JPH03251865A - Multicolor recorder - Google Patents

Abstract

PURPOSE:To prevent the extreme deterioration of the color reproducibility of a multicolor picture by controlling the amount of undercolor removal according to the amount of a recording agent detected by means of a detecting means. CONSTITUTION:R, G, and B signals 1-3 from a host computer are logarithmically transformed to printing color picture signals 12-14, respectively, by a color converting circuit 4. The black extracting circuit 5 of a UCR processing circuit 20 generates a BK signal 15 by the use of the Y, M, and C signals. A black removing circuit 6 removes the BK signal from the Y, M, and C signals to obtain the Y, M, and C signals. A UCR control switching circuit 9 switches in such a manner that the amount of the extracted BK signal 15 becomes small according to the toner presence/absence level of a BK toner detecting signal 10, and the amounts of Y, M, and C of a circuit 7 become large. A UCA processing circuit 7 generates the Y, M, and C signals after adding shadow balance correction to the signals from the circuit 6. A masking process is performed in a masking process circuit 8, so that the Y, M, and C signals having satisfactory color reproducibilities corresponding to the color picture signals are generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multicolor recording device such as a laser beam printer or an LED printer that forms and records a multicolor image.

[Prior Art] Conventionally, this type of multicolor recording device, for example, a laser beam printer, uses four colors of ink: Y, M, C, and Bk.
A multicolor image is formed and recorded by performing OCR processing and masking processing.

Basically, as shown in FIG. 8, the laser beam printer 53 receives code data sent from a printer engine 51 that records dot data on a photosensitive drum based on dot data and an external host computer 54, and prints data based on this code data. generate page information consisting of dot data,
It is composed of a printer controller 52 that sequentially sends dot data to a printer engine 51.

Further, the host computer 54 loads one application software from a floppy disk 55 having various kinds of application software, and starts the program.

For example, when performing color image processing using the application software, the user can create and store a large amount of multicolor information.

FIG. 9 is a block diagram showing a signal processing circuit of the printer controller 52 shown in the eighth figure.

The R signal 1, G signal 2, and B signal 3, which are color image signals from the host computer 54, are manually input, and the color image signals are converted into M signal 1, which is a color image signal for printing, by the color conversion means 4.
3. Convert and output the C signal 14 and Y signal 12, and use the black extraction circuit 5 from the previous Y signal 12, M signal 13, and C signal 14.
generates a Bk signal 15, a black removal circuit 6 removes black components from the Y signal 12, M signal 13, and C signal 14, a UCA processing circuit 7 corrects the shadow balance, and a masking processing circuit 8 According to Y, M, C,
The Bk signal is converted into Y, M, C, and Bk signals with good color reproducibility, and a switching control circuit (not shown) sequentially switches and reads out the Y, M, C, and Bk signals, and outputs them to a laser driver (not shown).

The conversion formulas of the color conversion circuit 4, black extraction circuit 5, and black removal circuit 6 are shown below.

Range O, 0 (no 1nk) ・4.0 (fu
ll 1nk), the color conversion circuit; cyan(u)
=1.0-red(u)magenta(u)=1.0
-green(u) u;useryellow(u
)=1.0J1ue(u) Black extraction circuit; black
(u) =BG (MIN (cyan (u),
magenta (u), yellow (u) ))
BG; black generation constant male removal circuit; cyan (d) = 1.0-RedT
(1,0-MAX (0,0cyan(u)-@bl
ack(u)l)magenta(d)=1.0-Gr
nT(1,0-MAX(0,0゜magenta (u
) -K”black (u) l)yellow (
d) =1.0-BluT(1,0-MAX fO,0
゜yellow(u)-K”black(u)))Re
dT, GrnT, BluT; transfer function; constant d; device [Problem to be solved by the invention] However, in the above conventional example, processing for forming a multicolor image was performed based on input signals; Y, M
, C, Bk color ink is insufficient, U
There was a problem in that the balance of Y, M, C, and Bk signals after CR processing was lost, and color reproducibility was extremely deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multicolor recording apparatus that can solve the above-mentioned problems and prevent extreme deterioration of color reproducibility of multicolor images.

[Means for Solving the Problems] In order to achieve such an object, the present invention includes a detection means for detecting the amount of recording agent, and an amount of undercolor removed according to the amount of recording agent detected by the detection means. 2. Undercolor control means for controlling
) Detects the amount of recording material.

