Background of the Invention
(1) Field of the Invention
[0001] The present invention relates to a developing method using a two-component type developer.
More particularly, the present invention relates to a developing method in which a
high reproducibility of letters can be attained and in reproduction of multiple fine
lines, the width of each line is constant and occurrence of so-called front end lacking
or rear end lacking is prevented.
(2) Description of the Related Art
[0002] A two-component type developer comprising a magnetic carrier and a toner is widely
used in commercial electro-photographic copying machines, and at the development of
a charge image, a magnetic brush of this developer is formed on a developing sleeve
having magnetic poles disposed therein and the magnetic brush is brought into sliding
contact with a photosensitive material having a charge image formed thereon to form
a toner image.
[0003] Many proposals have been made on conditions adopted for this development. For example,
Japanese Unexamined Patent Publication No. 59-172660 teaches that an image having
a high density and an excellent gradation can be obtained by using a two-component
type developer comprising a ferrite carrier and an electroscopic toner and adjusting
the toner concentration, the photosensitive drum/developing sleeve peripheral speed
radio and the angle of the main pole in the developing sleeve within predetermined
ranges. Furthermore, Japanese Unexamined Patent Publication No. 61-118767 teaches
that in the development using a two-component type developer, a high-quality image
having no image unevenness can be obtained by adjusting the surface potential, the
distance D-S (between the photosensitive material drum and the developing sleeve)
and the resistance value of the magnetic carrier.
[0004] Recently, Japanese Unexamined Patent Publication No. 63-208867 discloses a developing
method using a two-component type developer comprising a magnetic carrier and a toner,
in which dispersions of the image density can be eliminated by adjusting the developer
packing ratio (PD) of the developing zone, defined by the following formula, to 20
to 50%:
PD = M/(ρ x Ds) x 100
wherein M represents the amount (g/cm²) of the developer on the sleeve after passage
through the brush height-regulating portion, ρ represents the true specific gravity
(g/cm³) of the developer, and Ds represents the distance between the developing sleeve
and the electrostatic latent image recorder.
[0005] In each of the two former proposals, the characteristics of the developer and the
developing conditions are independently defined but the actual developing operations
are not comprehensively grasped, and the characteristics of the developers are defined
only under static conditions, not under practical dynamic conditions. Therefore, the
defined developing method is not satisfactorily matched to practical conditions in
a copying machine.
[0006] The latter proposal is significant in that the packing ratio of the developer in
the developing zone is taken into account. However, the contact state between the
magnetic brush of the developer and the surface of the photosensitive material under
practical developing conditions, that is, under dynamic conditions, is not satisfactorily
defined, and the defined method is not well in agreement with the practical development
method.
Summary of the Invention
[0007] We found that in a developing method using a two-component type developer, the substitution
degree of the developer in the developing zone has significant influences on the reproducibility
of fine lines irrespectively of various developing conditions, the kind of the developer
and the kind of the photosensitive material.
[0008] It is a primary object of the present invention to provide a developing method in
which in the reproduction of multiple fine lines, the width of each line is constant
and front end lacking or rear end lacking is prevented, and a high-density and high-quality
image can be formed.
[0009] Another object of the present invention is to provide a developing method in which
the reproducibility of Chinese characters and the reprodubility in the repeated reproduction
from obtained copies are improved.
[0010] In accordance with the present invention, there is provided a developing method comprising
delivering a two-component type developer comprising a magnetic carrier and a toner
by a sleeve and developing an electrostatic latent image on a photosensitive drum,
wherein developing conditions are set so that the substitution degree (R) of the developer,
defined by the following formula:
R(%) =

[(

-

)A+

] x 100 (1)
x represents the delivery quantity (g/sec) of the two-component type developer, T
represents the developing time (sec), V represents the volume (mm³) of the developing
zone, ρt represents the density (g/mm³) of the toner, ρc represents the density (g/mm³)
of the carrier, and A represents the weight ratio of the toner in the developer,
is 16.00 to 33.00%.
[0011] It is preferred that in the above-mentioned formula, the delivery quantity x be 40
to 250 g/sec, the developing time T be 0.025 to 0.28 second, and the volume V of the
developing zone be 1.15 x 10² to 28.00 x 10² mm³.
[0012] The specific volume (v/M) of the two-component type developer, which is represented
by the following formula:

