JPH0796300B2 - Printer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a small printer used for a desktop calculator, a measuring instrument, a data terminal, or the like.

[Prior Art] A conventional type belt printer is disclosed in, for example, SAIKAI Sho 59-1669.
As shown in No. 54, it has been known that only one space type character is used in the symbol type group which is not used for printing.

Further, as disclosed in Japanese Patent Laid-Open No. 57-64555, the structure of the type belt is divided into a blank type group which is a space type which is not used at one time and a type group which is used for printing.

[Problems to be Solved by the Invention] However, in the above-described conventional technology, the former has only one space print when an attempt is made to print with a large number of spaces between numbers or symbols and numbers for easy viewing. Therefore, the next space cannot be selected, and as a result, the printing speed is slow.

The latter is a printer that applies ink to the print type with an ink roller, and when the ink roller presses against a space with no print type, the load on the ink roller is reduced and the load on the motor that drives the belt is also reduced. Therefore, as the motor rotation speed increases, the fluctuation of the detected pulse is large and chattering or detection error frequently occurs, which causes the reliability of the printer to be reduced.

An object of the present invention is to solve the above problems, to increase the printing speed of a printer having a large space and rich expressiveness to improve its function, and further to reduce the speed fluctuation of the printing belt to improve the reliability of the printer. It is in.

[Means for Solving the Problems] In order to solve the above problems, the printer according to the present invention includes a belt driving unit that transmits the rotation of a motor that is a driving source to a type belt, and a detection vehicle that rotates in synchronization with the type belt. Equipped with a detector that outputs a signal corresponding to the print characters, and a rotatable ink roller that presses the print characters and applies ink to the print characters.The layout of the print characters on the print belt is a space not used for printing. Is used for printing, at least two or more of them are arranged differently from each other.

[Operation] According to the above configuration of the present invention, since the space characters are arranged alternately, the fluctuation of the load of the ink roller applied to the motor can be reduced, so that the motor speed can be stabilized.

[Embodiment] Next, an embodiment of the present invention will be described.

<Schematic Mechanism> FIG. 1 is an exploded perspective view of the printer, FIG. 2 is a schematic configuration diagram of the printer, and FIG. 3 is a sectional view of a switching mechanism section. FIG. 4 is a schematic side sectional view. The drive pulley 9 and the driven pulley 19 are arranged at a predetermined interval, and an endless type belt 14 is stretched between them. The driven pulley 19 is rotatably fitted to the frame 1. Reference numeral 2 denotes a motor, to which a bevel gear motor gear 3 is attached. Reduction gear 4
Has a bevel gear that meshes with the motor gear 3 and a spur gear that meshes with the transmission gear 5 and is smaller than the outer diameter of the transmission gear 5.
The selection claw 7 has a structure capable of engaging with the drive pulley 9 and the print switching gear 10, and when engaged with the print switching gear 10, does not engage with the drive pulley 9 but engages with the drive pulley 9. The mechanism is such that it does not engage with the print switching gear 10 when it is operating (details will be described later). In addition, the selection claw 7 is rotatably attached to the frame 1, and a moment is applied by the coil spring 8 in the arrow L direction during standby. Further, it is engaged with the suction plate 33 of the electromagnet 6. The sun gear 22 has a gear meshing with the transmission gear 5 and a gear meshing with a planetary gear 23 rotatably mounted on the drive pulley 9, and is rotatably mounted on the frame 1. The detection wheel 24 is fixed to the drive pulley 9 and further meshes with the gear of an R detection cam 25 rotatably attached to the frame 1, and is fixed to the detection cover 27 and is a detection brush 26 made of a conductive material such as nickel silver. Being pressed against. Detection car
A circuit including a conductive portion and a non-conductive portion is formed on the surface of 24 that contacts the detection brush 26. Printing drum 12 is a hammer
It has a print claw portion 12a that pushes out 13 and is rotated by a worm 11 that is engaged with the print switching gear 10 and is rotatably attached to the frame 1. A feed roller 29 is fitted in the paper feed gear 28, and the paper feed gear 28 can mesh with the paper feed drive gear 12b of the print drum 12.
The push roller 18 is pressed against the feed roller 29 by the load of elastic deformation of the push shaft 21. The ink roller 20 is rotatably attached to the frame 1 and is in pressure contact with the type belt 14. The frame 1 also serves as a paper guide.

