JPH0615969B2 - Printing plate picture area ratio measuring device for offset printing - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern area ratio measuring device for measuring the area ratio of image areas (pattern areas) from a printing plate for an offset printing machine.

By the way, as a method of measuring the pattern area ratio, in addition to the method of measuring the pattern area ratio from a printing plate, there are methods for detecting a proof, a printed matter of this machine, a reflective original, a transparent original, and the like. In addition, there are those that use this measured value to check the density of the printed matter during the operation of the printing machine to perform feedback control, and some that preset the ink supply amount before printing. Thus, in a normal printing plate, the pattern in the printing plate is a pattern in which a plurality of originals are arranged in a predetermined position and printed. Therefore, when a printing plate or something other than this machine printing is used as a measurement target, there is a drawback in that the measurement data must be aggregated after the individual pattern area ratio is measured and the layout on the printing plate is assumed. On the other hand, if you use the printing plate or the printed matter of this machine as the measurement target, you can use the measurement data immediately, but if you obtain the measurement data from the printed matter of this machine, the measurement must be performed after printing is started. Thus, the feedback control system corrects fluctuations due to disturbances during printing. On the other hand, when the measurement data is obtained from the printing plate, the purpose is to preset the opening of the ink adjustment key before starting printing and print a non-defective product from the start of printing.

Here, as an example of an apparatus for measuring a printing plate, a device that winds the printing plate around a cylinder and rotates at high speed to measure an average afterimage of each zone (for example, Japanese Patent Publication No. 47-4220).
No. 5) or an original plate (printing plate) of an offset printing machine to obtain a pulse corresponding to the area ratio of the image area, thereby adjusting the ink supply amount (for example, JP-A-48-53).
No. 804), detects and integrates the image line of the printing plate for each ink adjustment key, and detects the reflected light amount of the non-image line portion using the auxiliary printing plate, and outputs the signal of only the image line portion from the detection signal of the printing plate. A device that calculates and converts the value into a value corresponding to the area ratio of the image line to adjust the ink amount (for example, Japanese Patent Laid-Open No. Sho 49-67714). For controlling the ink supply amount in the ink source roller portion (for example, Japanese Patent Laid-Open No. 51-2505).
No.), a photoelectric detection device is vertically scanned at a predetermined position in the horizontal direction of a printing surface or a plate surface to obtain the total amount of ink and adjust the amount of ink (for example, Japanese Patent Publication No.
47405).

However, none of these devices that detect the printing plate can detect the printing plate with high accuracy, and thus are not practical.

That is, after the printing plate transparent film original is contact-exposed,
Usually, it is processed according to the processing steps of FIG. 1 described below. Here, the phenomenon processing (step 1) of the normally used positive type printing plate is performed in a place exposed to light (non-image area).
This is done to remove the photosensitive layer of and to make it desensitized (to prevent ink from adhering to the surface), but the unnecessary photosensitive layer left in part even after the development process is only in that part. The erasing liquid is applied and dissolved (step S3). Next, after washing with water (step S4), it is dried (step S4).
5) Apply the surface conditioning solution to the entire printing plate (step S6)
Then, buff drying is performed so that the surface conditioning solution does not remain on the printing plate surface, and the printing surface is dried (step 7). These surface conditioning treatment and buff dry are preparatory steps for the burning (high temperature heating) treatment, and the subsequent burning treatment (step S) improves the printing durability of the printing plate by 2 to 3 times. Finally, so-called gumming treatment (step S10) for the purpose of protecting the surface of the non-image area and further enhancing the hydrophilicity.
Then, the printing plate processing step is completed. In such a treatment step, the burning treatment is extremely effective for improving the printing durability of the printing plate, but it is 250 ° C to 300 ° C.
Since the printing plate is heated at a high temperature of ℃, as a result, a normal printing plate based on a hard aluminum plate causes thermal deformation,
Even after cooling, permanent distortion occurs and the flatness of the printing plate deteriorates. Therefore, if the reflected light amount is detected in order to obtain the pattern area ratio from such a printing plate, the reflected light amount changes depending on the pattern area ratio and also changes depending on the degree and deviation of the unevenness of the printing plate. Therefore, it is impossible to accurately set the ink supply amount because a high detection accuracy cannot be obtained.

In addition, where many types of printing machines are unique, it is usual that many types of printing plates are processed in the printing plate printing process. It is preferable to measure the data for ink adjustment of multiple printing machines with one measuring device by using it integrally with the printing plate line at the printing site, rather than using it integrally with the printing machine at the printing site. . Therefore, an object of the present invention is to provide a pattern area ratio measuring device that satisfies such requirements, particularly good operability, it is possible to improve work efficiency and reduce work mistakes, and for installation, or The space required as a work area is also small.

The present invention will be described below.

According to the present invention, as shown in FIG. 2, the printing plate 20 is fixedly mounted below the movable photoelectric detection devices 10 arranged in a line. By moving 10 the detection scanning of the printing plate 20 is performed linearly.

Therefore, the printing plate 20 used here has a calibration mark 23 having a rectangular shape or other shape on the bite butt 22 (bite 21 or a portion that does not adversely affect printing) of the printing plate. , Or a solid part in the image part is set as the mark, and the non-image part (A1 grain part) 2 is set by the calibration mark 23.
4 and the image portion (pattern portion) 25 are discriminated from each other. Further, the photoelectric detection device 10 includes a pair of parallel cylindrical fluorescent lamps 11 and 12 capable of forming a linear irradiation surface, and an intermediate portion of the fluorescent lamps 11 and 12 is shown in FIG. S0, S1, S2, ...
,, Sn photoelectric detectors 13 are provided. Therefore, as shown in FIG. 4, the rotation structure of the photoelectric detectors (S0 to Sn) is such that the font diode PD which receives the reflected light from the printing plate 20 and photoelectrically converts it, and the operation which uses this output as one input Amplifier (the other input is grounded) OP
And a resistor R connected between the input and output of this operational amplifier OP
And a capacitor C. In addition, the photoelectric detector 1
In the structure 3 (S0 to Sn), as shown in FIGS. 5A and 5B, the photodiode PD for photoelectric detection is attached to the upper end of the cylindrical shielding box 14, and the lower end thereof. Is provided with a slit 15 for receiving reflected light. Thus, a light shielding box 17 is provided, which encloses the slit 15 portion of the shielding box 14, shields the fluorescent lamps 11 and 12, and has a slit 16 at the lower part for receiving the reflected light from the printing plate 20. ing. Further, a partition plate 18 for partitioning the optical path is provided between the detection portion of the calibration mark 23 of the shielding box 14 and the portion for detecting the pattern.

Here, the actual configuration of the photoelectric detection device 10 is shown in FIGS. 6 (A), (B), and (C), and the front panel 71 of the measurement device main body 70 has an inclination close to vertical. The front surface of the front panel 71 has a vertical shape and a steep slope. The guide rails 72 and 73 are provided at the upper end and the lower end, respectively, and the center of the front panel 71 is provided. The stage has a convex structure 74 for mounting the printing plate 20. The printing plate 20 is positioned by the pins 75 to 78 and is sucked onto the stage 74 by the suction device 38. The steep inclination of the stage 74 makes it very easy to mount the printing plate 20. This is because the printing plate 20 is normally conveyed in a vertically standing state, rather than in a horizontal state, in order to convey the printing plate 20 in a conveyance space or in a non-deflected state. Since the stage 74 stands by in a state similar to the state of the printing plate 20 at the time of such transportation, the printing plate 20 is transported in a good state, and on the stage 74 without significantly changing its posture. It will be possible to attach it to. The stage 74 is composed of a porous sheet or a plate having a large number of small holes.