=(

-

)A+

is preferably 1.5 x 10² to 3.75 x 10² mm³/g.
[0013] Furthermore, it is preferred that the density ρc of the magnetic carrier be 3.50
x 10⁻³ to 6.50 x 10⁻³ g/mm³, the density ρt of the toner be 1.00 x 10⁻³ to 1.40 x
10⁻³ g/mm³, and the weight ratio A of the toner in the developer be 0.03 to 0.06.
Brief Description of the Drawings
[0014]
Fig. 1 is a diagram showing the relation between the distance in the feed direction
and the image density of congregated fine lines, which illustrates front end lacking
or rear end lacking caused in the development of congregated lines.
Fig. 2 is a graph showing the relation between the substitution degree R of the developer
and the deviation (δ) of the line width, which is observed when the value R is changed.
Fig. 3 is a graph showing the relation between the value R and the image density (ID),
observed when the value R is changed.
Fig. 4 is a graph showing the relation between the weight ratio A of the toner and
the ratio (v/M) of the total volume (v) of one carrier particle and the toner present
around one particle of the carrier to the total weight (M) of one carrier particle
and the toner present around one particle of the carrier.
Fig. 5 is a diagram illustrating the developing method of the present invention.
Detailed Description of the Preferred Embodiments
[0015] The present invention is based on the finding that if the substitution degree (R)
of the developer, defined by the above-mentioned formula (1), is maintained within
the range of from 16.00 to 33.00%, especially from 18.75 to 32.05%, a copied image
having a high quality and an excellent reproducibility of Chinese characters at a
high image density can be obtained. Chinese characters are constructed by congregated
fine lines. According to the present invention, in the development of congregated
fine lines, the line width is kept constant in each line and front end lacking or
rear end lacking can be prevented, and a copied image having a high image quality
can be obtained.
[0016] Referring to Fig. 1 illustrating front end lacking or rear end lacking caused in
the development of congregated fine lines, the distance in the feed direction is plotted
on the abscissa and the reflection image density of a copied image of congregated
fine lines, measured by a microdensitometer, is plotted on the ordinate, to show the
relation between them. Curve (i) in Fig. 1 shows a copied image in which the line
width is constant in each line and front end lacking or rear end lacking is not caused,
curve (ii) in Fig. 1 shows a copied image in which front end lacking is conspicuous,
and curve (iii) shows a copied image in which rear end lacking is conspicuous. The
deviation (δ) of the line width in the feed direction in the reproduction of fine
lines is given by the following formula:
=

x 100 (2)
wherein A, B and C represent image densities of respective peaks appearing in order
in the feed direction.
If the value of δ is 100 or close thereto, the width is constant in each line. If
the value of δ is larger 100, this indicates occurrence of front end lacking, and
if the value of δ is smaller than 100, this indicates occurrence of rear end lacking.
[0017] In Fig. 2, the relation between the value of the substitution degree R of the developer
defined by the formula (1) and the deviation (δ) of the line width, observed when
the value of R is changed, is plotted, and in Fig. 3, the relation between the value
of R and the image density (ID), observed when the value R is changed, is plotted.
From the results shown in Figs. 2 and 3 it is understood that if the developing conditions
are set so that the value of R is within the range specified in the present invention,
the deviation of the line width can be maintained at a level of about 100% while maintaining
the image density at such a high level as 1.3 or more. In general, if R exceeds the
above range, the reproducibility of a line image is degraded, thickening of the line
width, especially the thickening of the front end, is readily caused, and the image
density tends to decrease slightly. If R is below the above-mentioned range, a blur
is readily formed in the line image, front end lacking is readily caused, and the
image density tends to decrease. On the other hand, if R is within the above-mentioned
range, an optimum combination of the image density and the image quality can be obtained
in a copied image of multiple fine lines.
[0018] The substitution degree (R) of the developer, referred to in the present invention,
is a dimensionless number and has the following meaning. Namely, the developing time
is the time required for the electrostatic latent image to pass through the volume
V of the developing zone and therefore, the value of term xT represents the delivery
weight of the two-component type developer fed into the volume of the developing zone
within the developing time T. For convenience, supposing that M is the total weight
(g) of one carrier particle and the toner present around one particle of the carrier
and v is the total volume (mm³) of one carrier particle and the toner present around
one particle of the carrier, the value of the term v/M represents the specific volume
of the carrier/toner aggregate. Accordingly, the product of both the values, that
is, xT/·v/M, represents the volume of the carrier/toner aggregate fed into the volume
of the developing zone during the developing time T. The value R obtained by dividing
this value by the volume V of the developing zone and multiplying the obtained value
by 100, which is represented by the following formula:
R =

