JPH0635168Y2 - Multicolor printing quality evaluation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used for a multi-color printing quality evaluation device, and more particularly, for inspecting the printing state of characters and / or patterns printed in multi-color on paper. Multicolor printing quality evaluation device.

[Conventional technology]

Various methods have been proposed for printing or transferring on copying machines, word processors, electronic typewriters, and the like. For example,
The methods are thermal transfer, dot printing, and laser printer. A print quality device is used to evaluate the quality of these prints themselves and the device used for printing. This device was used to evaluate the printing state of a print and / or a pattern for a single color, that is, a black and white shade (see, for example, Japanese Patent Application No. 63-44459).

In recent years, it has become more and more popular to perform printing or transfer in color, that is, in multiple colors. Evaluating the print quality leads to the recognition of the characteristics, performance, and condition of the apparatus related to multicolor printing and the paper, ink, etc. related to printing. Therefore, it is important to evaluate the print quality printed under a certain evaluation standard. In the case of multicolor printing, a complementary color filter is used for a basic color (usually composed of cyan, magenta, and yellow) (for example, a complementary color yellow ( By using Y) filter, it becomes white, or by using blue (B) filter, it becomes black), and by using a single color, for example, white and black, print quality such as print position deviation, blurring, and gradation An evaluation device is provided. (See, for example, Japanese Patent Application No. 1-178157.) [Problems to be Solved by the Invention] In the above-described multicolor printing quality evaluation device, the light amount is controlled by the voltage of the illumination light source. However, the permeability of the filter varies significantly depending on the filter used. Therefore, the change in the light amount of the light source is very large,
The normal allowable control range may be exceeded. As a result, it has been found that it is difficult to stabilize the amount of light, and the light source body (such as a xenon lamp) that is sometimes used is severely deteriorated.

An object of the present invention is to equip the illumination light source with a diaphragm moving mechanism having a variable transmissivity so that the light amount of the image pickup camera generated when the filter is replaced can be kept within a predetermined allowable range, and accurate multicolor printing quality evaluation can be performed. An object of the present invention is to provide a multi-color print quality evaluation device that can be used.

[Means for solving problems]

According to the present invention, the above object is to provide a paper table on which a paper on which characters and / or patterns are multicolor printed is placed, and a relative movement with respect to the paper table to form an optical path of an imaging optical system, an imaging camera, and an imaging lens. A stage equipped with a holding table equipped with a filter exchange mechanism and an illumination light source device that allow a plurality of optical filters to be exchanged between the image pickup camera and the paper inside, and the focus of the imaging lens along with the filter exchange. A stage having an image forming correction mechanism for correcting the deviation, an electric processing device for electrically processing the relative movement of the stage and the image signal of the imaging camera, and outputting a print quality evaluation result, and displaying the output of the electric processing device. An input / output device for recording and inputting a processing command to this electric processing device, and a multicolor print quality evaluation device, the diaphragm mechanism in the illumination light source device, along with the filter replacement, It is solved by a multi-color print quality evaluation apparatus that maintains the amount of light received in the imaging camera based on the gas treatment apparatus in the allowable range.

[Action]

With the above-described configuration, each time the multicolor filter is replaced, the desired light amount is held by the aid of the diaphragm mechanism based on the electric processing device for the change in the light amount taken in by the imaging camera.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, the multicolor printing quality evaluation apparatus according to the present invention is roughly classified into a mechanical / optical system for moving and imaging a sheet, and an electrical processing apparatus 100 relating to electrical control related to imaging and movement.
And an input / output device 200 for inputting to electrical processing and displaying / recording measurement results.

The mechanical / optical system is the main component of the imaging camera 2
And a stage 1 equipped with the illumination light source device 3, and a sheet fixing base 42 on which a sheet 41 for print quality evaluation is placed. Of these, the mechanical part is composed of a mechanism for moving the stage 1 and the sheet fixing base 42 relative to each other, and the relative movement amount is a detector S _x , S _{y of} a linear length measuring machine in two orthogonal directions, for example, It is detected by a near encoder. This relative movement is determined by electric motors M _x , M _y that relatively move the sheet fixing base 42 in two orthogonal directions based on a predetermined command supplied from the electric processing 100 via the conductive wires 76, 76 ′. .

