JPS6026364A - 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 The present invention relates to an equipment for preserving original photographs of night photographs and the like. Adjust the volume VRi, etc. in the operation unit as shown in the figure, and then set the original light lamp LA1 as shown in Figure 2.
It was common practice to alternating the lighting voltage to obtain the appropriate image depth. However, in this conventional method, there are many cases in which several sheets of transfer paper are wasted before achieving proper performance, and the disadvantage is that more transfer paper is used than necessary.

The present invention has been developed to eliminate this drawback of the conventional method.At the same time, the reflected light from the original surface is detected by an electrometer or the potential of the photoconductor; The objective is to determine the degree of doping depending on the output level of the forging process and to control the voltage of the raw material W'r light lamp or the forging bias appropriately to obtain a very accurate υ degree image.

FIG. 3 shows an embodiment of the present invention. In the present invention, a photo sensor PH1 is provided in front of the in-mirror lens element M to detect the intensity of reflected light from the glass PL. D is a photosensitive drum, L is a document L"r light lamp, and its detection circuit is shown in FIG.
i] L, gain reading with operational amplifier 6 L T A D
The microcomputer 7 with a built-in converter inputs the input to the AD1 power of the microcomputer 7 according to the input level of the person D1 and the AD2 power level determined by the preparation volume 5.
;:J is output, and by integrating and inputting this to operational amplifier B, the output level of operational amplifier 6 is made to have a pulse width of J['iJ, and is output, and high voltage transformer 8
9 is a transformer that performs full-wave rectification on the secondary side and an operational amplifier 11 (which controls the AC zero cross pulse. 1 interrupt>;: Input by J child (), and by the interrupt processing caused by it, the input of AJ is included in the fifth program and the hand/M image bias is controlled.

766 flag (indicated by FG) to explain the 255 diagram.

The relationship with the sequence is shown in Figure 8. When the copy button is pressed, the main motor starts rotating, removes the drum, and
When the pre-rotation for cleaning is completed, the optical system starts moving forward and notifies the leading edge of the document.When there is an input from the sensor S in the middle of forward movement (Step 1), the time until the leading edge of the image reaches the developing operation is 0NTO counter. Start incrementing Step 2) 0NTO counter (Ag value) Measures the time from when the leading edge of the document is exposed to when the latent image is developed.Before starting development, there must be toner on the drum. AD2 to the preset value FF to prevent
(Step 0).

During this time, ADi is sampled and added to the value of Σ1 (Step 3), and after the above time has elapsed, F
When G is set (step 4), the value of Σ1 is set to 0NT
Divide by O to calculate the average value of ADI and set copy adjustment volume 5 (
Step 5) Calculate the H level pulse width control value T in PWM determined by the value of N as shown in FIG. 6 of routine a. . CNTO, CNTl, CNT2 are INT
0 is incremented for each input pulse In Figure 6, the value of H divided by 60 is 256L.
Since it is SB, the minimum O1 is 510, and this is 3 [IL
This is because if the data is divided in SB units, it can be divided into 18 parts. Therefore, by controlling the pulse width output to the 61 port in Fig. 4 for each value of N←N÷60, it is possible to develop as shown in Fig. 9. The zero development bias output component varies from -50 to -6 as shown in FIG. 10 depending on the development bias control voltage W shown in FIG.
In order to control this vB, the pulse width output from the 01 output port of the microphone is controlled.

The control j flowchart is shown in FIGS. 6 and 7. FIG. 7 shows a timer internal interrupt program that starts when the power is turned on, and then interrupts due to time-up.

By the way, in the middle of the time from when the image front edge signal from sensor S is input to when development starts, the counter CNT
2 starts. CNTl and CNT2 are the 8th and 12th
As shown in the figure, it serves to distinguish the sampling areas for calculating and determining the bias voltage, and the image area where the bias H7lJMari1 voltage is controlled by ■ is 2J1.
Figure 2 shows the 1st area (r) and the area in front of it (n-
1) or a value (2) calculated from the average value of the input data from the light detection sensor 1 in FIG. Here, the bias control voltage ■n is not limited to sampling only the control area (l), but also the bias control voltage
Or, based on data including sampling up to the later area (7L + 1), it is revealed that the present bias is controlled for changes in the concentration of travel between areas,
This is because the purpose is to provide resistance. The bias output is determined by averaging Σ1 for CNT 1 (step 5) and averaging Σ2 for CNT 2 (step 6).

By the way, since the photosensitive drum is a 0PC drum and has a negative primary charge, increasing the developing bias control voltage to the negative side will decrease the amount of development, resulting in a thin copied image. Therefore, as shown in FIG. 9, as the value of N increases, that is, as the density of the original becomes thinner, the negative value of the development pi)' DC component is decreased and the amount of development is increased. Control is performed to improve regeneration and, conversely, to eliminate fog in the copied image by increasing the development bias/f bus DC component for documents with high density such as newspapers.

As shown in FIG. 11, the volume 5 shown in FIG. 4 adjusts the DC component of the developing bias in order to obtain a proper copy image when the EV characteristic of the drum changes from one curve to two curves due to drum deterioration. This is a means for appropriate correction.

Note that in the present invention, the development bias is controlled by dividing the document scanning period based on the time from the input signal from the document leading edge detection sensor until the leading edge of the image is developed, and calculating the sampling data. The method is not limited to this, but for example, it may be possible to divide the scanning section by other suitable predetermined scanning based on time 1i or 2, or to use a copying machine with variable magnification capability, where the scanning speed of the optical system differs depending on the magnification. Therefore, control such as dividing and shifting the scanning section based on a predetermined scanning pressure section becomes effective. It is also possible to measure the potential on the photosensitive drum after being exposed to light and control it by performing the above-mentioned calculations. According to the present invention, it is possible to perform the above-mentioned calculations to control the electric potential on the photosensitive drum. It is possible to obtain duplicate images without overlapping images for dark originals such as images, which eliminates the hassle of adjusting the conventional Ω-circumferential lever, etc., and eliminates the wastage of transfer paper due to copy mistakes, resulting in an efficient copying function. is realized.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the operation section of a copying machine, Fig. 2 is a conventional density adjustment circuit diagram, Fig. 6 is an explanatory diagram of an optical system, Fig. 4 is a circuit diagram that realizes the original invention, and Fig. 50 to 7 Fig. 8 is a sequence timing chart, Fig. 9 is a relationship between calculated values and developing bias, and Fig. 10 is a flowchart of Fig.
The figure shows the relationship between the Inkuri bias control q1 voltage and the developing bias.
Figure 11 is a diagram of E y characteristics of the drum, and diagram ε312 is a diagram of the relationship between the bias control voltage and the original fl"'4 m4 degree sampling area, and 1 in the diagram is a photo sensor. Applicant: Canon Co., Ltd. 1 elephant bias f; l Cao Kan Denpe L15 [1/] Drum E-V publication + [Raw Ef: amount, Musset-

Claims (2)

[Claims] (1) It has a means for detecting the original 11.5 shading and a means for optimally controlling the retention forming process using the original 11.5 shading detection signal ~ 1 above.
The iIiJ control means performs first zangling on the detection means multiple times from a signal corresponding to the edge of the original image to judge and control the shading, and performs a second zangling again before the end of scanning to perform control. 8131 sampling processing and second sampling processing are executed in parallel. (2) At the first vertex, the second sampling is performed by a program interrupt with a series of pulses.
An image control device that generates a ν image. /−'−−1'−'