JP2000241248A - 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: A colorimeter 144 is supported by a conveyance block 138 in contact with neither a base plate 152 nor image receiving paper 40. A suspension bracket 134 fitted to the top surface of the colorimeter 144 is guided into the conveyance block 138 and a push-down part 154 projects from the conveyance block 138. A lever 156 arranged above the conveyance block 138 is driven by a motor 168 to rotate, thereby pressing down the push-down part 154. This depression makes a compressed coil spring 132 shrink and the colorimeter 144 moves toward the image receiving paper 40 to press the reverse surface of a color 124 against the image receiving paper 40. Consequently, the measurement distance is held constant.

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. 17 shows a schematic configuration of a conventional colorimeter.

As shown in FIG. 17, 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 H. 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 instrument 202 (arrow H), 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 conveying roller pair 208, and is conveyed in the direction of the conveying roller 210 (the direction shown by arrow I). 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 mounted with a light receiving surface for measuring a light amount corresponding to a density or a color facing the measurement object, and moving the measurement device and the measurement object in a direction approaching each other; Moving means for bringing the measurement object into contact with the measurement reference surface, which always maintains a predetermined distance from the light receiving surface, and holding means for keeping the contact pressure between the measurement reference surface and the measurement object constant And transport means for transporting the measuring instrument on the measurement object while bringing the measurement reference surface into contact with the measurement object by the moving means.

According to the first aspect of the present invention, a colorimetric device includes a measuring device, a moving unit, and a transporting unit. A light receiving surface (e.g., a measuring surface of a CCD) for measuring the amount of light according to the density or color of the measuring device is installed so as to face the measuring object, and the measuring device measures the density or the density of the measuring surface of the measuring object. Measure the color. The moving means moves the measuring instrument and the object to be measured so as to approach each other. In addition, the moving unit makes a measurement reference surface, which is provided for maintaining a predetermined distance from the light receiving surface of the measuring device, contact with the measurement object. At this time, the contact pressure between the measurement reference plane and the measurement object is
It is kept constant by the holding means. By this contact, the distance dimension (measurement distance) between the light receiving surface of the measuring instrument and the surface to be measured of the measurement object is kept constant. The transport unit transports the measuring device on the measurement target. This transfer is performed while the moving reference unit is in contact with the measurement reference plane, the object to be measured, and the surface to be measured. 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 moving means has a structure for moving the measuring instrument, and the holding means supports the measuring instrument via an urging force. Are characterized by

According to the second aspect of the present invention, the moving means moves the measuring device in the direction of the object to be measured, and brings the measurement reference plane into contact with the object to be measured. Further, the holding means supports the measuring instrument via the urging force. Due to the action of this urging force, even if the distance between the measurement reference plane and the measurement object changes while the measuring device is being conveyed by the conveyance means, the measurement reference plane and the measurement object are automatically responded to the change. The instrument can be supported to maintain contact with the instrument.

According to a third aspect of the present invention, in the first aspect of the present invention, the moving means is configured to move the object to be measured, and the holding means supports the object to be measured via an urging force. Are characterized by

According to the third aspect of the present invention, the moving means moves the object to be measured in the direction of the measuring instrument, and brings the measurement reference plane into contact with the object to be measured. The holding means supports the object to be measured via the urging force. Due to the action of this urging force, even if the distance between the measurement reference plane and the measurement object changes while the measuring device is being conveyed by the conveyance means, the measurement reference plane and the measurement object are automatically responded to the change. The object to be measured can be supported so as to keep the contact of the object.

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 the 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.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Next, an example of an embodiment according to the present invention will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to a colorimetric device used for calibration of an image forming apparatus. FIG. 1 shows an image forming apparatus 14 provided with the colorimetric device.

As shown in FIG. 1, the image forming apparatus 14
Is composed of an image exposure device 10 and a heat development 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 creation unit 22 stores test image data for calibration. Therefore, the correction data creation unit 22
Creates correction data to be used when the correction circuit 20 corrects the image data from the stored test image data and the detection (measurement) data by the temperature and humidity sensor 36 and the colorimetric device 34.

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 colorimetric 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 heat 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 thermal 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 color is measured. 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 color measuring device 34 is discharged to the outside of the heat developing device 12.

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 printing 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 perspective view of the colorimeter 34.

As shown in FIGS. 4, 5, and 6, the colorimetric device 34 includes a base plate 152, a colorimeter 144,
38 and a lever 156.

The base plate 152 of the colorimetric device 34 is provided with side walls 120A and 120B at both ends in the width direction (the direction indicated by the arrow C in FIG. 4) of the colorimetric device 34. Further, a side wall cover 174 is attached to the side wall 120A.

The image receiving paper 40 is guided on the base plate 152 with the surface on which the test image is formed facing upward, and is transported between the side walls 120A and 120B. The direction in which the image receiving paper 40 is transported is indicated by an arrow B in FIG.

A colorimeter 144 for measuring a color is provided above the base plate 152. FIG. 7 shows a schematic configuration of the colorimeter 144. As shown in FIG. 7, the colorimeter 144 has an image formed on the image receiving paper 40 guided on the base plate 152 (that is, below the colorimeter 144), with the center of the bottom surface serving as the measurement surface 122. Measure the color. The colorimeter 14
In No. 4, light is irradiated onto the image receiving paper 40, and the reflected light is detected (a so-called spectral tristimulus value is detected). Based on the detection result, the lightness index L in the Lab color system, the perceived chromaticity a, b
Is measured to determine the chromaticity.

The measurement surface 122 is covered on the sides by a cover 124 formed in a tapered shape. The surface of the cover 124 facing the measurement surface 122, that is, the bottom surface of the cover 124 is open so as not to hinder color measurement of the image receiving paper 40 guided on the base plate 152. The cover 124 allows the measurement surface 1 of the colorimeter 144 to be measured.
22 and the distance between the image receiving paper 40 as an object to be measured (hereinafter referred to as a distance).
The “measurement distance” is kept at the distance between the measurement surface 122 and the bottom surface of the cover 124 even when the distance is closest. That is, the bottom surface of the cover 124 corresponds to the measurement reference plane BS of the present invention.

The cover 124 is made of a material having a small coefficient of friction such as glass or plastic.
The bottom is chamfered. Thereby, the cover 1
24 can move smoothly (substantially without being affected by friction) even when it comes into contact with the image receiving paper 40.

On the upper surface of the colorimeter 144, a suspension bracket is mounted. The suspension bracket 134 is formed by bending a flat plate into a substantially U-shape, and its longitudinal ends (lower ends) are bent at right angles in directions away from each other to form a flange portion 136. The flange 136 and the upper surface of the colorimeter 144 are fixed with bolts.

Further, bearings 126 are attached to both ends in the width direction of the colorimeter 34 of the colorimeter 144, respectively. A compression coil spring 132 is provided on the lower surface of the bearing 126.
Is attached at one end. This compression coil spring 1
A guide rod 130 is guided in the cavity inside 32. The center of the guide rod 130 is loosely fitted to the bearing 126. At one end (lower end) of the guide rod 130,
A large-diameter flange portion 128 is integrally formed. The other end of the compression coil spring 132 is attached to the flange 128. That is, the colorimeter 144 is supported by the repulsive force of the compression coil spring 132. The colorimeter 144 can be moved up and down by the expansion and contraction of the compression coil spring 132,
Since it becomes a core, it is stably supported without tilting.

The other end (upper end) of the guide rod 130
Is fixed to the lower end surface of the transport block 138 disposed above the colorimeter 144. Transport block 138
The guide rod 130 is suspended and supported so that the flange portion 136 of the guide rod 130 does not contact the base plate 152 or the image receiving paper 40. In addition, usually, the bottom surface of the cover 124 does not contact the base plate 152 or the image receiving paper 40,
The colorimeter 144 is also suspended and supported by the transport block 138.

One end of the center of the transport block 138 is cut into a rectangle in the longitudinal direction (the width direction of the colorimetric device 34), and the guide shaft 140 is guided. Both ends of the guide shaft 140 are parallel to the upper surface of the base plate 152 so that the side walls 120A and 120B of the colorimetric device 34 are parallel to each other.
It is fixed to.

The other end of the center of the transport block 138 is hollowed into a cylindrical shape, and a female screw is formed at the center in the width direction of the hollowed portion as shown in FIG.
A shaft (hereinafter, referred to as “drive shaft”) 142 on which a male screw corresponding to the female screw is formed is guided.

The drive shaft 142 extends between the side walls 120A and 120B in parallel with the guide shaft 140 and in the direction of conveyance of the image receiving paper 40. One end (the right end in FIG. 4) of the drive shaft 142 protrudes outside the side wall 120, and the end protruding outside the side wall 120 is mounted on the gear 146. Gear 1
Below the gear 46, the gear 14 is engaged with the gear 146.
8 are provided. The gear 148 is provided on the side wall cover 17.
4 is mounted on a motor 150 attached to the motor. That is, the gear 148 is rotated by the driving of the motor 150, and the gear 146 is rotated by the rotation of the gear 148, and the drive shaft 142 is rotated. Transport block 1
38 moves in the direction of arrow E in response to the rotation of the drive shaft 142. That is, by controlling the driving of the motor 150, the colorimeter 144 can be moved in the direction of the arrow E. In addition, since this movement is performed by being supported by the guide shaft 140, the movement is stable without tilting.

The colorimeter 144 of the transport block 138
The center portion in the width direction and the center portion in the transport direction of the image receiving paper 40 are rectangularly hollowed from the upper surface to the lower surface, and the above-described hanging bracket 134 is guided. The upper surface of the suspension bracket 134 (hereinafter, referred to as a “pressing portion”)
Reference numeral 154 projects from the upper surface of the transport block. The push-down unit 154 is connected to the transport block 138.
Is depressed by a lever 156 disposed above.

As shown in FIG. 9, the lever 156 is composed of a bottom plate 158 that comes into contact with the press-down portion 154, and a wall plate 160 formed by bending a flat plate into a substantially U-shape. The lower end of the wall plate 160 is fixed to the bottom plate 158, and the side walls 160A and 160B and the rear wall 160C at both ends in the longitudinal direction (the width direction of the colorimetric device 34) of the lever 156.
It has become. Shaft guide holes 162A and 162B are formed in the central portions of the side walls 160A and 160B, respectively.

The shaft guide hole 162B has a flange integrally formed at one end thereof, and the other end of the rotation guide shaft 172 penetrating from the outside of the side wall 120B is fitted and fixed. The central portion of the rotation guide shaft 172 is loosely fitted to a bearing 166B fitted to the side wall 120.

One end of the rotating shaft 164 is fitted and fixed to the shaft guide hole 162A. A central portion of the rotating shaft 164 is loosely fitted to a bearing 166 fitted to the side wall 120 and protrudes outside the side wall 120. The other end of the rotating shaft 164 is mounted on a torque limiter 170. Torque limiter 170
Denotes a motor 168 attached to the side wall cover 174.
Is mounted on the rotating shaft. The torque limiter 170 is
The driving force of the motor 168 having a predetermined torque or more is not transmitted to the rotating shaft 164.

Thus, when the motor 168 is driven,
The rotation shaft 164 rotates, and the lever 156 moves to the side wall 16.
It rotates in the direction of arrow F with the center of 0A and 160B as the center of rotation. By the rotation of the lever 156, the above-described press-down unit 154 is pressed down, and the colorimeter 144 moves in the direction of the image receiving paper 40 guided on the base plate 152.

Further, the bottom surface of the cover 124 of the colorimeter 144 comes into contact with the image receiving paper 40 and receives a drag from the image receiving paper 40 (base plate 152). As a result, the driving force of the motor 168 required to rotate the lever 156 is required in addition to the compression coil spring, and when the driving force of the motor 168 exceeds a predetermined torque, the torque limiter 170 operates to activate the motor 168. Spin idle. As a result, the rotation of the lever 156 stops. That is, by the torque limiter 170,
The contact of the cover 124 with the image receiving paper 40 is automatically detected, and the contact state can be maintained.

Further, if the resistance of the colorimeter 144 changes due to bending of the base plate 152 such as unevenness or curvature, or a change in the thickness of the image receiving paper 40, a change in the resistance is caused by the urging force of the compression coil spring 132. The colorimeter 144 moves in the direction of the arrow F (vertical direction) so as to eliminate the cover, and the cover 124 always comes into contact with the image receiving paper 40 with a constant pressing force. That is, due to the contraction of the compression coil spring 132, the bending of the base plate 152 in the direction of arrow F (vertical direction) such as unevenness or curvature, and the change in the thickness of the image receiving paper 40 are absorbed. This allows
The colorimeter 144 moves following the bending of the base plate 152 and the change in the thickness of the image receiving paper 40, and the measurement distance can be kept constant.

Incidentally, the motor 150 of the colorimetric device 34,
The driving of 168 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 composed of an I / O port 110, 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 above-mentioned colorimeter 144 is connected to the input side of the I / O port 110, and the colorimetric result of the colorimeter 144 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 motors 150 and 168, the correction data generator 2
2 are connected.

The RAM 112 stores the result of the color measurement by the colorimeter 144 as needed.

The ROM 116 stores the image receiving paper 40 with 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 oscillator 154 (hereinafter, referred to as "predetermined pulse number") corresponding to the time required to move the colorimeter 144 by the predetermined length T2.

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

The ROM 116 stores a time (hereinafter, referred to as a time) during which the colorimeter 144 continues to detect the first reference line 104 when the first reference line 104 is inclined at the maximum allowable limit with respect to the image receiving paper 40. "Predetermined time" is also stored.

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 controls the driving of the motor 150 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 150 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 determined by counting the pulses oscillated by the pulse generator 154. The pulse count value is updated and stored in the RAM 112 as needed.

The CPU 114 controls the driving of the motor 168 to control the movement of the colorimeter 144 in the direction of the image receiving paper 40 (vertical direction).

The CPU 114 converts the measurement result of the colorimeter 144 into 8-bit colorimetric data for each of the RGB components. Also, the colorimetric data for a plurality of lines obtained by one scanning is stored in the RAM 112. The colorimetric data is extracted for each line in the order of RGB and output to the correction data creating unit 22.

When the colorimeter 144 measures (detects) black, the CPU 114 sets the first reference line 104
Alternatively, it is determined that the second reference line 106 has been detected in a predetermined manner.

The CPU 114 operates the first reference line 104 when the colorimeter 144 is moved in the width direction of the colorimeter 34 while the colorimeter 144 is detecting the first reference line 104. Measure the time to keep detecting. Further, the measured time is compared with a predetermined time stored in ROM 116. If the measured inclination 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 first embodiment will be described.

First, the flow of image forming processing 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 26 provided near a 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 colorimeter 34 measures the color of the test image formed on the image receiving paper 40, that is, the color of the test image 102.

FIG. 11 shows a color measurement routine performed by the color measurement device 34.
This 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. The determination means is not particularly limited. For example, a sensor for detecting the image receiving paper 40 is provided near the insertion opening of the image receiving paper 40 (not shown) of the colorimetric device 34, and the determination is performed based on the detection result by this sensor. Is also good. 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 150 is driven to move the colorimeter 144 to the center position in the width direction of the image receiving paper 40 and set.

Next, at step 304, the motor 16
8 is driven, the lever 156 is rotated in the F direction, and the colorimeter 144 is moved in the direction of the image receiving paper 40 (downward).
When the cover 124 of the colorimeter 144 contacts the image receiving paper 40, the torque limiter 170 operates, and the motor 168 runs idle. Thus, the rotation of the lever 156 is stopped, and the state in which the cover 124 is in contact with the image receiving paper 40 is maintained.
Note that the subsequent processing is performed in this state. That is,
When the measurement distance is such that the measurement surface 122 of the colorimeter 144
Is kept constant in the state closest to.

The image receiving paper 40 is always conveyed at a predetermined speed even after being inserted into the colorimetric device 34. 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. 12, when the image receiving paper 40 is transported in the direction of arrow B, the colorimeter 144 scans the center of the image receiving paper 40 in the width direction from top to bottom for measurement. become.

The first reference line 10 is measured by the colorimeter 144.
When 4 is measured (detected), the process proceeds to step 308 (step 306).

In step 308, the conveyance of the image receiving paper 40 is stopped. As a result, the colorimeter 144 stops while detecting the first reference line 104.

In step 310, the motor 150 is driven to move the colorimeter 144 in parallel to the right end of the image receiving paper 40. At the same time, the time during which the colorimeter 144 detects the first reference line 104 is measured by counting the pulses oscillated by the pulse oscillator 154. At this time, if the first reference line 104 is formed parallel to the width direction of the image receiving paper 40, the colorimeter 144 continues to detect the first reference line 104. First reference line 1
The larger the inclination of the sheet 04 with respect to the image receiving paper, the shorter the measured detection time.

In step 312, the colorimeter 144
Time when the reference line 104 was detected and the ROM 116
Are compared with each other for a predetermined time. Thereby, the first
Of the reference line 104 with respect to the image receiving paper 40, that is, whether or not 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
Go to 14. 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 316.

In step 314, the test image 102 is formed to be inclined with respect to the image receiving paper 40 by the maximum allowable limit or more, and the colorimetric position is associated with the test image data stored in the correction data creating unit 22. Since calibration is not possible, 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 allows
Incorrect calibration execution is prevented.

In step 316, 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.

At step 318, the motor 150 is driven to move the colorimeter 144 from the right end to the left at a predetermined speed. FIG. 13 shows the state of the colorimeter 144 and the image receiving paper 40 at this time. As can be seen from FIG. 13, when the colorimeter 144 moves from right to left (the direction of arrow E) of the image receiving paper, the colorimeter 144 scans the width direction of the image receiving paper 40 from right to left. Will be measured.

In step 320, it is determined whether or not the second reference line 106 has been detected by the colorimeter 144.

If a negative determination is made in step 320, the process returns to step 318. That is, until the second reference line 106 is detected by the colorimeter 144,
Keeps moving at a predetermined speed.

When the second reference line 106 is detected by the colorimeter 144, an affirmative determination is made in step 320 and the process proceeds to step 322.

In step 322, the pulse generator 154
The number of pulses oscillated from is counted and a predetermined number of pulses N
Until the second pulse is oscillated, the motor 150 is driven to move the colorimeter 144 at a predetermined speed. As a result, the colorimeter 144 is moved by the predetermined length T2, and the colorimeter 144 is set at the right end of the test image 102 formed on the image receiving paper 40. You will be able to understand the response.

When Step 322 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 324, 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 measurement, first,
The colorimeter 144 is moved from right to left, and the rightmost patch 10
The colorimeter 144 is stopped at the center of 3 and the color of the patch 103 is measured. When the color measurement of this patch 103 is completed,
The colorimeter 144 is moved to the center of the patch 103 on the left (approximately 20 mm in the present embodiment), and the color of the patch 103 is measured. In this way, the movement of the colorimeter 144 → stop → colorimetry → movement...
03 color measurements are made.

When the color measurement of the uppermost 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 position of the right end of the test image 102. After that, the colorimeter 144 is again moved from right to left → stop → colorimetry → move..., 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 102 formed on the image receiving paper 40 are measured.

During this measurement, the cover 124 is
The colorimeter 144 is moved in the direction of arrow F (up and down) by the urging force of the compression coil spring 132 even if the base plate 152 is bent or the thickness of the image receiving paper 40 is changed. And the measurement distance during the measurement is always kept constant.

The colorimetric result is converted into a lightness index L in the Lab color system and perceived chromaticities a and b in the control unit 94 and transmitted to the correction data creating unit 22 as colorimetric data.

In step 326, 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 324 was started. That is, it is determined whether or not the color measurement of all the patches 103 of the test image 102 has been completed.

If the color measurement of all the patches 103 has not been completed (No in step 326), the process proceeds to step 3
Returning to 24, the color measurement continues.

When the colorimetry of the entire area of the test image 102 is completed (Yes in step 326), the colorimetric device 3
4 ends. When the colorimetric processing is completed, the motor 168 is driven to move the lever 156 in the direction opposite to the image receiving paper 40 (upward). Thereby, the colorimeter 1
44 moves upward and separates from the image receiving paper 40.

When the colorimetry 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 creating section 22 compares the sent colorimetric data with calibration test image data stored in advance to determine a color shift. The color shift is ΔE = (ΔL ²
+ Δa ² + Δb ² ) ^1/2 (ΔE is a color shift, ΔL, Δa, and Δb are differences between colorimetric data and target values previously obtained based on test image data, respectively).

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

After 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 first embodiment, when the colorimeter 144 is moved by the lever 156 and pressed against the image receiving paper 40, that is, when the cover 124 is in contact with the image receiving paper 40, the test image 102 The color is measured. As a result, the measurement distance is kept constant (the distance between the measurement surface 122 and the bottom surface of the cover 124), and colorimetry is performed.

Further, the colorimeter 144 is used for the compression coil spring 13.
2, and moves following the bending of the base plate 152 and the change in the thickness of the image receiving paper 40, so that the colorimetry is performed while keeping the measurement distance constant. Further, the motor 168 is attached to the side wall cover 174, and the lever 156 and the colorimeter 1 are mounted.
By dividing the motor 44 from the motor harness that requires an expensive rocket cable or the like, a normal harness can be used.

In the first embodiment, the lever 15
6, the colorimeter 144 is moved in the direction of the image receiving paper. However, the present invention is not limited to this, and any mechanism that moves the colorimeter 144 in the direction of the image receiving paper may be used.

(Second Embodiment) In the first embodiment, the cover 12 is moved by moving the colorimeter 144.
4 was brought into contact with the image receiving paper 40 to keep the measurement distance constant, but it is not limited to this. For example, the base plate 152
May be moved to bring the cover 124 into contact with the image receiving paper 40 so that the measurement distance is kept constant. An example is shown in FIG. The same members as those in FIGS. 5, 6, 7, and 8 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 14, guide rods 180 are loosely fitted to both ends of the base plate 152. Guide rod 18
One end (upper end) of O is fixed to a support base 182 attached to the side walls 120A and 120B. The other end (lower end) of the guide rod 180 has a large-diameter flange 18.
4 are integrally formed. Base plate 152 of guide rod 180
The lower portion is guided to a hollow portion inside the compression coil spring 186, and one end (lower end) of the compression coil spring is attached to the flange portion 184. That is, the base plate 152 is supported by the urging force of the compression coil spring 186, and can be moved in the direction of the arrow G (up and down direction) by expansion and contraction of the compression coil spring 186.

An eccentric cam 188 is provided below each flange 184. The eccentric cam 188 is attached to the rotating shaft 190. At one end of the rotating shaft, a torque limiter 189 is axially mounted. The torque limiter 189 is axially mounted on a rotating shaft of a motor 192 mounted outside the side wall cover 174.
The torque limiter 19 includes a motor 192 having a predetermined torque or more.
Is not transmitted to the rotating shaft 190.

As a result, by driving the motor 192,
The rotation shaft 190 rotates, and the eccentric cam 188 rotates. When the eccentric cam 188 rotates in contact with the flange 184, an upward force is applied to the flange 184, the base plate 152 moves in the direction of arrow G, and the image receiving paper 40 guided on the base plate 152 is moved. Cover 12 of colorimeter 144
4. The image receiving paper 40 comes into contact with the cover 124, and the compression coil spring 186 is further contracted, so that the eccentric cam 1
When the driving force of the motor 192 necessary for rotating the motor 88 exceeds a predetermined torque, the torque limiter 189 works to cause the motor 192 to run idle, and the rotation of the eccentric cam 188 stops. That is, the torque limiter 170 automatically detects that the cover 124 has contacted the image receiving paper 40,
The contact state can be maintained.

Further, when the resistance of the base plate 152 received from the colorimeter 144 changes due to the bending of the base plate 152 such as unevenness or curvature, or the change in the thickness of the image receiving paper 40, the biasing force of the compression coil spring 186 causes The base plate 152 moves in the direction of arrow G (vertical direction) so as to eliminate the change in the drag. That is, due to the contraction of the compression coil spring 186, bending of the base plate 152 in the direction of arrow G (vertical direction) such as unevenness or curvature, and changes in the thickness of the image receiving paper 40 are absorbed. This allows
The base plate 152 moves following the bending of the base plate 152 and the change in the thickness of the image receiving paper 40, and the measurement distance can be kept constant.

As shown in FIG. 15, the motor 192 of the colorimetric device 34 is driven by the motor 1 of the first embodiment.
Control is performed by the control unit 94 in the same manner as 68.
The description is omitted here.

Next, the operation of the second embodiment 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 the same calibration processing as in the first embodiment. In the colorimetric device 34,
Similar to the first embodiment, the processing shown in the color measurement routine of FIG. 11 is performed. Hereinafter, a color measurement routine performed by the color measurement device 34 will be described with reference to 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. The determination means is not particularly limited. For example, a sensor for detecting the image receiving paper 40 is provided near the insertion opening of the image receiving paper 40 (not shown) of the colorimetric device 34, and the determination is performed based on the detection result by this sensor. Is also good. 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 150 is driven to move and set the colorimeter 144 to the center position in the width direction of the image receiving paper 40.

Next, at step 304, the motor 19
2 is driven, and the eccentric cam 188 rotates. As a result, the base plate 152 moves in the direction of the colorimeter 144 (arrow G in FIG.
(In the direction shown in FIG. 5), the image receiving paper 40 guided on the base plate 152 comes into contact with the cover 124 of the colorimeter 144. Thereafter, this contact state is maintained and the same processing as in the first embodiment is performed (description is omitted).

As described above, in the second embodiment, the base plate 152 is moved by the eccentric cam 188 and the image receiving paper 40 is pressed against the cover 124 of the colorimeter 144, that is, the cover 124 is Test image 1 in contact with
The color 02 is measured. As a result, the measurement distance is kept constant (the distance between the measurement surface 122 and the lower surface of the cover 124), and colorimetry is performed. Further, the base plate 152 is supported by the compression coil spring 186 such that the image receiving paper 40 comes into contact with the cover 124, so that the surface of the base plate 152 may be bent,
The base plate 152 moves in the direction of the arrow G (up and down) following the change in the thickness of the image receiving paper 40, so that the measurement distance is kept constant and colorimetry is performed.

In the second embodiment, the eccentric cam 1
The image receiving paper 4 is moved by moving the base plate 152 with 88.
Although 0 is moved in the direction of the colorimeter 144, the present invention is not limited to this, and any mechanism that moves the image receiving paper in the direction of the colorimeter may be used.

In the first and second embodiments, the colorimeter 1 is used to keep the measurement distance constant.
Although the cover 124 is attached to the measurement surface 122 of 44 and the lower surface of the cover 124 is used as a measurement reference surface and the color is measured by contacting the image receiving paper 40, the invention is not limited to this. For example, FIG.
As shown in FIG. 6, a roller 176 may be provided on the colorimeter 144 so as to protrude in the direction of the image receiving paper 40, and the measurement distance may be kept constant by bringing the roller 176 into contact with the image receiving paper 40. Further, by providing the rollers 176, the movement in the direction of the arrow E can be performed more smoothly.

A colorimetric device 34 for utilizing 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.

Further, 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.

[0136]

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 first and second embodiments.

FIG. 2 is a configuration diagram illustrating a detailed configuration of a heat development device according to first and second embodiments.

FIG. 3 is a schematic diagram of a calibration test image formed on an image receiving sheet according to the first and second embodiments.

FIG. 4 is a schematic sectional view of the colorimetric device according to the first embodiment.

FIG. 5 is a schematic side view of the color measurement device according to the first embodiment.

FIG. 6 is a schematic perspective view of the color measurement device according to the first embodiment.

FIG. 7 shows a schematic configuration of a colorimeter of the colorimeter according to the first embodiment, and FIG. 7A is a schematic sectional view of the colorimeter;
(B) is a schematic perspective view of the colorimeter.

FIG. 8 is a schematic sectional view of a transport block of the color measuring device according to the first embodiment.

FIG. 9 is a schematic perspective view of a lever of the colorimetric device according to the first embodiment.

FIG. 10 is a block diagram of a control unit that controls the operation of the colorimetric device according to the first embodiment.

FIG. 11 is a flowchart illustrating a calibration control routine according to the first and second embodiments.

FIG. 12 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. 13 is a schematic top view of the color measurement device schematically showing a state of the color measurement device when detecting a second reference line.

FIG. 14 shows a schematic configuration of a colorimetric device according to a second embodiment, in which (A) is a schematic sectional view of the colorimetric device;
(B) is a schematic side view of the color measuring device.

FIG. 15 is a block diagram of a control unit that controls the operation of the colorimetric device according to the second embodiment.

FIG. 16 is a schematic configuration diagram of a colorimeter of a colorimeter according to another embodiment.

17A and 17B show a schematic configuration of a conventional colorimeter, and FIG. 17A is a schematic perspective view and FIG. 17B 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 (colorimetric object) 122 Measurement surface 124 Cover 132 Compression coil spring (holding means) 144 Colorimeter (measuring device) 150 Means) 152 Base plate 156 Lever (moving means) 168 Motor 170 Torque limiter 186 Compression coil spring (holding means) 188 Eccentric cam (moving means) BS Measurement reference plane

Claims (3)

[Claims] 1. While scanning a surface to be measured of an object to be measured,
A colorimeter for measuring density or color, a measuring device attached with a light receiving surface for measuring a light amount according to density or color facing the measurement object, and the measurement device and the measurement object. Moving in a direction approaching each other, and a moving means for bringing the measurement target surface and the measurement object into contact with the measurement reference surface that always maintains a predetermined distance from the light receiving surface of the measurement device; and the measurement reference surface and the measurement object. Holding means for keeping the contact pressure with the object constant, and transport means for transporting the measuring instrument on the measurement object while bringing the measurement reference surface into contact with the measurement object by the movement means. A colorimetric device characterized by that: 2. The measuring device according to claim 1, wherein the moving means has a structure for moving the measuring instrument, and the holding means supports the measuring instrument via an urging force. Color device. 3. The apparatus according to claim 1, wherein the moving means has a structure for moving the object to be measured, and the holding means supports the object to be measured via an urging force. Colorimeter.