Next, the type belt of the embodiment will be described.

<Structure of type belt> This will be described with reference to FIGS. 15 and 16. Type belt 14 is number 15
As shown in the figure, it has an endless shape, and a large number of type parts 14a are individually provided in a predetermined pit on the outer peripheral side along the circumferential direction, and a large number of type parts 14a are provided on the inner peripheral side at a predetermined pitch along the circumferential direction. The belt tooth portion 14b is provided. Individual print part 14a
The belt tooth portion 14b and the belt tooth portion 14b are paired with each other.
4a and the adjacent type part 14a, the belt tooth part 14b and the adjacent belt tooth part 14
A thin connecting portion 14c is connected to b. These type belts 14 are formed of a stretchable elastic material such as rubber. The type belt 14 is divided into a large number of positions at one position. The symbol type characters such as "+" and "-" and the arrangement of the character numbers such as "0", "1" ... "9" in each group are arranged in the same group. Type belt as one of the embodiments
14 positions are 64 positions (1 position is 1 character) and are divided into two groups, I group and II group, and the arrangement of each is shown in FIG. Space from 0 position to 20 positions for each one, odd numbered digits from 1st position to 21st position, symbol 22th position to 31st position are grouped by number type etc. group II and group II are the same arrangement as group I There is. The space does not have a print part 14a, and the other parts have the same shape. As described in <Schematic Configuration>, the type belt 14 is wound around the drive pulley 9 and the heavy driven pulley 19, and the drive pulley 9 has a belt tooth portion.
There are 16 meshing grooves with 14b, and they are rotated by meshing with each belt tooth portion 14b. Next, the detection of the timing pulse will be described with reference to FIGS.

<Detection of Timing Pulse> Four detection brushes 26 made of a conductive material such as nickel silver are pressed against the detection wheel fixed to the drive pulley 9. T brush 26T and t brush are on the trace of TP pattern 24a of the conductive part.
Two 26t are pressed. The number of divisions of the TP pattern 24a is the same as the number of divisions of the drive pulley 9, and is divided into 16 which is an integer fraction of the character position of the character belt 14. T brush 26
When the t brush 26t is in pressure contact with the TP pattern 24a, the t brush 26t is on the non-conductive portion 24b, and when the t brush 26T is in pressure contact with the TP pattern 24a, the T brush 26T is on the non conductive portion 24b. T brush 26T and t brush 26t are installed. The R brush 26R is in pressure contact with the locus of the R pattern 24r. Detection car
24 and the R detection cam 25 mesh with each other, and one rotation of the detection wheel 24 causes the R detection cam 25 to rotate 2.5 times. The R detection cam 25 is made of a non-conductive material, and the disc portion 25a is interposed between the detection wheel 24 and the R brush 26R.
The continuity between 26R and R pattern 24r is cut off. When the detection wheel 24 is rotated once while the R brush 26R and the R pattern 24r are in contact with each other as shown in FIG. 5, the R detection cam 25 rotates 2.52 and the R brush 26R can contact the R pattern 24a by the disc portion 25a. Absent. When the detection wheel 24 makes one more rotation, a total of two rotations, the R inspection cam
The 25 rotates a total of 5 times and returns to the state of FIG. Detection car 24 is 16
Since it was divided, the R brush comes into contact with the R pattern once at 16 × 2 = 32 32 positions. Common brush 26c
A + potential common to the R pattern 24r and the TP pattern 24a is applied to the. The waveforms of the detected T pulse and t pulse are the vibration of the T brush 26T, the t brush 26t, the T brush 26T and the brush 26t.
Chattering is likely to occur due to contact resistance between the TP pattern 24a and the TP pattern 24a. Therefore, a countermeasure method is adopted in which the rising edge of the leading edge 35a of the pulse 35 is recognized and the waveform is corrected to the rising edge and the falling edge to perform control by waveform shaping. T brush 26
On the drive circuit side of the printer, the shaping waveform rises at the leading edge 35a of the rising edge of the T pulse of the potential difference between T and the common brush 26c, and falls at the leading edge 35a of the t pulse rising due to the t brush 26t and the common brush 26c. Control is performed by this waveform shaping. TP0 the shaped waveform where the R pulse is rising
And the type position of the type belt 14 at the position of the lowest digit
31 (or 63) is opposed to drive the type belt 14 to drive pulley 9
And the driven pulley 19. The electromagnet energization waveform is controlled by the rising edge of the leading edge 35c of the shaped waveform. Shaped corrugated leading edge 3
The current is energized to the electromagnet at the rising edge of 5c and the next waveform is the leading edge of the waveform 35c.
Shut off at the rising edge of. The case of continuous printing will be described with reference to FIG.

As shown in Fig. 17 (a), "Space" is printed in the first digit, "%" is printed in the second digit, "*" is printed in the third digit, and "◇" is printed in the fourth digit. The fastest possible mode is to energize the electromagnet at the leading edge of TP0, shut off at the leading edge of TP1 and select'space 'for the first digit, then apply electricity to the electromagnet again from TP2 detected and then at the second digit. You can print '%'. As described above, the printing speed becomes maximum when the selective printing is performed every two pulses.

If you want to print the desired characters for the desired number of digits and then select the space, select the space with TPO and then select TP3 and then TP6TP9 ... every 3 pulses as shown in Fig. 17 (b). Spaces at positions “0”, “2”, “4”, “6” ... Are selected.

Since the present embodiment is a cycle machine that selectively prints one digit to the most significant digit for printing one digit and performs a paper feeding process, if the desired type is, for example, seven digits, space characters are printed from eight digits to the most significant digit. Need to print selectively. When used in a calculator, it does not print up to the most significant digit, and printing speed can be increased by arranging a lot of space type characters on the type belt.

Next, the type selection mechanism will be described.

<Type selection mechanism> Explanation will be given with reference to FIGS. 1 to 3, 6, and 19. The motor 2 fixed to the injection-molded frame 1 by utilizing the elasticity of the frame 1 rotates in the arrow A direction. The reduction gear 4 rotates in the arrow B direction and the transmission gear 5 rotates in the arrow C direction via the motor gear 3. The sun gear 22 rotates in the direction of arrow D and the planetary gear 23 rotates in the direction of arrow E in response to the rotation of the transmission gear 5. FIG. 6 (a) is an explanatory view of the operating mechanism in which the electromagnet is not energized. The planetary gear 23 rotating in the direction of the arrow E is printed from the inner teeth 10a of the print switching gear 10 to the print switching gear 1
Although 0 is applied with a rotational force in the direction of arrow H, the claw 7a of the selection claw 7 engages with the opening 10b of the print switching gear 10 to prevent rotation of the print switching gear 10. As a result, the planetary gear 23 revolves in the arrow F direction along the internal teeth 10b, and the drive pulley 9 rotates in the arrow F direction. The drive pulley 9 has the groove 9b that meshes with the belt tooth portion 14b of the type belt 14 as described in the above-mentioned <Structure of type belt>, and the type belt 14 is reliably rotated in the arrow G direction without slippage. The driven pulley 19 serves to reduce the load so that the type belt 14 can be smoothly rotated, and to cause the type belt 14 to run parallel to the platen 17. Type belt
When the cost reduction is emphasized rather than the rotational load of 14, the driven pulley 19 is provided with a cylindrical or semi-cylindrical shape on the injection-molded frame 1 in order to reduce the parts cost and the assembly cost.
Can be abolished. When the drive pulley 9 rotates, the detection brush is detected as described in <Detection of timing pulse>.
26 T brush 26T, t brush 26t, common brush 26c, R brush
Detect the pulse from 26R and print on the desired printing part 14
When the desired character type portion 14a reaches, the energizing signal is sent to the electromagnet 6. FIG. 6B is an explanatory diagram of the differential mechanism when the electromagnetic color 6 is energized. When the electromagnetic color 6 is energized, the suction plate 33
Generates a force in the direction of arrow K. The selection claw 7 applies a force to the action portion 7c that is in contact with the suction plate 33, and a moment is applied in the arrow M direction. From the moment of the coil spring 8 in the direction of arrow L and the moment of the friction load applied to the claw portion 7a, the suction plate 33
When the moment in the direction of arrow M given by is large, the selection claw 7 rotates in the direction of arrow M. The locking portion 7b of the selection pawl 7 jumps into the locus of the ratchet 9a of the drive pulley 9 rotating in the direction of arrow F, collides with the ratchet end surface 9b, and the drive pulley 9 stops rotating. The planetary gear 23 rotatably attached to the drive pulley 9 stops the revolution revolving around the sun gear 22 and changes to a rotation motion rotating in the arrow E direction. On the other hand, the print switching gear 10 is rotatable because the selection claw 7 rotates in the direction of the arrow M and the claw 7a is disengaged from the opening 10b. The print switching gear 10 receives the rotation of the planetary gear 23, which is rotating in the direction of arrow E, whose revolution is stopped, on its internal teeth 10a, and rotates in the direction of arrow H. The claw portion 7a of the selection claw 7 disengaged from the opening 10b presses the cam outer peripheral portion 10c. Worm 1 engaged with gear 10d provided on the outer periphery of print switching gear 10.
The worm 11 rotates in the direction of arrow I by the gear 11b of 1. The number of teeth z10 of the gear 10d of the print switching gear 10 is set to an integral multiple of the number of teeth z11 of the gear 11b of the worm 11, and the number of openings 10b of the print switching gear 10 is set to z10 / z11. This example is z10
= 48 and z11 = 12 are set. When the worm 11 makes one revolution, the opening 10b comes. The claw portion 7a of the selection claw 7 which has a moment in the arrow L direction due to the coil spring 8 is in pressure contact with the cam outer peripheral portion 10c of the rotating print switching gear 10, and when the next opening 10b comes, it is in the arrow L direction. To engage with the opening 10b. The engaging portion 7b is disengaged from the drive pulley 9 with the ratchet 9a, and the suction plate 33 is moved in the direction of arrow W. The print switching gear 10 stops rotating, the planetary gear 23 starts to revolve in the arrow F direction, and the drive pulley 9 rotates in the arrow F direction. Type belt 14
Starts to rotate and returns to the standby state in which an energization signal to the next electromagnet 6 is received. Next, the printing mechanism will be described. Next, the printing mechanism will be described.

<Printing mechanism> FIG. 4, FIG. 7 to FIG. 9, FIG. 12 to FIG. 14, and FIG.
It will be described with reference to FIG. FIG. 14 is a perspective view of the print drum 12, FIG. 13 is a perspective view of the unit of the hammer 13, FIG. 7 is a sectional view of a standby state before the start of printing of the first digit, and FIG. 8 is printing of the first digit. Cross-sectional view of the process, Fig. 9 is a cross-sectional view of the stand-by state after printing the first digit, Fig. 12 is the state of the home position brush before standby before printing the first digit, and Fig. 12 is after the first-digit printing. The state figure of the home position brush of is shown. The hammer 13 is composed of a pressing portion 13e, an elastic portion 13c, and a connecting portion 13d, and is integrally formed of plastic or the elastic portion 13c.
Only c is insert molded with metal spring material. The number of hammers 13 is the number of print digits, and they are connected by connecting portions 13d, and the connecting portions 13d are fixed to the frame 1. First digit printing will be described. A home position cam 12d provided on the side surface of the print drum 12 pushes down a home position brush 26H which is elastically deformed by a road electric material such as nickel silver in the direction of the arrow X to bring it into contact with the common brush 26a to generate a print drum home position signal. By confirming this signal, it is confirmed that the print drum 12 is at the first digit print standby position. When the desired type portion 14a of the type belt 14 arrives at the first digit, an energizing signal is sent to the electromagnet 6. As described above in the <type selection mechanism>, the worm 11 is rotated by the rotation of the print switching gear 10. The worm tooth 11a is composed of a tooth tip 11e, a circumferential projection 11c, and a spiral projection 11d. FIG. 19 is a diagram showing the relationship between the worm tooth 11a and the pin 12c in the standby state. The solid line is a development view of the worm tooth 11a.
The alternate long and short dash line is a perspective view of the worm tooth 11a. During standby, the circumferential ridge 11c of the worm tooth 11a is the pin 12c of the printing drum 12.
It is located between the pins 12c in the movement locus of and controls the free rotation of the printing drum 12. The gap s3 with the lower pin 12c is made larger than the gap s1 between the circumferential protrusion 11c and the lower pin 12c so that the tooth tip 11e of the worm tooth 11a does not collide between the pins 12c. A gap s3 is provided between the portion 11e and the upper pin 12c. When the worm 11 rotates, the tooth tip 11e enters the locus of the center 12c before the cylindrical protrusion 11c controlling the rotation of the print drum 12 separates from between the pins 12c. Circumferential ridge 11c is pin 12c
Away from the locus, and then the pin 12c is the upper surface of the spiral ridge 11d.
The printing drum 12 is lifted by 11f and rotates in the direction of the arrow. Print claws installed on the circumference of the print drum 12.
12a pushes the back surface 13b of the pressing portion 13e of the hammer 13 in the direction of arrow U, presses the belt tooth portion 14b of the type belt 14 with the pressing surface 13a stopped, and presses the type portion 14a against the printing paper 16. When the print drum 12 further rotates in the direction of the arrow ○, the back surface 13b of the pressing surface 13e and the print claw portion 12a sliding on the back surface 13b are disengaged, and the elasticity of the elastic portion 13c of the hammer 13 causes the hammer pressing portion 13e to move. It moves in the direction of arrow V and is returned to the standby position. On the other hand, the print drum 1 in which the home position brush 26H made of an elastic body is elastically deformed and brought into contact with the common brush 26a
The second home position cam 12d rotates in the direction of the arrow ○ and is disengaged from the home position brush 26H. The disengaged home position brush 26H moves in the direction of the arrow Y and separates from the common brush 26a. The home position signal obtained from the home position brush 26H and the common brush 26a is 1
Shut off the middle of printing the digit (see Fig. 18). <
The character selection and the printing operation described above are repeated from the second digit to the most significant digit. If printing is not necessary, space type printing is selected from the type position on the type belt 14. FIG. 21 is an enlarged view of the printed state. 20th
The drawing is a partial detailed view for explaining the printing position and the position of the comb teeth. The comb teeth 15 are provided on the platen 1 which also serves as a part of a guide so that the printing paper 16 faces the hammer 13. The comb tooth 15 has a printing area 34 which is an area through which the character portion 14a passes during printing.
The length from the lower part to the vicinity of the upper end 34a of the printing area 34 is injection-molded so as to project from the frame 1. Comb teeth 15
Are arranged between the print area 34 and the adjacent print area.
This will be explained with reference to FIG. The alternate long and short dash line indicates the standby position.
The hammer 13 held on each print digit is serially pushed out by the rotation of the print drum 12, and the hammer 13 moves in the direction of the arrow U to press the print portion 14a against the print paper 16 via the print belt tooth portion 14b. Since the ink is applied to the character portion 14a by the ink roller 20, the ink is transferred to the paper character paper 16.
The distance s between the comb teeth 15 and the printing paper 16 is the print height m of the print part 14a.
The connecting portion 14c of the type belt 14 is longer than the comb tooth 1
Transformed by 5. The character portions 14a on both sides of the print digit are kept close to the print paper 16 for a certain distance or more, and a gap is secured. If the thickness t of the comb teeth 15 is larger than the height m of the character 14a, it is more reliable. Therefore, the structure is such that the character portions 14a on both sides of the printing portion 14a in the printing step do not come into contact with the printing paper 16. Next, the paper feeding mechanism will be described.

<Paper feed mechanism> The paper feed mechanism will be described with reference to FIGS. 10, 11, 12, and 18. First
Figure 10 is a cross-sectional view of the print drum after printing the most significant digit. First
FIG. 11 is a cross-sectional view during sheet feeding. The print drum 12 has a print claw portion 12a having a maximum print digit number of 13 digits. Print drum 12
There are 15 pins 12 on the end face of the
It has a mechanism to go around in 15 steps. Two steps are used for paper feeding. Since the highest digit (13 digits) is printed, the print drum 12 rotates in the direction of the arrow. The fan-shaped paper feed drive gear 12b provided on the side surface of the print drum 12 rotates in the direction of arrow ◯ and meshes with the paper feed gear 28. Most significant digit (13
After the printing of the digit is completed, the drive pulley 9 is rotated to move to the selection step. An energization signal waveform is applied to the electromagnet 6 at an arbitrary position. As described above, the worm 11 rotates, the print drum 12 rotates in the direction of arrow .largecircle., And the paper feed drive gear 12b also rotates in the direction of arrow O.
(Because the print drum 12 does not have the print claw 12a, the hammer 13
Does not move and does not print) Paper feed gear 28 is paper feed drive gear
It receives rotation from 12b and rotates in the direction of arrow Q. Paper feed gear 2
8 is a feed roller 29 on the concentric shaft, which is made of a material such as rubber or soft resin and has a diameter larger than the outer diameter of the teeth of the paper feed gear 28.
Is fitted or is two-color molded (insert molded). The feed roller 29 also rotates in the direction of arrow Q. The printing paper 16 pressed against the pressing roller 18 to which the force due to the elastic deformation of the feeding roller 29 and the pressing shaft 21 is applied, is fed by friction in the arrow R direction. In this embodiment, the desired paper feed pitch is 2
The mechanism is such that it can be obtained by feeding the paper once. Therefore, a signal is again given to the electromagnet 6 to perform the paper feeding operation, and the print drum 12
Returns to the standby position before printing the first digit in FIG. 7, and the printing cycle for one line is completed. The home poly cam 12d pushes down the ohmic position brush 26H in the arrow X direction to bring it into contact with the common brush 26a. FIG. 18 is a time chart diagram in which an energization signal is applied to the electromagnet 6 in the shortest paper feed signal. Then, when printing the next line, the above series of operations may be repeated. Next, the paper guide will be described.

<Structure of printing paper guide> Fig. 22 is a schematic composition of the entrance portion of the printing paper 16 in the printing paper guide portion. (B) is a front view of the entrance portion of the printing paper 16 and (a) is k-
It is sectional drawing of k '. The guide of the printing paper 16 is formed by combining the frame 1 with a platen 17 separator 36 which also serves as a paper guide. Groove at relative position between frame 1 and platen 17
1a and groove 17a are attached. The groove 17a of the platen 17 has a recess 17
There is b. Separator, 36 is slidable along groove 1a of platen 1 and groove 17a of platen 17 so that groove 1
A slope 36a is provided to facilitate insertion into a and 17a. Further, there is a convex portion 36b that engages with a recess 17b provided in the groove 17a of the platen 17, and a sloped surface 36d that guides the printing paper 16 is symmetrical and has a tapered shape.

When the width of printing paper 16 is s4.

The width of frame 1 is larger than the maximum intersection of width s4 for printing paper 16.
Left and right are regulated by s6, and are regulated by gaps s8, s9 that are larger than the thickness of the printing paper 16. For the insertion opening, the slope 1b of the frame 1 and the slope of the platen 17 are arranged to facilitate insertion.
17c and 17d form a prismatic funnel shape. In this case, the separator 37 is not used.

When the width of printing paper 16 is s5.

After the frame 1 and the platen 17 are assembled, the separator 36 is inserted along the groove 1a of the frame 1 and the groove 17a of the platen 17 so that the size becomes the same as the maximum tolerance of the paper width s5. The protrusion 36b of the separator 36 is inserted by expanding the gap s10 by d1 due to elastic deformation of the platen 17, frame 1 or both, and the protrusion 36 enters the recess 17b of the platen 17. The gap widened by d1 returns to s10, and the separator 36 becomes difficult to come off and is held. The separator 36 has a slope 17c, 1
There are slopes 36c and 36d that have the same function as 7d, and there is a slope 36e that has the same function as the slope 1b of the frame 1. Separator 3
When 6 needs to be guided on both sides of the printing paper 16, the separator 36 needs only one kind.

[Effects of the Invention] As described above, according to the present invention, the belt drive means for transmitting the rotation of the motor as the drive source to the type belt and the detection wheel rotated in synchronization with the type belt are provided. It has a detector that outputs a corresponding signal, and a rotatable ink roller that presses the characters and applies ink to the characters.The layout of the characters on the character belt depends on the space used for printing. At least 2 different from typeface
Since more than one ink roller is arranged, when the ink roller faces a space type without a character, the surface of the ink roller is not transformed into a character and the load of the ink roller on the character belt is reduced. Since the characters used for printing are arranged, the load on the ink roller is the same as that for normal characters other than space characters. By arranging the space type characters alternately, the variation time of the ink roller load is shortened.
The influence of the load fluctuation on the motor becomes small, and the fluctuation range of the rotation speed of the type belt becomes small. Therefore, the runnability of the type belt is stable, and the detection wheel that is rotated in synchronization with the type belt is also stable, so the pulses detected from the detector are stable and chattering is reduced, eliminating defects due to detection errors. Was able to greatly improve the reliability of.

Also, due to the small load fluctuations on the print belt,
Since the load does not concentrate on a certain part of the type belt and that part is deformed, when printing, the center of the hammer member and the stopped printed type can be kept in the initial setting, so the center The printing quality could be greatly improved without the occurrence of the character missing due to the uneven contact of the printed characters when they did not match.

Further, by arranging a large number of space type characters, the printing speed can be greatly improved in the case of changing the space or in the printer of the type that selects the space type characters for the non-printed digits.

As described above, the practical effect of the present invention is extremely large.

[Brief description of drawings]

An embodiment of the present invention is shown in FIGS. 1 to 22. FIG. 1 is an exploded perspective view of the printer of the present invention. FIG. 2 is a schematic configuration diagram of the printer as seen from a plane. FIG. 3 is a sectional view of the switching mechanism section. FIG. 4 is a schematic side sectional view. FIG. 5 is a back sectional view for explaining the relationship between the detection wheel and the brush. FIG. 6 is an explanatory view of a differential mechanism.
7 to 9 are explanatory views showing the printing operation. Figures 10-11
The figure is an explanatory view showing the paper feeding operation. Fig. 12 is an explanatory diagram of the home position signal. Figure 13 is a perspective view of the hammer. Figure 14 is a perspective view of the print drum. FIG. 15 is an explanatory plan view of a type belt. 16th
The figure shows the type layout of the type belt. Figures 17 and 18 are time charts. Figure 19 shows the relationship between the print drum and the worm.
FIG. 20 is a partial detailed view for explaining the positions of the comb teeth. FIG. 21 is an enlarged view of the type belt in the printing state. FIG. 22 is a schematic view of the printing paper guide section. 1 …… frame 6 …… electromagnet 7 …… selection claw 9 …… drive pulley 10 …… print switching gear 11 …… worm 12 …… print drum 13 …… hammer 14 …… type belt 15 …… comb teeth 16 …… Printing paper 17 …… Platen 19 …… Driven pulley 20 …… Ink roller 22 …… Sun gear 23 …… Planet gear 24 …… Detection wheel 25 …… R detection cam 26 …… Detection brush 28 …… Paper feed gear 29… … Feed roller 33 …… Suction plate 36 …… Separator 37 …… Type belt 40 …… Driven pulley 41 …… Frame

Claims (1)

[Claims] 1. A type belt, which is provided with a large number of type letters at a predetermined pitch and is rotated so as to be orthogonal to the traveling direction of the printing paper,
In a small printer including a hammer member for pressing the desired type on the printing paper and a hammer driving unit for driving the hammer member, a belt driving unit for transmitting rotation of a motor as a driving source to the type belt. A detection wheel that is rotated in synchronism with the print belt, and outputs a signal corresponding to the print character; and a rotatable ink roller that presses the print character and applies ink to the print character. The printer is characterized in that at least two space type characters not used for printing are arranged alternately with the type characters used for printing in the arrangement state of the type characters of the type belt.