Thus, the scanning device 1 having a box-shaped concave structure having the above-described photoelectric detection device 10 built in between the guide rails 72 and 73.
0A is slidably arranged. This scanning device 10A
Has a slope similar to that of the front panel 71, and the intermediate portion, which is a portion between the upper and lower end portions while sandwiching the stage 74 at the upper and lower end portions, is the print 2 on the stage 74.
It is provided so as to face the zero mounting surface at a distance larger than the thickness of the printing plate 20 and to form a concave structure with respect to the convex structure of the stage 74 as a whole. The upper end portion of the scanning device 10A is locked to the guide rail 72 as shown in FIG. 6C, and the upper and lower end portions thereof are slidable on the front panel 71 in the scanning movement direction of the scanning device 10A. It is suspended and supported on the entire surface panel 71 so as to be. The printing plate 20 is inserted and mounted between the scanning device 10A and the stage 74. As shown in FIGS. 6A and 6C, the upper end side of the scanning device 10A is placed on the scanning roll. By driving 31 to move in the M and N directions shown in the figure, the photoelectric detection device 10 arranged below the inside of the device linearly scans the printing plate 20.
Further, an operation input device for designating and inputting the operation of the scanning device 10A, for example, a keyboard 47 in the vicinity of the stage 74 on the front panel 71, and a printer for outputting the result of scanning by the scanning device 10A on printing paper. 48,
A magnetic card output device 100 and a power switch 110 are provided in order to write the result of the scanning by the scanning device 10A to the inserted magnetic card and output the magnetic card for use in the next offsetter printing process. Like this, keyboard 4
By disposing the printer 7, the printer 48, the magnetic card output device 100, the power switch 110, and the like on the front surface of the front panel 71, the operator can search these input / output devices in a front-facing state, Has acquired high operability. The panel arrangement of the magnetic card output device 100 is as shown in FIG. 7, and a card insertion slot 101 for inserting a magnetic card and an insertion for outputting a magnetic card in which predetermined data is written are output. A card outlet 102 provided above the opening 101 and a mode changeover switch 1 for switching the operation mode (check, normal, print)
03 and output mode (magnetic card only, printer only,
An output changeover switch 104 for switching between the magnetic card and the printer) and a lamp 105 for indicating whether the operation is normal or erroneous are provided. Further, the internal structure of the magnetic card output device 100 is as shown in FIG. 8, and the inserted magnetic card 106 is wound around the rubber roller 107 which also serves as a guide via the limit switch SW1 for input detection. Be transported. Then, according to the detection timing of the limit switches SW2 and SW3 arranged at the upper position of the rubber roller 107, the magnetic card 106 is output from the outlet 102 after the predetermined data is written by the magnetic head 108. .

Further, a rotary encoder 36 for detecting the position of the operating device 10A is attached to the rotation shaft of the drive roller 91, and the printing plate 2 attached below the stage 74.
A suction device 38 such as a suction pump for adsorbing 0 is provided.

On the other hand, the arithmetic processing unit 4 for obtaining the pattern area ratio from the detection signal
As shown in FIG. 9, 0 is an amplifier circuit 41 (A0-A0) for amplifying the detection signal from the photoelectric detector 13 for each detection element.
An) and a multiplexer 42 that selectively outputs the signal from the amplifier circuit 41 according to a program for arithmetic processing,
An AD converter 43 for converting the output of the multiplexer 42 into a digital signal, a CPU (microprocessor) 44, a ROM (read only memory) 45 and a RAM (random access memory) as storage devices.
46, a keyboard 47 for inputting data and other required numerical values, a printer 48 for printing out the result of the arithmetic processing, a magnetic card output device 100 for outputting the arithmetic result by a magnetic card, and the AD converter 43. And an input / output control device 49 for controlling input / output with the CPU 44 and the like. The input / output control device 49, CPU 44, ROM 45,
The RAM 46, the keyboard 47, the printer 48, and the magnetic card output device 100 are interconnected by a bus.
The output of the rotary encoder 36 is the reading circuit 50,
The data is input to the CPU 44 via the bus.

