JPH0361940A - color image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color image forming apparatus for recording color image information on the surface of a photosensitive recording medium having a plurality of photosensitive wavelength ranges for producing a color image.

[Prior Art and Problems to be Solved] In recent years, various color image forming apparatuses have been known that record color image information on the surface of a photosensitive recording medium compatible with color images. In particular, with the progress of digitalization of image information, devices using semiconductor lasers, light emitting diodes (LEDs), and the like as information light have also been put into practical use.

By the way, currently the semiconductor laser is 780 to 830
It can only be put to practical use in a specific wavelength range, such as 1550 nm (CD players, laser printers, etc.) or 1550 nm (general communications, etc.). In addition, the practical wavelength range of LED is 650
The wavelength range that can be put to practical use is also limited, such as nm, 750 nm, or 840 nm. Therefore, in order to record color image information on a photosensitive recording medium using information light in these wavelength ranges, it is necessary to develop materials for the recording medium that have photosensitivity suitable for these wavelength ranges.

However, for example, some photosensitive recording media such as silver halide photographic films and photosensitive microcapsule sheets (see JP-A-58-88739, U.S. Patent No. 4,399,209, etc.) contain the semiconductor laser and the like. Some sensitivities do not match. For example, in the case of a silver halide photographic film, its spectral sensitivity is in the short wavelength region of 400 to 700 nm, so the above-mentioned semiconductor laser etc. cannot be used as it is. There are also special silver halide photographic films that have sensitivity in the infrared region (such as those made by Kodak), but these films have lower sensitivity in the infrared region than in the shorter wavelength region, so they cannot be exposed to light. A large amount of light is required, resulting in high energy costs. Furthermore, the above photosensitive microcapsule sheet 4
Semiconductor lasers cannot be used because they have spectral sensitivity in the short wavelength range of 00 to 700 nm. Even if semiconductor lasers were to be developed that could be used in photosensitive recording media having spectral sensitivity in these specific wavelength regions, there were problems such as high energy costs due to the short wavelengths.

On the other hand, there is also a device that records images by using a cathode ray tube (CRT) as information light.
By coating the R7 surface with a fluorescent material that emits light of a wavelength that matches the spectral sensitivity of the photosensitive recording medium, matching of the information light and the sensitive wavelength distribution of the photosensitive recording medium can be easily achieved. However, according to this method, when the electron beam output is increased, it is difficult to narrow down the beam spot diameter, so it is difficult to obtain high brightness, and there are quality problems such as printing outlines being unclear.

The present invention has been made in order to solve the above-mentioned problems, and is a color image capable of recording color images at high output on a photosensitive recording medium surface having a plurality of unique wavelength ranges for producing color images. A forming device is provided.

Another object of the present invention is to provide a color image forming apparatus that can realize gradation images. As a result, color image quality can be maintained and improved, and at the same time, energy costs for recording information can be reduced and the size of the apparatus can be reduced.

[Means for Solving the Problem] In order to achieve this object, the printing device of the present invention exposes the surface of a photosensitive recording medium having a plurality of photosensitive wavelength ranges to light based on color image information in order to produce a color image. a light emitting device that emits light based on the color image information; a photoelectric conversion device that converts the light emitted by the light emitting device into photoelectrons; and a secondary electron emitted by the photoelectrons converted by the photoelectric conversion device. and a photoelectron multiplier for multiplying the number of secondary electrons; a secondary electron accelerating means for accelerating the secondary electrons multiplied by the photoelectron multiplying means; and a fluorescent means for emitting light of a wavelength matching each of the photosensitive wavelength ranges of the photosensitive recording medium upon incidence of secondary electrons, so that the light of the wavelength emitted by the fluorescent means is irradiated onto the surface of the photosensitive recording medium. It consists of

Furthermore, the secondary electron multiplication factor control means is configured to individually control the multiplication factor of the secondary electrons incident on the fluorescent means.

[Function] According to the color image forming apparatus of the present invention having the above configuration, when light is emitted by the light emitting means based on color image information, this light is photoelectrically converted into photoelectrons by the photoelectric conversion means, and further photoelectrons are multiplied. At the same time as the secondary electrons are emitted, the number of secondary electrons is multiplied by the doubling means, and then the electron speed of the secondary electrons is accelerated by the secondary electron accelerating means, and the secondary electrons are incident on the surface of the fluorescent element, which is the fluorescent means. . On this fluorescent element surface, there are a plurality of types of fluorescent substances having spectral sensitivity characteristics corresponding to each of the sensitive wavelength ranges of the photosensitive recording medium, for example, a fluorescent substance that emits red light for red image information, A fluorescent material that emits green light is coated for green image information, and a fluorescent material that emits blue light is coated for blue image information. The photoelectron multiplier is separated, and the electron current value to the fluorescent element is controlled by controlling the number of secondary electrons incident on each fluorescent material for each color component of image information. , the fluorescent element, which is excited to emit light by the incident energy of the secondary electrons, has its emission brightness controlled by the electron current value, so that the light is irradiated onto the surface of the photosensitive recording medium;
Gradation image information is exposed and recorded on the surface of the medium.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the overall configuration of this device. In this device, light emitted from a light emitting element 1 such as a semiconductor laser is deflected within an angle θ range by an optical deflection system 2 such as a polycon mirror or a carbano mirror, and the light is photoelectrically converted and amplified via an imaging optical system 3. The light is input to system 4. The light emitted by the photoelectric conversion and amplification system 4 is configured to be scanned in the width direction of the photosensitive recording medium 5 that is conveyed in a fixed direction.

The photosensitive recording medium 5 used here includes photosensitive microcapsules encapsulating a cyan dye precursor, photosensitive microcapsules encapsulating a magenta dye precursor, and photosensitive microcapsules encapsulating a yellow dye precursor. It is assumed that the coating is uniformly distributed and applied to the surface of the base sheet.

In addition, its photosensitive wavelength is 650 nm for the cyan capsule.
Magenta capsule is 550nm, yellow capsule is 45nm
It is set to 0 nm. As shown in FIG. 1, the structure of the photoelectric conversion amplification system 4 includes a photoelectric conversion multiplier element 41 in order from the light incident side.
, a fluorescent plate 42, and an optical lens 43 are arranged side by side at a small distance from each other. The charge conversion multiplier element 41 has a photoelectric converter 41a on the light incident side that converts the energy of the incident light into photoelectrons, and a photoelectric converter 41a on the light output side that converts the photoelectrons obtained by the charge converter 41a into secondary electrons. A photomultiplier 41b that converts and multiplies the number of secondary electrons is arranged. As the photoelectric conversion substance used for the photoelectric conversion body 41a, for example, if the light emitted from the light emitting element 1 is in the visible light range, Sb-, -Na-Ca, etc.
Examples of materials in the near-infrared region include Ag-0-Cs. Further, the photomultiplier 41b is an aggregate 10 of fine through holes 103 called channels, as shown in FIG.
1, a secondary electron emitting material layer 103a is formed on the inner wall surface of each channel. The photoelectrons guided into each channel collide with the secondary electron emitting material layer 103a to emit secondary electrons, and the secondary electrons further collide with the secondary electron emitting material layer 103a to emit secondary electrons. The number of secondary electrons multiplies. The incident surface side (charging converter 41a side) of the photoelectric conversion multiplier element 41 is connected to a variable voltage power source 44, while the output surface side (photomultiplier 41b side) is grounded, and the variable voltage power source By changing the voltage value applied by the photoelectric conversion multiplier 44, the number of secondary electrons emitted from the photoelectric conversion multiplier 41 can be multiplied by several hundred thousand to several million times.

FIG. 3 shows typical characteristics of the secondary electron multiplication factor showing the relationship between the applied voltage and the number of secondary electrons (gain). This photoelectric conversion multiplier element 41 is generally referred to as a "microchannel plate." On the other hand, the fluorescent plate 42
A fluorescent substance is coated on the surface of the transparent substrate 42a (secondary electron incident surface side). Three types of fluorescent substances are used to coat the fluorescent plate 42, and their emission wavelengths match the sensitivity wavelengths of the cyan capsule, magenta capsule, and yellow capsule of the photosensitive recording medium 5.

That is, a fluorescent substance that emits red light (coloring wavelength 650 nm) corresponds to the cyan capsule, a fluorescent substance that emits green light (coloring wavelength 550 nm) corresponds to the magenta capsule, and a blue light (coloring wavelength 550 nm) corresponds to the yellow capsule. A fluorescent substance that emits color (coloring wavelength: 450 nm) is used. Each fluorescent substance (
The arrangement of the phosphor cells (phosphor cells) is as shown in FIG. A conceivable example is one arranged in stripes as shown in Fig. 5. Corresponding to the arrangement of the phosphor cells in this manner, electrodes attached to separate and independent photomultiplier means are arranged for each type of phosphor cell, and the electrodes are attached to the phosphor cell. When the light cells are arranged in stripes as shown in Fig. 5, as shown in Fig. 6, and when the phosphor cells are arranged in a delta shape as shown in Fig. 4. is constructed as shown in FIG. In this case, as shown in FIG. 4, the exposure spot shape 102 of the light emitting element 1 corresponds to a plurality of channel aggregates 101, and each channel aggregate 10
1 corresponds to each phosphor cell. A variable voltage power supply is connected to the electrode attached to the photoelectron multiplier, and a variable voltage power supply 115 is connected to the R phosphor, and a variable voltage power supply 11 is connected to the G phosphor.
6, and a variable voltage power supply 117 is connected to the B phosphor. By adjusting the power supply voltage based on the color information of the image information, the value of the incident electron current to the phosphor cell is controlled.

Further, as the optical lens 43, a short-focus rod lens array (trade name: "Selfoc lens") or the like is used whose focal point is exactly on the surface of the photosensitive recording medium 5.

In the color image forming apparatus configured in this way,
Light with image information emitted from the light emitting element 1 passes through an optical deflection system 2 and an imaging optical system 3 to a photoelectric conversion multiplication system 4.
When the light is incident on the photoelectric conversion element 41, the light is first converted into photoelectrons by the photoelectric conversion body 41a of the photoelectric conversion multiplication element 41.

Then, the number of electrons (secondary electron number) of the photoelectrons is multiplied by the photoelectron multiplier 41b to hundreds of thousands to millions of times as described above, and the photoelectrons are irradiated onto predetermined phosphor cells of the phosphor plate 42. be done. The light emitted from the phosphor cell irradiated with secondary electrons is irradiated onto a predetermined position on the surface of the photosensitive recording medium 5 via the optical lens 43. In this case, the light emitting element 1 emits red, green, and blue color information at the same time.
Although each G-B phosphor cell can be made to emit light at the same time, the photoelectron multiplication factor control means is separated for each type of phosphor cell for control based on the gradation data of the color information of the image information. is used. Color gradation image information is recorded by exposing a desired light irradiation position on the surface of the recording medium. This photosensitive recording medium is used to develop a visible color image on the surface of the developing paper by overlaying it with a desired developing paper and developing it under pressure.

In this embodiment, a semiconductor laser is used as a light emitting element for emitting image information light, but the invention is of course not limited to this; for example, an LED array, an EL array, etc. may be used.

It goes without saying that the photosensitive recording medium can also be applied to various types of color-compatible recording media, such as silver salt photographic films, in addition to the photosensitive capsule sheet described above.

Furthermore, the R phosphor cell, G phosphor cell, and B
The phosphor cells may be arranged in a polygonal (for example, triangular) shape. This eliminates the gaps between each phosphor cell, further improving image quality.

[Effects of the Invention] As is clear from the detailed description above, the image forming apparatus of the present invention photoelectrically converts the color image information light emitted from the light emitting means into photoelectrons, and further converts the photoelectrons into secondary electrons. At the same time, the photoelectrons are multiplied, thereby making the surface of the phosphor element emit light. Furthermore, it is a photoelectron multiplication method that can control the incident electron current value for each type of phosphor and control the gradation of the luminance of the phosphor. By configuring the attached electrode of the multiplication means, the light emitted from the light emitting means simultaneously irradiates charging conversion surfaces corresponding to multiple types of phosphors, and by controlling the photoelectron multiplication means, the color components of image information are By irradiating the surface of the photosensitive recording medium with emitted light based on gradation information, a markedly faster printing speed can be achieved compared to emitting light from a single type of phosphor and irradiating the surface of the photosensitive recording medium. A suitable tonal image recording is achieved. Furthermore, since the emission wavelength matches the photosensitivity of each color forming element of the photosensitive recording medium, printing energy is efficiently applied to the exposure of the surface of the photosensitive recording medium, improving energy efficiency.

Furthermore, since there is no need to use a short-wavelength semiconductor laser or the like, the device cost can be reduced and the device can be made more compact.

[Brief explanation of drawings]

1 to 7 show embodiments embodying the present invention. FIG. 1 is a schematic configuration diagram of an optical amplification system, which is the main part of the present invention, and FIG. 2 is a schematic diagram of an optical amplification system to which the present invention is applied. FIG. 3 is a gain characteristic diagram of a microchannel plate, FIG. 4 is a schematic explanatory diagram showing the correspondence between the microchannel plate and the phosphor cell surface, and FIG. 2 is another example of the arrangement of phosphor cells. FIGS. 6 and 7 are diagrams showing examples of the arrangement of electrodes serving as electron accelerating means. In the figure, 1 is a light emitting element, 4 is a light conversion and amplification system, 5 is a photosensitive recording medium, 41 is a photoelectric conversion multiplier, 41a is a photoelectric converter,
41b is a photomultiplier, 42 is a fluorescent plate, and 43 is an optical lens.

Claims (1)

[Scope of Claims] 1. A color image forming apparatus that exposes a surface of a photosensitive recording medium having a plurality of photosensitive wavelength ranges to light based on color image information to produce a color image, the apparatus comprising: A luminescent means for emitting light;
photoelectric conversion means for converting light emitted by the light emitting means into photoelectrons; photoelectron multiplication means for emitting secondary electrons and multiplying the number of secondary electrons by the photoelectrons converted by the photoelectric conversion means; the photoelectron multiplication factor control means that individually controls the multiplication factor of the secondary electrons amplified by the photoelectron multiplication factor control means; and the secondary electron acceleration that accelerates the secondary electrons multiplied by the photoelectron multiplication factor control means. means, and a fluorescent means for emitting light having a wavelength matching each of the photosensitive wavelength ranges of the photosensitive recording medium upon incidence of secondary electrons accelerated by the secondary electron accelerating means, the wavelength being emitted by the fluorescent means. A color image forming apparatus characterized in that the color image forming apparatus is configured such that light is irradiated onto the surface of the photosensitive recording medium. 2. The photosensitive recording medium expresses a full-color image, and the fluorescent means has fluorescent cells that emit red light, green light, and blue light arranged regularly on the fluorescent surface. The color image forming apparatus according to claim 1, characterized in that: 3. The light emitting means emits light in the shape of an exposure spot, in which one set each includes one red phosphor cell, one green phosphor cell, and one blue phosphor cell, or a set of a plurality of red phosphor cells. 2. A color image forming apparatus according to claim 1, wherein said photoelectron multiplication factor control means is configured to individually control the number of electrons incident on each set of phosphor cells. 4. The color image forming apparatus according to claim 2, wherein the fluorescent means includes fluorescent cells that emit red light, green light, and blue light and are arranged in a delta shape on a fluorescent surface. 5. The color image forming apparatus according to claim 2, wherein said fluorescent means has fluorescent cells that emit red light, green light, and blue light arranged in stripes on a fluorescent surface. 6. The photosensitive recording medium has photosensitive microcapsules containing a cyan dye precursor, photosensitive microcapsules containing a magenta dye precursor, and photosensitive microcapsules containing a yellow dye precursor uniformly dispersed and coated on the surface of the base sheet. The color image forming apparatus according to claim 1, characterized in that: