US20010004425A1 - Color image forming apparatus - Google Patents
Color image forming apparatus Download PDFInfo
- Publication number
- US20010004425A1 US20010004425A1 US09/734,555 US73455500A US2001004425A1 US 20010004425 A1 US20010004425 A1 US 20010004425A1 US 73455500 A US73455500 A US 73455500A US 2001004425 A1 US2001004425 A1 US 2001004425A1
- Authority
- US
- United States
- Prior art keywords
- color
- positional deviation
- mark
- image
- image forming
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/46—Colour picture communication systems
- H04N1/50—Picture reproducers
- H04N1/506—Reproducing the colour component signals picture-sequentially, e.g. with reproducing heads spaced apart from one another in the subscanning direction
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
- G03G15/0142—Structure of complete machines
- G03G15/0178—Structure of complete machines using more than one reusable electrographic recording member, e.g. one for every monocolour image
- G03G15/0194—Structure of complete machines using more than one reusable electrographic recording member, e.g. one for every monocolour image primary transfer to the final recording medium
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/40—Picture signal circuits
- H04N1/407—Control or modification of tonal gradation or of extreme levels, e.g. background level
- H04N1/4076—Control or modification of tonal gradation or of extreme levels, e.g. background level dependent on references outside the picture
- H04N1/4078—Control or modification of tonal gradation or of extreme levels, e.g. background level dependent on references outside the picture using gradational references, e.g. grey-scale test pattern analysis
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G2215/00—Apparatus for electrophotographic processes
- G03G2215/01—Apparatus for electrophotographic processes for producing multicoloured copies
- G03G2215/0151—Apparatus for electrophotographic processes for producing multicoloured copies characterised by the technical problem
- G03G2215/0158—Colour registration
- G03G2215/0161—Generation of registration marks
Definitions
- the present invention relates to a color image forming apparatus.
- This color image forming apparatus may be a copying machine, a printer, and a facsimile.
- the color image forming apparatus may utilize the technology of electro-photography, electro-statics, or may utilize some other technology for forming the image on a paper.
- a tandem type of color image forming apparatus is known.
- a separate image forming unit for forming an image of a separate color for example, yellow (hereafter Y), magenta (hereafter M), cyan (hereafter C), and black (hereafter K), respectively, are lined up along a conveyer belt.
- the conveyer belt conveys the paper, on which the image is to be formed, under each image forming unit.
- the conventional color image forming apparatus is shown in detail in FIG. 2.
- a plurality of image forming units 1 Y, 1 M, 1 C, and 1 K are sequentially disposed along a conveyer belt 3 .
- the conveyer belt 3 is installed over conveyer rollers 4 and 5 so as to move in a direction shown by an arrow in FIG. 2.
- One roller of the conveyer rollers 4 and 5 also drives the conveyer belt 3 in addition to just moving the conveyer belt 3 , and the other roller just moves the conveyer belt 3 .
- a paper feeder comprises a paper feed tray 6 .
- a pile of papers is placed in the paper feed tray 6 .
- a paper 2 on the top of this pile of paper is fed to the conveyer belt 3 by not shown a paper feed roller.
- the paper 2 sticks to the conveyer belt 3 due to electrostatic adsorption.
- the conveyer belt 3 conveys the paper 2 under the Y image forming unit 1 Y.
- a transfer unit 7 Y of the Y image forming unit 1 Y forms a Y image (i.e. a yellow color image) on the paper 2 .
- the Y image forming unit 1 Y has a drum like photosensitive body 8 Y that supports an image, a charging unit 9 Y disposed in the periphery of the photosensitive body 8 Y for uniformly charging the photosensitive body 8 Y, an exposure unit 10 Y as an exposure means performing exposure for the photosensitive body 8 Y, a development unit 11 Y as a development means developing an electrostatic latent image on the photosensitive body 8 Y to form a Y toner image, and a photosensitive body cleaner 12 Y as a cleaning means cleaning the photosensitive body 8 Y.
- the photosensitive body 8 Y is rotated and driven by a not shown rotation mechanism so as to be charged uniformly by the charging unit 9 Y. Then, the photosensitive body 8 Y is exposed to a laser light 13 Y from the exposure unit 10 Y so as to form an electrostatic latent image. This electrostatic latent image on the photosensitive body 8 Y is developed by the development unit 11 Y so that the Y toner image is formed on the photosensitive body 8 Y.
- This Y toner image on the photosensitive body 8 Y is transferred onto the transfer paper 2 on the conveyer belt 3 at a position (a transfer position) where the photosensitive body 8 Y and the transfer paper 2 on the conveyer belt 3 come in contact with each other by means of the transfer unit 7 Y so that the Y toner image of only the yellow color is formed on the paper 2 .
- the photosensitive body 8 Y is prepared for the next image formation while unnecessary toner remaining on the surface is cleaned by the photosensitive body cleaner 12 Y.
- the paper 2 having the Y image formed thereon is then brought under the M image forming unit 1 M by moving the conveyer belt 3 .
- a transfer unit 7 M of the M image forming unit 1 M forms an M image (i.e. a magenta color image) over the already formed Y image.
- the paper 2 having the Y image and M image formed thereon is brought under the C image forming unit 1 C by moving the conveyer belt 3 .
- a transfer unit 7 C of the C image forming unit 1 C forms an C image (i.e. a cyan color image) over the already formed Y image and M image.
- the paper 2 having the Y image, M image, and C image formed thereon is brought under the K image forming unit 1 K by moving the conveyer belt 3 .
- a transfer unit 7 K of the K image forming unit 1 K forms an K image (i.e. a black color image) over the already formed Y image, M image, and C image.
- K image i.e. a black color image
- a full color image is formed on the paper 2 .
- the paper 2 having an image printed thereon is conveyed under a fixing unit 14 .
- the fixing unit 14 fixes the image.
- the paper 2 is discharged outside the machine.
- the M image forming unit 1 M, the C image forming unit 1 C, and the K image forming unit 1 K have drum like photosensitive bodies 8 M, 8 C, and 8 K as image support bodies, charging units 9 M, 9 C, and 9 K disposed in the peripheries of the photosensitive bodies 8 M, 8 C, and 8 K as charging means for uniformly charging the photosensitive bodies 8 M, 8 C, and 8 K, exposure units 10 M, 10 C, and 10 K as exposure means performing exposure for the photosensitive bodies 8 M, 8 C, and 8 K, development units 11 M, 11 C, and 11 K as development means developing electrostatic latent images on the photosensitive bodies 8 M, 8 C, and 8 K to make an M toner image, a C toner image, and a K toner image, and photosensitive body cleaners 121 M, 12 C, and 12 K as cleaning means cleaning the photosensitive bodies 8 M, 8 C, and 8 K, respectively, similarly to the Y image forming unit 1 Y.
- the M image forming unit 1 M, the C image forming unit 1 C, and the K image forming unit 1 K after the photosensitive bodies 8 M, 8 C, and 8 K are rotated and driven by means of rotation mechanisms which are not shown so as to be uniformly charged with electricity by the charging units 9 M, 9 C, and 9 K, respectively, they are exposed to laser lights 13 M, 13 C, and 13 K corresponding to an M image signal, a C image signal, and a K image signal by the exposure units 10 M, 10 C, and 10 K to form electrostatic latent images, respectively.
- These electrostatic latent images on the photosensitive bodies 8 M, 8 C, and 8 K are developed by the development units 11 M, 11 C, and 11 K so that the M toner image, the C toner image, and the K toner image are formed on the photosensitive bodies 8 M, 8 C, and 8 K.
- the M toner image, the C toner image, and the K toner image on the photosensitive bodies 8 M, 8 C, and 8 K are transferred onto the transfer paper 2 on the conveyer belt 3 at the positions (transfer positions) where the photosensitive bodies 8 M, 8 C, and 8 K and the transfer paper 2 on the conveyer belt 3 come in contact with each other by means of the transfer units 7 M, 7 C, and 7 K.
- the photosensitive bodies 8 M, 8 C, and 8 K are prepared for the next image formations while unnecessary toner remaining on the surfaces is cleaned by the photosensitive body cleaners 12 M, 12 C, and 12 K.
- a skew correction is performed by, for example, regulating the inclination of an optical unit or the inclination of a beam reflection mirror existing therein or the like.
- detection unit for detecting a positional deviation detection mark formed by a line in a main scanning direction and a line inclined against that line is provided.
- This detection unit is composed of a slit having an aperture which is parallel to and has the same width as the respective lines of the mark, a light source, and a light receiver.
- An image forming apparatus is disclosed in Japanese Patent No. 2642351 in which a standard part composed of a straight line extending on a non-end like conveying means in a main scanning direction and a slanting line extending in a slant manner against the straight line are formed, and a deviation amount of the slanting line in the main scanning direction is calculated through the comparison between an ideal value of the space between the standard part and the slanting line and an actually detected space, so that based on its result at least either of a main scanning write timing clock or write clock is corrected.
- An image forming apparatus is disclosed in Japanese Patent No. 2765626 in which a pattern image for measurement is formed on a non-end like conveying means, this pattern image is detected with a detection unit, a deviation between a standard pattern image for one color is and the pattern image of other colors is measured, and the timing of forming the image is adjusted based on the measured deviation in which a pattern image for measuring positional deviations for respective colors is formed on a non-end like conveying means so that this pattern image for measuring is detected by a detection unit, and a deviation amount between a pattern image for measuring one color to be a standard and a pattern image for measuring another color is calculated so that based on the deviation amount, image write timing is regulated.
- a multiple image forming apparatus is disclosed in Japanese Patent No. 2573855 in which reading of an alignment pattern for correcting a positional deviation for respective colors and reading of a density pattern for controlling the density of an image are performed by employing the same reading unit commonly.
- FIG. 3 shows the detection unit and its peripheral section described in the Japanese Patent Application Laid-Open No. HEI 10-198110.
- FIG. 4 shows side and enlarged view of the detection unit.
- the detection unit is composed of a light emitter 15 , a slit 16 , and a light receiver 17 so as to detect the positional deviation detection mark 25 formed by image forming units 21 to 24 of respective colors on a conveyer belt 20 installed over conveyer rollers 18 and 19 .
- This detection unit is disposed in both ends, respectively, in the main scanning direction, and corresponding to each detection unit, the positional deviation detection mark 25 is formed in both ends of the conveyer belt 20 , respectively.
- FIG. 5 shows the slit 16 in an enlarged manner.
- the slit 16 has an aperture 16 a with a width “a” which is parallel to a line parallel to the main scanning direction of the positional deviation detection mark 25 (hereafter, referred to as a horizontal line) and a line slanting against that horizontal line (hereafter, referred to as a vertical line) and a length “b” in order to detect the respective horizontal and vertical lines.
- a detection time difference of each line and a detection result of right/left are compared while taking black horizontal line as a standard in using the horizontal and vertical lines so that depending on the result, corrections of skew, a sub-scanning resist deviation, a main scanning resist deviation, and a main scanning magnification error are performed.
- FIG. 6 shows a timing chart of the time when the write timing of the sub-scanning direction is corrected.
- the correction resolution is supposes to be one dot.
- the write position is regulated by the timing of a synchronized detection signal.
- the write enable signal may be made active one part fast of the synchronized detection signal as shown in FIG. 6.
- FIG. 7 shows a timing chart of the time when the write timing of the main scanning direction is corrected.
- the correction resolution is supposes to be one dot.
- clocks having exactly matched phases can be obtained for respective lines by a rising edge of the synchronized detection signal.
- Writing of an image is performed, synchronizing that clock signal, and write enable signal of the main scanning direction is made, synchronizing that clock signal.
- the write enable signal may be made active one clock part fast as shown in FIG. 7.
- magnification in the main scanning direction when the magnification in the main scanning direction is deviated from the standard color as a result of the calculation using a detection result of the detection unit by a color other than the standard color, the magnification of the main scanning direction can be altered by employing a device by which the frequency of the clock can be changed by a very small step, for example, a clock generator or the like.
- same detection unit detects the alignment mark and the density pattern (image density regulation pattern).
- the alignment mark (positional deviation detection mark) 25 shown in FIG. 3 and the image density regulation pattern 26 shown in FIG. 8 are formed individually on the conveyer belt 20 by the image forming units 21 to 24 of respective colors indifferent sequences.
- a predetermined arithmetic processing is performed using the detection result of the alignment mark 25 , and according to the result, the alignment control as described above is performed.
- a predetermined arithmetic processing is performed using the detection result of the density pattern 26 for regulating an image density, and according to the result, a process condition or the like, such as a laser power, a charge bias, a development bias, or the like, is altered into an optimal value.
- the color image forming apparatus comprises a means forming and detecting the positional deviation detection mark and the image density regulation mark.
- this means forms and detects the positional deviation detection mark and the image density regulation mark in the sequence the requests were received. Therefore, the time for which the user is required to wait is shortened.
- the frequency for sampling a detection signal of the image density regulation mark and the frequency for sampling a detection signal of the positional deviation detection mark are different. Furthermore, it is preferable that the frequency for sampling the detection signal of the image density regulation mark is smaller than the frequency for sampling the detection signal of the positional deviation detection mark. Accordingly, the time for which the user is required to wait is shortened.
- a detection result of the positional deviation detection mark is discriminated.
- the discrimination is impossible, only the image density regulation for each color is performed so that the alignment for each color is not performed.
- the image density regulation for each color and the alignment for each color are performed. Accordingly, alignment can be securely performed.
- the alignment for each color is performed after the image density regulation for each color is performed. Accordingly, alignment can be securely performed.
- FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention.
- FIG. 2 is an outlined view showing one example of a color image forming apparatus.
- FIG. 3 is a perspective view showing the detection unit and its peripheral section described in the Japanese Patent Application Laid-Open No. HEI 10-198110.
- FIG. 4 is an outlined view showing the detection unit in an enlarged manner.
- FIG. 5 is a plan view showing the slit of the detection unit in an enlarged manner.
- FIG. 6 is a timing chart showing operation timing of the time of correcting the write timing of the sub-scanning direction in the image forming apparatus described in the Japanese Patent Nos. 2642351 and 2765626.
- FIG. 7 is a timing chart showing operation timing of the time of correcting the write timing of the main scanning direction in the image forming apparatus.
- FIG. 8 is a perspective view showing the detection unit and its peripheral section of the multiple image forming apparatus described in the Japanese Patent No. 2573855.
- FIG. 9 is a plan view showing a state wherein the image density regulation mark and the alignment mark are formed on the conveyer belt in the embodiment according to the present invention.
- FIG. 10 is a plan view showing another example in which the image density regulation mark and the alignment mark are formed on the conveyer belt in the embodiment according to the present invention.
- FIG. 11 is a timing chart showing timing of data sampling in the case of forming and detecting the image density regulation mark and the alignment detection mark in the embodiment according to the present invention.
- FIG. 12 is a view for explaining the embodiment according to the present invention.
- FIG. 13 is a flowchart showing a processing flow of the time of an alignment and an image density regulation in the embodiment according to the present invention.
- FIG. 2 One preferred embodiment of the present invention is explained below with reference to the attached drawings. It is assumed that the present invention is applied to the conventional color image forming apparatus shown in FIG. 2. Further, it is assumed that a main CPU performs the requests for alignment and a request for image density regulation. The main CPU monitors the number of printed papers, temperature of the surrounding, temperatures of the respective units of the color image forming apparatus, and the like, and performs the request for alignment and the request for image density regulation based on result of this monitoring. There is a possibility that the main CPU does not output the requests for alignment and the request for image density regulation at one time or at substantially one time.
- the main CPU outputs the requests for alignment and the request for image density regulation at one time or at substantially one time, then the alignment mark and the image density regulation mark are formed in the same sequence.
- the image density regulation mark 26 and the alignment mark 25 are sequentially arranged in the conveying direction.
- the image density regulation mark 26 is formed upstream from the alignment mark 25 on the conveyer belt 3
- the alignment mark 25 is formed downstream from the image density regulation mark 26 on the conveyer belt 3 .
- the order of the image density regulation mark 26 and the alignment mark 25 is not limited to this.
- the alignment mark 25 is formed upstream from the image density regulation mark 26 on the conveyer belt 3 .
- the image density regulation mark 26 is formed downstream from the image density regulation mark 26 on the conveyer belt 3 as shown in FIG. 10.
- the image density regulation mark 26 and the alignment mark 25 are formed alternately on the conveyer belt 3 .
- FIG. 11 shows timing of data sampling in the case of forming and detecting the positional deviation detection mark 25 and image density regulation mark 26 as shown in FIG. 9. Since the image density regulation mark 26 is formed upstream from the positional deviation detection mark 25 on the conveyer belt 3 , first, a sampling enable signal/PROSMP_EN making sampling of a detection signal from the image density regulation mark 26 effective becomes active, and then a sampling enable signal REGSMP_EN making sampling of a detection signal from the positional deviation detection mark 25 formed downstream from the image density regulation mark 26 on the conveyer belt 3 effective becomes active.
- the frequency of a data sampling clock signal SMP_CLK is set to 30 kHz during the period in which PROSMP_EN becomes active and to 90 kHz during the period in which REGSMP_EN becomes active. This is because high resolution is required in the detection from the image density regulation mark 25 .
- the frequency of SMP_CLK is altered for each sampling enable signal as described above to minimize data number to be handled as much as possible so that the time taken for calculation process is shortened, whereby a waiting time of a user can be shortened.
- FIG. 1 shows the configuration of the present embodiment. As mentioned above, this configuration is employed in the color image forming apparatus shown in FIG. 2.
- the detection unit according to the present invention comprises the light emitter 15 , the slit 16 , and the light receiver 17 .
- This detection unit detects the positional deviation detection mark 25 and image density regulation mark 26 formed on the conveyer belt 20 by the image forming units 1 Y, 1 M, 1 C, and 1 K for the respective colors.
- the detection unit is disposed between the image forming unit 1 K and the fixing unit 14 .
- the light emitter 15 is disposed in an outer side of the conveyer belt 3
- the slit 16 and the light receiver 17 are disposed in an inner side of the conveyer belt 3 .
- the light from the light emitter 15 is received at the light receiver 17 through the transparent conveyer belt 3 and the aperture 16 a of the slit 16 .
- the signal obtained from the light receiver 17 is amplified by an amplifier 27 and supplied to a filter 28 .
- the filter allows only a signal component that corresponds to the detected mark to passed through to an A/D converter 29 .
- the A/D converter 29 samples the analog signal and obtains a digital data.
- FIFO memory 31 stores the digital data.
- a sampling control section 30 controls sampling of the data by the A/D converter 29 .
- Two sets of such a detection unit are provided on each side of the conveyer belt. Both the sets of the detection unit have the same configuration.
- a digital data is stored in the FIFO memory 31 .
- This digital data is loaded into a main CPU 34 and a RAM 35 via an I/O port 32 through a data bus 33 .
- the main CPU 34 performs arithmetic processing for calculating various kinds of positional deviation amounts and optimal process conditions. Therefore, the main CPU 34 works as an arithmetic means for calculating data from the positional deviation detection mark 25 and image density regulation mark 26 as well.
- a ROM 36 stores various kinds of programs and data tables and the like, such as a program for calculating various kinds of positional deviation amounts and optimal process conditions down.
- the main CPU 34 appoints the address of the ROM 36 , the address of the RAM 35 , and various types of input-output devices through an address bus 37 .
- the main CPU 34 monitors the detection signal from the light receiver 17 by appropriate timing and controls a light emission amount of the light emitter 15 via an emission amount control section 38 so as to securely detect degradations or the like of the conveyer belt 3 and the light emitter 15 even when the degradation occurs so that the level of the light receiving signal from the light receiver 17 is constant at all times.
- the main CPU 34 alters a main scanning direction resist, a sub-scanning direction resist, and a magnification error by setting for a write control substrate 39 as a write control means controlling writing by the exposure units 10 Y, 10 M, 10 C, and 10 K based on various correction amounts sought in the arithmetic processing of the data from the positional deviation detection mark 25 on the occasion of an alignment so as to correct a positional deviation of another color against the standard color.
- the write control substrate 39 is provided with a device which can set an output frequency very finely, for example, a clock generator utilizing a VCO (Voltage Controlled Oscillator) or the like, for each color including the standard color and employs its output as an image clock.
- VCO Voltage Controlled Oscillator
- the main CPU 34 sets process conditions of the laser powers of the exposure units 10 Y, 10 M, 10 C, and 10 K, charge biases of the charging units 9 Y, 9 M, 9 C, and 9 K, development biases of the development units 11 Y, 11 M, 11 C, and 11 K, and the like for the write control substrate 39 , a charge bias power supply 40 applying charge biases to the charging units 9 Y, 9 M, 9 C, and 9 K, a development bias power supply 41 applying development biases to the development units 11 Y, 11 M, 11 C, and 11 K, and the like, respectively, based on various correction amounts sought in the arithmetic processing of the data from the image density regulation mark 26 on the occasion of an image density regulation so as to control the process conditions.
- the main CPU 34 constitutes a control means for controlling the main scanning direction resist, the sub-scanning direction resist, the magnification, and the process condition.
- FIG. 13 shows a processing flow of the time of the alignment and the image density regulation in the present embodiment.