Further, there is a moving mechanism that moves a plurality of filters 28 used for various colors of the printing ink to set a desired filter 28 on the optical axis of the imaging lens 2 of the imaging camera 2. In this mechanism, there is a filter holding plate 27 that slides in a support table 26 on which the imaging camera L ₀ is placed and carries a filter 28. In the case of this embodiment, this holding plate 27 carries the filters 28 arranged in a straight line, and in order to move the filter 28 with respect to the support base 26, the motor M ₂ installed on the support base 26 and the rotation of this motor are rotated. It is equipped with a filter drive connection 29 which transmits the driving force, which is only implicitly shown, for example consisting of a rack and a pinion.

To adjust the focusing of the imaging lens L ₀ , the stage 1
On the other hand, a mechanism for vertically moving the support base 26 is also incorporated. This mechanism consists of a guide column 22 mounted on a support 26.
And a bearing 11 that slidably holds the column on stage 1.
And it is composed of a vertical movement drive connection 12 and the motor M ₁ for moving the support 22 relative to the stage 1 included with the motor. Although only one column 22 is shown in FIG. 1, it is necessary to equip the support base 26 with at least two columns for stable and smooth horizontal movement.

The optical system includes an imaging lens L ₀ that forms an image on a region of the paper 41 on the imaging detection end 24 of the imaging camera 2, a plurality of filters 28 for multicolors inserted in the optical path, and a diaphragm ST. And paper 41
It is composed of an illuminating device for illuminating the photographing part of. The illuminating device comprises an illuminating light source device 3 for changing the amount of illuminating light and the illuminating light collecting devices L ₁ and L ₂ from the light emitting end portions FC ₁ ′ and FC ₂ ′, for example, via an optical fiber conductor. Light receiving end F
C _1, FC ₂ to feed the paper 41 by the illumination light focusing lens L _1, L ₂
Focus on top. In this case, both illumination condenser lenses L ₁ , L ₂
Are substantially fixed to the support base 26, and are arranged symmetrically in the left and right direction as shown in the drawing in order to uniformly illuminate the paper 41.

Further, FIG. 2 is a side view of the illumination light source device 3. The illumination light source device 3 includes a diaphragm mechanism 31, a light source 32, a condenser lens 33, a light source 32, a motor M _3, and a rack and a pinion connected to the motor M _3. It is composed of fiber conductors FC ₁ ′ and FC ₂ ′. The illumination light source device 3 includes two rails 35 and a concave member of the diaphragm mechanism 31.
39 is fitted, and the diaphragm mechanism is slid up and down by the rack and the pinion 34 connected to the motor M ₃ . In the optical path, the light source 32 passes through the condenser lens 33 and is sent to the optical fiber conductors FC ₁ ′ and FC ₂ ′ via the diaphragm mechanism 31.

Further, in FIG. 3a, each slit 37 of the diaphragm mechanism 31 is
Is made from a very small hole (equivalent to the diameter of a single fiber optic conductor), these slits 37 are all equal in area,
Furthermore, the row intervals of the slits are also equal. The diaphragm mechanism 31 has, for example, the area (L) of the slit 37 per row and the light shielding portion.
If the area ratio is defined as L / D as the area (D) of 38, it is continuously large in the range from the nth column to the mth column.
The diaphragm mechanism 31 is configured so that the L / D value is changed to a smaller L / D value (the number of the slits 37 per one row is proportionally changed).

Similarly, in FIG. 4a, the diaphragm mechanism 43 includes an opening 44 and a shield 45, and the diaphragm mechanism 43 has a width (A) at the α position.
The diaphragm mechanism 43 that moves from the α position to the β position has the opening 44 that forms a triangle and a portion other than the opening as the shielding portion 45 at the middle point (B) at the β position and the β position. The structure is such that the closer it is to the position, the narrower it is proportionally and continuously. In addition, the diaphragm mechanism 43 is shown in FIG.
Since the outer shape is the same as that of the diaphragm mechanism 13 shown in FIG.
In the illustrated illumination light source device 3, instead of the diaphragm mechanism 31, a diaphragm mechanism is provided.
43 can be attached.

