JPH05188744A - Optical system inspecting method for copying machine - Google Patents

Abstract

PURPOSE:To provide an optical system inspecting method for a copying machine, capable of quantitatively inspecting resolution, magnification, and a deviation in an optical axis, without copying an inspecting chart. CONSTITUTION:An image pickup device 21 for picking up an image on the inspecting chart 32 placed on an original placing glass, is exchanged for a drum inside the copying machine, and installed, many kinds of data of at least, four position detecting marks 31 and a resolution inspecting mark 30 on the inspecting chart 32, are stored in a data memory 22, in advance, to compare with image information from the image pickup device 21, and many kinds of data detected from the image outputted by the image pickup device 21, are compared with many kinds of data stored in the data memory 22, to inspect the deviations in focus, the magnification, and the optical axis, generated on the optical system of the copying machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting an optical system of a copying machine, which measures and inspects a focus deviation, a magnification deviation, and an optical axis deviation which occur in an optical system of the copying machine.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram of a conventional copying machine optical system. To inspect the copying condition of the copier, the copier optical system 1
An inspection chart 20 having marks for inspecting the resolution, magnification, and optical axis is placed on the upper surface 2 of the, and toner is actually supplied to the copying machine to make a copy on a paper or the like, and the copy state is visually observed. I was inspecting. The copier was adjusted by controlling and moving the optical system from this copying state to readjust the focus shift, magnification shift, and optical axis shift.

[0003]

In the conventional optical system inspecting method for a copying machine, since the actual copying must be performed as described above, the toner must be supplied to the copying machine. Therefore, after the inspection is completed, it is necessary to remove the toner from the copying machine, which requires a great deal of labor for the removal and cleaning work. Further, since the copied inspection chart is visually inspected, the degree of fatigue of the operator is high and the inspection result may vary.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical system inspection method for a copying machine, which can quantitatively inspect the resolution, magnification, and deviation of the optical axis without copying the inspection chart.

[0005]

In order to achieve the above object, in the optical system inspection method for a copying machine according to the present invention, at least four position detection marks mounted on the four corners of the original mounting glass surface are provided. In the optical system inspection method of a copying machine, which uses a resolution inspection mark having gradation, an image of each of the above marks is inspected for a focus shift, an optical axis shift, or a magnification shift for copying that occurs in the optical system. An image pickup device for this purpose is installed by replacing the drum in the copying machine, and the position information of the position detection mark and the density information of the image of the resolution inspection mark are previously stored in the data memory for comparison with the image information from the image pickup device. The position information of the position detection mark and the density information of the image of the resolution inspection mark are detected from the output image of the imaging device, and the detected data and the data memory are recorded. It is characterized in that as has been inspected as compared to the optical system of each data.

[0006]

With the image pickup device in the copying machine, at least four position detection marks and resolution inspection marks having gradations placed on the four corners of the original placing glass surface are irradiated with light from the light source, and an optical system is provided. And the image is picked up at the focal position of the optical system. Further, in the data memory, the position information of the position detection mark and the density information of the image of the resolution inspection mark are stored in advance for comparison with the image information from the image pickup device.

Then, after detecting the position information of the position detection mark and the density information of the image of the resolution inspection mark from the output image of the image pickup device, the detected data and the data stored in the data memory are detected. Are compared, and the inspection of the density level of the resolution inspection mark, the inspection of the optical axis shift between the position detection marks, and the inspection of the magnification of copying are performed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a copying machine according to the optical system inspection method for a copying machine of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a copying machine according to the optical system inspection method for a copying machine of the present invention. A mounting glass 2 on which an inspection chart 32 (FIG. 2) on which at least four position detection marks 31 and resolution inspection marks 30 are drawn is placed is provided on the upper surface of the copying machine optical system 1. .. The optical system 1 emits light from the light source 4 of the first carriage 3 and illuminates the inspection chart 32. The light emitted from the inspection chart 32 is reflected by the first reflecting mirror 5 of the first carriage 3, is reflected by the second reflecting mirror 7 and the third reflecting mirror 8 of the second carriage, and is formed by the imaging lens 9 Incident on. The first carriage 3 is adapted to reciprocate along the document mounting glass.

The second carriage 6 reciprocates along the mounting glass at a 1/2 pitch when the first carriage 3 moves. The mark 30 is
The black portions 30a and the white portions 30b are alternately arranged in a line. The mark 31 is a cross line, and its position is
As shown in the figure, there are two patterns 31a and 31b at the tip,
Two patterns 31c and 31d are arranged at the rear end (FIG. 2). The light that has passed through the imaging lens 9 is reflected by the fourth reflecting mirror 11 and the fifth reflecting mirror 12 of the third carriage 10 and enters the reflecting mirror 13. The light reflected by the reflecting mirror 13 is captured by an image pickup device 21 such as a CCD camera.
The third carriage 10 is configured to be movable and rotatable in a direction parallel to the mounting glass 2 (FIG. 3).

