JPH0852918A - Recorder - Google Patents

Abstract

PURPOSE: To prevent the deterioration of a recording grade caused by the deterioration of the sensitivity of a photosensor. CONSTITUTION: A transistor 1607 is turned ON by altering a sensitivity correcting signal from present 'high' to 'low' and currents from both resistors 1608, 1606 are supplied to an LED 1601 to enhance the brightness thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device for detecting the position of a recording head with a slit plate and a photo sensor, and more particularly to a recording device for correcting the sensitivity of the photo sensor.

[0002]

2. Description of the Related Art FIG. 30 is a block diagram showing the relationship between a slit plate and a photo sensor of a conventional recording apparatus. 31 to 32 show a signal processing circuit of the recording apparatus. 30 to 32
In, a photo sensor 3001 includes a light emitting diode (hereinafter, referred to as “LED”) 3101 and a photo transistor 3102, and detects whether light passes through the light receiving window 3002 or is blocked. Slit plate 3 of FIG. 30
In 003, the light shielding portion 3004 and the light transmitting portion 3005 have the same width d.
Therefore, they are arranged continuously. The width of the light receiving window 3002 with respect to the slit plate is also d.

When the light receiving window 3002 completely overlaps the light shielding portion 3004, the phototransistor 31 shown in FIG.
02 is in a state of being turned off because the light of the LED 3101 does not reach it. Therefore, since the base current of the transistor 3103 does not flow out, the transistor 3103 is also turned off, and the output 3105 has the same voltage as the minus side power source through the resistor 3104, and becomes "low" in the binarization circuit.

When the light receiving window 3002 completely overlaps the light transmitting portion 3005, the phototransistor 31 shown in FIG.
02 receives light from the LED 3101. As a result, the phototransistor 3120 is turned on, the collector-emitter is electrically connected, and the current starts flowing into the base of the transistor 3103. The transistor 3103 is also turned on, and the output 3105 has the same voltage as the power source on the positive side, and becomes "high" in the binarization circuit.

When the photosensor 3001 scans the slit plate 3003 in the direction of arrow A as shown in FIG. 30A, the collector waveform 3006 of the phototransistor 3102 and the output 3105 are shown in FIG. 30B. An output waveform 3007 is obtained. In this case, the slit plate 3003
It can be seen that the output waveform 3007 is output corresponding to the positions of the light shielding portion 3004 and the light transmitting portion 3005.

Here, when the photo sensor 3001 is changed to another one, even if the parts are within the same standard, the sensor sensitivities have individual differences, so that it is assumed that a waveform as shown in FIG. 30 (c) is obtained. . The collector waveform 3008 of the phototransistor 3102 is higher than that of the collector waveform 3006 of (b).
The voltage at the light passing part is approaching the positive power supply side. This indicates that the base current of the phototransistor 3102 is small. The cause is the phototransistor 3102.
Is a phenomenon in which the photosensor 3001 has a low sensitivity, such as a low light-receiving sensitivity or a small amount of light emitted from the LED 3101. The output waveform 3009 has a ratio of “high” to “low” that is not 1: 1 and the slit plate 3003 shields light. Part 3004
Therefore, it cannot be said that the slit information of the light transmitting unit 3005 is correctly output.

If the slit information is not correctly output in the recording apparatus that uses the rising and falling edges of the output 3105 as the recording signal, for example, printing unevenness appears in the recording result. Therefore, the output waveform 3009 in FIG. 30C is corrected to the output waveform 3007 in FIG. 30B by adjusting the semi-fixed resistor 3106 in FIG. Further, as shown in FIG. 32, several kinds of resistors such as resistors 3201, 3202, and 3203 are mounted in advance, and cutting adjustment is performed so that the constant becomes an appropriate constant, which is corrected.

[0008]

However, in the above-mentioned conventional example, it is necessary to individually correct the sensitivity of the photosensors one by one, and in the case of mass-producing the recording apparatus, a great deal of labor is required, resulting in a manufacturing cost. It gets expensive.

Further, even if the correction is made at the time of shipping the product, if the user uses it for a long time, the recording quality is deteriorated due to the deterioration of the sensitivity of the photo sensor with time, and in the worst case, there is a defect that the device fails.

Therefore, an object of the present invention is to provide a recording apparatus which is suitable for manufacturing and does not deteriorate the recording quality.

[0011]

In order to achieve such an object, the invention of claim 1 comprises a moving means for mounting and moving a recording means for recording on a recording medium, and a light shielding part. A slit plate composed of a light-transmitting part, a photosensor composed of a light emitting part and a light receiving part, which is attached to the moving means and scans the slit plate, and a signal processing means for binarizing the slit information of the slit plate by the photosensor. And a correction means for correcting the sensitivity of the photosensor, wherein the correction means corrects the sensitivity of the photosensor by comparing the known slit information with the binarized signal by the signal processing means. Is characterized by.

The invention according to claim 2 is characterized in that the correcting means changes the light quantity of the light emitting portion.

According to a third aspect of the present invention, the correction means changes the light receiving sensitivity of the light receiving portion.

According to a fourth aspect of the present invention, in the slit plate, the ratio of the light-shielding portion and the light-transmitting portion is continuous at 1: 1.

The invention of claim 5 is characterized in that the slit plate is changed steplessly from the light shielding portion to the light transmitting portion.

[0016]

According to the first aspect of the present invention, the signal processing means for binarizing the slit information of the slit plate by the photosensor is compared with the known slit information and the binarized signal by the signal processing means to compare the signal of the photosensor. By providing correction means to correct the sensitivity, it is not necessary to make individual adjustments during production, and correction is performed each time the user uses it, so it always works in an optimal state, providing a low-priced and highly reliable product. It becomes possible to do.

According to the second aspect of the invention, the correction means corrects the sensitivity of the photosensor by changing the light amount of the light emitting portion.

According to the third aspect of the invention, the correction means changes the light-receiving sensitivity of the light-receiving portion to correct the photosensitivity of the photosensor.

In the invention of claim 4, the slit plate is one in which the ratio of the light shielding part and the light transmitting part is continuous at 1: 1.

