JPH04156479A - Toner powder image thickness measuring device and color printing device for the same - Google Patents

Abstract

PURPOSE:To enable dispersion of light by toner powder images to be prevented and further to enable the toner powder image to be measured as they are by a method wherein a laser light source, a slit for removing dispersion of reflected light from the toner powder images are provided and a thickness of the toner powder images is measured at a light receiving position of a light receiving part. CONSTITUTION:Measuring light is radiated against toner powder images by a laser light source 190. Dispersion of reflected light from the toner powder images is removed by a slit 191. The reflected light passed through the lit 191 is received at a light receiving part 192 and then a thickness of the toner powder images is measured at the light receiving position of the light receiving part 192. In this way, laser beam is used as a measuring light for preventing a dispersion of light and the slit 191 is disposed in order to cut the reflected dispersion light. With such an arrangement, it is possible to prevent any dispersion of light caused by the toner power images and then to measure a thickness accurately while the toner powder images being kept as they are.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Conventional technology Problems to be solved by the invention (Fig. 12) Means for solving the problems (Fig. 1) Working examples (a) l = Explanation of Nana powder image thickness measuring device (Figs. 2 to 4) (1))) Description of another embodiment of Nana powder image thickness measuring device (Fig. 5) (C) Color printing Description of the apparatus (FIGS. 6 to 11) (d) Description of other embodiments Effects of the invention [Summary] Thickness measurement of toner powder image that measures the thickness of toner powder image formed on a support Concerning a device and a color marking device using the same.

The purpose is to measure the amount of toner adhesion and adjust the printing process based on the measurement results.

A toner powder image thickness measuring device for measuring the thickness of a toner powder image on a support, the device includes a laser light source that irradiates the toner powder image with measurement light, and a laser light source that irradiates the toner powder image with measurement light; With slits to remove scattering.

and a light receiving section that receives the reflected light that has passed through the slit, and measures the thickness of the toner powder image based on the light receiving position of the light receiving section.

[Industrial application field]

The present invention relates to a toner powder image thickness measuring device for measuring the thickness of a toner powder image formed on a support, and a color printing apparatus using the same.

As a color printing device that uses color toner.

There are electrophotographic systems, electrostatic recording systems, etc., and they are used in printers, facsimile machines, copying machines, etc.As is well known, electrophotographic recording devices have an image forming process and a recording paper conveyance process, and one image The formation process includes
Includes electrostatic latent image formation processes, electrostatic latent image development processes, transfer processes and fusing processes.

The electrostatic latent image formation process involves optically projecting a recorded image onto a photoreceptor drum or belt.
Alternatively, an electrostatic latent image is formed by applying a charge to a dielectric drum.

In the electrostatic latent image development process, the electrostatic latent image is developed by electrostatically depositing toner as a recording medium on the electrostatic latent image thus formed.

The toner used for development is transferred to the recording paper in a transfer process, and then the transferred toner is fixed to the recording paper in a fixing process.

In such a device, the amount of toner adhesion varies depending on the environment in which the device is used, resulting in nine hue changes.

Therefore, it is necessary to measure the amount of l-ner deposited and adjust the process conditions based on this measurement.

[Conventional technology]

In the conventional technology, it is specified that the device is operated under a constant environment of room temperature and humidity (room temperature and normal humidity) and air conditioning, and it is assumed that the output image will not change due to changes in the environment.

For this reason, conventionally, each color toner is developed during initialization after the power is turned on, and only the presence or absence of a toner image is checked. In this method, a toner image of a certain pattern is created on a photoreceptor or an intermediate transfer member, and the time it takes for the toner image to pass through a certain measurement position is measured. The presence or absence of a toner image is confirmed by checking the presence or absence of reflected light from the light irradiated onto the photoconductor or intermediate transfer body.l = When there is no toner image, there is reflected light, and when there is a toner image, there is reflected light. It can be confirmed because there is no reflected light.

[Problem to be solved by the invention]

By the way, in an electrophotographic recording device that uses color toner, the amount of charge of the color toner, the sensitivity of the photoreceptor, the transfer efficiency, etc. fluctuate due to changes in the usage environment of the device, resulting in a decrease in the color reproducibility of the output image, that is, the image quality. Deterioration occurs. The deterioration caused by these fluctuations is ultimately integrated as a fluctuation in the amount of toner adhering to the recording paper.

