JPH11311845A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a fault caused by color slippage even in the case that a black line or the like is recorded by exposing three colors of blue, green and red in turn at a scanning and exposure time by putting the other exposure between some exposure and the next exposure among the plural exposure. SOLUTION: Light which is transmitted through a rotary color filter 11 from a light source system (white color light source) 10 and with which the input part of an optical fiber is irradiated is guided to a light modulation system (PLZT array) through the optical fiber and exposed at the prescribed position of a recording medium. The filter 11 is constituted so that the exposure other than the below mentioned B, G or R, for example, the exposure of three colors of BGR(blue, green and red) or the exposure of an ND filter can be put between the exposure of the blue color B and the next exposure of the green color G or the red color R while transmitted wavelength is successively changed. In the filter 11 constituted so as to realize such putting-in system exposure, three color of BGR is set as one unit and repeatedly arranged in an idetical pattern to it in plural times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming a color image on a recording medium using the same optical recording system.

[0002]

2. Description of the Related Art Conventionally, to form a color image,
It was common to use at least three printheads for red, green and blue exposure,
When a light modulating element such as a PLZT array print head is used as a white light source, a single print head can form a full-color image simply by replacing color filters in principle.

In particular, in the case of a PLZT array print head, a large cost reduction effect can be expected, and the optical recording system after the light transmission system can be reduced to 1/3, which is also useful for making the entire system compact. Was.

[0004] Incidentally, the control method of the PLZT element includes a method of controlling an optical output value of each optical fiber connected to each element, and a method of controlling a polarization time.
The former method of controlling the optical output value of each optical fiber is not only difficult to control, but also causes an increase in cost. On the other hand, the latter method of controlling the polarization time is also difficult as in the above, since thousands of unit elements are individually controlled.

Therefore, as a control method of the PLZT element which does not have the above-mentioned problem, a method of performing multiple exposure and bit-resolved multiple exposure for speeding up has been considered to be good. This is because the light emission time is decomposed into 2 ⁿ and 2 ⁿ types of gradations can be realized by repeating on / off n times.

[0006]

However, when performing 2 ⁿ exposure, when performing scanning exposure for speeding up, if a single light source attempts to complete the exposure in order for each color, a black line When exposing, etc., red while scanning,
Since green and blue are sequentially exposed, the emission timing of each color is always shifted, and there is a risk that a color shift may occur.

An object of the present invention is to provide an image forming apparatus which can solve the above-mentioned problem, and which can remarkably improve the problem of color misregistration even in the case of recording a black line in scanning exposure for speeding up. It is intended to provide.

[0008]

In order to achieve the above object, the present invention comprises at least a light source system, a light transmission system, a light modulation system, an imaging optical system, and color filters having different transmission wavelengths. By sequentially changing the transmission wavelength of the plurality of exposures in an image forming apparatus that performs multiple exposures on a recording medium that relatively scans and moves by the same optical recording system to form images of different colors. Among them, another exposure can be inserted between one exposure and the next exposure, and the color shift can be improved.

According to a second aspect of the present invention, the color filter is a rotating body, and the control of changing a recording color to be recorded on a recording medium can be easily performed, thereby enabling high-speed recording. It was configured as follows.

Further, the invention according to claim 3 is characterized in that the color filter can sequentially change each color of blue, green and red, and is configured so that a full-color image can be easily obtained.

Further, the invention according to claim 4 is characterized in that the color filter is a pattern of one unit of blue, green and red, and the same pattern is repeatedly arranged a plurality of times. It was designed to be effective for inserting other exposures between the exposure and the next exposure.

Further, the invention according to claim 5 is characterized in that the color filter has two or more of blue, green and red, respectively, wherein one color is exposed between one exposure and the next exposure. In addition to being effective for inserting other exposures, the configuration is such that high-speed recording and simple control are possible by optimizing the rotation speed and size of the filter according to the exposure time.

Further, the invention according to claim 6 is characterized in that the color filter has a neutral density filter (hereinafter referred to as an ND filter) in addition to a red, green and blue filter.
Gray and black characters and lines can be recorded without overlapping three colors of red, green and blue.

Further, the invention according to a seventh aspect is characterized in that the color filter has a light shielding means, and it is possible to block leaked light during a standby time (off state) at the time of color change. It was configured as follows.

Further, the invention according to claim 8 is characterized in that the plurality of exposures are bit-resolved multiple exposures, and multi-tone exposure can be realized within a time for exposing one line. It was configured as follows.

Further, the invention according to claim 9 is characterized in that, during the longest exposure of the bit-separated multiple exposure, exposure of another color is performed, so that a slight color shift is made inconspicuous. Configured.

Further, the invention according to claim 10 is as follows:
The recording medium is made of silver halide color paper, so that high-quality images can be formed at a low running cost.

[0018]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a schematic sectional view of an image printer to which the present invention is applied, FIG. 2 is a schematic perspective view of an enlarged optical recording system, FIG. 3 is a perspective view of a color filter portion, and FIG. Front view of the filter, FIG.
FIG. 6 is a front view of a color filter in which three colors of GR are arranged in two units with one unit of three colors. FIG.
Front view of the color filter arranged in the unit, FIG.
FIG. 8 is a front view of a color filter having an ND filter in addition to the three R colors, FIG. 8 is a front view of a color filter used for bit-resolved multiple exposure, and FIG. 9 is a schematic diagram of bit-resolved multiple exposure.

Image printer body 1 to which the present invention is applied
As shown in FIG. 1, image information captured by a scanner 5 is recorded by an optical recording system 6 on a recording medium (photographic paper) 4 which is a silver halide color photosensitive material pulled out from a photographic paper magazine 2 by a transport means 3. Then, the developing unit 7
, And is subjected to a developing process, cut into a predetermined size by a cutter 8 and discharged onto a discharge tray 9. Needless to say, the cutting may be performed before the sheet is conveyed to the developing unit 7.

As shown in FIG. 2, the optical recording system 6 transmits light K which is transmitted from a light source system (white light source) 10 through a rotary color filter 11 to an input unit 13 of a light transmission system (optical fiber) 12. Through an optical fiber 12 to a light modulation system (PLZT array) 14 to expose the recording medium 4 at a predetermined position.

The exposure is performed on the recording medium 4 conveyed in the direction of the arrow by conveying rollers 3a and 3b rotating in connection with a driving source (not shown).
Exposure of the color filter 4 and the color filter 11 is controlled according to image data R, G, and B according to instructions from the image output control unit 15 and the filter switching control unit 16. When the exposure process is completed, the recording medium 4 is conveyed to the developing unit 7 as described above, and an output image is obtained through a predetermined developing process.

The PLZT array 14 employed as the light modulation system employs a plurality of PLZT shutter elements arranged at 300 dpi in a single-row array. 4, which is effective in increasing the recording speed.

Although the recording medium 4 has been described as being in the form of a roll, it may be cut paper from the beginning of paper feeding. The transport means 3 for the recording medium 4 is not limited to the transport rollers 3a and 3b shown in FIGS. further,
The recording medium 4 may be fixed and the print head may move, or the recording medium and the PLZT array may move together.

The imaging optical system 17 of the PLZT array 14
Although a roof mirror lens array or the like may be used, the use of a cell hoc lens array has an advantage that it can contribute to the realization of miniaturization and cost reduction of the entire apparatus.

Although the recording operation has been described as an example of an array in which the PLZT shutter elements are arranged in a line, the recording on a recording medium can be performed even in an array in which a plurality of recording elements are arranged or a two-dimensional panel. By appropriately setting the timing with respect to the position and performing exposure control, a color image can be recorded.

Further, as another embodiment of the present invention, the same effect can be obtained even when performing image recording by combining a shutter array such as a liquid crystal shutter array.

As shown in FIG. 3, the color filter 11 arranges each color of blue (B), green (G), and red (R) at positions divided into three (every 120 °) on the disk. The center shaft 11a is connected to a drive source (not shown).

As shown in FIG. 3, the input portion 13 of the optical fiber 12 connected to each element of the PLZT array 14 passes through the mirror tunnel 10a from the light source system 10 and passes through the color filter 11 which rotates according to the color change timing. A predetermined applied voltage corresponding to the colored light is supplied. Thereby, the transmission wavelength can be selected. Thus, the light of the selected wavelength is applied to each element of the PLZT array 14 via the light transmission system (optical fiber) 12.

In this case, when the color filter 11 rotates and the color filter is switched, the boundary 1
Since 8 crosses the optical path, there is a disadvantage that two elements are simultaneously irradiated on each element of the PLZT array 14. In order to avoid this, the color filter 11 is provided with a light shielding means 19.
It has.

In the embodiment, the light shielding means 19 is a light shielding unit 1.
9a and a turntable having a transparent portion 19b.
During the time when the boundary 18 of the GR crosses the optical path, the light shielding portion 19a
This prevents the applied voltage from being supplied over the boundary (off state) so that light leakage during the standby time can be regulated.

The turntable constituting the light-shielding means 19 has its center axis 19c connected to a drive source (not shown), and the light-shielding portion 19a is inserted into the optical path at the timing when the boundary 18 of the color filter 11 crosses the optical path. Or they are being evacuated.

The color filter 11 changes the transmission wavelength sequentially, for example, between the exposure of blue (B) and the exposure of the next color, green (G) to red (R), to another exposure. For example, it is configured such that exposure of three colors of BGR or exposure of an ND filter can be inserted.

To realize the above-mentioned exposure insertion, for example,
In FIG. 5, three colors of BGR are defined as one unit (unit) u, and a plurality of (two units in the figure) are repeatedly arranged in the same pattern. In FIG. 6, BGR is set to 1 unit u,
Three units are arranged in the same pattern. Further, FIG.
In this example, an ND filter is provided in addition to the BGR filter.

Further, in FIG. 8, bits are decomposed and BGRs are arranged in three units u ₁ , u ₂ and u ₃ according to the length of the exposure time. In this case, when the maximum exposure time of the bit of the BGR of u ₁ and a, the exposure time of the bit of the BGR of u ₂ bits of each BGR of _{a / 2, u 3 a /} 4
It is good to arrange as follows.

The color filter 11 shown in FIGS. 5 and 6 includes another unit for inserting gray or black characters or lines between exposures of each color of BGR of one unit (unit) u. A unit (unit) u of BGR 1 to 3 colors can be inserted. Also, the one shown in FIG.
By inserting an ND filter without inserting the three colors of BGR between the exposures of each color of BGR, gray and black characters and lines can be recorded.

The color filter 11 shown in FIG.
Can be used for bit-resolved multiple exposure. That is, the time for exposing one line in the scanning exposure is predetermined by the scanning speed and the resolution. In order to realize multi-tone exposure within this fixed time, it can be said that bit-resolved multiple exposure is preferable.

The bit-resolved multiple exposure means that a light emission time of α × 2 ⁿ (α is a real number, n is an integer) is allocated in advance within a recording time per line, and the exposure is performed by a combination of n times of ON / OFF. (Decomposition into binary).

As described above, three bits from the bits of the BGR having a long exposure time are assigned to the color filter 11 in advance, and in the case of a short exposure time, exposure is performed using a filter having a long exposure time, thereby reducing the rotation speed of the filter. Recording can be performed without performing control. For example,
Taking FIG. 8 as an example, in the case of 12-bit control, if the exposure of each color is Bm, Gm, and Rm (m is a recording bit), the following is obtained.

That is, R ₁₁ → G ₁₁ → B ₁₁ (u ₁ ) → R ₁₀ →
G ₁₀ → B ₁₀ (u ₂ ) → R ₉ → G ₉ → B ₉ (u ₃ ) →
_{R 8, R 7, R 6} ... R 0 → G 8, G 7, G 6 ... G 0 → B
_{8, B 7, B 6 ...} B 0 (u 1)

For example, taking as an example the light emission of 12 times, when the recording time per line is set to 2800 μsec and the light source is about 600 nW, each of the light emission time (α) of the 12 times of red exposure is performed. Is: α = 0.1 × 2 ⁰ = 0.1 μsec 0.1 × 2 ¹ = 0.2 μsec 0.1 × 22 ² = 0.4 μsec 0.1 × 2 ³ = 0.8 μsec 0.1 × 2 ⁴ = 1.6 μsec 0.1 × 2 ⁵ = 3.2 μsec 0.1 × 2 ⁶ = 6.4 μsec 0.1 × 2 ⁷ = 12.8 μsec 0.1 × 2 ⁸ = 25.6 μsec 0.1 × 2 ⁹ = 51.2 μsec 0.1 × 2 ¹⁰ = 102.4 μsec 0.1 × 2 ¹¹ = 204.8 μsec. By setting ON / OFF of the time set in this way according to the image signal value, 2 ^{1 2} = 40
96 gradations can be realized (see FIG. 9).

By performing the above method, the emission time is long and the color shift is conspicuous.
, The color shift can be prevented, and the recording can be performed without controlling the rotation speed of the filter.

The size and rotation speed of the color filter 11 are determined by the maximum exposure time of each color. That is, when the outer diameter of the color filter 11 is small, the rotation speed can be reduced, and when the outer diameter of the color filter 11 is large and there is a margin, the rotation speed can be increased.

Further, by changing (controlling) the rotation speed in accordance with the exposure time, it is possible to shorten the waiting time for waiting for the color filter switching (the time when the boundary of the BGR crosses the optical path). Become like

When changing (controlling) the rotation speed of the color filter 11, since a sudden change causes rotation unevenness, it is important to control the rotation so as to make a gradual change in speed. For this purpose, it is preferable to switch the order of exposure for each line. Specifically, 2 ^0-2
Taking the exposure of ^{1 1} of 12 times as an example, gradually increasing the exposure time to the first line 2 ⁰ → 2 ^{1 1.} The exposure time is gradually reduced from the second line 2 ^{1 1 to} 2 ⁰ . The exposure time is gradually increased from the third line 2 ^{0 to} 2 ¹¹ . In this case, the rotation speed of the color filter 11 becomes slow.

The color filter 11 is arranged such that the colors of blue (B), green (G) and red (R) are arranged on the same disk, and the recording color can be sequentially changed by rotating the disk. However, this is effective in that the control of changing the recording color can be easily performed, but it is not always necessary to limit the change.

[0046]

As described above, the image forming apparatus according to the present invention includes at least a light source system, a light transmission system, a light modulation system, an imaging optical system, and color filters having different transmission wavelengths.
In the image forming apparatus, by sequentially changing the transmission wavelength of the color filter to perform exposure a plurality of times on a recording medium relatively scanned and moved by the same optical recording system to form images of different colors, Is characterized in that another exposure can be inserted between one exposure and the next exposure among blue exposure, so that blue (B), green (G), red (R) Even when a black line or the like is recorded by sequentially exposing the three colors, it is possible to remarkably improve the problem of color misregistration.

Further, the invention according to claim 2 is characterized in that the color filter is a rotating body, so that it is possible to easily control the change of the recording color to be recorded on the recording medium and to perform high-speed recording. It has an excellent effect that it becomes possible.

Further, the invention according to claim 3 is characterized in that the color filter is capable of sequentially changing each color of blue, green and red, and has an excellent effect that a full-color image can be easily obtained. To play.

Furthermore, the invention according to claim 4 is characterized in that the color filters are arranged in a plurality of units with one unit of three colors of blue, green and red. This is an excellent effect that it is effective to insert another exposure between the exposure.

Further, the invention according to claim 5 is characterized in that the color filter has at least two blue, green and red color filters, respectively. In addition, it is effective to insert other exposures, and has the excellent effect that high-speed recording and simple control become possible by optimizing the rotation speed and size of the filter according to the exposure time. is there.