The present invention also provides a detection means for detecting the amount of a recording agent, and a detection method that detects when there is no rhinoceros recording agent as a result of detection by the detection means.
2) Undercolor removal/addition control means for controlling the amount of undercolor removal or addition of undercolor; and 2) detecting the amount of recording material.

Furthermore, the present invention includes a detection means for detecting the amount of recording agent;
2) recording switching means for recording in monochrome with another recording material when there is no recording material as a result of detection by the detection means;
In addition, the present invention provides a detection means for detecting the amount of recording material, and a detecting means for detecting the amount of recording material. 2) A recording control means for recording in monochrome or not recording with any recording agent; and 2) detecting the amount of recording agent.

[Function] In the present invention, the amount of recording material is detected by the detection means, and the undercolor removal amount is controlled by the undercolor control means in accordance with the amount of recording material detected by the detection means.

Further, in the present invention, the amount of recording material is detected by the detection means, and if there is no black recording material as a result of the detection by the detection means, the amount of undercolor removal is controlled by the undercolor removal addition control means; Controls the amount of undercolor added.

Further, the amount of the recording agent is detected by the detection means, and if the detection means detects that there is no recording agent, the recording switching means performs recording in monochrome using another recording agent.

Furthermore, the amount of the recording agent is detected by the detection means, and if the detection means detects that there is no recording agent other than the black recording agent, the recording control means determines whether to record in monochrome using another recording agent or Do not record with any recording medium.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the invention.

In the figure, 4 is a color conversion circuit, in which R signal 1, G signal 2, which is a color image signal from a host computer (not shown),
The B signal 3 is logarithmically converted into a Y signal 12, an M signal 13, and a C signal 14, which are color image signals for printing. The density of the YMC signal from the color conversion circuit 4 is shown in FIG. 2(a).

1.0 is 100% concentration and 0.0 is 0% concentration. 5 is a black extraction circuit, which extracts Bk from the YMC signal from the color conversion circuit 4.
The signal 15 is generated. Y from black extraction circuit 5
, M.C.

The density of the Bk signal is shown in FIG. 2(b). A black removal circuit 6 removes the Bk signal from the MMC signal from the color conversion circuit 4 to produce a YMC signal. The densities of the Y, M, C, and Bk signals from the black removal circuit 6 are shown in FIG. 2(c).

7 is an OCA processing circuit which adds a shadow balance correction amount to the MMC signal from the black removal circuit 6 to produce a YMC signal. The densities of the Y, M, C, and Bk signals from the UCA processing circuit 7 are shown in FIG. 2(d). 16 in Figure 2(d).
Reference numeral 17 indicates a signal for correction addition. 8 is a masking processing circuit which performs masking processing on the MMC signal from the UCA processing circuit 7 to produce an MMC signal with good color reproducibility in accordance with a color image signal.
It generates a signal. Reference numeral 9 denotes a UCR control switching circuit, which switches the amount of the Bk signal 15 extracted by the black extraction circuit 5 to a smaller amount depending on the toner presence/absence level of the toner detection signal 10 at 8, and increases the amount of the MMC signal of the UCA processing circuit 7 (
It is something that can be switched.

FIG. 3 is a flowchart showing the processing procedure by the OCR control switching circuit 9.

At step SL, Bk toner signal detection is checked.

(1) If the result of checking in step S1 is that there is no toner, the process moves to step S2, and in step S2 it is determined whether the level of the no-toner signal is rlJ.

(a) As a result of the determination in step S2, if the level of the toner-free signal is not "1", the process moves to step S6, and in step S6, OCR processing is performed using conversion positive;
In step S7, UCA processing based on conversion (2), that is, shadow balance processing is performed. And step Sl
At step 1, it is determined whether the data has ended or not. If the result of the determination is that the data has ended, the process ends; on the other hand, if the data has not ended, the process returns to step S1, and thereafter the data ends. Repeat the above steps until.

(b) As a result of the determination in step S2, if the level of the toner no signal is "1", the process moves to step S6, and in step S6, UCR processing is performed by conversion ■;
In step S7, UCA processing is performed using conversion (2), and the process moves to step Sll.

(2) If the result of checking in step S1 is that there is no toner, the process moves to step S3, and in step S3, a check is made to detect the non-signal detection of toners other than Bk.

(1) As a result of checking in step 83, if no toner signal other than Bk is detected, the process moves to step S8, in which OCR processing is performed using conversion I, and in step S9, UCR processing is performed by conversion processing. I do.

(ii) As a result of checking in step S3, if a non-Bk toner signal is detected, the process moves to step SIO, where it is determined that there is no toner error, and the process ends.

The correction coefficients of the black extraction circuit 5 in the OCR control switching circuit 9 are shown in FIG. 4, and the correction coefficients of the UCA processing circuit 7 in the UCR control switching circuit 9 are shown in FIG.

As explained above, UC depends on the level of toner presence based on the Bk toner detection signal and non-Bk toner detection signal.
By increasing or decreasing the amount of R, Y, M,
It is now possible to form a multicolor image without significantly disrupting the balance between C and Bk and without deteriorating the color reproducibility.

mastication FIG. 6 shows another embodiment of the invention.

In comparison with the first embodiment, this embodiment differs in the processing when there is no toner other than Bk. That is, in the example, B
The OCR processing amount is switched depending on the presence/absence level of k1-ner, and Y, M, and CBk signals with good color reproducibility are output, and Bk
In other embodiments, a forced print switching circuit 18 is provided, and a non-Bk toner detection signal causes a forced print mode signal to be issued even when non-Bk toner is absent. When No. 19 is in the forced printing mode, image formation is performed by monochrome printing.

FIG. 7 is a flowchart showing the processing procedure by the forced print switching circuit 18.

In step S20, it is checked whether or not the forced printing mode is set using the forced printing mode signal 19, and as a result of checking,
If it is not in forced print mode, the process ends.

On the other hand, if the result of checking in step S20 is that it is the forced print mode, the process moves to step S21. In step S21, as a result of checking the detection of toner signals other than Bk, if toner other than Bk is present, the process is terminated.

On the other hand, if the result of checking in step s21 is that there is no toner other than Bk, the process moves to step S22, where the signal is forcibly switched to the Bk signal to perform monochrome density conversion in the forced printing mode. Monochrome density is D・(Y+M+C)/(Y□U1M□8+
C□X). Then, in step S23, monochrome one-time conversion processing is performed using the conversion table shown in Table 1.

(Margins below) Table 1 Then, in step S24, it is determined whether or not the data has been completed. If the result of the determination is that the data has not been completed, the process continues from step S20 to step S2 until the data is completed.
Repeat step 4.

As explained above, since the UCR amount is increased or decreased depending on the toner presence/absence level determined by the Bk toner detection signal, the balance between Y, M, C, and Bk signals for color reproduction is not extremely disrupted, and toners other than Bk are Even in the case of no color, monochrome image formation can be substituted, and multicolor images can be formed without extreme deterioration of color reproducibility.

〔Effect of the invention〕

As explained above, according to the present invention, since it is configured as described above, a multicolor image can be formed without extreme deterioration of color reproducibility.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram explaining the image processing procedure in this embodiment, FIG. 3 is a flowchart showing the processing procedure by the UCR control switching circuit 9, and FIG. FIG. 5 is an explanatory diagram explaining correction of OCR processing in this embodiment. FIG. 5 is an explanatory diagram explaining correction of UCA processing in one embodiment. FIG. 6 is a block diagram showing another embodiment of the present invention. , FIG. 7 is a flowchart showing the processing procedure by the forced character switching circuit 18, FIG. 8 is a block diagram showing the basic configuration of a laser beam printer, and FIG. 9 is a block diagram showing a conventional example. 12.3... R, G, B signals, 4... Color conversion circuit, 5... Black extraction processing circuit, 6... Black removal processing circuit, 7... UCA processing circuit, 8... - Masking processing circuit, 9... LICR control switching circuit, 10... Bk) toner detection signal, 11... Toner detection signal other than Bk, 12 to 15... Y, M, C, Bk signal, 20 ...O
CR processing circuit. Figure 2 (C) (d) O 1,0 MIN (Y, M, C) JL! l! Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1) A detection means for detecting the amount of recording material, and an undercolor control means for controlling the amount of undercolor removed according to the amount of recording material detected by the detection means. Features a multi-color recording device. 2) a detection means for detecting the amount of recording material; and an undercolor removal addition for controlling the amount of undercolor removal or the amount of undercolor addition when there is no black recording material as detected by the detection means; A multicolor recording device characterized by comprising a control means. 3) A multi-color device comprising: a detection means for detecting the amount of recording agent; and a recording switching means for recording in monochrome using another recording agent when the detection means detects that there is no recording agent. Recording device. 4) A detection means for detecting the amount of recording material, and if the detection result by the detection means shows that there is no recording material other than black recording material, either print in monochrome with another recording material, or record in monochrome with any recording material. A multicolor recording device comprising a recording control means that does not record.