JPH09277500A - Image forming method and its apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a toner saving rate by simple constitution by generating (n) types of mask data by a mask-operating video signal with each of n-th mask data and parallel-serial-converting the mask data. SOLUTION: A video signal 112 which was synchronized with the basic video clock of a four-fold video clock 111 and inputted into AND gates 103-106 is processed to obtain a logical product with mask data 113 of a set toner saving rate. The video clock 111 is counted by a counter 101, the bit 0 and bit 1 of the counter output are processed by the AND gate 102 to obtain a logical product, and logic '1' is outputted at a time to four clocks to generate a load signal 114. By a parallel serial converter 107, with timing to make the load signal 114 active, each output signal 4 of the gates 103-106 is loaded, a parallel input value is converted into a serial value synchronously with the four fold video clock 111 to be outputted as a mask video signal 115.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner saving system in a laser beam printer.

[0002]

2. Description of the Related Art Conventionally, as a toner saving method in a laser beam printer, as shown in FIG. 1, there is a method of thinning out an actual toner output by taking a logical product of a video signal and a video clock and outputting the logical product. .

[0003]

However, in the above-mentioned conventional example, the toner saving rate is 50% at maximum. Also,
Since the position where the video signal is masked is the same for all lines, there is a problem that vertical stripes are likely to appear and the print quality is poor. The present invention has been made in view of the above conventional example, and provides an image forming method and apparatus capable of adjusting a toner saving rate with a simple configuration and capable of forming an image with high print quality. With the goal.

[0004]

In order to achieve the above object, an image forming method and apparatus according to the present invention have the following arrangement. That is, the video signal is converted into the nth mask data (n = 1,
2, ...) Performs a mask operation for each of the mask data to generate n pieces of mask data, and n generated in the generation step.
And a conversion step of performing parallel-serial conversion on the individual mask data.

According to another invention, a video signal is masked with each of the nth mask data (n = 1, 2, ...)
And a conversion unit for performing parallel-serial conversion on the n mask data generated by the generation unit.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] FIG. 2 is a drawing that best represents the features of the first embodiment. In the figure, 101 is a counter, 102 to 106 are AND gates, 107 is a parallel-serial converter, 111 is a quadruple video clock having a frequency four times that of the basic video clock (not shown), and 112 is an input. A video signal, 113 is mask data, 114 is a load signal, and 115 is a toner-saving masked video signal sent to a printer engine (not shown).

Next, the processing operation in the above configuration will be described. First, the CPU (not shown) sets the toner saving rate in a register (not shown) or the like, and outputs the mask data 113 therefrom. For example, when the saving rate is 0% (meaning that the toner is not saved), the mask data = "1".
111b "(b means that it is a binary number), 25
% Is "1110b", 50% is "1010b", 75% is "
1000b ".

The video signal 112 synchronized with the basic video clock of the quadruple video clock 111 is input to the AND gates 103, 104, 105 and 106, and the AND gates take a logical product with the mask data 113. In addition, the quadruple video clock 111 is supplied to the counter 101.
Counting with, the bit 0 and bit 1 of the counter output
Is ANDed by the AND gate 102 to generate a load signal 114 which outputs a logic "1" once every four clocks.

In the parallel-serial converter 107, when the load signal 114 becomes active, the AN
Load 4 bits of each output signal of D-gates 103, 104, 105, 106. And 4 times video clock 1
In synchronization with 11, the parallel input values are converted into serial values and output as a masked video signal 115. An image is formed by a printer engine (not shown) based on the masked video signal 115. An example of this image formation is shown in FIGS. 3, 4, and 5.

Here, the saving rate is 75% in FIG. 3 and 40 in FIG.
%, And FIG. 5 shows the case of 25%. FIG. 6 shows an example of a formed image when the toner is not saved, and FIG. 7 shows an example of a formed image according to the conventional embodiment. With such a very simple configuration, it is possible to efficiently adjust the toner saving rate. [Second Embodiment] FIG. 8 is a drawing best showing the features of the second embodiment. It should be noted that, in comparison with FIG. 2, the same processing units are given the same reference numerals. Therefore, different parts will be described.

In FIG. 8, 108 is a line counter,
Reference numeral 109 is a mask data generation circuit, 116 is saving rate data, 117 is a horizontal synchronizing signal, and others are the same as those in the first embodiment (FIG. 2). Next, the operation in the above configuration will be described. First, the line counter 108 counts the horizontal synchronizing signal 117, and 00b → 01b → 10b.
The scanning lines are counted as →→ 11b → 00b → .... Here, "b" means that the last digit is a binary number.

A CPU (not shown) sets a toner saving rate in an internal register (not shown) and outputs a saving rate data signal 116. FIG. 9 shows the relationship between the mask data 113 output from the mask data generation circuit 109 corresponding to the saving rate 116 and the line count (output of 108). With reference to FIG. 9, for example, when the saving rate is 0%, the saving rate data = 00b, 25% 01b, 50%
10b and 75% to 11b.

Here, a case where the saving rate is 75% will be described as an example. At this time (the saving rate is 75%), the mask data generation circuit 109 has a line count of 00.
When b, the mask data is 0001b and 01b is 0100.
b, 10b outputs 0010b and 11b outputs 1000b. In the first embodiment, the masking position is the same for every line, but in the present embodiment, it is changed for each line. Other operations are
This is the same as the first embodiment.

Print samples output according to this embodiment are shown in FIGS. Note that the saving rate is 75% in FIG. 10, 50% in FIG. 1, and 25% in FIG. However, these samples have been expanded for clarity. As can be seen from these samples, the print quality can be improved when the toner is saved.

The mask data generation circuit may be realized by a random logic circuit or may be constructed based on a control circuit having a CPU and a sequencer built therein. In addition,
The present invention may be applied to a system including a plurality of devices or an apparatus including a single device. As described above, according to the present embodiment, it is possible to print at a predetermined toner saving rate with a very simple configuration.

Further, there is an effect that the printing quality is improved when the toner is saved.

[0017]

As described above, according to the present invention, it is possible to adjust the toner saving rate with a simple structure and form an image with high print quality.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a conventional example.

FIG. 2 is a configuration diagram showing a first embodiment.

FIG. 3 is a diagram of a print sample according to the first embodiment.

FIG. 4 is a diagram of a print sample according to the first embodiment.

FIG. 5 is a diagram of a print sample according to the embodiment of the first invention.

FIG. 6 is a diagram of a print sample when toner is not saved.

FIG. 7 is a diagram of a print sample in a conventional example.

FIG. 8 is a configuration diagram showing a second embodiment.

FIG. 9 is a diagram showing an input / output processing operation of a mask data generation circuit.

FIG. 10 is a diagram of a print sample according to the second embodiment.

FIG. 11 is a diagram of a print sample according to the embodiment of the second invention.

FIG. 12 is a diagram of a print sample according to the embodiment of the second invention.

[Explanation of symbols]

101 counter 102, 103, 104, 105, 106 AND gate 107 parallel-serial converter 108 line counter 109 mask video generation circuit 111 4 times video clock 112 video signal 113 mask data 114 load signal 115 masked video signal 116 saving rate data 117 Horizontal sync signal

Claims (14)

[Claims] 1. The video signal is converted into the nth mask data (n = 1,
2, ...) and performs a mask operation to generate n pieces of mask data, and a conversion step of performing parallel-serial conversion on the n pieces of mask data generated in the generation step. A characteristic image forming method. 2. The image forming method according to claim 1, further comprising an image forming step of forming an image based on the data converted and output in the converting step. 3. The conversion step performs parallel-serial conversion of the n pieces of mask data generated in the generation step in synchronization with a clock that is n times the fundamental frequency of the video signal. The image forming method according to claim 1. 4. The image forming method according to claim 1, wherein each of the n-th mask data (n = 1, 2, ...) Designates a toner saving rate. 5. The image forming according to claim 1, wherein the mask calculation is a logical product calculation of each of the video signal and the nth mask data (n = 1, 2, ...). Method. 6. The n-th mask data (n = 1, 2, ...) Each changes according to the count number of the horizontal synchronizing signal corresponding to the video signal. 1. The image forming method described in 1. 7. The image forming method according to claim 2, wherein in the image forming step, the data converted and output in the converting step is sent to a laser beam printer to form an image. 8. The n-th mask data (n = 1,
2, ...) and performs a mask operation to generate n pieces of mask data, and a conversion means for performing parallel-serial conversion on the n pieces of mask data generated by the generation means. A characteristic image forming apparatus. 9. The image forming apparatus according to claim 8, further comprising an image forming unit that forms an image based on the data converted and output by the converting unit. 10. The conversion means performs parallel-serial conversion of the n pieces of mask data generated by the generation means in synchronization with a clock that is n times the fundamental frequency of the video signal. The image forming apparatus according to claim 8. 11. The nth mask data (n = 1,2, ...)
9. The image forming apparatus according to claim 8, wherein each of the items specifies a toner saving rate. 12. The mask operation comprises a video signal and an n-th signal.
9. The image forming apparatus according to claim 8, which is a logical product operation with each of the mask data (n = 1, 2, ...). 13. The nth mask data (n = 1,2, ...)
9. The image forming apparatus according to claim 8, wherein each of the numbers changes based on the count number of the horizontal synchronization signal corresponding to the video signal. 14. The image forming apparatus according to claim 9, wherein the image forming unit is a laser beam printer.