Further, FIG. 5 shows another illumination light source device 4, and FIG.
The enlarged view of the diaphragm mechanism 61 is shown. The illumination light source device 4 is
A light source 62 that generates a stable amount of light, a condenser lens 63, a motor M _3, and a diaphragm mechanism 61 fixed to the bearing of this motor 61.
And the light emitting ends FC ₁ ′, FC ₂ ′, for example, optical fiber conductors. The optical path of this device is from the light source 62 to the condenser lens 63.
Through the diaphragm mechanism 61, and the light adjusted by the diaphragm mechanism 61 is sent to the light emitting ends FC ₁ ′ and FC ₂ ′.

Further, in FIG. 6, in the structure of the diaphragm mechanism 61, for example, twelve equal-area elliptical members 66 having the same area are arranged. In the elliptic member 66, a slit portion 64 (diameter of the optical fiber conductor and If the area ratio is defined as L / D, where the area (L) of the slit portion 64 and the area (D) of the shielding portion 65 per area of the ellipse forming body are defined as L / D, an ellipse is formed. The 12 L / Ds of the body 66 are proportionally set so that the L / D values are large to small. The diaphragm mechanism 61
The amount of light can be changed by the elliptical body 66 having such a structure.

The electric processing device 100 includes the motors M ₁ , M ₂ , M _x , M _y M ₃ (mainly stepping motors) for finely moving the mechanical drive unit described above, and the conductors 71, 74, 76, 76 ′, respectively. It has drive circuits 51, 54, 56, 58 which send drive pulses via 78. Further, the electric processing apparatus 100 has two length measuring detectors for detecting the relative position of the paper moving table 42 with respect to the stage 1.
A position amplification circuit 57 that amplifies the position signals of S _x and S _y , and a filter position detector SD, for example, a signal processing circuit 55 of a limit switch (or a photodiode and a phototransistor for photoelectric detection may be used). And a circuit 52 for amplifying and shaping the image signal of the image pickup camera 2.

Further, in the electric processing device 100, a microprocessor electrically connected to each other via a bus line, for example, a RAM or a ROM.
A central operation storage circuit 50 including a storage unit composed of and an input / output I / O is provided. This central processing memory circuit 50
Is supplied with the input signal from the input signal circuits 52, 55, 57 according to the flow of signals shown in the figure, and outputs the output signals 51, 53, 5 with output signals according to the flow of the signals also shown in the figure.
Supply to 4,56,58.

Manual and program control of the electric processing device 100 is performed by a digital or analog input signal from the operation unit 82 formed of, for example, a keyboard, a joystick, a potentiometer, etc. in the input / output device 200. Also, the measurement result of the multicolor print quality evaluation is displayed on the display unit 8 such as a CRT.
1 and a recording unit 83 such as a line printer or a recorder.

Next, a method of using the multicolor printing quality evaluation device according to the present invention will be described. To evaluate multicolor printed characters and / or patterns, a monochrome, black and white imaging camera is used. Therefore, when examining the deviation or bleeding of the printing positions of various colors on a paper that is printed in multiple colors, for example, to check a specific color in the printing ink (for example, to make it yellow), this color Using a filter (blue filter B in this example), which is a complementary color of, the part of this specific color is blackened and imaged. The same yellow filter Y is used to see the yellow portion white (see Japanese Patent Application No. 1-178157). Using this technique, the characters seen through the filter are converted to white or black, and the quality of the multicolored print is evaluated for each color in combination with the above filters. At that time, when the filter is replaced, the captured image is blurred because the light amount of the imaging camera changes and the focus of the optical system shifts. Compensate for this change in light quantity and blurring each time,
It is necessary to analyze the image at the regular focus position. According to the multicolor print quality evaluation apparatus of the present invention, the light quantity and focus are adjusted every time the filter is replaced according to the process shown in FIG.

In the case of the illumination light source device 3 (FIG. 2) (step 90) First, the keyboard 82 is operated to operate the illumination light source drive circuit 53 based on the instruction of the central processing storage unit 50, and the power source of the illumination light source device 3 is turned on. , The paper table 42 is moved relative to the stage 1, and a specific object on the paper in the imaging field of view,
For example, a unique mark for focusing is placed.

(Step 91) Next, when the desired filter 28 is designated with the keyboard 82, the filter movement motor M ₂ confirms that the filter position detector S _D has reached the predetermined filter position based on the command of the central processing storage unit 50. Until the filter holding plate 27 is moved.

(Step 92) When the predetermined filter position is reached, the central processing / storage unit 50 determines whether or not a predetermined amount of light is incident on the imaging camera 2 based on the output of the image signal processing circuit 52. If the amount of light is less than the specified intensity, the central processing / storage unit 50 drives the motor M ₃ via the diaphragm drive circuit 58, and the diaphragm mechanism 31
(FIG. 3a) moves from the n position to the m position, or the diaphragm mechanism 41 (FIG. 4a) moves from the α position to the β position.
The predetermined amount of light is maintained by moving to the position (on the contrary, when the amount of light is equal to or more than the specified amount, the control for maintaining the predetermined amount of light is similarly performed).

(Step 93) In the case of the embodiment, the focusing method for focusing the imaging optical system using the object positioned in the imaging field of view is a binary density curve of the image of the object captured by the imaging camera 2. Is used to determine the edge sharpness (see the related patents filed before this application for the method of measuring the edge sharpness). The support base 26 is moved up and down relative to the stage 1 by a predetermined moving distance by using the motor M ₁ to minimize the image width of the end of the object.

(Step 94) In this state, the light quantity received by the imaging camera 2 is measured again, and if the light quantity is insufficient, the same light quantity adjustment as in Step 92 is performed.

After this operation is completed (step 95), an evaluation analysis of print quality is performed with this replaced filter.

In the case of the illumination light source device 4 (FIG. 5) (step 90) and (step 91) are the same as in the case of the illumination light source device 3.

(Step 92) When the predetermined filter position is reached, the central processing / storage unit 50 determines whether or not a predetermined amount of light is incident on the imaging camera 2 based on the output of the image signal processing circuit 52. If the amount of light is less than or equal to the specified intensity, the central processing / storage unit 50 drives the motor M ₃ via the diaphragm drive circuit 58 and the diaphragm mechanism 61.
The ellipse forming body 66 is rotated, for example, from a large L / D value to a small L / D value to maintain a predetermined light amount.

(Step 93), (Step 94), (Step 95)
This is similar to the case of the illumination light source device 3.

〔The invention's effect〕

In the multicolor print quality evaluation apparatus according to the present invention, by equipping the diaphragm mechanism, it is possible to automatically and stably adjust the change in the light amount of the image pickup camera, which occurs when the filter is replaced, within the allowable control range.

Further, since the light source emits a constant amount of light, deterioration of the light emitting body can be minimized.

Therefore, according to the print quality evaluation program designated by the input / output device, the print quality evaluation of the desired item can be executed completely automatically for all colors or a desired color set.

[Brief description of drawings]

FIG. 1 is a general system diagram of a multicolor printing quality evaluation apparatus according to the present invention. FIG. 2 is an enlarged view of the illumination light source device 3. First
FIG. 3a is a front view of the diaphragm mechanism 31, and FIG. 3b is a sectional view of the diaphragm mechanism 31. FIG. 4a is a front view of the diaphragm mechanism 43, and FIG. 4b is a sectional view of the diaphragm mechanism 43. FIG. 5 is an enlarged view of the illumination light source device 4. Sixth
FIG. 7 is an enlarged view of the diaphragm mechanism 61, and FIG. 7 is a system diagram showing the flow of processing for adjusting the light amount. Reference symbols in the figure: 1 ... Stage, 2 ... Imaging camera, 3, 4 ... Illumination light source device, 28 ... Filter, 41 ... Paper, 42 ... Paper stand, 100 ... Electric processing device, 200 ... … I / O device.

Claims (1)

[Scope of utility model registration request] 1. A paper base on which a paper on which characters and / or patterns are printed in multicolor is placed, and an imaging camera which moves relative to the paper base and is located in the optical path of an imaging optical system, an imaging camera and an imaging lens. A stage having a holding table equipped with a filter exchange mechanism and an illumination light source device capable of exchanging a plurality of optical filters between a sheet and a sheet, and further correcting the defocus of the imaging lens due to the filter exchange. A stage having an imaging correction mechanism, an electric processing device for electrically processing the relative movement of the stage and the image signal of the imaging camera, and outputting a print quality evaluation result, and displaying and recording the output of the electric processing device. An input / output device for inputting a processing command to the electric processing device, and a multicolor printing quality evaluation device, wherein the diaphragm mechanism of the illumination light source device is an electric processing device when the filter is replaced. Based multicolor print quality evaluation apparatus characterized by maintaining the allowable range received light quantities of the imaging camera.