JP2000241247A - Colorimetric instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the colorimetric instrument which is actualized at low cost, has a mechanism automatically holding constant the distance between a measurement surface for measuring a color or density and an object to be measured, and is able to precisely measure the color or density. SOLUTION: One bearing 150 each is fitted to both the end parts of one flank parallel to the width direction of a colorimeter 34 of a casing 140 mounted with the colorimeter. One bearing 150 is fitted to the center part of the opposite flank. As a timing belt 132 which is driven by a motor moves, the casing 140 moves rotating the bearings 150 on image receiving paper 40. Consequently, the casing 140 is supported at three points by the bearings 150 with the highest stability and moves while holding the measurement surface (reverse surface of measurement part 144A) of the colorimeter 144 and the image receiving paper 40 at a specific interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a colorimetric device,
In particular, the present invention relates to a colorimetric device that measures density or color while scanning a surface to be measured of a measurement object.

[0002]

2. Description of the Related Art Image forming apparatuses are required to reproduce density and stability, that is, to always form data of the same density at the same density. For this reason, calibration of the image forming apparatus is important.

In order to perform calibration, it is necessary to print a test image stored in advance on an image receiving paper and measure the finished density or color with a high-precision colorimeter or density measuring device. FIG. 15 shows a schematic configuration of a conventional colorimeter.

As shown in FIG. 15, a color measuring device 200 is provided with a measuring device 202 for measuring a color, with a measuring surface facing downward. The measuring device 202 is supported at both ends by a pair of cylindrical support members 204, and can move in the axial direction of the support member 204 indicated by an arrow E. Below the measuring device 202, the measuring device 20
The base plate 206 is arranged at a predetermined interval from the second measurement surface. At both ends of the base plate 206 in the direction orthogonal to the moving direction of the measuring device 202 (arrow E), a pair of transport rollers 20 is provided.
8, 210 are provided. The image receiving paper 212 is guided onto the base plate 206 by the pair of conveying rollers 208, and is conveyed in the direction of the conveying rollers 210 (the direction indicated by arrow F). Therefore, in the conventional colorimeter 200, the measuring device 202 is moved (main scanning) while being supported by the support member 204 while the image receiving paper 212 is being conveyed (sub-scanning), and the image receiving paper 2
The color of the test image formed in No. 12 was measured.

By the way, the measured value of the colorimeter or the density measuring device is determined by the distance between the measuring surface and the image receiving material (hereinafter referred to as "measurement distance").
Depends). Therefore, it is required that the distance between the measurement surface and the image receiving material be kept constant during scanning by the colorimeter or the density measuring device.

[0006]

However, conventional colorimetric devices and density measuring devices have not been provided with any means for keeping the measurement distance constant. For example, when the base plate is bent, the measurement distance changes because the image receiving material also follows the bend of the base plate, and accurate color or density measurement cannot be performed. For this reason, the image forming apparatus cannot execute highly accurate calibration. In addition, even when the image receiving material floats on the base plate due to the curl of the image receiving material or the like, highly accurate calibration cannot be performed.

In view of the above facts, the present invention has a mechanism which can be realized at low cost and has a mechanism for automatically keeping the distance between the measurement surface for measuring color or density and the object to be measured, so that the color or color with high accuracy can be obtained. An object of the present invention is to provide a colorimeter capable of measuring density.

[0008]

According to one aspect of the present invention, there is provided a colorimeter for measuring a density or a color while scanning a surface to be measured of an object to be measured. A measuring device provided on the vehicle body with a measurement surface for measuring density or color facing the object to be measured, so that a distance between the measurement surface and the surface to be measured is kept constant, A support unit that is provided so as to protrude toward the surface to be measured, and supports the vehicle body on the object to be measured, and holds the vehicle body on the object to be measured while maintaining the spacing dimension constant by the support unit. And conveying means for conveying.

According to the first aspect of the present invention, a colorimetric device includes a measuring device, a support means, and a transport means. The measuring device is provided on the vehicle body with the measuring surface facing downward, and the measuring device measures the density or color of the surface to be measured of the object to be measured. The support means is also provided on the vehicle body toward the surface to be measured of the object to be measured. By this support means, the vehicle body is supported on the object to be measured so as to maintain a constant distance (measurement distance) between the measurement surface of the measuring instrument and the surface to be measured of the object. The transport means transports the vehicle body over the measurement object while maintaining a constant measurement distance. Thus, the measuring device can perform density measurement or color measurement by scanning the surface to be measured while keeping the measurement distance constant.

According to a second aspect of the present invention, in the first aspect of the present invention, the support means is a roller, and is rotated by the transport of the transport means to transport the vehicle body. .

According to the second aspect of the present invention, the vehicle body
The rollers are supported by rollers, and are conveyed by the rotation of the rollers that have received a driving force by the conveying unit. The roller has a small contact area with the surface to be measured, and the force required to convey the vehicle body to the conveying means is small. Therefore, the measuring device can scan the surface to be measured with a small driving force.

According to a third aspect of the present invention, in the second aspect, the vehicle body is provided with three rollers and supported at three points.

According to the third aspect of the present invention, the vehicle body is
Supported by two rollers. That is, since the vehicle body is supported by the most stable three-point support, the vehicle body does not shake due to unevenness of the surface to be measured. Further, even when the surface to be measured is curved, the vehicle body can be transported following the curve, and the change in the measurement distance can be reduced.

[0014] Also, in the measurement of a curling object such as paper, which is pressed down at three points, it is possible to extend the curl and measure the color or density.

As described above, the present invention has a mechanism which can be realized at a low cost and has a mechanism for automatically keeping the distance between the measurement surface for measuring color or density and the object to be measured, thereby providing a highly accurate color or density. A colorimetric device capable of measurement can be provided.

[0016]

Next, an example of an embodiment according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows an image forming apparatus 14 including a colorimetric apparatus according to the present invention.

FIG. 1 shows an image forming apparatus 14 according to the present embodiment.

The image forming apparatus 14 includes the image exposing device 10 and the heat developing device 12.

The image exposure apparatus 10 includes a photosensitive material loading section 18.
, A correction circuit 20, a correction data creation unit 22, and an exposure unit 24. The thermal developing device 12 includes a face 26, a thermal developing unit 28,
The apparatus includes a photosensitive material take-up unit 30, an image receiving / feeding unit 32, a colorimetric device 34, and a temperature / humidity sensor 36.

The photosensitive material loading section 18 of the image exposure apparatus 10 is loaded with the photosensitive material 16 wound around a winding shaft 38. The photosensitive material 16 loaded in the photosensitive material loading section 18 is transported in a predetermined direction by driving a transport roller (not shown). An exposure unit 24 is provided downstream of the photosensitive material 16 in the transport direction. The exposure unit 24 is provided with a laser 46, and emits a light beam from a laser head (not shown). The output end of the correction circuit 20 for correcting image data is connected to the laser 46, and the corrected image data generated by the correction circuit 20 is input. That is, the exposure unit 24 uses the laser 4 based on the corrected image data.
6 is instructed, and the photosensitive material 16 is exposed by scanning with a light beam. Thereby, the photosensitive material 16
The image is written to

The exposure unit 24 has a central angle of about 1
An 80 ° arc-shaped drum 78 is provided, and the photosensitive material 16 is wound and conveyed along the inner peripheral surface of the drum 78, and a light beam is applied to the photosensitive material 16 from the inner peripheral direction of the drum 78. (So-called inner spinner type).

The output terminal of the correction data generator 22 is connected to the correction circuit 20 described above. The correction data creating unit 22 includes a temperature and humidity sensor 3 provided in the heat developing device 12.
6 and the output end of the colorimetric device 34 are connected. The temperature / humidity sensor 36 is a sensor that detects the temperature and humidity in the heat developing device 12, and the colorimetric device 34 measures the color of the image recorded on the image receiving paper 40 that has been heat-developed by the heat developing unit 28. It is a sensor.

The correction data creating section 22 stores test image data for calibration.
Therefore, the correction data creation unit 22 compares the stored test image data with the temperature and humidity sensor 36 and the colorimetric device 34.
The correction data used when correcting the image data in the correction circuit 20 is created from the detection (measurement) data obtained by the above.

An operation panel (not shown) is mounted on the upper surface of the image exposure apparatus 10. On this operation panel, one of an image forming processing mode for performing normal image forming processing and a color measuring mode for performing calibration can be selected.

Next, details of the internal structure of the heat developing device 12 provided adjacent to the image exposure device 10 will be described with reference to FIG.

As shown in FIG. 2, a face portion 26 is provided in the vicinity of a connection portion of the thermal developing device 12 with the image exposure device 10. A branch guide (not shown) operated by a solenoid is disposed on the face portion 26. The branch guide is switched between a horizontal state and a vertical state. When the branch guide is switched to the vertical state, as shown by the imaginary line in FIG.
During this time, the photosensitive material 16 can be loosened. Thereby, a speed difference between the processing speed of the heat developing device 12 and the processing speed of the image exposure device 10 can be absorbed. The driving of the transport roller 42 is controlled by a control unit 94 provided below the thermal developing device 12.

Below the face section 26, an image receiving / feeding section 32 is provided. Image receiving paper 40 wound around a take-up shaft 44 is loaded in the image receiving and feeding unit 32, and is transported by a transport roller 42 in a predetermined direction.

A heat developing unit 28 is provided downstream of the photosensitive material 16 in the transport direction. Thermal development unit 28
Is provided with a water application section 80 in which the photosensitive material 16 is filled with water as a solvent for image formation.

The water application section 80 is supplied with water by a pump 81 from a water tank 82 provided below the thermal developing device 12. By coating the photosensitive material 16 with water, the adhesion when the image receiving paper 40 and the photosensitive material 16 are bonded to each other can be improved.

The heat developing unit 28 is provided with a heat developing drum 84 which rotates in the direction of arrow A shown in FIG. A heater 100 is housed in the center of the thermal developing drum 84. That is, heater 1
As a result, the heat developing drum 84 is heated.

As a result, the photosensitive material 16 and the image receiving paper 40 conveyed along the outer peripheral surface of the heat developing drum 84 are heated for a predetermined time (that is, subjected to thermal development processing), and an image is formed on the image receiving paper 40. A belt 86 for preventing slippage is provided near the outer periphery of the heat developing drum 84.
Photosensitive material 16 and image receiving paper 40 conveyed along the outer peripheral surface of
The deviation is prevented so that an image is accurately formed on the image receiving paper 40.