According to the fifth aspect of the invention, the slit plate is a stepless change from the light shielding portion to the light transmitting portion.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

<First Embodiment> (Description of Mechanism) A recording apparatus to which the present invention is applied will be described. 1 is a plan view for explaining the mechanism of a recording apparatus according to the present invention, FIG. 2 is a right side view (a view on arrow A) of FIG. 1, FIG. 3 is a left side view (a view on arrow B), and FIG. 5 is a front view (viewed from the arrow D), and FIG. 6 is a sectional view taken along the line EE.

In FIG. 1, reference numeral 1 is a base frame forming the entire apparatus, and a carriage 3 having a recording head 2 constituting a recording means is mounted on the frame 1 so as to be movable in the directions of arrows P and Q. ing. The recording head 2 uses an inkjet recording system in which ink is ejected from an ink ejection port by applying energy according to a recording signal. Among them, thermal energy is generated as energy used for ejecting ink. As a means for doing so, for example, an electrothermal converter, a laser beam, etc., which causes a change in the state of the ink by this thermal energy is used. This is because according to this method, high density recording and high definition recording can be achieved.

Reference numeral 4 denotes a set lever rotatably mounted around a hole formed in the carriage 3, which is pressed against a flexible cable 6 for connecting the recording head 2 to a drive circuit board (not shown). It is a member for fixing.

The carriage 3 has a base frame 1
It is supported by a slide shaft 5 (see FIGS. 2 and 3) fixed to the carriage 1 and a carriage supporting portion 1c (see FIGS. 5 and 6) of the frame 1, and is slidable in the directions of arrows P and Q in FIG. There is. Then, the carriage 3 enters a single lead groove portion 13b (see FIG. 5 and later-described FIG. 7) formed in the screw 13, which is a rotating body described later, and the rotational movement of the screw 13 in the directions of arrows P and Q in FIG. A protruding pin 3 a (see FIG. 6) for converting into a linear motion is formed integrally with the carriage 3.

A platen 7 has a function as a guide for a recording sheet which is a recording medium. The feed roller 8 for conveying the recording sheet is the base frame 1
The right side plate 10 is rotatably supported by the right side plate 10, and a gear portion 8a is formed at a predetermined position. A rubber ring 9 is attached to the center of the feed roller 8, and a pinch roller 23 is arranged below the rubber ring 9 so as to face the pinch roller 23 by a shaft (not shown) having spring elasticity. Pressure is applied to the rubber ring 9. The recording sheet is inserted between the rubber ring 9 and the pinch roller 23, and is conveyed according to the rotation amount of the feed roller 8.

Reference numeral 15 is a DC motor as a drive source.
Reference numerals 50a and 50b denote clips for fixing the flexible cable 6, respectively. The flexible cable 6 press-fixed to the recording head 2 is fixed by sandwiching it in the carriage 3 with the clip 50a to have a certain slack. It is fixed to the base frame 1 with a clip 50b and led out from the front of the recording device. A slit plate holder 51 holds a slit plate for generating a discharge position detection signal (details will be described later).

FIG. 2 shows a right side view (a view from arrow A) of FIG. 1 from which the above-mentioned right side plate 10 is removed. In FIG. 2, 11 is a main gear which is a first rotating member, and this is a shaft 11a integral with the main gear 11 and a shaft 11b at the other end.
The right side plate 10 and the base frame 1 (FIG. 7 which will be described later), respectively.
It is rotatably supported by receiving it in the hole. 14 is the second
Is a reversing gear that is a rotating member of, and is rotatably supported by a shaft protruding from the base frame 1. Reference numeral 13 denotes a screw, and a gear member 13a which is a third rotating member is integrally formed at the right end portion thereof.

The reversing gear 14 and the screw gear 13a are always in mesh with each other, but the main gear 11 and the reversing gear 14 are in mesh with each other.
Alternatively, the power transmission is intermittently performed with the screw gear 13a by a mechanism described later. 1b is
The carriage 3 is a hole formed in the base frame 1.
The flexure of the flexible cable 6 when it is moved to the right end is prevented from coming into contact with the base frame 1 by letting it escape into the hole 1b.

FIG. 3 is a front view (viewed in the direction of arrow B) of FIG.
FIG. 4 is a rear view (view from the direction of arrow C) of FIG. 1. In FIG. 4, because of the triangular drawing method, the upper part of the recording device is drawn upward in the drawing and the upper part is drawn downward. The first worm gear 21 is press-fitted and fixed to the motor shaft of the drive source motor 15. This first
A disk-shaped encoder slit 21a is integrally formed at the tip of the worm gear 21 and enters the groove of the transmission type photo sensor 55 which is a motor stop signal generator. Reference numeral 53 is a substrate for soldering the motor photosensor 55, which is fixed to the base frame 1 with a small screw. Reference numeral 54 is a lead wire for connecting the board 53 to a circuit board (not shown).

Reference numeral 56a denotes a first wheel gear, which is always in mesh with the first worm gear 21, and its rotation axis is orthogonal to the rotation axis of the first worm gear 21 (perpendicular to the paper surface). There is. Reference numeral 16 denotes a motor mounting plate made of a metal plate, which is fixed to the base frame 1 with a small screw and is bent into an L shape to fix the DC motor 15 with a small screw. Furthermore, the motor mounting plate 1
6 also serves to rotatably hold the shaft 56c of the first wheel gear 56. Reference numeral 20 is a lead wire for connecting a rotating substrate (not shown) and the DC motor 15,
As a result, electric power is supplied to the DC motor 15.

FIG. 5 is a front view (viewed in the direction of arrow D) of FIG.
Reference numeral 52 is a metal plate such as stainless steel having a thickness of about 0.1 to 0.2 mm, which is a slit plate provided with grid-like slits formed by etching or pressing. The slit plate 52 may be a resin film printed with light-shielding paint. 5
Reference numeral 1 denotes a slit plate holder for holding the slit plate 52 with a small screw or the like, which is fixed to the boss 1a of the base frame 1 with a small screw and is fixed together with the slit plate 52. Then, the slit photosensor 59, which will be described later, detects the ejection position detection signal by the slit plate 52.

FIG. 6 is a sectional view taken along line EE in FIG. 56a is the above-mentioned first wheel gear,
The worm gear 21 of is engaged. Further, 56b is a second worm gear, which is a rotary shaft of each
6c, 56d and the first wheel gear 56a are integrally formed. The rotary shaft 56c is supported by being fitted into the hole 16a of the motor mounting plate 16 via the bearing 57, and one rotary shaft 56d is passed through the hole of the bearing portion 1d formed integrally with the base frame 1. The first wheel gear 56a and the second worm gear 56b can be rotated by being supported by.

Reference numeral 11b denotes a second wheel gear integrally formed with the main gear 11, which is rotatable by passing a right side plate 10 at one end and a base frame 1 at the other end through a hole integrally formed with the base frame 1. Becomes Then, the second wheel gear 11b meshes with the second worm gear 56b. Therefore, the driving force of the DC motor 15 is as follows: DC motor 12 → first worm gear 21 → first wheel gear 5
6a → second worm gear 56b → second wheel gear 11b → main gear 11 is transmitted as indicated by an arrow.

Reference numeral 3a is a projecting pin formed integrally with the carriage 3, and enters a lead groove portion 13b (see FIG. 7) into a single line formed on the screw 13 so that the screw 1
The rotational movement of 3 can be converted into a linear movement in the directions of arrows P and Q in FIG. Further, 3c is a hook portion integral with the carriage 3, and is engaged with a carriage support portion 1c integral with the base frame 1. Since the other end of the carriage 3 is supported by the sliding shaft 5, the carriage 3 can move in the vertical direction of FIG. 6 (direction of arrows P and Q in FIG. 1).

Reference numeral 58 is a printed circuit board (PCB).
The slit photo sensor 59 is soldered, and the PCB 58 is fixed to the boss 3c of the carriage 3 with a small screw so that the slit photo sensor 59 is fixed to the carriage 3. The slit photosensor 59 fixed to the carriage 3 detects the movement state of the carriage 3.
This is performed by detecting the slit of the slit plate 52 of the slit plate holder 51 fixed to. The ejection position detection signal detected by the slit photo sensor 59 is
Flexible cable 6 soldered to B58
The branched 6a is sent to the drive circuit board (not shown) through the flexible cable 6 and controlled.

Next, a power transmission system for reciprocating the carriage 3 will be described. FIG. 7 is a perspective view schematically showing a power transmission system related to the reciprocating motion of the carriage 3.
The DC motor 15 always rotates in one direction when energized. As a result, in FIG. 7 as well, as described in FIG.
Motor 15 → first worm gear 21 → first wheel gear 56a → second worm gear 56b (integral structure with first wheel gear 56a) → second wheel gear 11b
→ Main gear 11 (integrated with the second wheel gear 11b)
Power is transmitted through the path. And the main gear 1
1 in the direction of constantly rotating 1 in the direction of arrow J
Has determined the direction of rotation.

The power of the main gear 11, which is constantly driven to rotate in the direction of arrow J in FIG. 7 as described above, is transmitted from the linear main gear 11 to the screw gear 13a by a mechanism described later.
7 is transmitted, the screw 13 rotates in the direction of arrow K in FIG. 7, and the carriage 3 moves in the direction of arrow P at this time.

On the other hand, when the power is transmitted from the main gear 11 to the reversing gear 14, the reversing gear 14 and the screw gear 13a always mesh with each other as described above, so that the reversing gear 14
Rotates in the direction of arrow L in FIG.
Rotates in the direction of arrow M, and at this time, the carriage 3 moves in the direction of arrow Q.
Move in the direction.

Next, the shapes of the main gear 11, the reversing gear 14, and the screw gear 13a will be specifically described with reference to FIGS. 8A and 8B are explanatory views showing the front face portion (a) and the side face portion (b) of the main gear 11, respectively. The main gear 11 faces the reversing gear 14, the screw gear 13a, and the feed roller gear 8a. Are divided into three facing parts.

First, the portion facing the screw gear 13a is
The gear portion 31 and the cam portions 30 and 32 at both ends thereof are provided. The number of teeth of the gear portion 31 is set to 18 teeth in this embodiment, but this value is set to the reversing gear 14 and the screw gear 13.
It is determined by the number of teeth of a and how many times the screw 13 is driven to rotate.

Next, a portion facing the reversing gear 14 is similarly composed of a gear portion 34 and cam portions 33 and 35 at both ends thereof,
It is set to have the same shape as the facing portion of the screw gear 13a, and the difference is that the cams 33 and 35 are provided at the respective end portions, that is, the toothless portion of the reversing gear 14 or the screw gear 13a described later. (40 in FIGS. 9 and 10)
Or 42) is provided at the facing position.
The portion facing the feed roller gear 8a will be described later.

FIG. 9 is an explanatory view showing a side surface portion (a) and a front surface portion (b) of the reversing gear 14, respectively. A full circumference tooth portion 38 having full circumference teeth and a partial tooth missing portion (three teeth) 40 are shown. The toothed portion 39 has a toothed portion 39. As described above, the toothless portion 40 is located at a position facing the cam portions 33 and 35 of the main gear 11. Further, the teeth of the full-circumferential tooth portion 38 and the toothed portion 39 are set so as to be out of phase with each other by half a tooth α in the rotational direction.

FIG. 10 is an explanatory diagram of the screw gear 13a. Note that (a) is a side surface portion thereof, and (b) is an AA cross section portion of the side surface portion (a). Like the reversing gear 14, it is composed of a toothed portion 41 having a partially toothless portion (three teeth) 42. The toothless portion 42 is provided at a position facing the cam portions 32, 31 of the main gear 11.

Next, the specific operation of the main gear 11 will be described with reference to FIG.
This will be described with reference to FIG. Reference numerals (a) to (d) of FIG. 11 are explanatory views in which the movements of the reversing gear facing portion of the main gear 11 and the reversing gear 14 are limited in order to facilitate understanding of the operation.
State (a) shows a state in which the cam portion 35 of the main gear 11 has entered the toothless portion 40 of the reversing gear 14, at which time the rotational force has not been transmitted to the reversing gear 14 yet.
Even if 1 rotates in the direction of arrow J, the reversing gear 14 is stopped. Next, when the main gear 11 further rotates in the direction of arrow J, the tooth portion 34a provided on the main gear 11 meshes with the tooth portion 14a of the reversing gear 14 as shown in the state (b), and the reversing gear 14 is indicated by the arrow L in the figure. Driven to rotate.

In the state (c), the reversing gear 14 is still rotationally driven in the direction of arrow L. As described above, when the teeth of the main gear 11 are set so that the tooth portions 34b are meshed with each other, as shown in (d), the reversing gear 14 makes one revolution, and then the cam portion 33 enters the toothless portion 40 to cause the reversing gear 14 to rotate. Stop and lock the rotation of. The same operation is performed in the mutual transmission operation between the screw gear facing portion of the main gear 11 and the screw gear 13a.

Further, since the toothed portion 38 (see FIG. 9) of the reversing gear 14 and the screw gear 13a are always in mesh with each other, one rotation operation of the reversing gear 14 is performed.
A is transmitted to a, and the screw 13 makes one rotation.

Here, the facing portion of the main gear 11 facing the reversing gear 14 and the facing portion of the screw gear 13a are set in a state where their phases are substantially shifted by 180 ° as shown in FIG. 8 (actually, Is 180 ° as shown in FIG.
As shown in the meshing relationship diagram, the angle θ between the position of the reversing gear 14 and the screw gear 13a to the center of the main gear 11 is
(The phase is further shifted by that amount), and in the state of the portion (b) of FIG. 10, the positional relationship between the facing portion of the screw gear and the screw gear 13a is in the state of the portion (a) of FIG.

However, in FIG. 7, (1) when the main gear 11 rotates 0 ° to 180 °, the reversing gear 14
Rotates once in the direction of arrow L, and the screw gear 13a makes one rotation in the direction of arrow M through the reversing gear 14. Also,
(2) When the main gear 11 rotates 180 ° to 360 °, the screw gear 13a makes one rotation in the direction of arrow K, and the reversing gear 14 moves through the screw gear 13a to the arrow N.
Make one full turn in the direction.

When the state is switched from (1) to (2) and (2) to (1), the cam portions 32 and 35 are accurately aligned with the toothless portions of the reversing gear 14 and the screw gear 13a. When inserted, the cam portions 30 and 33 enter the toothless portions to fix the gears.

(Recording Sheet Conveyance Transmission System) Next, the recording sheet conveyance transmission system will be described. The recording sheet conveying operation is performed by intermittently rotatably driving the gear portion 8a of the feed roller 8 as the tooth portions 36 and 37 integrally formed with the main gear 11 in FIG. The tooth portions 36 and 37 are out of phase with each other by 180 °, and are set by the screw 13 so that the carriage 3 is located in the vicinity of both side portions and in a region where the recording operation of the recording head 2 is affected. There is.

Next, the recording operation in this embodiment will be described. Note that FIG. 13 is a block diagram showing the configuration of the peripheral portion of the recording apparatus according to the present embodiment. The CPU 60, the keyboard 61, the display 62, the power supply unit 63, the motor drive circuit 64, the recording head drive circuit 65, and the recording apparatus 66. ，
The ejection position detection signal processing circuit 67 is configured. As the signal input from the recording device 66 to the CPU 60, the slit photosensor 5 for the ejection position detection signal is used.
The discharge position detection signal processing circuit 6 outputs the discharge position detection signal and the motor stop signal output from the motor photo sensor 55 for detecting the motor stop signal.
A sensitivity correction signal is output from the CPU 60 to 7. DC
When a voltage is applied to the motor 15 to start it, the worm gear 2
1. Encoder slit disk 21a integrally formed with 1
Generates a motor stop signal.

Next, the carriage 3 starts moving in the direction of arrow P from the right end of FIG. 1 by the mutual operation of the reversing gear 14 and the screw gear 13a of the main gear 11. When the carriage 3 starts moving, the slit photo sensor 59 fixed to the carriage 3 causes the slit 52 of the slit plate 52 to move.
When it starts passing through a, an ejection position detection signal corresponding to the slit 52a is generated. This signal is set for each dot row in the dot matrix so as to correspond to a predetermined recording operation.

The CPU 60 receives the ejection position detection signal and selectively outputs a recording signal in synchronization with the ejection position detection signal to perform recording in the direction of arrow P in FIG. When the recording in the P direction is completed, the CPU 60 counts the number of pulses of the motor stop signal and, after N pulses, deenergizes the DC motor 15. At this time, as described above, the recording sheet conveying operation has already been completed, and the carriage 3 stops at the left end of FIG. FIG. 14 shows a timing chart of the above-described arrow P direction recording sequence.

Next, when the motor 15 is started again, the screw 13 reversely rotates due to the above-described reversing mechanism of the screw 13, and the carriage 3 starts moving from the left end of FIG. 1 in the arrow Q direction. A motor stop signal is also generated at the same time when the motor 15 is started. Further, when the slit photo sensor 59 passes through the slit 52a of the slit plate 52, an ejection position detection signal is generated, and in synchronization with this, a C
By selectively outputting the recording signal from the PU 60,
Recording is performed in the direction of arrow Q.

When the recording in the direction of the arrow Q is completed as described above, the CPU 60 counts the number of pulses of the motor stop signal and turns off the power supply to the motor 15 after M pulses. At this time, as described above, the recording sheet conveying operation is also completed, and the carriage 3 stops at the right end portion in FIG. The above-mentioned timing chart of the recording operation sequence in the direction of arrow Q is shown in FIG.
5 shows.

By repeating the above operation,
Recording on the recording sheet is performed. Further, the CPU 60 needs to determine in advance whether the carriage 3 is located at the left end portion or the right end portion in FIG. 1, and as a method thereof, for example, when the system is powered on, or for example, all clear, etc. The DC motor 15 is energized when the specific key is pressed. When the slit photo sensor 59 passes through the wall portion 52b of the slit plate 52, the discharge position detection signal continues to be in the "Low" state X for a certain period of time, and then the carriage 3 moves on the basis of the next passing slit. It is determined that the direction from the right end of FIG. 1 is in the direction of arrow P. Further, when the slit photo sensor 59 passes through the hole 52c of the slit plate 52, the discharge position detection signal is kept in the high state Y for a certain period of time, and then the slit is passed through the slit. Judge that you are heading for.

Hole portion 52c, wall portion 52b, slit 52a
Each of the judgments is made based on whether the state of “high” or “low” continues for a certain time or more, or whether the state of “high” or “low” is switched within a certain time. After determining the direction of arrow P or Q, after passing through the slit, the number of pulses of N and M signals and the motor stop signal are counted, respectively, and the energization of the motor 15 is turned off to end the initial operation. You can

Further, the number of pulses from the end of recording in the directions of the arrows P and Q to the stop of the driving of the DC motor 15 is N and M, respectively, but the number of pulses is basically set to the same value. To do. However, it is possible to make a difference due to a difference in load.