- the main CPU 34 initializes (zero substitutes) a flag REG_FLG showing that the alignment is required and a flag PRO_FLG showing that the image density regulation is required (step S 1 ). Then, the main CPU 34 determines whether or not the alignment is required (step S 2 ) and sets a flag REG_FLG to 1 (one) (step S 3 ) when the alignment is required to proceed to a step S 4 . The main CPU 34 proceeds to the step S 4 when the alignment is not required.
- the main CPU 34 determines whether or not the image density regulation is required (step S 4 ) and sets a flag PRO_FLG to 1 (one) (step S 5 ) when the image density regulation is required to proceed to a step S 6 .
- the main CPU 34 proceeds to the step S 6 when the image density regulation is not required.
- the main CPU 34 determines whether or not the flag REG_FLG is 1 and the flag PRO_FLG is 1 (step S 6 ) and controls each section of the present embodiment when REG_FLG is 1 and PRO_FLG is 1 to form both marks 25 , 26 in the same sequence (step S 7 ).
- Both the positional deviation detection mark 25 and image density regulation mark 26 are detected by the detection unit, and the detection signal from this detection unit is stored in the FIFO memory 31 via the amplifier 27 , the filter 28 , and the A/D converter 29 . After the whole detection for the marks is completed, the data stored in the FIFO memory 31 are loaded into the main CPU 34 and the RAM 35 via the I/O port 32 by the data bus 33 (step S 8 ).
- the main CPU 34 determines whether or not all alignment marks 25 can be discriminated through the data from the alignment marks 25 (step S 9 ).
- the main CPU 34 performs arithmetic processing of the data from the alignment marks 25 and setting for the write control substrate 39 described above (step S 10 ) and performs arithmetic processing of the data from the image density regulation mark 26 and setting for the write control substrate 39 , the charge bias power supply 40 , the development bias power supply 41 , and the like described above (step S 11 ) to return.
- the main CPU 34 proceeds to step S 11 when all the alignment marks 25 cannot be discriminated.
- the main CPU 34 determines whether the flag REG_FLG is equal to 1 and whether the flag PRO_FLG is equal to 0 (zero) (step S 12 ).
- the main CPU 34 controls each section of the present embodiment to form only the alignment mark 25 (step S 13 ).
- the alignment mark 25 is detected by the detection unit, and the detection signal from this detection unit is stored in the FIFO memory 31 via the amplifier 27 , the filter 28 , and the A/D converter 29 .
- the digital data stored in the FIFO memory 31 are loaded into the main CPU 34 and the RAM 35 through the I/O port 32 by the data bus 33 (step S 14 ) after the whole detection of the alignment mark 25 is completed.
- the main CPU 34 then performs the arithmetic processing of the data from the alignment mark 25 and the setting for the write control substrate 39 as described above (step S 15 ) to return.
- the main CPU 34 determines whether the flag REG_FLG is equal to 0 and whether the flag PRO_FLG is equal to 1.
- the main CPU 34 controls each section of the present embodiment to form only the image density regulation mark 26 (step S 17 )
- the image density regulation mark 26 is detected by the detection unit, and the detection signal from this detection unit is stored in the FIFO memory 31 via the amplifier 27 , the filter 28 , and the A/D converter 29 .
- the digital data stored in the FIFO memory 31 are loaded into the main CPU 34 and the RAM 35 through the I/O port 32 by the data bus 33 (step S 18 ) after the whole detection of the image density regulation mark 26 is completed.
- the main CPU 34 then performs the arithmetic processing of the data from the image density regulation mark 26 and the setting for the write control substrate 39 , the charge bias power supply 40 , the development bias power supply 41 , and the like as described above (step S 19 ) to return.
- the flag REG_FLG is not equal to 0 and the flag PRO_FLG is not equal to 1
- the main CPU 34 returns.
- the color image forming apparatus transferring in superimposing one after another images of the plurality of colors formed in the plurality of image forming units 1 Y, 1 M, 1 C, and 1 K forming the plural colors of images, respectively, on the transfer paper 2 as a recording medium on the conveyer belt 3 as a conveyer body to obtain a color image on the recording medium, forming a positional deviation detection mark 25 on the conveyer body 3 according to the alignment requirement to detect the positional deviation detection mark 25 , performing an alignment for each color by calculating a positional deviation amount of a color against a standard color according to its detection result and correcting a positional deviation of the color against the standard color, forming the image density regulation mark 26 on the conveyer body 2 according to the image density control requirement to detect the image density regulation mark 26 , and regulating image density for each color according to its detection result, since the color image forming apparatus comprises the image forming units 1 Y, 1 M, 1 C, and 1 K, the detection unit, and the main CPU 34 as
- the frequency for sampling the detection signal of the image density regulation mark 26 and the frequency for sampling the detection signal of the positional deviation detection mark 25 are made different.
- the frequency for sampling the detection signal of the image density regulation mark 26 is less than the frequency for sampling the detection signal of the positional deviation detection mark 25 .
- the alignment for each color is not performed.
- the image density regulation for each color and the alignment for each color are performed.
- the alignment can be securely performed.
- the alignment for each color is performed after the image density regulation for each color is performed.
- a clean positional deviation detection mark can be formed after the image density is regulated, whereby the alignment can be securely performed.
- the present invention is not limited to the embodiment described above and.
- this invention can be applied to a color image forming apparatus transferring in superimposing one after another images of a plurality of colors formed in a plurality of image forming units on an intermediate transfer body to transfer the images on a recording medium by a transfer means to fix them by a fixing unit, forming a positional deviation detection mark on the intermediate transfer body to detect the positional deviation detection mark, performing an alignment for each color by calculating a positional deviation amount of a color against a standard color according to its detection result and correcting a positional deviation of the color against the standard color, forming an image density regulation mark on the intermediate transfer body according to an image density control requirement to detect the image density regulation mark, and regulating image density for each color according to its detection result.
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Control Or Security For Electrophotography (AREA)
- Color Electrophotography (AREA)
Abstract
Description
- The present invention relates to a color image forming apparatus. This color image forming apparatus may be a copying machine, a printer, and a facsimile. The color image forming apparatus may utilize the technology of electro-photography, electro-statics, or may utilize some other technology for forming the image on a paper.
- Conventionally, a tandem type of color image forming apparatus is known. In this conventional color image forming apparatus, a separate image forming unit for forming an image of a separate color, for example, yellow (hereafter Y), magenta (hereafter M), cyan (hereafter C), and black (hereafter K), respectively, are lined up along a conveyer belt. The conveyer belt conveys the paper, on which the image is to be formed, under each image forming unit. The conventional color image forming apparatus is shown in detail in FIG. 2.
- As shown in FIG. 2, in the conventional color image forming apparatus, a plurality of
image forming units 1Y, 1M, 1C, and 1K are sequentially disposed along aconveyer belt 3. Theconveyer belt 3 is installed overconveyer rollers 4 and 5 so as to move in a direction shown by an arrow in FIG. 2. One roller of theconveyer rollers 4 and 5 also drives theconveyer belt 3 in addition to just moving theconveyer belt 3, and the other roller just moves theconveyer belt 3. A paper feeder comprises apaper feed tray 6. A pile of papers is placed in thepaper feed tray 6. Apaper 2 on the top of this pile of paper is fed to theconveyer belt 3 by not shown a paper feed roller. Thepaper 2 sticks to theconveyer belt 3 due to electrostatic adsorption. - The
conveyer belt 3 conveys thepaper 2 under the Yimage forming unit 1Y. At this position, a transfer unit 7Y of the Yimage forming unit 1Y forms a Y image (i.e. a yellow color image) on thepaper 2. The Yimage forming unit 1Y has a drum likephotosensitive body 8Y that supports an image, a charging unit 9Y disposed in the periphery of thephotosensitive body 8Y for uniformly charging thephotosensitive body 8Y, anexposure unit 10Y as an exposure means performing exposure for thephotosensitive body 8Y, a development unit 11Y as a development means developing an electrostatic latent image on thephotosensitive body 8Y to form a Y toner image, and aphotosensitive body cleaner 12Y as a cleaning means cleaning thephotosensitive body 8Y. - The
photosensitive body 8Y is rotated and driven by a not shown rotation mechanism so as to be charged uniformly by the charging unit 9Y. Then, thephotosensitive body 8Y is exposed to a laser light 13Y from theexposure unit 10Y so as to form an electrostatic latent image. This electrostatic latent image on thephotosensitive body 8Y is developed by the development unit 11Y so that the Y toner image is formed on thephotosensitive body 8Y. This Y toner image on thephotosensitive body 8Y is transferred onto thetransfer paper 2 on theconveyer belt 3 at a position (a transfer position) where thephotosensitive body 8Y and thetransfer paper 2 on theconveyer belt 3 come in contact with each other by means of the transfer unit 7Y so that the Y toner image of only the yellow color is formed on thepaper 2. After the transfer of the Y toner image is completed, thephotosensitive body 8Y is prepared for the next image formation while unnecessary toner remaining on the surface is cleaned by thephotosensitive body cleaner 12Y. - The
paper 2 having the Y image formed thereon is then brought under the M image forming unit 1M by moving theconveyer belt 3. At this position, atransfer unit 7M of the M image forming unit 1M forms an M image (i.e. a magenta color image) over the already formed Y image. Then, thepaper 2 having the Y image and M image formed thereon is brought under the C image forming unit 1C by moving theconveyer belt 3. At this position, a transfer unit 7C of the C image forming unit 1C forms an C image (i.e. a cyan color image) over the already formed Y image and M image. Then, thepaper 2 having the Y image, M image, and C image formed thereon is brought under the K image forming unit 1K by moving theconveyer belt 3. At this position, atransfer unit 7K of the K image forming unit 1K forms an K image (i.e. a black color image) over the already formed Y image, M image, and C image. Thus, a full color image is formed on thepaper 2. Then, thepaper 2 having an image printed thereon is conveyed under afixing unit 14. Thefixing unit 14 fixes the image. Finally, thepaper 2 is discharged outside the machine. - The M image forming unit1M, the C image forming unit 1C, and the K image forming unit 1K have drum like
photosensitive bodies charging units photosensitive bodies photosensitive bodies exposure units photosensitive bodies photosensitive bodies photosensitive body cleaners 121M, 12C, and 12K as cleaning means cleaning thephotosensitive bodies image forming unit 1Y. - In the M image forming unit1M, the C image forming unit 1C, and the K image forming unit 1K, after the
photosensitive bodies charging units laser lights exposure units photosensitive bodies photosensitive bodies photosensitive bodies transfer paper 2 on theconveyer belt 3 at the positions (transfer positions) where thephotosensitive bodies transfer paper 2 on theconveyer belt 3 come in contact with each other by means of thetransfer units photosensitive bodies photosensitive body cleaners - In the conventional color image forming apparatus it is necessary that the different color images are formed at exact positions. For example, if the positions of the image forming units is not aligned, then the image will get distorted. Therefore, a technique for an alignment between respective colors is a significant issue from the constitutional standpoint. The factors that cause static positional deviation of respective colors mainly include skew, positional deviation of the resist in the sub-scanning direction and main scanning direction, and error in magnification in the main scanning direction.
- A skew correction is performed by, for example, regulating the inclination of an optical unit or the inclination of a beam reflection mirror existing therein or the like.
- In the color image forming method described in Japanese Patent Application Laid-Open No. HEI 10-198110, detection unit for detecting a positional deviation detection mark formed by a line in a main scanning direction and a line inclined against that line is provided. This detection unit is composed of a slit having an aperture which is parallel to and has the same width as the respective lines of the mark, a light source, and a light receiver.
- An image forming apparatus is disclosed in Japanese Patent No. 2642351 in which a standard part composed of a straight line extending on a non-end like conveying means in a main scanning direction and a slanting line extending in a slant manner against the straight line are formed, and a deviation amount of the slanting line in the main scanning direction is calculated through the comparison between an ideal value of the space between the standard part and the slanting line and an actually detected space, so that based on its result at least either of a main scanning write timing clock or write clock is corrected.
- An image forming apparatus is disclosed in Japanese Patent No. 2765626 in which a pattern image for measurement is formed on a non-end like conveying means, this pattern image is detected with a detection unit, a deviation between a standard pattern image for one color is and the pattern image of other colors is measured, and the timing of forming the image is adjusted based on the measured deviation in which a pattern image for measuring positional deviations for respective colors is formed on a non-end like conveying means so that this pattern image for measuring is detected by a detection unit, and a deviation amount between a pattern image for measuring one color to be a standard and a pattern image for measuring another color is calculated so that based on the deviation amount, image write timing is regulated.
- A multiple image forming apparatus is disclosed in Japanese Patent No. 2573855 in which reading of an alignment pattern for correcting a positional deviation for respective colors and reading of a density pattern for controlling the density of an image are performed by employing the same reading unit commonly.
- FIG. 3 shows the detection unit and its peripheral section described in the Japanese Patent Application Laid-Open No. HEI 10-198110. FIG. 4 shows side and enlarged view of the detection unit. The detection unit is composed of a
light emitter 15, aslit 16, and alight receiver 17 so as to detect the positionaldeviation detection mark 25 formed byimage forming units 21 to 24 of respective colors on aconveyer belt 20 installed overconveyer rollers deviation detection mark 25 is formed in both ends of theconveyer belt 20, respectively. - FIG. 5 shows the
slit 16 in an enlarged manner. Theslit 16 has an aperture 16 a with a width “a” which is parallel to a line parallel to the main scanning direction of the positional deviation detection mark 25 (hereafter, referred to as a horizontal line) and a line slanting against that horizontal line (hereafter, referred to as a vertical line) and a length “b” in order to detect the respective horizontal and vertical lines. A detection time difference of each line and a detection result of right/left are compared while taking black horizontal line as a standard in using the horizontal and vertical lines so that depending on the result, corrections of skew, a sub-scanning resist deviation, a main scanning resist deviation, and a main scanning magnification error are performed. - In the image forming apparatuses described in the Japanese Patent Nos. 2642351 and 2765626, a correction based on various kinds of deviation amounts calculated through detection results of the detection unit is performed as follows, similarly to the color image forming method described in the Japanese Patent Application Laid-Open No. HEI 10-198110.
- FIG. 6 shows a timing chart of the time when the write timing of the sub-scanning direction is corrected. In this case, the correction resolution is supposes to be one dot. With respect to an image region signal (write enable signal) of the sub-scanning direction, the write position is regulated by the timing of a synchronized detection signal. Now, when it is wanted that the write position is advanced one dot depending on the result of the calculation using a detection result of the detection unit, the write enable signal may be made active one part fast of the synchronized detection signal as shown in FIG. 6.
- FIG. 7 shows a timing chart of the time when the write timing of the main scanning direction is corrected. In this case, the correction resolution is supposes to be one dot. With respect to the image write clock, clocks having exactly matched phases can be obtained for respective lines by a rising edge of the synchronized detection signal. Writing of an image is performed, synchronizing that clock signal, and write enable signal of the main scanning direction is made, synchronizing that clock signal. Now, when it is wanted that the write position is advanced one dot depending on the result of the calculation using a detection result of the detection unit, the write enable signal may be made active one clock part fast as shown in FIG. 7.
- Further, when the magnification in the main scanning direction is deviated from the standard color as a result of the calculation using a detection result of the detection unit by a color other than the standard color, the magnification of the main scanning direction can be altered by employing a device by which the frequency of the clock can be changed by a very small step, for example, a clock generator or the like.
- In the multiple image forming apparatus described in the Japanese Patent No. 2573855, same detection unit detects the alignment mark and the density pattern (image density regulation pattern). In this case, the alignment mark (positional deviation detection mark)25 shown in FIG. 3 and the image
density regulation pattern 26 shown in FIG. 8 are formed individually on theconveyer belt 20 by theimage forming units 21 to 24 of respective colors indifferent sequences. - A predetermined arithmetic processing is performed using the detection result of the
alignment mark 25, and according to the result, the alignment control as described above is performed. Similarly, a predetermined arithmetic processing is performed using the detection result of thedensity pattern 26 for regulating an image density, and according to the result, a process condition or the like, such as a laser power, a charge bias, a development bias, or the like, is altered into an optimal value. - In the multiple image forming apparatus described in the Japanese Patent No. 2573855, since the alignment operation in which the detection result of the
alignment mark 25 is calculated and in accordance with the result the alignment control is performed and the image density regulation operation in which the detection result of thedensity pattern 26 is calculated and in accordance with the result a process condition or the like is altered are executed in different sequences, useless time is taken so that a waiting time of a user becomes long. - It is the first object of the present invention to provide a color image forming apparatus by which a waiting time of a user can be shortened.
- It is the second object of the present invention to provide a color image forming apparatus in which a running cost can be reduced.
- It is the third object of the present invention to provide a color image forming apparatus by which a waiting time of a user can be shortened.
- It is the fourth object of the present invention to provide a color image forming apparatus by which an alignment can be securely performed.
- It is the fifth object of the present invention to provide a color image forming apparatus by which an alignment can be securely performed.
- The color image forming apparatus according to one aspect of the invention comprises a means forming and detecting the positional deviation detection mark and the image density regulation mark. When requests for image density control and alignment are almost simultaneously received, this means forms and detects the positional deviation detection mark and the image density regulation mark in the sequence the requests were received. Therefore, the time for which the user is required to wait is shortened.
- Further, it is preferable that if only a request for image density control is received only the image density regulation mark is detected and if only a request for alignment is received only the positional deviation detection mark is detected. Accordingly, the running cost can be reduced.
- Further, it is preferable that the frequency for sampling a detection signal of the image density regulation mark and the frequency for sampling a detection signal of the positional deviation detection mark are different. Furthermore, it is preferable that the frequency for sampling the detection signal of the image density regulation mark is smaller than the frequency for sampling the detection signal of the positional deviation detection mark. Accordingly, the time for which the user is required to wait is shortened.
- Further, it is preferable that a detection result of the positional deviation detection mark is discriminated. When the discrimination is impossible, only the image density regulation for each color is performed so that the alignment for each color is not performed. One the other hand, when the discrimination is possible, the image density regulation for each color and the alignment for each color are performed. Accordingly, alignment can be securely performed.
- Further, it is preferable that, when the discrimination is impossible, the alignment for each color is performed after the image density regulation for each color is performed. Accordingly, alignment can be securely performed.
- Other objects and features of this invention will become apparent from the following description with reference to the accompanying drawings.
- FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention.
- FIG. 2 is an outlined view showing one example of a color image forming apparatus.
- FIG. 3 is a perspective view showing the detection unit and its peripheral section described in the Japanese Patent Application Laid-Open No. HEI 10-198110.
- FIG. 4 is an outlined view showing the detection unit in an enlarged manner.
- FIG. 5 is a plan view showing the slit of the detection unit in an enlarged manner.
- FIG. 6 is a timing chart showing operation timing of the time of correcting the write timing of the sub-scanning direction in the image forming apparatus described in the Japanese Patent Nos. 2642351 and 2765626.
- FIG. 7 is a timing chart showing operation timing of the time of correcting the write timing of the main scanning direction in the image forming apparatus.
- FIG. 8 is a perspective view showing the detection unit and its peripheral section of the multiple image forming apparatus described in the Japanese Patent No. 2573855.
- FIG. 9 is a plan view showing a state wherein the image density regulation mark and the alignment mark are formed on the conveyer belt in the embodiment according to the present invention.
- FIG. 10 is a plan view showing another example in which the image density regulation mark and the alignment mark are formed on the conveyer belt in the embodiment according to the present invention.
- FIG. 11 is a timing chart showing timing of data sampling in the case of forming and detecting the image density regulation mark and the alignment detection mark in the embodiment according to the present invention.
- FIG. 12 is a view for explaining the embodiment according to the present invention.
- FIG. 13 is a flowchart showing a processing flow of the time of an alignment and an image density regulation in the embodiment according to the present invention.
- One preferred embodiment of the present invention is explained below with reference to the attached drawings. It is assumed that the present invention is applied to the conventional color image forming apparatus shown in FIG. 2. Further, it is assumed that a main CPU performs the requests for alignment and a request for image density regulation. The main CPU monitors the number of printed papers, temperature of the surrounding, temperatures of the respective units of the color image forming apparatus, and the like, and performs the request for alignment and the request for image density regulation based on result of this monitoring. There is a possibility that the main CPU does not output the requests for alignment and the request for image density regulation at one time or at substantially one time. When the main CPU performs only the request for alignment at one time, then an alignment operation of calculation of a detection result of an alignment mark (positional deviation detection mark) and performing alignment control according to the result is performed. On the other hand, when the main CPU performs only the request for image density regulation at one time, then an image density regulation operation of calculation of a detection result of an image density regulation mark and altering a process condition and the like according to the result is performed.
- If the main CPU outputs the requests for alignment and the request for image density regulation at one time or at substantially one time, then the alignment mark and the image density regulation mark are formed in the same sequence. As shown in FIG. 9, on both ends of the conveyer belt3 (inside an image region or a region where the
paper 2 does not lie) the imagedensity regulation mark 26 and thealignment mark 25 are sequentially arranged in the conveying direction. The imagedensity regulation mark 26 is formed upstream from thealignment mark 25 on theconveyer belt 3, and thealignment mark 25 is formed downstream from the imagedensity regulation mark 26 on theconveyer belt 3. - The order of the image
density regulation mark 26 and thealignment mark 25 is not limited to this. For example, it is allowable that thealignment mark 25 is formed upstream from the imagedensity regulation mark 26 on theconveyer belt 3. Further, it is allowable that the imagedensity regulation mark 26 is formed downstream from the imagedensity regulation mark 26 on theconveyer belt 3 as shown in FIG. 10. Further, it is possible that the imagedensity regulation mark 26 and thealignment mark 25 are formed alternately on theconveyer belt 3. - FIG. 11 shows timing of data sampling in the case of forming and detecting the positional
deviation detection mark 25 and imagedensity regulation mark 26 as shown in FIG. 9. Since the imagedensity regulation mark 26 is formed upstream from the positionaldeviation detection mark 25 on theconveyer belt 3, first, a sampling enable signal/PROSMP_EN making sampling of a detection signal from the imagedensity regulation mark 26 effective becomes active, and then a sampling enable signal REGSMP_EN making sampling of a detection signal from the positionaldeviation detection mark 25 formed downstream from the imagedensity regulation mark 26 on theconveyer belt 3 effective becomes active. - The frequency of a data sampling clock signal SMP_CLK is set to 30 kHz during the period in which PROSMP_EN becomes active and to 90 kHz during the period in which REGSMP_EN becomes active. This is because high resolution is required in the detection from the image
density regulation mark 25. The frequency of SMP_CLK is altered for each sampling enable signal as described above to minimize data number to be handled as much as possible so that the time taken for calculation process is shortened, whereby a waiting time of a user can be shortened. - There may be a case in which discrimination of the line of the positional
deviation detection mark 25 becomes impossible during the formation and detection of the positionaldeviation detection mark 25 and imagedensity regulation mark 26 in the same sequence. This case can occur when the image density is considerably low. For example, as shown in FIG. 12, when the centers of the lines of the respective the positionaldeviation detection mark 25 and imagedensity regulation mark 26 are sought from intersections P1, P2, P3, P4, . . . between the detection signals of the positionaldeviation detection mark 25 and a predetermined threshold level Vsh the line of cyan C cannot be recognized. - That is, although the line center Pc1 of the mark of black K is sought from the intersections P1 and P2, since the line center of the next mark becomes the line center Pc2 of the mark of magenta, Pc2 is sought from the intersections P3 and P4. For this type of line recognition error, after all line centers are sought, discrimination is possible depending on whether or not its number is desired number and the like.
- If this type of line recognition error occurs, only the detection result of the image
density regulation mark 26 is utilized and is given a predetermined arithmetic process, and according to the arithmetic process result, a process condition or the like, such as a laser power, a charge bias, a development bias, or the like, is altered into an optimal value. Then, the formation and detection of the imagedensity regulation mark 25 are performed again so that the formation and detection of a clean imagedensity regulation mark 25 is performed, thereby eliminating a situation in which a detection level of the imagedensity regulation mark 26 becomes Vsh or less, whereby the alignment can be performed securely. - FIG. 1 shows the configuration of the present embodiment. As mentioned above, this configuration is employed in the color image forming apparatus shown in FIG. 2. The detection unit according to the present invention comprises the
light emitter 15, theslit 16, and thelight receiver 17. This detection unit detects the positionaldeviation detection mark 25 and imagedensity regulation mark 26 formed on theconveyer belt 20 by theimage forming units 1Y, 1M, 1C, and 1K for the respective colors. The detection unit is disposed between the image forming unit 1K and the fixingunit 14. Thelight emitter 15 is disposed in an outer side of theconveyer belt 3, and theslit 16 and thelight receiver 17 are disposed in an inner side of theconveyer belt 3. The light from thelight emitter 15 is received at thelight receiver 17 through thetransparent conveyer belt 3 and the aperture 16 a of theslit 16. - The signal obtained from the
light receiver 17 is amplified by anamplifier 27 and supplied to afilter 28. The filter allows only a signal component that corresponds to the detected mark to passed through to an A/D converter 29. The A/D converter 29 samples the analog signal and obtains a digital data.FIFO memory 31 stores the digital data. Asampling control section 30 controls sampling of the data by the A/D converter 29. Two sets of such a detection unit are provided on each side of the conveyer belt. Both the sets of the detection unit have the same configuration. - Thus, when the positional
deviation detection mark 25 and imagedensity regulation mark 26 is detected, a digital data is stored in theFIFO memory 31. This digital data is loaded into amain CPU 34 and aRAM 35 via an I/O port 32 through adata bus 33. Thereafter, themain CPU 34 performs arithmetic processing for calculating various kinds of positional deviation amounts and optimal process conditions. Therefore, themain CPU 34 works as an arithmetic means for calculating data from the positionaldeviation detection mark 25 and imagedensity regulation mark 26 as well. - A
ROM 36 stores various kinds of programs and data tables and the like, such as a program for calculating various kinds of positional deviation amounts and optimal process conditions down. Themain CPU 34 appoints the address of theROM 36, the address of theRAM 35, and various types of input-output devices through anaddress bus 37. Themain CPU 34 monitors the detection signal from thelight receiver 17 by appropriate timing and controls a light emission amount of thelight emitter 15 via an emissionamount control section 38 so as to securely detect degradations or the like of theconveyer belt 3 and thelight emitter 15 even when the degradation occurs so that the level of the light receiving signal from thelight receiver 17 is constant at all times. - The main CPU34 alters a main scanning direction resist, a sub-scanning direction resist, and a magnification error by setting for a
write control substrate 39 as a write control means controlling writing by theexposure units deviation detection mark 25 on the occasion of an alignment so as to correct a positional deviation of another color against the standard color. Thewrite control substrate 39 is provided with a device which can set an output frequency very finely, for example, a clock generator utilizing a VCO (Voltage Controlled Oscillator) or the like, for each color including the standard color and employs its output as an image clock. - The
main CPU 34 sets process conditions of the laser powers of theexposure units units write control substrate 39, a charge bias power supply 40 applying charge biases to the chargingunits density regulation mark 26 on the occasion of an image density regulation so as to control the process conditions. Thus, themain CPU 34 constitutes a control means for controlling the main scanning direction resist, the sub-scanning direction resist, the magnification, and the process condition. - FIG. 13 shows a processing flow of the time of the alignment and the image density regulation in the present embodiment. The
main CPU 34 initializes (zero substitutes) a flag REG_FLG showing that the alignment is required and a flag PRO_FLG showing that the image density regulation is required (step S1). Then, themain CPU 34 determines whether or not the alignment is required (step S2) and sets a flag REG_FLG to 1 (one) (step S3) when the alignment is required to proceed to a step S4. Themain CPU 34 proceeds to the step S4 when the alignment is not required. - The
main CPU 34 then determines whether or not the image density regulation is required (step S4) and sets a flag PRO_FLG to 1 (one) (step S5) when the image density regulation is required to proceed to a step S6. Themain CPU 34 proceeds to the step S6 when the image density regulation is not required. Themain CPU 34 then determines whether or not the flag REG_FLG is 1 and the flag PRO_FLG is 1 (step S6) and controls each section of the present embodiment when REG_FLG is 1 and PRO_FLG is 1 to form bothmarks deviation detection mark 25 and imagedensity regulation mark 26 are detected by the detection unit, and the detection signal from this detection unit is stored in theFIFO memory 31 via theamplifier 27, thefilter 28, and the A/D converter 29. After the whole detection for the marks is completed, the data stored in theFIFO memory 31 are loaded into themain CPU 34 and theRAM 35 via the I/O port 32 by the data bus 33 (step S8). - Next, the
main CPU 34 determines whether or not all alignment marks 25 can be discriminated through the data from the alignment marks 25 (step S9). When all the alignment marks 25 can be discriminated, themain CPU 34 performs arithmetic processing of the data from the alignment marks 25 and setting for thewrite control substrate 39 described above (step S10) and performs arithmetic processing of the data from the imagedensity regulation mark 26 and setting for thewrite control substrate 39, the charge bias power supply 40, the development bias power supply 41, and the like described above (step S11) to return. Themain CPU 34 proceeds to step S11 when all the alignment marks 25 cannot be discriminated. - When the flags REG_FLG and PRO_FLG are both not equal to 1, the
main CPU 34 determines whether the flag REG_FLG is equal to 1 and whether the flag PRO_FLG is equal to 0 (zero) (step S12). When the flag REG_FLG is equal to 1 and the flag PRO_FLG is equal to 0, themain CPU 34 controls each section of the present embodiment to form only the alignment mark 25 (step S13). Thealignment mark 25 is detected by the detection unit, and the detection signal from this detection unit is stored in theFIFO memory 31 via theamplifier 27, thefilter 28, and the A/D converter 29. The digital data stored in theFIFO memory 31 are loaded into themain CPU 34 and theRAM 35 through the I/O port 32 by the data bus 33 (step S14) after the whole detection of thealignment mark 25 is completed. Themain CPU 34 then performs the arithmetic processing of the data from thealignment mark 25 and the setting for thewrite control substrate 39 as described above (step S15) to return. - When the flag REG_FLG is not equal to 1 and the flag PRO_FLG is not equal to 0, the
main CPU 34 determines whether the flag REG_FLG is equal to 0 and whether the flag PRO_FLG is equal to 1. When the flag REG_FLG is equal to 0 and the flag PRO_FLG is equal to 1, themain CPU 34 controls each section of the present embodiment to form only the image density regulation mark 26 (step S17) The imagedensity regulation mark 26 is detected by the detection unit, and the detection signal from this detection unit is stored in theFIFO memory 31 via theamplifier 27, thefilter 28, and the A/D converter 29. The digital data stored in theFIFO memory 31 are loaded into themain CPU 34 and theRAM 35 through the I/O port 32 by the data bus 33 (step S18) after the whole detection of the imagedensity regulation mark 26 is completed. The main CPU34 then performs the arithmetic processing of the data from the imagedensity regulation mark 26 and the setting for thewrite control substrate 39, the charge bias power supply 40, the development bias power supply 41, and the like as described above (step S19) to return. When the flag REG_FLG is not equal to 0 and the flag PRO_FLG is not equal to 1, themain CPU 34 returns. - With this embodiment, in the color image forming apparatus transferring in superimposing one after another images of the plurality of colors formed in the plurality of image forming units1Y, 1M, 1C, and 1K forming the plural colors of images, respectively, on the transfer paper 2 as a recording medium on the conveyer belt 3 as a conveyer body to obtain a color image on the recording medium, forming a positional deviation detection mark 25 on the conveyer body 3 according to the alignment requirement to detect the positional deviation detection mark 25, performing an alignment for each color by calculating a positional deviation amount of a color against a standard color according to its detection result and correcting a positional deviation of the color against the standard color, forming the image density regulation mark 26 on the conveyer body 2 according to the image density control requirement to detect the image density regulation mark 26, and regulating image density for each color according to its detection result, since the color image forming apparatus comprises the image forming units 1Y, 1M, 1C, and 1K, the detection unit, and the main CPU 34 as means forming and detecting the positional deviation detection mark 25 and the image density regulation mark 26 in the same sequence when the image density control and the alignment are simultaneously required, a waiting time of a user can be shortened.
- Further, when one of either the image density control or the alignment are required, since formation and detection of one of either the positional
deviation detection mark 25 or the imagedensity regulation mark 26 is performed according to the one requirement, it is not necessary to form and detect both of the positional deviation detection mark and the image density regulation mark when one of either the image density control or the alignment is required, whereby a toner consumption can be restrained as much as possible, reducing the running cost. - Moreover, the frequency for sampling the detection signal of the image
density regulation mark 26 and the frequency for sampling the detection signal of the positionaldeviation detection mark 25 are made different. The frequency for sampling the detection signal of the imagedensity regulation mark 26 is less than the frequency for sampling the detection signal of the positionaldeviation detection mark 25. As a result, the time taken for calculation can be shortened by minimizing the data number handled as much as possible, whereby the waiting time of a user can be shortened. - Furthermore, when the discrimination of the positional
deviation detection mark 25 is impossible, only the image density regulation for each color is performed, i.e. the alignment for each color is not performed. When the discrimination is possible, the image density regulation for each color and the alignment for each color are performed. As a result, the alignment can be securely performed. Further, when the discrimination of the positionaldeviation detection mark 25 is impossible, the alignment for each color is performed after the image density regulation for each color is performed. As a result, a clean positional deviation detection mark can be formed after the image density is regulated, whereby the alignment can be securely performed. - The present invention is not limited to the embodiment described above and. For example, this invention can be applied to a color image forming apparatus transferring in superimposing one after another images of a plurality of colors formed in a plurality of image forming units on an intermediate transfer body to transfer the images on a recording medium by a transfer means to fix them by a fixing unit, forming a positional deviation detection mark on the intermediate transfer body to detect the positional deviation detection mark, performing an alignment for each color by calculating a positional deviation amount of a color against a standard color according to its detection result and correcting a positional deviation of the color against the standard color, forming an image density regulation mark on the intermediate transfer body according to an image density control requirement to detect the image density regulation mark, and regulating image density for each color according to its detection result.
- The present document incorporates by reference the entire contents of Japanese priority document, 11-352745 filed in Japan on Dec. 13, 1999.
- Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fail within the basic teaching herein set forth.
Claims (15)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11-352745 | 1999-12-13 | ||
JP35274599A JP2001166553A (en) | 1999-12-13 | 1999-12-13 | Color image forming device |
Publications (2)
Publication Number | Publication Date |
---|---|
US20010004425A1 true US20010004425A1 (en) | 2001-06-21 |
US6381435B2 US6381435B2 (en) | 2002-04-30 |
Family
ID=18426158
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/734,555 Expired - Lifetime US6381435B2 (en) | 1999-12-13 | 2000-12-13 | Color image forming apparatus |
Country Status (2)
Country | Link |
---|---|
US (1) | US6381435B2 (en) |
JP (1) | JP2001166553A (en) |
Cited By (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030053093A1 (en) * | 2001-09-04 | 2003-03-20 | Samsung Electronics Co., Ltd. | Apparatus to control color registration and image density |
US20030137577A1 (en) * | 2001-12-18 | 2003-07-24 | Tadashi Shinohara | Color image forming method and apparatus |
EP1432230A2 (en) * | 2002-12-20 | 2004-06-23 | Ricoh Company, Ltd. | Belt driver, image forming apparatus, and method that can reduce the time until speed control of a belt is provided |
US20050285918A1 (en) * | 2004-06-28 | 2005-12-29 | Mcelligott Michael J | Multiple pass aqueous MICR inkjet ink printing |
US20060061641A1 (en) * | 2004-09-17 | 2006-03-23 | Fuji Xerox Co., Ltd. | Inkjet printing method and image forming apparatus |
US20060177246A1 (en) * | 2005-01-06 | 2006-08-10 | Seiko Epson Corporation | Image forming apparatus |
US20070003302A1 (en) * | 2005-06-30 | 2007-01-04 | Xerox Corporation | Image quality measurements using linear array in specular mode |
US20070230979A1 (en) * | 2006-03-22 | 2007-10-04 | Shin Hasegawa | Image forming apparatus effectively conducting a process control |
US20080019740A1 (en) * | 2006-07-24 | 2008-01-24 | Konica Minolta Business Technologies Inc. | Image forming apparatus and image forming method |
US20080043299A1 (en) * | 2006-08-21 | 2008-02-21 | Ricoh Company, Limited | Image forming apparatus, image formation control method, and computer program product |
US20080152398A1 (en) * | 2006-12-20 | 2008-06-26 | Samsung Electronics Co., Ltd | Image forming apparatus and control method thereof |
US20080292369A1 (en) * | 2007-05-21 | 2008-11-27 | Canon Kabushiki Kaisha | Imaging forming apparatus and method of controlling same |
US20090035030A1 (en) * | 2007-07-31 | 2009-02-05 | Samsung Electronics Co., Ltd | Image forming apparatus and auto color registration method thereof |
EP1936943A3 (en) * | 2006-12-20 | 2009-11-04 | Samsung Electronics Co., Ltd. | Image forming apparatus and control method thereof |
US7734234B2 (en) * | 2006-07-11 | 2010-06-08 | Ricoh Company, Limited | Positional-deviation correction apparatus, method of controlling positional deviation, and image forming apparatus |
US8588651B2 (en) | 2010-05-25 | 2013-11-19 | Ricoh Company, Ltd. | Rotary drive device with a planetary gear mechanism to drive a rotary body, and image forming apparatus including the same |
KR20130126487A (en) * | 2012-05-11 | 2013-11-20 | 캐논 가부시끼가이샤 | Image forming apparatus for performing registration and density correction control |
EP2682818A1 (en) * | 2012-05-11 | 2014-01-08 | Canon Kabushiki Kaisha | Image forming apparatus for detecting misregistration amount and density |
US20140175289A1 (en) * | 2012-12-21 | 2014-06-26 | R. John Voorhees | Conveyer Belt with Optically Visible and Machine-Detectable Indicators |
US9048687B2 (en) | 2011-10-19 | 2015-06-02 | Ricoh Company, Limited | Power supply device and control method for power supply |
US9141049B2 (en) | 2010-12-15 | 2015-09-22 | Konica Minolta, Inc. | Image forming apparatus and temperature control method in fixing device thereof for controlling temperature of fixing device to be at target temperature after execution of non-image formation device |
US9201331B2 (en) | 2012-09-13 | 2015-12-01 | Ricoh Company, Limited | Image forming apparatus, image correcting method, computer readable storage medium, image correction unit and image forming system |
US20160034231A1 (en) * | 2014-07-30 | 2016-02-04 | Canon Kabushiki Kaisha | Printing apparatus and print control method |
US20170153588A1 (en) * | 2015-11-30 | 2017-06-01 | Canon Kabushiki Kaisha | Image forming apparatus using test images to adjust position of latent image |
EP2685315B1 (en) * | 2012-05-11 | 2019-12-04 | Canon Kabushiki Kaisha | Image forming apparatus for performing registration and density correction control |
Families Citing this family (82)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6608984B1 (en) | 1999-04-23 | 2003-08-19 | Ricoh Company, Ltd. | Image forming method and apparatus using developer carrier pressed into engagement with image carrier |
AU5387800A (en) * | 1999-04-26 | 2000-11-10 | Phoenix Ag | Device for coding and marking objects |
CN1900837B (en) | 2000-02-17 | 2012-10-03 | 株式会社理光 | Toner storing device, toner replenishing method and device |
JP4167807B2 (en) | 2000-03-10 | 2008-10-22 | 株式会社リコー | Image forming apparatus and toner storage container |
JP3849971B2 (en) | 2000-03-16 | 2006-11-22 | 株式会社リコー | Products that can be checked for deterioration |
US6591077B2 (en) | 2000-05-08 | 2003-07-08 | Ricoh Company, Ltd. | Image forming apparatus and toner container therefor |
JP4190160B2 (en) | 2000-06-05 | 2008-12-03 | 株式会社リコー | Image forming apparatus |
JP2002091123A (en) | 2000-07-14 | 2002-03-27 | Ricoh Co Ltd | Color image forming device and toner replenishing device |
US7619130B2 (en) * | 2000-07-18 | 2009-11-17 | Coloplast A/S | Multi-layer wound dressing formed as a single unit |
JP4351814B2 (en) | 2000-07-21 | 2009-10-28 | 株式会社リコー | Color image forming apparatus |
JP2002046843A (en) * | 2000-07-31 | 2002-02-12 | Ricoh Co Ltd | Powder supply device, powder transfer device, developing device and image forming device |
JP2002055292A (en) | 2000-08-11 | 2002-02-20 | Ricoh Co Ltd | Optical scanner |
US6573918B2 (en) | 2000-08-22 | 2003-06-03 | Ricoh Company, Ltd. | Image forming apparatus having a plurality of image data interfaces |
JP2002072645A (en) | 2000-08-31 | 2002-03-12 | Ricoh Co Ltd | Powder replenishing unit, developing unit and image forming apparatus |
EP1826626B1 (en) | 2000-09-27 | 2012-12-05 | Ricoh Company, Ltd. | Apparatuses for color image formation, tandem color image formation and image formation |
JP3958511B2 (en) | 2000-09-28 | 2007-08-15 | 株式会社リコー | Toner supply device and image forming apparatus |
US6542707B2 (en) | 2000-11-13 | 2003-04-01 | Ricoh Co., Ltd. | Method and apparatus for image forming capable of effectively transferring various kinds of powder |
JP4042127B2 (en) | 2001-01-10 | 2008-02-06 | 株式会社リコー | Color image forming apparatus |
JP2002207338A (en) | 2001-01-10 | 2002-07-26 | Ricoh Co Ltd | Method and device for detecting color deviation in color image formation and color image forming device |