·

x 100 (1-A)
indicates the ratio of the substitution of the volume of the developing zone by a
fresh carrier/toner aggregate (developer) within the developing time T.
[0019] Supposing that the weight ratio of the toner in the developer is A, the weight and
volume of one carrier particle are Wc and Vc, respectively, and the weight and volume
of one toner particle are Wt and Vt, respectively, the total weight M and total volume
v of one carrier particle and the toner present around one particle of the carrier
are represented by the following formulae:

The following term in these formulae indicates the number of toner particles present
around one particle of the carrier:

Supposing that the specific gravities of the carrier and toners are ρc and ρt, respectively,
they are represented by the following formulae:
ρc =

(6)
and
ρt =

(7)
[0020] It has value of v/M is calculated from the formulae (3), (4), (6) and (7), the following
formula is derived:

=

- A

+

=[

-

]A+

(8)
[0021] In Fig. 4, the relation between the weight ratio A or the toner and the value of
v/M is the formula (8) is plotted. The weight ratio A can take any value of from 0
to 1. When A is zero, v/M is the value of 1/ρc and when A is 1, v/M is the value
of 1/ρt (when A is an intermediate value, v/M is a value intermediate between 1/ρc
and 1/ρt). Namely, it is confirmed that this relation is well in agreement with the
actual state.
[0022] In the present invention, the relations of the substitution degree (R) of the developer
to various factors of the developing conditions are apparent from the above-mentioned
formula (1). Namely, as the delivery quantity x of the two-component type developer,
the developing time T and the parenthesized value in the formula (1), that is, v/M,
increase, the substitution degree (R) of the developer increases. In contrast, as
the values of x, T and v/M decrease, also the value of R decreases. On the other hand,
as the volume V of the developing zone increases, the substitution degree (R) of the
developer decreases, and as the volume V decreases, the value of R increases. Therefore,
according to the present invention, the above-mentioned developing conditions can
be set so that the substitution (R) of the developer is within the above-mentioned
range.
[0023] More specifically, the delivery quantity x of the two-component type developer can
be adjusted by the peripheral speed of the developing sleeve and the cut length of
the magnetic brush, and the delivery quantity is selected from the range of 40.00
to 250.0 g/sec, especially 85 to 220 g/sec, so that R is in the above-mentioned range.
The developing time T can be adjusted by the peripheral speed of the photosensitive
drum and the width of the developing zone, and the developing time T is selected from
the range of 0.025 to 0.28 second, especially 0.05 to 0.20 second, so that R is within
the above-mentioned range. The volume V of the developing zone is adjusted by the
width of the developing zone and the sleeve-drum distance and the volume is selected
in the range of from 1.15 x 10² to 28.00 x 10² mm³, especially 2.00 x 10² to 15.00
x 10² mm², so that R is in the above-mentioned range.
[0024] In the case where ρt and ρc are kept constant, increase of the weight ratio A of
the toner results in increase of the substitution degree (R) of the developer. It
is preferred that the parenthesized value in the formula (1), that is, the value of
v/M, be 1.5 x 10² to 3.75 x 10² mm³/g, especially 2.1 x 10² to 3.30 x 10² mm³/g.
[0025] Developing conditions will now be described in detail.
[0026] Referring to Fig. 5 illustrating the magnetic brush developing method used in the
present invention, a magnet roll 11 having many magnetic poles (N and S) 10 is contained
in a developing sleeve 12 formed of a non-magnetic material such as aluminum. A photosensitive
drum 15 comprising a substrate 13 and a electrophotographic photosensitive layer 14
formed thereon is disposed with a minute distance d
D-S from the developing sleeve 12. The developing sleeve 12 and the photosensitive drum
15 are rotatably supported on a machine frame (not shown) and they are driven so that
at the nip position, the moving directions of the sleeve 12 and drum 15 are the same
(indicated by arrows in the drawings) (the rotating directions are opposite to each
other). The developing sleeve is located at an opening of a developing device 16,