(Sensitivity correction operation in the present embodiment) FIG. 16 is a drawing which best represents the features of the present invention. In FIG. 16, 59 is a slit plate showing the circuit configuration of the ejection position detection signal processing circuit 67 in FIG. A slit photosensor that detects slit information of 52, 1601 is an LED that is a light emitting unit of the slit photosensor 59, 1602 is a phototransistor that is a light receiving unit of the slit photosensor 59, 16
Reference numeral 03 is an output transistor, which is a phototransistor 1602.
When is turned on, a base current flows out to be turned on, and has a function of keeping the output 1605 at substantially the same voltage as the positive power supply (“high” in the binarization circuit). The resistor 1604 has a function of keeping the output 1605 at substantially the same voltage as the negative power supply (“low” in the binarization circuit) when the output transistor 1603 is off. Reference numeral 1606 is a current limiting resistor of the LED 1601, 1607 is a brightness correction PNP transistor of the LED 1601, 1608 is a brightness correction resistor of the LED 1601, and the transistor 1607 is the CPU 6
It is controlled by a sensitivity correction signal which is an output signal of 0, and is turned off when the sensitivity correction signal is "high" and turned on when the sensitivity correction signal is "low". The output 1605 is the CPU 6 as the ejection position detection signal.
Input to 0.

Now, in FIG. 16, the sensitivity correction signal is set to "high", the transistor 1607 is turned off, and the LED
A current limited only by the resistor 1606 is supplied to 1601 to start the motor 15. It is assumed that the carriage 3 is in a recording completed state in the arrow P direction and is moved in the arrow Q direction when the motor 15 is started. The timing chart at this time is as described in FIG. 15, and the details of the ejection position detection signal are as shown in FIG. In FIG. 17, 1701 is the collector voltage waveform of the phototransistor 1602 of FIG. 16, and 1702 is the waveform of the output 1605, that is, the ejection position detection signal waveform. Reference numeral 1703 is a collector voltage of the phototransistor 1602 when the transistor 1603 is switched on / off, that is, a threshold voltage. When the collector voltage 1701 is higher than this voltage 1703, the output waveform 1702 is “low”,
Conversely, when the collector voltage 1701 is low, the output waveform 17
02 becomes “high”.

Reference numeral 1704 shows the recording result when the recording signal is sent to the recording device 66 in synchronization with the rising and falling of the output waveform 1702. Since the width SH of the light-transmitting portion of the slit 52a and the width SL of the light-shielding portion are the same length, originally all the dot widths of the recording result 1704 must be the same, but in FIG. 17, the dot width DH1 is used.
And the dot width DL1 are different. This is because the collector voltage of the phototransistor 1602 is only slightly applied to the threshold voltage 1703 at the light transmitting portion of the slit 52a.

When the dot width DH1 and the dot width DL1 are correctly set to the same width, the sensitivity correction signal is changed from the current "high" to "low", so that the transistor 1607 is changed.
Is turned on and the current from both the resistor 1608 and the resistor 1606 is supplied to the LED 1601.
Increase the brightness of 01. Then, as shown in FIG. 18, the amplitude of the collector voltage 1801 increases and the output waveform 1802 increases.
The “high” and “low” time widths are the same width as TH2 and TL2, that is, the dot widths DH2 and DL2 are also recorded with the same width, and the slit width SH,
Recording is performed in synchronization with SL correctly.

The process of detecting the difference between the dot widths DH1 and DL1 and outputting the sensitivity correction signal will be described with reference to FIG. FIG. 19 shows a processing procedure realized by software in the CPU 60, where the motor 15 of the recording device 66 is activated to stabilize the speed of the carriage 3, that is, immediately before the slit hole 52c in the P direction recording, and in the Q direction recording, the slit. It is executed immediately before the wall portion 52b. By performing this processing only during the initial operation of the recording device 66, the processing load on the CPU 60 during the recording operation can be reduced.

In FIG. 19, the sensitivity correction signal is initialized to "high" in processing 1901, and the rising edge of the ejection position detection signal is detected in processing 1902. When the ejection position detection signal rises, the timer 1 or the like in the CPU 60 starts the time measurement TH in order to detect the "high" time width in the process 1903. After the trailing edge of the ejection position detection signal is detected in process 1904, the clocking TH is stopped in process 1905, and the time width is set to "high".

Immediately thereafter, the timer TL is started in the process 1906, and the rising of the ejection position detection signal is awaited in the process 1907. If the ejection position detection signal rises, the time TL is stopped in processing 1908, and the time width of "low" is set. In processing 1909, the time measurement result TH and the time measurement result TL are compared, and TH
That is, when the "high" time becomes shorter than the TL, that is, the "low" time, the situation shown in FIG. As a result, the waveform shown in FIG. 18 is obtained, and the correction is completed. On the other hand, when the "high" time is equal to or longer than the "low" time, the process 1910 is skipped and the process ends. As described above, the present embodiment shows the correction means when the "high" portion of the ejection position detection signal becomes short. This is a particularly effective means for correcting the sensitivity deterioration of the slit photo sensor 59 due to deterioration over time.

<Second Embodiment> FIG. 20 shows a second embodiment of the present invention.
FIG. 7 is a circuit diagram of a discharge position detection signal processing circuit 67 of the first embodiment. In the figure, reference numeral 2001 denotes a sensitivity adjusting transistor, and resistor 2002 adjusts the current between the emitter and the base of the transistor 1603 together with the resistor 2003 when the transistor 2001 is turned on and off. Now, when the sensitivity correction signal is "high", the transistor 2001 is turned off, no current flows through the resistor 2002, and only the resistor 2003 is effective between the emitter and the base of the transistor 1603. On the contrary, when the sensitivity correction signal is set to "low", the transistor 2001 is turned on, and the resistor 2003 and the resistor 2002 are connected in parallel between the emitter and the base of the transistor 1603.

The condition for turning on the transistor 1603 is that when the sensitivity correction signal is "low", the phototransistor 1602 is a current obtained by adding the current flowing through the resistors 2003 and 2002 and the base current of the transistor 1603.
Light flowing to the collector of the phototransistor 160
Required for base 2. On the other hand, when the sensitivity correction signal is “high”, the base of the phototransistor 1602 needs enough light to flow the current obtained by adding the current flowing only through the resistor 2003 and the base current of the transistor 1603 to the collector of the phototransistor 1602. . Therefore,
In the phototransistor 1602, by setting the sensitivity correction signal to “high”, it is possible to turn on the transistor 1603 with a smaller amount of light than when the sensitivity correction signal is set to “low”, that is, the sensitivity correction signal is set to “high”. The sensitivity of the ejection position detection signal processing circuit 67 can be increased by setting to.

Now, in FIG. 20, the sensitivity correction signal is set to "low", the transistor 2001 is turned on, and the motor 15 is started. It is assumed that the carriage 3 is in a recording completed state in the arrow P direction, and is moved in the arrow Q direction by starting the motor 15. The timing chart at this time is shown in FIG.
The details of the ejection position detection signal are as described in FIG.
It becomes like 1. In FIG. 21, 2101 is a collector voltage waveform of the phototransistor 1602 of FIG.
2102 is the waveform of the output 1605, that is, the ejection position detection signal waveform. 2103 is a collector voltage of the phototransistor 1602 when the transistor 1603 is switched on / off, that is, a threshold voltage. When the collector voltage 2101 is higher than this voltage 2103, the output waveform 1702 is “low”, and conversely the collector voltage 1710 is low.
When 01 is low, the output waveform 2102 is "high".

Reference numeral 2104 shows the recording result when the recording signal is sent to the recording device 66 in synchronization with the rising and falling of the output waveform 2102. Since the width SH of the light-transmitting portion of the slit 52a and the width SL of the light-shielding portion are the same length, originally all the dot widths of the recording result 2104 must be the same, but in FIG. 21, the dot width DH1 is used.
And the dot width DL1 are different. This is because the collector voltage of the phototransistor 1602 is only slightly applied to the threshold voltage 2103 at the light transmitting portion of the slit 52a. When the dot width DH1 and the dot width DL1 are correctly set to the same width, the transistor 2001 is turned off by changing the sensitivity correction signal from the current “low” to “high”, and the ejection position detection signal processing circuit 6
Increase the sensitivity of 7. Then the threshold voltage 2103
However, since the voltage rises up to the threshold voltage 2201 in FIG. 22, the time widths of the “high” and “low” of the output waveform 2202 are the same as TH2 and TL2, that is, the dot widths DH2 and DL2 are also recorded with the same width. As a result, recording is performed in synchronization with the slit widths SH and SL of the slit 52a.

The process of detecting the difference between the dot widths DH1 and DL1 and outputting the sensitivity correction signal will be described with reference to FIG. FIG. 23 shows a processing procedure realized by software in the CPU 60, where the motor 15 of the recording device 66 is activated and the speed of the carriage 3 is stable, that is, immediately before the slit hole portion 52c in the P direction recording, and in the Q direction recording, the slit. It is executed immediately before the wall portion 52b. By performing this processing only during the initial operation of the recording device 66, the processing load on the CPU 60 during the recording operation can be reduced.

In FIG. 23, the process 2301 initializes the sensitivity correction signal to “low”, and the process 1902 detects the rising edge of the ejection position detection signal. When the ejection position detection signal rises, the timer 1 or the like in the CPU 60 starts the time measurement TH in order to detect the "high" time width in the process 1903. After the trailing edge of the ejection position detection signal is detected in process 1904, the clocking TH is stopped in process 1905, and the time width is set to "high".

Immediately after that, the timer TH is started in the process 1906, and the rising of the ejection position detection signal is waited in the process 1907. When the ejection position detection signal rises, the time TH is stopped in process 1908, and the time width of "low" is set. In processing 1909, the time measurement result TH and the time measurement result TL are compared, and TH
That is, when the time of "high" becomes shorter than the time of TL, that is, "low", the situation is as shown in FIG. 21, and therefore the processing 2302 sets the sensitivity correction signal to "high" and ends. As a result, the waveform shown in FIG. 22 is obtained, and the correction is completed. On the contrary, when the "high" time is equal to or longer than the "low" time, the process 2302 is not performed and the process is ended. As described above, the present embodiment shows the correction means when the "high" portion of the ejection position detection signal becomes short.

<Third Embodiment> FIGS. 24 to 25 show a third embodiment of the present invention. The ejection position detection signal processing circuit 67 is shown in FIG. 16, and the sensitivity correction signal control processing procedure is shown in FIG.
It is as follows. In this embodiment, the carriage 3 is on the right side of FIG.
Wall 52 for determining which of the left ends is located
The triangular hole 52d is provided in b, and the triangular hole 52d allows the slit photosensor 59 to continuously change from the light-shielding portion to the light-transmitting portion.

Now, immediately before the carriage 3 moves in the direction of the arrow Q to complete the initial operation or the recording operation,
When counting the motor stop signal for stopping the motor 15, the process shown in FIG. 25 is performed. Processing 2 in FIG.
At 501, the sensitivity correction signal of the ejection position detection signal processing circuit 67 is initialized to "low" in advance. The end of the slit 52a is detected in processing 2502 and processing 2503, and the number of pulses of the motor stop signal is counted in processing 2504 and processing 2505. This is a portion where the discharge position detection signal waveform 2401 in FIG. 24A continues to be “low” after the slit 52a is detected, and where the collector voltage waveform 2402 of the phototransistor 1602 changes gently. Yes, the number of pulses to be counted is the portion indicated by the range MP1 of the motor stop signal 2405. This is because the light quantity of the LED 1601 is changed steplessly by the triangular hole portion 52d, and the threshold voltage 2
The slit photo sensor 59 is provided on condition that 403 is constant.
Is a means for converting the sensitivity of to the number of pulses of the motor stop signal. The number of measurement pulses thus obtained is determined in processing 2506. The optimum number of pulses of the motor stop signal is shown in FIG.
(B), the number of detection pulses in the triangular hole 52d (motor in range MP2 when the “high” / “low” ratio of the portion corresponding to the slit 52a of the ejection position detection signal 2406 is 1: 1 Number of pulses of stop signal 2408)
Is. If it is determined in processing 2506 that the number of measured pulses is greater than the optimum number of pulses, processing 2507 sets the sensitivity correction signal to “low” to increase the brightness of the LED 1601,
The waveform is set so that it has a normal waveform as shown in part (b).

<Fourth Embodiment> FIG. 26 shows a fourth embodiment of the present invention.
And the slit plate 52 in the third embodiment.
Is printed on the transparent resin plate, and the slit 52 for light
a is provided. Reference numeral 52e denotes a blurring portion which is continuously provided on the wall portion 52b and which is printed so as to continuously change from the light shielding portion to the light transmitting portion. The discharge position detection signal of the slit photosensor 59 passing through the blurring portion 52e is similar to that when passing through the triangular hole portion 52d of FIG. 24, and the sensitivity correction can be performed by the processing of FIG.

By changing the slit plate from a metal plate to a resin plate, complicated steps such as etching become unnecessary,
Since it can be manufactured by printing, it can be mass-produced at low cost.

<Fifth Embodiment> FIG. 27 shows a fifth embodiment of the present invention.
This is an example of the discharge position detection signal processing circuit 67 in the first example. 2 in the figure
701 is a comparator, 2702 is “UP”, “DOW”
By inputting the N ”signal, the numerical value is incremented,
An up / down counter that counts down, and 2703 is a D / A converter that outputs an analog voltage corresponding to the numerical value from the up / down counter. The sensitivity correction signal is composed of two signals, "UP" and "DOWN", and when the signal comes to the sensitivity correction signal "UP", the up / down counter 270
2 counts up, and the output voltage of the D / A converter 2703 increases. On the contrary, when a signal comes to the sensitivity correction signal "DOWN", the output voltage of the D / A converter 2703 drops. Further, the comparator 2701 compares the plus input and the minus input, and if the voltage of the plus input is high, the output 1605 is “high”, and if the voltage of the minus input is high, the output 1605 is “low”. When the output signal of the slit photosensor 59 is connected to the minus input of the comparator 2701 and the output of the D / A converter is connected to the plus input, when the output amplitude of the slit photosensor 59 is binarized to the output 1605. Threshold voltage.

Next, the procedure of sensitivity correction will be described with reference to FIG. The count of the up / down counter is set appropriately beforehand. Next, the sensitivity correction processing is started, and processing 19
From 02 to processing 1908, the time of “high” and “low” of the ejection position detection signal is measured, and then, in processing 1909, the time count TH
And time TL are compared, and if time TL is longer, process 28
At 01, the sensitivity correction signal “UP” is output to increase the output voltage of the D / A converter, that is, the threshold voltage. On the contrary, if the measured time TH is longer or equal, processing 280
At 2, the sensitivity correction signal "DOWN" is output to lower the threshold voltage. When the measured time TH and the measured time TL are equal to each other, the sensitivity correction is not necessary and the process ends. The waveform at this time is shown in FIG. In the figure, a waveform 2901 is a collector voltage of the phototransistor 1602, a waveform 2902 is an initial threshold voltage, and a waveform 2903 is an ejection position detection signal waveform at the initial threshold voltage 2902. At this time, the “high” time TH1 and “low” The time TL1 is longer than the time TL1 of FIG.
Processing 2801 of 8 is executed, and the sensitivity correction signal “UP” is output. Then, the threshold voltage rises and waveform 2
As indicated by 904, the ejection position detection signal after the voltage rise changes to the waveform 2905. After the change, they become equal as can be seen from the “high” time TH3 and the “low” time TL3, and the sensitivity correction is completed.

In the present embodiment, since fine sensitivity correction can be realized, highly accurate recording can be performed.

Further, in each of the above-mentioned embodiments, the case of the ink jet recording system as the recording means has been described, but the bubbles generated by heating the electrothermal converter in accordance with the recording signal and heating beyond the film boiling by the electrothermal converter. It is more preferable that the recording is performed by ejecting the ink from the ejection port according to the growth of the ink.

Regarding the typical structure and principle thereof, for example, the specifications of US Pat. Nos. 4,723,129 and 47407.
What is done using the basic principles disclosed in the '96 patent is preferred. This method can be applied to both the so-called on-demand type and continuous type, but in the case of the on-demand type in particular, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal to the electrothermal converter, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling, thermal energy is generated in the electrothermal converter, and This is effective because it causes film boiling on the heat-acting surface, and as a result, it is possible to form bubbles in the liquid that correspond one-to-one to this drive signal. By the growth and contraction of the bubbles, the liquid is discharged through the ejection openings. It is more preferable that the driving signal for ejecting and forming at least one droplet has a pulse shape, because the bubble is appropriately grown and contracted immediately and particularly excellent ejection of the liquid can be achieved.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable.

If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise of the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, U.S. Pat. Nos. 4,558,333 and 4,445,960 which disclose a configuration in which a heat acting portion is arranged in a bending region.
The configuration using the specification No. 0 is also included in the present invention.

Further, Japanese Patent Application Laid-Open No. 59-123670 discloses a structure in which a common slit is used as a discharge portion of a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The effect of the present invention is effective even if the configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration in which the discharge portion is associated with the discharge portion, is effective. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

In addition, even in the case of the serial type described above, when it is mounted on the recording head fixed to the carriage or the carriage, it is possible to electrically connect to the apparatus main body and supply the ink from the apparatus main body. A replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself may be used.

Further, it is preferable to add a recovery means for the recording head, a preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. Specific examples thereof include capping means, cleaning means, pressurizing or suctioning means for the recording head, preheating means by electrothermal conversion type or other heating element or combination thereof, and recording. It is also effective to perform a stable recording by performing a preliminary discharge mode in which another discharge is performed.

Regarding the type or number of recording heads mounted on the carriage, for example, only one recording head is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. It may be provided in a plural number. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be any of a plurality of combinations that integrally configure the recording head, but different colors of multiple colors or mixed colors It is also applicable to a device having at least one of full color.

In addition, although the ink is described as a liquid in the above-described embodiments, it is an ink which is solidified at room temperature or lower and softens or liquefies at room temperature, or in the ink jet recording system. Ink itself 3
In general, the temperature is controlled within the range of 0 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range. Good. In addition, it is possible to prevent the temperature rise due to thermal energy from being positively used as the energy for changing the state of the ink from the solid state to the liquid state, or to use ink that solidifies when left standing for the purpose of preventing ink evaporation. In any case, the ink is liquefied by applying heat energy according to the recording signal,
The present invention is also applicable to the case of using an ink that has the property of being liquefied only by thermal energy, such as one that ejects liquid ink or one that has already started to solidify when it reaches a recording sheet.

The ink in such a case is described in JP-A-54-
No. 56847 or Japanese Patent Application Laid-Open No. 60-71260, the porous sheet recesses or through holes are held in a liquid or solid state so as to face the electrothermal converter. Is also good. The most effective one for each of the above-mentioned inks is the one for practical use of the above-mentioned film boiling method.

Further, as the form of the above-mentioned ink jet recording device, in addition to a form used as an image output terminal of an information processing device such as a computer, a form of a copying device combined with a reader or the like, and a form of a facsimile device having a transmission / reception function. It is something to take.

Further, the recording means is not necessarily limited to the above-mentioned ink jet recording system, and various recording systems such as a wire dot recording system and a thermal recording system can be used.

[0094]

As described above, by providing the means for correcting the sensitivity of the photosensor, even if there is a variation in the sensitivity of each photosensor or a decrease in sensitivity due to deterioration over time, adjustment shipment is performed at the time of production. In addition, it is possible to always maintain a high-quality recording state while the consumer is using it, and there is an effect that cost reduction and quality improvement can be realized at the same time.

[Brief description of drawings]

FIG. 1 is a plan view showing a mechanism of a recording apparatus according to an embodiment of the present invention.

FIG. 2 is a view on arrow A in FIG.

FIG. 3 is a view on arrow B of FIG.

FIG. 4 is a view on arrow C of FIG.

5 is a view on arrow D in FIG. 1. FIG.

6 is a cross-sectional view taken along line EE of FIG.

FIG. 7 is a perspective view of a carriage drive system.

FIG. 8 is a structural diagram of a main gear.

FIG. 9 is a structural diagram of a reversing gear.

FIG. 10 is a structural diagram of a screw gear.

FIG. 11 is an operation explanatory view of a main gear.

FIG. 12 is an explanatory diagram showing a meshing relationship between a main gear, a screw gear, and a reversing gear.

FIG. 13 is a block diagram showing a configuration of a peripheral portion of a recording device.

FIG. 14 is a sequence timing chart showing a unidirectional recording operation.

FIG. 15 is a sequence timing chart showing another-direction recording operation.

FIG. 16 is a circuit diagram showing a configuration of an ejection position detection signal processing circuit according to the first embodiment.

FIG. 17 is a waveform diagram showing the slit plate and the pre-correction waveform of the first embodiment.

FIG. 18 is a waveform diagram showing a slit plate and a corrected waveform according to the first embodiment.

FIG. 19 is a flowchart illustrating a correction processing procedure according to the first embodiment.

FIG. 20 is a circuit diagram showing a configuration of an ejection position detection signal processing circuit according to a second embodiment.

FIG. 21 is a waveform diagram showing a slit plate and a pre-correction waveform according to the second embodiment.

FIG. 22 is a waveform diagram showing a slit plate and a corrected waveform according to the second embodiment.

FIG. 23 is a flowchart illustrating a correction processing procedure according to the second embodiment.

FIG. 24 is an explanatory diagram showing a slit plate and a waveform according to a third embodiment.

FIG. 25 is a flowchart illustrating a correction processing procedure according to the third embodiment.

FIG. 26 is a schematic structural view showing a slit plate of Example 4.

FIG. 27 is a circuit diagram showing a configuration of an ejection position detection signal processing circuit according to a fifth embodiment.

FIG. 28 is a flowchart illustrating a correction processing procedure according to the fifth embodiment.

FIG. 29 is an explanatory diagram showing a slit plate and a waveform according to the fifth embodiment.

FIG. 30 is an explanatory view showing a slit plate and a waveform of a conventional example.

FIG. 31 is a circuit diagram showing a configuration of a conventional waveform shaping circuit.

FIG. 32 is a circuit diagram showing a configuration of a conventional waveform shaping circuit.

[Explanation of symbols]

 1 Base Frame 2 Recording Head 3 Carriage 5 Sliding Shaft 6 Flexible Cable 7 Platen 8 Feed Roller 11 Main Gear 11b Second Wheel Gear 13 Screw 13a Screw Gear 14 Reversing Gear 15 DC Motor 21 Worm Gear 21a Encoder Slit Disk 52 Slit Plate 52a Slit 52b Wall part 52c Hole part 52d Triangular hole part 52e Blurred part 55 Motor photo sensor 59 Slit photo sensor 60 CPU 64 Motor drive circuit 65 Recording head drive circuit 66 Recording device 67 Discharge position detection signal processing circuit 1601 LED 1602 Photo transistor 1603 Output transistor 1605 Output (ejection position detection signal) 1606 LED current limiting resistor 1701 Phototransistor collector voltage 1702 Ejection Position detection signal waveform 1703 Threshold voltage 1704 Recording dot 2001 Sensitivity adjustment transistor 2002 Sensitivity adjustment resistor 2405 Motor stop signal waveform 2701 Comparator 2702 Up / down counter 2703 D / A converter 3001 Photo sensor 3002 Light receiving window 3003 Slit plate 3004 Light shielding part 3005 Light passing part 3006 Collector waveform of phototransistor 3007 Output waveform 3101 LED 3102 Phototransistor 3103 Transistor 3105 Output 3106 Semi-fixed resistance

Claims (5)

[Claims] 1. A moving means for mounting and moving a recording means for recording on a recording medium, a slit plate composed of a light shielding part and a light transmitting part, and a slit plate attached to the moving means for scanning the slit plate. A photo sensor including a light emitting unit and a light receiving unit; a signal processing unit that binarizes the slit information of the slit plate by the photo sensor; and a correction unit that corrects the sensitivity of the photo sensor,
The recording apparatus, wherein the correction means corrects the sensitivity of the photosensor by comparing the known slit information with a binarized signal obtained by the signal processing means. 2. The recording apparatus according to claim 1, wherein the correction unit changes the light amount of the light emitting unit. 3. The recording apparatus according to claim 1, wherein the correction unit changes the light receiving sensitivity of the light receiving unit. 4. The recording apparatus according to claim 1, wherein the slit plate is continuous with a ratio of the light shielding portion and the light transmitting portion of 1: 1. 5. The recording apparatus according to claim 1, wherein the slit plate is steplessly changed from the light shielding portion to the light transmitting portion.