Further, the invention according to claim 6 is characterized in that the color filter has an ND filter in addition to the blue, green and red filters, so that gray and black characters and lines are displayed in red, Green, blue 3
This provides an excellent effect that recording can be performed without overlapping colors.

Furthermore, the invention according to claim 7 is characterized in that the color filter also has a light shielding means, so that it is possible to block the leakage light during the standby time at the time of color change. It has the effect that it has.

Furthermore, the invention according to claim 8 is characterized in that the plurality of exposures are bit-resolved multiple exposures, so that multi-tone exposure is performed within a time for exposing one line. This is an excellent effect that can be realized.

Further, the invention according to the ninth aspect is characterized in that exposure of another color is performed during the longest exposure of the bit separation multiple exposure, so that even if a color shift occurs, it is conspicuous. This has an excellent effect of disappearing.

Further, the invention according to claim 10 is as follows:
Since the recording medium is made of silver halide color paper, high quality images can be formed at low running cost.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an image printer to which the present invention is applied.

FIG. 2 is an enlarged schematic perspective view of an optical recording system.

FIG. 3 is a perspective view of a color filter unit.

FIG. 4 is a front view of a color filter provided with a BGR.

FIG. 5 is a front view of a color filter in which two units of three colors of BGR are arranged as one unit.

FIG. 6 is a front view of a color filter in which three units of BGR are arranged as three units.

FIG. 7 is a front view of a color filter having an ND filter in addition to the three colors of BGR.

FIG. 8 is a front view of a color filter used for bit-resolved multiple exposure.

FIG. 9 is a schematic diagram of bit-resolved multiple exposure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image printer main body 2 Printing paper magazine 3 Conveying means 3a, 3b, drive roller 4 Recording medium (silver halide color photosensitive material) 5 Scanner 6 Recording system 7 Development processing unit 8 Cutter 9 Discharge tray 10 Light source system (white light source) DESCRIPTION OF SYMBOLS 11 Color filter 12 Optical transmission system (optical fiber) 13 Input part of optical fiber 14 Optical modulation system (PLZT shutter array) 15 Image output control part 16 Filter switching control part 17 Imaging optical system (Cell hoc lens array) 18 BGR boundary 19 Light shielding means 19a Light shielding part 19b Transparent part 19c Central axis of turntable

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsuyoshi Haraguchi 1 Sakuracho, Hino-shi, Tokyo Inside Konica Corporation

Claims (10)

[Claims] At least a light source system, a light transmission system, a light modulation system, an imaging optical system, and a color filter having different transmission wavelengths are provided. In an image forming apparatus that forms images of different colors by performing a plurality of exposures on a recording medium that moves and scans in a moving manner, among the plurality of exposures, another exposure is performed between one exposure and the next exposure. An image forming apparatus characterized in that exposure can be inserted. 2. The image forming apparatus according to claim 1, wherein the color filter is a rotating body. 3. The color filter according to claim 1, wherein the color filters are blue, green,
3. The image forming apparatus according to claim 1, wherein each of the red colors can be sequentially changed. 4. The color filter according to claim 1, wherein the color filters are blue, green,
4. A pattern in which red is defined as one unit pattern, and the same pattern is repeatedly arranged a plurality of times.
2. The image forming apparatus according to claim 1, wherein: 5. The color filter according to claim 4, wherein the color filters are blue, green,
2. The image display device according to claim 1, wherein each of the plurality of red colors has two or more red colors.
4. The image forming apparatus according to any one of 1. to 3. 6. The color filter according to claim 6, wherein the color filters are blue, green,
6. The method according to claim 1, further comprising a neutral density filter in addition to the red filter.
An image forming apparatus according to claim 1. 7. The image forming apparatus according to claim 1, wherein the color filter has a light shielding unit. 8. The image forming apparatus according to claim 1, wherein the plurality of exposures are bit-separated multiple exposures. 9. The exposure of another color is performed during the longest exposure of the bit separation multiple exposure.
An image forming apparatus according to claim 1. 10. The image forming apparatus according to claim 1, wherein the recording medium is made of silver halide color paper.