JPS59212825A - Automatic adjusting device for exposure amount of copying machine - Google Patents

Abstract

PURPOSE:To set a proper exposure and printing speed for any kind of original having different light transmittivity and to stabilize an automatic adjustment of the quantity of light by providing a light diffusion and transmission type filter to either of a light source and a detection sensor for the quantity of light transmission. CONSTITUTION:An original A from a table 7 passes through carrying-in rollers 9, 10, 17, and 18 and is exposed to an exposure cylinder 1 while superposed upon photosensitive paper B. The detection sensor 13 for the quantity of light transmission detects the quantity of light on the original A with the light from the light source 14 through light diffusion and transmission type filters 15 and 16. Then, a sensor 12 detects the original being carried in and the sensor 13 detects the light transmittivity of the original; and the output of a circuit 21 is inputted to respective circuits for amplification 24, peak voltage detection 25, holding 26, timing 27, control signal conversion 28, and motor speed control 29 successively to control a motor M.4, controlling the moving speed of the superposed body of the original A and photosensitive paper B on the drum 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic exposure amount adjustment device for a copying machine, which adjusts the exposure amount of photosensitive paper that is superimposed and brought into close contact with the original document by knowing the amount of light transmitted through the original document being carried in. .

In general, an automatic exposure amount adjustment device detects and measures the amount of light transmitted through an incoming document using an arbitrary light beam, and calculates the light transmittance of the document by calculating the ratio of this detection signal and a reference voltage. 1, the light intensity of the exposure lamp or the exposure printing time (speed) is adjusted using a control signal calculated by calculating this light transmittance at a required ratio. In other words, since the amount of exposure has a correlation between the luminous intensity of the exposure lamp and the fog light printing time, if either of them is adjusted, the amount of exposure can be adjusted by W4.

FIG. 1 shows a custom line diagram of the light transmittance and exposure/printing speed of various originals fed into a conventional automatic exposure adjustment device. In the figure, for example, the text of various types of manuscripts such as general paper A1, No. 101 tracing vapor A2, Japanese paper for tights A, 3, piece 1'lJ] low film A42-, transparent resin film A5, etc. The blank area where figure bonds are not listed (
Using A with the best light transmittance (indicated by peak voltage (G)) and the respective originals MA l , A 2... The relationship between the exposure and printing speed (rn/k]), which is adjusted so that the background part of the photosensitive paper that has been printed and developed has a constant density, is clearly not uniform, and the heave diagram X is a non-linear curve. In other words, from the general purpose A1 which is the main material of the bulb, the light transmittance is 90.
For example, in order to ensure that the transparent film A5, which is coated with mylar film, is coated with oil, it is necessary to prepare a complicated (ii + glazing structure). It is necessary to do it, and the Iij defeat of 7 is complicated, and it becomes a high 1st case, and the general work is difficult.

In view of the above points, the present invention effectively replaces the conventional technology with a seven-book, 1,114-base base, and moreover, a copying machine that is cheaply printed at the time and guarantees full reputation. (Tsuki's self-envy) and provides a gong-tuning ritual device.

According to the present invention, such purpose is achieved by at least
1 or 9 expansion cut transmission type filter on Isuno L7J on the new transmission detection sensor side! By increasing I, the coupled δ is generated.

Next, I will explain in detail one example of the present invention based on one song.

Fig. 2 shows a schematic diagram of an automatic swivel adjustment device for a first copying machine according to the present invention. roller 9
and is inserted into the hill by the driven roller lO.

This original document A is then conveyed in the direction of the exposure and printing drum l via the conveyance driving roller 17 and the driven roller 18. At this time, the photosensitive paper B is conveyed separately from the original A (11) by the driving roller 19S and the driven roller 20 for conveying the review paper, and then brought together and brought into close contact with the original A and 11 (by the conveyor belt 8) to the exposure printing drum. Next, the exposure lamp 3 built in the exposure and printing drum l completes the printing on the photosensitive paper B. It is suspended between a plurality of drive rollers 6A and moves in the direction of the arrow.

Note that the exposure and printing drum 1 is rotated by contact friction with the conveyor belt 8. If printing is completed 1-, original A
The photosensitive paper B is then discharged from the fog light printing drum 1. The reflector plate 2 is housed in a Fukko printing drum, and the exposure lamp 3
Support the back.

In addition, the light source 14 is a driven roller 101rllll for carrying the document.
Furthermore, a light transmission amount detecting sensor, in this embodiment a photo sensor 13, is installed on each of the main driving rollers 9, facing the light source 14. Note that this light source 149iij and photo+
On the side of the sensor 13, there are seven filters for diffusing and transmitting light 11] and 101 filters for this embodiment.

The light diffusivity of the cellulose structure of the filters 15 and 16 is a tradeoff of light transmittance, and for example, the structure film A5 shown in FIG.
The light transmittance detection circuit 21 corresponds to the output voltage of the photosensor 13 that detects the light emitted from the light source 14 when the document A is brought in, for example. The light transmittance of the original is calculated by comparing the reference voltage with the original pre-transmission detection code.

The document carry-in detection sensor 12 is provided close to the document carry drive roller 9, and detects that the document A has been carried in, and sends a signal to the document carry-in detection circuit 22.

The timing circuit 23 detects the detection 48 of the document loading detection circuit 22.
Due to the issue, the imported document A is further detected by the photo sensor 13.
The light transmitting vehicle detection circuit 21 is activated after a margin time (timing) is taken until reaching the point. Due to this operation, the light transmission wheel detection circuit 21 continuously detects and measures the light transmittance to the document during a predetermined time period during which the 7JLt document A passes the photosensor 13. The amplifier circuit 24 performs all the essential amplification and passes it on to the peak voltage detection circuit 25.

By the way, in manuscript A, we need to detect the light transmittance of a part of the manuscript in order to write the necessary characters -f, 7, figures, etc. It is difficult to judge that the light transmittance of the light transmittance is accurately determined.

At this moment, the peak voltage detection circuit 25 detects the voltage corresponding to the best light transmittance among the light transmittances of the document A that are continuously detected. The hold circuit 26 holds this voltage.

Next, when the Song end of the original 8a A finishes passing over the photo sensor 12, the timing circuit 27 takes the required timing and transfers the held peak voltage to the control signal conversion circuit 2.
Send to 8. The control signal conversion circuit 28 converts the peak voltage into
converting it into a speed control signal for the drive motor, and controlling the speed of the drive motor 4 fully automatically via the motor speed control circuit 29;
Adjust the exposure amount.

Next, FIG. 3 shows a characteristic diagram of one embodiment of the present invention shown in FIG. In the figure, since filters 15 and 16 made by Tracing Vapor No. 101 are used, each original Al, A
The relationship between the rate of change of peak voltage (■), which is the maximum value of the light transmittance through 2, A3, A4, and A5, and the exposure printing speed (m/h) is clearly an iα line-like line. It is shown in diagram Y. Therefore, each tih original'(iJ A l ,
A2, according to -C exposure printing speed (m/h)
holds true proportionally, so various manuscripts Al, A2゜...
Regardless of its type (i!J), the automatic exposure adjustment is stable.

Next, FIG. 4 shows a characteristic diagram of another embodiment of the present invention.

As shown in the figure, a light diffusion transmitting type filter, in this example, a milky-white polypropylene thin plate filter, is placed on the nine side 14 side and the photosensor 13 side, respectively, similar to the tracing paper filters 15 and 16 in Figure 2. With this equipment, various manuscripts At, A2. A3, A4, A
The relationship between the change in the peak voltage (V) indicating the light transmittance through 5 and the exposure printing speed (m/11) is as shown in No. 3171.
and wandering, is shown in the almost area line diagram 2, and each one is cool i)
, tAi, A2, . . . , stable eye movement exposure amount adjustment can be easily achieved regardless of the type.

As explained above, according to the present invention, 7. L By installing a light diffusion transmission filter on either the light source side or the light transmission amount detection sensor side, it is possible to achieve an appropriate level despite the multi-pole and multi-quality properties with different light transmittances. When the exposure printing speed is set, the structure is extremely simple, and the exposure amount adjustment can be done easily and easily.

[Brief explanation of drawings]

Figure 1 is a % gonad diagram of the light transmittance and exposure printing speed of various originals sent to the conventional automatic exposure level Le J refinishing machine, and Figure 2 is the automatic exposure diagram of a copying machine to which the invention is applied. FIG. 3 is a characteristic diagram of an example M of the present invention shown in FIG. 2, and FIG. 4 is a characteristic diagram of another embodiment of the present invention. 12.13: Photo sensor, 14: Light source, 21: Light transmittance detection circuit, 25: Peak voltage detection circuit, A, AI, A
2. A3, A4, A5: Original, B: Photosensitive paper. Patent applicant Copia Co., Ltd. No. 1 1,1 41st Vision

Claims (1)

[Claims] ■) It has a light source that emits light onto the document being carried in, and a transmitted light amount detection sensor that is installed opposite to this light and detects the amount of light that has passed through the FA document, and the detection signal of this transmitted light value detection sensor In a device that automatically adjusts the amount of exposure to the photosensitive paper that overlaps with the original transported to the exposure and printing drum that has a built-in exposure light source, light is diffused to at least the light source at or the light transmission amount detection sensor side. An automatic exposure amount adjustment device for a copying machine characterized by being equipped with a transmission type filter.