JPS58200230A - Automatic exposure adjustment 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 measures the density of a document in advance in a copying machine, and
The present invention relates to an automatic exposure amount adjustment device that automatically determines the exposure amount based on D1w@.

Conventionally, in JP-A-54-2134 and JP-A-54-62836, a method of reading the original Ijk degree t- is proposed for automatic exposure adjustment of copy idA, but the i deviation also requires a receiver placed at the top. at--Vc cut off the density of the passing document every moment5. This is because the detection signal is used to adjust the amount of exposure of the original to the photoreceptor.

When looking at the entire area of the original, it is not always the best
However, it cannot be said that it is 1, and there is a drawback that it is difficult to select the t%A location with an appropriate concentration.

An object of the present invention is to eliminate the limitations of conventional devices on the measurement locations as described above, and to develop an automatic exposure device that allows the user to freely select nine locations to obtain the appropriate density from within the entire document area. shall be.

The embodiment shown in the drawings will be specifically described.

FIG. 1 is a vertical cross-sectional view of the upper part of the machine box of the copying machine, and FIG. system,
The slit exposure image is formed using a fixing device 1g, a light body cleaning device 1r, and a built-in electrophotographic copying machine, but these process methods are well-known and are omitted from the diagram. Ta.

Of course, this also includes a fixed optical system method for moving manuscripts and a facsimile method.

Reference numeral 6 denotes a document density detector, and a light source lamp 4 illuminates the document Wc inside the box. A lens that can capture the reflected light from the original 5. Direct light blocking plate 7° of the lamp 4 relative to the light receiving element 6° disposed at the image forming point Measurement range 'k ．．
The power cord, the output cord of the light receiving element 6, etc. are 10
It is connected to the adjustment processing circuit in the main body 1 of the copying machine by a cord represented by .

Reference numeral 11 denotes a concentration detector housing chamber provided in a part of the operation panel surface 1a formed on one side of the document table 2 of the copying machine main body 1. When the detector 3 is housed as shown in FIG. A relationship TF is constructed in which the intersection of the optical axes of the lenses 5 coincides with the surface of the original on the operation panel IaO.

FIG. 4 shows a mode in which the detector 6 is taken out from the chamber 11, turned upside down and placed on the surface of a document placed on the document table 2vc, and then measured.

The present invention has the above-mentioned configuration; from b, the copying person directly sets the base portion (the brightest portion) O selected from the entire area of the original 00 on the detector 6 (FIG. 3).

Further, the detector 6t is placed over the selected base portion O of the original (FIG. 4), the original is illuminated with the light source 4, and the reflected light lens 5 images the light receiving element 6KM to read the reflection density t. The output signal of the density (reflectance) of the light receiving element 6 is
Send it to the processing system enclosure as shown in the diagram, and
Adjust the light intensity of the document scanning system O illumination lamp (114 clauses or/and charger, developing bias, lens aperture, sulin) to perform automatic exposure mode.vcl is to obtain the appropriate exposure amount. be.

Figures 6 and 7 show the types of originals to be copied. When there is a slight reflection density, the degree of reflection OIL becomes rich; if it becomes less than a predetermined value on the beam, it depends on the amount of light e potential etc. in the processing system.

The light shielding plate 7 and the aperture plate 8 are useful for improving measurement accuracy.

Conventionally, when the base portion 0 is completely 1, it is common to set the inversion density t to 0, but it is also possible to replace this with t to 1.

The present BA allows automatic exposure light amount adjustment by freely selecting a portion of the entire document where the desired density is desired, and is superior to conventional devices.

[Brief explanation of drawings]

Fig. 1 shows the upper part of an FC copying machine box to which the present invention is applied. 2 is a plan view thereof, FIG. 6 is an enlarged view of the document astringency detector, and FIG. 4 is a closed view of the detector, which is different from FIG. 3. Figures 61 and 7 are illustrative examples of the type of manuscript. 1 is the copy machine box, 2 is the document table glass, 3 is the density detector,
11 is a declaration of containment of intelligence equipment. 5- Figure 5-

Claims (1)

[Claims] (1) A device that can detect the density by freely selecting a 7'hvh location from within the entire area of the document in advance, and by incorporating it into a copying machine and adjusting the exposure amount using its output. Automatic exposure adjustment device.