US6665508B2 (en) * | 2001-01-31 | 2003-12-16 | Ricoh Company, Ltd. | Toner container and image forming apparatus using the same |
US6597883B2 (en) | 2001-02-13 | 2003-07-22 | Ricoh Company, Ltd. | Powder pump capable of effectively conveying powder and image forming apparatus using powder pump |
JP2002244488A (en) | 2001-02-13 | 2002-08-30 | Ricoh Co Ltd | Latent image carrier and image forming device |
JP2002351287A (en) | 2001-03-23 | 2002-12-06 | Ricoh Co Ltd | Imaging unit and image forming device |
JP2003043862A (en) * | 2001-05-23 | 2003-02-14 | Ricoh Co Ltd | Latent image carrier, image forming device, and vibration damping member |
JP3570714B2 (en) | 2001-05-24 | 2004-09-29 | 株式会社リコー | Developer container and image forming apparatus |
JP4121333B2 (en) * | 2001-08-27 | 2008-07-23 | 株式会社リコー | Image forming apparatus, program update method, and recording medium |
JP4083505B2 (en) * | 2001-08-27 | 2008-04-30 | 株式会社リコー | Image forming apparatus, program update method, and recording medium |
JP2003084530A (en) | 2001-09-14 | 2003-03-19 | Ricoh Co Ltd | Color image forming apparatus |
JP3640629B2 (en) | 2001-09-21 | 2005-04-20 | 株式会社リコー | Color image forming apparatus |
JP2003173069A (en) * | 2001-09-25 | 2003-06-20 | Ricoh Co Ltd | Charging device, image forming unit, and image forming device |
JP4095875B2 (en) * | 2001-10-30 | 2008-06-04 | 株式会社リコー | Developer container and image forming apparatus |
JP2003241512A (en) * | 2002-02-15 | 2003-08-29 | Ricoh Co Ltd | Image forming apparatus |
JP3934473B2 (en) * | 2002-05-09 | 2007-06-20 | 大日本スクリーン製造株式会社 | Patch measuring device and printing device incorporating the same |
JP2003330218A (en) * | 2002-05-17 | 2003-11-19 | Ricoh Co Ltd | Toner, toner carrying apparatus and image forming apparatus |
US7542703B2 (en) * | 2002-05-20 | 2009-06-02 | Ricoh Company, Ltd. | Developing device replenishing a toner or a carrier of a two-ingredient type developer and image forming apparatus including the developing device |
JP3684212B2 (en) | 2002-06-05 | 2005-08-17 | 株式会社リコー | Volume reduction method for developer container, developer supply device, and image forming apparatus |
JP4021712B2 (en) * | 2002-06-13 | 2007-12-12 | 株式会社リコー | Electrophotographic image forming apparatus and copying machine |
US7058335B2 (en) * | 2002-06-14 | 2006-06-06 | Ricoh Company, Ltd. | Process cartridge and image forming apparatus with toner fed cleaning mode |
JP4037189B2 (en) * | 2002-07-04 | 2008-01-23 | 株式会社リコー | Electrophotographic cleanerless color image forming apparatus |
JP3773884B2 (en) * | 2002-09-04 | 2006-05-10 | 株式会社リコー | Image forming apparatus |
JP4220798B2 (en) * | 2002-09-20 | 2009-02-04 | 株式会社リコー | Powder container |
JP3604683B2 (en) * | 2002-09-24 | 2004-12-22 | 株式会社リコー | Color image forming apparatus, tandem drum type color image forming apparatus, and process cartridge used in color image forming apparatus |
US7116928B2 (en) * | 2002-12-18 | 2006-10-03 | Ricoh Company, Ltd. | Powder discharging device and image forming apparatus using the same |
US7103301B2 (en) * | 2003-02-18 | 2006-09-05 | Ricoh Company, Ltd. | Image forming apparatus using a contact or a proximity type of charging system including a protection substance on a moveable body to be charged |
JP2005017787A (en) | 2003-06-27 | 2005-01-20 | Ricoh Co Ltd | Toner replenishing device |
JP2005031263A (en) * | 2003-07-09 | 2005-02-03 | Ricoh Co Ltd | Image forming device |
EP1498785B1 (en) * | 2003-07-18 | 2015-12-09 | Ricoh Company, Ltd. | Image forming apparatus with a speed control of a belt |
JP2005037628A (en) * | 2003-07-18 | 2005-02-10 | Ricoh Co Ltd | Image forming apparatus |
JP4272565B2 (en) * | 2003-07-18 | 2009-06-03 | 株式会社リコー | Belt drive control device and image forming apparatus |
US7162171B2 (en) * | 2003-08-22 | 2007-01-09 | Ricoh Company, Ltd. | Method, system and software program for correcting positional color misalignment |
JP2005077469A (en) * | 2003-08-28 | 2005-03-24 | Ricoh Co Ltd | Image forming apparatus |
JP2005075529A (en) * | 2003-08-29 | 2005-03-24 | Ricoh Co Ltd | Belt drive control device, process cartridge and image forming apparatus |
US7576509B2 (en) * | 2003-09-10 | 2009-08-18 | Ricoh Company, Limited | Drive control method, drive control device, belt apparatus, image forming apparatus, image reading apparatus, computer product |
US20050058474A1 (en) * | 2003-09-17 | 2005-03-17 | Kazuhiko Watanabe | Cleaning device, process cartridge, and image forming apparatus |
JP2005091797A (en) * | 2003-09-18 | 2005-04-07 | Ricoh Co Ltd | Developing method and developing device |
JP4330962B2 (en) * | 2003-09-18 | 2009-09-16 | 株式会社リコー | Developer container, developer supply device, and image forming apparatus |
JP4587269B2 (en) * | 2003-10-27 | 2010-11-24 | 株式会社リコー | Process cartridge replacement method, device unit replacement method |
US7110917B2 (en) | 2003-11-14 | 2006-09-19 | Ricoh Company, Ltd. | Abnormality determining method, and abnormality determining apparatus and image forming apparatus using same |
JP4323939B2 (en) * | 2003-12-11 | 2009-09-02 | キヤノン株式会社 | Image forming apparatus and image forming method |
JP2005181711A (en) * | 2003-12-19 | 2005-07-07 | Ricoh Co Ltd | Image forming apparatus and process cartridge |
US7035558B2 (en) * | 2004-02-11 | 2006-04-25 | Hewlett-Packard Development Company, L.P. | Method of detecting a rotation of print cartridge components |
JP4451674B2 (en) * | 2004-02-13 | 2010-04-14 | 京セラミタ株式会社 | Image forming apparatus |
JP4693026B2 (en) * | 2004-03-18 | 2011-06-01 | 株式会社リコー | Image forming apparatus and method for controlling the apparatus |
CN100418019C (en) * | 2004-06-30 | 2008-09-10 | 株式会社理光 | Color image forming apparatus and method of controlling the color image forming apparatus |
JP4813832B2 (en) * | 2005-07-06 | 2011-11-09 | 株式会社リコー | Color image forming apparatus |
JP2007041128A (en) * | 2005-08-01 | 2007-02-15 | Ricoh Co Ltd | Color image forming apparatus |
JP4587479B2 (en) | 2005-08-31 | 2010-11-24 | キヤノン株式会社 | Image forming apparatus and density adjustment method thereof |
JP2007125738A (en) * | 2005-11-01 | 2007-05-24 | Ricoh Co Ltd | Optical recording device and image forming device |
JP2007128006A (en) * | 2005-11-07 | 2007-05-24 | Ricoh Co Ltd | Image forming apparatus and control circuit for the image forming apparatus |
JP4865310B2 (en) * | 2005-11-30 | 2012-02-01 | 株式会社リコー | Correction pattern forming method and color image forming apparatus |
JP5057747B2 (en) * | 2005-11-30 | 2012-10-24 | 株式会社リコー | Image forming apparatus, image forming operation correction method, and program for causing computer to execute image forming operation correction method |
JP4427568B2 (en) * | 2007-07-04 | 2010-03-10 | シャープ株式会社 | Image forming apparatus |
KR101239953B1 (en) | 2007-07-31 | 2013-03-06 | 삼성전자주식회사 | Image forming apparatus and auto color registration method thereof |
JP5219475B2 (en) * | 2007-11-30 | 2013-06-26 | キヤノン株式会社 | Color image forming apparatus and control method thereof |
JP5434694B2 (en) * | 2009-03-18 | 2014-03-05 | 株式会社リコー | Misalignment correction method, misalignment correction apparatus, and image forming apparatus using the same |
JP5392156B2 (en) * | 2010-03-16 | 2014-01-22 | 株式会社リコー | Image forming apparatus |
JP2011196450A (en) * | 2010-03-18 | 2011-10-06 | Ricoh Co Ltd | Driving device and image forming apparatus |
JP5787432B2 (en) * | 2010-10-19 | 2015-09-30 | 橋本電子工業株式会社 | How to process large numbers of fish eggs |
JP6112778B2 (en) | 2012-05-11 | 2017-04-12 | キヤノン株式会社 | Image forming apparatus, density detection pattern detection method, and formation method |
JP2014109623A (en) * | 2012-11-30 | 2014-06-12 | Ricoh Co Ltd | Image forming apparatus |
JP6018559B2 (en) * | 2013-10-18 | 2016-11-02 | キヤノン株式会社 | Image forming apparatus |
JP6302329B2 (en) | 2014-04-02 | 2018-03-28 | キヤノン株式会社 | Image forming apparatus |
Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63279280A (en) * | 1987-05-12 | 1988-11-16 | Ricoh Co Ltd | Image forming device |
JP2642351B2 (en) | 1987-05-19 | 1997-08-20 | 株式会社リコー | Image forming device |
JP2573855B2 (en) | 1987-12-23 | 1997-01-22 | キヤノン株式会社 | Multiple image forming device |
JPH01179955A (en) * | 1988-01-12 | 1989-07-18 | Canon Inc | Registration correcting device |
JP3288072B2 (en) | 1992-06-16 | 2002-06-04 | キヤノン株式会社 | Image forming device |
JP3514398B2 (en) | 1994-12-07 | 2004-03-31 | 株式会社リコー | Image forming device |
US5799228A (en) | 1995-06-09 | 1998-08-25 | Ricoh Company, Ltd. | Image forming apparatus which prevents adverse affects from heating elements |
JP3527352B2 (en) | 1996-02-26 | 2004-05-17 | 株式会社リコー | Color image forming apparatus |
JP2765626B2 (en) | 1996-03-06 | 1998-06-18 | 株式会社リコー | Image forming device |
JP3570701B2 (en) | 1996-11-11 | 2004-09-29 | 株式会社リコー | Image forming device |
JPH10198110A (en) | 1996-11-18 | 1998-07-31 | Ricoh Co Ltd | Color image forming method |
JPH10260567A (en) * | 1997-01-20 | 1998-09-29 | Ricoh Co Ltd | Color image forming device |
US5875380A (en) | 1997-02-18 | 1999-02-23 | Ricoh Company, Ltd. | Image forming apparatus eliminating influence of fluctuation in speed of a conveying belt to correction of offset in color registration |
JP3745515B2 (en) * | 1997-09-26 | 2006-02-15 | 株式会社リコー | Color image forming apparatus |
JPH11160952A (en) * | 1997-11-21 | 1999-06-18 | Canon Inc | Image forming device |
-
1999
- 1999-12-13 JP JP35274599A patent/JP2001166553A/en active Pending
-
2000
- 2000-12-13 US US09/734,555 patent/US6381435B2/en not_active Expired - Lifetime
Cited By (54)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030053093A1 (en) * | 2001-09-04 | 2003-03-20 | Samsung Electronics Co., Ltd. | Apparatus to control color registration and image density |
US20100028058A1 (en) * | 2001-09-04 | 2010-02-04 | Samsung Electronics Co., Ltd. | Apparatus to control color registration and image density |
US7658462B2 (en) * | 2001-09-04 | 2010-02-09 | Samsung Electronics Co., Ltd | Apparatus to control color registration and image density |
US8136904B2 (en) * | 2001-09-04 | 2012-03-20 | Samsung Electronics Co., Ltd. | Apparatus to control color registration and image density |
US20120141146A1 (en) * | 2001-09-04 | 2012-06-07 | Samsung Electronics Co., Ltd. | Apparatus to control color registration and image density |
US20030137577A1 (en) * | 2001-12-18 | 2003-07-24 | Tadashi Shinohara | Color image forming method and apparatus |
EP1321827A3 (en) * | 2001-12-18 | 2004-04-21 | Ricoh Company, Ltd. | Color image forming method and apparatus |
EP1432230A2 (en) * | 2002-12-20 | 2004-06-23 | Ricoh Company, Ltd. | Belt driver, image forming apparatus, and method that can reduce the time until speed control of a belt is provided |
EP1432230A3 (en) * | 2002-12-20 | 2005-03-30 | Ricoh Company, Ltd. | Belt driver, image forming apparatus, and method that can reduce the time until speed control of a belt is provided |
US7133627B2 (en) | 2002-12-20 | 2006-11-07 | Ricoh Company, Ltd. | Belt driver, image forming apparatus, and method that can reduce the time until speed control of a belt is performed |
US20050285918A1 (en) * | 2004-06-28 | 2005-12-29 | Mcelligott Michael J | Multiple pass aqueous MICR inkjet ink printing |
US7255433B2 (en) * | 2004-06-28 | 2007-08-14 | Nu-Kote International, Inc. | Multiple pass aqueous MICR inkjet ink printing |
US7438406B2 (en) * | 2004-09-17 | 2008-10-21 | Fuji Xerox Co., Ltd. | Inkjet printing method and image forming apparatus |
US20060061641A1 (en) * | 2004-09-17 | 2006-03-23 | Fuji Xerox Co., Ltd. | Inkjet printing method and image forming apparatus |
US20060177246A1 (en) * | 2005-01-06 | 2006-08-10 | Seiko Epson Corporation | Image forming apparatus |
US7417651B2 (en) * | 2005-01-06 | 2008-08-26 | Seiko Epson Corporation | Image forming apparatus |
US7272333B2 (en) * | 2005-06-30 | 2007-09-18 | Xerox Corporation | Image quality measurements using linear array in specular mode |
US20070003302A1 (en) * | 2005-06-30 | 2007-01-04 | Xerox Corporation | Image quality measurements using linear array in specular mode |
US20070230979A1 (en) * | 2006-03-22 | 2007-10-04 | Shin Hasegawa | Image forming apparatus effectively conducting a process control |
US7548704B2 (en) * | 2006-03-22 | 2009-06-16 | Ricoh Co., Ltd. | Image forming apparatus effectively conducting a process control |
US7734234B2 (en) * | 2006-07-11 | 2010-06-08 | Ricoh Company, Limited | Positional-deviation correction apparatus, method of controlling positional deviation, and image forming apparatus |
US20080019740A1 (en) * | 2006-07-24 | 2008-01-24 | Konica Minolta Business Technologies Inc. | Image forming apparatus and image forming method |
US7952774B2 (en) * | 2006-08-21 | 2011-05-31 | Ricoh Company, Limited | Image forming apparatus, image formation control method, and computer program product |
US20080043299A1 (en) * | 2006-08-21 | 2008-02-21 | Ricoh Company, Limited | Image forming apparatus, image formation control method, and computer program product |
EP1936943A3 (en) * | 2006-12-20 | 2009-11-04 | Samsung Electronics Co., Ltd. | Image forming apparatus and control method thereof |
US8379067B2 (en) | 2006-12-20 | 2013-02-19 | Samsung Electronics Co., Ltd. | Image forming apparatus and control method thereof |
EP2506553A3 (en) * | 2006-12-20 | 2014-08-13 | Samsung Electronics Co., Ltd. | Image forming apparatus and control method thereof |
US20080152398A1 (en) * | 2006-12-20 | 2008-06-26 | Samsung Electronics Co., Ltd | Image forming apparatus and control method thereof |
US8040365B2 (en) | 2006-12-20 | 2011-10-18 | Samsung Electronics Co., Ltd. | Image forming apparatus and control method thereof |
US20080292369A1 (en) * | 2007-05-21 | 2008-11-27 | Canon Kabushiki Kaisha | Imaging forming apparatus and method of controlling same |
US20110176843A1 (en) * | 2007-05-21 | 2011-07-21 | Canon Kabushiki Kaisha | Imaging forming apparatus and method of controlling same |
US7937032B2 (en) * | 2007-05-21 | 2011-05-03 | Canon Kabushiki Kaisha | Imaging forming apparatus and method of controlling same |
US8131193B2 (en) | 2007-05-21 | 2012-03-06 | Canon Kabushiki Kaisha | Imaging forming apparatus and method of controlling same |
US8244165B2 (en) | 2007-05-21 | 2012-08-14 | Canon Kabushiki Kaisha | Imaging forming apparatus and method of controlling same |
US8472851B2 (en) | 2007-05-21 | 2013-06-25 | Canon Kabushiki Kaisha | Imaging forming apparatus and method of controlling same |
US7848690B2 (en) | 2007-07-31 | 2010-12-07 | Samsung Electronics Co., Ltd. | Image forming apparatus and auto color registration method thereof |
US20090035030A1 (en) * | 2007-07-31 | 2009-02-05 | Samsung Electronics Co., Ltd | Image forming apparatus and auto color registration method thereof |
EP2026553A2 (en) | 2007-07-31 | 2009-02-18 | Samsung Electronics Co., Ltd. | Image forming apparatus and auto color registration method thereof |
EP2026553A3 (en) * | 2007-07-31 | 2009-08-19 | Samsung Electronics Co., Ltd. | Image forming apparatus and auto color registration method thereof |
US8588651B2 (en) | 2010-05-25 | 2013-11-19 | Ricoh Company, Ltd. | Rotary drive device with a planetary gear mechanism to drive a rotary body, and image forming apparatus including the same |
US9141049B2 (en) | 2010-12-15 | 2015-09-22 | Konica Minolta, Inc. | Image forming apparatus and temperature control method in fixing device thereof for controlling temperature of fixing device to be at target temperature after execution of non-image formation device |
US9048687B2 (en) | 2011-10-19 | 2015-06-02 | Ricoh Company, Limited | Power supply device and control method for power supply |
US9594337B2 (en) | 2012-05-11 | 2017-03-14 | Canon Kabushiki Kaisha | Image forming apparatus for detecting misregistration amount and density |
KR20130126487A (en) * | 2012-05-11 | 2013-11-20 | 캐논 가부시끼가이샤 | Image forming apparatus for performing registration and density correction control |
KR101681359B1 (en) | 2012-05-11 | 2016-12-12 | 캐논 가부시끼가이샤 | Image forming apparatus for performing registration and density correction control |
EP2682818A1 (en) * | 2012-05-11 | 2014-01-08 | Canon Kabushiki Kaisha | Image forming apparatus for detecting misregistration amount and density |
EP2685315B1 (en) * | 2012-05-11 | 2019-12-04 | Canon Kabushiki Kaisha | Image forming apparatus for performing registration and density correction control |
US9201331B2 (en) | 2012-09-13 | 2015-12-01 | Ricoh Company, Limited | Image forming apparatus, image correcting method, computer readable storage medium, image correction unit and image forming system |
US20140175289A1 (en) * | 2012-12-21 | 2014-06-26 | R. John Voorhees | Conveyer Belt with Optically Visible and Machine-Detectable Indicators |
US20160034231A1 (en) * | 2014-07-30 | 2016-02-04 | Canon Kabushiki Kaisha | Printing apparatus and print control method |
US9411544B2 (en) * | 2014-07-30 | 2016-08-09 | Canon Kabushiki Kaisha | Printing apparatus and print control method controlling printing based on acquired information relating to conveyance of a print medium |
US20170153588A1 (en) * | 2015-11-30 | 2017-06-01 | Canon Kabushiki Kaisha | Image forming apparatus using test images to adjust position of latent image |
CN106919020A (en) * | 2015-11-30 | 2017-07-04 | 佳能株式会社 | Image forming apparatus |
US10281861B2 (en) * | 2015-11-30 | 2019-05-07 | Canon Kabushiki Kaisha | Image forming apparatus using test images to adjust position of latent image |
Also Published As
Publication number | Publication date |
---|---|
JP2001166553A (en) | 2001-06-22 |
US6381435B2 (en) | 2002-04-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6381435B2 (en) | Color image forming apparatus | |
JP3644923B2 (en) | Color image forming method and color image forming apparatus | |
US7260335B2 (en) | Image-information detecting device and image forming apparatus | |
US7821677B2 (en) | Method and apparatus for image forming capable of accurately detecting displacement of transfer images and image density | |
JP4710702B2 (en) | Color image forming apparatus | |
US6380960B1 (en) | Color image forming apparatus with position compensation | |
US7389075B2 (en) | Image forming apparatus, program and positional error correction method | |
US8503895B2 (en) | Image forming apparatus capable of stably controlling image density | |
JPH10260567A (en) | Color image forming device | |
US6934498B2 (en) | Color image forming apparatus, tandem type color image forming apparatus, and process cartridge for color image forming apparatus | |
JP2006201484A (en) | Image forming apparatus | |
US5600404A (en) | Correction of misregistration in an image forming apparatus depending on multiple regions of a transfer belt | |
US6335747B1 (en) | Image forming apparatus, adjustment method and memory medium | |
US7581803B2 (en) | Image forming apparatus, method and computer readable medium for executing predetermined error processes in response to a moveable member error | |
JP3745515B2 (en) | Color image forming apparatus | |
JPH103188A (en) | Color image forming device | |
US6393244B1 (en) | Color shift correcting structure of image forming apparatus | |
JP2000221738A (en) | Image forming device | |
JP2007041128A (en) | Color image forming apparatus | |
US6137981A (en) | Apparatus for forming multiple toner images in register with each other on a substrate | |
JP2000112205A (en) | Color image forming device | |
JP2003307902A (en) | Image forming device | |
JP2005091901A (en) | Color image forming apparatus | |
JPH07306624A (en) | Tandem type color image forming device | |
EP0973072B1 (en) | Apparatus for forming multiple toner images in register with each other on a substrate |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: RICOH COMPANY, LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SHINOHARA, TADASHI;NAKAZATO, YASUSHI;SATO, TOSHIYA;AND OTHERS;REEL/FRAME:011545/0318 Effective date: 20010201 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 12 |