This variation in toner adhesion amount depends on the characteristics of each color toner (environmental characteristics of the amount of charge, etc.), and is not variable. In other words, environmental changes appear not only in image density but also in color (change in hue). Black toner also has environmental fluctuations, but color toner has more environmental fluctuations. In particular, the variation in the amount of charge is as large as about 1.5 to 3 times that of black toner, and this is immediately reflected in the variation in the amount of toner adhesion.

For example, in the case of yellow toner, the change in image density with respect to the amount of toner adhesion is shown in Figure 12.
It can be seen that the image density also increases as the amount of toner adhesion increases.

When outputting a color image, the secondary color is determined by the proportion of the adhesion amount of each color toner.

As shown in FIG. 12, when the toner adhesion amount changes, it can be easily inferred that not only the image density but also the color changes.

Moreover, the stable range of image density relative to the amount of toner adhesion is narrow, and if the allowable amount of density reduction is set to 80 to 90% of the maximum image density, it will be at least 5.5 (g/nl'') or higher.
Looking at the allowable range from the maximum toner adhesion amount, the adhesion variation is 2.
It can be seen that the width is 5 (g/ni''), which is extremely narrow.

Furthermore, this toner adhesion amount is not the toner weight.

When converted to toner layer thickness, the variation range is approximately 10 to 20 (μm)
Therefore, it depends on the thickness of one toner.

Conventional technology stipulates that the device should be operated in a constant air-conditioned environment at room temperature and humidity (room temperature and normal humidity), so there is no change in the environment and, therefore, there is no change in the toner image. .

However, if it is left for a certain period of time or if it is output first thing in the morning, it is likely to be output in a different color than if it is output continuously. This is because the development conditions (mainly the amount of charge) for each toner have changed, so the amount of toner adhesion before transfer to the recording paper is different for each color or the ratio of these is different from when outputting in a continuous state. .

As described above, the conventional technology has a problem in that it is impossible to detect variations in the amount of toner adhesion due to changes in environmental conditions, and the two-image change cannot be detected.

Therefore, it is an object of the present invention to provide a toner powder image thickness measuring device capable of measuring the amount of toner adhesion.

Another object of the present invention is to provide a color printing device that can measure the amount of toner adhesion and adjust the printing process so that the amount of toner adhesion is constant.

[Means to solve the problem]

FIG. 1 is a diagram showing the principle of the present invention.

In claim (1) of the present invention, as shown in FIG. 1 (5).

A toner powder image thickness measuring device for measuring the thickness of the toner powder image on the support body 100, which includes a laser light source 190 that irradiates the toner powder image 1n with measurement light, and the toner powder image 1n.
The thickness t of the toner powder image 1n is determined by the light receiving position of the light receiving part 192. It is characterized by measuring.

According to claim (2) of the present invention, in claim 2 (1), the measurement light of the laser light source 190 is irradiated to the toner powder image 1n in an angle range of 400 to 600 from the perpendicular to the toner powder image 1n. It is characterized by

Claim (3) of the present invention is characterized in that, in Claim (1), the beam diameter of the measurement light from the laser light source 190 is set to be smaller than the average particle diameter of the toner powder 1n.

In claim (4) of the present invention, as shown in FIG. 1(B).

An image carrier 100 on which an electrostatic latent image is formed, and the image carrier 1
and a latent image forming section 102 that forms an electrostatic latent image on 00.

It has a plurality of developing devices 103 each of which develops the electrostatic latent image with toner of a different color.

In a color printing apparatus that performs color printing by overlapping toners of a plurality of colors, a thickness measuring device 19 is provided to measure the thickness of a single color toner powder image formed by the plurality of developing devices 103, and the thickness The mark 1i is determined by the measurement result of the measuring device 19.
It is characterized by adjusting the i1 condition.

According to claim (5) of the present invention, in claim (4), the thickness measuring device 9 includes a laser light source 190 that irradiates the toner powder image with measurement light, and a laser light source 190 that irradiates the toner powder image with measurement light; and a slit 191 for removing scattering.

A light receiving unit 1 that receives the reflected light that has passed through the slit 191
92, and is characterized in that the thickness of the toner powder image is measured based on the light receiving position of the light receiving section 192.

In claim (6) of the present invention, in claim (4), 1
Claims of the present invention are characterized in that one image carrier 100 and a plurality of developing units 103 are provided, and only one thickness measuring device 19 is provided for a plurality of desired colors. Then, in claim (4), the developing device 1.03 is adjusted according to the measurement result of the thickness measuring device 19.
The present invention is characterized in that it is provided with a control section 21 that controls the developing bias voltage.

[Effect]

The toner image before transfer is formed on the photoreceptor or intermediate transfer member, and the condition is to measure the thickness in that state. In particular, methods of fixing toner by applying heat or pressure not only damage the photoreceptor or intermediate transfer member, but also impede cleaning of the fixed toner image. Therefore.

In claim (1) of the present invention, optical measurement is used to measure the thickness of the toner powder image.

However, when measuring the layer thickness in the powder state, optical measurement is difficult due to scattering of the measurement light. Furthermore, color toners, especially those that express secondary colors through overlapping, are transparent so that the color of the underlying toner can reach the surface, so the measuring light passes through the inside of the toner. That must also be taken into consideration.

Therefore, in order to prevent light scattering, a laser beam was used as the measurement light, and a slit [9] was provided to cut off the reflected and scattered light.

In claim (2) of the present invention, the irradiation angle of the measurement light is set at 40° to
By setting it to 60', the 2 reflectance can be made more consistent.

Detection efficiency is improved.

In claim (3) of the present invention, the beam diameter of the measuring light is set to be smaller than the average particle diameter of the toner particles.

We aimed to reduce measurement variations by averaging the unevenness of the toner without being affected by the toner particle size.

In claim (4) of the present invention, since the color printing apparatus is provided with the thickness measuring device 19, it is possible to adjust the amount of toner adhesion due to environmental changes.

In claim (5) of the present invention, since the thickness detector 19 performs optical measurement, the thickness of the toner layer formed on the image carrier 1.00 can be accurately measured as a powder image. .

In claim (6) of the present invention, since a plurality of thickness measuring devices 19 are provided, the thickness can be measured independently for each desired color.

In the claim of the present invention, since the developing bias voltage is controlled according to the measured layer thickness, it is possible to automatically adjust the toner layer thickness to a desired value in response to environmental changes.

〔Example〕

(a) Description of toner powder image thickness measuring device FIG. 2 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2(5) is an overall configuration diagram, FIG. 2(B) is a detailed diagram of the detection element, and FIG. 2(C) is an output characteristic diagram.

As shown in Figure 2, the light source consists of a semiconductor laser 190, which emits laser light with uniform wavelength, and a lens 1.
Reference numeral 93 condenses the emitted light from the semiconductor laser 190 into measurement light having a predetermined beam diameter of 80 μm.

The slit 191 is provided so that the long axis of the slit is in the direction in which the reflected light moves due to variations in the toner layer thickness.

It is provided to eliminate scattering of reflected light from the toner powder image.

The detection element (light-receiving section) 192 is made up of 16 light-receiving elements arranged in parallel, as shown in FIG. 2(B).

The light-receiving element that is hit by the reflected light emits an output.

The measurement operation will be explained using FIG.

The toner powder image 1n formed on the support (photoreceptor or intermediate transfer member) 100 forms a layer with a certain filling rate. The incident light emitted from the light source 190 is applied to the photoreceptor or intermediate transfer member 10.
The toner particles enter the toner powder image 1n at an angle of θ1 from the normal line of 0. Here, assuming that there is only one layer of toner powder image tn, the second reflected light beam br2 travels in the opposite direction to the incident light at an angle θ2 with respect to the normal line of the photoreceptor or intermediate transfer member 100 and irradiates the detector 192. Further, the angles θ1° θ2 between the incident light and the reflected light with the normal line are considered to be the same if the beam diameter is very large relative to the particle diameter of the powder. Also.

When there is no toner powder image 1n, the incident light is reflected on the photoreceptor or intermediate transfer member 1.00, and the reflected light 1) and 3 enter the detector 192 as is.Furthermore, the thicker the toner powder image 1n, the more the reflected light The point where the light 1) rl reaches the detector 192 is the reflected light from the photoreceptor or the intermediate transfer member 1.00, 3
move further away.

The length l of movement on this detector 192 is the length l of the toner powder image 1
Let the thickness of n be t.

l=2・t*tan (θI)...
・・・・・・・・・・・・・・・(1) Howl. In other words,
Since the incident angle θI of the measurement light is known, the toner layer thickness can be immediately determined by determining the moving distance of the laser beam on the detector 192.

t-(l/2)・taIf'(θ1)...
(2) That is, as shown in FIG. 2 (q), the toner layer is thin depending on the output position of the detector 192 (the position of the light receiving element with output). You can determine whether it is thick or not.

In FIG. 2 (q, the light receiving element (16) on the right side of the detector 192
) has the thinnest layer thickness, and the layer thickness increases toward the left.Next, the beam diameter of the measurement light will be explained.

The measurement light emitted from the semiconductor laser 190 first passes through the lens 193.
The beam diameter is narrowed down and irradiated onto the surface of the toner powder image. This value is due to the fact that the reflected light from the powder image 1n made up of toner with a particle size of a few μm is not affected by the toner particle size and enters the detector 92 in an averaged state, so it is not focused very much. Instead, it was made into 8 layers with a diameter of 80 μm.

That is, the beam diameter is smaller than the l-ner average particle diameter.

Further, the reason why a laser beam was used as the measurement light was for the first reason.

When white light was used as the measurement light, there was almost no reflected light to the light receiver, and the reflected light spread on the light receiving element so much that the measurement could not be performed accurately. this is.

Because white light contains many different wavelengths,
This is because the light is scattered because the reflection on the toner powder image surface differs depending on the wavelength, and it can be seen that laser light with the same wavelength is superior as the measurement light.

FIG. 3 shows the angle-dependent characteristics of reflectance in a toner powder image. As a result of measuring the angle θ1 of the incident light and the angle θ2 of the detector at positions facing each other at the same angle from the normal direction of the toner powder image surface, it was found that θ1. The reflectance is highest when θ2 is 45°. In other words, it can be seen that the incident light enters the detector most easily. At the same time, it can be seen that the incident light does not enter the inside of the toner powder image and is largely reflected on the surface of the powder image, indicating that the light is not absorbed and no scattering occurs inside. From this, it can be said that it is good to irradiate the incident light in the range of 400 to 600 degrees from the normal direction of the powder image surface.

In the toner powder image thickness detector with this configuration, when the thickness of the toner powder image was measured with the measurement light irradiation angle set at 45 degrees, the thickness of the toner powder image with single color toner was 0 to 6.
It fluctuates in the range of 0 (maX) μm.

It was confirmed that the detection element 192 was moved by 120 μm. Furthermore, in the case of black toner, there was almost no reflected light from the toner powder image, making measurement impossible. Therefore, when we investigated the relationship between the amount of toner adhesion and the image density for black toner, as shown in FIG. 4, the image density rapidly increases with respect to the amount of toner adhesion and reaches the saturation density. While other color toners require an acceptable range of at least 5.5 (g/m'), black toner requires at least 3.5 (g/m').
More than that is fine.

The range from the maximum toner adhesion amount is 5.5 (g/m'
), which is twice that of other color toners. From this, it can be said that it is not necessary to control or measure the amount of toner adhesion for black toner.

That is, in a full-color printer of yellow (Y), magenta (M), cyan (C), and black (K), it is possible to control and measure the amount of toner adhesion for three colors other than black toner.

(b) Description of another embodiment of the l=nana image thickness measuring device FIG. 5 is a diagram illustrating another embodiment of the toner powder image thickness measuring device of the present invention.

The configuration of this embodiment is such that, as shown in FIG. 5, a convex mirror 194 is provided before the reflected light enters the slit 191 on the detector 192 side of the first embodiment. This convex mirror 194
In order to more accurately detect the movement of the reflected light caused by the movement of the reflected light in the normal direction due to the fluctuation of the toner powder image, the width of the detection element 19 is further increased.
In the first example, when the incident angle of the measurement light is set at 45°, it has been confirmed that the detection element 192'2 is moved by 120 μm, but in the second example, With various configurations, the movement width can be freely selected depending on the curvature of the convex mirror 194.

In other words, the widening of the movement width on the detection element 192 makes it possible to measure minute variations in the thickness of the L-ner powder image.
By preparing a variety of curvatures and exchanging them, the resolution can be changed.

When the convex mirror 194 is inserted into the measurement system, the two reflected lights may spread, but the path of the first reflected light is the same as the second convex mirror 194.
This can be solved by inserting a condenser lens between the two.

(C) Description of Color Printing Apparatus FIG. 6 is a block diagram of an embodiment of the color printing apparatus of the present invention, and shows an electrophotographic color printer using an LEI array.

This printer includes four sets of recording units 10-13.

Each of the recording units 10 to 13 includes a photosensitive drum 1.
00, a charger 10 for pre-charging the photosensitive drum 100, and an LED array 102 having one line of LEDs for exposing the photosensitive drum 100 with a light image.

a developing device 103 that develops the latent image on the photosensitive drum 100;

A transfer device that transfers the toner image on the photosensitive drum 100 onto paper]
04 and cleaner 1.05 for cleaning the photosensitive drum 100.
It performs electrophotographic recording to form an image using toner on the photosensitive drum 1001.

14 is a fixing device which melts and fixes the toner on the paper that has been transferred four times using heat.

Reference numeral 15 is a paper cassette for storing paper to be recorded, and 16 is a pickup roller for taking out the paper from the paper cassette 15.

Reference numeral 17 indicates a recording paper conveyance system, which causes the paper taken out by the pickup roller 16 to pass through four sets of recording units 1() to 3, and sends it to the fixing device 14. Reference numeral 18 indicates a stacker; This is for storing the paper ejected from the paper 14.

19 is the aforementioned toner powder image thickness detector.

Photosensitive drum 100 with non-black recording units 10 to 12
It is provided at the lower part of the cleaner 105 opposite to the cleaner 105.

The operation of this color printer is quadratic.

Yellow (Y), magenta (M), and cyan (C) are applied to the developing devices 103 of each of the recording units 10 to 13, respectively.

Add flat (K) color developer.

The paper in the paper cassette 15 is taken out by a pickup roller 16 and is transported under each of the recording units 10 to 13 by a two-paper transport system 17.

On the other hand, in each of the recording units 10 to 13, electrophotographic recording is performed, and an image is formed on the photosensitive drum 100 using a developer of each color.

When the paper comes under each photosensitive drum 100, the toner image on the photosensitive drum "00" is transferred onto the paper by each transfer device 1.04.

The paper that has been transferred four times is transferred to the fixing device 14.

The heat melts and fixes the toner, and outputs it to the stacker 18 .

Since this printer uses an LED array, it is solid-state scanning and does not require any mechanically driven parts.
Also, the optical path length can be shortened.

The equipment can be made smaller, and furthermore, due to advances in semi-dedicated technology, 2
It has the advantage of being cheap.

A small printer can be realized.

Also, electrophotography allows for high-speed recording.

A high-speed color printer can be realized.

Furthermore, since each recording unit performs recording operations in parallel in a pipeline manner, high-speed color recording is possible.

In such color printers, the amount of toner adhesion varies due to environmental changes, causing color changes in one image.

Therefore, it is necessary to control the amount of toner adhesion due to environmental changes.

Therefore, a thickness measuring device 19 is provided in the recording units 10 to 12, and the thickness of the toner powder image is measured.
This feeds back to each process so that it is the same as the humidity.

Here, as shown in FIG. 4 above, the image density of black toner is saturated even with a small amount of toner adhesion, and black toner does not constitute a secondary color with other color toners, so toner There is no need to grasp variations in the amount of adhesion, and there is no need to provide the thickness measuring device 19 to the black recording unit 13. Since this thickness measuring device 19 measures the thickness of the toner powder image, it is necessary to provide it between the developing device 103 to which the L-toner is attached and the cleaner 105 to remove the toner.

In particular, the measurement device 19 is likely to be contaminated by excess toner immediately below the developing device 103, resulting in measurement errors.

It is desirable to provide it on the cleaner 105 side as shown in FIG.

FIG. 7 is a block diagram of an embodiment of the present invention.

FIG. 7 is a diagram of the overall configuration, and FIG. 7 (I3) is a diagram of the measurement circuit.

In the figure, the same parts as those shown in FIGS. 1, 2, and 6 are indicated by the same symbols. In FIG. 7 (5), 220 is a measuring circuit, and each recording unit 10 ~12
Converts the output of the light receiving section 192 of the measuring instrument 19 into serial data and outputs it to a control section 21, which will be described later. 21 is a control section, which is composed of a microprocessor (MPU) and a host control section (not shown). Each recording unit 10 to I3 is controlled according to instructions from
The position of the light receiving element of the reflected light is determined from the output of , the toner layer thickness is detected from this, and the developing bias voltages Vby, Vbm, and Vbc of each developing device 103 are controlled.

The measurement circuit 20 scans the voltage outputs of the 16 light receiving elements of the light receiving section 192, as shown in FIG. 7 (I3).

It has a scanning circuit 20a that converts to serial output, and an analog-to-digital converter (A, DC) 20b that converts serial analog output to a digital value, and each light receiving element #1 to #
16 voltage outputs as serial digital signals MPU
21.

The MPU 21 receives this serial digital signal.

The voltage output of each light receiving element 41.1 to #-16 is compared, and the light receiving element with the maximum output voltage is determined as shown in FIG. 2 (q), and the toner layer thickness is calculated from this.

FIG. 8 is a process flow diagram of an embodiment of the present invention, FIG. 9 is a process flow diagram of the process adjustment process, and FIGS. 10 and 11 are operation explanatory diagrams of an embodiment of the present invention.

This will be explained along with FIG.

■ When the power is turned on, the device is on standby and a sign [Waiting for CIJ instruction.

(2) When a print instruction arrives from the host control unit to the MPU 21, it is determined whether initial printing or continuous printing is to be performed.

(2) In the case of continuous printing, the MPU 21 causes the pinocrawler 16 to start the recording paper PP from the cassette 15 and transport it by the transport system 17.

Then, the MPU 21 processes the process (
P1 process).

As a result, in the recording unit 10, as shown in FIG. 10, the photosensitive drum 100 is negatively charged to Vs (for example, negative) by the charger 101 (FIG. 10(A)).

LED7L/102-111-Light image exposure (Figure 10(B)).

The toner (negative toner) is developed using the developing bias potential Vd (for example, -400 volts) determined by the developing device 1.03. 10(D)), the toner image is transferred onto the recording paper PP by the transfer device 104 (FIG. 10 □□□).

After a predetermined period of time has elapsed after the start of the PI process, the MPU 21 starts each of the recording unit processes 11, 12, and 13 (referred to as P2, P3, and P4 processes).

Then, the fixing device 14 fixes the toner image on the recording paper 1) and outputs it to the stacker 18.

■ The MPU 21 checks whether it has finished, and if it has finished, prints.
If not finished, return to step ■.

■ On the other hand, if step ■ determines that it is initial printing.

The MPU 21 performs toner layer thickness detection and process adjustment processing.

First, the MPU 21 operates the P1 process of the recording unit 10 to form a toner powder image on the photosensitive drum 100. At this time, no transfer process is performed.

Therefore, the toner powder image on the photosensitive drum 100 faces the thickness measuring device 19 .

The MP'U21 causes the aforementioned laser light source 190 to emit light,
The output of the light receiving section 192 is scanned by the scanning circuit 20a, AI) C20b.
, the light receiving position is determined, and the toner layer thickness is calculated.

As shown in FIG. 9, the calculated toner layer thickness is compared with the reference toner layer thickness (at normal temperature and normal humidity) to determine whether the toner layer thickness is just right (good), thin, or thick.

When the toner layer thickness is thin, the MPU 21 lowers the developing bias voltage Va (Vby) (increases the potential difference with respect to the latent image) as shown in FIG. Let the adhesion amount be dog.

If the toner layer thickness is good, the developing bias voltage vd (vby) is left unchanged as shown in FIG. 11('B).

When the toner layer thickness is thick, M
The PU 21 raises the developing bias voltage Vd (Vby) as shown in FIG. 11 (q) (to reduce the potential difference with respect to the latent image),
It is set in the developing device 130, and the amount of toner adhesion is controlled to be small.

In addition, if the toner layer thickness is thin, the toner charge amount is more than normal temperature and humidity, and if the toner layer thickness is thick,
This is a case where the l-ner charge amount is smaller than that at normal temperature and normal humidity.

In this way, the developing bias is adjusted and the toner layer thickness is controlled to be the same as that at room temperature and humidity.

Thereafter, in the same manner, control is performed for recording unicode) 1.1.12, and the process proceeds to step (2), normal printing.

In this way, before starting the initial mill 1N11, the toner layer thickness of each color of yellow, magenta, and cyan is measured, the development bias is adjusted, the toner layer thickness is controlled to the one at room temperature and humidity, and printing is started. Start.

(d) Description of other embodiments In addition to the embodiments described above, the present invention can be modified as follows.

(2) The light receiving section 192 of the thickness measuring instrument is not limited to the one having the configuration shown in FIG.

■ Color printing equipment is not limited to the one shown in Figure 6, but also the one shown in Figure 1 (
The present invention can also be applied to systems in which a plurality of developing units are provided for one photosensitive drum as in (g)), and in this case, only one thickness measuring device is required.

■ I explained using an electrophotographic color printing device.

An electrostatic recording method may also be used.

■ Although the recording process is automatically controlled, the measurement results from the thickness measuring device may be displayed and adjusted manually.

(2) Although the developing bias is controlled as part of the recording process, the charging voltage and exposure amount may also be controlled.

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention.

These are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to claim (1) of the present invention.

It has the following effects.

■ The toner powder image can be reliably measured in its original form0. ■ The scattering of light due to the toner powder image can also be prevented, allowing accurate detection.

(2) According to claim (2), detection efficiency can be further improved.

■ In claim (3), the unevenness of the toner is averaged.

Measurement variations can be reduced.

Further, according to claim (4) of the present invention, the following effects are achieved.

■ Since the color marking device is equipped with a thickness measuring device, changes in toner adhesion amount due to environmental changes can be adjusted.
Stable color printing is possible regardless of the environment.

(2) In claim (5), the toner layer thickness can be measured as is in the powder image.

(2) In claim (6), the thickness can be measured independently for each desired color.

(2) According to claim (7), automatic control of the toner layer thickness can be realized.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention. FIG. 2 is an explanatory diagram of the first embodiment of the present invention. FIG. 3 is a diagram showing the angle dependence of the reflectance in FIG. 2. FIG. 4 is a diagram showing the relationship between the toner adhesion amount of black toner and image density. FIG. 5 is an explanatory diagram of another embodiment of the present invention. FIG. 6 is a block diagram of a color printing apparatus according to an embodiment of the present invention. FIG. 7 is a block diagram of an embodiment of the present invention. FIG. 8 is a processing flow diagram of an embodiment of the present invention. FIG. 9 is a flow diagram of the process adjustment process shown in FIG. 8. FIG. 10 and FIG. 11 are explanatory diagrams of the operation of an embodiment of the present invention. FIG. 12 is a diagram showing the relationship between toner adhesion amount and image density. In the figure, 19...thickness measuring device. 21...control unit. 100...Support (image carrier). 102...Latent image forming section. 103...Developer. 190...Laser light source. 191... Suri. 192... Light receiving section.

Claims (7)

[Claims] (1) A toner powder image thickness measuring device for measuring the thickness of the toner powder image on the support (100), comprising a laser light source (190) that irradiates the toner powder image with measurement light; It has a slit (191) for removing scattering of reflected light from the toner powder image, and a light receiving section (192) that receives the reflected light passing through the slit (191), the light receiving section (192) A toner powder image thickness measuring device, characterized in that the thickness of the toner powder image is measured by the light receiving position of the toner powder image. (2) The toner powder image according to claim 1, wherein the measurement light of the laser light source (190) is irradiated onto the toner powder image within an angle range of 400 to 600 from a perpendicular to the toner powder image. thickness measuring instrument. (3) The toner powder image thickness measuring device according to claim 1, wherein the beam diameter of the measuring light from the laser light source (190) is larger than the average particle diameter of the toner powder. (4) An image carrier (100) on which an electrostatic latent image is formed, and a latent image forming section (100) that forms an electrostatic latent image on the image carrier (100).
102); and a plurality of developing devices (103) that each develop the electrostatic latent image with toner of a different color, and performs color printing by superimposing toner of a plurality of colors. A thickness measuring device (19) is provided for measuring the thickness of the toner powder image of a desired color formed by the developing device (103), and printing conditions are adjusted based on the measurement results of the thickness measuring device (19). A color printing device using a toner powder image thickness measuring device. (5) The thickness measuring device (19) includes a laser light source (190) that irradiates the toner powder image with measurement light.
), a slit (191) for removing scattering of the reflected light from the toner powder image, and a light receiving section (192) that receives the reflected light passing through the slit (191), the light receiving section 5. A color printing apparatus using the toner powder image thickness measuring device according to claim 4, wherein the thickness of the toner powder image is measured based on the light receiving position of (192). (6) The image carrier (100) and the latent image forming section (10
2), a plurality of the thickness measuring devices (19) are provided corresponding to a plurality of desired colors (a plurality of the developing devices (103) are provided on one image carrier (100)). 5. A color printing apparatus using a toner powder image thickness measuring device according to claim 4, wherein only one thickness measuring device (19) is provided. (7) The toner powder according to claim (4), further comprising a control section (21) that controls the developing bias voltage of the developing device (103) according to the measurement result of the thickness measuring device (19). Color printing equipment using an image thickness measuring device.