JP2002268314A - Method and instrument for measuring toner image density - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a measuring instrument, which correct errors in toner image density measurement, which are caused by leaked light from an optical path intercepting member of the instrument for measuring the toner image density. SOLUTION: The method for measuring the toner image density, which uses a light casting and receiving unit, provided with the optical path intercepting member for measuring the density of a toner image for density measurement, has a first measurement stage, a second measurement stage, a third measurement stage, a fourth measurement stage, a fifth measurement stage, a first operation stage, where a measured value corresponding to black toner obtained in the second measurement stage is normalized, on the basis of a measured value obtained in the first measurement stage, and a second operation stage where a measured value corresponding to each color toner obtained in the fourth measurement stage is corrected, on the basis of a measured value obtained in the third stage and the corrected measured value, corresponding to each color toner, is normalized on the basis of a measured value obtained in the fifth measurement stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a toner image density of a plurality of colors used for a color image forming apparatus and the like, and a toner image density measuring apparatus used for the method.

[0002]

2. Description of the Related Art At present, printers as image output terminals are rapidly spreading due to the development of computer network technology. In recent years, with the progress of color output, the stability of image quality of color printers and copiers has been increasing. There is a growing demand for improvements and uniform color image quality between color printers and copiers. In particular, regarding color reproducibility,
There is a demand for a high degree of stability that does not depend on changes in the installation environment, aging, or machine differences.

However, an electrophotographic image forming apparatus is
Since the image reproducibility fluctuates due to a change in environmental conditions where the apparatus is placed, the deterioration of the photoconductor and the developer over time, a high required value cannot be satisfied with the initial setting. Therefore, feedback control is performed to measure the density of the toner image during the image forming process or the like and reflect the result in the formation of the toner image to keep the color image density optimal.

In measuring the toner image density, specular reflection light that completely absorbs light is used for black toner, and diffuse reflection light is used for each color toner except black toner due to the difference in toner properties. An apparatus configured to receive light and diffuse reflected light with one sensor is generally used.

However, the sensitivity of sensors and light-emitting elements fluctuates due to environmental conditions such as temperature, aging of the elements themselves, and contamination due to toner adhesion. A solution has been proposed.

For example, Japanese Patent Application Laid-Open No. Hei 5-322760 discloses that a movable reference plate is rotatably provided between an object to be measured and a density detection sensor, and is used for correcting the sensor. A technique used to prevent a density detection sensor and a reference patch from being stained with toner is disclosed. Further, Japanese Patent Application Laid-Open No. 7-225501 discloses a technique in which a concentration detection sensor is stored in a storage container with a cover when detection is not performed, and a measured value is calibrated using a component member in the storage container. .

However, in the disclosed technique, since the reference plate and the density detection sensor are configured to be displaced, there is a problem that the positional relationship between the density detection sensor and the reference patch fluctuates and the measured value varies.

Accordingly, a toner image density measuring device in which a density detecting sensor and a reference plate are fixed has been developed.

FIGS. 1 and 2 show an example of a toner image density measuring apparatus having a light receiving element, two light emitting elements, a reference reflector and an optical path blocking member.

FIG. 1 is a view in which, in order to measure the density of a toner image, an optical path blocking member cuts off an optical path on which reflected light from a reference reflector is incident, and opens an optical path on which reflected light is incident at a measurement point. .

In FIG. 1, a toner image density measuring device 10
Is a light receiving element 11 and a measuring point 12
The light emitting element for specular reflection light 13 fixedly arranged at the position where the specular reflection light is incident on the light source and the light emitting element 14 for diffuse reflection light fixedly arranged at the position where the diffuse reflection light at the measurement point 12 is incident
A reference reflection plate 15 that reflects a part of the light from the light emitting element 14 for diffuse reflection light fixedly arranged at a position where the diffuse reflection light is incident; An optical path blocking member 18 for switching from the first light receiving path 16 where the light or the diffuse reflected light at the measurement point enters the light receiving element 11 to the second light receiving path 17 where the reflected light from the reference reflector enters the light receiving element 11; In order to measure the toner image density, the optical path blocking member 18 is provided on the first light receiving path 17 side such that specularly reflected light at the measurement point 12 or diffusely reflected light at the measurement point 12 is incident on the light receiving element 11. Has been switched to.

In this state, the regular reflection light emitting element 13 is turned on, the density of the transfer body on which the density measurement toner image is transferred and the density of the black toner image are measured, and the regular reflection light emitting element 13 is turned off. Then, the diffuse reflection light emitting element 14 is turned on to measure the toner image density of each color.

The density of the transfer member and the density of the black toner image can be measured with both the regular reflection light emitting element 13 and the diffuse reflection light emitting element 14 turned on.

FIG. 2 is a diagram when the optical path where the reflected light at the measuring point enters the light receiving element is blocked by an optical path blocking member, and the optical path where the reflected light from the reference reflector enters the light receiving element is opened. is there.

As compared with FIG. 1, the optical path blocking member 18 is slid toward the regular reflection light emitting element 13 side, and the regular reflection light at the measurement point 12 or the diffuse reflection light at the measurement point 12 enters the light receiving element 11. The first optical path 16 is blocked, and the second optical path 17 where the light reflected by the reference reflector 15 enters the light receiving element 11 is open.

With the light emitting element for specular reflection 13 turned off and the light emitting element for diffuse reflection light 14 turned on, the density of the reference reflector 17 is measured.

Since the sensitivity of the light emitting element and the light receiving element fluctuates due to environmental changes, aging degradation, toner adhesion, etc., it is necessary to cancel the relative reflectance by obtaining the relative reflectance with respect to the reference reflector.

However, since the surface of the transfer member onto which the toner image is transferred is smooth and the light irradiated on the surface is almost specularly reflected, the use of the transfer member as the reference reflector is effective for black toner. However, it is not suitable for a color toner.

Therefore, a reference reflector is separately provided, and the relative reflectance of the color toner is calculated based on the reflected light of the reference reflector.

According to this method, since the light-emitting element, the light-receiving element, and the reference reflector are all fixedly arranged, the dispersion of the measured values can be reduced, and the color toner can be relatively reflected using the reference reflector. Since the ratio is obtained, there is an advantage that the measurement accuracy can be improved.

[0021]

However, in the measuring method using the concentration measuring device shown in FIGS. 1 and 2, the optical path blocking member is slid toward the light emitting element for specular reflection light.
Slide to the light emitting element side for diffuse reflection light, and switch the optical path incident on the light receiving element between the optical path where the reflected light at the measurement point is incident and the optical path where the reflected light at the reference reflector is incident, and perform the density measurement. Is the way.

Since the concentration measuring device having such a mechanism has assembly tolerance and design tolerance at the time of manufacturing, it is difficult to completely block light that is irregularly reflected even if the optical path is switched.

Therefore, there is a problem that light leaks into the light receiving element from the gap of the blocked light path blocking member, and this light leak causes a measurement error in the density measurement.

In view of the above circumstances, the present invention provides a method for correcting an error in toner image density measurement caused by light leakage from an optical path blocking member of a toner image density measurement device, and a highly accurate toner image density measurement using the correction method. It is intended to provide a device.

[0025]

A first aspect of the present invention for achieving the above object is as follows.
The method for measuring the toner image density according to the invention comprises a first light-receiving element for receiving reflected light from a predetermined measurement point, and a first light-receiving element arranged at a position and a posture at which the regular reflection light at the measurement point enters the light-receiving element. A light-emitting element, a second light-emitting element disposed at a position and a position where the diffuse reflection light at the measurement point is incident on the light-receiving element, and a part of light emitted from the second light-emitting element is reflected. A reference reflector to be incident on the light receiving element,
One of a first optical path where the reflected light at the measurement point enters the light receiving element and a second optical path where the reflected light from the reference reflector enters the light receiving element, and the other Using a light emitting and receiving unit having an optical path blocking member for switching an optical path so as to open freely, a plurality of density measurement toner images of a plurality of color toners including black toner are carried on the surface in an arrayed state. The density of the density measurement toner image conveyed to the measurement point is measured by a toner image carrier that moves along the path passing through the measurement point and sequentially conveys the plurality of density measurement toner images to the measurement point. A first optical path switching state in which the first optical path is opened by the optical path blocking member to block the second optical path, the first light emitting element is turned on, and the second light emitting element is turned on. Glow The light incident on the light receiving element at a timing when any of the density measurement toner images is at a position different from the measurement point on the surface of the toner image carrier, which is executed in the first lighting switching state in which the child is turned off. At a timing when the density measurement toner image by the black toner is located at the measurement point, which is executed in the first measurement step of measuring the first optical path switching state and the first lighting switching state. A second measurement process of measuring light incident on the light receiving element, the first light path switching state, and a second lighting switching state in which the first light emitting element is turned off and the second light emitting element is turned on A third measuring step of measuring light incident on the light receiving element at a timing when the toner image for density measurement by the black toner is located at the measurement point, and the first optical path cutting And measuring the light incident on the light receiving element at each timing when the toner image for density measurement by each color toner except the black toner is located at the measurement point, which is executed in the second lighting switching state. And the second light path switching state in which the first light path is blocked by the light path blocking member to open the second light path, and the first light emitting element and the second light emitting element It is executed in a third lighting switching state in which at least the second light emitting element is turned on,
A fifth measurement step of measuring light incident on the light receiving element, and a measurement value corresponding to the black toner obtained in the second measurement step being measured values obtained in the first measurement step. The first calculation process of normalizing based on the above, and each measurement value corresponding to each color toner obtained in the fourth measurement process,
A second correction unit that corrects based on the measurement values obtained in the third measurement process and normalizes each corrected measurement value corresponding to each color toner based on the measurement values obtained in the fifth measurement process; And an operation step.

According to a second aspect of the invention, there is provided a method for measuring the density of a toner image, comprising: a light receiving element for receiving light reflected from a predetermined measuring point; and regular reflection light at the measuring point incident on the light receiving element. A first light emitting element disposed at a position and a posture, a second light emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point is incident on the light receiving element, and the second light emitting element A reference reflector for reflecting a part of the light emitted from the light source and entering the light receiving element; a first optical path on which the reflected light at the measurement point enters the light receiving element; and a reflected light from the reference reflector And a second light path incident on the light-receiving element, the light-transmitting / receiving unit having a light-blocking member for switching the light path so as to be able to switch so as to block one of the light paths and open the other. Including multiple color toners The measurement points are carried out by a toner image carrier that carries the density measurement toner images on the surface in an arrayed state, moves along a path passing through the measurement points, and sequentially conveys the plurality of density measurement toner images to the measurement points. A toner image density measuring method for measuring the density of a toner image for density measurement conveyed to a first optical path switching state in which the first optical path is opened by the optical path blocking member and the second optical path is blocked. Any density measurement toner image, which is executed in a fourth lighting switching state in which both the first light emitting element and the second light emitting element are turned on, is formed on the surface of the toner image carrier. A sixth measuring step of measuring light incident on the light receiving element at a timing different from the measurement point, and the black light-emitting mode executed in the first optical path switching state and the fourth lighting switching state. A seventh measuring step of measuring light incident on the light receiving element at a timing when the toner image for density measurement by the toner is located at the measurement point, the first optical path switching state, and the first light emitting element is turned off The light incident on the light receiving element is measured at a timing when the density measurement toner image of the black toner is located at the measurement point, which is executed in the second lighting switching state in which the second light emitting element is turned on. A third measurement process and respective timings at which the density measurement toner images of the respective color toners excluding the black toner are located at the measurement points, which are executed in the first optical path switching state and the second lighting switching state. A fourth measuring step of measuring light incident on the light receiving element, and a second optical path switching in which the first optical path is interrupted by the optical path interrupting member to open the second optical path. Light incident on the light receiving element, which is executed in a third lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. A fifth measuring step of measuring, wherein the measured value obtained in the sixth measuring step and the measured value corresponding to the black toner obtained in the seventh measuring step are converted into the third measuring step. And 3. normalizing the measured value corresponding to the black toner based on the corrected measured value obtained in the sixth measuring step, based on the measured value obtained in the above. The calculation process and the respective measurement values corresponding to each color toner obtained in the fourth measurement process are corrected based on the measurement values obtained in the third measurement process, and the corrected values corresponding to the respective color toners are corrected. In the fifth measurement process above, And having a second operation process of normalizing on the basis of obtained measurement values.

According to a third aspect of the invention, there is provided a toner image density measuring method for receiving light reflected from a predetermined measuring point, and specularly reflected light at the measuring point incident on the light receiving element. A first light emitting element disposed at a position and a posture, a second light emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point is incident on the light receiving element, and the second light emitting element A reference reflector for reflecting a part of the light emitted from the light source and entering the light receiving element; a first optical path on which the reflected light at the measurement point enters the light receiving element; and a reflected light from the reference reflector An optical path blocking member that switches an optical path so as to be able to switch so as to block one of the second optical path incident on the light receiving element and open the other, and the optical path blocking member connects the first optical path. Open and cut off the second optical path A plurality of density measurement toner images of a plurality of color toners including a black toner are carried on the surface in an arranged state by using a light emitting / receiving unit having a shutter for opening and closing the first optical path. The density of the toner image for density measurement conveyed to the measurement point is measured by a toner image carrier that moves along the path passing through the measurement point and sequentially conveys the plurality of toner images for density measurement to the measurement point. A third optical path switching state in which the first optical path is opened by the optical path blocking member to block the second optical path, and the shutter is retracted from the first optical path; Any of the density measurement toner images, which is executed in the first lighting switching state in which the first light emitting element is turned on and the second light emitting element is turned off, is on the surface of the toner image carrier. And the eighth measurement process of measuring the incident light to the light receiving element at the timing which is in a different position from the fixed point, the third optical path switching state, and is executed in the first lighting switching state,
A ninth measurement process of measuring light incident on the light receiving element at a timing when the density measurement toner image by the black toner is positioned at the measurement point, and a third optical path switching state;
And executed in a second lighting switching state in which the first light emitting element is turned off and the second light emitting element is turned on.
A tenth measuring step of measuring light incident on the light receiving element at each timing when a toner image for density measurement by each color toner except the black toner is located at the measurement point; To open the second optical path to block the second optical path and close the shutter, and that at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. Third
An eleventh measurement step of measuring the incident light on the light receiving element, which is executed in the lighting switching state of (a), and a fifth step in which the optical path blocking member blocks the first optical path and opens the second optical path. A twelfth measurement step of measuring light incident on the light receiving element, which is performed in the optical path switching state and the third lighting switching state, and the black toner obtained in the ninth measurement step. A fourth calculation step of normalizing the measured value corresponding to the above based on the measured value obtained in the eighth measuring step, and each measured value corresponding to each color toner obtained in the tenth measuring step, Fifth, the correction is performed based on the measurement values obtained in the eleventh measurement process, and the corrected measurement values corresponding to the respective color toners are normalized based on the measurement values obtained in the twelfth measurement process. And an operation process of That.

According to a fourth aspect of the invention, there is provided a toner image density measuring method for receiving a reflected light from a predetermined measuring point, and a specularly reflected light at the measuring point incident on the light receiving element. A first light emitting element disposed at a position and a posture, a second light emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point is incident on the light receiving element, and the second light emitting element A reference reflector for reflecting a part of the light emitted from the light source and entering the light receiving element; a first optical path on which the reflected light at the measurement point enters the light receiving element; and a reflected light from the reference reflector An optical path blocking member that switches an optical path so as to be able to switch so as to block one of the second optical path incident on the light receiving element and open the other, and the optical path blocking member connects the first optical path. Open and cut off the second optical path A plurality of density measurement toner images of a plurality of color toners including a black toner are carried on the surface in an arranged state by using a light emitting / receiving unit having a shutter for opening and closing the first optical path. The density of the toner image for density measurement conveyed to the measurement point is measured by a toner image carrier that moves along the path passing through the measurement point and sequentially conveys the plurality of toner images for density measurement to the measurement point. A third optical path switching state in which the first optical path is opened by the optical path blocking member to block the second optical path, and the shutter is retracted from the first optical path; Any of the density measurement toner images executed in the fourth lighting switching state in which both the first light emitting element and the second light emitting element are turned on is formed on the surface of the toner image carrier. A thirteenth measurement process of measuring the incident light to the light receiving element at the timing which is in a different position from the fixed point, the third optical path switching state, and is executed in the fourth lighting switching state of
A fourteenth measuring step of measuring light incident on the light receiving element at a timing when the toner image for density measurement by the black toner is located at the measurement point, the third optical path switching state, and the first light emitting element Is turned off and the second light-emitting element is turned on, and the light-receiving element is turned on at each timing when a toner image for density measurement of each color toner except the black toner is located at the measurement point. A tenth measurement step of measuring light incident on the
The optical path blocking member opens the first optical path and opens the second optical path.
In a fourth light path switching state in which the light path is blocked and the shutter is closed, and in a third lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. An eleventh measuring step of measuring incident light to the light receiving element, a fifth optical path switching state in which the optical path blocking member blocks the first optical path and opens the second optical path, And a twelfth measurement step of measuring light incident on the light receiving element, which is performed in the third lighting switching state.
The measurement value obtained in the measurement process and the measurement value corresponding to the black toner obtained in the fourteenth measurement process are corrected based on the measurement value obtained in the eleventh measurement process, and the black toner is corrected. A sixth calculating step of normalizing the corrected measured value corresponding to the above based on the corrected measured value obtained in the thirteenth measuring step, and a process for each color toner obtained in the tenth measuring step. Each corresponding measurement value is corrected based on the measurement value obtained in the eleventh measurement process, and each corrected measurement value corresponding to each color toner is converted to the measurement value obtained in the twelfth measurement process. And a fifth operation step of normalizing based on the information.

According to a fifth aspect of the present invention, there is provided a toner image density measuring apparatus for receiving light reflected from a predetermined measuring point, and specularly reflected light at the measuring point incident on the light receiving element. A first light emitting element disposed at a position and a posture, a second light emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point is incident on the light receiving element, and the second light emitting element A reference reflector for reflecting a part of the light emitted from the light source and entering the light receiving element; a first optical path on which the reflected light at the measurement point enters the light receiving element; and a reflected light from the reference reflector And a second light path incident on the light-receiving element, the light-transmitting / receiving unit having a light-blocking member for switching the light path so as to be able to switch so as to block one of the light paths and open the other. Including multiple color toners The measurement points are carried out by a toner image carrier that carries the density measurement toner images on the surface in an arrayed state, moves along a path passing through the measurement points, and sequentially conveys the plurality of density measurement toner images to the measurement points. A first optical path switching state in which the first optical path is opened by the optical path blocking member and the second optical path is blocked, in the toner image density measuring device for measuring the density of the toner image for density measurement conveyed to In addition, in the first lighting switching state in which the first light emitting element is turned on and the second light emitting element is turned off, any of the density measurement toner images is measured at the measurement point on the surface of the toner image carrier. A first measuring means for measuring light incident on the light receiving element at a timing different from the position of the light receiving element; and a black light trigger executed in the first light path switching state and the first lighting switching state. A second measuring means for measuring light incident on the light receiving element at a timing when the toner image for density measurement is located at the measurement point; a first light path switching state; and the first light emitting element is turned off. The light incident on the light receiving element is measured at a timing when the density measurement toner image of the black toner is located at the measurement point, which is executed in the second lighting switching state in which the second light emitting element is turned on. A third measuring means, and respective timings at which the density measurement toner images of the respective color toners except the black toner are located at the measurement points, which are executed in the first light path switching state and the second lighting switching state. A fourth measuring means for measuring light incident on the light receiving element, and a second optical path switching state in which the first optical path is interrupted by the optical path interrupting member to open the second optical path. And light incident on the light receiving element, which is executed in a third lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. A fifth measuring unit for measuring, and normalizing the measured value corresponding to the black toner obtained by the second measuring unit based on the measured value obtained by the first measuring unit. The arithmetic unit and the respective measurement values corresponding to the respective color toners obtained by the fourth measurement unit are corrected based on the measurement values obtained by the third measurement unit, and the corrected values corresponding to the respective color toners are corrected. A second calculating means for normalizing each measured value based on the measured value obtained by the fifth measuring means.

According to a sixth aspect of the present invention, there is provided a toner image density measuring apparatus for receiving light reflected from a predetermined measuring point, and specularly reflected light at the measuring point incident on the light receiving element. A first light emitting element disposed at a position and a posture, a second light emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point is incident on the light receiving element, and the second light emitting element A reference reflector for reflecting a part of the light emitted from the light source and entering the light receiving element; a first optical path on which the reflected light at the measurement point enters the light receiving element; and a reflected light from the reference reflector And a second light path incident on the light-receiving element, the light-transmitting / receiving unit having a light-blocking member for switching the light path so as to be able to switch so as to block one of the light paths and open the other. Including multiple color toners The measurement points are carried out by a toner image carrier that carries the density measurement toner images on the surface in an arrayed state, moves along a path passing through the measurement points, and sequentially conveys the plurality of density measurement toner images to the measurement points. A first optical path switching state in which the first optical path is opened by the optical path blocking member and the second optical path is blocked, in the toner image density measuring device for measuring the density of the toner image for density measurement conveyed to Any density measurement toner image, which is executed in a fourth lighting switching state in which both the first light emitting element and the second light emitting element are turned on, is formed on the surface of the toner image carrier. Sixth measuring means for measuring the light incident on the light receiving element at a timing different from the measurement point, and the black light measuring means, which is executed in the first light path switching state and the fourth lighting switching state. A seventh measuring means for measuring light incident on the light receiving element at a timing when the toner image for density measurement by the toner is located at the measurement point, the first optical path switching state, and the first light emitting element is turned off The light incident on the light receiving element is measured at a timing when the density measurement toner image of the black toner is located at the measurement point, which is executed in the second lighting switching state in which the second light emitting element is turned on. A third measuring means, and respective timings at which the density measurement toner images of the respective color toners except the black toner are located at the measurement points, which are executed in the first light path switching state and the second lighting switching state. A fourth measuring means for measuring light incident on the light receiving element, and a second optical path switching in which the first optical path is interrupted by the optical path interrupting member to open the second optical path. Light incident on the light receiving element, which is executed in a third lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. A fifth measuring means for measuring, and a third measuring means for measuring the measured value obtained by the sixth measuring means and the measured value corresponding to the black toner obtained by the seventh measuring means. A third calculating means for correcting based on the measured value obtained in the above and normalizing the corrected measured value corresponding to the black toner based on the corrected measured value obtained by the sixth measuring means. And correcting each measurement value corresponding to each color toner obtained by the fourth measurement unit with each color toner corrected based on the measurement value obtained by the third measurement unit, and performing each measurement. The value was measured by the fifth measuring means. And having a second calculating means for normalizing, based on the value.

According to a seventh aspect of the present invention, there is provided a toner image density measuring apparatus for receiving light reflected from a predetermined measuring point, and specularly reflected light at the measuring point incident on the light receiving element. A first light emitting element disposed at a position and a posture, a second light emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point is incident on the light receiving element, and the second light emitting element A reference reflector for reflecting a part of the light emitted from the light source and entering the light receiving element; a first optical path on which the reflected light at the measurement point enters the light receiving element; and a reflected light from the reference reflector An optical path blocking member that switches an optical path so as to be able to switch so as to block one of the second optical path incident on the light receiving element and open the other, and the optical path blocking member connects the first optical path. Open and cut off the second optical path A plurality of density measurement toner images of a plurality of color toners including a black toner are carried on the surface in an arranged state by using a light emitting / receiving unit having a shutter for opening and closing the first optical path. The density of the toner image for density measurement conveyed to the measurement point is measured by a toner image carrier that moves along the path passing through the measurement point and sequentially conveys the plurality of toner images for density measurement to the measurement point. A third optical path switching state in which the first optical path is opened by the optical path blocking member to block the second optical path and the shutter is retracted from the first optical path; Any of the density measurement toner images, which is executed in the first lighting switching state in which the first light emitting element is turned on and the second light emitting element is turned off, is on the surface of the toner image carrier. And eighth measuring means for measuring the incident light to the light receiving element at the timing which is in a different position from the fixed point, the third optical path switching state, and is executed in the first lighting switching state,
Ninth measuring means for measuring light incident on the light receiving element at the timing when the density measurement toner image by the black toner is located at the measurement point; and the third optical path switching state;
And executed in a second lighting switching state in which the first light emitting element is turned off and the second light emitting element is turned on.
A tenth measuring means for measuring light incident on the light receiving element at each timing when a toner image for density measurement by each color toner except the black toner is located at the measurement point; and wherein the optical path blocking member is the first optical path. To open the second optical path to block the second optical path and close the shutter, and that at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. Third
An eleventh measuring means for measuring the incident light to the light receiving element, which is executed in the lighting switching state, and a fifth optical element in which the optical path blocking member blocks the first optical path and opens the second optical path. And a twelfth measuring means for measuring light incident on the light receiving element, which is executed in the light path switching state and the third lighting switching state, and the black toner obtained by the ninth measuring means. A fourth calculating means for normalizing the measured value corresponding to the above based on the measured value obtained by the eighth measuring means, and each measured value corresponding to each color toner obtained by the tenth measuring means, Fifth, a correction corresponding to each color toner corrected based on the measurement value obtained by the eleventh measurement unit and a normalization of each measurement value based on the measurement value obtained by the twelfth measurement unit. And arithmetic means of That.

According to an eighth aspect of the present invention, there is provided a toner image density measuring apparatus for receiving reflected light from a predetermined measuring point, and specularly reflected light at the measuring point incident on the light receiving element. A first light emitting element disposed at a position and a posture, a second light emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point is incident on the light receiving element, and the second light emitting element A reference reflector for reflecting a part of the light emitted from the light source and entering the light receiving element; a first optical path on which the reflected light at the measurement point enters the light receiving element; and a reflected light from the reference reflector An optical path blocking member that switches an optical path so as to be able to switch so as to block one of the second optical path incident on the light receiving element and open the other, and the optical path blocking member connects the first optical path. Open and cut off the second optical path A plurality of density measurement toner images of a plurality of color toners including a black toner are carried on the surface in an arranged state by using a light emitting / receiving unit having a shutter for opening and closing the first optical path. The density of the toner image for density measurement conveyed to the measurement point is measured by a toner image carrier that moves along the path passing through the measurement point and sequentially conveys the plurality of toner images for density measurement to the measurement point. A third optical path switching state in which the first optical path is opened by the optical path blocking member to block the second optical path and the shutter is retracted from the first optical path; Any of the density measurement toner images executed in the fourth lighting switching state in which both the first light emitting element and the second light emitting element are turned on is formed on the surface of the toner image carrier. A thirteenth measuring means for measuring the incident light to the light receiving element at the timing which is in a different position from the fixed point, the third optical path switching state, and is executed in the fourth lighting switching state of
A fourteenth measuring means for measuring light incident on the light receiving element at a timing when the toner image for density measurement by the black toner is located at the measurement point; a third light path switching state; and the first light emitting element Is turned off and the second light-emitting element is turned on, and the light-receiving element is turned on at each timing when a toner image for density measurement of each color toner except the black toner is located at the measurement point. Tenth measuring means for measuring light incident on the
The optical path blocking member opens the first optical path and opens the second optical path.
In a third light path switching state in which the light path is blocked and the shutter is closed, and in a fourth lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. An eleventh measuring means for measuring incident light to the light receiving element, and a fifth optical path switching state in which the optical path blocking member blocks the first optical path and opens the second optical path, And a twelfth measuring means for measuring light incident on the light receiving element, which is executed in the third lighting switching state.
The measurement value obtained by the measurement means and the measurement value corresponding to the black toner obtained by the fourteenth measurement means are corrected based on the measurement value obtained by the eleventh measurement means, and the black toner is corrected. A sixth calculating means for normalizing the corrected measured value corresponding to the above based on the corrected measured value obtained by the thirteenth measuring means, and a color calculating means for each color toner obtained by the tenth measuring means. The corresponding measured values are corrected based on the measured values obtained by the eleventh measuring means, and the corrected measured values corresponding to the respective color toners are converted to the measured values obtained by the twelfth measuring means. And a fifth calculating means for normalizing based on the information.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the toner image density measuring method according to the first invention will be described.

First, a process for forming a plurality of toner images for density measurement for density measurement will be described.

FIG. 3 is a diagram showing an example of the configuration of an image forming apparatus for forming a plurality of toner images for density measurement according to the first embodiment of the present invention.

In the image forming apparatus shown in FIG. 3, four image carriers 21 on each of which a toner image is formed by each color material are arranged in series with their rotation axes parallel. The charger 22 uniformly charges the surface of each image carrier 21 to a predetermined potential, and the control unit 23 transmits an image signal of a predetermined pattern for forming a toner image for density measurement to the exposure device 24. Output to
The exposure device 24 irradiates the uniformly charged surface of the image carrier 21 with exposure light to form an electrostatic latent image.
The electrostatic latent image is developed with each color toner to form a toner image for density measurement of each color. The transfer device 26 at a position facing each image carrier carries the developed toner image for density measurement of each color on the paper transport belt 2 wrapped around a roll 28.
7, and the transferred toner images for density measurement are
Measurement point 2 is caused by circulating movement of paper transport belt 27.
9. The toner image density measuring device 30 is provided on the measuring point 29 downstream of the four image carriers arranged in the circulating movement direction A of the paper transport belt 27,
The density of each color toner image conveyed to 9 is measured.

Here, the toner image density measuring device 30 has the same configuration as that shown as a conventional example in FIGS. 1 and 2, and a detailed description thereof will be omitted.

Each developing device 25 is provided with black, cyan, magenta and yellow toners from the downstream side in the circulating movement direction A of the paper transport belt 27, and is provided on the paper transport belt in the circulating movement direction. Density measurement toner images of black, cyan, magenta, and yellow are arranged from the downstream side of A. After the transfer of the toner image, the toner still remaining on the image carrier is removed by a cleaner (not shown), and the toner image for density measurement is formed on the paper transport belt 27 and the density measurement is completed. Are erased by a cleaning device (not shown).

The process of forming the toner image for density measurement is not limited to the process described in the present embodiment, but may be any process.

FIG. 4 is a sequence chart showing a toner image density measuring method according to the first embodiment of the present invention.

The upper part of the sequence shown in FIG. 4 is a density measuring toner image (hereinafter, referred to as "black toner") of black toner which is sequentially conveyed to the toner image density measuring point where the toner image density measuring device is disposed. Image) and a toner image for density measurement using color toner (hereinafter, referred to as “color toner image”). In the middle (upper and lower), specularly reflected light at the measurement point enters the light receiving element. Timing of turning on and off the first light emitting element arranged at the position and posture to be turned on, and turning on and off the second light emitting element arranged at the position and posture at which the diffuse reflection light at the measurement point enters the light receiving element The lower part shows the timing at which the optical path blocking member slides and switches from the first optical path to the second optical path.

The upper black toner image and color toner image are
It is composed of a plurality of patches having different image densities, and the last patch of the plurality of patches is a solid patch having an image density of 100%.

The measurement is started in a first optical path switching state in which the first optical path is opened by the optical path blocking member and the second optical path is blocked.

At time t1, the light emitting element for regular reflection light L1 is turned on, and the density Vclean of the conveyor belt at the measurement point is measured.

The black toner image densities V k having different image densities are sequentially measured from time t2, and the solid patch density is measured from time t3 to time t4. At time t4, the light emitting element for regular reflection light is turned off. The light emitting element for the diffuse reflection light is turned on, and at time t5, the black toner image passes through the measurement point until the black toner image passes through the measurement point.
The light leakage Verr from the second optical path is measured.

Since the solid patch of black toner completely absorbs light, even if the light emitting element for diffuse reflection light is turned on, the reflected light hardly enters the light receiving element. Even though the light passes through the transfer belt, the light is substantially specularly reflected by the conveyor belt, so that the amount of light incident on the light receiving element is not usually a problem.

The density Vpc of each color toner image sequentially conveyed between time t6 and time t7 is measured.

After the density measurement of the color toner image has been completed and the toner image for density measurement has passed the measurement point, the first light path is blocked by the light path blocking member and the second light path is opened by opening the second light path. In this state, the reflected light Vref from the reference reflector is measured.

Next, based on the above-described measured values, a toner image density in which a measurement error due to light leakage is corrected is calculated.

The black toner image density is calculated by Vk / Vclean, and the color toner image density is calculated by (Vpc-Verr) / Vref.

In the present embodiment, since the density measurement of the black toner image is performed with the light emitting element for diffuse reflection light turned off, there is no need to correct the density of the black toner image. Since the reflection light emitting element is turned on, the color toner image density needs to be corrected.

Next, an embodiment of the toner image density measuring method according to the second invention will be described.

The second embodiment differs from the first embodiment in that the density of the black toner image is measured with both the regular reflection light emitting element and the diffuse reflection light emitting element turned on. Is different, but the other points are the same.
A description of a process for forming a toner image for density measurement and a description of a toner image density measuring device will be omitted.

FIG. 5 is a sequence chart showing a toner image density measuring method according to the second embodiment of the present invention.

The significance of the sequence shown in FIG. 5 is the same as the significance of the sequence described in FIG. 4, and a description thereof will be omitted.

The measurement is started in a first optical path switching state in which the first optical path is opened by the optical path blocking member and the second optical path is blocked.

At time t1, the density Vclean of the transport belt at the measurement point is measured with both the light emitting element for specular reflection light and the light emitting element for diffuse reflection light turned on.

From time t2, the density V k of the black toner images having different image densities is measured, and from time t3 to time t4, the density of the solid patch is measured. The leakage light Verr from the second optical path is measured until the time t5 when the image passes through the measurement point.

Since the black toner solid patch completely absorbs light, even if the light emitting element for diffuse reflection light is turned on,
It is considered that the reflected light hardly enters the light receiving element.

Although the light leakage is measured with the light emitting element for specular reflection light turned off, the black toner solid patch absorbs light from the light emitting element for specular reflection light. The measurement can also be performed in a state where both the light emitting element for diffuse reflection light and the light emitting element for diffuse reflection light are turned on.

While the light emitting element for specular reflection light is turned off and the light emitting element for diffuse reflection light is turned on, the density Vpc of the color toner image sequentially conveyed during the period from time t6 to time t7. Measured.

After the density measurement of the color toner image has been completed and the toner image for density measurement has passed the measurement point, the first optical path of the optical path blocking member is blocked to open the second optical path, and the second optical path switching is performed. In this state, the reflected light Vref from the reference reflector is measured.

Next, a toner image density in which a measurement error due to light leakage has been corrected is calculated based on the above measured values.

The density of the black toner image is (V k -V err) /
(Vclean−Verr) and the color toner image density is calculated by (Vpc−Verr) / Vref.

In the present embodiment, the measurement of the density of the conveyor belt and the measurement of the density of the black toner image are performed while the light emitting element for diffuse reflection light is turned on.

Next, an embodiment of the toner image density measuring method according to the third invention will be described.

FIG. 6 is a sequence chart showing a toner image density measuring method according to the third embodiment of the present invention.

The third embodiment differs from the first embodiment in that the toner image density measuring device moves the light path of the irradiation light from the light emitting element for diffuse reflection light to the measurement point for a predetermined time. Although the shutter for closing is provided closer to the measurement point than the reference reflector on the optical path of the irradiation light directed to the measurement point, the difference is that the shutter is closed and the light leakage from the second optical path is measured.
The other points are the same, and only the differences will be described.

The mounting position of the shutter and the like will be described later in an embodiment of a toner image density measuring apparatus according to a seventh aspect of the present invention, and a description thereof will be omitted.

The sequence of the present embodiment shown in FIG. 6 is different from the sequence of the first embodiment of the present invention described with reference to FIG. 4 in that the time from time t4 to time t5 before the black toner image passes the measurement point. In the meantime, the light emitting element for specular reflection light is turned off, the light emitting element for diffuse reflection light is turned on, and the optical path of the irradiation light from the light emitting element for diffuse reflection light toward the measurement point is closer to the measurement point than the reference reflector. Is different in that the shutter provided for the shutter is interrupted for a predetermined time.

Here, the interruption time by the shutter is not limited to time t4 to time t5, but can be set arbitrarily.

At time t1, the light emitting element for regular reflection light is turned on, and the density Vclean of the transport belt at the measurement point is measured.

The black toner image densities V k having different image densities are sequentially measured from time t2 to time t3.

The density of the solid patch is measured from time t3 to time t4, the light emitting element for specular reflection light is turned off and the light emitting element for diffuse reflection light is turned on at the same time, and the shutter is closed at that timing.

The light leakage Verr from the second optical path is measured until the time t5 when the shutter is closed.

Here, the light leakage Ver from the second optical path is referred to as Ver.
r is measured from time t4 to time t5, but need not necessarily be measured from time t4 to time t5, and may be measured from time t1 to time t2. Even after t5, it can be measured at any time.

The leaked light Verr is measured in a state where the light emitting element for specular reflection light is turned off and the light emitted from the light emitting element for diffuse reflection light to the measurement point is completely blocked. It can be accurately grasped without being affected by the density of light or transmitted light.

The method of calculating the density of the black toner image and the density of the color toner image is the same as that of the first embodiment, and therefore the description is omitted.

Next, an embodiment of the toner image density measuring method according to the fourth invention will be described.

FIG. 7 is a sequence chart showing a toner image density measuring method according to the fourth embodiment.

The sequence of the present embodiment shown in FIG. 7 is different from the sequence of the second embodiment of the present invention described with reference to FIG. 5 in that the time from time t4 to time t5 before the black toner image passes the measurement point. The difference is that the optical path of the irradiation light from the light emitting element for diffuse reflection light toward the measurement point is blocked for a predetermined time by a shutter provided closer to the measurement point than the reference reflector, but otherwise the same. The difference will be described.

Here, the shut-off time by the shutter is not limited to time t4 to time t5, but can be set arbitrarily.

At time t1, the light emitting element for specular reflection light and the light emitting element for diffuse reflection light are both turned on, and the density Vclean of the transport belt at the measurement point is measured.

The black toner image densities V k having different image densities are sequentially measured from time t2 to time t3.

The density of the solid patch is measured from time t3 to time t4, and the shutter is closed at the timing when the light emitting element for regular reflection light is turned off.
During this time, the light leakage Verr from the second optical path is measured.

The light leakage Verr from the second optical path does not necessarily need to be measured from time t4 to time t5, and may be measured from time t1 to time t2, or after time t5. Even if there is, it can be measured at any time.

The light leakage Verr is measured in a state where the light emitting element for specular reflection light is turned off and the light emitted from the light emitting element for diffuse reflection light to the measurement point is completely blocked.
It is possible to accurately grasp without being affected by the density of the black toner image, transmitted light, and the like.

The method of calculating the density of the black toner image and the density of the color toner image is the same as that of the second embodiment, so that the description is omitted.

Next, an embodiment of the toner image density measuring apparatus according to the fifth invention will be described.

FIGS. 8 and 9 show an embodiment of the toner image density measuring apparatus according to the fifth invention.

FIG. 8 shows that in order to measure the toner image density, the first optical path 46 on which the reflected light at the measuring point 42 is incident is opened, and the reflected light from the reference reflecting plate 45 is incident by the optical path blocking member 48. FIG. 4 is a schematic configuration diagram in a first optical path switching state in which a second optical path 47 is blocked.

In FIG. 8, the toner image density measuring device 40
Is a light receiving element 41 and a measuring point 42
The light-emitting element 43 for specular reflection light is fixedly arranged at the position where the specular reflection light is incident on the device, and the light-emitting element 44 for diffuse reflection light fixedly arranged at the position where the diffuse reflection light at the measurement point 42 is incident.
A reference reflection plate 45 that reflects a part of light from the diffuse reflection light emitting element 44 fixedly disposed at a position where the diffuse reflection light is incident; An optical path blocking member 48 for switching from a first light receiving path 46 in which light or diffusely reflected light at a measurement point enters the light receiving element 41 to a second light receiving path 47 in which reflected light from the reference reflector enters the light receiving element 41; , Measuring unit 3 for performing measurement according to the measurement procedure
7 and a measurement control unit 49 having a calculation unit 38 for performing calculations based on the obtained measurement values.

The measurement section of the measurement control section 49 performs switching of lighting of the light emitting element 43 for regular reflection light and light emitting element 44 for diffuse reflection light and switching of the light path of the light path blocking member 48 in accordance with a predetermined measurement procedure. A predetermined operation is performed based on the measurement value obtained by the light receiving element 41 receiving the light by the switching of the light and the switching of the optical path by the measuring unit 37 to normalize the black toner image density and the toner image density of each color.

Note that the contents of the measurement and the contents of the calculation are the same as those of the first embodiment of the present invention, and a description thereof will be omitted.

Here, in order to measure the toner image density,
The light path blocking member 48 is in a first light path switching state in which the light path switching member 48 switches to the first light receiving path 46 side such that specular reflection light at the measurement point 42 or diffuse reflection light at the measurement point 42 enters the light receiving element 41. I have.

In this state, the light emitting element 43 for regular reflection light is turned on to measure the density of the transfer body on which the toner image for density measurement is transferred and the density of the black toner image.
3 is turned off, the diffuse reflection light emitting element 44 is turned on, and the toner image density of each color is measured.

The density of the transfer member and the density of the black toner image can be measured with both the regular reflection light emitting element 43 and the diffuse reflection light emitting element 44 turned on.

Next, an embodiment of the toner image density measuring apparatus according to the sixth invention will be described.

The embodiment of the toner image density measuring device according to the sixth invention is different from the embodiment of the toner image density measuring device according to the fifth invention in that the measurement contents and the calculation unit performed by the measuring unit 37 of the measurement control unit 49 are different. Although the contents of calculation performed by 38 are different, the other components are the same, and the measurement contents and calculation contents of the measurement control unit 49 are the same as those of the second embodiment of the present invention, so that the description is omitted.

Next, an embodiment of a toner image density measuring apparatus according to the seventh invention will be described.

The seventh embodiment is different from the fifth embodiment in that a shutter is provided, and leakage light from the light path blocking member in the first light path switching state is measured by closing the shutter. The difference is the same except for the above, and the difference will be described.

FIG. 10 is a diagram showing a state in which the shutter is closed in the first optical path switching state in the toner image density measuring apparatus according to the seventh embodiment of the present invention.

As compared with the toner image density measuring devices shown in FIGS. 8 and 9 for explaining the fifth embodiment of the present invention, the shutter 49 is provided and the operation of the measurement control unit 59 is different.

Therefore, the same components as those in FIGS. 8 and 9 are denoted by the same reference numerals, and differences will be described.

The toner image density measuring device 50 shown in FIG.
The light-emitting element 44 for diffuse reflection light is turned on, and the optical path blocking member 48 opens the first optical path 46 where the regular reflection light at the measurement point 42 or the diffuse reflection light at the measurement point 42 enters the light receiving element 41. The first optical path switching state is set.

A sliding shutter 49 is disposed in front of the light-emitting element window 51 for specular reflection light and the light-emitting element window 52 for diffuse reflection light in the optical system housing of the toner image density measuring device 50, and the shutter 49 is closed. And the first optical path 46 where the light reflected at the measurement point 42 enters the light receiving element 41 is completely blocked for a predetermined time.

With this configuration, it is possible to accurately grasp the leakage light received by the light receiving element 41 when the first optical path 46 is opened and the second optical path 47 is blocked.

The measurement contents of the measurement section 57 of the measurement control section 59 and the calculation contents of the calculation section 58 are the same as those of the third embodiment, and the description is omitted.

Incidentally, if this shutter 49 is used, the first
The light reflected by the reference reflecting plate 45, which is measured in a state where the optical path 46 is blocked and the second optical path 47 is opened, can be accurately grasped.

Next, an embodiment of the toner image density measuring apparatus according to the eighth invention will be described.

The eighth embodiment differs from the seventh embodiment in that the measurement contents performed by the measurement unit 57 of the measurement control unit 59 and the calculation contents performed by the calculation unit 58 are different from each other, but are otherwise the same. In addition, since the measurement contents and calculation contents of the measurement control unit 59 are the same as those of the fourth embodiment, the description is omitted.

[0112]

As described above, when the toner image density measuring methods of the first and second aspects of the present invention are used, light leakage from the reflector can be detected by a simple method without using a special device. Since the measured image density is corrected, highly accurate toner image density measurement can be realized at low cost. Further, the toner image density measuring devices according to the fifth and sixth inventions can realize highly accurate toner image density measurement at low cost. Third,
The toner image density measuring method according to the fourth aspect of the present invention enables more accurate measurement of the toner image density by reliably detecting light leakage from the light path blocking member by the shutter. Since the measuring device includes the shutter, it is possible to measure the toner image density with higher accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a toner image density measuring device.

FIG. 2 is a diagram when an optical path where reflected light at a measurement point enters a light receiving element is blocked by an optical path blocking member, and an optical path where reflected light from a reference reflector enters the light receiving element is opened.

FIG. 3 is a diagram illustrating a configuration example of an image forming apparatus that forms a plurality of density measurement toner images according to the first embodiment of the present invention.

FIG. 4 is a sequence chart showing an embodiment of the toner image density measuring method according to the first invention.

FIG. 5 is a sequence chart showing an embodiment of a toner image density measuring method according to the second invention.

FIG. 6 is a sequence chart showing an embodiment of a toner image density measuring method according to the third invention.

FIG. 7 is a sequence chart showing an embodiment of a toner image density measuring method according to the fourth invention.

FIG. 8 is a diagram showing an embodiment of a toner image density measuring device according to the fifth invention.

FIG. 9 is a diagram showing an embodiment of a toner image density measuring device according to the fifth invention.

FIG. 10 is a diagram illustrating a state in which a shutter is closed in a first optical path switching state in the toner image density measuring device according to the seventh embodiment of the present invention.

[Explanation of symbols]

 10, 30, 40, 50 Toner image density measuring device 11, 41 Light receiving element 12, 29, 42 Measurement point 13, 43 Light emitting element for regular reflection light 14, 44 Light emitting element for diffuse reflection light 15, 45 Reference reflecting plate 16, 46 first optical path 17, 47 second optical path 18, 48 optical path blocking member 21 image carrier 22 charger 23 control unit 24 exposure device 25 developing device 26 transfer device 27 paper transport belt 28 roll 37, 57 measuring unit 38, 58 arithmetic unit 49, 59 measurement control unit 56 shutter

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G059 AA01 BB06 BB09 CC19 DD02 EE02 FF08 GG03 JJ13 JJ23 KK01 MM01 MM14 2H027 DA09 DE02 DE07 DE10 EA20 EB04 EC03 EC06 2H030 AB02 AD16 BB36 BB44 DA63 DA03 DA03 DA03

Claims (8)

[Claims] A light-receiving element for receiving reflected light from a predetermined measurement point; a first light-emitting element arranged at a position and a posture at which regular reflection light at the measurement point enters the light-receiving element; A second light emitting element disposed at a position and a position where the diffuse reflection light at the measurement point is incident on the light receiving element;
A reference reflector that reflects a part of the light emitted from the light emitting element and makes the light incident on the light receiving element, a first optical path where the reflected light at the measurement point enters the light receiving element, and the reference reflector. Using a light-projecting and receiving unit having a light-path blocking member that switches the light path so as to switch one of the second light path incident on the light-receiving element and the other to open the other. A plurality of density measurement toner images each of which includes a plurality of color toners including a black toner, are arranged on the surface, are moved on a path passing through the measurement point, and the plurality of density measurement toner images are sequentially measured. A toner image density measurement method for measuring the density of a density measurement toner image conveyed to the measurement point by a toner image conveyance body conveyed to a point, wherein the first optical path is opened by the optical path blocking member, and 2 The first optical path switching state in which the optical path of
The density measurement toner image is executed in a first lighting switching state in which the light emitting element is turned on and the second light emitting element is turned off, and any density measurement toner image is located at a position different from the measurement point on the surface of the toner image carrier. A first measuring step of measuring the light incident on the light receiving element at a certain timing; and a toner for density measurement using the black toner, which is executed in the first optical path switching state and the first lighting switching state. A second measuring step of measuring light incident on the light receiving element at a timing when an image is located at the measurement point; the first light path switching state, and the first light emitting element is turned off and the second light emission is performed. The light incident on the light receiving element is measured at a timing when the density measurement toner image of the black toner is located at the measurement point, which is executed in the second lighting switching state in which the element is turned on. A third measurement process, and timings at which the density measurement toner images of the respective color toners excluding the black toner are located at the measurement points, which are executed in the first optical path switching state and the second lighting switching state. In the fourth step, the incident light to the light receiving element is measured.
And a second light path switching state in which the first light path is blocked by the light path blocking member to open the second light path, and the first light emitting element and the second light emitting element A fifth measuring step of measuring light incident on the light receiving element, the fifth measuring step being performed in a third lighting switching state in which at least the second light emitting element is turned on, and the second measuring step A first calculation step of normalizing the measured value corresponding to the black toner obtained in the above based on the measured value obtained in the first measuring step, and a first calculating step corresponding to each color toner obtained in the fourth measuring step. The measured values to be corrected are corrected based on the measured values obtained in the third measuring process, and the corrected measured values corresponding to the respective color toners are corrected based on the measured values obtained in the fifth measuring process. Having a second operation process for normalization Toner density measuring method characterized. 2. A light-receiving element for receiving light reflected from a predetermined measurement point, a first light-emitting element disposed at a position and a posture at which regular reflection light at the measurement point is incident on the light-receiving element, and A second light emitting element disposed at a position and a position where the diffuse reflection light at the measurement point is incident on the light receiving element;
A reference reflector that reflects a part of the light emitted from the light emitting element and makes the light incident on the light receiving element, a first optical path where the reflected light at the measurement point enters the light receiving element, and the reference reflector. Using a light-projecting and receiving unit having a light-path blocking member that switches the light path so as to switch one of the second light path incident on the light-receiving element and the other to open the other. A plurality of density measurement toner images each of which includes a plurality of color toners including a black toner, are arranged on the surface, are moved on a path passing through the measurement point, and the plurality of density measurement toner images are sequentially measured. A toner image density measurement method for measuring the density of a density measurement toner image conveyed to the measurement point by a toner image conveyance body conveyed to a point, wherein the first optical path is opened by the optical path blocking member, and 2 Any of the density measurement toners executed in the first light path switching state in which the light path of the first light emitting element is interrupted and in the fourth lighting switching state in which both the first light emitting element and the second light emitting element are turned on. A sixth measuring step of measuring the light incident on the light receiving element at a timing when the image is also at a position different from the measurement point on the surface of the toner image carrier, the first optical path switching state, and the fourth measuring step. A seventh measuring step of measuring light incident on the light receiving element at a timing when the density measurement toner image of the black toner is located at the measurement point, which is executed in the lighting switching state of the first light path switching; The density measurement toner image using the black toner, which is executed in a second lighting switching state in which the first light emitting element is turned off and the second light emitting element is turned on, is located at the measurement point. A third measuring step of measuring light incident on the light receiving element in the imaging, and a density measurement by each color toner except the black toner, which is performed in the first optical path switching state and the second lighting switching state. Measuring the light incident on the light receiving element at each timing when the toner image for use is positioned at the measurement point.
And a second light path switching state in which the first light path is blocked by the light path blocking member to open the second light path, and the first light emitting element and the second light emitting element A fifth measuring step of measuring light incident on the light receiving element, the fifth measuring step being performed in a third lighting switching state in which at least the second light emitting element is turned on, and the sixth measuring step And the measured value corresponding to the black toner obtained in the seventh measuring step are respectively corrected based on the measured value obtained in the third measuring step and correspond to the black toner. A third calculating step of normalizing the measured value to be performed based on the measured value obtained by correcting the measured value obtained in the sixth measuring step, and corresponding to each color toner obtained in the fourth measuring step. Each measured value in the third measurement process. And a second operation step of normalizing each of the corrected measurement values corresponding to each color toner based on the measurement value obtained in the fifth measurement step. Toner density measurement method. 3. A light-receiving element for receiving reflected light from a predetermined measurement point, a first light-emitting element arranged at a position and a posture at which regular reflection light at the measurement point is incident on the light-receiving element, A second light emitting element disposed at a position and a position where the diffuse reflection light at the measurement point is incident on the light receiving element;
A reference reflector that reflects a part of the light emitted from the light emitting element and makes the light incident on the light receiving element, a first optical path where the reflected light at the measurement point enters the light receiving element, and the reference reflector. An optical path blocking member that switches the optical path so as to switch one of the second optical path into which the reflected light is incident on the light receiving element and open the other of the second optical path; In a state in which the second optical path is blocked by opening the second optical path, a plurality of light emitting units each including a plurality of color toners including black toner are used by using a light emitting and receiving unit having a shutter for opening and closing the first optical path. The measurement points are carried by a toner image carrier that carries the density measurement toner images on the surface in an arrayed state, moves along a path passing through the measurement points, and sequentially conveys the plurality of density measurement toner images to the measurement points. Conveyed to The toner image density measuring method of measuring the density of the density measurement toner image, the shutter is the first with blocking the second optical path by opening the first optical path by the optical path blocking member
The third optical path switching state retracted from the optical path of
The density measurement toner image is executed in a first lighting switching state in which the light emitting element is turned on and the second light emitting element is turned off, and any density measurement toner image is located at a position different from the measurement point on the surface of the toner image carrier. An eighth measurement step of measuring light incident on the light-receiving element at a certain timing; and a density measurement toner using the black toner, which is executed in the third optical path switching state and the first lighting switching state. A ninth measuring step of measuring light incident on the light receiving element at a timing when an image is located at the measurement point; a third light path switching state, wherein the first light emitting element is turned off and the second light emission is performed; The light-receiving element is executed at each timing when a toner image for density measurement of each color toner excluding the black toner is located at the measurement point, which is executed in the second lighting switching state in which the element is turned on. Of the tenth measurement process of measuring the incident light, the second by the optical path blocking member opens the first optical path
In a fourth light path switching state in which the light path is blocked and the shutter is closed, and in a third lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. An eleventh measurement step of measuring incident light to the light receiving element, wherein the light path blocking member blocks the first light path and performs the second measurement step.
A twelfth measurement step of measuring light incident on the light receiving element, the twelfth measurement step being performed in the fifth light path switching state in which the light path is opened, and in the third lighting switching state, and the ninth measurement A fourth calculating step of normalizing the measured value corresponding to the black toner obtained in the process based on the measured value obtained in the eighth measuring step; and a fourth calculating step for each color toner obtained in the tenth measuring step. Each corresponding measurement value is corrected based on the measurement value obtained in the eleventh measurement process, and each corrected measurement value corresponding to each color toner is converted to the measurement value obtained in the twelfth measurement process. And a fifth calculating step of normalizing based on the toner density measuring method. 4. A light-receiving element for receiving reflected light from a predetermined measurement point, a first light-emitting element arranged at a position and a posture at which regular reflection light at the measurement point is incident on the light-receiving element, A second light emitting element disposed at a position and a position where the diffuse reflection light at the measurement point is incident on the light receiving element;
A reference reflector that reflects a part of the light emitted from the light emitting element and makes the light incident on the light receiving element, a first optical path where the reflected light at the measurement point enters the light receiving element, and the reference reflector. An optical path blocking member that switches the optical path so as to switch one of the second optical path into which the reflected light is incident on the light receiving element and open the other of the second optical path; In a state in which the second optical path is blocked by opening the second optical path, a plurality of light emitting units each including a plurality of color toners including black toner are used by using a light emitting and receiving unit having a shutter for opening and closing the first optical path. The measurement points are carried by a toner image carrier that carries the density measurement toner images on the surface in an arrayed state, moves along a path passing through the measurement points, and sequentially conveys the plurality of density measurement toner images to the measurement points. Conveyed to The toner image density measuring method of measuring the density of the density measurement toner image, the shutter is the first with blocking the second optical path by opening the first optical path by the optical path blocking member
The third optical path switching state retracted from the optical path of
Any density measurement toner image executed in the fourth lighting switching state in which both the light emitting element and the second light emitting element are turned on is different from the measurement point on the surface of the toner image carrier. A thirteenth measurement process of measuring light incident on the light receiving element at a timing at a position, and a density measurement using the black toner, which is performed in the third optical path switching state and the fourth lighting switching state. A fourteenth measuring step of measuring light incident on the light receiving element at a timing when the toner image is located at the measurement point; a third optical path switching state, and the first light emitting element is turned off and the second light emitting element is turned off. The light receiving is performed at each timing when a toner image for density measurement by each color toner except the black toner is located at the measurement point, which is executed in the second lighting switching state in which the light emitting element is turned on. A tenth measurement process of measuring the incident light to the child, the second the optical path blocking member opens the first optical path
In a fourth light path switching state in which the light path is blocked and the shutter is closed, and in a third lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. An eleventh measurement step of measuring incident light to the light receiving element, wherein the light path blocking member blocks the first light path and performs the second measurement step.
A fifth optical path switching state in which the optical path is opened, and a twelfth measuring step of measuring light incident on the light receiving element, which is performed in the third lighting switching state. The thirteenth measurement The measurement value obtained in the process and the measurement value corresponding to the black toner obtained in the fourteenth measurement process are respectively corrected based on the measurement value obtained in the eleventh measurement process, and A sixth operation step of normalizing the corresponding measurement value based on the measurement value obtained by correcting the measurement value obtained in the thirteenth measurement step, and a process for each color toner obtained in the tenth measurement step. Each corresponding measurement value is corrected based on the measurement value obtained in the eleventh measurement process, and each corrected measurement value corresponding to each color toner is converted to the measurement value obtained in the twelfth measurement process. No. to normalize based on Toner density measuring method characterized by the and an operation process. 5. A light-receiving element for receiving light reflected from a predetermined measurement point, a first light-emitting element arranged at a position and a posture at which regular reflection light at the measurement point enters the light-receiving element, A second light-emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point enters the light-receiving element;
A reference reflector that reflects a part of the light emitted from the light emitting element and makes the light incident on the light receiving element, a first optical path where the reflected light at the measurement point enters the light receiving element, and the reference reflector. Using a light-projecting and receiving unit having a light-path blocking member that switches the light path so as to switch one of the second light path incident on the light-receiving element and the other to open the other. A plurality of density measurement toner images each of which includes a plurality of color toners including a black toner, are arranged on the surface, are moved on a path passing through the measurement point, and the plurality of density measurement toner images are sequentially measured. A toner image density measuring device for measuring the density of the toner image for density measurement conveyed to the measurement point by a toner image conveying body conveyed to a point, wherein the first light path is opened by opening the first light path by the light path blocking member; 2 The first optical path switching state in which the optical path of
The density measurement toner image is executed in a first lighting switching state in which the light emitting element is turned on and the second light emitting element is turned off, and any density measurement toner image is located at a position different from the measurement point on the surface of the toner image carrier. A first measuring means for measuring the light incident on the light receiving element at a certain timing; and a density measurement toner using the black toner, which is executed in the first optical path switching state and the first lighting switching state. A second measuring unit that measures light incident on the light receiving element at a timing when an image is located at the measurement point; a first light path switching state, and the first light emitting element is turned off and the second light emission is performed. The light incident on the light receiving element is measured at a timing when the density measurement toner image of the black toner is located at the measurement point, which is executed in the second lighting switching state in which the element is turned on. A third measuring unit, and timings at which the density measurement toner images of the respective color toners except the black toner are located at the measurement points, which are executed in the first optical path switching state and the second lighting switching state. In the fourth step, the incident light to the light receiving element is measured.
And a second light path switching state in which the first light path is blocked by the light path blocking member to open the second light path, and the first light emitting element and the second light emitting element And a fifth measuring means for measuring light incident on the light receiving element, the fifth measuring means being executed in a third lighting switching state in which at least the second light emitting element is turned on, and the second measuring means A first calculating means for normalizing the measured value corresponding to the black toner obtained in the above based on the measured value obtained by the first measuring means; and a first calculating means corresponding to each color toner obtained by the fourth measuring means. Each of the measured values is corrected based on the measured value obtained by the third measuring unit, and each corrected measured value corresponding to each color toner is corrected based on the measured value obtained by the fifth measuring unit. Having second arithmetic means for normalizing The toner concentration measuring device according to claim. 6. A light-receiving element for receiving reflected light from a predetermined measurement point, a first light-emitting element arranged at a position and a posture at which regular reflection light at the measurement point is incident on the light-receiving element, and A second light-emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point enters the light-receiving element;
A reference reflector that reflects a part of the light emitted from the light emitting element and makes the light incident on the light receiving element, a first optical path where the reflected light at the measurement point enters the light receiving element, and the reference reflector. Using a light-projecting and receiving unit having a light-path blocking member that switches the light path so as to switch one of the second light path incident on the light-receiving element and the other to open the other. A plurality of density measurement toner images each of which includes a plurality of color toners including a black toner, are arranged on the surface, are moved on a path passing through the measurement point, and the plurality of density measurement toner images are sequentially measured. In a toner image density measuring device for measuring the density of a density measurement toner image conveyed to the measurement point by a toner image conveying body conveyed to a point, the first optical path is opened by the optical path blocking member, and 2 Any of the density measurement toner images executed in the first light path switching state in which the light path is interrupted and in the fourth lighting switching state in which both the first light emitting element and the second light emitting element are turned on. A sixth measuring unit that measures light incident on the light receiving element at a timing that is different from the measurement point on the surface of the toner image carrier, the first optical path switching state, and the fourth A seventh measurement unit which is executed in a lighting switching state, measures a light incident on the light receiving element at a timing when the toner image for density measurement by the black toner is located at the measurement point,
The density measurement toner image using the black toner is executed in the first light path switching state and in a second lighting switching state in which the first light emitting element is turned off and the second light emitting element is turned on. Third measuring means for measuring light incident on the light receiving element at a timing located at a measurement point;
The toner image for density measurement of each color toner excluding the black toner, which is executed in the first optical path switching state and the second lighting switching state, enters the light receiving element at each timing at which the toner image is located at the measurement point. 4th to measure light
And a second light path switching state in which the first light path is blocked by the light path blocking member to open the second light path, and the first light emitting element and the second light emitting element A third light-emitting element in which at least the second light-emitting element is lit;
And a fifth measuring means for measuring the light incident on the light receiving element, the fifth measuring means being executed in the lighting switching state, and the measurement value obtained in the sixth measuring step and the fifth measuring means being obtained by the seventh measuring means. The measured value corresponding to the obtained black toner is
And corrects the corrected measurement value corresponding to the black toner based on the sixth measurement value.
A third calculating unit for normalizing based on the corrected measured value obtained by the measuring unit, and a third measuring unit that calculates each measured value corresponding to each color toner obtained by the fourth measuring unit by the third measurement. A second calculating means for correcting based on the measured value obtained by the means and normalizing each corrected measured value corresponding to each color toner based on the measured value obtained by the fifth measuring means. A toner concentration measuring device, characterized in that: 7. A light-receiving element for receiving light reflected from a predetermined measurement point, a first light-emitting element disposed at a position and a position where regular reflection light at the measurement point enters the light-receiving element, and A second light-emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point enters the light-receiving element;
A reference reflector that reflects a part of the light emitted from the light emitting element and makes the light incident on the light receiving element, a first optical path where the reflected light at the measurement point enters the light receiving element, and the reference reflector. An optical path blocking member that switches the optical path so as to switch one of the second optical path into which the reflected light is incident on the light receiving element and open the other of the second optical path; In a state in which the second optical path is blocked by opening the second optical path, a plurality of light emitting units each including a plurality of color toners including black toner are used by using a light emitting and receiving unit having a shutter for opening and closing the first optical path. The measurement points are carried by a toner image carrier that carries the density measurement toner images on the surface in an arrayed state, moves along a path passing through the measurement points, and sequentially conveys the plurality of density measurement toner images to the measurement points. Conveyed to And the toner image density measuring device for measuring the density of the density measuring a toner image, wherein the shutter is the first with blocking the second optical path by opening the first optical path by the optical path blocking member
The third optical path switching state retracted from the optical path of
The density measurement toner image is executed in a first lighting switching state in which the light-emitting element is turned on and the second light-emitting element is turned off. An eighth measuring means for measuring the light incident on the light receiving element at a certain timing; and a toner for density measurement by the black toner, which is executed in the third optical path switching state and the first lighting switching state. Ninth measuring means for measuring light incident on the light receiving element at a timing when an image is located at the measurement point; third light path switching state, and the first light emitting element is turned off and the second light emission is performed. The light-receiving element is executed at each timing when a toner image for density measurement of each color toner excluding the black toner is located at the measurement point, which is executed in the second lighting switching state in which the element is turned on. Of a tenth of measuring means for measuring the incident light, the second by the optical path blocking member opens the first optical path
A fourth light path switching state in which the light path is blocked and the shutter is closed, and a third lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. An eleventh measuring unit for measuring incident light to the light receiving element, wherein the optical path blocking member blocks the first optical path and performs the second measurement.
A fifth optical path switching state in which the optical path is opened, and a twelfth measuring means for measuring incident light to the light receiving element, which is executed in the third lighting switching state, and the ninth measurement A fourth calculating means for normalizing the measured value corresponding to the black toner obtained by the means on the basis of the measured value obtained by the eighth measuring means; and a fourth calculating means for each color toner obtained by the tenth measuring means. Each corresponding measured value is corrected based on the measured value obtained by the eleventh measuring unit, and each corrected measured value corresponding to each color toner is converted to a measured value obtained by the twelfth measuring unit. And a fifth calculating means for normalizing based on the toner density. 8. A light-receiving element for receiving light reflected from a predetermined measurement point, a first light-emitting element arranged at a position and a posture at which regular reflection light at the measurement point is incident on the light-receiving element, A second light-emitting element disposed at a position and a posture at which the diffuse reflection light at the measurement point enters the light-receiving element;
A reference reflector that reflects a part of the light emitted from the light emitting element and makes the light incident on the light receiving element, a first optical path where the reflected light at the measurement point enters the light receiving element, and the reference reflector. An optical path blocking member that switches the optical path so as to switch one of the second optical path into which the reflected light is incident on the light receiving element and open the other of the second optical path; In a state in which the second optical path is blocked by opening the second optical path, a plurality of light emitting units each including a plurality of color toners including black toner are used by using a light emitting and receiving unit having a shutter for opening and closing the first optical path. The measurement points are carried by a toner image carrier that carries the density measurement toner images on the surface in an arrayed state, moves along a path passing through the measurement points, and sequentially conveys the plurality of density measurement toner images to the measurement points. Conveyed to And the toner image density measuring device for measuring the density of the density measuring a toner image, wherein the shutter is the first with blocking the second optical path by opening the first optical path by the optical path blocking member
The third optical path switching state retracted from the optical path of
Any density measurement toner image executed in the fourth lighting switching state in which both the light emitting element and the second light emitting element are turned on is different from the measurement point on the surface of the toner image carrier. A thirteenth measuring means for measuring light incident on the light-receiving element at a timing at a position, and a density measurement by the black toner, which is executed in the third optical path switching state and the fourth lighting switching state. A fourteenth measuring means for measuring light incident on the light receiving element at a timing when the toner image is located at the measurement point; a third light path switching state, wherein the first light emitting element is turned off and the second light emitting element is turned off; The light receiving is performed at each timing when a toner image for density measurement of each color toner except the black toner is located at the measurement point, which is executed in the second lighting switching state in which the light emitting element is turned on. A tenth means for measuring the incident light to the child, the second the optical path blocking member opens the first optical path
In a third light path switching state in which the light path is blocked and the shutter is closed, and in a fourth lighting switching state in which at least the second light emitting element of the first light emitting element and the second light emitting element is turned on. An eleventh measuring unit for measuring incident light to the light receiving element, wherein the optical path blocking member blocks the first optical path and performs the second measurement.
A fifth optical path switching state in which the optical path is opened, and a twelfth measuring means for measuring light incident on the light receiving element, which is executed in the third lighting switching state, and the thirteenth measurement. The measured value obtained in the process and the measured value corresponding to the black toner obtained by the fourteenth measuring means are respectively corrected based on the measured value obtained by the eleventh measuring means, and the black toner is corrected. A sixth calculating means for normalizing a corresponding measured value based on the measured value obtained by correcting the measured value obtained by the thirteenth measuring means; and a color calculating means for each color toner obtained by the tenth measuring means. Each corresponding measured value is corrected based on the measured value obtained by the eleventh measuring unit, and each corrected measured value corresponding to each color toner is converted to a measured value obtained by the twelfth measuring unit. No. to normalize based on The toner concentration measuring apparatus characterized by having a computing means.