In such a configuration, if the photoelectric detector 10, the fluorescent lamps 11 and 12 that detects the amount of reflected light from the printing plate 20, and the printing plate 20 that is the detection target have the following relative positional relationship, a burning process or the like is performed. It is possible to reduce the detection error due to the unevenness of the surface of the printing plate caused by the above.
That is, the above-mentioned "relative positional relationship" means that the fluorescent lamps 11 and 12 are arranged in parallel with the printing plate 20 as shown in FIG. 10, and the printing plate 20 has a distance (2K) between the centers of the fluorescent lamps 11 and 12. 0.35 to 0.70 times, more preferably 0.
Fluorescent lamps 11 and 12 for a distance (X) in the range of 4 to 0.6 times
Set as a reference position apart from the two fluorescent lamps 11,
A measurement in which the periphery P of a position on the plate surface of the printing plate 20 that is equidistant from 12 is set as a detection region, and the photoelectric detector 10 is installed so as to face the printing plate 20 so that only reflected light is received from the detection region P. Refers to the optimum positional relationship. Now, the operation of projecting and receiving light between the photoelectric detection device 10 and the printing plate 20 having such a relative positional relationship will be described. By the way, fluorescent light 1
Since 1 and 12 are linear light sources, their illuminance is inversely proportional to the distance from the light source. In other words, in the case of a point light source, it is inversely proportional to the square of the distance from the light source, so in the case of a point light source, it is considered that the point light sources gathered in a line shape to become a line light source.
When the integral calculation is performed assuming that the illuminance of a surface is the sum of the contributions of all point light sources to the surface, the illuminance is inversely proportional to the distance from the light source. On the other hand, the illuminance of the surface that is not perpendicular to the projected light ray is sin θ times the illuminance of the perpendicular surface, where θ is the angle formed with the perpendicular surface. Therefore, the illuminance I in the detection region P of FIG. 10 is given by I (X) = A · X / (K ² + X ² ) ... (1), where A is a proportional constant. Now, assuming that the printing plate 20 is arranged at a predetermined position X0, the positional deviation due to the unevenness of the surface of the printing plate 20 is ΔX.
If it is 0, there is a difference in illuminance corresponding to the difference between the value when X = X0 and the value when X = X0 + ΔX0 in the above equation (1), and a measurement error is caused accordingly.
By the way, the illuminance I (X) is a function having a maximum value at X = K as shown in FIG. 11, and the change in the illuminance I (X) with respect to the same positional deviation ΔX0 becomes small near the maximum value. Therefore, if the printing plate 20 is installed at a position where X = K and detection is performed by the detector 10 that detects the detection area P, even if the printing plate 20 has irregularities, the measurement can be performed accurately. it can. Also, 0.8K <X <1.2
Even in the range of K, that is, in the range of 0.4 × 2K <X <0.6 × 2K, the characteristic becomes almost linear, and highly accurate measurement is possible.

The operation of such a configuration will be described with reference to the flowchart of FIG.

When the printing plate 20 is installed on the stage 74 via the pins 75 and 76, and the power switch 110 is turned on (step S1), the suction device 38 operates and the printing plate 20 moves to the stage 74.
And the fluorescent lamps 11 and 12 are turned on, and input is performed from the keyboard 47 such as the printing machine number, front printing or back printing in the case of a blanket-to-bracket printing machine (step S2). Further, the mode changeover switch 103 and the output changeover switch 104 are set to desired positions. ROM by these input data
The data set in 45 is set. Such R
As the data of the AM 46 or the ROM 45, the plate size (for example, 1310 mm × 1050 mm, 1160 mm × 94)
0mm) Number of ink adjustment keys (eg 32, 50,
...), key spacing (eg 30 mm, 40 mm, ...), distance between key and plate edge (eg 5 mm, 10 mm,
, Etc.) and the distance between the print effective area and the edge of the plate (for example, top and bottom 22 mm, left and right 20 mm, etc.). As a result, the use range of the photoelectric detector 13 (S1 to Sk in FIG. 3), the interval and the number of ink adjustment keys, and the like are set (step S3), and when the magnetic data is used, the magnetic card 106 is used.
Is inserted into the insertion opening 101 and the measurement start switch is pressed, the motor 93 is driven and the drive roller 9
The scanning device 10A is slidably moved in the M direction or the N direction of FIG. 6 (B) through the scanning device 1 and the scanning rope 31, and the built-in photoelectric detection device 10 including the scanning device 10A moves on the surface of the printing plate 20. It will be detected and scanned. The magnetic card 106 inserted in the insertion slot 101 is taken into the magnetic head 108 via the rubber roller 107. The photoelectric detection device 1
The scanning position of 0 is detected by the rotary encoder 36 and sent to the CPU 44 through the reading circuit 50 and the bus so that the detection position and the timing of the detection scanning movement are matched. Here, the fluorescent lamp 11 of the photoelectric detection device 10
The irradiating lights of 12 and 12 reach the printing plate 20 (or the stage 74) through the slit 16, the reflected light thereof passes through the slit 16 again, and further passes through the slit 15 of the shielding box 14 to reach the photodiode PD, which corresponds to the light amount. It is converted into the amount of electricity. The photoelectric detector S0 in FIG. 3 is a light source light amount (fluorescent lamps 11 and 12) depending on the power supply voltage, the ambient temperature, and the like.
Is detected, and the change is corrected in later data processing. Further, the photoelectric detector SO detects the non-image member 24 and the calibration mark 23 in order to calibrate the upper limit and the lower limit of the reflected light amount, and the photoelectric detector Sk detects the data only by the detector output in the print effective area. Used to take in. It should be noted that the photoelectric detector for performing the calibration is not limited to S0 in FIG. 3, and may be freely selected depending on the calibration position.

Thus, when the position information output from the rotary encoder 36 matches the edge position information of the printing plate set in the program, the reflected light amount of the printing plate 20 is detected by the photodetector 10 (step S4), and the multiplexer 42 is used.
Then, the detected data selected and output according to the program is converted into digital data by the AD converter 43, and then input to the register of the CPU 44 through the input / output control circuit 49 and the bus (step S5). Then, when the data input of the portion corresponding to one ink adjustment key is completed (step S6), the data is transmitted from the register of the CPU 44 to the RAM 46 (step S7). At this time, the detection data of the calibration mark 23 and the light amount of the light source are processed in the same manner. In this way, the output from each photoelectric detector 13 is selectively output by the multiplexer 42, and after AD conversion, it is stored in the address of the RAM 46 corresponding to the detection target (calibration mark, pattern, light source). Is not stored, but is stored by repeating scanning a plurality of times. As a result, the influence of the error due to noise can be reduced. Then, it is determined whether or not all the ink adjustment keys have been fetched (step S8).
Calibration and correction of the light source light amount are performed by the calculation processing of the data of 6, and the total pattern area, the area ratio, and the pattern area ratio for each ink adjustment key are obtained (step S9). In this case, the processing of the detection data corresponding to the ink adjustment key is
ROM45 or RA corresponding to the already set printing machine number
This is performed by selectively using the data such as the ink adjustment key width and the number stored in M46. Thus, the calculated pattern area and area ratio are output from the printer 48 and the magnetic card output device 100 according to the selection mode of the output changeover switch 104 (step S10). Here, an example of the content of the write data of the magnetic card is shown in FIG. 13, and an example of the print is shown in FIG.
The mode switch 103 is in the normal mode at the time of the above measurement, and when the mode is switched to the check mode after the measurement and the output magnetic card is inserted and set in the insertion slot 101, the data of the magnetic card is automatically read. Check if there are any write mistakes. Then,
If there is no mistake, the normal lamp 105 is turned on, and if there is a mistake, the wrong lamp 105 is turned on. In this case, when the magnetic card is set in the insertion slot 101 again, rewriting is automatically performed.

