JPH0684076B2 - Inkjet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention forms ink particles of two sizes, large and small, alternately in size, and independently and reliably charges and deflects these particles. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for recording by means of recording, and more particularly to an ink jet recording apparatus provided with a device for appropriately improving a nozzle excitation state in order to reliably generate particles and charge them.

[Conventional technology]

The ink jet recording apparatus to which the present invention is applied is disclosed in
This is an ink jet recording apparatus as described in JP-A-54-41329. That is, ink particles of two sizes, large and small, that is, large particles and small particles, are alternately generated, and these particles are charged and deflected according to a recording signal to control the adhesion of the ink particles to the recording paper. It is an ink jet recording device for recording.

In such an ink jet recording apparatus, in order to always perform good recording even if the environmental temperature or the ink physical properties change in the recording apparatus, in order to always generate large and small diameter ink particles properly and charge them, A device for setting the excitation condition shall be provided.

As such an apparatus, prior to image recording, the excitation voltage of the nozzle is swept over a wide range to investigate the particle generation characteristics, and the optimum excitation voltage that can reliably generate and charge small-diameter particles is set. Some will start recording after that.

[Problems to be solved by the invention]

However, in a recording apparatus in which it takes several minutes or more to finish writing one screen, even if the nozzle excitation voltage is set to an appropriate value before the start of recording, the particle creation state changes during the recording operation, and the excitation The voltage may deviate from the proper value and the recording may be disturbed. In order to eliminate such an inconvenience, the optimum excitation voltage setting operation as described above may be repeatedly inserted in the middle of image recording. However, since this operation takes a long time, the recording time required for one screen is increased. This leads to the drawback of a longer length.

An object of the present invention is to provide an ink jet recording capable of always reliably generating and charging ink particles even if it takes a long time to finish recording due to a large screen to be recorded, and that the time required therefor can be shortened. To provide a device.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention changes the excitation condition of the nozzle over a wide range within the range where small particles are generated, and the optimum excitation condition that can reliably generate and charge the small particles is provided. Nozzle excitation condition optimization main operation executing means to be set, the excitation condition is changed within a narrow range near the nozzle excitation condition obtained by the means, and optimum with the lapse of time after execution of the nozzle excitation condition optimization main operation Check the fluctuation of the condition and reset the nozzle excitation condition to the optimum condition. Nozzle excitation condition optimization fine correction operation execution means, divides one screen to be recorded into a plurality of image blocks, and terminates the recording of each image block. Image block recording end identifying means for identifying, prior to the start of recording of one screen, the main operation for optimizing the nozzle excitation condition is executed, then recording is executed, and the image block recording is performed. In response to the information from the end identification means, at least a part of the nozzle excitation condition optimization fine-correction operation is executed, the recording of the next image block is executed after the completion of the operation, the recording execution of the image block and the nozzle excitation condition are executed. It is characterized in that a control calculation device for controlling each of the above means is provided so that the execution of the optimization fine correction operation is alternately repeated and the recording of one screen is completed.

[Action]

The nozzle excitation condition optimization main operation is executed prior to the start of recording one screen, and then the recording is executed. Upon receipt of information from the image block recording end identifying means, the nozzle excitation condition optimization fine correction operation is performed. At least a part of the above is executed, the recording of the next image block is executed after the end of the operation, and the recording of the image block and the execution of the nozzle excitation condition optimization fine correction operation are alternately repeated to complete the recording of one screen. .

〔Example〕

FIG. 1 shows an embodiment of the present invention in which the following recording operation is performed well.

Pressurized ink is supplied to the ink particle producing apparatus in which the piezoelectric element 2 is attached to the nozzle 1, and the ink ejected from the nozzle 1 is alternately separated into large-diameter particles 3a and small-diameter particles 3b. Then, only the small particles 3b among them are controlled by the control electrodes 4a and 4b in response to the recording signal.
The recording is performed by deflecting the electric charge with the recording medium and wiping it onto the recording medium 6 wound around the rotating drum 5.

According to the present invention, this ink jet recording apparatus is configured to include the following means.

That is, the excitation voltage to the nozzle 1 is changed over a wide range, the generation state of the ink particles is checked, and the excitation voltage is set to the optimum value. The nozzle excitation condition optimization main operation executing means A, the nozzle obtained by this means. Nozzle excitation condition optimization fine adjustment means B, image block recording end identification means C, which changes the excitation voltage within a narrow range near the excitation voltage to check the movement of the optimum excitation voltage and corrects the excitation voltage to an optimum value, and these It includes a control calculation device D for performing various controls and calculations including means.

Here, the image block in this embodiment means an image portion recorded by one rotation of the drum, and one recording screen is constituted as a group of the image blocks. Then, a portion where the recording paper is not wound is provided around a predetermined peripheral portion extending in the axial direction of the drum, and this portion is detected by the sensor 7 for each rotation of the drum, and the level is converted by the level conversion circuit 8, whereby the image block recording is performed. The end can be identified.

The main execution means A and the fine correction means B for optimizing the nozzle excitation condition use almost common parts in terms of hardware, but their operations are different as described later.

The hardware of the common part switches whether to use the control electrodes 4a and 4b for recording operation or to optimize the excitation condition.
Japanese Patent Application No. 59-17 for measuring the charge amount of particles from a control electrode through the electrode switching circuit 11 as disclosed in Japanese Patent No. 61
From a sense amplifier 12 as shown in the specification and drawings of 5057, a switching circuit 14 for checking the generation state of ink particles, a test signal source 13 for sending a test signal to an electrode through a video amplifier 16, and a control calculation device D. The excitation voltage varying device 17 for controlling the magnitude of the excitation voltage applied to the piezoelectric element 2 according to the above command.

The operation will be described below with reference to the operation flow chart of FIG. 2 and the explanatory view of FIG.

When the recording start command is input, first, the nozzle excitation condition optimizing main operation is executed prior to the actual recording operation.

That is, by applying a test signal with a pulse width T / 6 of about 1/6 of the nozzle excitation period T to the electrode 4a, the electrode switching is performed so that the charged state of the ink particles can be detected from the electrode 4b via the sense amplifier 12. The circuit 11 and the switching circuit 14 are set. Then, a test signal is generated each time while changing the excitation voltage in a wide range (about 20 to 200V _DD ) at least within the range where small particles are generated, and the output of the sense amplifier at each excitation voltage value is controlled. Enter and memorize. An example of the signal output is shown in FIG.

The excitation voltage value showing a small peak here indicates that small-sized ink particles were generated and could be charged by the test signal, and the large peak was generated by large-sized particles or large and small-sized coalesced particles and could be charged by the test signal. It means something. Therefore, when the excitation voltage is set to V ₂ in the figure, the distances W ₁ and W _{2 from} the peak values of the large particles on both sides are almost equal,
The recording signal with the same phase as the test signal and a pulse width value of about T / 2 can most reliably charge the small particles.

Therefore, the calculation control device D automatically finds this V ₂ and sets the excitation voltage value to this value. This is the main operation for optimizing the nozzle excitation conditions. This operation is further detailed in the specification and drawings of Japanese Patent Application No. 60-41327.

When the main operation for optimizing the nozzle excitation conditions is completed, the recording signal from the recording signal source 15 is controlled so as to be applied to the control electrodes 4a and 4b through the electrode switching circuit 11 and the switching circuit 14, and actually, Is recorded.

When the recording of one image block or a predetermined block is executed, the image block recording end identifying means C detects the end of recording. Then, the nozzle excitation condition optimization fine correction means B is activated by this detection, and at least part of this operation is executed.

In the nozzle excitation condition optimization fine correction operation, first, the electrical switching circuit 11 and the video switching circuit 14 are switched to the optimization execution state at high speed similarly to the main operation. Then, the particle formation state in a narrow voltage range around the nozzle excitation voltage V ₂ set in the main operation is checked. That is, the excitation voltage value at which the sense-up output peaks is obtained as the proper excitation voltage. And when properly excited voltage as in the third view (b) is not shifted from the excitation voltage set in Men'i operation, keeping the drive voltage directly to V _2, also when shifted as (c), V ₂ Change the setting voltage from V ₃ to V ₃ . By this operation, the proper state can be changed and followed while recording for a long time.

In this way, the range of the excitation to be investigated by the fine correction operation is
The operation can be completed in a short time. However, if all the operations cannot be completed within one image block time, for example, one point data of the nozzle excitation voltage value is sampled between one image block and the next one point data is collected between the next image blocks. Thus, it is possible to collect a series of data between a plurality of image blocks, analyze the data, optimize the excitation voltage, and finish the fine correction operation.

Optimizing nozzle excitation conditions between image blocks After the fine correction operation is completed, promptly switch the electrode switching circuit 11 and switching circuit 14
A recording signal is applied to the switching control electrodes 4a and 4b to record the next image block.

Recording of one screen is completed while repeating the above-described image block recording operation and the nozzle excitation condition optimization fine correction operation.

In the above description, an example in which the excitation condition of the nozzle is optimized by the excitation voltage has been described. However, for example, a method of changing the excitation waveform for exciting the nozzle may be used.

Incidentally, in this embodiment, the number of data samplings in the main operation for optimizing the nozzle excitation condition is set to 500, and the number of data samplings in the main operation for optimizing the nozzle excitation condition is set to 9.

〔The invention's effect〕

According to the present invention, good recording can be performed by always reliably controlling the generation and charge of ink particles even if it takes a long time to finish recording due to a large recording screen. Moreover, since the time required for the control is small, it is possible to reduce the increase in the time required for full-surface recording.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an operation flow chart, and FIGS. 3 (a) to 3 (c) are signal waveform diagrams for explaining the operation. A: Nozzle excitation condition optimization main operation execution means, B ...
... Fine adjustment means for optimizing nozzle excitation conditions, C ... Image block recording end identification means, D ... Control calculation device, 1 ... Nozzle, 2 ... Piezoelectric element, 3a ... Large particle, 3b ... Small particle , 4a, 4b ... Control electrodes, 5 ... Rotating drum, 6 ... Recording paper, 7 ... Sensor, 8 ... Level conversion circuit, 11 ... Electrode switching circuit, 12 ... Sense up, 13 ... Test signal Source, 14 ... Switching circuit, 15 ... Recording signal source, 16 ...
… Video amplifier, 17… Excitation voltage variable device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Namegawa 2-6-2 Otemachi, Chiyoda-ku, Tokyo Within Nitse Seiko Co., Ltd. (72) Inventor Yasumasa Matsuda 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Ceremony Company Hitachi, Ltd. Microelectronics Equipment Development Laboratory (72) Inventor Masatoshi Sakata 2-6-2 Otemachi, Chiyoda-ku, Tokyo Hirt Seiko Co., Ltd. (72) Inventor Shoji Nagamori Otemachi, Chiyoda-ku, Tokyo 2-6-2 Hiritsu Seiko Co., Ltd. (56) Reference JP-A-56-86769 (JP, A) JP-B-3-42581 (JP, B2)

Claims (1)

[Claims] 1. A nozzle is excited to guide ink to the nozzle, the ink is alternately separated into large-diameter particles and small-diameter particles from the nozzle, and the particles are made to fly toward a recording medium to record these particles. In an ink jet recording apparatus that charges and deflects according to the above, and records by adhering to a predetermined position of a recording medium and recording, the excitation condition of the nozzle is changed over a wide range within the range where small-diameter particles are generated, Nozzle excitation condition optimization main operation setting means for setting optimum excitation conditions capable of reliably generating and charging, and changing the excitation condition within a narrow range near the nozzle excitation condition obtained by the means, Optimizing excitation conditions Examine the fluctuation of the optimum conditions with the passage of time after execution of the main operation and reset the nozzle excitation conditions to the optimum conditions. Image block recording end identifying means for identifying the end of recording of each image block by dividing one screen to be divided into a plurality of image blocks, and executing the nozzle excitation condition optimization main operation prior to starting the recording of one screen, Then, recording is executed, and at least a part of the nozzle excitation condition optimization fine correction operation is executed in response to the information from the image block recording end identifying means, and the recording of the next image block is executed after the operation is completed. However, it is characterized in that a control calculation device is provided for controlling the respective means so as to finish the recording of one screen by alternately repeating the recording of the image block and the fine adjustment operation for optimizing the nozzle excitation condition. Inkjet recording device.