On the downstream side of the thermal developing drum 84 in the transport direction of the photosensitive material 16 and the image receiving paper 40, a photosensitive material peeling member 88 for peeling off the photosensitive material 16 bonded to the image receiving paper 40, and the image receiving paper 40. Is provided with a separating member 90 for an image receiving paper for separating the sheet from the heat developing drum 84.

The image receiving paper 4 is separated by the photosensitive material separating member 88.
The photosensitive material 16 that has been peeled off is wound around a winding shaft 92 provided in the photosensitive material winding section 30, and is disposed as waste material. Further, the colorimetric device 34 is disposed on the downstream side in the transport direction of the image receiving paper 40 on which an image has been formed after being peeled off from the thermal developing drum 84 by the image receiving paper separating member 90. The details of the colorimetric device 34 will be described later.

When the image forming process mode is selected on the operation panel, the image receiving paper 40 passes through the colorimetric device 34 as it is and is discharged to the outside of the heat developing device 12.

When the colorimetric mode is selected on the operation panel, a test image is formed on the image receiving paper 40 based on the test image data for calibration. The colorimeter 34 measures the color of the test image formed on the image receiving paper 40. At this time, since the colorimetric device 34 is built in the device, color measurement can be performed without being affected by external light. The obtained measurement data is transmitted to the correction data creation unit 22. The image receiving paper 40 whose color has been measured by the colorimetric device 34 is
Is discharged to the outside.

FIG. 3 shows the image receiving paper 40 on which the test image is formed. The arrow B shown in FIG.
Indicates the transport direction of the image receiving paper 40 in the colorimetric device 34, that is, the upward direction of the image receiving paper 40.

At the center of the image receiving paper 40, a test image 10
2 is printed. The test image 102 corresponds to the test image data for calibration stored in the correction data creation unit 22 described above.

The upper end of the test image 102 is the laser 4
6 corresponds to the image writing start position. Also,
The left-right direction of the image receiving paper 40 (hereinafter, the “width direction of the image receiving paper 40”)
) Corresponds to the axial direction of the heat developing drum 84 described above. The data stored at the start address of the calibration test image data storage area of the correction data creation unit 22 corresponds to the upper right part of the test image 102.

In the test image 102, a plurality of density areas (hereinafter, referred to as "patches") 103 are formed.
The patches 103 are arranged so as to have different colors (so-called color patches). Note that the patch formed on the test image 102 may be a so-called gray patch in which the color of each patch 103 is determined to be a shade of gray and arranged so as to be a gradation.

Above the print position of the test image 102, the first reference line 104 is printed in black over the width direction of the image receiving paper 40. An interval of a predetermined length T1 is provided between the first reference line 104 and the test image 102. From the first reference line 104, the print position of the test image 102 in the vertical direction of the image receiving paper 40, that is, the write start position (laser irradiation start position) by the laser 46 can be recognized.

A second reference line 106 is printed in black in one of the left and right directions from the print position of the test image 102 in the axial direction of the image receiving paper 40. In the present embodiment, the second reference line 106 is printed on the right side of the test image 102. An interval of a predetermined length T2 is provided between the second reference line 106 and the test image 102. From the second reference line 106, the test image 1 in the width direction of the image receiving paper 40
02 can be recognized. This makes it possible to correspond to the position of the heat developing drum 84 in the axial direction.

The first reference line 104 and the second reference line 106 are written on the photosensitive material 16 in the exposure unit 24 together with the test image data. Therefore, the relative positional relationship between the test image 102, the first reference line 104, and the second reference line 106 on the image receiving paper 40 is always the same (every time).

Next, the configuration of the colorimetric device 34 will be described. FIG. 4 is a schematic sectional view of the colorimeter 34, FIG. 5 is a schematic side view of the colorimeter 34, and FIG. 6 is a schematic bottom view of the colorimeter 34.

As shown in FIGS. 4 and 5, the colorimeter 3
4 is provided with a box-shaped casing 140 having an upper surface opening. Facing the bottom surface of the casing 140, the base plate 1
52 are provided. The above-mentioned image receiving paper 40 is
2 and the casing 140, and is conveyed from above the image receiving paper 40 in the direction of arrow B shown in FIG.

On the bottom surface of the casing 140, the width direction of the colorimetric device 34 (the direction indicated by the arrow C in FIGS. 5 and 6).
One end (the left end in FIG. 5) and the center in the axial direction are cut out in a rectangular shape to form a through hole 140A. The tapered bottom center of the colorimeter 144 (hereinafter, referred to as “measurement unit 144A”) is fitted into the through hole 140A, and the colorimeter 144 projects the measurement unit 144A from the lower surface of the casing 140. It is placed on the casing 140.

The colorimeter 144 measures the color of the image formed on the image receiving paper 40 guided below the colorimeter 144, with the lower surface of the measuring section 144A serving as the measurement surface 146. The colorimeter 144 irradiates the light to the image receiving paper 40 and detects the reflected light (detects a so-called spectral tristimulus value). From this detection result, the lightness index L in the Lab color system, the perceived chromaticity The chromaticity is measured by obtaining a and b.

A reflection type photo sensor 148 is attached to the bottom surface of the casing 140 and at the end in the width direction. The reflection type photo sensor 148 receives the reflected light (from the image receiving paper 40) of the light emitted by itself, and flows a current corresponding to the received reflected light amount. By measuring this current value, the density of the image receiving paper 40 can be measured. In the embodiment of the present invention, the first reference line 104 and the second reference line 106 are determined based on the presence or absence of reflected light detected by the reflective photosensor 148 by utilizing the characteristic that black does not reflect light. It is designed to detect.

Also, metal bearings 150 are provided at both ends of one side surface (the right side surface in FIG. 4 and the front side surface in FIG. 5) of the casing 140 parallel to the width direction of the colorimetric device 34. They are attached one by one. Also, the facing side surface (the left side surface in FIG. 4 and the back side surface in FIG. 5)
One bearing 150 is also attached to the center of the.

These bearings 150 are used for the colorimeter 14
The distance H between the measurement surface 146 and the image receiving paper 40 (hereinafter referred to as “measurement distance”) is set to a predetermined value (5 mm in this embodiment).
The casing 140 is supported so as to be maintained at ± 25 μm). Also, the casing 140 has three bearings 1
By 50, the color is supported by the most stable three-point support and is moved by the rotation of the bearing 150, and the color of the image receiving paper 40 is measured. At this time, even if the base plate 152 has a curve, the casing 140 moves following the curve, so that the measured distance H hardly changes.

Further, since the bearing paper 150 presses the image receiving paper 40 against the base plate 152 at three points, even if the image receiving paper 40 is curled, the curl can be extended and brought into close contact with the base plate 152.

A bolt 142 is attached to the upper portion of the casing 140 at the center on both sides parallel to the width direction of the colorimetric device 34.

A lid 136 having a substantially U-shape with its opening facing downward is provided on the upper portion of the casing 140. The central portion of both sides of the lid 136 is cut downward at a constant width except for an upper quarter (hereinafter, referred to as a “cut portion 136A”).
The cover 136 is secured to the bolt 1 by the cutout 136A.
It is engaged with the casing 140 with 42 interposed therebetween.

Thus, the casing 140 is fixed to the lid 136 in the width direction of the colorimetric device 34. Further, it can freely move in the vertical direction by the height of the cutout portion 136A. That is, the cut-out portion 13
6A makes it possible to absorb unevenness in the vertical direction of the base plate 152 and the image receiving paper 40 and changes in the thickness of the image receiving paper 40.

At the upper center of the lid 136, a shaft 120 longer than the width of the image receiving paper 40 is provided in parallel with the width direction of the colorimetric device 34. The shaft 120 is loosely fitted to a pair of bushes 138 formed in a cylindrical shape. The bush 138 and the lid 136 are connected to the connecting member 13.
4. Thereby, the casing 14
The movement direction of 0 is maintained in the width direction of the colorimetric device 34 by the shaft 120. That is, the colorimeter 144 can be moved only in the width direction of the image receiving paper 40.

The colorimeter 3 is located above the lid 136.
4 and at intervals longer than the width of the image receiving paper 40, belt rollers 122 (left side in FIG. 5), 12
8 (right side in FIG. 5). Belt roller 12
2, a motor 124 is connected to the belt roller 1
Reference numeral 22 is rotated by driving of a motor 124.

Further, a loop-shaped timing belt 132 is hung around the belt rollers 122 and 128. A part of this timing belt 132 is
6 is attached to one end (the left end in FIG. 4) in the direction orthogonal to the width direction of the colorimetric device 34.

The casing 140 receives the rotation of the belt roller 122 driven by the motor 124 and moves in the width direction of the colorimetric device 34 together with the timing belt. That is, the colorimeter 144 can be moved in the width direction of the image receiving paper 40 by driving the motor 124.

The driving of the motor 124 is controlled by the control unit 94. The control unit 94 will be described with reference to FIG.

The control unit 94 has a built-in microcomputer, which is an I / O port 110 and a RAM.
112, a CPU 114, and a ROM 116. These I / O port 110, RAM 112, CPU 11
4. The ROM 116 is connected by a bus 118.

The input side of the I / O port 110 is connected to the reflection type photosensor 148 and the colorimeter 144 of the colorimeter 34. The control unit 94 includes the density detection result obtained by the reflection type photo sensor 148 and the colorimeter 144.
Of the test image 102 is input.

Also, on the input side of the I / O port 110,
A pulse oscillator 154 that outputs a pulse signal of a predetermined frequency and is built in the control unit 94 is also connected.

On the output side of the I / O port 110, the transport roller 42, the motor 124, and the correction data creating unit 22 are connected.

The RAM 112 has a reflection type photo sensor 1
48 and the colorimetric result of the colorimeter 144 are stored as needed.

The ROM 116 stores the image receiving paper 40 for a predetermined length T.
Pulse oscillator 15 corresponding to the time required for one transport
4 (hereinafter, referred to as "predetermined pulse number") N1.

The ROM 116 stores the number of pulses N2 of the pulse generator 154 (hereinafter referred to as "predetermined pulse number") corresponding to the time required to move the colorimeter 144 by a predetermined length T2.

The test image 10 is stored in the ROM 116.
2 are stored.

In the ROM 116, the time when the reflection type photosensor 148 continues to detect the first reference line 104 when the first reference line 104 is inclined to the maximum allowable limit with respect to the image receiving paper 40 (hereinafter, referred to as "the time"). , “Predetermined time”) are also stored.

The CPU 114 controls the driving of the motor 124 to control the timing of starting the movement of the colorimeter 144 in the width direction and the movement distance. Further, the rotation speed of the motor 124 is controlled so that the moving speed of the colorimeter 144 is maintained at a predetermined speed. The transport distance of the image receiving paper 40 and the movement distance of the colorimeter 144 are grasped by counting the pulses oscillated by the pulse oscillator 154. The pulse count value is updated and stored in the RAM 112 as needed.

The CPU 114 controls the driving of the transport roller 42 to control the timing of starting and stopping the transport of the image receiving paper 40 and the transport distance. Further, the rotation speed of the transport roller 42 is controlled so that the transport speed of the image receiving paper 40 is maintained at a predetermined speed.

The CPU 114 obtains the lightness index L and the perceived chromaticity a and b in the Lab color system from the density measurement result of each patch 103 by the colorimeter 144,
To memorize. In addition, data of the lightness index L and the perceived chromaticity a and b (hereinafter, referred to as “colorimetric data”) are extracted in the order of measurement and transmitted to the correction data creating unit 22.

The CPU 114 determines whether the reflection type photosensor 148 has detected black based on the detection result (presence or absence of reflected light) by the reflection type photosensor 148, that is, the first reference line 104 or the second reference line. Line 106
It is determined whether or not is detected.

The CPU 114 controls the reflection type photo sensor 14
8, when the colorimeter 144 is moved in the width direction of the colorimeter 34 while the first reference line 104 is being detected, the reflection type photosensor 148 causes the first reference line 10 to move.
4 is measured. Further, the measured time is compared with a predetermined time stored in the ROM 116 to determine whether the inclination of the first reference line 104 with respect to the image receiving paper 40 is within the maximum allowable limit.

First reference line 10 with respect to image receiving paper 40
If the inclination of 4 is equal to or larger than the maximum allowable limit, it is determined that accurate calibration cannot be performed, and the calibration operation is stopped. In addition, an error message is displayed on the operation panel of the image forming apparatus 14 (not shown) and a warning sound is output.

Next, the operation of the embodiment of the present invention will be described.

First, the flow of the image forming process by the image forming apparatus 14 will be described.

In the image exposure apparatus 10, the photosensitive material 16 loaded in the photosensitive material loading section 18 is sent to the exposure unit 24 by driving a transport roller (not shown). The exposure unit 24 scans and exposes the photosensitive material 16 with a light beam based on the corrected image data. That is,
The exposure unit 24 is provided with an arc-shaped drum 78 having a center angle of about 180 °.
The light beam is irradiated onto the photosensitive material 16 from the inner circumferential direction of the drum 78.

The photosensitive material 16 is provided on a face portion 26 provided near the connection between the heat developing device 12 and the image exposing device 10.
The water is applied to the photosensitive material by a water application unit 80 belonging to the heat development unit 28, and is sent to the heat development drum 84.

The photosensitive material 16 conveyed along the outer peripheral surface of the heat developing drum 84 at a temperature suitable for the heat developing process.
Then, the image receiving paper 40 is heated for a predetermined time, and an image is formed on the image receiving paper 40.

The image receiving paper 4 is separated by the photosensitive material separating member 88.
The photosensitive material 16 that has been peeled off from the photosensitive material 16 is wound around the winding shaft 92 of the photosensitive material winding section 30, and is disposed as waste material. Further, the image receiving paper 40 is separated from the heat developing drum 84 by the image receiving paper separating member 90, passes through the colorimetric device 34, and is discharged to the outside of the heat developing device 12.

If the temperature of the heat developing drum 84 is uneven, the color of the image formed on the image receiving paper 40 by the image forming process also becomes uneven. In order to eliminate the color unevenness, the image forming apparatus 14 is provided with a calibration function. Next, the calibration process will be described.

When the user operates an operation panel (not shown) of the image forming apparatus 14 and selects the color measurement mode,
The image forming apparatus 14 starts a calibration process.

First, in the image exposure apparatus 10, the first reference line 104 and the second reference line 106 are stored together with the stored calibration test image (see FIG. 3) in the same manner as in the above-described image forming process. Is written on the photosensitive material 16.

Next, in the heat developing device 12, similarly to the above-described image forming process, the photosensitive material 16 and the image receiving paper 40 are moved along the outer peripheral surface of the heat developing drum 84 at a temperature suitable for the heat developing process. Transport. As a result, the photosensitive material 16 and the image receiving paper 40 are heated for a predetermined time, and the test image, the first reference line 104 and the second reference line 1
06 is formed.

The image receiving paper 4 is separated by the photosensitive material separating member 88.
The photosensitive material 16 that has been peeled off from the photosensitive material 16 is wound around the winding shaft 92 of the photosensitive material winding section 30, and is disposed as waste material. Further, the image receiving paper 40 is separated from the thermal developing drum 84 by the image receiving paper separating member 90, and is conveyed to the colorimetric device 34. The color measurement device 34 measures the color of the test image 102 formed on the image receiving paper 40, that is, the color of each patch 103.

Next, the colorimetric control performed by the colorimetric device 34 will be described with reference to the flowchart of FIG.

In step 300, it is determined whether or not the image receiving paper 40 has been inserted into the colorimetric device 34. When the insertion of the image receiving paper 40 is detected, the process proceeds to step 302. This determination means is not particularly limited. For example, a sensor for detecting the image receiving paper 40 may be provided near the insertion opening of the image receiving paper 40 (not shown) of the color measurement device 34, and the determination may be made based on the detection result by this sensor. . Further, since the image receiving paper 40 is conveyed in the apparatus at a predetermined speed, the time elapsed from the thermal development processing start timing is measured by the pulse oscillator 154, and after the predetermined time has elapsed, the image receiving paper 40 is inserted into the colorimetric device 34. May be determined.

In step 302, the motor 124 is driven to move the colorimeter 144 to the center position in the width direction of the image receiving paper 40 and set. The image receiving paper 40 is always conveyed at a predetermined speed even after being inserted into the colorimetric device 34. FIG. 9 shows the state of the colorimeter 144 and the image receiving paper 40 at this time.
As can be seen from FIG. 9, when the image receiving paper 40 is transported in the direction of the arrow B, the reflection type photosensor 148 attached to the colorimeter 144 moves substantially from the center in the width direction of the image receiving paper 40 from above. It will be measured by scanning down.

In step 304, the reflection type photo sensor 148 is set to the first type based on the detection result of the reflection type photo sensor 148, that is, whether or not the reflected light is detected.
It is determined whether or not the reference line 104 is detected. Here, when the reflected light is no longer detected by the reflective photosensor 148, it is determined that the first reference line 104 has been detected.

If a negative determination is made in step 304, the process returns to step 302. That is, the reflection type photosensor 1
48 until the first reference line 104 is detected.
The image receiving paper 40 is continuously transported at a predetermined speed.

Further, the first reference line 104 is detected by the reflection type photo sensor 148, and if an affirmative determination is made in step 304, the process proceeds to step 306.

In step 306, the conveyance of the image receiving paper 40 is stopped. Thus, the reflection type photo sensor 148 stops while detecting the first reference line 104.

In step 308, the colorimeter 144 is moved in parallel to the right end of the image receiving paper 40. At the same time, the pulses oscillated from the pulse oscillator 154 are counted,
The time during which the reflective photosensor 148 detects the first reference line 104 is measured. At this time, if the first reference line 104 is formed parallel to the width direction of the image receiving paper 40, the reflective photosensor 148 continues to detect the first reference line 104. The larger the inclination of the first reference line 104 with respect to the image receiving paper, the shorter the measured detection time.

In step 310, the time during which the reflective photosensor 148 detects the first reference line 104 (the time measured in step 308) is compared with a predetermined time stored in the ROM 116. Thus, it is determined whether or not the inclination of the first reference line 104 with respect to the image receiving paper 40, that is, the inclination of the test image 102 with respect to the image receiving paper 40 is within the maximum allowable limit.

If the measured time is smaller than the predetermined time, the first reference line 104 is inclined more than the maximum allowable limit, that is, the test image 102 is formed to be greatly inclined with respect to the image receiving paper 40. And step 3
It moves to 12. If the measured time is equal to or longer than the predetermined time, it is determined that the inclination of the first reference line 104 is within a predetermined range, and the process proceeds to step 314.

In step 312, if the test image 102 is formed on the image receiving paper 40 with a large inclination, it is impossible to associate the colorimetric position with the test image data stored in the correction data creating unit 22. Therefore, the calibration work is stopped. In addition, an error message indicating that normal calibration cannot be performed is displayed on an operation panel (not shown) of the image forming apparatus 14, and a warning sound is output. This prevents the execution of incorrect calibration.

In step 314, the pulse generator 154
The number of pulses oscillated from is counted and a predetermined number of pulses N
The image receiving paper 40 is conveyed at a predetermined speed until one pulse is oscillated. As a result, the image receiving paper 40 is transported by the predetermined length T1, and the colorimeter 144 is set at the upper end of the test image 102, which is the write start position of the test image data of the laser 46.

In step 316, the colorimeter 144 is moved from the right end to the left at a predetermined speed. The state of the colorimeter 144 and the image receiving paper 40 at this time is shown in FIG. As can be seen from FIG. 10, when the colorimeter 144 moves from right to left (in the direction of the arrow D) of the image receiving paper, the reflective photosensor 148 attached to the colorimeter 144 causes the image receiving paper 4 to move.
The measurement is performed by scanning the width direction of 0 from right to left.

In step 318, the reflection type photosensor 148 is turned on based on the detection result of the reflection type photosensor 148, that is, based on the presence or absence of the reflected light to be detected.
It is determined whether or not the reference line 104 is detected. Here, when the reflected light is no longer detected by the reflective photosensor 148, it is determined that the second reference line 104 has been detected.

If a negative determination is made in step 318, the process returns to step 316. That is, the reflection type photosensor 1
48 until the second reference line 106 is detected.
The colorimeter 144 continues to move at a predetermined speed.

Further, when the second reference line 106 is detected by the reflection type photo sensor, and the determination in step 318 is affirmative, the process proceeds to step 320.

In step 320, the pulse generator 154
The number of pulses oscillated from is counted and a predetermined number of pulses N
The colorimeter 144 is moved at a predetermined speed until two pulses are oscillated. As a result, the colorimeter 144 has a predetermined length T2.
Is moved, the colorimeter 144 is set at the right end of the test image 102 formed on the image receiving paper 40, so that the correspondence with the axial position of the heat developing drum 84 can be grasped.

When step 320 is completed, the colorimeter 14
Reference numeral 4 is set at the upper right end of the test image 102 on the image receiving paper 40. The color of the upper right corner of the test image 102 is
This corresponds to the data stored at the start address of the storage area of the test image data for calibration of the correction data creation unit 22. That is, the measurement position of the colorimeter 144 and the position data of the stored test image data have been aligned.

In step 322, the colorimeter 144 measures the color of the test image formed on the image receiving paper 40, that is, measures the color of each patch 103. In this color measurement, the colorimeter 144 is moved from right to left, the colorimeter 144 is stopped at the center of the rightmost patch 103, and the color of the patch 103 is measured. When the color measurement is completed, the colorimeter 144 is moved to the center of the patch 103 on the left (in this embodiment, about 2
0 mm), the color of the patch 103 is measured. In this manner, the colorimeter 144 is repeatedly moved, stopped, measured, and then moved, and the color measurement of each upper patch 103 is performed again.

When the color measurement of the upper patch 103 is completed, the image receiving paper 40 is finely conveyed by the length of the patch 103, and the colorimeter 144 is returned to the right end of the test image 102. Thereafter, the colorimeter 144 is again moved from right to left, stopped, measured, moved, and so on, and the color measurement of the next patch 103 is performed. By repeating such an operation, the colors of all the patches 103 of the test image formed on the image receiving paper 40 are measured.

At this time, since the curl of the image receiving paper 40 is extended by the bearing 150 and the colorimeter 144 is moved following the bending of the base plate 152, the measurement distance H is always measured.
Can be measured at a predetermined value.

The colorimetric result of each patch 103 is converted by the control unit 94 into a lightness index L and perceived chromaticity a and b in the Lab color system, and transmitted to the correction data creating unit 22 as colorimetric data.

In step 324, it is determined whether or not the image receiving paper 40 has been conveyed by the vertical length of the test image 102 since the color measurement in step 322 was started. That is, it is determined whether the color measurement of all the patches 103 has been completed.

If the color measurement of all the patches 103 has not been completed (No at Step 324), Step 3
Returning to 16, color measurement is continued.

When the color measurement of all the patches 103 is completed (Yes at step 324), the processing by the colorimetric device 34 is completed.

When the color measurement is completed, the image receiving paper 40 on which the calibration test image has been formed is transferred to the heat developing device 1.
2 to the outside.

The correction data generator 22 compares the colorimetric data sent with test image data for calibration stored in advance to determine a color shift. Note that this color shift is obtained by the calculation of ΔE = (ΔL ² + Δa ² + Δb ² ) ^1/2 (ΔE is the color shift, ΔL, Δa, Δ
b is the difference between the colorimetric data and the target value obtained in advance based on the test image data).

Further, the correction data creating section 22 creates spatial correction data so as to eliminate the obtained color shift.

When the correction data has been created, the image forming apparatus 14 automatically shifts to the image forming processing mode. In the subsequent image forming process, the correction circuit 20 spatially corrects the desired image data with the correction data to generate corrected image data. A light beam is irradiated on the photosensitive material 16 based on the corrected image data to perform an image forming process.

As described above, in the present embodiment, the first reference line 104 and the second reference line 106 for specifying the formation position of the test image 102 on the image receiving paper 40 are formed together with the test image 102. The photosensitive material 16 is exposed and written. By detecting the first reference line 104 and the second reference line 106 formed on the image receiving paper 40 by the reflection type photo sensor 148, the colorimetric device 34 is detected.
In, the formation position of the test image 102 is automatically grasped.
Thereby, the test image data stored in advance,
The position measured by the colorimeter 144 can be accurately associated.

Further, by incorporating the colorimetric device 34 into the image forming apparatus 14, a series of operations required for calibration can be automated, and light outside the apparatus can be blocked, so that the influence of external light can be reduced. Color can be accurately measured without receiving it.

If the test image 102 formed on the image receiving paper 40 is greatly inclined, an error is output and the processing is terminated, so that it is possible to prevent the execution of incorrect calibration.

Further, the casing 14 is
By supporting 0, the measurement distance H between the measurement surface of the colorimeter 144 and the image receiving paper 40 is maintained at a predetermined value. The casing 140 is supported at three points by bearings 150,
It is supported stably. Thereby, the casing 140 can be moved naturally following the bending of the base plate 52 and the change in the thickness of the image receiving paper 40, and the measuring distance H can be automatically adjusted without using an expensive computer. Colorimetry can be performed while maintaining a predetermined value.

In this embodiment, the casing 14
1 is located at both ends of one side of the colorimeter 34 which is parallel to the width direction.
One bearing 150 at the center of the facing side
However, if the colorimeter 144 can be stably maintained, the mounting position and the number are not limited thereto.

For example, as shown in FIG. 11, one bearing 150 is attached to the center of the casing 140 at the front (the scanning direction of the colorimeter 144 shown by the arrow D is forward), and one at the rear end. You may.

As shown in FIG. 12, the distance (span) between the bearings 150 may be shortened. FIG. 13 (A) shows a case where color measurement is performed on a flat base plate 152, and FIG. 13 (B) shows a case where color measurement is performed by a color measurement device 34 having a long span of a bearing 150 on a base plate 152 having a curved surface. C) shows the respective measurement distances H when the colorimetric device 34 having a short span of the bearing 150 performs colorimetry.

As can be seen from FIG.
The shorter the span of 50, the case where the base plate 152 is flat,
The change of the measurement distance H from the case where the vehicle is bent is small. That is, the shorter the span of the bearing 150 is attached, the better it follows the bending of the base plate 152, and a highly accurate measurement can be performed.

Although the metal bearing 150 is used to support the casing 140 and move it on the image receiving paper 40, the present invention is not limited to this. When there is a concern that the surface of the image receiving paper 40 may be damaged, a bearing or a roller made of a material such as resin or rubber may be used. May be covered.

The bearing 150 is used to support the casing 140 while maintaining the measurement distance H at a predetermined value, but the invention is not limited to this. For example, as shown in FIG.
Alternatively, a protrusion 160 protruding from the fourth measurement unit 144A may be formed. As shown in FIG. 14B, a support member 162 may be attached to the bottom of the casing 140 so as to protrude from the measurement section 144A of the colorimeter 144.

A colorimetric device 34 for using the colorimetric device of the present invention at the time of calibration in the image forming apparatus 14.
, But is not limited to this. The present invention can be applied to any apparatus that scans the surface of an object and measures the color and density of the object.

The mechanism for scanning on the surface of the object may be applied to an apparatus for inputting or recording information by scanning an input sensor or a recording light source. For example, the present invention can be applied to a hand scanner or the like that inputs image information by operating an input sensor such as a CCD. Further, the present invention can also be applied to a device that records information by scanning a recording medium surface with a recording light source such as an LED or a laser and irradiating the recording medium surface with light.

[0126]

As described above, the present invention has a mechanism which can be realized at low cost and which automatically keeps the distance between the measurement surface for measuring color or density and the object to be measured constant. A colorimeter capable of measuring high color or density can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an internal configuration of an image forming apparatus according to an embodiment.

FIG. 2 is a configuration diagram illustrating a detailed configuration of a heat development device according to the exemplary embodiment.

FIG. 3 is a schematic diagram of a test image for calibration formed on an image receiving sheet.

FIG. 4 is a schematic sectional view of a colorimeter.

FIG. 5 is a schematic side view of the color measurement device.

FIG. 6 is a schematic bottom view of the color measuring device.

FIG. 7 is a block diagram of a control unit that controls the operation of the colorimetric device.

FIG. 8 is a flowchart illustrating a calibration control routine.

FIG. 9 is a schematic top view of the color measurement device schematically showing a state of the color measurement device when detecting the first reference line.

FIG. 10 is a schematic top view of the color measurement device schematically showing a state of the color measurement device when detecting the second reference line.

FIG. 11 is a schematic diagram showing an example of the arrangement of bearings in another embodiment.

FIG. 12 is a schematic diagram showing an example of the arrangement of bearings in another embodiment.

FIG. 13 is a schematic diagram showing a measurement distance at the time of color measurement by a color measurement device, where (A) shows a case where color measurement is performed on a flat base plate;
(B) is a colorimeter with a long bearing span on a curved plate, and (C) is a colorimetric device with a short bearing span on a curved plate. Indicates the measurement distance when coloring.

14A and 14B are schematic diagrams of a color measurement device according to another embodiment, in which FIG. 14A is a schematic cross-sectional view of the color measurement device when a projection is formed on the bottom surface of a casing, and FIG. FIG. 1 shows a schematic side view of a colorimetric device when a support member is attached to FIG.

15A and 15B show a schematic configuration of a conventional colorimeter, in which FIG. 15A is a schematic perspective view, and FIG. 15B is a schematic side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Image exposure apparatus 12 Thermal developing apparatus 14 Image forming apparatus 34 Colorimeter 40 Image receiving paper (object of colorimetry) 124 Motor (transportation means) 140 Casing (body) 144 Colorimeter (measurement instrument) 150 Bearing (supporting means, Roller) 160 Supporting member (supporting means) 162 Projection (supporting means)

Claims (3)

[Claims] 1. While scanning a surface to be measured of an object to be measured,
A colorimeter for measuring density or color, comprising: a measuring device provided on a vehicle body with a measurement surface for measuring density or color facing the object to be measured; and a distance between the measurement surface and the surface to be measured. A supporting means for projecting from the vehicle body toward the surface to be measured so as to keep the dimensions constant, and supporting means for supporting the vehicle body on the object to be measured; and Transport means for transporting the vehicle body on the object to be measured while maintaining the vehicle body. 2. The colorimetric apparatus according to claim 1, wherein said support means is a roller, and is rotated by the transport of said transport means to transport the vehicle body. 3. The colorimetric device according to claim 2, wherein the vehicle body is provided with three of the rollers and supported at three points.