As described above, according to the apparatus of the present embodiment, regardless of the difference in the processing of the printing plate process, the brand of the printing plate, the lot, and the difference in size,
In addition, the pattern area can be accurately measured without being affected by the thermal deformation distortion of the printing plate caused by the burning process and the like, and the measurement corresponding to the ink adjustment key width and the number that are different depending on the type of printing machine used can be performed. . Therefore, a measuring device is not required for each printing machine, only one unit needs to be installed on the printing line, and since it is a measurement from a printing plate, it is different from a measurement from a transparent original (film original), etc. Since the measurement data of the layout is not required and the relative position of the printing plate and the detection device is not easily affected by the mechanical error of the device or the print deformation, the device is simple and low cost, and highly accurate measurement is possible. Is possible. Furthermore, in-line automatic measurement can be performed on the printing plate line, and the work load of measurement is small. Therefore, the measurement data of the pattern area can improve the operating rate of the printing machine by presetting the ink adjustment key in the printing of the printing machine, and it has the effect of reducing the defective printed matter, as well as the preparation for the special color ink. It can be applied to various fields, such as estimating the amount of fuel and reducing fuel consumption by setting the optimum conditions for an off-wheel dryer.

Further, since the data regarding the pattern area can be written in the magnetic card, the work can be automated by sending this magnetic card to the offset printing process of the next process. Further, since the magnetic card is small, it can be easily attached to the printing plate after measurement and is easy to handle, and since the amount of stored information is large, it is convenient for storage for repeated work.

As described above, the present invention is a vertical type in which the stage on which the printing plate is mounted is erected so as to have an inclination close to vertical, and the front surface thereof is a steep slope. Therefore, the mounting work of the printing plate is made very easy. This is because the printing plate is usually conveyed in a state of standing vertically rather than in a state of being laid sideways, in order to convey the printing plate in the conveyance space and in a state where it does not bend. Since the stage will stand by in a state similar to the posture of the printing plate during such conveyance, the printing plate should be conveyed in a good state and mounted on the stage without significantly changing its posture. be able to.

Furthermore, since the stage that is dominant in determining the outer shape of the entire apparatus is a vertical type, the entire apparatus can be a vertical type and the installation space can be kept small.

Furthermore, an input / output device (in the embodiment, a keyboard, a printer, a magnetic card output device, a power switch, etc.) is arranged on the front inclined surface of the front panel, so that the operator can
Since the operation of these input / output devices can be performed with the front facing, the operability is improved.

Further, the scanning device is hung on an inclined stage to determine the vertical position of each of the first and second photoelectric conversion elements forming the photoelectric detector with respect to the stage, and to mount the printing plate on the stage. Since the distance of the photoelectric detector with respect to the surface is determined, if the printing plate is mounted on the stage by the positioning member, the relative distance between the first and second photoelectric conversion elements of the scanning device and the printing area of the printing plate and the calibration mark is determined. The positional relationship is fixed and the calibration is performed accurately.

Further, since the scanning device can be positioned in the vertical direction even if the lower end portion is not particularly positioned as long as only the upper end portion thereof is positioned, the supporting state of the lower end portion of the scanning device does not need to be so tight. Even if only the upper end portion of the scanning device is driven, the lower end portion of the scanning device follows well without being delayed, so that accurate measurement becomes possible. That is, unless the lower end portion of the scanning device properly follows the upper end portion, the lower end portion of the scanning device fluctuates with respect to the printing plate on the stage, and the relative positional relationship with the photoelectric detector cannot be kept good. However, the present invention solves such a problem.

Furthermore, the mechanism of the driving means is simplified by driving only the upper end portion of the scanning device to one side. When the mechanism of the driving means is simplified in this way, the frictional load received from the mechanism is also reduced, and from this point also, the power of the driving means can be reduced.

Further, the gravity component acting from the scanning device to the front panel side is reduced by the inclination of the stage, and the frictional load due to the gravity received by the scanning device is reduced accordingly. Therefore, also from this point, it is possible to contribute to the smooth scanning movement of the scanning device and the reduction in power of the driving means.