and a mixing stirrer 17 for a two-component type developer (that is, a mixture of
a toner and a magnetic carrier) 18 is arranged in the interior of the developing device
16. A toner supply mechanism 20 for supplying a toner 19 is arranged above the stirrer
17. The two-component type developer 18 is mixed and stirred by the stirrer 17 to
frictionally charge the toner. Then, the developer is fed onto the developing sleeve
12 to form a magnetic brush 21 on the surface of the sleeve 12. The length of the
magnetic brush is adjusted by a brush-cutting mechanism 22 and the magnetic brush
21 is delivered to the nip position to the electrophotographic photosensitive layer
14, and an electrostatic latent image on the photosensitive layer 14 is converted
to a visible image with the toner 19.
[0027] According to the present invention, by appropriately setting in combination such
conditions as the kind of the developer, the delivery quantity of the developer, the
developing time and the volume of the developing zone, the requirement of the formula
(1) is satisfied. This setting is accomplished, for example, in the following manner,
though the present invention is not limited by the following description.
[0028] The specific volume (v/M) of the developer is preferably adjusted to 1.5 x 10² to
3.75 x 10² mm³/g, especially preferably 2.1 x 10² to 3.30 x 10² mm³/g, as pointed
out hereinbefore.
[0029] It is preferred that the density ρc of the magnetic carrier be 3.50 x 10⁻³ to 6.50
x 10⁻³ g/mm³, especially 4.00 x 10⁻³ to 5.50 x 10⁻³ g/mm³, though the preferred density
depends on the toner concentration. Use of a ferrite type magnetic carrier is especially
preferable.
[0030] Sintered ferrite particles composed of at least one member selected from the group
consisting of zinc iron oxide (ZnFe₂O₄), yttrium iron oxide (Y₃Fe₅O₁₂), cadmium iron
oxide (CdFe₂O₄), gadolinium iron oxide (Gd₃Fe₅O₁₂), copper iron oxide (CuFe₂O₄), lead
iron oxide (PbFe₁₂O₁₉), nickel iron oxide (NiFe₂O₄), neodium iron oxide (NdFeO₃),
barium iron oxide (BaFe₁₂O₁₉), magnesium iron oxide (MgFe₂O₄), manganese iron oxide
(MnFe₂O₄) and lanthanum iron oxide (LaFeO₃) are conventionally used. Soft ferrites
comprising at least one metal component, preferably at least two metal components,
selected from the group consisting of Cu, Zn, Mg, Mn and Ni, for example, copper/zinc/magnesium
ferrite, are especially used. Among these ferrites, those satisfying the foregoing
conditions are used in the present invention.
[0031] It is preferred that the saturation magnetization of the carrier be 40 to 65 emu/g,
especially 45 to 56 emu/g. Ferrite carriers, especially spherical ferrite carriers,
satisfying the above conditions, are preferably used as the magnetic carrier. It is
preferred that the particle size of the magnetic carrier be 20 to 140µm, especially
50 to 100µm.
[0032] Of course, the electric resistance of the ferrite carrier varies according to the
chemical composition thereof, and the electric resistance of the ferrite carrier further
depends on the particulate structure, the preparation process and the kind and thickness
of the coating. It is generally preferred that the volume resistivity of the carrier
be 1 x 10¹⁰ to 5 x 10¹¹ Ω-cm, especially 4 x 10¹⁰ to 1 x 10¹¹ Ω-cm.
[0033] A toner having a density ρt of 1.00 x 10⁻³ to 1.40 x 10⁻³ g/mm³, especially 1.10
x 10⁻³ to 1.20 x 10⁻³ g/mm³, is used in the present invention, though the preferred
density depends on the density of the magnetic carrier and the toner concentration.
[0034] The toner used in the present invention is prepared by incorporating a colorant and
a charge-controlling agent, optionally together with known additives to toners, into
a fixing resin medium. It is preferred that the volume resistivity of the toner used
in the present invention be 1x 10⁸ to 3 x 10⁹ Ω-cm, especially 2 x 10⁸ to 8 x 10⁹
Ω-cm, as measured by the method described in detail hereinafter. It is preferred that
the dielectric constant of the toner be 2.5 to 4.5, especially 3.0 to 4.0.
[0035] A fixing resin medium for the toner, a colorant, a charge-controlling agent and other
additives to the toner are selected and combined so that the above-mentioned characteristics
can be obtained. As the fixing resin medium, a styrene resin, an acrylic resin and
a styrene/acrylic copolymer resin are generally used.
[0036] As the styrene monomer used for these resins, there can be mentioned monomers represented
by the following formula:

