 1 having a low sensitivity has the largest light amount.
This can increase the red exposure amount.

Next, a second correction example will be described.

FIG. 4 is a partial plan view of another example of the fluorescent writing head 53, in which the exposure dot arrangement is divided into red, green and blue regions. In the figure, the number of exposure dots corresponding to red exposure is larger than that of exposure of colors other than red. In the case of this example, as can be seen from the drawing, the number of times of red exposure for exposing the same area of the photosensitive member is twice as large as that of exposure for other colors. This increases the red exposure amount. Of course, the number of times is not limited to twice, and for example, a light amount limiting element such as a color filter is used, or the fluorescent writing head 5 is used.
By appropriately controlling the anode voltage of No. 3 and its voltage application method, it is possible to perform optimum light amount correction according to the red photosensitivity characteristic of the photosensitive member.

Next, a third correction example will be described.

FIG. 5 is a schematic view showing another example of the fluorescent writing device 54, which mainly has one fluorescent writing head 55, a lens 56, and a strip-shaped area having three regions of red, green, and blue. It is composed of a color filter 57. In this example,
Exposure is performed three times to form one color image.
First, the color filter 57 is moved by a driving mechanism (not shown) so that the red region is inserted into the optical path. Then, while moving the photosensitive member 1, exposure for one image corresponding to red is performed. Next, the photosensitive member 1 is rewound to the original position, and the color filter 57 is moved to arrange the green region in the optical path. Then, while moving the photosensitive member 1, exposure for one image corresponding to green is performed. The photosensitive member 1 is rewound to the original position again, the color filter 57 is moved, and finally, exposure for one image corresponding to blue is performed. A full-color image is formed by the above steps.

At this time, at the time of exposure corresponding to red, the moving speed of the photosensitive member 1 is made slower than that at the exposure of other colors. Of course, the drive signal applied to the fluorescent writing head 55 is also controlled in synchronization with the moving speed. In other words, the exposure time for each color is not the same, and especially the exposure time for red is lengthened, and as a result, the exposure amount for red can be increased compared to other colors.

In the present embodiment, the color filter 57 is constituted by combining a plate-shaped dichroic filter, but of course, other than this, for example, a gelatin filter or the like may be used, and the shape thereof may be disk-shaped, tubular-shaped or the like. It can be in the form.

Further, in addition to the method of changing the moving speed of the photosensitive member 1 as described above, the same effect can be obtained by performing, for example, only red exposure twice (that is, a total of four exposures). You can Of course, the number of exposures is not limited to two, and more precise exposure amount control may be performed by combining the moving speed of the photosensitive member 1 and the number of exposures.

Next, a fourth correction example will be described.

This method relates to the dynamic driving of the fluorescent writing device and is characterized in that the driving duty corresponding to each color is different, and in particular, the driving duty of red exposure is larger than that of other colors.

As shown in the conventional example, the fluorescent writing device as in this example is usually driven dynamically. For example, FIG. 6 is a timing chart when the eight drive dots D1 to D8 are driven at a 1/8 duty. Such a dynamic driving method is generally used, and since the driving timing of each dot does not overlap, only one driver is required. In this example, the exposure is applied to green and blue.

On the other hand, in the case of red exposure, dynamic driving as shown in FIG. 7 is performed. As is clear from the figure, two dots are driven simultaneously for each of the dots D1 to D8, and the duty in this case is 1/4.
Although the number of drivers is doubled as compared with the above, the exposure amount is also doubled, so that a sufficient red exposure amount can be secured.

In the case of this example, of course, the number of times is not limited to twice, and as described above, for example, a light quantity limiting element such as a color filter is used, and the anode voltage of the fluorescent writing head and its voltage application method are appropriate. By controlling to 1, it is possible to perform optimum light amount correction according to the red photosensitivity characteristic of the photosensitive member.

Next, a fifth correction example will be described.

This example is characterized in that an auxiliary exposure device for correcting the exposure amount is provided in addition to the fluorescence writing device. In particular, a red light emitting element for supplementing red exposure is used as an auxiliary exposure device.

FIG. 8 is a schematic diagram of an exposure system including an auxiliary exposure device, which will be described below with reference to this figure. In the figure,
The fluorescent writing device 4 is the one described in the above embodiment. A print head 21 mainly including a red light emitting diode array (LED array) is provided in the vicinity of the fluorescent writing device 4, and cooperates with the fluorescent writing device 4 to expose the photosensitive member 1. It is configured. The print head 21 is almost the same as that generally used as an electrophotographic writing device, and its emission center wavelength is about 650 nm. Then, the fluorescent writing device 4 performs exposure for each color of red, green, and blue, and at the same time, by applying a red exposure signal to the print head 21 to drive it, the amount of red exposure can be increased.

