JPH0443042A - Density-measurement start reference position correcting method in scan system densitometer and its apparatus - Google Patents

Abstract

PURPOSE:To make initial setting operation at a home position easy by a method wherein a distance to a density-measuring start reference position from the home position as a start point is corrected by a drift quantity to obtain a corrected distance, and a position separated by this corrected distance is taken as the density-measuring start reference position, CONSTITUTION:Density of a reference mark 100-1 is fetched to a host computer part 9 accompanying transfer of a density-measuring head. Then, said host computer part obtains a central position of the reference mark 100-1 from the fetched density value by performing specific operation, and a shift quantity LC between a distance LB from a provisional home position 111 to the central position of the reference mark 100-1 and a distance LA from a home position H0 to the central position of the reference LC is substrated from a distance LD from the home position H0 as a start point to the predetermined density measuring start reference position to obtain a correction distance LE. A position separated by this correction distance LE is taken as the density measuring start reference position from the temporary home position H1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for correcting a density measurement start reference position in a scanning densitometer suitable for use in density management of printed matter.

[Conventional technology]

In general, the temperature of printed matter is controlled +lJ1, the color batches printed on the margins of printed matter are measured with a densitometer, and the ink key of the printing frame is measured based on the density value. This is done by controlling the opening degree and the amount of ink flow manually or by the own IJj4.
1. ing.

In recent years, in 4J11, the color par was measured using a scanning densitometer, and compared with the standard density, which had a rough distribution of densitometers.
, automatic density control 4 [4], which controls the ink key opening of the printing press, is provided.

In such an automatic density control tool, the scanning type S-driver is moved from the origin position, and when the dog turns on the rad position detector, the 6th position is set as the base position, and this home position is set. Starting from 1., λ at the predetermined part (i7 "ini ~)", occupy the measurement start reference position r, and start density measurement from the first color batch of the color bar.i) and 1~U 4. [Determine that the invention is f) 21- Problem] However, t(('-) is due to the above-mentioned automatic concentration control system V, ! : By adjusting the dog position of the word, Baum; (6) ',' is used to perform the initial setting of the notion, so there is a problem that the initial setting work is very troublesome. 9 In other words, in the conventional method, the film 100 (see FIG. 4) on which the fiducial mark 1001 and registration mark 100-2 are marked is placed at a predetermined position on the table 200. Alignment with – Z’s upper position 2+,
, set the current home position of the scanning densitometer (not shown) to the opposite home position H1,'; and use this temporary home position H1 as a reference?・Measure the distance LB to the center position of -ri 100-1. This distance if L
, B is measured by measuring the density of the reference mark 100-i while moving the scanning densitometer from the temporary Baume positive, 7th position H1, and the reference mark 100-1 obtained from the completion of the density determination. The number of pulses generated by a rotary encoder (not shown) is obtained up to the center position. Here, since the reference mark 100-1 is set at a certain distance Mc= from the home position 3 HO to be set, the reference mark 100-1 is set from the home position 7 HO.
Distance to the center position of 1, Δ,? 52 The number of pulses generated by the corresponding low clean encoder is uniquely determined.2 From this, the operation is the distance L A f, the corresponding number of pulses and the measured distance L B! Find the difference between the number of pulses and the number of pulses, and calculate the difference between the number of pulses and the resolution of the rotary encoder.
Calculate the deviation amount LC of 12, calculate this 16. Manually adjust the dog position W of the scanning densitometer by the shift position LC obtained by changing the temporary home position H1 to the home position HO.
Initial setting of the Baume position is performed by matching with and -.

In this way, with conventional automatic concentration control devices, the initial setting of the home position is unnecessary! J Annoyance was 7.

[Failure to solve the problem]

The present invention has been devised in order to solve such problems, and a reference mark is defined at a distance position G of -Y with respect to the home position, and a temporary ho, /,
Measure the distance L B from Bonfusion, and this distance L
The difference between B and the distance I, 8 from Baumborgische to the reference ton 1. C is the deviation violet, ' = 1-, and the distance LD from the home position to the predetermined concentration measurement start reference position is corrected to obtain the correction distance LE. The position after the correction distance LP, i is set as the reference position for starting concentration measurement from the temporary home position.

[Effect]

Therefore, according to this invention, the density measurement start reference position starting from the temporary Baume position matches the deepness measurement start reference position starting from the home Baume position without adjusting the temporary Baume position. You will be able to use it.

〔Example〕

Hereinafter, the method and apparatus for correcting the concentration measurement start reference position in the scanning type densitometer according to the present invention will be described in detail.

Fig. 2 is a diagram showing an embodiment of the present invention;
The figure is a schematic diagram of the mechanism of a scanning densitometer.

In the third drawing, when the motor 1 rotates, the pulley 2a
A throat 4 is supported by a guide 5 and moves in the left-right direction in the figure through the wire 3 for concentration measurement. At this time, a pulse signal is generated from the rotary encoder 6 in accordance with the moving distance of the concentration measuring head 4. In addition, 2b is a pulley, 7a
, 7b is a support, and the concentration measuring head 4 has a dog 4-1.
is provided. A head position detector 8 is turned on when the dog 4-1 crosses its optical path as the throat 4 moves toward concentration measurement.

In FIG. 2, reference numeral 9 includes a host computer section, including a keyboard (not shown), a CRT display, a printer,
It is connected to a man-machine interface such as a correction switch. Further, 1o is a measurement timing control section, and 11 is a measurement timing generation section.

Next, based on the flowchart shown in FIG. 1, only the portions related to the present invention will be described with respect to the operation of the apparatus shown in the block diagram of FIG. In this case, the concentration measuring head 4 is moved to the rightmost movement position (origin position) in FIG.
It is assumed that the film 100 shown in FIG. 4 is placed on the table 200 in the same manner as shown in FIG.

In such a situation, when the correction switch is turned on (step 101), driving of the motor 1 is started (
Step 102), the drive of the motor 1 is started when the host computer section 9, which recognizes that the correction switch is turned on, sends a start data block signal S4, and the measurement timing control section 10, which receives this signal S4, starts the drive of the motor 1. This is done by sending a signal SO. As the motor 1 is driven, the density measuring head 4 starts to move, and as the density measuring head 4 moves, the dog 4.1 crosses the optical path of the head position detector 8. As a result, the head position detection signal 312 is given from the head position detector 8 to the measurement timing control section 10, that is, it is confirmed that the head position detector 8 is turned on (step 103), and the measurement timing control section 10 sends the measurement timing signal 312 to the measurement timing control section 10. Timing generation data S2 is provided to the generation unit 11. Upon receiving this timing generation data S2, the measurement timing generation section 11:
Counting of the pulse signal s6 from the low reencoder 6 is started. That is, the time when the dog 4-1 crosses the optical path of the head position detector 8 is defined as the temporary home position H1 of the concentration measuring head 4, and this temporary home position H1
The number of pulses generated by the low-resolution encoder 6 is counted. Then, when the count number of order pulses in the measurement timing generation unit 11 reaches the value specified by the timing order data s2, this time is set as the scan start timing (step 104), and density scanning is started (step 105). . This scanning is
The density signal S9 from the density measuring head 4 is taken in by giving the reading permission signal S8 from the measurement timing generating part II to the host computer part 9. In addition,
The scan start timing in step 104 is determined to always be in front of the reference mark 100-1 marked on the film 100, taking into consideration the maximum deviation amount of the temporary home position H1.

Therefore, when the density scan is started at the scan start timing, as the throat 4 moves to the density measurement,
The density of the reference mark 100-1 can be imported into the host computer section 9 without taking too long. and,
As the timing at which all the densities of the reference marks 100 to 1 can be captured, when the scan end timing is reached, which is determined by taking into account the maximum deviation of the temporary home position and John (
Step 106), the status signal S3 to the measurement timing control unit 1o is set to a stopped state, and the stop signal S3 is sent to the motor 1.
O is applied to return the gutter 4 to the origin position and stop the concentration measurement (step 1o7), and a signal S5 indicating the end of the measurement is applied to the host computer section 9.

Next, the host computer unit 9 calculates the center position of the reference mark 100-1 from the imported density value by performing a predetermined calculation (step 108), and calculates the center position of the reference mark 100-1 from the imported density value (step 108).
Distance LB to the center position of the reference mark 100-1
(calculated value) and reference mark 1 from home position HO
Find the amount of deviation LC from the distance LA (reference value) to the center position of 00-1 (stesoge 109);
When stored in memory, = (step 110),
The concentration measurement start reference position is corrected using this deviation amount LC (
Step i 11). In other words, home posifusilan■
A correction distance LE is obtained by subtracting the deviation 1lLc from the predetermined distance glLD to the concentration measurement start reference position with -10 as the starting point, and a position away from this correction distance LE is temporarily set as Baumebojinoshigon! - (This is the reference position for starting concentration measurement from 1.J+, which makes the temporary home position 9
The concentration measurement start reference position starting from the cell H1 coincides with the concentration measurement start reference position starting from the home positive fusilane HO.

Finally, the corrected distance LE obtained in steps 1 through 1 is stored in the memory (step 112).

After undergoing such processing, the printed material is aligned and placed at a predetermined position on the table 200, and when the measurement switch is turned on in this situation (step l13), the correction distance 13E stored in the memory is is read out (step 114), and then when the motor 1 is driven, the dog 4-1 of the concentration measuring head 4 crosses the optical path, and the head position detector 8 is turned on (step 115).
. As a result, starting from the temporary home position H1 of the concentration measurement radar 4, the number of pulses generated by the low encoder 6 is counted by the measurement timing generator 11, and the count number of the generated pulses is determined by the correction distance. the law of nature.

When the value specified by the timing generation data S2 corrected according to E is reached, this point is determined to be the density measurement start reference position (step 116), and the density measurement from the first color batch of the color bar of the printed matter is performed. Start (step 117).

In this way, according to this embodiment, the current home position (temporary home position I) of the concentration measuring head 4 is determined.
]1) It is now possible to read the density of the color par of a printed matter from the first color batch without missing anything, and there is no need to manually adjust the temporary home position H1 to match the home positive position HO. , the initial setting work can be significantly reduced.

Note that in this embodiment, in step 108,
Although the center position of the reference mark 100-1 is determined, it is also possible to determine the rise or fall of the reference mark 100-1 and determine the distance LB from the temporary home position H1.

〔Effect of the invention〕

As explained above, according to the present invention, a reference mark is set at a fixed distance position with respect to the home position, and the distance L from the temporary home position to this reference mark is
Measure B, and measure this distance I, B and the distance I from the home positive fusilane to the reference mark.

The difference LC between Since the correction distance LE is set as the reference position for starting concentration measurement from the temporary Baum position, the reference position for starting concentration measurement starting from the temporary Baum position is the same as the reference position for starting concentration measurement starting from the home position. This matches the starting reference position, and there is no need to manually adjust the temporary home position to match the home position, thereby significantly reducing the initial setting work.

[Brief explanation of the drawing]

FIG. 1 is a flowchart explaining the operation of the device shown in the block diagram of FIG. 2, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a schematic diagram of the mechanism of a scanning densitometer. FIG. 4 is a diagram showing the film placed on table-L. 1...Motor, 4...Concentration measurement head, 41...
Dog, 6... Rotary encoder, 8... Head position detector, 9... Host combinator section, lO...
Measurement timing control section, 11... Measurement timing generation section, 100-1... Reference mark, HO... Home position, John, Hl... Temporary home position. Patent applicant Komori Printing Machinery Co., Ltd.

Claims (2)

[Claims] (1) Set a reference mark at a certain distance from the home position, measure the distance LB from the temporary home position to this reference mark, and combine this distance LB with the distance LA from the home position to the reference mark. The difference LC is determined as the deviation amount, and the distance LD from the home position to a predetermined concentration measurement start reference position is determined as the deviation amount L.
Concentration measurement in a scanning type densitometer, characterized in that a correction distance LE is obtained by correcting at point C, and a position away from the correction distance LE is set as a reference position for starting concentration measurement from the temporary home position. Start reference position correction method. (2) means for measuring the distance LB from the temporary home position to a reference mark set at a certain distance from the home position; and the difference between the distance LB and the distance LA from the home position to the reference mark. means for determining LC as a deviation amount; and a distance LD from the home position to a predetermined concentration measurement start reference position as the deviation amount L.
A scanning densitometer characterized by comprising: means for correcting at point C to obtain a correction distance LE, and setting a position away from the correction distance LE as a reference position for starting concentration measurement from the temporary home position. Concentration measurement start reference position correction device.