JPH11184317A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device of which constitution is simple and inexpensive and which prevents erroneous detection and erroneous discrimination caused by the deterioration and soiling of the light source of a glossiness sensor and is provided with the glossiness sensor capable of maintaining discrimination sensitivity excellent. SOLUTION: The gloss data of the base of recording paper 102 is fetched in, and the average value Vm of the gloss data is calculated by an arithmetic circuit 206. The average value Vm is read out to a comparator circuit 207 and is compared whether to be equal to or above a normal value or not by a ROM 207. It is discriminated as an OHT when the average value Vm is higher than the normal value. Also, when it is lower than the normal value, a correction data Vc stored at a RAM 205 is read out, and a relative value (Vm/Vc) is calculated by the arithmetic circuit 206. The relative value is compared with a specified value A. When the relative value is higher than the specified value A, it is compared with the OHT, and when it is lower, it is compared with the specified value B (A>B). When the relative value is lower than a specified value B, it is discriminated as a regular paper, and when it is higher, it is discriminated as a gloss paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic system or an electrostatic recording system such as a color printer or a color copying machine, and relates to a material of a recording paper used in the image forming apparatus. The method is characterized in that the type of recording material is determined by measuring the glossiness.

[0002]

2. Description of the Related Art In general, there is a color image forming apparatus as an apparatus requiring image density control. This type of color image forming apparatus, for example, repeats a process of transferring a recording image formed by charging, exposing, and developing on a photosensitive drum onto an intermediate transfer belt a plurality of times, and finally, a multi-color superimposed image on a recording paper. Is retransferred to obtain a color image.

Prior to forming an image on a recording sheet, the color image forming apparatus includes a gloss sensor as glossiness detecting means for determining the type of the recording sheet based on the glossiness of the surface. Some have.

The gloss sensor is used to detect the recording paper and the image in accordance with the glossiness of the recording paper in order to perform optimal printing, and to print the image on a transparent original such as OHT (transparent paper for overhead project). It is used to control the process so that light is transmitted when it is performed.

The gloss sensor is composed of a light-emitting light source and two light receiving elements, measures the gloss of the recording paper, determines the type of the recording paper based on the measured gloss data, and determines the type of each high-voltage power supply and fixing device. Printing conditions such as speed and temperature were changed.

Further, recording paper having transparency such as OHT has been detected by a dedicated sensor for detecting OHT.

[0007]

However, using a plurality of sensors to determine the material of the recording paper is costly and increases the physical configuration. Further, when the OHT is detected by the gloss sensor, the detection difference between the high gloss recording paper and the OHT is small due to the contamination of the reference white plate and the deterioration of the LED light amount. The difference could damage the device.

Further, if the determination of each medium (recording paper) is made based on the relative value while the light amount of the LED is stable, since the S / N cannot be taken, only rough determination of the medium may be made. Was. For example, it may not be possible to distinguish glossy paper having high glossiness and low glossiness. In gloss paper or the like, a difference in printing effect is caused by changing the process control depending on the degree of gloss.

Further, it knows whether the user is printed in advance what kind of recording paper, when setting the printing condition suitable from an external device or control panel on the recording paper, printing conditions of the recording paper are always trying to print Did not always fit.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a gloss detecting means which can prevent erroneous detection or erroneous judgment due to deterioration or contamination of a light source of a gloss detecting means and maintain good identification sensitivity with a simple and low-cost configuration. An object of the present invention is to provide an image forming apparatus including:

[0011]

The above object is achieved by an image forming apparatus according to the present invention. In summary, the present invention provides:
In an image forming apparatus having a detecting unit for irradiating recording paper with light and detecting a specular component of the reflected light to detect the glossiness of the recording paper surface, a correction member for performing sensitivity correction of the detecting unit; Correction means for correcting the detection level of the detection means using the correction member, and the type of recording paper is determined by the absolute value of the detection level using the saturation region of the detection means, or is corrected by the correction means. And a determining unit that determines based on the determined value, and changes a printing condition according to a determination result of the determining unit.

In the determination of the type of the recording paper by the determination means, when the output level of the detection means is larger than a specified value, the determination is made based on the absolute value of the output level. It is preferable to make the determination based on the value corrected by the correction unit.

Setting means for setting printing conditions for printing on recording paper in accordance with a result of the judgment by the judging means; storage means for storing the number of times of the printing conditions set by the setting means; Externally specifying the print condition, and changing the initial value of each parameter when the print condition is externally specified in the order of the setting number of the setting condition stored in the storage unit, in descending order. preferable.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

Embodiment 1 A color image forming apparatus, that is, a color printer according to a first embodiment of the present invention will be described with reference to FIG.

In FIG. 7, a photosensitive drum 100, a roller charger 105, and a cleaner box 113 for accumulating waste toner are integrated into a cartridge in the apparatus main assembly A, and are replaced when the number of prints reaches a specified number. And a photosensitive drum cartridge B which is detachable from the apparatus main body A.

Further, on the left side of the photosensitive drum cartridge B, a toner and a toner storage section and a developing means for performing development are integrally formed into a cartridge, which is detachably attached to the apparatus main body A which is exchanged when the consumption of the stored toner is completed. A support 12 that supports a plurality of developing cartridges Dm, Dy, Dc, and Dk so as to be rotatable about a support rotation shaft 110.
0, and the developing is performed by stopping the corresponding developing cartridge among the developing cartridges Dm, Dy, Dc, and Dk at a position facing the photosensitive drum 100 in accordance with the selected toner color.

The photosensitive drum 1 is driven in a direction indicated by an arrow at a peripheral speed of 103 mm / sec by driving means (not shown). The photosensitive drum 1 is formed by coating a photoconductor made of an organic photoconductor (OPC) on an outer peripheral surface of an aluminum cylinder having a diameter of 40 mm.
i, CdS, Se or the like.

Below the photosensitive drum cartridge B, an intermediate transfer belt (hereinafter abbreviated as "ITB") 103 having a function of transferring the image on the photosensitive drum 1 onto the belt for each color is arranged. I have.

A laser diode 104, a polygon mirror 106 rotationally driven by a high-speed motor 106a, a lens 126, and a folding mirror 12
Exposure device 107 including 5 and the like is arranged.

The photosensitive drum 1 is connected to the charging roller 105 by a negative
Vp-p to 700V DC voltage at AC frequency 700Hz
(Peak-to-peak) When a voltage on which an AC voltage of -1500 V is superimposed is applied, the voltage is uniformly charged to approximately -700 V.

When a signal according to, for example, magenta image information is input to the laser diode 104, the laser beam is irradiated on the photosensitive drum 1 through the optical path L, and the portion irradiated with the laser beam becomes approximately -100V. .

When the photosensitive drum 1 further moves in the direction of the arrow, it is visualized as a toner image by the developing cartridges Dm, Dy, Dc and Dk.

The toner image on the photosensitive drum 100 is transferred onto the ITB 103 by a voltage generated between the photosensitive drum 100 and the ITB 103 by a transfer bias applied from a high-voltage power supply (not shown) to the primary transfer roller 103a.

The above process is performed for the cyan, yellow and black colors to obtain the ITB 103
A plurality of color toner images are formed thereon.

On the other hand, the recording paper 102 stored in the cassette 101a or the multi-tray 101b is conveyed to a registration roller 122 by a paper supply roller 121, and is further fed to a transfer unit at the same timing as the toner image. The operation of the transfer roller 117 causes the ITB 103
The color image formed thereon is finally secondarily transferred to the recording paper 102.

The recording paper 102 is conveyed via a conveyor belt 111 to a conventionally known fixing device 104 for applying heat and pressure, and an unfixed image on the recording paper 102 is melted and fixed to obtain a color image.

The recording paper 102 on which fixing has been completed is discharged to a face-up (image upward) tray 108 or a face-down (image downward) tray 109.

On the other hand, the toner remaining without being transferred onto the recording paper on the photosensitive drum 100 is cleaned by a known cleaning device 113a such as a fur brush or blade means. Further, the remaining toner and the like on the ITB 103 are removed by the cleaning device 112.

Next, features of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram for discriminating the type of recording paper by a gloss sensor as a glossiness detecting means. In FIG. 1, when printing is started, the cassette 1
The recording paper 102 fed from the multi tray 01a or the multi-tray 101b determines the type of recording paper by the gloss sensor unit 115, and prints suitable for each recording paper are made.

A recording paper front end sensor 200 for detecting the front end and presence / absence of the recording paper 102 fed and conveyed is provided by:
The gloss sensor 115 is arranged upstream of the gloss sensor unit 115 in the recording paper conveyance direction, and is used as a trigger for starting the data sampling of the gloss sensor 115.

The gloss sensor unit 115 includes the light emitting circuit 2
At 01, the recording paper 102 is irradiated with light, and the specular component of the reflected light is detected by the light receiving circuit 202 to output an analog amount. The light emitting circuit 201 is mainly composed of an LED and a light receiving circuit 202.
Is composed of a phototransistor and the like.

The correction plate (correction member) 226 is a light emitting circuit 2
It is located at a position where it can receive light irradiation from the light source 01 and is used for correction due to deterioration of the LED, contamination between optical axes, and the like.

The timing generation circuit 203 controls the light emission timing of the light emitting circuit 202 based on the signal from the recording paper leading edge sensor 200, or controls the A / D conversion circuit 2
04 to generate a clock signal.
Generate a write signal to

The A / D conversion circuit 204 is a circuit for converting an analog signal from the light receiving circuit 202 of the gloss sensor unit 115 into a digital signal.

The RAM 205 is for temporarily storing gloss data of the correction plate 226.

The arithmetic circuit 206 is a circuit for calculating the average value of the gloss data of the recording paper 102 and the relative value of the gloss data of the correction plate 226 to the gloss data of the recording paper 102.

The comparison circuit 207 is for comparing the output from the arithmetic circuit 206 with the output from the ROM 208.

The ROM 208 stores a threshold value for determining the type of the recording paper 102.

The determination circuit 209 includes an A / D conversion circuit 204
And the output from the comparison circuit 207 are input.
If the data of the A / D conversion circuit 204 is valid, the data from the comparison circuit 207 is invalidated, and the A / D conversion circuit 20
If the data of No. 4 is invalid, the data from the comparison circuit 207 is adopted to make a final determination of the type of recording paper.

The external device 224 forcibly sets a parameter to the determination circuit 209 and performs a setting for performing a printing process according to the determination of the gloss sensor unit 115.

The operation panel 225 is used for setting print processing in the same manner as the external device 224.

Next, in addition to the block diagram of FIG.
The operation of the present embodiment will be described with reference to the time chart of FIG.

The recording paper 102 is conveyed and waits until it is detected by the recording paper leading edge sensor 200 (S1). When the recording paper 102 is detected, the timing generation circuit 203 activates the light emitting circuit 201 of the gloss sensor unit 115. The LED is caused to emit light (S2). LED of light emitting circuit 201
When the light is emitted, the light receiving circuit 202 receives the reflected light from the correction plate 226 as an analog signal, converts the analog signal into a digital signal by the A / D conversion circuit 204 based on the clock TrigA from the timing generation circuit 203, and sends the digital signal to the RAM 205. It is stored (S3).

Next, the clocks TrigB, TrigC, TrigD, and Trig from the timing generation circuit 203 are output.
gE captures the background gloss data of the recording paper 102,
The arithmetic circuit 206 calculates the average value Vm of the gloss data (S4). The comparison circuit 207 determines whether or not the average glossiness of the background of the recording paper 102 is equal to or greater than a specified value.
And compare them (S5). The specified value is set with reference to the saturation area of the gloss sensor.

Here, if the average value Vm of the gloss data is larger than the specified value, it is determined to be OHT (S10). If the value is smaller than the specified value, the correction data Vc stored in the RAM 205 is read out, and the arithmetic circuit 206 reads the relative value (V
m / Vc). This relative value is compared with a predetermined value A (S6). If the relative value is larger than the predetermined value A, it is determined as OHT as above (S10). On the other hand, if smaller than the predetermined value A, the relative value (Vm / Vc) is compared with the predetermined value B (S7).

Here, if the relative value is smaller than the predetermined value B, it is determined that the sheet is plain paper (S9). If it is larger than the predetermined value B, it is determined that the sheet is glossy paper (S8).

When the determination of the recording paper 102 is completed, the light emitting circuit 201 is stopped, the LED is turned off, and the process is terminated. The relationship between the predetermined values A and B is A> B.

As described above, in this embodiment, with a simple and low-cost configuration, it is possible to prevent erroneous detection or erroneous determination due to deterioration or contamination of the light source of the glossiness sensor and maintain the paper type identification sensitivity. The complexity of determining the recording paper can be eliminated.

For recording paper such as glossy paper having a large difference in printing results depending on the printing conditions, an absolute value judgment is made when the light source light quantity is high and the lightness is low when the light source light quantity is high in order to increase the discrimination sensitivity of the glossiness of the background of gloss paper. At times, it is possible to perform optimum printing by performing relative value determination and changing printing conditions according to the glossiness of gloss paper.

Embodiment 2 Next, a second embodiment of the present invention will be described with reference to FIGS.

In the first embodiment, one comparison circuit 20 is used.
However, in the present embodiment, as shown in the block diagram of FIG. 4, two comparison circuits (A, B) 207,
210 is provided.

When the gloss level of the correction plate 226 is smaller than a specified value due to deterioration of the LED during reading, the comparison circuit B 210 stores the gloss level in the RAM 205. If the gloss level of the correction plate 226 is larger than the specified value, the gloss data of the recording paper background output from the A / D conversion circuit 204 is sent to the determination circuit 209.

As described in the first embodiment, the ROM 208 stores data for storing a threshold value for determining the type of recording paper based on the relative value of the gloss data of the recording paper background to the gloss data of the correction plate 226. In this embodiment, there is provided data for storing a threshold value for changing the determination method based on the gloss data based on the correction value itself.

The details of the determination circuit 209 in this embodiment are shown in the block diagram of FIG. In FIG. 5, the judgment circuit 20
Reference numeral 9 denotes an absolute value determination threshold supply circuit 211 including a ROM or the like, and first to fourth comparison circuits 212, 213, and 21.
4, 215, first to fourth selectors 216, 217, 2
18, 219, and an OHT processing circuit 220 for setting each parameter for printing, first and second gloss paper processing circuits 221 and 222, a plain paper processing circuit 223, and an EEPROM 224 as storage means.
They are connected by a data bus.

The first to fourth comparison circuits 212 to 215
The gloss data of the background of the recording paper sent from the A / D conversion circuit 204 is compared with the threshold data from the absolute value determination threshold supply circuit 211.

The first to fourth selectors 216 to 219
It is for selecting the output from the first to fourth comparison circuits 212 to 215 and the output from the comparison circuit B210,
If the signal from the comparison circuit A 207 is true, the signal from the comparison circuit B is selected. If the signal is false, the signals from the first to fourth comparison circuits 212 to 223 are selected.

The EEPROM 224 is for storing which process has been used and how many times in the above processing circuit, and uses a nonvolatile memory which is not erased even when the power supply of the device is stopped.

The image forming control circuit 226 changes the printing procedure conditions based on the parameters of each processing circuit,
The parameters of each process are set according to the instructions of the external device and the input panel.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

The recording paper 1 is detected by the recording paper tip sensor 200.
The light emitting circuit 201 is turned on (S11). When the arrival is detected, the light emitting circuit 201 is turned on (S11).
12). Next, the gloss data Vc of the correction plate 226 is fetched (S13), and the gloss data Vm of the background of the recording paper is further obtained.
(14).

Then, the gloss data Vc of the correction plate 226 is compared with a specified value (S15).
Next, the absolute value of the gloss data is determined.

That is, the gloss data Vm of the background of the recording paper
Is compared with a predetermined value D (S16), and if it is larger than the predetermined value D, it is determined that the OHT is performed (S22). If it is smaller than the predetermined value D, it is compared with the predetermined value E (S17).
If it is smaller, it is determined to be plain paper (S21). further,
If it is larger than the predetermined value E, it is compared with the predetermined value F (1
8) If it is larger than the predetermined value F, it is determined to be glossy paper 1 (S
19) If it is smaller than the predetermined value F, it is determined that the paper is glossy paper 2 (S20), and the print setting parameters are set based on the determination of each recording paper, and the set number is stored (S26). Here, D, E, and F have a relationship of D>E> F.

On the other hand, if the gloss data Vc of the correction plate 226 is smaller than the predetermined value in S15, the correction plate 22
Gloss data V of the recording paper background with respect to the gloss data Vc of No. 6
The recording paper is determined based on the relative value of m (Vm / Vc).
That is, if the relative value (Vm / Vc) is larger than the predetermined value A, it is determined to be OHT (S23). If it is smaller than the predetermined value A, it is compared with the predetermined value B (S24). If it is smaller than the predetermined value B, it is determined that the paper is plain paper (S21). If it is larger than the predetermined value B, it is further compared with the predetermined value C. If it is larger than the predetermined value C, it is determined that the paper is glossy paper 1 (S1).
9) If it is smaller than the predetermined value C, it is determined that the gloss value is 2 (S
20) In the same manner as above, print setting parameters are set based on the determination of each recording sheet, the set number of times for each recording sheet is stored, and the process is terminated (S26). Here, the set value A,
B and C have a relationship of A>C> B.

As described above, also in this embodiment, the same effects as those of the first embodiment can be obtained, and the recording paper can be determined more precisely. Further, by changing the initial value of each parameter when designating the printing condition from the outside to the order of increasing the number by the means for storing the number of times the printing setting condition is set, the trouble of setting can be eliminated.

Embodiment 3 In the second embodiment, two types of gloss paper are used, but two or more types of gloss paper may be used. Further, when printing is started by a command for specifying gross printing based on data storing the set number of times, printing may be performed based on the setting of glossy paper having a large number of set times.

[0068]

As is apparent from the above description, according to the present invention, a correction member for correcting the sensitivity of the detection means for detecting the glossiness, and the detection means using the correction member, Correction means for correcting the detection level, and determination means for determining the type of the recording paper by using the saturation area of the detection means by an absolute value of the detection level or based on the value corrected by the correction means By changing the printing conditions according to the determination result of the determination means, a simple and low-cost configuration prevents erroneous detection or erroneous determination due to deterioration or contamination of the light source of the glossiness detection means and identifies them. The provision of the glossiness detection means capable of maintaining good sensitivity can provide the image forming apparatus.

[Brief description of the drawings]

FIG. 1 is an electric block diagram for explaining a first embodiment of the present invention.

FIG. 2 is a timing chart for explaining the first embodiment.

FIG. 3 is a flowchart for explaining the operation of the first embodiment.

FIG. 4 is an electric block diagram for explaining a second embodiment.

FIG. 5 is a detailed electric block diagram of a determination circuit according to a second embodiment.

FIG. 6 is a flowchart for explaining the operation of the second embodiment.

FIG. 7 is a configuration diagram illustrating an embodiment of an image forming apparatus in which the present invention is embodied.

[Explanation of symbols]

 115 Gloss sensor (gloss degree detection means) 206 Operation circuit 207, 210 Comparison circuit 209 Judgment circuit (judgment means) 224 EEPROM (storage means) 226 Correction plate (correction member)

Claims (3)

[Claims] 1. An image forming apparatus having a detecting means for irradiating recording paper with light and detecting a specular component of the reflected light to detect the glossiness of the surface of the recording paper, wherein the sensitivity of the detecting means is corrected. A correction member for correcting the detection level of the detection means using the correction member, and determining the type of the recording paper by the absolute value of the detection level using the saturation region of the detection means, or An image forming apparatus comprising: a determination unit that determines based on a value corrected by the correction unit, and changes a printing condition according to a determination result of the determination unit. 2. The method according to claim 1, wherein the determining unit determines the type of the recording sheet based on an absolute value of the output level when the output level of the detecting unit is higher than a specified value. 2. The image forming apparatus according to claim 1, wherein the determination is performed based on a value corrected by the correction unit. 3. A setting means for setting printing conditions for printing on recording paper in accordance with a result of the judgment by the judging means; a storage means for storing the number of times of the printing conditions set by the setting means; Means for designating printing conditions externally, and changing the initial values of the respective parameters when designating the printing conditions from the outside in the order of increasing the number of setting of the setting conditions stored in the storage means. The image forming apparatus according to claim 1, wherein: