JPH04276480A - Small-sized printing evaluation apparatus - Google Patents

Abstract

PURPOSE:To provide the title apparatus easy to operate, having a simple mechanism and displaying a printing state capable of being measured with good accuracy. CONSTITUTION:A CCD 7, the optical system 6 relatively movable with respect to the CCD 7 and an illumination lamp 5 illuminating the visual field P of paper 1 to be tested are provided to an imaging main body 9 and a transparent cylinder 4 and the support flange 3 connected to said cylinder 4 and placed on the paper 1 are connected to the lower end of the main body 9. Further, a measuring mode can be selected only by the operation key of an operation display unit.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact print evaluation device used to evaluate the transfer characteristics of characters printed on a recording medium using electrostatic printing, laser printers, thermal transfer devices, and the like.

0002

2. Description of the Prior Art Printing devices used for the above-mentioned purposes are already known. For example, Japanese Patent Application No. 1-178158, Japanese Patent Application No. 1-178158,
See -178159. In that case, the print on the recording medium (usually plain paper is used) is optically imaged by an optical system, and the image is transmitted to a photoelectric detector (mainly a CCD imaging detector).
It converts the signal into an electrical signal and evaluates the printing condition electrically. In this apparatus, in order to evaluate the printing condition over a wide range of paper, it is necessary to move the paper relative to the imaging optical system. This moving mechanism also requires a position detection system that detects relative measurement positions with considerable accuracy.

[0003] In recent years, with the development of copying machines, word processors, etc., a large number and variety of printing and recording devices using electrostatic printing, laser printers, and thermal transfer as described above have been used. In the development of these devices, it is necessary to inspect the printing condition of actually printed characters from multiple angles, and highly accurate and multifunctional printing evaluation devices are being produced.

However, in the current situation where this type of printing device is produced in large quantities, general inspection standards are not used for the final inspection of products on the production line or for the maintenance management of printing devices used at the delivery destination. It is becoming increasingly necessary to establish standards and evaluate the condition of equipment according to these standards. These inspection items include, for example, average density within the visual field, line width measurement, line density measurement, MTF (black and white contrast) measurement, line edge roughness measurement, line density slope measurement, toner scattering, and character thickness. Thinness measurement etc. (
These measurement methods are described in Japanese Patent Application No. 1-178158, for example.
(See patent application No. 1-178159). For this kind of general-purpose use, it is rather inconvenient to use a large, expensive, and expensive print evaluation device that has a wide variety of functions, such as the original print evaluation device.

[0005]

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a compact print evaluation device which has limited functions, is easy to operate, and can perform measurements in a short period of time.

[0006]

[Means for Solving the Problems] The above problems are solved by the present invention, which is equipped with an optical system 6 that is movable relative to the CCD unit 7, and an illumination lamp 5 that illuminates the measurement field P of the paper 2 to be tested. This problem is solved by a small print evaluation device in which a transparent cylinder 4 connected to a support flange 3 placed on the sheet 2 is connected to the lower end of the image pickup main body 9.

A further advantageous embodiment is disclosed in claim 2 of the patent claims.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings which exemplarily show one embodiment.

FIG. 1 shows the main imaging part and measurement head of the compact print evaluation apparatus according to the present invention. This measuring head is
It is placed on the paper 1 to be inspected placed on a flat place. The measuring head has a generally cylindrical shape and is provided with a support flange 3 on the lower end of which it can be stably placed. A transparent cylinder 4 is connected to the top of this flange 3. On top of this transparent cylinder 4 is mounted an imaging main body 9 containing the main parts of the imaging system according to the present invention. That is, a focusing lens 6 and the CCD unit 7 for imaging the field of view P of the paper 1 onto an imaging detector, here a CCD unit 7, are arranged in the imaging main body 9. In order to satisfy the above-mentioned optical conditions, the focusing lens 6 is connected to the imaging body 9 through the screw groove 12.
It is fixed inside the lens support cylinder 11 which moves relative to the lens support cylinder 11 . A drive mechanism such as a lever for rotationally driving the lens support cylinder 11 is not shown in FIG. 1 to avoid complexity.

One or more illumination lamps 5 are arranged symmetrically with respect to the axis of the body 9 in order to illuminate the area of the field of view P of the paper 1. The illumination lamp 5 may be a ring-shaped incandescent lamp (halogen lamp) or a plurality of xenon lamps arranged symmetrically with respect to the axis. Of course, in order to increase the illumination efficiency and at the same time reduce the penetration of radiant heat into the interior of the body 9, it is advantageous to respectively arrange one or more corresponding reflectors 13 behind the illumination lamps 5.

Furthermore, in the compact print evaluation device according to the present invention, since the inspection position of the paper 1 can be visually determined, the lower part of the main body 9 is not only formed by the transparent cylinder 4 mentioned above, but also has a flat shape on the flange 3. A flat plate 2 of transparent material is provided which is connected to the . A scale P is attached to the edge of the flat plate 2 on the side of the visual field P so that the position of the visual field P can be determined more accurately. Further, in order to prevent disturbance light from entering during measurement, a light shielding slide cylinder 8 made of an opaque material and movable up and down is provided outside the transparent cylinder 4 and the main body 9 following this cylinder. Although a stopper and the like for regulating the movement position of the cylinder 8 are not shown in FIG. 1, at the time of initial setting, the slide cylinder 8 is raised and the inspection position is determined within the field of view P. Next, the slide cylinder 8 is lowered and measurement is started while preventing light from entering the field of view P from the outside.

The drive power introduced into the CCD unit 7 and the detection signal supplied from the CCD unit 7 are connected to an operation/display unit 20 schematically shown in FIG. 2 via a connector provided on the main body 9 and a cable 10. are doing.

FIG. 2 shows the front panel of the operation/display unit 20 of this print evaluation apparatus. Measuring field of view P to C
It consists of a display section (for example, a CRT or liquid crystal TV display device) that displays the screen imaged by the CD unit 7, a numerical display section 22 that numerically displays measurement results, and operation keys 26. When one of the operation keys 26 is pressed, the following measurement items (1) average density within the field of view (2) line width measurement (3) line density measurement (4) MTF (black and white contrast) measurement (5 ) Line edge roughness measurement (6) Line density slope measurement (7) Toner scattering (8) Character thickness/thinness measurement can be selected. These electrical treatments have already been explained in detail in Japanese Patent Applications Hei 1-178158 and Hei 1-178159.

As already explained with reference to FIG. 1, the small-sized print evaluation device according to the present invention is placed directly on the paper 1 to be inspected, and is not provided with a moving mechanism for moving the imaging body and the paper relative to each other. . Although the moving mechanism itself is complicated and large-sized, and requires the provision of a highly accurate position reading detection section, such a device is omitted in the compact print evaluation device according to the present invention. The measurement is therefore limited to an area defined by the detection surface of the CCD, for example 4x4 mm2, and the magnification of the optical system.

[0015]

Advantages of the compact print evaluation device according to the present invention are that since no moving mechanism is provided between the sample and the imaging body, the device is significantly simplified, easy to operate, reduced costs, and easy to maintain. becomes easier. Moreover, since the scanning area of the CCD has a sufficient area in most cases, highly reliable evaluation results can be obtained. Therefore, it is particularly suitable for manufacturing sites, maintenance services, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing the main parts of an imaging main body in an embodiment of a small print evaluation device according to the present invention.

FIG. 2 is a schematic plan view showing a front panel of a corresponding scanning/display unit.

[Explanation of symbols]

1 Sample 2 Positioning plate 3 Support flange 4 Transparent cylinder 5. Illumination lamp 6 Lens system 7 CCD unit 8 Slide cylinder 9 Imaging body 10 Cable 11 Lens support cylinder 12 Thread groove 13 Reflector S Scale 20 Operation/display unit 22 Numeric display area 24 Image display section 26 Operation keys

Claims (2)

[Claims] Claim 1: At the lower end of the imaging main body 9, which is equipped with an optical system 6 that can be moved relative to the CCD unit 7 and an illumination lamp 5 that illuminates the measurement field of view P of the paper 2 to be tested, a A small print evaluation device characterized in that a transparent cylinder 4 is connected to a supporting flange 3 on which it is placed. 2. A transparent positioning plate 2 with a scale S that allows the position of the field of view P to be read is connected to the support flange 3, and a light-shielding slide that can move up and down is attached to the outer periphery of the transparent cylinder 4. 2. The compact print evaluation device according to claim 1, further comprising a cylinder.