wherein R₁ represents a hydrogen atom, a lower alkyl group having up to 4 carbon
atoms, or a halogen atom, R₂ represents a substituent such as a lower alkyl group
or a halogen atom, and n is an integer of up to 2, including zero,
such as styrene, vinyltoluene, α-methylstyrene, α-chlorostyrene and vinylxylene,
and vinylnaphthalene. Among these monomers, styrene is especially preferable.
[0037] As the acrylic monomer, there can be mentioned monomers represented by the following
formula:

wherein R₃ represents a hydrogen atom or a lower alkyl group, and R₄ represents a
hydrogen atom or an alkyl group having up to 18 carbon atoms,
such as ethyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl
acrylate, 2-ethylhexyl methacrylate, acrylic acid and methacrylic acid. Instead of
these monomers, ethylenically unsaturated carboxylic acids and anhydrides thereof,
such as maleic anhydride, fumaric acid, maleic acid, crotonic acid and itaconic acid,
can be used as the acrylic monomer.
[0038] A styrene/acrylic copolymer resin is one of preferable resin media, and in this copolymer,
it is preferred that the styrene monomer (A)/acrylic monomer (B) weight ratio be from
50/50 to 90/10, especially from 60/40 to 85/15. In general, the resin used has preferably
an acid value of 0 to 25. In view of the fixing property, a resin having a glass transition
temperature (Tg) is preferably used.
[0039] Inorganic and organic pigments and dyes are used singly or in the form of a mixture
of two or more of them as the colorant to be incorporated into the resin. For example,
there can be mentioned carbon blacks such as furnace black and channel black, iron
black such as triiron tetroxide, rutile type titanium dioxide, anatase type titanium
dioxide, Phthalocyanine Blue, Phthalocyanine Green, Cadmium Yellow, Molybdenum Orange,
Pyrazolone Red, Fast Violet B and the like.
[0040] Known charge-controlling agents can be optionally used as the charge-controlling
agent in the present invention. For example, there can be used oil-soluble dyes such
as Nigrosine Base (CI 50415), Oil Black (CI 26150) and Spilon Black, 1:1 type and
2:1 type metal complex salt dyes, metal salts of naphthenic acid, fatty acids, soaps
and resin acid soaps.
[0041] Preferably, the particle size of toner particles is 8 to 14 µm, especially 10 to
12 µm, as the volume median particle size measured by Coulter Counter. The shape of
the toner particles can be an indeterminate shape as formed by the melt-kneading and
pulverizing method or a spherical shape as formed by the dispersion or suspension
polymerization method.
[0042] The weight ratio A of the toner in the developer is preferably 0.03 to 0.06, especially
preferably 0.035 to 0.055.
[0043] In order to attain the objects of the present invention, it is preferred that the
resistivity of the developer as a whole be 5 x 10⁹ to 5 x 10¹⁰ Ω-cm, especially 1
x 10¹° to 4 x 10¹⁰ Ω-cm.
[0044] As pointed out hereinbefore, it is preferred that the delivery quantity x of the
developer be 40.00 to 250.00 g/sec, especially 85 to 220 g/sec. For this purpose,
it is preferred that the flux density of the magnetic field of the magnetic poles
of the developing sleeve be 500 to 1000 G, especially 650 to 850 G, and that the peripheral
speed of the developing sleeve be 60 to 800 cm/sec, especially 90 to 450 cm/sec. The
cut length of the magnetic brush depends on the flux density, but it is preferred
that the cut length of the magnetic brush be 0.6 to 1.6 mm, especially 0.8 to 1.4
mm.
[0045] As pointed out hereinbefore, the developing time T is preferably 0.025 to 0.28 second,
especially preferably 0.05 to 0.20 second. The developing time T can be adjusted by
changing the peripheral speed of the photosensitive drum or changing the nip width
to the developer. The peripheral speed of the photosensitive drum is selected from
the range of 60 to 200 cm/sec, especially 90 to 150 cm/sec, and the nip width is selected
from the range of 5 to 17 cm, especially 8 to 12 cm.
[0046] As pointed out hereinbefore, the volume V of the developing zone is preferably 1.15
x 10² to 28.00 x 10² mm³, especially preferably 2.00 x 10² to 15.00 x 10² mm³. This
volume V can be adjusted by changing the nip width or the drum/sleeve distance (D-S).
Preferably, the distance (D-S) is selected from the range of from 0.6 to 1.6 mm, especially
the range of from 0.8 to 1.4 mm.
[0047] All of photosensitive materials customarily used in the electrophotography, for example,
a selenium photosensitive material, an amorphous silicon photosensitive material,
a zinc oxide photosensitive material, a cadmium selenide photosensitive material,
a cadmium sulfide photosensitive material and various organic photosensitive materials
can be used as the photosensitive material in the present invention.
[0048] The bias voltage applied between the developing sleeve and the conductive substrate
of the photosensitive material as another developing condition is preferably such
that the average field intensity is 100 to 1000 V/mm, especially 125 to 500 V/mm.
[0049] As is apparent from the foregoing description, according to the present invention,
by setting the developing conditions so that the substitution degree of the developer,
defined relatively to the delivery quantity of the two-component type developer, the
developing time, the volume of the developing zone, the density of the toner, the
density of the carrier and the weight ratio of the toner in the developer, is within
the specific range of 16.00 to 33.00%, the reproducibility of letters especially Chinese
characters or aggregates of fine lines, is improved, and a copied image having a high
density and a high quality can be obtained.
[0050] The effects of the present invention will now be described more clearly with reference
to the following example.
Example
[0051] The relation of the substitution degree of the developer to the formed image was
examined under the following developing conditions by using the developing apparatus
shown in Fig. 5.
Developing Conditions
Photosensitive material (D): Se, diameter = 78 mm
Sleeve (S): diameter = 38 mm
D-S Distance: 1.0 mm
Brush-cutting clearance: 1.0 mm
Density (ρt) of toner: 1.15 x 10⁻³ g/mm³
Density (ρc) of carrier: 5.00 x 10⁻³ g/mm³
Weight ratio (A) of toner: 0.045
[0052] In the forward direction development where the rotation directions of the photosensitive
material (D) and sleeve (S) were the same in the developing zone, a plurality of runs
were carried out by changing the rotation speeds of the photosensitive material (D)
and sleeve (S).
[0053] In each of these runs, the delivery quantity x (g/sec) of the developer, the developing
time T (second) and the volume V (mm³) of the developing zone were determined, and
the substitution degree R (%) of the toner was calculated from these values according
to the following formula (1) defining the substitution degree R (%) of the developer:
R(%) =

[(

-

)A+

] x 100 (1)
[0054] In each run, an image sample was prepared and the quality of the image was evaluated
relatively to the substitution degree of the developer calculated according to the
above-mentioned formula (1). For evaluation of the image quality, the image density
(ID) of the first copy and the deviation (%) of the line width were determined by
using a microdensitometer (Model PD5 supplied by Konica).
[0055] The obtained results are shown in Table 1.
Table 1
Run No. |
Delivery Quantity x (g/sec) of Developer |
Developing Time T (second) |
Volume V (mm³) of Developing Zone |
Substitution Degree R (%) of Developer |
Image |
|
|
|
|
|
I.D. |
Deviation |
Reproduction of Letters and Lines |
1 |
27.55 |
0.033 |
3.75 x 10² |
10.51 |
1.21 |
88 |
× |
2 |
40.55 |
0.058 |
5.51 x 10² |
18.75 |
1.25 |
90 |
Δ |
3 |
61.50 |
0.067 |
8.37 x 10² |
21.60 |
1.31 |
92 |
○ |
4 |
70.55 |
0.078 |
9.59 x 10² |
25.16 |
1.35 |
94 |
○ |
5 |
78.95 |
0.090 |
10.75 x 10² |
28.66 |
1.37 |
98 |
○ |
6 |
87.23 |
0.10 |
11.90 x 10² |
32.05 |
1.40 |
90 |
Δ |
7 |
90.10 |
0.11 |
12.26 x 10² |
34.10 |
1.41 |
87 |
× |
8 |
97.38 |
0.11 |
13.24 x 10² |
35.89 |
1.41 |
75 |
× |
9 |
106.32 |
0.12 |
14.41 x 10² |
39.11 |
1.43 |
69 |
× |
Note: ○: good, Δ: fair, ×: bad, |