[Brief description of drawings]

FIG. 1 is a flow chart showing the processing steps of the printing plate,
FIG. 3 is a diagram showing a positional relationship between a movable photoelectric detection device according to the present invention and a printing plate, FIG. 3 is a diagram showing a state of detection scanning by the photoelectric detection device, and FIG. 4 is a configuration of a detection element in the photoelectric detection device. Circuit diagrams showing examples, FIGS. 5 (A) and 5 (B) are side and front views showing a schematic configuration of a photoelectric detection device, and FIGS. 6 (A), (B) and (C) are measurements according to the present invention. A front view, a plan view, a side view showing an external configuration example of the device, FIG. 7 is a diagram showing an example of a panel arrangement of a magnetic card output device, FIG. 8 is an internal structure diagram thereof, and FIG. 9 is an arithmetic processing according to the present invention. FIG. 10 is a block diagram showing a configuration example of the device, FIG. 10 is a diagram for explaining an optimum relative positional relationship between a printing plate and a fluorescent lamp, and FIG. 11 is a diagram showing a relationship between a distance X and illuminance used for the explanation. , 12th
FIG. 13 is a flow chart showing an operation example of the apparatus according to the present invention, FIG. 13 is a view showing an example of data writing of a magnetic card according to the present invention, and FIG. 14 is a view showing an example of printing by a printer according to the present invention. 10 ... Photoelectric detection device, 11, 12 ... Fluorescent lamp, 13 ...
Photoelectric detector, 14 ... Shield box, 15, 16 ... Slit, 17 ... Shade box, 18 ... Partition plate, 20 ... Printing plate, 21 ... Bite, 22 ... Bite butt, 23 ...... Calibration mark, 24 ...... Non-image area, 25 ...... Image area (print effective area), 36 ...... Rotary encoder, 38
...... Suction device, 40 ・ ・ ・ Processing device, 41 ・ ・ ・ Amplifying circuit, 42 ・ ・ ・ Multiplexer, 43 ・ ・ ・ AD converter, 4
4 ... CPU, 45 ... ROM, 47 ... Keyboard,
48 ... Printer, 49 ... Input / output control device, 50 ...
Reading circuit, 71 ... Front panel, 72, 73 ... Guide rail, 74 ... Stage, 75-78 ... Pin, 10
0 ... Magnetic card output device, 101 ... Card insertion slot,
102 ... Card exit, 103 ... Mode change switch, 104 ... Output change switch, 110 ... Power switch.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryuzo Tamaki 5-2-12 Sagamidai, Sagamihara City, Kanagawa Prefecture (56) Reference JP-A-54-44914 (JP, A) JP-A-53-99271 (JP, A) ) US Patent 3958509 (US, A)

Claims (1)

[Claims] 1. An apparatus for measuring a pattern area ratio from a printing plate for offset printing, in which a calibration mark is attached at a predetermined position outside a print effective area, which is erected so as to have an inclination close to vertical. An apparatus main body having a vertical front panel, a stage formed by a flat plate having a large number of through holes and provided along the front inclined surface on the front panel, and positioning the printing plate on the stage And a positioning member having the same inclination as that of the front panel, and an intermediate portion which is a portion between the upper and lower end portions while sandwiching the stage between the upper and lower end portions has a printing plate mounted on the stage. A light source for irradiating the printing plate placed on the printing plate mounting surface with light, and a light source for irradiating the printing plate mounted on the printing plate mounting surface. Long A first photoelectric conversion element that is arranged in a line in the direction and that detects the amount of reflected light from the calibration mark of the printing plate, and a second photoelectric conversion element that detects the amount of reflected light from the printing effective area of the printing plate. And a scanning device for scanning the printing plate on the stage, and upper and lower end portions of the scanning device are slidable on the front panel in the scanning movement direction of the scanning device. Support means with a guide mechanism for suspending and supporting the scanning device, driving means for causing the scanning device to perform the scanning movement by driving an upper end portion of the scanning device, and inside the device body. A suction device which is provided and sucks and fixes the printing plate through a through hole of the stage, and an input device which is provided on the front inclined surface of the front panel and which inputs an instruction for measuring a pattern area ratio. And, while controlling the suction device and the driving means based on the instruction input by the input device, using the reflected light amount data obtained from the detection signal of the photoelectric detector,
An arithmetic unit having a function of calculating a pattern area ratio of the printing plate by referring to reflected light amount data obtained from a detection signal of the photoelectric detector with respect to the calibration mark, and provided on the front inclined surface of the front panel. An output device for outputting a calculation result of the calculation device, and a printing plate pattern area ratio measuring device for offset printing, comprising: