JPH021887A - Image recorder - Google Patents

Abstract

PURPOSE:To reduce fatigue in a photosensitive body even when image is successively exposed and to reduce adverse effect in image exposure by varying the time to set an image area signal according to each page in a series of recording papers. CONSTITUTION:When a control circuit 20 initiates exposure after setting the number of the papers on which the same images (original) are printed based on operator's instruction, it detects an exposure page according to the condition of a system; according to the size of the paper and data on the detected page, it then decides the data indicating the beginning and end of an image area, which is to be written in preset registers 21 and 22. The circuit 20 transmits a clear signal to F/F 23 to clear and also writes the data, which indicate the beginning and end of the image area, to the registers 21 and 22 at the timing of transmitting the clear signal. Counters 26 and 27 are reset in response to a SOS signal; clock from a circuit 24 is countered; in circuits 28 and 29, the counted value is compared with the data in the registers 21 and 22; when they coincide with each other, a coincidence signal is inputted to the terminals S and R of the F/F 23, respectively, thereby inputting an image area prescribing signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an image recording device N that defines an image area on a photoreceptor.

(Prior Art) Conventionally, such a device has been used in a laser printer, etc., which can expose one page of an image on a photoreceptor. As shown in Figure (a), the image 1 rear 12 for exposing the image onto the photoreceptor 11 was predefined in accordance with the paper 4 noise, paper edge blank length, and the like.

Then, in order to form an image on the photoreceptor 11, a laser 1 is used.
3, the reflected light 14 is detected by the polygon mirror 15, and the reflected LED light is detected by the detection means of SO8 (start opsen IJ-) 16, and as shown in FIG.
In accordance with b), based on the generation of the SO8 detection signal (SO3 signal), the image is exposed after a predetermined time from 5O8 (No. 3).
An image area defining signal (see FIG. 3 (cl)) defining the image area 1 is outputted to control the exposure of the image.

[Problem that y-Ming attempts to solve] However, in the above device, when recording many sheets of the same image, the gland 17 (third (See Figure (a)), a specific part of the photoconductor is always exposed to light, which causes fatigue of the photoconductor and adversely affects the exposure of images on subsequent pages, such as missing images due to poor charging properties. It had the disadvantage of being redundant. Particularly recently, with the miniaturization of printers, the use of small-diameter photoreceptors has increased, and the negative shadow tTj,l on images due to fatigue of the photoreceptor in the process direction has become a problem.

The present invention was developed in response to the above problem, and by continuous recording of the same image, even when images expressed in the process direction are exposed continuously, fatigue of the photoreceptor is reduced, thereby reducing the negative effects of image exposure. An object of the present invention is to provide an image recording device that can perform the following steps.

[Means and effects for solving the problem] In this Komei, for example, when the number of prints of the same image (original) is set based on an operator's instruction and exposure is started, the page marked “-J3 for exposure is detected. ：Ij Uru detection means, and according to each page detected by Moeki, the moeki base that is preset based on paper 1 noise, paper edge blank length, etc. (iii) a time setting means for varying and setting the time from the rise to the fall of the image area signal, the rise and fall of the image area signal that defines the image area from the generation of the reference signal that determines the exposure start timing of the same image; 1) Set the time to fall so that it varies according to each page, and set the exposure amount of the image in the process direction of the photoreceptor separately for each page within a range that does not substantially affect it. Even if the straight line in the direction of the substrate is the same image, the same location on the photoreceptor is blurred and the image is recorded.

[Example] An example of Komei Ki will be described in detail based on the drawings of FIGS. 1 and 2.

FIG. 1 is a block diagram showing the configuration of an image recording apparatus according to the present invention. In the figure, the control circuit 20 includes a CPU,
It is composed of ROM, RAM, etc., and depending on the paper size, it outputs the SO8 signal and the image area definition signal (see Figure 2).
d), data (to.

tl) and the falling edge (end) of the image quality area defining signal, and the determined data is set in the preset registers 21 and 22 at the output timing of the clear signal.
At the same time, the clear signal is output to the RS flip-flop (hereinafter referred to as rF/FJ) 23 which outputs the image area defining signal, and the clear signal is output to the F/F2.
Initialize 3. Note that the data that determines the rising and falling edges of the image area defining signal is stored in advance in the RA.
Mr? The information is stored in a table according to paper size, number of prints, etc.

The video clock generation circuit 24 receives the SO8 signal (see FIG.
The video clock is generated by modulating the clock from the optical oscillator 25 in synchronization with the counter 26.
27 counts by the video clock and resets the count by the SO8 signal.

The comparison matching circuits 28 and 29 are connected to the preset register 2.
When the data of 1.22 and the count data of counter 26.27 match, a match signal (Fig. 2 (b), (c),
(e), (f)) is output, and the above F/F23
is the above -f1 signal input to the input terminal S (Fig. 2(b)
, (e)) and input to the input terminal R. The image areas other than the image areas where images are written are reset to define the image areas.

Next, the operation of the above device will be explained.

First, when the number of prints of the same image (original) is set based on an operator's instruction and exposure is started, the control circuit 20 controls the system status (for example, the rotation of the photoreceptor, the
? The page in the above-mentioned exposure is detected by a scanner (ner scanning, etc.), and data indicating the beginning and end of the image area to be entered into the preset registers 21 and 22 is determined according to the paper size and the data of the detected page. In other words, the control circuit 20 controls the beginning of the image or area depending on whether the lowest bit 1- (LSB) of the data indicating each page of the number of prints is "O" or 111 I+. Decide whether to set it to t0 or 1.

Here, for example, when the LSB is 'O' (even number), t
If the data indicates o and the LSB is '1' (odd number),
Let this be data indicating tl. Note that in the initial state of exposure start, the LSB is 0'', so data indicating to is written in the preset register 21, and data indicating the above-mentioned to and tl are sequentially written in accordance with the number of prints.

Next, the control circuit 20 sends a clear signal to the F/F 23 to clear the F/F 23, and writes data indicating the beginning and end of the image area to the preset registers 21 and 22 at the sending timing of the clear signal. .

Next, the SO8 (not shown) detects a laser beam from a laser, and when the detection signal (SO3 signal) shown in FIG. 2(a) of the SO8 is shifted by R1, the counters 26 and 27 are reset, It counts the video clocks from 24 and outputs the values from 1 to 24 to the respective compare and match circuits 28 and 29. The comparison matching circuit 28 compares the data indicating the beginning of the image area written into the preset register 21 with the count value of the counter 26,
When the count value matches the data, a match signal is output to the input terminal S of the F/F 23. The F/F 23 is set by the coincidence signal and outputs a high-level image area definition signal from the output terminal Q (Fig. 2(d), (
(see l). Further, the comparison and coincidence circuit 29 compares the count value of the counter 27 with the data indicating the end of the picture Buddha area filled in the preset register 22, and when the count value matches the data, the F/F 23 A match signal is output to input terminal R. The F/F 23 is reset by the coincidence signal, and sets the image area definition signal outputted from the output terminal Q to a low level (Fig. 2(d), (
(see g)).

When the image area regulation signal is output, the irradiation area of the laser beam on the photoreceptor 30 is regulated by the image area regulation signal, and as shown in FIGS. 2(h) and (i),
Control is performed within an image area 31 defined for each page of the number of prints. That is, in the present invention, when 18B is an even number, as shown in FIG. 2(h), t has elapsed since the SO8 signal was generated.

Later, an image area 31 is set, and after a certain period of time, a line 32 based on the same image is exposed, and the LS
When B is an odd number, as shown in Figure 2(i), SO8
An image area 31 is set t1 after the signal is generated, and a reduction 32 of the same image is exposed after a certain period of time has elapsed. As a result, the line 32 on the photoreceptor 30
Since the exposure is controlled at different positions shifted from tl-to for each even and odd numbered pages, the same location in the process direction is not exposed continuously by the laser, reducing fatigue of the photoreceptor, and reducing the fatigue described above. It is possible to prevent the negative effects associated with Further, in the present invention, the exposure position in the process direction of the image is changed, for example, at 240 spi (
Even if the image area is shifted in the main scanning direction of the photoconductor by 1 spot during spot perinch, the change will be 25%.
．． 4/240 [mm], and even if the exposure position of the image is changed, image exposure is performed well, and problems such as poor exposure do not occur in practice.

In the embodiment, the exposure position of the image was changed using LSB data, but the present invention is not limited to this, and it is also possible to change the exposure position based on the upper bits according to the characteristics of the photoreceptor. Further, in the above embodiment, the exposure position of the image is changed depending on whether each page of the number of prints is an odd number or an even number, but the present invention is not limited to this. For example, the exposure position may be changed separately for each page, Of course, it is also possible to change the exposure position of a specific page. Furthermore, in the case of a synchronous printer that always starts exposure from the same position on the photoreceptor, problems may also arise with respect to both P exposures in the main scanning direction. In this case, the same effect as described above can be obtained by applying the image exposure control in the process direction of the photoreceptor described in the above embodiment and performing the image exposure control 20 in the main scanning direction of the photoreceptor depending on the page.

[Effects of the Invention] As explained above, in the present invention, since the time for defining the image area defining signal 4 can be changed depending on the number of pages to be printed, it is possible to change the time for defining the image area defining signal 4 depending on the number of pages to be printed. Even when images are continuously exposed, fatigue of the photoreceptor can be reduced, adverse effects on image exposure can be reduced, and good image exposure can be performed.

23...RS flip 70 tube, 24...Video clock 5 raw circuit, 25...Optical oscillator, 26.27...
- Counter, 28.29... Comparison - number circuit.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of an image recording apparatus according to the present invention, FIG. 2 is a diagram showing signals from each circuit shown in FIG. 1 and lines exposed on a photoreceptor, and FIG. The figure is a diagram for explaining a conventional device.

Claims (1)

[Scope of Claims] Generating a reference signal that determines an exposure start timing of an image, and controlling the exposure of the image by setting an image area signal that defines an image area in which the image is exposed based on the generation of the reference signal, An image recording apparatus that records the image, comprising: a detection means for detecting the number of recorded sheets of the same image; and a time setting means for changing the time for setting the image area signal according to each page of the detected number of recorded sheets. An image recording device comprising: exposing the image to different image areas defined for each page.