Next, the inspection method using the inspection chart 32 will be described in detail. In this apparatus, first, 1) the maximum density BL of the resolution inspection mark 30 of the reference inspection chart 32 is stored in the data memory 22. 2) The center 31a, the center 31b, the center 31c, and the center 31d of the position detection mark 31 of the inspection chart 32 at the time of imaging as a reference are stored. 3) Then, the distance Lr between the centers is stored.

(1) A method for inspecting a focus (shading level) deviation of the copying machine of the present invention and an adjusting means therefor will be described with reference to the resolution inspection mark 30 shown in FIG. With this device, the resolution inspection mark 30 of the inspection chart 32 (FIG. 4A)
When the white portion 30a and the black portion 30b of the above are subjected to shading processing and measured, a shading graph as shown in FIG. 4B is obtained. The optical system inspection unit 23 inspects the density of the white portion 30a, Imax, the density Imin of the black portion 30b, and the maximum density BL stored in advance in the data memory 22, according to the following equation 1. f = (Imax−Imin) / (2 × BL− (Imax + Imin)) (Equation 1) The value of this evaluation value f is used as the focus inspection result. The focus adjusting means moves the third carriage 10 in a direction parallel to the mounting glass 2, finds a position where the value of f at that time is maximum, and fixes the third carriage 10.

(2) Next, a method for inspecting a deviation in magnification and its adjusting means will be described with reference to the position detecting mark 31 shown in FIG. The distance Lr (FIG. 5A) between the center 31a and the center 31b of the actual position detection mark 31 stored in the data memory 22 and the distance between the center 31c and the center 31d of the position detection mark 31 measured by this device. L
m (FIG. 5B) B = Lm / Lr × 100 (%) (Equation 2) The optical system inspection unit 23 inspects whether or not they match (n≈B) according to Equation 2. The magnification adjusting means moves the imaging lens 9 in a direction parallel to the mounting glass 2, and the value of B at that time is (n
This is done by finding the position where the value of ≈B).

(3) Next, a method for inspecting the deviation of the optical axis and an adjusting means will be described with reference to the position detecting mark 31 shown in FIG. The positions of the center 31a and the center 31b of the cross line of the position detection mark 31 in the image pickup device 21 when the first carriage 3 of the present device is at the tip of the mounting glass 2 are measured. Next, the position data measured by measuring the positions of the center 31c and the center 31d of the cross line of the position detection mark 31 in the image pickup device 21 when the first carriage 3 is at the rear end of the mounting glass 2 are obtained. Be done.

The measured position data and data memory 2
The optical system inspection unit 23 measures and inspects the deviation amount of the optical axis from the positional relationship of the position data of the position detection mark 31 stored in 2. The optical axis adjusting means is the third carriage 10 described above.
Is adjusted by controlling the rotation of the.

Although three types of inspection and adjustment methods have been described above, in the present inspection chart 32, since the position detection mark 31 and the resolution inspection mark 30 are close to each other, both of them are included in one visual field of the image pickup device 21. Because you can put a mark,
It also has the feature that all inspections can be performed at once. Although the cross line is used in the magnification of the inspection chart 32 and the optical axis inspection chart 31, this is used for clarifying the position, and points may be used instead of the cross line. The maximum density BL of the resolution inspection mark 30 and the distance Lr of the position detection mark 31 in the data memory 22 can be stored again according to the light amount of the light source.

[0016]

As described above, according to the optical system inspection method for a copying machine of the present invention, the inspection chart is imaged by the image pickup device in the copying machine, and the resolution, magnification and optical axis are inspected and adjusted. There is no need to duplicate the inspection chart, and the labor of removing and cleaning the toner by copying can be saved.
Furthermore, visual work saves time and effort.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a copying machine using an optical system inspection method for a copying machine according to the present invention.

FIG. 2 is an inspection chart used in the copying machine of FIG.

FIG. 3 is a movable direction diagram of a third carriage 10 of FIG.

FIG. 4 is an explanatory diagram of a method of inspecting a focus shift of the copying machine of FIG.

5 is an explanatory diagram of a method for inspecting a magnification deviation of the copying machine of FIG.

6 is an explanatory diagram of a method of inspecting a deviation of an optical axis of the copying machine of FIG.

FIG. 7 is a block diagram of a conventional copying machine.

[Explanation of symbols]

 21 CCD camera (imaging device) 22 data memory 23 optical system inspection section 32 inspection chart

Claims (1)

[Claims] 1. A focus shift or light generated in an optical system using at least four position detecting marks and resolution checking marks having gradations which are placed on the four corners of the original placing glass surface. In an optical system inspection method for a copying machine for inspecting an axis deviation or a magnification deviation for copying, an image pickup device for picking up each of the above marks is installed in place of a drum in the copy machine, and image information from the image pickup device is exchanged. For comparison, the position information of the position detection mark and the density information of the image of the resolution inspection mark are stored in advance in a data memory, and the position information of the position detection mark and the resolution inspection image are output from the output image of the imaging device. Copying characterized by detecting density information of the image of the mark and comparing the detected data with the data stored in the data memory to inspect the optical system. Optical system inspection method.