JPH0236105B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides an ultrasonic diagnostic apparatus that corrects the brightness of an obtained image in the depth direction for each depth division. This invention relates to improvements in correction circuits.

(Prior art) Images obtained by ultrasonic diagnostic equipment are generally displayed as images whose brightness changes in relation to depth. There is. In the conventional method, the depth direction is divided into multiple stages, and the brightness is corrected for each divided area.

FIG. 2 is a block diagram showing an example of a conventional correction circuit of this type. In the figure, 1 is a reference clock generator that can selectively output two types of reference clocks with different periods, and 2 is a counter that counts the reference clocks. The reference clock generator 1 starts generating a clock in synchronization with a trigger signal Trig' in the depth direction given from the ultrasonic diagnostic apparatus. Counter 2 receives trigger signal Trig via counter reset signal generator 3.
It is reset by In the depth direction, as shown in Figure 3, there are 0, 2, 4, 6, 8, 10, 12, 14, 17,
It is divided into 20 cm sections, and the depth and reference clock correspond as shown in Figure 4. In this case, a clock with period t ₁ is input to the counter 2 for depths from 0 to 14 cm, and a clock with period t ₂ for depths from 14 cm to 20 cm.
This clock switching control is such that the output of counter 2 is 8.
In other words, it is performed using the ^23- bit signal (D) of the binary output. is the output of counter 2
The 2 ⁰ , 2 ¹ , 2 ² , and 2 ³ bit output signals become signals A, B, C, and D via the buffer 4, and the signals A and D are input to the NAND gate 5. Numeral 6 generates an integrator reset signal RST, which will be described later, and generates the reset signal RST every time the output of the counter reset signal generator 3 and the clock from the reference clock generator 1 are input. This RST is also Batsuhua 4
Sent via . 8 to 11 are multiplexers. The multiplexer 8 is supplied with eight input signals _E0 to _E7 , and selects one of the inputs according to the value (A, B, C) of the counter 2.
That is, when the value of counter 2 is 0, E ₀ is selected, when it is 1, E ₁ is selected, and in the same way, when the value is 7, E ₇ is selected.

The same applies to the multiplexer 10, but in this case, the inputs _E1 to _E8 are selected corresponding to the values 0 to 7 of the counter 2. Multiplexers 9 and 11 are input
Select and output E ₈ and E ₉ respectively. In addition, multiplexers 8 to 11 are given the INH signal,
When this signal is "0", the selection operation becomes possible. The INH signal is given the output signal (D') of the gate 5 via the inverter 7, but D' is directly given to the multiplexers 8 and 10, and the output signal (D') is given to the multiplexers 9 and 11 via the inverter 12.
D′ is given. As a result, multiplexer 8,
10, 9, and 11 become operational in a complementary manner.

Analog voltage input given to multiplexer
E ₀ to _{E 9} are set voltages for setting division points in the depth direction, and are set by dividing a reference voltage using a variable resistor. Here, E ₀ , E ₁ , E 2 , . . . , E ₉ are set corresponding to the boundary points at depths of 0, 2, ₄ , . . . , 20 cm shown in FIG.

The outputs of the multiplexers 8 and 9 are wired-ORed and input to a buffer amplifier 14, and the outputs of the other multiplexers 10 and 11 are wired-ORed and inputted to a buffer amplifier 15, respectively. A differential amplifier 16 appropriately amplifies the difference between the buffer amplifiers 14 and 15. Its output is input to first and second integrators 17 and 18 in parallel. two integrators 1
7 and 18 have different integration time constants. The output of the integrator is connected to switch 1 activated by said D signal.
9 selectively selects the summing amplifier 20.
guided by. Switch 1 for summing amplifier 20
9 and the output of buffer amplifier 14 are added. The addition output is output via the buffer amplifier 21. This signal is added to the device's video signal as a brightness signal.

In such a configuration, Ei and Ei are output from the multiplexer according to the clock count value i at counter 2.
The set input voltage of Ei+1 is selected. The summing amplifier 20 adds Ei and the voltage obtained by integrating (Ei+1-Ei), thereby obtaining a brightness signal corrected for each area. Integration in this case is performed by the first integrator 17 when i is 0 to 7, and is performed by the second integrator 18 when i is 8 or 9.

(Problem to be solved by the invention) However, in conventional circuits, the division in the depth direction is predetermined by the manufacturer and is fixed, and cannot be changed arbitrarily by the user. . Therefore, depending on the diagnostic site or diagnostic magnification, the range in which the variable resistor for setting E ₀ to _{E 9} acts appears to be too wide or too narrow, which is a drawback.

For example, correction using all variable resistors was only possible when the magnification that maximized the diagnostic depth was selected.

The present invention was made in view of these problems, and its purpose is to provide a brightness correction circuit for an ultrasonic diagnostic apparatus that allows the user to arbitrarily set the brightness variable range in the depth direction, and that has a simple configuration. The aim is to provide the following.

(Means for Solving the Problems) The present invention solves the above problems by a brightness correction method for correcting the brightness of an image in an ultrasonic diagnostic apparatus for each depth divided into multiple stages. The circuit includes means for generating a reference clock in relation to the depth direction, and means for reading the set value of the divisional depth according to the number of the reference clocks and obtaining a signal for brightness correction. In the brightness correction circuit, the means for generating the reference clock comprises:
A first mono multivibrator for determining the pulse width of the reference clock, a second mono multivibrator for determining the period of the reference clock, and a time constant of the second mono multivibrator depending on whether it is automatic or manual. a first switch for switching;
a plurality of resistance value setting means for setting a variable range in the depth direction; and a plurality of resistance value setting means connected to the first switch in the manual mode to selectively control the plurality of resistance value setting means according to the number of reference clock inputs. It is characterized by comprising a third switch that selects and connects to.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIG.
The same parts as those in the figures are indicated by the same reference numerals. In Fig. 1, 31 is the first mono multivibrator (hereinafter abbreviated as MM1) for pulse width setting, 32 is the second mono multivibrator (hereinafter abbreviated as MM2) for period setting, and 33 is the output pulse of MM1. 34 is a first analog switch, 35 is a second analog switch, 36
3 is a third analog switch, and 37 is an automatic/manual changeover switch.

MM1 is activated at the falling edge of a trigger signal Trig' (given from the main body of the apparatus) having an interval corresponding to the diagnostic depth, and is also activated by the rising edge of the output of MM2 to generate a pulse. The pulse width is determined by the time constant of external resistor _R1 and capacitor _C1 .

The pulse width of the output pulse of MM2 is determined by an external capacitor _C2 and a resistor selected and connected by analog switch 34. Pulse counter 33 is reset by the reference clock.
The first analog switch 34 is the changeover switch 3
When switch 7 is off (automatic), it is energized by the voltage +V applied through resistor R ₄ and selects the output of the second analog switch 35, and when switch 37 is on (manual), it selects the output of the second analog switch 35. ), the common voltage (0V) is applied to select the output of the third analog switch 36.

The second analog switch is the pulse counter 33
Connected to the resistor _R2 side or resistor _R3 side depending on the 23 ^- bit output. A voltage +V is applied to resistors R ₂ and R ₃ .

One end of each of ten variable resistors RV ₁ to _{RV 10} is led to the input end of the third analog switch 36 in accordance with the output of the pulse counter 33 . and,
When the value of counter 33 is 1, RV ₁ , when it is 2,
When RV ₂ , ..., 10, select RV ₁₀ . Variable resistors RV ₁ to _{RV 10} are depth-direction brightness variable range setting volumes, which are placed in parallel with the depth-direction division volume on the operation panel of the device, and their values can be set arbitrarily. It is something that can be done. The other ends of RV ₁ to RV ₁₀ are commonly connected and given a voltage of +V.

The operation in such a configuration will be explained with reference to the time charts of FIGS. 5 and 6. still,
Since the parts other than those related to the generation of the input clock of the pulse counter have the same structure as the conventional circuit shown in FIG. 2 and perform the same operations, only the operation of how reference clocks with different periods are generated will be described.

(1) When the magnification that maximizes the diagnostic depth is selected for the displayed image (1-a) When automatic is selected with the selection switch 37 The first analog switch 34 selects the output of the third analog switch 35 . The pulse counter 33 is reset by the input of the trigger signal Trig' shown in FIG.
Connected to _R2 side. MM1 due to the rising edge of the reference clock is _C1 .
Outputs a pulse with a pulse width of R ₁ time constant.
The pulse counter 33 counts this and the content becomes 1. Further, MM2 is triggered by the rising edge of the pulse and generates a pulse having a pulse width of a time constant of C ₂ ·R ₂ . At the rising edge of this pulse, MM1 is triggered again to generate a second pulse.

Similar operations are repeated thereafter, and when the eighth pulse is input to the pulse counter 33, the D signal becomes 1, and the second analog switch 35 is switched to the _R3 side. As a result, a pulse with a time constant of C ₂ and R ₃ is generated in MM2, and the pulse period changes as shown in FIG. Trigger signal after 10th pulse
The pulse counter 33 is reset by Trig' and returns to its initial state.

(1-b) In the case of manual operation When the switch 37 is turned on, the first analog switch 34 switches to the third analog switch 36.
connected to. Pulses are generated by the same operation as above, but the analog switch 36 is activated in sequence according to the value of the pulse counter 33.
In order to select RV ₁ , RV ₂ , ..., RV ₈ , the fifth
As shown in Figure C, the pulse period is C ₂ · RV ₁ ,
C ₂ · RV ₂ , C ₂ · RV ₃ , ..., C ₂ · RV ₈ .
This figure shows the case where RV ₉ and RV ₁₀ are not used.

(2) When the magnification minimizes the diagnosis depth (2-a) When the automatic mode is used The same operation as in the case (1-a) above produces pulse widths C ₁ and R ₁ as shown in Figure 6B. Pulses are output sequentially with a period of C ₂ and R ₂ . However, since the depth is shortened, the brightness adjustment resistor RV ₁ ~
During RV ₁₀ , RV ₉ and RV ₁₀ are not applied and are unrelated (2-b) In the case of manual operation The pulse width C ₁ · R ₁ is changed as shown in Fig. 6 (c) by the same operation as in (1-b) above. The pulses are sent out sequentially while changing the period as C ₂ ·RV ₁ , C ₂ ·RV ₂ , ..., C ₂ ·RV ₁₀ . In this example, all 10 variable resistors contribute.

As described above, the brightness range can be switched between automatic and manual, and in the case of manual, the user can arbitrarily set the brightness variable range.

It should be noted that the variable depth range set by the variable resistor can be configured to be displayed numerically on the panel on the device side, but since this configuration is not immediately relevant to the present invention, the explanation will be omitted here. Furthermore, the means for making the depth variable is not limited to the variable resistor as in the embodiment, but may be of a digital input type using up/down keys. Furthermore, the number of input means does not necessarily have to correspond one-to-one to the variable resistors for depth division, and a plurality of input means may correspond to one variable resistor ( Effects of the Invention) As explained above, according to the present invention, although the configuration is simple, the variable range in the depth direction of each variable resistor that corrects the brightness in the depth direction of the diagnostic image can be controlled by the user. Since the configuration can be set arbitrarily, the following effects can be obtained.

(1) Since all variable resistors can be used for brightness correction at all times regardless of the diagnostic magnification, more detailed correction is possible.

(2) Depending on the diagnosis area, a rough correction may be sufficient, and in that case, by widening the variable range of the volume, it is possible to quickly correct the brightness as desired.

(3) It is also possible to easily return to the automatic state set by the manufacturer.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an embodiment of the brightness correction circuit according to the present invention, Fig. 2 is a configuration diagram showing an example of a conventional brightness correction circuit, and Fig. 3 shows the relationship between the depth direction and brightness. 4 is a time chart of the circuit shown in FIG. 2, and FIGS. 5 and 6 are time charts for explaining the operation of the present invention. 4... Buffer, 8 to 11... Multiplexer, 14, 15... Buffer amplifier, 16... Differential amplifier, 17, 18... Integrator, 20... Summing amplifier, 21... Buffer amplifier, 31...
First mono multivibrator, 32... Second mono multivibrator, 33... Pulse counter, 34... First analog switch, 35...
Second analog switch, 36...Third analog switch, 37...Auto/manual changeover switch.

Claims (1)

[Claims] 1. A brightness correction circuit for correcting the brightness of an image in an ultrasonic diagnostic apparatus for each depth divided into multiple stages, comprising means for generating a reference clock in relation to the depth direction; In the brightness correction circuit, the brightness correction circuit includes means for reading the setting value of the division depth according to the number of reference clocks and obtaining a signal for brightness correction. a first mono multivibrator for determining the period of the reference clock; a second mono multivibrator for determining the period of the reference clock; and a first mono multivibrator for switching the time constant of the second mono multivibrator between automatic and manual modes. a switch, a plurality of resistance value setting means for setting a variable range in the depth direction, and a plurality of resistance value setting means connected to the first switch in the manual mode and controlling the plurality of resistance value setting means according to the number of reference clock inputs. 1. A brightness correction circuit for an ultrasonic diagnostic apparatus, comprising a third switch that selectively selects and connects.