In the above example, the print head is L
Although the ED array is used, the invention is not limited to this. Other than this, for example, an electroluminescence (EL) element, a liquid crystal shutter, a PLZT shutter, a scan exposure by a laser, and the like can be considered. However, in the case of this example, the LED array is used in consideration of the fact that the color of red is particularly supplemented and the advantage of the simple configuration.

With respect to the first to fifth correction examples described above,
In particular, we have described how to increase the red exposure.
Among these, as a phosphor used in a fluorescent writing device, a phosphor having a blue-green peak has been taken into consideration in consideration of its characteristics and the like. However, there are many types of phosphors, and it does not mean that they must be bluish green. In general, red-based phosphors are not often used because they are slightly inferior in terms of brightness, life, cost, etc., but considering the characteristics of the photosensitive member with low red sensitivity like this example, red-based phosphors You may select the fluorescent substance of.

Further, in the above-mentioned embodiment, since the red sensitivity of the photosensitive member is a particular problem, the correction of only the red exposure amount has been described, but of course the invention is not limited to this.
Similar corrections may be applied to other exposures (blue and green). In this case, it is effective to adjust in the direction of decreasing the exposure amount rather than the red exposure. By doing so, a color image having a better color balance can be obtained. Further, various forms of the fluorescent writing head that can be applied to the above embodiment can be considered. As described in JP-A-1-95073, dot pattern forms such as linear arrangement, zigzag arrangement, and diagonal arrangement, light ray directions such as front emission and rear emission, filament configuration, etc.
Both are applicable. Further, since the present invention is intended to form a color image, the exposure dots may be shared for each color, or each color may be made independent, or a plurality of independent fluorescent writing heads may be used.

[0051]

As described above, according to the present invention, by using a fluorescent writing device and a visible light-sensitive heat developing material, it is possible to obtain a high-speed, clear image at a small size and low cost. This has an effect that a printer can be configured.

Furthermore, red, green, and
By appropriately controlling the blue exposure amount, and particularly by performing red exposure that corrects the low red sensitivity that is a characteristic of the present heat-developable material, it is possible to obtain a high-quality image excellent in color balance. ..

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic diagram of a fluorescent writing device of the present invention.

FIG. 3 is a schematic diagram showing a first correction example of the present invention.

FIG. 4 is a schematic diagram showing a second correction example of the present invention.

FIG. 5 is a schematic diagram showing a third correction example of the present invention.

FIG. 6 is a timing chart showing an example of driving the fluorescent writing device of the present invention.

FIG. 7 is a timing chart showing an example of driving red exposure dots of the fluorescent writing device of the present invention.

FIG. 8 is a schematic diagram showing a fifth correction example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive member 2 Cartridge 3 Exposure stage 4, 54 Fluorescent writing device 5, 15 Conveying roller 6 Thermal developing device 7 Paper feed tray 8 Transfer member 9 Paper feeding device 10 Pressure transfer device 11 Upper roller 12 Middle roller 13 Lower roller 14 Separation roller 16 Paper Output Tray 17 Pinch Roller 18 Winding Shaft 19 Manual Feed Port 20 Gas Filter 21 Print Head 41, 51, 53, 55 Fluorescent Writing Head 42 Cathode 43 Control Electrode 44 Anode 45 Phosphor 46, 52, 56 Lens 57 Color filter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 1/23 103 C 9186-5C

Claims (6)

[Claims] 1. An electron emitted from a cathode is controlled by a control electrode to a heat-developable photosensitive member having microcapsules in which at least a photosensitive material and a coloring material are encapsulated on a support, and an anode portion. The color printer is characterized in that a color image is formed by irradiating a phosphor provided on the substrate with a fluorescent writing device that emits visible light containing at least red, green, and blue components. 2. A fluorescent writing device having a fluorescent writing head corresponding to each exposure of red, green and blue,
2. The fluorescent writing device according to claim 1, wherein the arrangement of each color is in the order of green, red, and blue. 3. A fluorescent writing device having a fluorescent writing head for red, green, and blue exposure, respectively.
2. The fluorescent writing apparatus according to claim 1, wherein the number of exposure dots of each color is not the same. 4. The color printer according to claim 1, wherein the fluorescent writing device is dynamically driven and the driving duties of red, green and blue exposures are not the same. 5. A fluorescent writing device equipped with a switchable filter for three colors of red, green, and blue is used to form a color image by performing at least three exposures corresponding to each color, and at the same time, for each color. The color printer according to claim 1, wherein the exposure times are not the same. 6. The color printer according to claim 1, further comprising an auxiliary exposure device different from the fluorescent writing device.